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Sample records for adopt half-chair conformations

  1. EBV latency types adopt alternative chromatin conformations.

    PubMed

    Tempera, Italo; Klichinsky, Michael; Lieberman, Paul M

    2011-07-01

    Epstein-Barr Virus (EBV) can establish latent infections with distinct gene expression patterns referred to as latency types. These different latency types are epigenetically stable and correspond to different promoter utilization. Here we explore the three-dimensional conformations of the EBV genome in different latency types. We employed Chromosome Conformation Capture (3C) assay to investigate chromatin loop formation between the OriP enhancer and the promoters that determine type I (Qp) or type III (Cp) gene expression. We show that OriP is in close physical proximity to Qp in type I latency, and to Cp in type III latency. The cellular chromatin insulator and boundary factor CTCF was implicated in EBV chromatin loop formation. Combining 3C and ChIP assays we found that CTCF is physically associated with OriP-Qp loop formation in type I and OriP-Cp loop formation in type III latency. Mutations in the CTCF binding site located at Qp disrupt loop formation between Qp and OriP, and lead to the activation of Cp transcription. Mutation of the CTCF binding site at Cp, as well as siRNA depletion of CTCF eliminates both OriP-associated loops, indicating that CTCF plays an integral role in loop formation. These data indicate that epigenetically stable EBV latency types adopt distinct chromatin architectures that depend on CTCF and mediate alternative promoter targeting by the OriP enhancer. PMID:21829357

  2. Interactome Analysis Reveals Ezrin Can Adopt Multiple Conformational States*

    PubMed Central

    Viswanatha, Raghuvir; Wayt, Jessica; Ohouo, Patrice Y.; Smolka, Marcus B.; Bretscher, Anthony

    2013-01-01

    Ezrin, a member of the ezrin-radixin-moesin family (ERM), is an essential regulator of the structure of microvilli on the apical aspect of epithelial cells. Ezrin provides a linkage between membrane-associated proteins and F-actin, oscillating between active/open and inactive/closed states, and is regulated in part by phosphorylation of a C-terminal threonine. In the open state, ezrin can bind a number of ligands, but in the closed state the ligand-binding sites are inaccessible. In vitro analysis has proposed that there may be a third hyperactivated form of ezrin. To gain a better understanding of ezrin, we conducted an unbiased proteomic analysis of ezrin-binding proteins in an epithelial cell line, Jeg-3. We refined our list of interactors by comparing the interactomes using quantitative mass spectrometry between wild-type ezrin, closed ezrin, open ezrin, and hyperactivated ezrin. The analysis reveals several novel interactors confirmed by their localization to microvilli, as well as a significant class of proteins that bind closed ezrin. Taken together, the data indicate that ezrin can exist in three different conformational states, and different ligands “perceive” ezrin conformational states differently. PMID:24151071

  3. Conformational analysis of primary ethylene ozonide by gradient and multiconfigurational scf calculations

    NASA Astrophysics Data System (ADS)

    Ruoff, Peter; Almlöf, Jan; Sæbø, Svem

    1980-06-01

    Four conformers of ethylene primary ozonide have been studied by ab initio gradient and MC SCF calculations, using gaussian-type basis functions. The MC SCF results indicate that the conformers are not as close in energy as suggested from single-determinant SCF calculations. The oxygen-oxygen and carbon-oxygen half-chair structures are much lower in energy than the carbon-carbon half-chair.

  4. Mycobacterium tuberculosis acyl carrier protein synthase adopts two different pH-dependent structural conformations

    SciTech Connect

    Gokulan, Kuppan; Aggarwal, Anup; Shipman, Lance; Besra, Gurdyal S.; Sacchettini, James C.

    2011-07-01

    Bacterial acyl carrier protein synthase plays an essential role in the synthesis of fatty acids, nonribosomal peptides and polyketides. In Mycobacterium tuberculosis, AcpS or group I phosphopentatheine transferase exhibits two different structural conformations depending upon the pH. The crystal structures of acyl carrier protein synthase (AcpS) from Mycobacterium tuberculosis (Mtb) and Corynebacterium ammoniagenes determined at pH 5.3 and pH 6.5, respectively, are reported. Comparison of the Mtb apo-AcpS structure with the recently reported structure of the Mtb AcpS–ADP complex revealed that AcpS adopts two different conformations: the orthorhombic and trigonal space-group structures show structural differences in the α2 helix and in the conformation of the α3–α4 connecting loop, which is in a closed conformation. The apo-AcpS structure shows electron density for the entire model and was obtained at lower pH values (4.4–6.0). In contrast, at a higher pH value (6.5) AcpS undergoes significant conformational changes, resulting in disordered regions that show no electron density in the AcpS model. The solved structures also reveal that C. ammoniagenes AcpS undergoes structural rearrangement in two regions, similar to the recently reported Mtb AcpS–ADP complex structure. In vitro reconstitution experiments show that AcpS has a higher post-translational modification activity between pH 4.4 and 6.0 than at pH values above 6.5, where the activity drops owing to the change in conformation. The results show that apo-AcpS and AcpS–ADP adopt different conformations depending upon the pH conditions of the crystallization solution.

  5. Mycobacterium tuberculosis acyl carrier protein synthase adopts two different pH-dependent structural conformations

    SciTech Connect

    Gokulan, Kuppan; Aggarwal, Anup; Shipman, Lance; Besra, Gurdyal S.; Sacchettini, James C.

    2011-09-20

    The crystal structures of acyl carrier protein synthase (AcpS) from Mycobacterium tuberculosis (Mtb) and Corynebacterium ammoniagenes determined at pH 5.3 and pH 6.5, respectively, are reported. Comparison of the Mtb apo-AcpS structure with the recently reported structure of the Mtb AcpS-ADP complex revealed that AcpS adopts two different conformations: the orthorhombic and trigonal space-group structures show structural differences in the {alpha}2 helix and in the conformation of the {alpha}3-{alpha}4 connecting loop, which is in a closed conformation. The apo-AcpS structure shows electron density for the entire model and was obtained at lower pH values (4.4-6.0). In contrast, at a higher pH value (6.5) AcpS undergoes significant conformational changes, resulting in disordered regions that show no electron density in the AcpS model. The solved structures also reveal that C. ammoniagenes AcpS undergoes structural rearrangement in two regions, similar to the recently reported Mtb AcpS-ADP complex structure. In vitro reconstitution experiments show that AcpS has a higher post-translational modification activity between pH 4.4 and 6.0 than at pH values above 6.5, where the activity drops owing to the change in conformation. The results show that apo-AcpS and AcpS-ADP adopt different conformations depending upon the pH conditions of the crystallization solution.

  6. Calmodulin Adopts an Extended Conformation when Interacting with L-Selectin in Membranes

    PubMed Central

    Deng, Wei; Putkey, John A.; Li, Renhao

    2013-01-01

    Calmodulin, an intracellular calcium-binding protein, is thought to regulate ectodomain shedding of many membrane proteins, but the underlying molecular mechanism has remained unclear. Basing on a solution structure of calcium-loaded calmodulin in complex with a L-selectin fragment that contains a portion of its transmembrane domain, Gifford et al. (University of Calgary) recently suggested that calmodulin regulates L-selectin shedding by binding directly to a portion of the L-selectin transmembrane domain in a compact conformation. Using fluorescently labeled calmodulin, we show however that calmodulin adopts a distinctly different and much more extended conformation when it binds to the CLS peptide (i.e. the entire transmembrane and cytoplasmic domains of L-selectin) reconstituted in the phosphatidylcholine liposome with micromolar dissociation constant and in a calcium-independent manner. Calmodulin adopts a similarly extended conformation in a ternary complex with the N-terminal FERM domain of moesin and CLS reconstituted in the phospholipid liposome that mimics the native membrane environment. These results indicate that calmodulin does not bind directly to the transmembrane domain of L-selectin. Understanding the association of calmodulin with L-selectin helps to shed light on the mechanisms underlying regulation of ectodomain shedding. PMID:23658780

  7. The HAMP Signal Relay Domain Adopts Multiple Conformational States through Collective Piston and Tilt Motions

    PubMed Central

    Zhu, Lizhe; Bolhuis, Peter G.; Vreede, Jocelyne

    2013-01-01

    The HAMP domain is a linker region in prokaryotic sensor proteins and relays input signals to the transmitter domain and vice versa. Functional as a dimer, the structure of HAMP shows a parallel coiled-coil motif comprising four helices. To date, it is unclear how HAMP can relay signals from one domain to another, although several models exist. In this work, we use molecular simulation to test the hypothesis that HAMP adopts different conformations, one of which represents an active, signal-relaying configuration, and another an inactive, resting state. We first performed molecular dynamics simulation on the prototype HAMP domain Af1503 from Archaeoglobus fulgidus. We explored its conformational space by taking the structure of the A291F mutant disabling HAMP activity as a starting point. These simulations revealed additional conformational states that differ in the tilt angles between the helices as well as the relative piston shifts of the helices relative to each other. By enhancing the sampling in a metadynamics set up, we investigated three mechanistic models for HAMP signal transduction. Our results indicate that HAMP can access additional conformational states characterized by piston motion. Furthermore, the piston motion of the N-terminal helix of one monomer is directly correlated with the opposite piston motion of the C-terminal helix of the other monomer. The change in piston motion is accompanied by a change in tilt angle between the monomers, thus revealing that HAMP exhibits a collective motion, i.e. a combination of changes in tilt angles and a piston-like displacement. Our results provide insights into the conformational changes that underlie the signaling mechanism involving HAMP. PMID:23468603

  8. Adoption

    MedlinePlus

    ... the birth nor adoptive parents know the others' identities. Other adoptions are handled more openly. Open adoptions, ... desire to seek out more information about the identity of the birth family. Most of us (whether ...

  9. Beyond spectral tuning: human cone visual pigments adopt different transient conformations for chromophore regeneration.

    PubMed

    Srinivasan, Sundaramoorthy; Cordomí, Arnau; Ramon, Eva; Garriga, Pere

    2016-03-01

    Human red and green visual pigments are seven transmembrane receptors of cone photoreceptor cells of the retina that mediate color vision. These pigments share a very high degree of homology and have been assumed to feature analogous structural and functional properties. We report on a different regeneration mechanism among red and green cone opsins with retinal analogs using UV-Vis/fluorescence spectroscopic analyses, molecular modeling and site-directed mutagenesis. We find that photoactivated green cone opsin adopts a transient conformation which regenerates via an unprotonated Schiff base linkage with its natural chromophore, whereas red cone opsin forms a typical protonated Schiff base. The chromophore regeneration kinetics is consistent with a secondary retinal uptake by the cone pigments. Overall, our findings reveal, for the first time, structural differences in the photoactivated conformation between red and green cone pigments that may be linked to their molecular evolution, and support the proposal of secondary retinal binding to visual pigments, in addition to binding to the canonical primary site, which may serve as a regulatory mechanism of dark adaptation in the phototransduction process. PMID:26387074

  10. Affinity-Tagged Miniprion Derivatives Spontaneously Adopt Protease-Resistant Conformations

    PubMed Central

    Supattapone, Surachai; Nguyen, Hoang-Oanh B.; Muramoto, Tamaki; Cohen, Fred E.; DeArmond, Stephen J.; Prusiner, Stanley B.; Scott, Michael

    2000-01-01

    An abridged PrP molecule of 106 amino acids designated PrP106 can form infectious miniprions in transgenic (Tg) mice (29). Addition of six-histidine (His6) affinity tags to selective sites within PrP106 resulted unexpectedly in new PrP proteins that spontaneously adopted protease-resistant conformations when expressed in neuroblastoma cells and Tg mice. Acquisition of protease resistance depended on the length, charge, and placement of the affinity tag. Introduction of the disease-linked mutation E200K into the sequence of PrP106(140/6His) increased the recovery of protease-resistant PrP fivefold, whereas introduction of the mutations C213A and Δ214–220 did not affect the recovery of protease-resistant PrP. Treatment of cultured cells expressing affinity-tagged PrP106 mutants with polypropyleneimine dendrimer rendered these proteins sensitive to protease digestion in a manner similar to wild-type PrPSc. We conclude that certain affinity-tagged PrP106 proteins spontaneously fold into conformations partially resembling, yet distinct from, wild-type PrPSc. These proteins might be useful tools in the identification of new disease-causing mutations as well as for screening compounds for therapeutic efficacy. PMID:11090193

  11. [Adoption].

    ERIC Educational Resources Information Center

    Pawl, Jeree, Ed.; And Others

    1990-01-01

    This newsletter theme issue addresses adoption and the young child's life. Contributors suggest ways in which practitioners in many professions and settings can better understand and support adoptive families. The first article, "Adoption, 1990" by Barbara F. Nordhaus and Albert J. Solnit, reviews the history of adoption and notes obstacles to…

  12. Structural basis for the varying propensities of different amino acids to adopt the collagen conformation.

    PubMed

    Raman, S Sundar; Gopalakrishnan, R; Wade, R C; Subramanian, V

    2011-03-24

    Although previous experimental studies have shown the positional preference of different amino acids (AAs) to form a stable triple helical collagen motif, the structural basis for the variations in the sequence and the positional propensity has not been systematically investigated. Thus, we have here probed the origin of the structural stability offered by the 20 naturally occurring AAs to collagen by means of classical molecular dynamics (MD) simulation. Simulations were carried out on 39 collagen-like peptides employing a host-guest approach. The results show that the propensity of the different AAs to adopt collagen-like conformations depends primarily on their ϕ and ψ angle preferences. Changes in these angles upon substitution of different AAs in the X(AA) and Y(AA) positions in the canonical ((Gly-X(AA)-Y(AA))(7))(3) motif dictate the formation of interchain hydrogen bonds, solvent interactions, and puckering of neighboring imino acids and, thus, the structural stability of the collagen. The role of solvent-mediated hydrogen bonds in the stabilization of collagen has also been elucidated from the MD simulations. In addition to the conventional hydrogen bonds known to be present in collagen, a hitherto unidentified direct interchain hydrogen bond, between the X(AA) N-H group and the Hyp O-H group of the neighboring chain, was observed during the simulations. Its occupancy was ∼36% when Leu was present at the X(AA) position. PMID:21361324

  13. T Cell Receptor Engagement Triggers Its CD3ε and CD3ζ Subunits to Adopt a Compact, Locked Conformation

    PubMed Central

    Risueño, Ruth M.; Schamel, Wolfgang W. A.; Alarcón, Balbino

    2008-01-01

    How the T cell antigen receptor (TCR) discriminates between molecularly related peptide/Major Histocompatibility Complex (pMHC) ligands and converts this information into different possible signaling outcomes is still not understood. One current model proposes that strong pMHC ligands, but not weak ones, induce a conformational change in the TCR. Evidence supporting this comes from a pull-down assay that detects ligand-induced binding of the TCR to the N-terminal SH3 domain of the adapter protein Nck, and also from studies with a neoepitope-specific antibody. Both methods rely on the exposure of a polyproline sequence in the CD3ε subunit of the TCR, and neither indicates whether the conformational change is transmitted to other CD3 subunits. Using a protease-sensitivity assay, we now show that the cytoplasmic tails of CD3ε and CD3ζ subunits become fully protected from degradation upon TCR triggering. These results suggest that the TCR conformational change is transmitted to the tails of CD3ε and CD3ζ, and perhaps all CD3 subunits. Furthermore, the resistance to protease digestion suggests that CD3 cytoplasmic tails adopt a compact structure in the triggered TCR. These results are consistent with a model in which transduction of the conformational change induced upon TCR triggering promotes condensation and shielding of the CD3 cytoplasmic tails. PMID:18320063

  14. Premutation huntingtin allele adopts a non-B conformation and contains a hot spot for DNA damage

    SciTech Connect

    Jarem, Daniel A.; Delaney, Sarah

    2011-12-09

    Highlights: Black-Right-Pointing-Pointer First structural and thermodynamic analysis of premutation allele of HD. Black-Right-Pointing-Pointer Premutation allele of HD adopts a stem-loop non-B conformation. Black-Right-Pointing-Pointer Healthy and premutation length stem-loops are hyper-susceptible to oxidative damage. Black-Right-Pointing-Pointer Stability of stem-loop structures increases linearly with repeat length. Black-Right-Pointing-Pointer Thermodynamic stability, not the ability to adopt non-B conformation, distinguishes DNA prone to expansion from stable DNA. -- Abstract: The expansion of a CAG trinucleotide repeat (TNR) sequence has been linked to several neurological disorders, for example, Huntington's disease (HD). In HD, healthy individuals have 5-35 CAG repeats. Those with 36-39 repeats have the premutation allele, which is known to be prone to expansion. In the disease state, greater than 40 repeats are present. Interestingly, the formation of non-B DNA conformations by the TNR sequence is proposed to contribute to the expansion. Here we provide the first structural and thermodynamic analysis of a premutation length TNR sequence. Using chemical probes of nucleobase accessibility, we found that similar to (CAG){sub 10}, the premutation length sequence (CAG){sub 36} forms a stem-loop hairpin and contains a hot spot for DNA damage. Additionally, calorimetric analysis of a series of (CAG){sub n} sequences, that includes repeat tracts in both the healthy and premutation ranges, reveal that thermodynamic stability increases linearly with the number of repeats. Based on these data, we propose that while non-B conformations can be formed by TNR tracts found in both the healthy and premutation allele, only sequences containing at least 36 repeats have sufficient thermodynamic stability to contribute to expansion.

  15. E-selectin ligand complexes adopt an extended high-affinity conformation

    PubMed Central

    Preston, Roland C.; Jakob, Roman P.; Binder, Florian P.C.; Sager, Christoph P.; Ernst, Beat; Maier, Timm

    2016-01-01

    E-selectin is a cell-adhesion molecule of the vascular endothelium that promotes essential leukocyte rolling in the early inflammatory response by binding to glycoproteins containing the tetrasaccharide sialyl Lewisx (sLex). Efficient leukocyte recruitment under vascular flow conditions depends on an increased lifetime of E-selectin/ligand complexes under tensile force in a so-called catch-bond binding mode. Co-crystal structures of a representative fragment of the extracellular E-selectin region with sLex and a glycomimetic antagonist thereof reveal an extended E-selectin conformation, which is identified as a high-affinity binding state of E-selectin by molecular dynamics simulations. Small-angle X-ray scattering experiments demonstrate a direct link between ligand binding and E-selectin conformational transition under static conditions in solution. This permits tracing a series of concerted structural changes connecting ligand binding to conformational stretching as the structural basis of E-selectin catch-bond-mediated leukocyte recruitment. The detailed molecular view of the binding site paves the way for the design of a new generation of selectin antagonists. This is of special interest, since their therapeutic potential was recently demonstrated with the pan-selectin antagonists GMI-1070 (Rivipansel). PMID:26117840

  16. Lys63-linked ubiquitin chain adopts multiple conformational states for specific target recognition

    PubMed Central

    Liu, Zhu; Gong, Zhou; Jiang, Wen-Xue; Yang, Ju; Zhu, Wen-Kai; Guo, Da-Chuan; Zhang, Wei-Ping; Liu, Mai-Li; Tang, Chun

    2015-01-01

    A polyubiquitin comprises multiple covalently linked ubiquitins and recognizes myriad targets. Free or bound to ligands, polyubiquitins are found in different arrangements of ubiquitin subunits. To understand the structural basis for polyubiquitin quaternary plasticity and to explore the target recognition mechanism, we characterize the conformational space of Lys63-linked diubiquitin (K63-Ub2). Refining against inter-subunit paramagnetic NMR data, we show that free K63-Ub2 exists as a dynamic ensemble comprising multiple closed and open quaternary states. The quaternary dynamics enables K63-Ub2 to be specifically recognized in a variety of signaling pathways. When binding to a target protein, one of the preexisting quaternary states is selected and stabilized. A point mutation that shifts the equilibrium between the different states modulates the binding affinities towards K63-Ub2 ligands. This conformational selection mechanism at the quaternary level may be used by polyubiquitins of different lengths and linkages for target recognition. DOI: http://dx.doi.org/10.7554/eLife.05767.001 PMID:26090905

  17. X-ray and 1H-NMR spectroscopic studies of the structures and conformations of the new nootropic agents RU-35929, RU-47010 and RU-35965

    NASA Astrophysics Data System (ADS)

    Amato, Maria E.; Bandoli, Giuliano; Casellato, Umberto; Pappalardo, Giuseppe C.; Toja, Emilio

    1990-10-01

    The crystal and molecular structures of the nootropics (±)1-benzenesulphonyl-2-oxo-5-ethoxypyrrolidine ( 1), (±)1-(3-pyridinylsulphonyl)-2-oxo-5-ethoxypyrrolidine ( 2) and (±)1-benzenesulphonyl-2-oxo-5-isopropyloxypyrrolidine ( 3) have been determined by X-ray analysis. The solution conformation of 1, 2 and 3 has been investigated by 1H NMR spectroscopy. In the solid state, the main feature consists of the similar structural parameters and conformations, with the exception of the conformation adopted by the 5-ethoxy moiety which changes on passing from 1 to 2. The solid state overall enveloped conformation of the 2-pyrrolidinone ring for the three nootropics is found to be retained in solution on the basis of NMR evidence. Comparison between calculated and experimental coupling constant values shows that one of the two possible puckered opposite conformational isomers (half-chair shapes) occurs in solution. The relative pharmacological potencies of 1, 2 and 3 cannot therefore be interpreted in terms of the different conformation features presently detectable by available experimental methods.

  18. c-Abl Tyrosine Kinase Adopts Multiple Active Conformational States in Solution

    PubMed Central

    2016-01-01

    Protein tyrosine kinases of the Abl family have diverse roles in normal cellular regulation and drive several forms of leukemia as oncogenic fusion proteins. In the crystal structure of the inactive c-Abl kinase core, the SH2 and SH3 domains dock onto the back of the kinase domain, resulting in a compact, assembled state. This inactive conformation is stabilized by the interaction of the myristoylated N-cap with a pocket in the C-lobe of the kinase domain. Mutations that perturb these intramolecular interactions result in kinase activation. Here, we present X-ray scattering solution structures of multidomain c-Abl kinase core proteins modeling diverse active states. Surprisingly, the relative positions of the regulatory N-cap, SH3, and SH2 domains in an active myristic acid binding pocket mutant (A356N) were virtually identical to those of the assembled wild-type kinase core, indicating that Abl kinase activation does not require dramatic reorganization of the downregulated core structure. In contrast, the positions of the SH2 and SH3 domains in a clinically relevant imatinib-resistant gatekeeper mutant (T315I) appear to be reconfigured relative to their positions in the wild-type protein. Our results demonstrate that c-Abl kinase activation can occur either with (T315I) or without (A356N) global allosteric changes in the core, revealing the potential for previously unrecognized signaling diversity. PMID:27166638

  19. Gradient and mc scf calculations of the conformers and the formation of primary ethylene ozonide

    NASA Astrophysics Data System (ADS)

    Ruoff, Peter; Sæbø, Svein; Almlöf, Jan

    1981-11-01

    The confonners of primary ethylene ozonide have been studied by ab initio gradient and MC SCF calculations. At the MC SCF level they are more spread in energy than in SCF calculations. The planar conformer, carbon-carbon half chair and the oxygen envelope are much higher m energy than the other conformers. The MC SCF activation energy for cyclo-addition of ozone and ethylene is 91-99 kJ/mole.

  20. The hexameric helicase DnaB adopts a nonplanar conformation during translocation.

    PubMed

    Itsathitphaisarn, Ornchuma; Wing, Richard A; Eliason, William K; Wang, Jimin; Steitz, Thomas A

    2012-10-12

    DNA polymerases can only synthesize nascent DNA from single-stranded DNA (ssDNA) templates. In bacteria, the unwinding of parental duplex DNA is carried out by the replicative DNA helicase (DnaB) that couples NTP hydrolysis to 5' to 3' translocation. The crystal structure of the DnaB hexamer in complex with GDP-AlF(4) and ssDNA reported here reveals that DnaB adopts a closed spiral staircase quaternary structure around an A-form ssDNA with each C-terminal domain coordinating two nucleotides of ssDNA. The structure not only provides structural insights into the translocation mechanism of superfamily IV helicases but also suggests that members of this superfamily employ a translocation mechanism that is distinct from other helicase superfamilies. We propose a hand-over-hand mechanism in which sequential hydrolysis of NTP causes a sequential 5' to 3' movement of the subunits along the helical axis of the staircase, resulting in the unwinding of two nucleotides per subunit. PMID:23022319

  1. Exhaustive Metropolis Monte Carlo sampling and analysis of polyalanine conformations adopted under the influence of hydrogen bonds.

    PubMed

    Podtelezhnikov, Alexei A; Wild, David L

    2005-10-01

    We propose a novel Metropolis Monte Carlo procedure for protein modeling and analyze the influence of hydrogen bonding on the distribution of polyalanine conformations. We use an atomistic model of the polyalanine chain with rigid and planar polypeptide bonds, and elastic alpha carbon valence geometry. We adopt a simplified energy function in which only hard-sphere repulsion and hydrogen bonding interactions between the atoms are considered. Our Metropolis Monte Carlo procedure utilizes local crankshaft moves and is combined with parallel tempering to exhaustively sample the conformations of 16-mer polyalanine. We confirm that Flory's isolated-pair hypothesis (the steric independence between the dihedral angles of individual amino acids) does not hold true in long polypeptide chains. In addition to 3(10)- and alpha-helices, we identify a kink stabilized by 2 hydrogen bonds with a shared acceptor as a common structural motif. Varying the strength of hydrogen bonds, we induce the helix-coil transition in the model polypeptide chain. We compare the propensities for various hydrogen bonding patterns and determine the degree of cooperativity of hydrogen bond formation in terms of the Hill coefficient. The observed helix-coil transition is also quantified according to Zimm-Bragg theory. PMID:16049911

  2. The stringent factor RelA adopts an open conformation on the ribosome to stimulate ppGpp synthesis.

    PubMed

    Arenz, Stefan; Abdelshahid, Maha; Sohmen, Daniel; Payoe, Roshani; Starosta, Agata L; Berninghausen, Otto; Hauryliuk, Vasili; Beckmann, Roland; Wilson, Daniel N

    2016-07-27

    Under stress conditions, such as nutrient starvation, deacylated tRNAs bound within the ribosomal A-site are recognized by the stringent factor RelA, which converts ATP and GTP/GDP to (p)ppGpp. The signaling molecules (p)ppGpp globally rewire the cellular transcriptional program and general metabolism, leading to stress adaptation. Despite the additional importance of the stringent response for regulation of bacterial virulence, antibiotic resistance and persistence, structural insight into how the ribosome and deacylated-tRNA stimulate RelA-mediated (p)ppGpp has been lacking. Here, we present a cryo-EM structure of RelA in complex with the Escherichia coli 70S ribosome with an average resolution of 3.7 Å and local resolution of 4 to >10 Å for RelA. The structure reveals that RelA adopts a unique 'open' conformation, where the C-terminal domain (CTD) is intertwined around an A/T-like tRNA within the intersubunit cavity of the ribosome and the N-terminal domain (NTD) extends into the solvent. We propose that the open conformation of RelA on the ribosome relieves the autoinhibitory effect of the CTD on the NTD, thus leading to stimulation of (p)ppGpp synthesis by RelA. PMID:27226493

  3. A critical base pair in k-turns determines the conformational class adopted, and correlates with biological function.

    PubMed

    Huang, Lin; Wang, Jia; Lilley, David M J

    2016-06-20

    k-turns are commonly-occurring motifs that introduce sharp kinks into duplex RNA, thereby facilitating tertiary contacts. Both the folding and conformation of k-turns are determined by their local sequence. k-turns fall into two conformational classes, called N3 and N1, that differ in the pattern of hydrogen bonding in the core. We show here that this is determined by the basepair adjacent to the critical G•A pairs. We determined crystal structures of a series of Kt-7 variants in which this 3b,3n position has been systematically varied, showing that this leads to a switch in the conformation. We have previously shown that the 3b,3n position also determines the folding characteristics of the k-turn, i.e. whether or not the k-turn can fold in the presence of metal ions alone. We have analyzed the distribution of 3b,3n sequences from four classes of k-turns from ribosomes, riboswitches and U4 snRNA, finding a strong conservation of properties for a given k-turn type. We thus demonstrate a strong association between biological function, 3b,3n sequence and k-turn folding and conformation. This has strong predictive power, and can be applied to the modeling of large RNA architectures. PMID:27016741

  4. A critical base pair in k-turns determines the conformational class adopted, and correlates with biological function

    PubMed Central

    Huang, Lin; Wang, Jia; Lilley, David M. J.

    2016-01-01

    k-turns are commonly-occurring motifs that introduce sharp kinks into duplex RNA, thereby facilitating tertiary contacts. Both the folding and conformation of k-turns are determined by their local sequence. k-turns fall into two conformational classes, called N3 and N1, that differ in the pattern of hydrogen bonding in the core. We show here that this is determined by the basepair adjacent to the critical G•A pairs. We determined crystal structures of a series of Kt-7 variants in which this 3b,3n position has been systematically varied, showing that this leads to a switch in the conformation. We have previously shown that the 3b,3n position also determines the folding characteristics of the k-turn, i.e. whether or not the k-turn can fold in the presence of metal ions alone. We have analyzed the distribution of 3b,3n sequences from four classes of k-turns from ribosomes, riboswitches and U4 snRNA, finding a strong conservation of properties for a given k-turn type. We thus demonstrate a strong association between biological function, 3b,3n sequence and k-turn folding and conformation. This has strong predictive power, and can be applied to the modeling of large RNA architectures. PMID:27016741

  5. Post-Translational Phosphorylation of Serine 74 of Human Deoxycytidine Kinase Favors the Enzyme Adopting the Open Conformation Making It Competent for Nucleoside Binding and Release

    SciTech Connect

    Hazra, Saugata; Szewczak, Andrzej; Ort, Stephan; Konrad, Manfred; Lavie, Arnon

    2012-03-26

    Deoxycytidine kinase (dCK) uses either ATP or UTP as a phosphoryl donor to catalyze the phosphorylation of nucleoside acceptors. The kinetic properties of human dCK are modulated in vivo by phosphorylation of serine 74. This residue is a part of the insert region and is distant from the active site. Replacing the serine with a glutamic acid (S74E variant) can mimic phosphorylation of Ser74. To understand how phosphorylation affects the catalytic properties of dCK, we examined the S74E variant of dCK both structurally and kinetically. We observe that the presence of a glutamic acid at position 74 favors the adoption by the enzyme of the open conformation. Glu74 stabilizes the open conformation by directly interacting with the indole side chain of Trp58, a residue that is in the proximity of the base of the nucleoside substrate. The open dCK conformation is competent for the binding of nucleoside but not for phosphoryl transfer. In contrast, the closed conformation is competent for phosphoryl transfer but not for product release. Thus, dCK must make the transition between the open and closed states during the catalytic cycle. We propose a reaction scheme for dCK that incorporates the transition between the open and closed states, and this serves to rationalize the observed kinetic differences between wild-type dCK and the S74E variant.

  6. Glycopeptide-membrane interactions: glycosyl enkephalin analogues adopt turn conformations by NMR and CD in amphipathic media.

    PubMed

    Palian, Michael M; Boguslavsky, V I; O'Brien, David F; Polt, Robin

    2003-05-14

    Four enkephalin analogues (Tyr-D-Thr-Gly-Phe-Leu-Ser-CONH(2), 1, and the related O-linked glycopeptides bearing the monosaccharide beta-glucose, 2, the disaccharide beta-maltose, 3, and the trisaccharide beta-maltotriose, 4) were synthesized, purified by HPLC, and biophysical studies were conducted to examine their interactions with membrane model systems. Glycopeptide 2 has been previously reported to penetrate the blood-brain barrier (BBB), and produce potent analgesia superior to morphine in mice (J. Med. Chem.2000, 43, 2586-90 and J. Pharm. Exp. Ther. 2001, 299, 967-972). The parent peptide and its three glycopeptide derivatives were studied in aqueous solution and in the presence of micelles using 2-D NMR, CD, and molecular mechanics (Monte Carlo studies). Consistent with previous conformational studies on cyclic opioid agonist glycopeptides, it was seen that glycosylation did not significantly perturb the peptide backbone in aqueous solution, but all four compounds strongly associated with 5-30 mM SDS or DPC micelles, and underwent profound membrane-induced conformational changes. Interaction was also observed with POPC:POPE:cholesterol lipid vesicles (LUV) in equilibrium dialysis experiments. Although the peptide backbones of 1-4 possessed random coil structures in water, in the presence of the lipid phase they each formed a nearly identical pair of structures, all with a stable beta-turn motif at the C-terminus. Use of spin labels (Mn(2+) and 5-DOXYL-stearic acid) allowed for the determination of the position and orientation of the compounds relative to the surface of the micelle. PMID:12733923

  7. Modeling and experiment reveal an unexpected stereoelectronic effect on conformation and scalar couplings of alpha-aminoorganostannanes, with possible relevance to the tin-lithium exchange reaction.

    PubMed

    Santiago, Marcelina; Low, Eddy; Chambournier, Gilles; Gawley, Robert E

    2003-10-31

    The solution conformation of N-methyl-2-(tributylstannyl)piperidines has been determined through the use of vicinal 119Sn-13C coupling constants, revealing a conformational distortion caused by an unexpected stereoelectronic effect in some cases. Specifically, the "equatorial" conformer is distorted into a half-chair, in which the nitrogen lone pair eclipses the C-Sn bond. This distortion, which "costs" approximately 1 kcal/mol, correlates with a conformational dependence of geminal 119Sn-15N couplings and a possible correlation with reactivity in the tin-lithium exchange reaction. PMID:14575474

  8. The HIV-1 Rev response element (RRE) adopts alternative conformations that promote different rates of virus replication

    PubMed Central

    Sherpa, Chringma; Rausch, Jason W.; Le Grice, Stuart F.J.; Hammarskjold, Marie-Louise; Rekosh, David

    2015-01-01

    The HIV Rev protein forms a complex with a 351 nucleotide sequence present in unspliced and incompletely spliced human immunodeficiency virus (HIV) mRNAs, the Rev response element (RRE), to recruit the cellular nuclear export receptor Crm1 and Ran-GTP. This complex facilitates nucleo-cytoplasmic export of these mRNAs. The precise secondary structure of the HIV-1 RRE has been controversial, since studies have reported alternative structures comprising either four or five stem-loops. The published structures differ only in regions that lie outside of the primary Rev binding site. Using in-gel SHAPE, we have now determined that the wt NL4-3 RRE exists as a mixture of both structures. To assess functional differences between these RRE ‘conformers’, we created conformationally locked mutants by site-directed mutagenesis. Using subgenomic reporters, as well as HIV replication assays, we demonstrate that the five stem-loop form of the RRE promotes greater functional Rev/RRE activity compared to the four stem-loop counterpart. PMID:25855816

  9. Conformational Analysis of a Dermatan Sulfate-Derived Tetrasaccharide by NMR, Molecular Modeling, and Residual Dipolar Couplings

    PubMed Central

    Silipo, Alba; Zhang, Zhenqing; Cañada, F. Javier; Molinaro, Antonio

    2014-01-01

    The solution conformation behavior of a dermatan-derived tetrasaccharide—ΔHexA-(1→3)-GalNAc4S-β-(1→4)-IdoA-α-(1→3)-red-GalNAc4S (S is a sulfate group)—has been explored by means of NMR spectroscopy, especially by NOE-based conformational analysis. The tetrasaccharide was present as four species, two of which are chemically different in the anomeric orientation of the reducing 2-deoxy-2-acetamido-galactose (red-GalNAc) residue, while the other two are the result of different conformations of the iduronic acid (IdoA) unit. The two α–-interconverting anomers were present in a 0.6:1 ratio. Ring conformations have been defined by analysis of 3JH,H coupling constants and interresidual NOE contacts. Both 2-deoxy-2-acetamido-galactose (GalNAc) residues were found in the 4C1 chair conformation, the unsaturated uronic acid (Δ-Hex A) adopts a strongly predominant half-chair 1H2 conformation, while the IdoA residue exists either in the 1C4 chair or in the 2S0 skewed boat geometries, in a 4:1 ratio. There is a moderate flexibility of Φ and Ψ torsions as suggested by nuclear Overhauser effects (NOEs), molecular modeling (MM), and molecular dynamics (MD) studies. This was further investigated by residual dipolar couplings (RDCs). One-bond C–H RDCs (1DC,H) and long-range H–H (3DH,H) RDCs were measured for the tetrasaccharide in a phage solution and interpreted in combination with restrained MD simulation. The RDC-derived data substantially confirmed the validity of the conformer distribution resulting from the NOE-derived simulations, but allowed an improved definition of the conformational behavior of the oligosaccharides in solution. In summary, the data show a moderate flexibility of the four tetrasaccharide species at the central glycosidic linkage. Differences in the shapes of species with the IdoA in skew and in chair conformations and in the distribution of the sulfate groups have also been highlighted. PMID:18072186

  10. Permeabilization and fusion of uncharged lipid vesicles induced by the HIV-1 fusion peptide adopting an extended conformation: dose and sequence effects.

    PubMed Central

    Pereira, F B; Goñi, F M; Muga, A; Nieva, J L

    1997-01-01

    The peptide HIV(arg), corresponding to a sequence of 23 amino acid residues at the N-terminus of HIV-1 gp41 (LAV1a strain), has the capacity to destabilize negatively charged large unilamellar vesicles. As revealed by infrared spectroscopy, the peptide associated with those vesicles showed conformational polymorphism: in the absence of cations the main structure was a pore-forming alpha-helix, whereas in the presence of Ca2+ the conformation switched to a fusogenic, predominantly extended beta-type structure. Here we show that an extended structure can also be involved in electrically neutral vesicle destabilization induced by the HIV-1 fusion peptide when it binds the vesicle from the aqueous phase. In the absence of cations, neutral liposomes composed of phosphatidylcholine, phosphatidylethanolamine, and cholesterol (molar ratio 1:1:1) selected for an extended structure that became fusogenic in a dose-dependent fashion. At subfusogenic doses this structure caused the release of trapped 8-aminonaphtalene-1,3,6-trisulfonic acid sodium salt/p-xylenebis(pyridinium)bromide from liposomes, indicating the existence of a peptide-mediated membrane destabilizing process before and independent of the development of fusion. When compared to HIV(arg), the fusion activity of HIV(ala) (bearing the R22 --> A substitution) was reduced by 70%. Fusogenicity was completely abolished when a second substitution (V2 --> E) was included to generate HIV(ala-E2), a sequence representing the N-terminus of an inactive gp41. However, the three sequences associated with vesicles to the same extent, and the three adopted a similar extended structure in the membrane. Whereas 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene emission anisotropy was unaffected by the three peptides, DPH emission anisotropy in membranes was increased only by the fusogenic sequences. Taken together, our observations strongly argue that it is not an alpha-helical but an extended structure adopted by the HIV-1

  11. Improved Atomistic Monte Carlo Simulations Demonstrate that Poly-L-Proline Adopts Heterogeneous Ensembles of Conformations of Semi-Rigid Segments Interrupted by Kinks

    PubMed Central

    Radhakrishnan, Aditya; Vitalis, Andreas; Mao, Albert H.; Steffen, Adam T.; Pappu, Rohit V.

    2012-01-01

    Poly-L-proline (PLP) polymers are useful mimics of biologically relevant proline-rich sequences. Biophysical and computational studies of PLP polymers in aqueous solutions are challenging because of the diversity of length scales and the slow time scales for conformational conversions. We describe an atomistic simulation approach that combines an improved ABSINTH implicit solvation model, with conformational sampling based on standard and novel Metropolis Monte Carlo moves. Refinements to forcefield parameters were guided by published experimental data for proline-rich systems. We assessed the validity of our simulation results through quantitative comparisons to experimental data that were not used in refining the forcefield parameters. Our analysis shows that PLP polymers form heterogeneous ensembles of conformations characterized by semi-rigid, rod-like segments interrupted by kinks, which result from a combination of internal cis peptide bonds, flexible backbone ψ-angles, and the coupling between ring puckering and backbone degrees of freedom. PMID:22329658

  12. Structural and functional analysis of the NF-kappa B p65 C terminus. An acidic and modular transactivation domain with the potential to adopt an alpha-helical conformation.

    PubMed

    Schmitz, M L; dos Santos Silva, M A; Altmann, H; Czisch, M; Holak, T A; Baeuerle, P A

    1994-10-14

    The p65 subunit of the NF-kappa B transcription factor contains in its C-terminal 120 amino acids at least two transcription activation domains. One domain (TA1) is contained within only the 30 C-terminal amino acids. Structural studies employing CD and NMR spectroscopy revealed that the TA1 domain is unstructured. NMR analysis of a protein corresponding to the C-terminal 123 amino acids also showed a random coil conformation. However, a portion of TA1 was found to adopt an alpha-helical conformation in the presence of hydrophobic solvents. Transcriptional analysis of point mutants revealed the functional importance of two evolutionary conserved sequence repeats, which are located in the conditionally alpha-helical region of TA1. These repeats acted synergistically in transcription activation. The inhibitory effect of some mutants indicated secondary structure constraints on TA1 in intact cells. Inverting the sequence of two acidic activation domains significantly reduced their transactivating potential, suggesting that amino acid composition is not solely essential for activity; a defined primary structure is necessary as well. Acidic sequence motifs related in primary structure and squelching activity to those of TA1 are present in the activation domains of VP16, c-Rel, and several other transcription factors. We propose a model suggesting that primarily unstructured acidic activation domains can adopt a secondary structure upon contacting their target molecules by an "induced fit" mechanism. PMID:7929265

  13. Conformations of 1-heptene secondary ozonide as studied by low temperature FT-IR spectroscopy

    NASA Astrophysics Data System (ADS)

    Bariseviciute, R.; Ceponkus, J.; Sablinskas, V.; Kimtys, L.

    2007-11-01

    Conformational diversity of the 1-heptene secondary ozonides (SOZ) in solid neat films as well as isolated in Ar or CO 2 matrices was studied by the means of FT-IR absorption spectroscopy. The ozonization reaction was performed at 77 K in the neat films of the reactants. The spectra of the ozonide were analyzed by combining the experimental data with the results of theoretical calculations performed at B3LYP 6-311++G (3df, 3pd) level. It was found that the samples of 1-heptene secondary ozonide exist as a mixture of three dominating conformers. The most stable conformer is the one with O-O half-chair configuration of the five membered ring, the aliphatic radical attached to the ring in equatorial position and the aliphatic chain being in gauche (∠OCCC ≈ -60°) position. The other two stable conformers are equatorial with aliphatic chain in anti (∠OCCC ≈ 180°) and gauche (∠OCCC ≈ 60°) positions. It was found from Van't Hoff plots that Δ H of the equatorial anti conformer is equal to 0.24 ± 0.03 kJ/mol. The experimental value of Δ H is in reasonable accordance to the calculated one - 0.5 kJ/mol.

  14. rac-2-tert-Butyl-2,4,5,6,6-penta-chloro-cyclo-hex-3-en-1-one.

    PubMed

    Maharramov, Abel M; Allahverdiyev, Mirza A; Mammadov, Elmar Y; Askerova, Ayten R; Rashidov, Bahruz A

    2011-04-01

    The title compound, C(10)H(11)Cl(5)O, is a chiral mol-ecule with two stereogenic centres. However, it crystallizes as a racemate. One of enanti-omers reveals the relative configuration (2S*,5R*). The cyclo-hexene ring adopts a half-chair conformation. PMID:21754158

  15. rac-2-tert-Butyl-2,4,5,6,6-penta­chloro­cyclo­hex-3-en-1-one

    PubMed Central

    Maharramov, Abel M.; Allahverdiyev, Mirza A.; Mammadov, Elmar Y.; Askerova, Ayten R.; Rashidov, Bahruz A.

    2011-01-01

    The title compound, C10H11Cl5O, is a chiral mol­ecule with two stereogenic centres. However, it crystallizes as a racemate. One of enanti­omers reveals the relative configuration (2S*,5R*). The cyclo­hexene ring adopts a half-chair conformation. PMID:21754158

  16. 40 CFR 93.154 - Conformity analysis.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Conformity analysis. 93.154 Section 93... General Federal Actions to State or Federal Implementation Plans § 93.154 Conformity analysis. Any Federal... choose to adopt the analysis of another Federal agency or develop its own analysis in order to make...

  17. 40 CFR 51.854 - Conformity analysis.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Conformity analysis. 51.854 Section 51... Federal Actions to State or Federal Implementation Plans § 51.854 Conformity analysis. Link to an... for various aspects of a project, a Federal agency may choose to adopt the analysis of another...

  18. Strengthening Adoption Practice, Listening to Adoptive Families

    ERIC Educational Resources Information Center

    Atkinson, Anne; Gonet, Patricia

    2007-01-01

    In-depth interviews with 500 adoptive families who received postadoption services through Virginia's Adoptive Family Preservation (AFP) program paint a richly detailed picture of the challenges adoptive families face and what they need to sustain adoption for many years after finalization. Findings document the need for support in a variety of…

  19. Crystal structure of 16-hy­droxy-4,4,10,13,14-penta­methyl-17-(6-methyl­hept-5-en-2-yl)-4,5,6,9,10,11,12,13,14,15,16,17-dodeca­hydro-1H-cyclo­penta­[a]phenanthren-3(2H)-one

    PubMed Central

    Ge, Jun-Jun; Chen, Pian; Ye, Xiao-Xia

    2015-01-01

    The title compound, C30H48O2, contains a fused four-ring triterpenoid system. In the mol­ecule, the two cyclo­hexane rings adopt a chair conformation and a twist boat conformation, respectively, the central cyclo­hexene ring adopts a half-chair conformation whereas the five membered ring adopts an envelope conformation. In the crystal, O—H⋯O hydrogen bonds between the hy­droxy and carbonyl groups of adjacent mol­ecules link the mol­ecules into supra­molecular chains propagating along the b-axis direction. PMID:26279910

  20. Medical Issues in Adoption

    MedlinePlus

    ... to Know About Zika & Pregnancy Medical Issues in Adoption KidsHealth > For Parents > Medical Issues in Adoption Print ... or emotional abuse of the child continue Agency Adoptions If you adopt through an agency, you might ...

  1. Trichodermaerin: a diterpene lactone from Trichoderma asperellum.

    PubMed

    Chantrapromma, Suchada; Jeerapong, Chotika; Phupong, Worrapong; Quah, Ching Kheng; Fun, Hoong-Kun

    2014-04-01

    The title compound, C20H28O3, known as 'trichodermaerin' [systematic name: (4E)-4,9,15,16,16-penta-methyl-6-oxa-tetra-cyclo-[10.3.1.0(1,10).0(5,9)]hexa-dec-4-ene-7,13-dione], is a diterpene lactone which was isolated from Trichoderma asperellum. The structure has a tetra-cycic 6-5-7-5 ring system, with the cyclo-hexa-none ring adopting a twisted half-chair conformation and the cyclo-pentane ring adopting a half-chair conformation, whereas the cyclo-heptene and tetra-hydro-furan-anone rings are in chair and envelope (with the methyl-substituted C atom as the flap) conformations, respectively. The three-dimensional architecture is stabilized by C-H⋯O inter-actions. PMID:24826124

  2. Conformations and Conformational Processes of Hexahydrobenzazocines by NMR and DFT Studies.

    PubMed

    Musielak, Bogdan; Holak, Tad A; Rys, Barbara

    2015-09-18

    Conformational processes that occur in hexahydrobenzazocines have been studied with the (1)H and (13)C dynamic nuclear magnetic resonance (DNMR) spectroscopy. The coalescence effects are assigned to two different conformational processes: the ring-inversion of the ground-state conformations and the interconversion between two different conformers. The barriers for these processes are in the range of 42-52 and 42-43 kJ mol(-1), respectively. Molecular modeling on the density functional theory (DFT) level and the gauge invariant atomic orbitals (GIAO)-DFT calculations of isotropic shieldings and coupling constants for the set of low-energy conformations were compared with the experimental NMR data. The ground-state of all compounds in solution is the boat-chair (BC) conformation. The BC form adopts two different conformations because the nitrogen atom can be in the boat or chair parts of the BC structure. These two conformers are engaged in the interconversion process. PMID:26317238

  3. Conformational Landscape of Nicotinoids: Solving the "conformational - Rity" of Anabasine

    NASA Astrophysics Data System (ADS)

    Lesarri, Alberto; Cocinero, Emilio J.; Evangelisti, Luca; Suenram, Richard D.; Caminati, Walther; Grabow, Jens-Uwe

    2010-06-01

    The conformational landscape of the alkaloid anabasine (neonicotine) has been investigated using rotational spectroscopy and ab initio calculations. The results allow a detailed comparison of the structural properties of the prototype piperidinic and pyrrolidinic nicotinoids (anabasine vs. nicotine). Anabasine adopts two most stable conformations in isolation conditions, for which we determined accurate rotational and nuclear quadrupole coupling parameters. The preferred conformations are characterized by an equatorial pyridine moiety and additional N-H equatorial stereochemistry at the piperidine ring (Eq-Eq). The two rings of anabasine are close to a bisecting arrangement, with the observed conformations differing in a ca. 180° rotation of the pyridine subunit, denoted either Syn or Anti. The preference of anabasine for the Eq-Eq-Syn conformation has been established by relative intensity measurements (Syn/Anti˜5(2)). The conformational preferences of free anabasine are directed by a N\\cdot\\cdot\\cdotH-C weak hydrogen bond interaction between the nitrogen lone pair at piperidine and the closest hydrogen bond in pyridine, with N\\cdot\\cdot\\cdotN distances ranging from 4.750 Å (Syn) to 4.233 Å (Anti). R. J. Lavrich, R. D. Suenram, D. F. Plusquellic and S. Davis, 58^th OSU Int. Symp. on Mol. Spectrosc., Columbus, OH, 2003, Comm. RH13.

  4. Conformational preferences for some 3-(4‧-substituted phenylsulfonyl)-1-methyl-2-piperidones through spectroscopic and theoretical studies

    NASA Astrophysics Data System (ADS)

    Olivato, Paulo R.; Santos, Jean M. M.; Cerqueira, Carlos R.; Vinhato, Elisângela; Zukerman-Schpector, Julio; Ng, Seik Weng; Tiekink, Edward R. T.; Colle, Maurizio Dal

    2012-11-01

    The analysis of the infrared (IR) carbonyl band of some 3-(4'-substituted phenylsulfonyl)-1-methyl-2-piperidones 1-5 bearing as substituents: OMe 1, Me 2, H 3, Cl 4 and NO25, supported by B3LYP/6-31G(d,p) calculations along with NBO analysis (for 1, 3 and 5) and X-ray diffraction (for 5), indicated the existence of three stable conformations i.e. quasi-axial (q-ax), syn-clinal (s-cl) and quasi-equatorial (q-eq). In the gas phase, the q-ax conformer is calculated as the most stable (ca. 88%) and the least polar, the s-cl conformer is less stable (ca. 12%) but more polar, and the q-eq conformer is the least stable (ca. 1%) and the most polar of the three conformers evaluated. The sum of the most important orbital interactions from NBO analysis and the trend of the electrostatic interactions accounts for the relative populations as well as for the νCO frequencies of the q-ax, s-cl and q-eq conformers calculated in the gas phase. The unique IR νCO band in CCl4 may be ascribed to the most stable q-ax conformer. The more intense (60%) high frequency doublet component in CHCl3 may be assigned to the summing up of the least stable q-eq and the less stable s-cl conformers, as their frequencies are almost coincident. The occurrence of only a single νCO band in both CH2Cl2 and CH3CN supports the fact that the νCO band of the two more polar conformers appear as a single band. Additional support to this rationalization is given by the single point PCM method, which showed a progressive increase of the q-eq + s-cl/q-ax population ratio going from the gas phase to CCl4, to CHCl3, to CH2Cl2 and to CH3CN. X-ray single crystal analysis of 5 indicates that this compound displays a quasi-axial geometry with respect to the [Odbnd Csbnd CHsbnd S] moiety, and that the 2-piperidone ring assumes a slightly distorted half-chair conformation. In the crystal packing, molecules of 5 are arranged into supramolecular layers linked through Csbnd H⋯O interactions along with

  5. Adoption and Korea.

    ERIC Educational Resources Information Center

    Chun, Byung Hoon

    1989-01-01

    Because of Korean attitudes towards adoption and other reasons, attempts to promote intracountry adoption have met with limited success, and intercountry adoption is used as an alternative way of meeting children's needs. (RJC)

  6. Adopted Children and Discipline

    MedlinePlus

    ... a Pediatrician Family Life Medical Home Family Dynamics Adoption & Foster Care Communication & Discipline Types of Families Media ... Your Community Healthy Children > Family Life > Family Dynamics > Adoption & Foster Care > Adopted Children & Discipline Family Life Listen ...

  7. Adoption & Foster Care

    MedlinePlus

    ... Children > Family Life > Family Dynamics > Adoption & Foster Care Adoption & Foster Care Article Body ​Each year, many children join families through adoption and foster care. These families may face unique ...

  8. Attitudinal Conformity and Anonymity

    ERIC Educational Resources Information Center

    Tyson, Herbert; Kaplowitz, Stan

    1977-01-01

    Tested college students for conformity when conditions contributing to conformity were absent. Found that social pressures (responding in public, being surveyed by fellow group members) are necessary to produce conformity. (RL)

  9. The Family of Adoption.

    ERIC Educational Resources Information Center

    Pavao, Joyce Maguire

    This book aims to provide a broad framework within which to think about adoption as a whole system, so that everyone involved will learn to feel some empathy for the other members of the adoption process. The book, written by a family and adoption therapist who was adopted as an infant, describes predictable developmental stages and challenges for…

  10. Bis(1,2,3,4-tetra-hydro-quinoline-1-thio-carbon-yl) disulfide.

    PubMed

    Srinivasan, N; Thirumaran, S; Selvanayagam, S

    2012-12-01

    In the title compound, C20H20N2S4, the N-containing six-membered rings of the two tetra-hydro-quinoline moieties adopt half-chair conformations. Intra-molecular C-H⋯S hydrogen bonding stabilizes the mol-ecular structure. In the crystal, mol-ecules associate via weak C-H⋯π inter-actions. PMID:23476260

  11. Conformational implications of asparagine-linked glycosylation.

    PubMed Central

    Imperiali, B; Rickert, K W

    1995-01-01

    The effects of cotranslational protein modification on the process of protein folding are poorly understood. Time-resolved fluorescence energy transfer has been used to assess the impact of glycosylation on the conformational dynamics of flexible oligopeptides. The peptide sequences examined are selected from glycoproteins of known three-dimensional structure. The energy transfer modulation associated with N-linked glycosylation is consistent with the glycopeptides sampling different conformational profiles in water. Results show that glycosylation causes the modified peptides to adopt a different ensemble of conformations, and for some peptides this change may lead to conformations that are more compact and better approximate the conformation of these peptides in the final folded protein. This result further implies that cotranslational glycosylation can trigger the timely formation of structural nucleation elements and thus assist in the complex process of protein folding. PMID:7816856

  12. Tabu search based strategies for conformational search.

    PubMed

    Stepanenko, Svetlana; Engels, Bernd

    2009-10-29

    This paper presents an application of the new nonlinear global optimization routine gradient only tabu search (GOTS) to conformational search problems. It is based on the tabu search strategy which tries to determine the global minimum of a function by the steepest descent-modest ascent strategy. The refinement of ranking procedure of the original GOTS method and the exploitation of simulated annealing elements are described, and the modifications of the GOTS algorithm necessary to adopt it to conformation searches are explained. The utility of the GOTS for conformational search problems is tested using various examples. PMID:19769347

  13. Tabu Search Based Strategies for Conformational Search

    NASA Astrophysics Data System (ADS)

    Stepanenko, Svetlana; Engels, Bernd

    2009-09-01

    This paper presents an application of the new nonlinear global optimization routine gradient only tabu search (GOTS) to conformational search problems. It is based on the tabu search strategy which tries to determine the global minimum of a function by the steepest descent-modest ascent strategy. The refinement of ranking procedure of the original GOTS method and the exploitation of simulated annealing elements are described, and the modifications of the GOTS algorithm necessary to adopt it to conformation searches are explained. The utility of the GOTS for conformational search problems is tested using various examples.

  14. 17α-Acet­oxy-11β-hy­droxy-6α-methyl­pregn-4-ene-3,20-dione

    PubMed Central

    Yousuf, Sammer; Bano, Saira; Choudhary, M. Iqbal

    2012-01-01

    The title compound, C24H34O5, a fungal-transformed metabolite of the injecta­ble contraceptive medroxyprogesterone acetate, consists of four fused rings (A, B, C and D; steroid labelling). Ring A exists in a half-chair conformation while trans-fused rings B and C adopt chair conformations. The five-membered ring D adopts an envelope conformation with the C atom bound to the methyl group at the flap. In the crystal, adjacent mol­ecules are linked by O—H⋯O and C—H⋯O hydrogen bonds, forming infinite chains along the a axis. PMID:22807835

  15. Crystal structure of cholest-5-en-3β-yl 3-(2,4-dimeth­oxy-3-methyl­phen­yl)prop-2-enoate

    PubMed Central

    Bugenhagen, Bernhard; Munk, Ariane; Vill, Volkmar; Al Jasem, Yosef; Thiemann, Thies

    2015-01-01

    In the title compound, C39H58O4, the steroid rings A and C adopt a chair conformation, while ring B adopts a half-chair conformation, and ring D has an envelope conformation, with the methyl-substituted C atom as the flap. In the crystal, mol­ecules pack within layers parallel to (100), with their long axis parallel to the [101] direction. Adjacent layers are linked via C—H⋯O hydrogen bonds and C—H⋯π inter­actions, forming a three-dimensional framework. PMID:25878888

  16. Questions about Adoption

    MedlinePlus

    ... Español Text Size Email Print Share Questions About Adoption Page Content Article Body What's the best way to handle my child's questions about her adoption? Many parents want to know when is the ...

  17. What's Happening in Adoption?

    ERIC Educational Resources Information Center

    Gallagher, Ursula M.

    1975-01-01

    Reviews current issues in adoption: termination of parental rights, rights of unwed fathers, subsidized adoption, the recent influx of Vietnamese children, black market babies, agency accountability in placing children, the right of the adoptee to know his biological parents. (ED)

  18. Single Parent Adoptive Homes.

    ERIC Educational Resources Information Center

    Shireman, Joan F.

    1996-01-01

    Reviews research and reports on a longitudinal study of 15 single-parent adoptive homes over a 14-year period that demonstrated that these homes have the capacity to be successful adoptive placements. Identifies unique characteristics of single-parent adoptive homes, and notes the need for additional research to identify children for whom these…

  19. Adoption and Identity.

    ERIC Educational Resources Information Center

    Lieberman, E. James

    1998-01-01

    Discusses how adoption responds to ancient questions about origins. Maintains that one's identity hinges on actual relationships more than on pedigree and genes. Discusses reasons for informing a child about his or her adoption. Suggests that adoption is a constructive process involving too many worrisome warnings and anxiety-raising advice by the…

  20. The Effect of Family Communication Patterns on Adopted Adolescent Adjustment

    PubMed Central

    Rueter, Martha A.

    2008-01-01

    Adoption and family communication both affect adolescent adjustment. We proposed that adoption status and family communication interact such that adopted adolescents in families with certain communication patterns are at greater risk for adjustment problems. We tested this hypothesis using a community-based sample of 384 adoptive and 208 nonadoptive families. Adolescents in these families were, on average, 16 years of age. The results supported our hypothesis. Adopted adolescents were at significantly greater risk for adjustment problems compared to nonadopted adolescents in families that emphasized conformity orientation without conversation orientation and in families that emphasized neither conformity nor conversation orientation. Adolescents in families emphasizing conversation orientation were at lower risk for adjustment problems, regardless of adoption status. PMID:19649145

  1. The Transracial Adoption Paradox

    PubMed Central

    Lee, Richard M.

    2008-01-01

    The number of transracial adoptions in the United States, particularly international adoptions, is increasing annually. Counseling psychology as a profession, however, is a relatively silent voice in the research on and practice of transracial adoption. This article presents an overview of the history and research on transracial adoption to inform counseling psychologists of the set of racial and ethnic challenges and opportunities that transracial adoptive families face in everyday living. Particular attention is given to emergent theory and research on the cultural socialization process within these families. PMID:18458794

  2. Conformational readout of RNA by small ligands

    PubMed Central

    Kligun, Efrat; Mandel-Gutfreund, Yael

    2013-01-01

    RNA molecules have highly versatile structures that can fold into myriad conformations, providing many potential pockets for binding small molecules. The increasing number of available RNA structures, in complex with proteins, small ligands and in free form, enables the design of new therapeutically useful RNA-binding ligands. Here we studied RNA ligand complexes from 10 RNA groups extracted from the protein data bank (PDB), including adaptive and non-adaptive complexes. We analyzed the chemical, physical, structural and conformational properties of binding pockets around the ligand. Comparing the properties of ligand-binding pockets to the properties of computed pockets extracted from all available RNA structures and RNA-protein interfaces, revealed that ligand-binding pockets, mainly the adaptive pockets, are characterized by unique properties, specifically enriched in rare conformations of the nucleobase and the sugar pucker. Further, we demonstrate that nucleotides possessing the rare conformations are preferentially involved in direct interactions with the ligand. Overall, based on our comprehensive analysis of RNA-ligand complexes, we suggest that the unique conformations adopted by RNA nucleotides play an important role in RNA recognition by small ligands. We term the recognition of a binding site by a ligand via the unique RNA conformations “RNA conformational readout.” We propose that “conformational readout” is a general way by which RNA binding pockets are recognized and selected from an ensemble of different RNA states. PMID:23618839

  3. Fake conformal symmetry in conformal cosmological models

    NASA Astrophysics Data System (ADS)

    Jackiw, R.; Pi, So-Young

    2015-03-01

    We examine the local conformal invariance (Weyl invariance) in tensor-scalar theories used in recently proposed conformal cosmological models. We show that the Noether currents associated with Weyl invariance in these theories vanish. We assert that the corresponding Weyl symmetry does not have any dynamical role.

  4. Companion animal adoption study.

    PubMed

    Neidhart, Laura; Boyd, Renee

    2002-01-01

    To better understand the outcomes of companion animal adoptions, Bardsley & Neidhart Inc. conducted a series of 3 surveys over a 1-year period with dog and cat owners who had adopted their pet through either a (a) Luv-A-Pet location, (b) Adopt-a-thon, or (c) traditional shelter. This article suggests opportunities to improve owners' perceptions of their pets and the adoption process through (a) providing more information before adoption about pet health and behaviors, (b) providing counseling to potential adopters to place pets appropriately, and (c) educating adopters to promote companion animal health and retention. Results demonstrate that the pet's relationship to the family unit, such as where the pet sleeps and how much time is spent with the pet, is related to the amount of veterinary care the companion animal receives, and to long-term retention. Satisfaction and retention are attributed to the pet's personality, compatibility, and behavior, rather than demographic differences among adopters or between adoption settings. The age of the companion animal at adoption, the intended recipient, and presence of children in the home also play a role. Health problems were an issue initially for half of all adopted pets, but most were resolved within 12 months. Roughly one fourth of adopters who no longer have their companion animal said their pet died. Characteristics of pets that died support the contention that spaying and neutering profoundly affects a companion animal's life span. Although retention is similar for dogs and cats, mortality is higher among cats in the first year after adoption. PMID:12578739

  5. Does Your Annual Financial Report Conform?

    ERIC Educational Resources Information Center

    Foster, Charles W.

    1977-01-01

    Requirements for consideration of the Certificate of Conformance award sponsored by the Association of School Business Officials to encourage school districts to adopt and use generally accepted accounting and reporting principles for all funds used in the financial management of the school systems. (Author/MLF)

  6. Toward Focusing Conformational Ensembles on Bioactive Conformations: A Molecular Mechanics/Quantum Mechanics Study.

    PubMed

    Avgy-David, Hannah H; Senderowitz, Hanoch

    2015-10-26

    The identification of bound conformations, namely, conformations adopted by ligands when binding their target is critical for target-based and ligand-based drug design. Bound conformations could be obtained computationally from unbound conformational ensembles generated by conformational search tools. However, these tools also generate many nonrelevant conformations thus requiring a focusing mechanism. To identify such a mechanism, this work focuses on a comparison of energies and structural properties of bound and unbound conformations for a set of FDA approved drugs whose complexes are available in the PDB. Unbound conformational ensembles were initially obtained with three force fields. These were merged, clustered, and reminimized using the same force fields and four QM methods. Bound conformations of all ligands were represented by their crystal structures or by approximations to these structures. Energy differences were calculated between global minima of the unbound state or the Boltzmann averaged energies of the unbound ensemble and the approximated bound conformations. Ligand conformations which resemble the X-ray conformation (RMSD < 1.0 Å) were obtained in 91%-97% and 96%-98% of the cases using the ensembles generated by the individual force fields and the reminimized ensembles, respectively, yet only in 52%-56% (original ensembles) and 47%-65% (reminimized ensembles) as global energy minima. The energy window within which the different methods identified the bound conformation (approximated by its closest local energy minimum) was found to be at 4-6 kcal/mol with respect to the global minimum and marginally lower with respect to a Boltzmann averaged energy of the unbound ensemble. Better approximations to the bound conformation obtained with a constrained minimization using the crystallographic B-factors or with a newly developed Knee Point Detection (KPD) method gave lower values (2-5 kcal/mol). Overall, QM methods gave lower energy differences than

  7. Associations between Family Communication Patterns, Sibling Closeness, and Adoptive Status

    PubMed Central

    Samek, Diana R.; Rueter, Martha A.

    2011-01-01

    Previous research has demonstrated the protective effect of family and sibling closeness on child adjustment, but fewer studies have investigated how closeness is promoted within families. Guided by Family Communication Patterns Theory, we tested the association between family communication and sibling emotional and behavioral closeness, and whether adoptive status moderated this relationship. Participating families included 616 adoptive and non-adoptive families with two adolescent children. Hypotheses were tested using structural equation modeling. Sibling closeness was highest in families that emphasized both conversation and conformity and lowest in families that emphasized only conversation or neither conversation nor conformity. Emotional and behavioral closeness were differentially associated with adoption status, sibling age, and sibling gender. Few moderating effects of adoption status were found. Post hoc analyses showed moderating effects of sibling gender composition. PMID:21984844

  8. Single Parent Adoption.

    ERIC Educational Resources Information Center

    Administration for Children, Youth, and Families (DHHS), Washington, DC.

    Presenting two views of the single-parent family, this pamphlet includes an article by two researchers (William Feigelman and Arnold R. Silverman) and a short statement by a single adoptive parent (Amanda Richards). The first paper summarizes earlier research on single-parent adoptions and discusses the results of a nationwide survey of 713…

  9. Crystal structure of bis­[3-meth­oxy-17β-estra-1,3,5(10)-trien-17-yl] oxalate

    PubMed Central

    Harrison, William T. A.; Nahar, Lutfun; Turner, Alan B.

    2014-01-01

    In the title compound, C40H50O6, a symmetrical steroid oxalate diester, the dihedral angle between the CO2 planes of the oxalate linker is 61.5 (5)° and the C—C bond length is 1.513 (6) Å. The steroid B, C and D rings adopt half-chair, chair and envelope conformations, respectively, in both halves of the mol­ecule, which adopts an overall shallow V-shaped conformation. In the crystal, mol­ecules are linked by weak C—H⋯O inter­actions, forming a three-dimensional network. PMID:25249855

  10. Parenting Your Adopted Teenager

    MedlinePlus

    ... https: / / www. childwelfare. gov/ pubs/ f- openadopt/ .) The Internet and the explosion of social media sites (e. ... 4 Howard, J. (2012). Untangling the web: The Internet’s transformative impact on adoption . New York, NY: Evan ...

  11. Adoption and Sibling Rivalry

    MedlinePlus

    ... child in your family should understand her own origins, and those of her brothers and sisters. But ... children can seem exaggerated because of their different origins. For instance, i f your adoptive child does ...

  12. Travelers' Health: International Adoption

    MedlinePlus

    ... preadoption living standards, varying disease epidemiology in the countries of origin, the presence of previously unidentified medical problems, and ... know the disease risks in the adopted child’s country of origin and the medical and social histories of the ...

  13. Conformational features of secondary N-cyclopropyl amides.

    PubMed

    González-de-Castro, Ángela; Broughton, Howard; Martínez-Pérez, José A; Espinosa, Juan F

    2015-04-17

    NMR studies in conjunction with ab initio calculations revealed unexpected conformational behavior of N-cyclopropylacetamide (1). This secondary amide displays 16-19% E-rotamer (cis) around the carbonyl-nitrogen bond in apolar solvents, in contrast to other aliphatic secondary acetamides in which significant E-rotamer populations are rare due to steric contacts between the substituents on the amide bond. In addition, 1 adopts an ortho conformation around the N-cPr bond instead of the anti conformation generally preferred by secondary acetamides. This distinct conformational behavior was also observed for other secondary N-cyclopropyl amides. PMID:25803271

  14. Conformational properties of bottle-brush polymers

    NASA Astrophysics Data System (ADS)

    Denesyuk, N. A.

    2003-05-01

    General and renormalized perturbation theories are used to study the conformational properties of a bottle-brush molecule, composed of multiarmed polymer stars grafted regularly onto a flexible backbone. The end-to-end distances of the backbone and of an arm of the middle star are calculated within the first order of perturbation theory. For the high grafting densities of stars, the calculated expressions are generalized with the help of the scaling arguments to give the equivalent power laws. According to these laws, the molecule may adopt a sequence of three different conformations (star-rod-coil) as the length of the backbone grows.

  15. Conformational properties of bottle-brush polymers.

    PubMed

    Denesyuk, N A

    2003-05-01

    General and renormalized perturbation theories are used to study the conformational properties of a bottle-brush molecule, composed of multiarmed polymer stars grafted regularly onto a flexible backbone. The end-to-end distances of the backbone and of an arm of the middle star are calculated within the first order of perturbation theory. For the high grafting densities of stars, the calculated expressions are generalized with the help of the scaling arguments to give the equivalent power laws. According to these laws, the molecule may adopt a sequence of three different conformations (star-rod-coil) as the length of the backbone grows. PMID:12786171

  16. 45 CFR 233.110 - Foster care maintenance and adoption assistance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 2 2012-10-01 2012-10-01 false Foster care maintenance and adoption assistance... maintenance and adoption assistance. (a) State plan requirements. A State plan under title IV-A of the Social... Security Act, and operates a foster care maintenance and adoption assistance program in conformity...

  17. 45 CFR 233.110 - Foster care maintenance and adoption assistance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 2 2011-10-01 2011-10-01 false Foster care maintenance and adoption assistance... maintenance and adoption assistance. (a) State plan requirements. A State plan under title IV-A of the Social... Security Act, and operates a foster care maintenance and adoption assistance program in conformity...

  18. 45 CFR 233.110 - Foster care maintenance and adoption assistance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false Foster care maintenance and adoption assistance... maintenance and adoption assistance. (a) State plan requirements. A State plan under title IV-A of the Social... Security Act, and operates a foster care maintenance and adoption assistance program in conformity...

  19. 45 CFR 233.110 - Foster care maintenance and adoption assistance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 2 2014-10-01 2012-10-01 true Foster care maintenance and adoption assistance... maintenance and adoption assistance. (a) State plan requirements. A State plan under title IV-A of the Social... Security Act, and operates a foster care maintenance and adoption assistance program in conformity...

  20. 45 CFR 233.110 - Foster care maintenance and adoption assistance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 2 2013-10-01 2012-10-01 true Foster care maintenance and adoption assistance... maintenance and adoption assistance. (a) State plan requirements. A State plan under title IV-A of the Social... Security Act, and operates a foster care maintenance and adoption assistance program in conformity...

  1. Conformations of Low-Molecular-Weight Lignin Polymers in Water.

    PubMed

    Petridis, Loukas; Smith, Jeremy C

    2016-02-01

    Low-molecular-weight lignin binds to cellulose during the thermochemical pretreatment of biomass for biofuel production, which prevents the efficient hydrolysis of the cellulose to sugars. The binding properties of lignin are influenced strongly by the conformations it adopts. Here, we use molecular dynamics simulations in aqueous solution to investigate the dependence of the shape of lignin polymers on chain length and temperature. Lignin is found to adopt collapsed conformations in water at 300 and 500 K. However, at 300 K, a discontinuous transition is found in the shape of the polymer as a function of the chain length. Below a critical degree of polymerization, Nc =15, the polymer adopts less spherical conformations than above Nc. The transition disappears at high temperatures (500 K) at which only spherical shapes are adopted. An implication relevant to cellulosic biofuel production is that lignin will self-aggregate even at high pretreatment temperatures. PMID:26763657

  2. Galilean conformal electrodynamics

    NASA Astrophysics Data System (ADS)

    Bagchi, Arjun; Basu, Rudranil; Mehra, Aditya

    2014-11-01

    Maxwell's Electrodynamics admits two distinct Galilean limits called the Electric and Magnetic limits. We show that the equations of motion in both these limits are invariant under the Galilean Conformal Algebra in D = 4, thereby exhibiting non-relativistic conformal symmetries. Remarkably, the symmetries are infinite dimensional and thus Galilean Electrodynamics give us the first example of an infinitely extended Galilean Conformal Field Theory in D > 2. We examine details of the theory by looking at purely non-relativistic conformal methods and also use input from the limit of the relativistic theory.

  3. Conformational Isomerism Can Limit Antibody Catalysis

    SciTech Connect

    Debler, E.W.; Muller, R.; Hilvert, D.; Wilson, I.A.

    2009-05-14

    Ligand binding to enzymes and antibodies is often accompanied by protein conformational changes. Although such structural adjustments may be conducive to enzyme catalysis, much less is known about their effect on reactions promoted by engineered catalytic antibodies. Crystallographic and pre-steady state kinetic analyses of antibody 34E4, which efficiently promotes the conversion of benzisoxazoles to salicylonitriles, show that the resting catalyst adopts two interconverting active-site conformations, only one of which is competent to bind substrate. In the predominant isomer, the indole side chain of Trp{sup L91} occupies the binding site and blocks ligand access. Slow conformational isomerization of this residue, on the same time scale as catalytic turnover, creates a deep and narrow binding site that can accommodate substrate and promote proton transfer using Glu{sup H50} as a carboxylate base. Although 34E4 is among the best catalysts for the deprotonation of benzisoxazoles, its efficiency appears to be significantly limited by this conformational plasticity of its active site. Future efforts to improve this antibody might profitably focus on stabilizing the active conformation of the catalyst. Analogous strategies may also be relevant to other engineered proteins that are limited by an unfavorable conformational pre-equilibrium.

  4. Adolescents' Feelings about Openness in Adoption: Implications for Adoption Agencies

    ERIC Educational Resources Information Center

    Berge, Jerica M.; Mendenhall, Tai J.; Wrobel, Gretchen M.; Grotevant, Harold D.; McRoy, Ruth G.

    2006-01-01

    Adoption research commonly uses parents' reports of satisfaction when examining openness in adoption arrangements. This qualitative study aimed to fill a gap in the adoption research by using adolescents' voices to gain a better understanding of their adoption experiences. Adopted adolescents (n = 152) were interviewed concerning their…

  5. Conformal bootstrap in embedding space

    NASA Astrophysics Data System (ADS)

    Fortin, Jean-François; Skiba, Witold

    2016-05-01

    It is shown how to obtain conformal blocks from embedding space with the help of the operator product expansion. The minimal conformal block originates from scalar exchange in a four-point correlation function of four scalars. All remaining conformal blocks are simple derivatives of the minimal conformal block. With the help of the orthogonality properties of the conformal blocks, the analytic conformal bootstrap can be implemented directly in embedding space, leading to a Jacobi-like definition of conformal field theories.

  6. Conformations of Substituted Ethanes.

    ERIC Educational Resources Information Center

    Kingsbury, Charles A.

    1979-01-01

    Reviews state-of-the-art of conformational analysis and factors which affect it. Emphasizes sp-3 hybridized acrylic molecules. Provides examples on the importance of certain factors in determining conformation. Purpose, is to provide examples for examination questions. (Author/SA)

  7. Toddler Adoption: The Weaver's Craft.

    ERIC Educational Resources Information Center

    Hopkins-Best, Mary

    Based on concern about the lack of information on adopting toddlers, this book examines the special needs of adopted toddlers and their adoptive parents. Chapter 1, "Why Write a Book on Toddler Adoption?" details the lack of information on the difficulties of adopted toddlers in forming attachments and parents' child rearing difficulties. Chapter…

  8. CERTS customer adoption model

    SciTech Connect

    Rubio, F. Javier; Siddiqui, Afzal S.; Marnay, Chris; Hamachi,Kristina S.

    2000-03-01

    This effort represents a contribution to the wider distributed energy resources (DER) research of the Consortium for Electric Reliability Technology Solutions (CERTS, http://certs.lbl.gov) that is intended to attack and, hopefully, resolve the technical barriers to DER adoption, particularly those that are unlikely to be of high priority to individual equipment vendors. The longer term goal of the Berkeley Lab effort is to guide the wider technical research towards the key technical problems by forecasting some likely patterns of DER adoption. In sharp contrast to traditional electricity utility planning, this work takes a customer-centric approach and focuses on DER adoption decision making at, what we currently think of as, the customer level. This study reports on Berkeley Lab's second year effort (completed in Federal fiscal year 2000, FY00) of a project aimed to anticipate patterns of customer adoption of distributed energy resources (DER). Marnay, et al., 2000 describes the earlier FY99 Berkeley Lab work. The results presented herein are not intended to represent definitive economic analyses of possible DER projects by any means. The paucity of data available and the importance of excluded factors, such as environmental implications, are simply too important to make such an analysis possible at this time. Rather, the work presented represents a demonstration of the current model and an indicator of the potential to conduct more relevant studies in the future.

  9. Obstacles to Interstate Adoption.

    ERIC Educational Resources Information Center

    Hunt, Roberta

    A documentation of the obstacles in law, policy and administrative procedure that interfere with effecting adoptions across State lines is presented. Major problems include: (1) Nonjudicial termination or relinquishment proceedings, although legal in many States, do not satisfy the courts in other states on the issue of the child's freedom for…

  10. The biological bases of conformity.

    PubMed

    Morgan, T J H; Laland, K N

    2012-01-01

    Humans are characterized by an extreme dependence on culturally transmitted information and recent formal theory predicts that natural selection should favor adaptive learning strategies that facilitate effective copying and decision making. One strategy that has attracted particular attention is conformist transmission, defined as the disproportionately likely adoption of the most common variant. Conformity has historically been emphasized as significant in the social psychology literature, and recently there have also been reports of conformist behavior in non-human animals. However, mathematical analyses differ in how important and widespread they expect conformity to be, and relevant experimental work is scarce, and generates findings that are both mutually contradictory and inconsistent with the predictions of the models. We review the relevant literature considering the causation, function, history, and ontogeny of conformity, and describe a computer-based experiment on human subjects that we carried out in order to resolve ambiguities. We found that only when many demonstrators were available and subjects were uncertain was subject behavior conformist. A further analysis found that the underlying response to social information alone was generally conformist. Thus, our data are consistent with a conformist use of social information, but as subjects' behavior is the result of both social and asocial influences, the resultant behavior may not be conformist. We end by relating these findings to an embryonic cognitive neuroscience literature that has recently begun to explore the neural bases of social learning. Here conformist transmission may be a particularly useful case study, not only because there are well-defined and tractable opportunities to characterize the biological underpinnings of this form of social learning, but also because early findings imply that humans may possess specific cognitive adaptations for effective social learning. PMID:22712006

  11. The Biological Bases of Conformity

    PubMed Central

    Morgan, T. J. H.; Laland, K. N.

    2012-01-01

    Humans are characterized by an extreme dependence on culturally transmitted information and recent formal theory predicts that natural selection should favor adaptive learning strategies that facilitate effective copying and decision making. One strategy that has attracted particular attention is conformist transmission, defined as the disproportionately likely adoption of the most common variant. Conformity has historically been emphasized as significant in the social psychology literature, and recently there have also been reports of conformist behavior in non-human animals. However, mathematical analyses differ in how important and widespread they expect conformity to be, and relevant experimental work is scarce, and generates findings that are both mutually contradictory and inconsistent with the predictions of the models. We review the relevant literature considering the causation, function, history, and ontogeny of conformity, and describe a computer-based experiment on human subjects that we carried out in order to resolve ambiguities. We found that only when many demonstrators were available and subjects were uncertain was subject behavior conformist. A further analysis found that the underlying response to social information alone was generally conformist. Thus, our data are consistent with a conformist use of social information, but as subjects’ behavior is the result of both social and asocial influences, the resultant behavior may not be conformist. We end by relating these findings to an embryonic cognitive neuroscience literature that has recently begun to explore the neural bases of social learning. Here conformist transmission may be a particularly useful case study, not only because there are well-defined and tractable opportunities to characterize the biological underpinnings of this form of social learning, but also because early findings imply that humans may possess specific cognitive adaptations for effective social learning. PMID:22712006

  12. The precaution adoption process.

    PubMed

    Weinstein, N D

    1988-01-01

    This article presents a critique of current models of preventive behavior. It discusses a variety of factors that are usually overlooked-including the appearance of costs and benefits over time, the role of cues to action, the problem of competing life demands, and the ways that actual decision behavior differs from the rational ideal implicit in expectancy-value and utility theories. Such considerations suggest that the adoption of new precautions should be viewed as a dynamic process with many determinants. The framework of a model that is able to accommodate these additional factors is described. This alternative model portrays the precaution adoption process as an orderly sequence of qualitatively different cognitive stages. Data illustrating a few of the suggestions made in the article are presented, and implications for prevention programs are discussed. PMID:3049068

  13. (+/-)-6-tert-butyl-8-hydroxymethyl-2-phenyl-4H-1,3-benzodioxin and 2,2,2',2',6,6'-hexamethyl-8,8'-methylenebis(4H-1,3-benzodioxin).

    PubMed

    Masci, Bernardo; Levi Mortera, Stefano; Varrone, Maurizio; Thuéry, Pierre

    2002-11-01

    Two compounds containing 1,3-benzodioxin groups are reported, namely (+/-)-6-tert-butyl-8-hydroxymethyl-2-phenyl-4H-1,3-benzodioxin, C(19)H(22)O(3), (I), and 2,2,2',2',6,6'-hexamethyl-8,8'-methylenebis(4H-1,3-benzodioxin), C(23)H(28)O(4), (II). The hydroxy groups of neighbouring molecules in (I) are hydrogen bonded to each other, giving rise to double-row chains. The molecule in (II) adopts a 'butterfly' conformation, with the O atoms in distal positions. In both compounds, the dioxin rings are in distorted half-chair conformations. PMID:12415170

  14. Crystal structure of 7-isopropyl-1,4a,N-trimethyl-1,2,3,4,4a,4b,5,6,7,8,10,10a-dodeca-hydro-phenanthrene-1-carb-ox-amide.

    PubMed

    Liu, Li; Yan, Xin-Yan; Rao, Xiao-Ping

    2015-10-01

    In the title compound, C26H37NO, a new derivative of di-hydro-abietic acid, the two cyclo-hexene rings adopt half chair conformations, whereas the cyclo-hexane ring has a chair conformation. Each of the methyl groups is in an axial position with respect to the tricyclic hydro-phenanthrene residue. In the crystal packing, methyl-ene-C-H⋯π(phen-yl) inter-actions lead to supra-molecular helical chains along [010]; the amide-H atom does not form a significant inter-molecular inter-action owing to steric pressure. PMID:26594487

  15. (4R*,4aR*,7aS*)-5-Oxo-6-phenyl-4a,5,6,7,7a,8-hexa-hydro-4H-furo[2,3-f]isoindole-4-carb-oxy-lic acid.

    PubMed

    Horak, Yuriy I; Lytvyn, Roman Z; Zubkov, Fedor I; Nikitina, Eugeniya V; Homza, Yuriy V; Lis, Tadeusz; Kinzhybalo, Vasyl; Obushak, Mykola D

    2013-02-01

    The asymmetric unit of the title compound, C(17)H(15)NO(4), contains two independent mol-ecules with similar geometric parameters. In both mol-ecules, the conformation of the cyclo-hexene ring is half-chair, while the pyrrolidinone ring adopts an envelope conformation with the γ-carbon atom of the α-pyrrolidinone ring as the flap. In the crystal, O-H⋯O hydrogen bonds between the carb-oxylic and carbonyl groups link alternate independent mol-ecules into chains propagating in the b-axis direction. The crystal packing also features weak C-H⋯π inter-actions. PMID:23424547

  16. 19-Benzo-yloxy-13,16-seco-ent-beyeran 13,16-lactone.

    PubMed

    Cai, Jin; Zha, Xiaoming

    2010-01-01

    The title compound, C(27)H(34)O(5), a beyerane-type diterpenoid prepared by peroxidation and benzoyl-ation of isosteviol, contains a fused six-membered ring system. The O atoms of the benzoic ester and the lactone are disordered with occupancy ratios of 0.6 (4):0.4 (4) and 0.6 (2):0.4 (2), respectively. Three cyclo-hexane rings have chair conformations, whereas the remaining lactone ring adopts a half-chair conformation. PMID:21522644

  17. Open Adoption: Adoptive Parents' Reactions Two Decades Later

    ERIC Educational Resources Information Center

    Siegel, Deborah H.

    2013-01-01

    Unlike in the past, most adoption agencies today offer birth parents and adoptive parents the opportunity to share identifying information and have contact with each other. To understand the impacts of different open adoption arrangements, a qualitative descriptive study using a snowball sample of 44 adoptive parents throughout New England began…

  18. Hospitious Adoption: How Hospitality Empowers Children and Transforms Adoption

    ERIC Educational Resources Information Center

    Gritter, James L.

    2009-01-01

    Building on previous books by the author, "Hospitious Adoption: How Hospitality Empowers Children and Transforms Adoption" examines the next step after open adoption. Gritter takes the approach that practicing goodwill, respect, and courage within the realm of adoption makes the process move smoother and enriches children's lives. Following a…

  19. [Conformers of carnosine].

    PubMed

    Kliuev, S A

    2006-01-01

    The geometric and energetic parameters of most stable conformations of carnosine were calculated by the semiempirical guantum-chemical method PM3. The carnosine-water-zinc (II) clusters were simulated. PMID:16909845

  20. Assemblies of Conformal Tanks

    NASA Technical Reports Server (NTRS)

    DeLay, Tom

    2009-01-01

    Assemblies of tanks having shapes that conform to each other and/or conform to other proximate objects have been investigated for use in storing fuels and oxidizers in small available spaces in upper stages of spacecraft. Such assemblies might also prove useful in aircraft, automobiles, boats, and other terrestrial vehicles in which space available for tanks is limited. The basic concept of using conformal tanks to maximize the utilization of limited space is not new in itself: for example, conformal tanks are used in some automobiles to store windshield -washer liquid and coolant that overflows from radiators. The novelty of the present development lies in the concept of an assembly of smaller conformal tanks, as distinguished from a single larger conformal tank. In an assembly of smaller tanks, it would be possible to store different liquids in different tanks. Even if the same liquid were stored in all the tanks, the assembly would offer an advantage by reducing the mechanical disturbance caused by sloshing of fuel in a single larger tank: indeed, the requirement to reduce sloshing is critical in some applications. The figure shows a prototype assembly of conformal tanks. Each tank was fabricated by (1) copper plating a wax tank mandrel to form a liner and (2) wrapping and curing layers of graphite/epoxy composite to form a shell supporting the liner. In this case, the conformal tank surfaces are flat ones where they come in contact with the adjacent tanks. A band of fibers around the outside binds the tanks together tightly in the assembly, which has a quasi-toroidal shape. For proper functioning, it would be necessary to maintain equal pressure in all the tanks.

  1. Quantum massive conformal gravity

    NASA Astrophysics Data System (ADS)

    Faria, F. F.

    2016-04-01

    We first find the linear approximation of the second plus fourth order derivative massive conformal gravity action. Then we reduce the linearized action to separated second order derivative terms, which allows us to quantize the theory by using the standard first order canonical quantization method. It is shown that quantum massive conformal gravity is renormalizable but has ghost states. A possible decoupling of these ghost states at high energies is discussed.

  2. Conformational sampling techniques.

    PubMed

    Hatfield, Marcus P D; Lovas, Sándor

    2014-01-01

    The potential energy hyper-surface of a protein relates the potential energy of the protein to its conformational space. This surface is useful in determining the native conformation of a protein or in examining a statistical-mechanical ensemble of structures (canonical ensemble). In determining the potential energy hyper-surface of a protein three aspects must be considered; reducing the degrees of freedom, a method to determine the energy of each conformation and a method to sample the conformational space. For reducing the degrees of freedom the choice of solvent, coarse graining, constraining degrees of freedom and periodic boundary conditions are discussed. The use of quantum mechanics versus molecular mechanics and the choice of force fields are also discussed, as well as the sampling of the conformational space through deterministic and heuristic approaches. Deterministic methods include knowledge-based statistical methods, rotamer libraries, homology modeling, the build-up method, self-consistent electrostatic field, deformation methods, tree-based elimination and eigenvector following routines. The heuristic methods include Monte Carlo chain growing, energy minimizations, metropolis monte carlo and molecular dynamics. In addition, various methods to enhance the conformational search including the deformation or smoothing of the surface, scaling of system parameters, and multi copy searching are also discussed. PMID:23947647

  3. Adoption Research: Trends, Topics, Outcomes

    ERIC Educational Resources Information Center

    Palacios, Jesus; Brodzinsky, David

    2010-01-01

    The current article provides a review of adoption research since its inception as a field of study. Three historical trends in adoption research are identified: the first focusing on risk in adoption and identifying adoptee-nonadoptee differences in adjustment; the second examining the capacity of adopted children to recover from early adversity;…

  4. The Development of Adoption Law.

    ERIC Educational Resources Information Center

    Bussiere, Alice

    1998-01-01

    Reviews the evolution of U.S. adoption law since 1851. Recounts changes in the perceived "best interests" of all members of the adoption triad over time, and growing recognition of links between adoption and child welfare policy. Discusses current controversies including open adoption, birth parents' rights, unmarried fathers, and the role of…

  5. (1'S,12'R,13'S,17'S)-15',15'-Dimethyl-1,2-dihydro-11',14',16',18'-tetra-oxa-7'-aza-spiro-[indole-3,8'-penta-cyclo-[10.6.0.0(2,9).0(3,7).0(13,17)]octa-deca-ne]-2,10'-dione.

    PubMed

    Sabari, V; Ponnusamy, R; Prasanna, R; Raghunathan, R; Aravindhan, S

    2013-04-01

    In the title compound, C22H24N2O6, the indole ring has a twist conformation and the tetra-hydro-2H-pyran-2-one ring a half-chair conformation. One of the pyrrolidine rings adopts an envelope conformation on the N atom, while the other has a twist conformation; the 'butterfly' angle between their mean planes is 62.98 (11)°. The dioxolane ring adopts a twist conformation and the tetra-hydro-furan ring has an envelope conformation on the C atom in the fused tetra-hydro-2H-pyran-2-one ring adjacent to the O atom of the tetra-hydro-furan ring. The 'butterfly' angle between the mean planes of these two five-membered rings is 69.14 (10)°. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds, forming chains along the a axis. PMID:23634025

  6. Becoming Lesbian Adoptive Parents: An Exploratory Study of Lesbian Adoptive, Lesbian Birth, and Heterosexual Adoptive Parents.

    ERIC Educational Resources Information Center

    Shelley-Sireci, Lynn M.; Ciano-Boyce, Claudia

    2002-01-01

    Surveyed lesbian adoptive parents, heterosexual adoptive parents, and lesbian parents who had used assisted fertilization, regarding the adoption process. Found that the process was similar for both heterosexual and lesbian parents, but lesbian adoptive parents perceived more discrimination and were more inclined to omit information during the…

  7. EHR adopters vs. non-adopters: Impacts of, barriers to, and federal initiatives for EHR adoption

    PubMed Central

    Jamoom, Eric W.; Patel, Vaishali; Furukawa, Michael F.; King, Jennifer

    2016-01-01

    While adoption of electronic health record (EHR) systems has grown rapidly, little is known about physicians’ perspectives on its adoption and use. Nationally representative survey data from 2011 are used to compare the perspectives of physicians who have adopted EHRs with those that have yet to do so across three key areas: the impact of EHRs on clinical care, practice efficiency and operations; barriers to EHR adoption; and factors that influence physicians to adopt EHRs. Despite significant differences in perspectives between adopters and non-adopters, the majority of physicians perceive that EHR use yields overall clinical benefits, more efficient practices and financial benefits. Purchase cost and productivity loss are the greatest barriers to EHR adoption among both adopters and non-adopters; although non-adopters have significantly higher rates of reporting these as barriers. Financial incentives and penalties, technical assistance, and the capability for electronic health information exchange are factors with the greatest influence on EHR adoption among all physicians. However, a substantially higher proportion of non-adopters regard various national health IT policies, and in particular, financial incentives or penalties as a major influence in their decision to adopt an EHR system. Contrasting these perspectives provides a window into how national policies have shaped adoption thus far; and how these policies may shape adoption in the near future. PMID:26250087

  8. Conformal Collineations in String Cosmology

    NASA Astrophysics Data System (ADS)

    Baysal, Hüsnü; Camci, U.ğur; Tarhan, İsmail; Yilmaz, İhsan; Yavuz, İlhami; Dolgov, A.

    In this paper, we study the consequences of the existence of conformal collineations (CC) for string cloud in the context of general relativity. Especially, we interest in special conformal collineation (SCC), generated by a special affine conformal collineation (SACC) in the string cloud. Some results on the restrictions imposed by a conformal collineation symmetry in the string cloud are obtained.

  9. Conformational kinetics reveals affinities of protein conformational states

    PubMed Central

    Daniels, Kyle G.; Suo, Yang; Oas, Terrence G.

    2015-01-01

    Most biological reactions rely on interplay between binding and changes in both macromolecular structure and dynamics. Practical understanding of this interplay requires detection of critical intermediates and determination of their binding and conformational characteristics. However, many of these species are only transiently present and they have often been overlooked in mechanistic studies of reactions that couple binding to conformational change. We monitored the kinetics of ligand-induced conformational changes in a small protein using six different ligands. We analyzed the kinetic data to simultaneously determine both binding affinities for the conformational states and the rate constants of conformational change. The approach we used is sufficiently robust to determine the affinities of three conformational states and detect even modest differences in the protein’s affinities for relatively similar ligands. Ligand binding favors higher-affinity conformational states by increasing forward conformational rate constants and/or decreasing reverse conformational rate constants. The amounts by which forward rate constants increase and reverse rate constants decrease are proportional to the ratio of affinities of the conformational states. We also show that both the affinity ratio and another parameter, which quantifies the changes in conformational rate constants upon ligand binding, are strong determinants of the mechanism (conformational selection and/or induced fit) of molecular recognition. Our results highlight the utility of analyzing the kinetics of conformational changes to determine affinities that cannot be determined from equilibrium experiments. Most importantly, they demonstrate an inextricable link between conformational dynamics and the binding affinities of conformational states. PMID:26162682

  10. Special topics in international adoption.

    PubMed

    Jenista, Jerri Ann

    2005-10-01

    As international adoption has become more "mainstream," the issues recently addressed in domestic adoption have become more important in adoptions involving children originating in other countries. Certain groups of prospective adoptive parents, such as gay or lesbian couples, single parents, and parents with disabilities, have begun to apply to adopt in ever increasing numbers. Children who may have been considered unadoptable in the past are now routinely being offered to prospective adoptive parents. The numbers and ages of the children placed and the spacing between adoptions have come under scrutiny. The rates of adoption dissolutions and disruptions are being examined carefully by the receiving and sending countries. There is a pressing need for research into numerous social aspects of adoption. PMID:16154473

  11. Conformational flexibility of mephenesin.

    PubMed

    Écija, Patricia; Evangelisti, Luca; Vallejo, Montserrat; Basterretxea, Francisco J; Lesarri, Alberto; Castaño, Fernando; Caminati, Walther; Cocinero, Emilio J

    2014-05-22

    The mephenesin molecule (3-(2-methylphenoxy)propane-1,2-diol) serves as a test bank to explore several structural and dynamical issues, such as conformational flexibility, the orientation of the carbon linear chain relative to the benzene plane, or the effect of substituent position on the rotational barrier of a methyl group. The molecule has been studied by rotational spectroscopy in the 4-18 GHz frequency range by Fourier-transform methods in a supersonic expansion. The experiment has been backed by a previous conformational search plus optimization of the lowest energy structures by ab initio and density functional quantum calculations. The three lowest-lying conformers that can interconvert to each other by simple bond rotations have been detected in the jet. Rotational parameters for all structures have been obtained, and methyl torsional barriers have been determined for the two lowest-lying rotamers. The lowest-lying structure of mephenesin is highly planar, with all carbon atoms lying nearly in the benzene ring plane, and is stabilized by the formation of cooperative intramolecular hydrogen bonding. An estimation of the relative abundance of the detected conformers indicates that the energetically most stable conformer will have an abundance near 80% at temperatures relevant for biological activity. PMID:24754523

  12. Conformers of Gaseous Serine.

    PubMed

    He, Kedan; Allen, Wesley D

    2016-08-01

    The myriad conformers of the neutral form of natural amino acid serine (Ser) have been investigated by systematic computations with reliable electronic wave function methods. A total of 85 unique conformers were located using the MP2/cc-pVTZ level of theory. The 12 lowest-energy conformers of serine fall within a 8 kJ mol(-1) window, and for these species, geometric structures, precise relative energies, equilibrium and vibrationally averaged rotational constants, anharmonic vibrational frequencies, infrared intensities, quartic and sextic centrifugal distortion constants, dipole moments, and (14)N nuclear quadrupole coupling constants were computed. The relative energies were refined through composite focal-point analyses employing basis sets as large as aug-cc-pV5Z and correlation treatments through CCSD(T). The rotational constants for seven conformers measured by Fourier-transform microwave spectroscopy are in good agreement with the vibrationally averaged rotational constants computed in this study. Our anharmonic vibrational frequencies are compared to the large number of experimental vibrational absorptions attributable to at least six conformers. PMID:27294314

  13. The emotional aftermath of adoption.

    PubMed

    Nadelson, C C

    1976-09-01

    Adopted children are emotionally vulnerable. Adoptive parents must cope with more complex problems than biologic parents. The family physician can provide valuable counseling. Preadoption counseling focuses on motivation and ambivalence. After adoption, however, serious, sometimes predictable, issues arise, such as: how and when to tell the child he is adopted; the child's search for knowledge; the problem of subsequent divorce; the birth of a natural sibling, and the involvement of other family members. New concepts include "open adoption" and "single parent adoption." PMID:961560

  14. Raman spectra and conformations of dibenzo- and dicyclohexano-18-crown-6

    NASA Astrophysics Data System (ADS)

    Takeuchi, Hideo; Arai, Takaki; Harada, Issei

    1990-06-01

    Conformations of dibenzo-18-crown-6 (DBC), dicyclohexano-18-crown-6 (DCC) and their alkali cation complexes in the solid state and in solution have been investigated by Raman spectroscopy. The Raman spectra were analysed by using the relationships between Raman frequencies and conformations previously found for unsubstituted crown ethers. DBC takes a conformation, ( tCttGttG't) 2, with gauche ( G) or gauche' ( G') 2CH 2 bonds, trans ( t) CO bonds and cis ( C) OCCO linkages at the benzene rings, when it complexes with a cation in the solid state and in solution. Uncomplexed DBC adopts another conformation in the solid state, which contains both the trans and gauche conformations about the CH 2CH 2 and CO bonds. In solution, uncomplexed DBC exists as a mixture of conformers including the two conformers described above. Vibrational couplings between the oxyethylene and cyclohexane rings are strong in DCC and its strength depends on the crown conformation. The cation-bound crown rings of DCC isomers A and B in solution predominantly take the same conformation, ( tG'ttGt) 3, found for the crystalline isomer B-NaBr complex. A metastable conformer containing trans CH 2CH 2 bonding is found for the Na + complexes of both isomers in solution. Uncomplexed DCC adopts different crown ring conformations in isomers A and B in the solid state and diverse conformational states in solution.

  15. Adoptions Without Agencies: A Study of Independent Adoptions.

    ERIC Educational Resources Information Center

    Meezan, William; And Others

    The purposes of this national study of independent, nonagency adoptions were: (1) to determine the experience of the parties involved (biological parents, adoptive parents, agencies, intermediaries, and law enforcement agents); (2) to identify agency policies, procedures and resources that deter agency adoptions and thus encourage independent…

  16. Parents' Feelings towards Their Adoptive and Non-Adoptive Children

    ERIC Educational Resources Information Center

    Glover, Marshaun B.; Mullineaux, Paula Y.; Deater-Deckard, Kirby; Petrill, Stephen A.

    2010-01-01

    In the current study, we examined parent gender differences in feelings (negativity and positivity) and perceptions of child behavioural and emotional problems in adoptive and biological parent-child dyads. In a sample of 85 families, we used a novel within-family adoption design in which one child was adopted and one child was a biological child…

  17. Extended conformal algebras

    NASA Astrophysics Data System (ADS)

    Bouwknegt, Peter

    1988-06-01

    We investigate extensions of the Virasoro algebra by a single primary field of integer or halfinteger conformal dimension Δ. We argue that for vanishing structure constant CΔΔΔ, the extended conformal algebra can only be associative for a generic c-value if Δ=1/2, 1, 3/2, 2 or 3. For the other Δ<=5 we compute the finite set of allowed c-values and identify the rational solutions. The case CΔΔΔ≠0 is also briefly discussed. I would like to thank Kareljan Schoutens for discussions and Sander Bais for a careful reading of the manuscript.

  18. Charged conformal Killing spinors

    SciTech Connect

    Lischewski, Andree

    2015-01-15

    We study the twistor equation on pseudo-Riemannian Spin{sup c}-manifolds whose solutions we call charged conformal Killing spinors (CCKSs). We derive several integrability conditions for the existence of CCKS and study their relations to spinor bilinears. A construction principle for Lorentzian manifolds admitting CCKS with nontrivial charge starting from CR-geometry is presented. We obtain a partial classification result in the Lorentzian case under the additional assumption that the associated Dirac current is normal conformal and complete the classification of manifolds admitting CCKS in all dimensions and signatures ≤5 which has recently been initiated in the study of supersymmetric field theories on curved space.

  19. A Phenomenological Exploration of Adoption

    ERIC Educational Resources Information Center

    Baltimore, Diana L.; Crase, Sedahlia Jasper

    2009-01-01

    This qualitative analysis explored children's and adults' experiences with adoption. We used phenomenological methodology and individually interviewed 25 participants and included adoptive mothers and fathers, and their children, each adopted before 18 months of age. Two research questions guided the data analysis: (a) What are children's and…

  20. Dogmatism and Attitudes Toward Adoption

    ERIC Educational Resources Information Center

    Dembroski, Betty G.; Johnson Dale L.

    1969-01-01

    Using Rokeach's Dogmatism Scale and an Adoption Attitude Scale administered to 113 college students study supports hypothesis that among males dogmatism and intolerance toward areas relating to adoption would be positively correlated. Negative correlation for females suggests that emphasis on maternal role makes adoption attitudes exception to…

  1. Adoption Resources for Black Children

    ERIC Educational Resources Information Center

    Gallagher, Ursula M.

    1971-01-01

    The growing number of adoptions in this country, including racially mixed adoptions, attest to the general acceptance of adoption as a way of bringing love to children in need of families of their own and the satisfactions of parenthood to childless couples, single men and women, and families who have room for one more. (Author/AJ)

  2. Conformation Dependence of Backbone Geometry in Proteins

    PubMed Central

    Berkholz, Donald S.; Shapovalov, Maxim V.; Dunbrack, Roland L.; Karplus, P. Andrew

    2009-01-01

    Summary Protein structure determination and predictive modeling have long been guided by the paradigm that the peptide backbone has a single, context-independent ideal geometry. Both quantum-mechanics calculations and empirical analyses have shown this is an incorrect simplification in that backbone covalent geometry actually varies systematically as a function of the Φ and Ψ backbone dihedral angles. Here, we use a nonredundant set of ultrahigh-resolution protein structures to define these conformation-dependent variations. The trends have a rational, structural basis that can be explained by avoidance of atomic clashes or optimization of favorable electrostatic interactions. To facilitate adoption of this new paradigm, we have created a conformation-dependent library of covalent bond lengths and bond angles and shown that it has improved accuracy over existing methods without any additional variables to optimize. Protein structures derived both from crystallographic refinement and predictive modeling both stand to benefit from incorporation of the new paradigm. PMID:19836332

  3. Conformal cloak for waves

    SciTech Connect

    Chen Huanyang; Leonhardt, Ulf; Tyc, Tomas

    2011-05-15

    Conformal invisibility devices are only supposed to work within the valid range of geometrical optics. Here, we show by numerical simulations and analytical arguments that for certain quantized frequencies, they are nearly perfect even in a regime that clearly violates geometrical optics. The quantization condition follows from the analogy between the Helmholtz equation and the stationary Schroedinger equation.

  4. Extended conformal field theories

    NASA Astrophysics Data System (ADS)

    Taormina, Anne

    1990-08-01

    Some extended conformal field theories are briefly reviewed. They illustrate how non minimal models of the Virasoro algebra (c≥1) can become minimal with respect to a larger algebra. The accent is put on N-extended superconformal algebras, which are relevant in superstring compactification.

  5. PERSONALITY AND CONFORMITY.

    ERIC Educational Resources Information Center

    BAROCAS, RALPH; GORLOW, LEON

    AN INVESTIGATION WAS MADE OF THE RELATIONSHIP BETWEEN PERSONALITY FACTORS AND CONFORMITY. THE SUBJECTS WERE 243 RANDOMLY SELECTED STUDENTS ENROLLED IN COLLEGE PSYCHOLOGY COURSES WHO WERE DIVIDED INTO GROUPS OF 97, 96, AND 50 SUBJECTS. A PERSONALITY FACTOR INVENTORY WAS OBTAINED FROM RESPONSES TO A LARGE LIST OF TRUE-FALSE PERSONALITY ITEM…

  6. Animal culture: chimpanzee conformity?

    PubMed

    van Schaik, Carel P

    2012-05-22

    Culture-like phenomena in wild animals have received much attention, but how good is the evidence and how similar are they to human culture? New data on chimpanzees suggest their culture may even have an element of conformity. PMID:22625856

  7. Conformational changes in biopolymers

    NASA Astrophysics Data System (ADS)

    Ivanov, Vassili

    2005-12-01

    Biopolymer conformational changes are involved in many biological processes. This thesis summarizes some theoretical and experimental approaches which I have taken at UCLA to explore conformational changes in biopolymers. The reversible thermal denaturation of the DNA double helix is, perhaps, the simplest example of biopolymer conformational change. I have developed a statistical mechanics model of DNA melting with reduced degrees of freedom, which allows base stacking interaction to be taken into account and treat base pairing and stacking separately. Unlike previous models, this model describes both the unpairing and unstacking parts of the experimental melting curves and explains the observed temperature dependence of the effective thermodynamic parameters used in models of the nearest neighbor type. I developed a basic kinetic model for irreversible thermal denaturation of F-actin, which incorporates depolymerization of F-actin from the ends and breaking of F-actin fiber in the middle. The model explains the cooperativity of F-actin thermal denaturation observed by D. Pavlov et al. in differential calorimetry measurements. CG-rich DNA sequences form left-handed Z-DNA at high ionic strength or upon binding of polyvalent ions and some proteins. I studied experimentally the B-to-Z transition of the (CG)6 dodecamer. Improvement of the locally linearized model used to interpret the data gives evidence for an intermediate state in the B-to-Z transition of DNA, contrary to previous research on this subject. In the past 15 years it has become possible to study the conformational changes of biomolecules using single-molecule techniques. In collaboration with other lab members I performed a single-molecule experiment, where we monitored the displacement of a micrometer-size bead tethered to a surface by a DNA probe undergoing the conformational change. This technique allows probing of conformational changes with subnanometer accuracy. We applied the method to detect

  8. Galilean conformal and superconformal symmetries

    SciTech Connect

    Lukierski, J.

    2012-10-15

    Firstly we discuss briefly three different algebras named as nonrelativistic (NR) conformal: Schroedinger, Galilean conformal, and infinite algebra of local NR conformal isometries. Further we shall consider in some detail Galilean conformal algebra (GCA) obtained in the limit c{yields}{infinity} from relativistic conformal algebraO(d+1, 2) (d-number of space dimensions). Two different contraction limits providing GCA and some recently considered realizations will be briefly discussed. Finally by considering NR contraction of D = 4 superconformal algebra the Galilei conformal superalgebra (GCSA) is obtained, in the formulation using complexWeyl supercharges.

  9. 18 CFR 415.51 - Prior non-conforming structures.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... structures. 415.51 Section 415.51 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION... structures. A structure which was lawful before the adoption of this regulation but which is not in... this part): (a) A non-conforming structure in the floodway may not be expanded, except that it may...

  10. Technology Adoption: an Interaction Perspective

    NASA Astrophysics Data System (ADS)

    Sitorus, Hotna M.; Govindaraju, Rajesri; Wiratmadja, I. I.; Sudirman, Iman

    2016-02-01

    The success of a new technology depends on how well it is accepted by its intended users. Many technologies face the problem of low adoption rate, despite the benefits. An understanding of what makes people accept or reject a new technology can help speed up the adoption rate. This paper presents a framework for technology adoption based on an interactive perspective, resulting from a literature study on technology adoption. In studying technology adoption, it is necessary to consider the interactions among elements involved in the system, for these interactions may generate new characteristics or new relationships. The interactions among elements in a system adoption have not received sufficient consideration in previous studies of technology adoption. Based on the proposed interaction perspective, technology adoption is elaborated by examining interactions among the individual (i.e. the user or prospective user), the technology, the task and the environment. The framework is formulated by adopting several theories, including Perceived Characteristics of Innovating, Diffusion of Innovation Theory, Technology Acceptance Model, Task-Technology Fit and usability theory. The proposed framework is illustrated in the context of mobile banking adoption. It is aimed to offer a better understanding of determinants of technology adoption in various contexts, including technology in manufacturing systems.

  11. Movement of Elongation Factor G between Compact and Extended Conformations

    PubMed Central

    Salsi, Enea; Farah, Elie; Netter, Zoe; Dann, Jillian; Ermolenko, Dmitri N.

    2014-01-01

    Previous structural studies suggested that ribosomal translocation is accompanied by large interdomain rearrangements of elongation factor G (EF-G). Here, we follow the movement of domain IV of EF-G relative to domain II of EF-G using ensemble and single-molecule Förster resonance energy transfer (smFRET). Our results indicate that ribosome-free EF-G predominantly adopts a compact conformation that can also, albeit infrequently, transition into a more extended conformation in which domain IV moves away from domain II. By contrast, ribosome-bound EF-G predominantly adopts an extended conformation regardless of whether it is interacting with pre- or posttranslocation ribosomes. Our data suggest that ribosome-bound EF-G may also occasionally sample at least one more compact conformation. GTP hydrolysis catalyzed by EF-G does not affect the relative stability of the observed conformations in ribosome-free and ribosome-bound EF-G. Our data support a model suggesting that, upon binding to a pretranslocation ribosome, EF-G moves from a compact to a more extended conformation. This transition is not coupled to, but likely precedes both GTP hydrolysis and mRNA/tRNA translocation. PMID:25463439

  12. Intercountry versus Transracial Adoption: Analysis of Adoptive Parents' Motivations and Preferences in Adoption

    ERIC Educational Resources Information Center

    Zhang, Yuanting; Lee, Gary R.

    2011-01-01

    The United States is one of the major baby-receiving countries in the world. Relatively little research has focused on why there is such a high demand for intercountry adoption. Using in-depth qualitative interviews with adoptive parents, the authors explored the reasons why Americans prefer to adopt foreign-born children instead of adopting…

  13. Multiscale conformal pattern transfer

    PubMed Central

    Lodewijks, Kristof; Miljkovic, Vladimir; Massiot, Inès; Mekonnen, Addis; Verre, Ruggero; Olsson, Eva; Dmitriev, Alexandre

    2016-01-01

    We demonstrate a method for seamless transfer from a parent flat substrate of basically any lithographic top-down or bottom-up pattern onto essentially any kind of surface. The nano- or microscale patterns, spanning macroscopic surface areas, can be transferred with high conformity onto a large variety of surfaces when such patterns are produced on a thin carbon film, grown on top of a sacrificial layer. The latter allows lifting the patterns from the flat parent substrate onto a water-air interface to be picked up by the host surface of choice. We illustrate the power of this technique by functionalizing broad range of materials including glass, plastics, metals, rough semiconductors and polymers, highlighting the potential applications in in situ colorimetry of the chemistry of materials, anti-counterfeit technologies, biomolecular and biomedical studies, light-matter interactions at the nanoscale, conformal photovoltaics and flexible electronics. PMID:27329824

  14. Multiscale conformal pattern transfer

    NASA Astrophysics Data System (ADS)

    Lodewijks, Kristof; Miljkovic, Vladimir; Massiot, Inès; Mekonnen, Addis; Verre, Ruggero; Olsson, Eva; Dmitriev, Alexandre

    2016-06-01

    We demonstrate a method for seamless transfer from a parent flat substrate of basically any lithographic top-down or bottom-up pattern onto essentially any kind of surface. The nano- or microscale patterns, spanning macroscopic surface areas, can be transferred with high conformity onto a large variety of surfaces when such patterns are produced on a thin carbon film, grown on top of a sacrificial layer. The latter allows lifting the patterns from the flat parent substrate onto a water-air interface to be picked up by the host surface of choice. We illustrate the power of this technique by functionalizing broad range of materials including glass, plastics, metals, rough semiconductors and polymers, highlighting the potential applications in in situ colorimetry of the chemistry of materials, anti-counterfeit technologies, biomolecular and biomedical studies, light-matter interactions at the nanoscale, conformal photovoltaics and flexible electronics.

  15. Multiscale conformal pattern transfer.

    PubMed

    Lodewijks, Kristof; Miljkovic, Vladimir; Massiot, Inès; Mekonnen, Addis; Verre, Ruggero; Olsson, Eva; Dmitriev, Alexandre

    2016-01-01

    We demonstrate a method for seamless transfer from a parent flat substrate of basically any lithographic top-down or bottom-up pattern onto essentially any kind of surface. The nano- or microscale patterns, spanning macroscopic surface areas, can be transferred with high conformity onto a large variety of surfaces when such patterns are produced on a thin carbon film, grown on top of a sacrificial layer. The latter allows lifting the patterns from the flat parent substrate onto a water-air interface to be picked up by the host surface of choice. We illustrate the power of this technique by functionalizing broad range of materials including glass, plastics, metals, rough semiconductors and polymers, highlighting the potential applications in in situ colorimetry of the chemistry of materials, anti-counterfeit technologies, biomolecular and biomedical studies, light-matter interactions at the nanoscale, conformal photovoltaics and flexible electronics. PMID:27329824

  16. Conformal gripping device

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2009-01-01

    The present invention relates to a conformal gripping device. In an embodiment of the present invention a conformal gripper device may be disclosed comprising a frame that includes an array of movable pins. The device may also include a roller locking and unlocking system within the frame. The system may comprise a pair of locking rollers for each row of gripper pins to facilitate locking and unlocking the array of gripper pins on a column-by-column basis. The system may also include a striker element that may force the locking rollers to roll along an angled roll surface to facilitate unlocking of the array of pins on a column-by-column basis. The system may further include an electromagnetic actuator or solenoid and permanent magnets to facilitate movement of the striker element and the locking rollers.

  17. Conformational flexibility of aspartame.

    PubMed

    Toniolo, Claudio; Temussi, Pierandrea

    2016-05-01

    L-Aspartyl-L-phenylalanine methyl ester, better known as aspartame, is not only one of the most used artificial sweeteners, but also a very interesting molecule with respect to the correlation between molecular structure and taste. The extreme conformational flexibility of this dipeptide posed a huge difficulty when researchers tried to use it as a lead compound to design new sweeteners. In particular, it was difficult to take advantage of its molecular model as a mold to infer the shape of the, then unknown, active site of the sweet taste receptor. Here, we follow the story of the 3D structural aspects of aspartame from early conformational studies to recent docking into homology models of the receptor. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 376-384, 2016. PMID:27038223

  18. The conformal bootstrap

    NASA Astrophysics Data System (ADS)

    Poland, David; Simmons-Duffin, David

    2016-06-01

    The conformal bootstrap was proposed in the 1970s as a strategy for calculating the properties of second-order phase transitions. After spectacular success elucidating two-dimensional systems, little progress was made on systems in higher dimensions until a recent renaissance beginning in 2008. We report on some of the main results and ideas from this renaissance, focusing on new determinations of critical exponents and correlation functions in the three-dimensional Ising and O(N) models.

  19. Conformal scalar field wormholes

    NASA Technical Reports Server (NTRS)

    Halliwell, Jonathan J.; Laflamme, Raymond

    1989-01-01

    The Euclidian Einstein equations with a cosmological constant and a conformally coupled scalar field are solved, taking the metric to be of the Robertson-Walker type. In the case Lambda = 0, solutions are found which represent a wormhole connecting two asymptotically flat Euclidian regions. In the case Lambda greater than 0, the solutions represent tunneling from a small Tolman-like universe to a large Robertson-Walker universe.

  20. Conformations of organophosphine oxides

    DOE PAGESBeta

    De Silva, Nuwan; Zahariev, Federico; Hay, Benjamin P.; Gordon, Mark S.; Windus, Theresa L.

    2015-07-17

    The conformations of a series of organophosphine oxides, OP(CH3)2R, where R = methyl, ethyl, isopropyl, tert-butyl, vinyl, and phenyl, are predicted using the MP2/cc-pVTZ level of theory. Comparison of potential energy surfaces for rotation about P–C bonds with crystal structure data reveals a strong correlation between predicted location and energetics of minima and histograms of dihedral angle distributions observed in the solid state. In addition, the most stable conformers are those that minimize the extent of steric repulsion between adjacent rotor substituents, and the torsional barriers tend to increase with the steric bulk of the rotating alkyl group. MM3 forcemore » field parameters were adjusted to fit the MP2 results, providing a fast and accurate model for predicting organophosphine oxides shapes—an essential part of understanding the chemistry of these compounds. As a result, the predictive power of the modified MM3 model was tested against MP2/cc-pVTZ conformations for triethylphosphine oxide, OP(CH2CH3)3, and triphenylphosphine oxide, OP(Ph)3.« less

  1. Conformations of organophosphine oxides

    SciTech Connect

    De Silva, Nuwan; Zahariev, Federico; Hay, Benjamin P.; Gordon, Mark S.; Windus, Theresa L.

    2015-07-17

    The conformations of a series of organophosphine oxides, OP(CH3)2R, where R = methyl, ethyl, isopropyl, tert-butyl, vinyl, and phenyl, are predicted using the MP2/cc-pVTZ level of theory. Comparison of potential energy surfaces for rotation about P–C bonds with crystal structure data reveals a strong correlation between predicted location and energetics of minima and histograms of dihedral angle distributions observed in the solid state. In addition, the most stable conformers are those that minimize the extent of steric repulsion between adjacent rotor substituents, and the torsional barriers tend to increase with the steric bulk of the rotating alkyl group. MM3 force field parameters were adjusted to fit the MP2 results, providing a fast and accurate model for predicting organophosphine oxides shapes—an essential part of understanding the chemistry of these compounds. As a result, the predictive power of the modified MM3 model was tested against MP2/cc-pVTZ conformations for triethylphosphine oxide, OP(CH2CH3)3, and triphenylphosphine oxide, OP(Ph)3.

  2. Hot conformal gauge theories

    NASA Astrophysics Data System (ADS)

    Mojaza, Matin; Pica, Claudio; Sannino, Francesco

    2010-12-01

    We compute the nonzero temperature free energy up to the order g6ln⁡(1/g) in the coupling constant for vectorlike SU(N) gauge theories featuring matter transforming according to different representations of the underlying gauge group. The number of matter fields, i.e. flavors, is arranged in such a way that the theory develops a perturbative stable infrared fixed point at zero temperature. Because of large distance conformality we trade the coupling constant with its fixed point value and define a reduced free energy which depends only on the number of flavors, colors, and matter representation. We show that the reduced free energy changes sign, at the second, fifth, and sixth order in the coupling, when decreasing the number of flavors from the upper end of the conformal window. If the change in sign is interpreted as a signal of an instability of the system then we infer a critical number of flavors. Surprisingly this number, if computed to the order g2, agrees with previous predictions for the lower boundary of the conformal window for nonsupersymmetric gauge theories. The higher order results tend to predict a higher number of critical flavors. These are universal properties, i.e. they are independent of the specific matter representation.

  3. Dissecting conformational contributions to glycosidase catalysis and inhibition

    PubMed Central

    Speciale, Gaetano; Thompson, Andrew J; Davies, Gideon J; Williams, Spencer J

    2014-01-01

    Glycoside hydrolases (GHs) are classified into >100 sequence-based families. These enzymes process a wide variety of complex carbohydrates with varying stereochemistry at the anomeric and other ring positions. The shapes that these sugars adopt upon binding to their cognate GHs, and the conformational changes that occur along the catalysis reaction coordinate is termed the conformational itinerary. Efforts to define the conformational itineraries of GHs have focussed upon the critical points of the reaction: substrate-bound (Michaelis), transition state, intermediate (if relevant) and product-bound. Recent approaches to defining conformational itineraries that marry X-ray crystallography of enzymes bound to ligands that mimic the critical points, along with advanced computational methods and kinetic isotope effects are discussed. PMID:25016573

  4. Openness in Adoption: Research with the Adoption Kinship Network.

    ERIC Educational Resources Information Center

    Grotevant, Harold D.

    2000-01-01

    Summarizes current research on the outcomes of open adoption. Discusses issues involved in conducting research on openness and offers methodological recommendations. Provides examples from one research program with adoptive kinship networks. Concludes that psychological outcomes were less related to the level of openness than to the dynamics of…

  5. Adoption and Assisted Reproduction. Adoption and Ethics, Volume 4.

    ERIC Educational Resources Information Center

    Freundlich, Madelyn

    The controversies in adoption have extended across a spectrum of policy and practice issues, and although the issues have become clear, resolution has not been achieved nor has consensus developed regarding a framework on which to improve the quality of adoption policy and practice. This book is the fourth in a series to use an ethics-based…

  6. Homosexuality and adoption in Brazil.

    PubMed

    Uziel, A P

    2001-11-01

    Western societies are undergoing legal and policy changes in relation to laws governing the family, marital status, sexual orientation and the welfare of children, including in Brazil where, in the 1990s, the rights of homosexuals were incorporated into ongoing debates about what constitutes a family. This paper discusses the issue of adoption of children by homosexual men in Brazil, using information from court records from 1995-2000 in Rio de Janeiro, and from interviews with two judges, five psychologists and four social workers who evaluate those wishing to adopt. It uses the case records of one man's application to adopt, in which homosexuality became a central issue. Both the construction of masculinity in relation to parenting and concepts of the family were the parameters upon which the decision to allow him to adopt or not depended. Because the legislation does not specify what the sexual orientation of would-be adoptive parents should be, it is possible for single persons to adopt if they show they can be good parents. As more single people, alone or in couples, seek to adopt, it is important to clarify the criteria for judicial decisions on adoption applications. A dialogue is therefore needed on the meaning of family and whether and how it relates to sexual orientation. It is only on this basis that the courts can take a clear decision as to whether being homosexual is a relevant issue in regard to applications to adopt or not. PMID:11765396

  7. Crystal structure of 1-benzyl-sulfonyl-1,2,3,4-tetra-hydro-quinoline.

    PubMed

    Jeyaseelan, S; Sowmya, B R; Venkateshappa, G; Raghavendra Kumar, P; Palakshamurthy, B S

    2015-04-01

    In the title compound, C16H17NO2S, the heterocyclic ring adopts a half-chair conformation and the bond-angle sum at the N atom is 354.6°. The dihedral angle between the planes of the aromatic rings is 74.15 (10)°. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds, generating C(8) and C(4) chains propagating along [100] and [010], respectively, which together generate (001) sheets. PMID:26029439

  8. Crystal structure of 1-benzyl­sulfonyl-1,2,3,4-tetra­hydro­quinoline

    PubMed Central

    Jeyaseelan, S.; Sowmya, B. R.; Venkateshappa, G.; Raghavendra Kumar, P.; Palakshamurthy, B. S.

    2015-01-01

    In the title compound, C16H17NO2S, the heterocyclic ring adopts a half-chair conformation and the bond-angle sum at the N atom is 354.6°. The dihedral angle between the planes of the aromatic rings is 74.15 (10)°. In the crystal, mol­ecules are linked by weak C—H⋯O hydrogen bonds, generating C(8) and C(4) chains propagating along [100] and [010], respectively, which together generate (001) sheets. PMID:26029439

  9. 3-Hy­droxy-2-[(2E)-1-(2-hy­droxy-6-oxocyclo­hex-1-en-1-yl)-3-(2-meth­oxy­phen­yl)prop-2-en-1-yl]cyclo­hex-2-en-1-one

    PubMed Central

    Cha, Joo Hwan; Son, Myung Hee; Min, Sun-Joon; Cho, Yong Seo; Lee, Jae Kyun

    2011-01-01

    In the title compound, C22H24O5, each of the cyclo­hexenone rings adopts a half-chair conformation. The hy­droxy and carbonyl O atoms face each other and are orientated to allow for the formation of the two intra­molecular O—H⋯O hydrogen bonds which are typical of xanthene derivatives. In the crystal, weak inter­molecular C—H⋯O hydrogen bonds link mol­ecules into layers parallel to the ab plane. PMID:22065620

  10. N-(3,4-Dimethyl-phen-yl)-4-hydr-oxy-2-methyl-2H-1,2-benzothia-zine-3-carboxamide 1,1-dioxide.

    PubMed

    Siddiqui, Waseeq Ahmad; Ali, Muhammad; Zia-Ur-Rehman, Muhammad; Sharif, Saima; Tizzard, Graham John

    2009-01-01

    1,2-Benzothia-zines similar to the title compound, C(18)H(18)N(2)O(4)S, are well known in the literature for their biological activities and are used as medicines in the treatment of inflammation and rheumatoid arthritis. The thia-zine ring adopts a distorted half-chair conformation. The enolic H atom is involved in an intra-molecular O-H⋯O hydrogen bond, forming a six-membered ring. In the crystal, mol-ecules arrange themselves into centrosymmetric dimers by means of pairs of weak inter-molecular N-H⋯O hydrogen bonds. PMID:21582605

  11. Ethyl 6-(4-fluoro­phen­yl)-4-hy­droxy-2-oxo-4-trifluoro­meth­yl-1,3-diazinane-5-carboxyl­ate monohydrate

    PubMed Central

    Li, Gong-Chun; Wu, Chang-Zeng; Guo, Li-Li; Yang, Feng-Ling

    2011-01-01

    The asymmetric unit of the title compound, C14H14F4N2O4·H2O, contains two crystallographically independent organic mol­ecules and two water mol­ecules. The two 1,3-diazinane rings adopt a half-chair conformation and the dihedral angles between their mean planes and those of the benzene rings are 75.65 (4)° and 49.41 (3)° in the two mol­ecules. The crystal structure is stabilized by inter­molecular O—H⋯O and N—H⋯O hydrogen bonds. PMID:21837100

  12. Cyclopeptides containing the DEKS motif as conformationally restricted collagen telopeptide analogues: synthesis and conformational analysis.

    PubMed

    Wodtke, Robert; Ruiz-Gómez, Gloria; Kuchar, Manuela; Pisabarro, M Teresa; Novotná, Pavlina; Urbanová, Marie; Steinbach, Jörg; Pietzsch, Jens; Löser, Reik

    2015-02-14

    The collagen telopeptides play an important role for lysyl oxidase-mediated crosslinking, a process which is deregulated during tumour progression. The DEKS motif which is located within the N-terminal telopeptide of the α1 chain of type I collagen has been suggested to adopt a βI-turn conformation upon docking to its triple-helical receptor domain, which seems to be critical for lysyl oxidase-catalysed deamination and subsequent crosslinking by Schiff-base formation. Herein, the design and synthesis of cyclic peptides which constrain the DEKS sequence in a β-turn conformation will be described. Lysine-side chain attachment to 2-chlorotrityl chloride-modified polystyrene resin followed by microwave-assisted solid-phase peptide synthesis and on-resin cyclisation allowed for an efficient access to head-to-tail cyclised DEKS-derived cyclic penta- and hexapeptides. An N(ε)-(4-fluorobenzoyl)lysine residue was included in the cyclopeptides to allow their potential radiolabelling with fluorine-18 for PET imaging of lysyl oxidase. Conformational analysis by (1)H NMR and chiroptical (electronic and vibrational CD) spectroscopy together with MD simulations demonstrated that the concomitant incorporation of a D-proline and an additional lysine for potential radiolabel attachment accounts for a reliable induction of the desired βI-turn structure in the DEKS motif in both DMSO and water as solvents. The stabilised conformation of the cyclohexapeptide is further reflected by its resistance to trypsin-mediated degradation. In addition, the deaminated analogue containing allysine in place of lysine has been synthesised via the corresponding ε-hydroxynorleucine containing cyclohexapeptide. Both ε-hydroxynorleucine and allysine containing cyclic hexapeptides have been subjected to conformational analysis in the same manner as the lysine-based parent structure. Thus, both a conformationally restricted lysyl oxidase substrate and product have been synthetically accessed, which

  13. Conformal superalgebras via tractor calculus

    NASA Astrophysics Data System (ADS)

    Lischewski, Andree

    2015-01-01

    We use the manifestly conformally invariant description of a Lorentzian conformal structure in terms of a parabolic Cartan geometry in order to introduce a superalgebra structure on the space of twistor spinors and normal conformal vector fields formulated in purely algebraic terms on parallel sections in tractor bundles. Via a fixed metric in the conformal class, one reproduces a conformal superalgebra structure that has been considered in the literature before. The tractor approach, however, makes clear that the failure of this object to be a Lie superalgebra in certain cases is due to purely algebraic identities on the spinor module and to special properties of the conformal holonomy representation. Moreover, it naturally generalizes to higher signatures. This yields new formulas for constructing new twistor spinors and higher order normal conformal Killing forms out of existing ones, generalizing the well-known spinorial Lie derivative. Moreover, we derive restrictions on the possible dimension of the space of twistor spinors in any metric signature.

  14. Pyranose sulfamates: conformation and hydrogen bonding

    NASA Astrophysics Data System (ADS)

    Kubicki, Maciej; Codding, Penelope W.; Litster, Stephen A.; Szkaradziñska, Maria B.; Bassyouni, Hanan A. R.

    1999-01-01

    The crystal structure of a new anticonvulsant drug, topiramate — 2,3:4,5-bis- O-(1-methylethylidene)- β-D-fructopyranose sulfamate ( 1), together with those of three similar but biologically almost inactive sugar sulfamates: 4,5- O-cyclohexylidene-2,3- O-(1-methyl-ethylidene)- β-D-fructopyranose sulfamate ( 2), 2,3:- O-(1-methylethylidene)- β-D-fructo-pyranose sulfamate ( 3), and 1,2:3,4-bis- O-(1-methylethylidene)- α-D-galactopyranose sulfamate ( 4), have been determined by X-rays. The pyranose rings adopt distorted twist-boat 2S O conformations as a result of flattening of the chair conformation, observed in free pyranoses, by the fused five-membered ring(s). In 3 an unfavourable gauche-trans conformation about C1-C2 bond is observed. The active compound, topiramate ( 1), shows, in comparison with the other three compounds, a different disposition of nitrogen and oxygen atoms from the sulfamate group with respect to the O1-S1 bond. As a result, the nitrogen atom in 1 is ca. 1 Å farther from the O6 pyranose ring oxygen atom than in the other three compounds. This difference describes the mutual disposition of the hydrophilic and hydrophobic parts of the molecule, and can be related to the difference in biological activity. In all compounds, hydrogen bonds connect molecules into three-dimensional networks; simple chains and more complicated rings are found and described using the graph set notation.

  15. Molecular Dynamics Studies on the Conformational Transitions of Adenylate Kinase: A Computational Evidence for the Conformational Selection Mechanism

    PubMed Central

    Ping, Jie; Hao, Pei; Li, Yi-Xue; Wang, Jing-Fang

    2013-01-01

    Escherichia coli adenylate kinase (ADK) is a monomeric phosphotransferase enzyme that catalyzes reversible transfer of phosphoryl group from ATP to AMP with a large-scale domain motion. The detailed mechanism for this conformational transition remains unknown. In the current study, we performed long time-scale molecular dynamics simulations on both open and closed states of ADK. Based on the structural analyses of the simulation trajectories, we detected over 20 times conformational transitions between the open and closed states of ADK and identified two novel conformations as intermediate states in the catalytic processes. With these findings, we proposed a possible mechanism for the large-scale domain motion of Escherichia coli ADK and its catalytic process: (1) the substrate free ADK adopted an open conformation; (2) ATP bound with LID domain closure; (3) AMP bound with NMP domain closure; (4) phosphoryl transfer occurred with ATP, and AMP converted into two ADPs, and no conformational transition was detected in the enzyme; (5) LID domain opened with one ADP released; (6) another ADP released with NMP domain open. As both open and closed states sampled a wide range of conformation transitions, our simulation strongly supported the conformational selection mechanism for Escherichia coli ADK. PMID:23936827

  16. Stories of Aboriginal Transracial Adoption

    ERIC Educational Resources Information Center

    Nuttgens, Simon

    2013-01-01

    Despite the significant number of transracial Aboriginal adoptions that have taken place in Canada, little research is available that addresses the psychological and psychosocial ramifications for the children involved. The scant literature that does exist raises concerns about the psychological impact of this type of adoption. The present…

  17. Faculty Adoption of Educational Technology

    ERIC Educational Resources Information Center

    Moser, Franziska Zellweger

    2007-01-01

    Although faculty support has been identified as a critical factor in the success of educational-technology programs, many people involved in such efforts underestimate the complexities of integrating technology into teaching. In this article, the author proposes an adoption cycle to help tackle the complex issue of technology adoption for…

  18. The Temporal Context of Adoption.

    ERIC Educational Resources Information Center

    Pontius, Steven K.

    This paper analyzes the amount of time required by farmers in four villages on the western edge of the central plain of Thailand to adopt four agricultural innovations--fertilizer, herbicide, insecticide, and fungicide. The general objective is to help researchers interested in the relationship of the adoption of new ideas to economic development…

  19. OSI Conformance Testing for Bibliographic Applications.

    ERIC Educational Resources Information Center

    Arbez, Gilbert; Swain, Leigh

    1990-01-01

    Describes the development of Open Systems Interconnection (OSI) conformance testing sites, conformance testing tools, and conformance testing services. Discusses related topics such as interoperability testing, arbitration testing, and international harmonization of conformance testing. A glossary is included. (24 references) (SD)

  20. Leaf growth is conformal.

    PubMed

    Alim, Karen; Armon, Shahaf; Shraiman, Boris I; Boudaoud, Arezki

    2016-01-01

    Growth pattern dynamics lie at the heart of morphogenesis. Here, we investigate the growth of plant leaves. We compute the conformal transformation that maps the contour of a leaf at a given stage onto the contour of the same leaf at a later stage. Based on the mapping we predict the local displacement field in the leaf blade and find it to agree with the experimentally measured displacement field to 92%. This approach is applicable to any two-dimensional system with locally isotropic growth, enabling the deduction of the whole growth field just from observation of the tissue contour. PMID:27597439

  1. Metamaterials with conformational nonlinearity

    NASA Astrophysics Data System (ADS)

    Lapine, Mikhail; Shadrivov, Ilya V.; Powell, David A.; Kivshar, Yuri S.

    2011-11-01

    Within a decade of fruitful development, metamaterials became a prominent area of research, bridging theoretical and applied electrodynamics, electrical engineering and material science. Being man-made structures, metamaterials offer a particularly useful playground to develop interdisciplinary concepts. Here we demonstrate a novel principle in metamaterial assembly which integrates electromagnetic, mechanical, and thermal responses within their elements. Through these mechanisms, the conformation of the meta-molecules changes, providing a dual mechanism for nonlinearity and offering nonlinear chirality. Our proposal opens a wide road towards further developments of nonlinear metamaterials and photonic structures, adding extra flexibility to their design and control.

  2. Characteristics of adopted juvenile delinquents.

    PubMed

    Kim, W J; Zrull, J P; Davenport, C W; Weaver, M

    1992-05-01

    There have been many reports describing the uniqueness of adopted children and adolescents' delinquent behaviors in terms of both their delinquent characteristics and courts' treatment of them. A total of 43 adopted juveniles, 32 extrafamilial (1.0%) and 11 intrafamilial (0.3%) adoptions were initially identified out of 3,280 juvenile delinquents. The adopted subjects were then compared with the demographically matched and offense matched nonadopted subjects. The family variables, such as marital and employment status of parents, were significantly different. However, there were only a few discernible trends, and in general there were no significant differences between the adopted and nonadopted juveniles in terms of their offense characteristics and dispositions. PMID:1592787

  3. Conformational selection or induced fit? 50 years of debate resolved

    PubMed Central

    Edelstein, Stuart

    2011-01-01

    Exactly 50 years ago, biochemists raised the question of the mechanism of the conformational change that mediates “allosteric” interactions between regulatory sites and biologically active sites in regulatory/receptor proteins. Do the different conformations involved already exist spontaneously in the absence of the regulatory ligands (Monod-Wyman-Changeux), such that the complementary protein conformation would be selected to mediate signal transduction, or do particular ligands induce the receptor to adopt the conformation best suited to them (Koshland-Nemethy-Filmer—induced fit)? This is not just a central question for biophysics, it also has enormous importance for drug design. Recent advances in techniques have allowed detailed experimental and theoretical comparisons with the formal models of both scenarios. Also, it has been shown that mutated receptors can adopt constitutively active confirmations in the absence of ligand. There have also been demonstrations that the atomic resolution structures of the same protein are essentially the same whether ligand is bound or not. These and other advances in past decades have produced a situation where the vast majority of the data using different categories of regulatory proteins (including regulatory enzymes, ligand-gated ion channels, G protein-coupled receptors, and nuclear receptors) support the conformational selection scheme of signal transduction. PMID:21941598

  4. Conformally symmetric traversable wormholes

    SciTech Connect

    Boehmer, Christian G.; Harko, Tiberiu; Lobo, Francisco S. N.

    2007-10-15

    Exact solutions of traversable wormholes are found under the assumption of spherical symmetry and the existence of a nonstatic conformal symmetry, which presents a more systematic approach in searching for exact wormhole solutions. In this work, a wide variety of solutions are deduced by considering choices for the form function, a specific linear equation of state relating the energy density and the pressure anisotropy, and various phantom wormhole geometries are explored. A large class of solutions impose that the spatial distribution of the exotic matter is restricted to the throat neighborhood, with a cutoff of the stress-energy tensor at a finite junction interface, although asymptotically flat exact solutions are also found. Using the 'volume integral quantifier', it is found that the conformally symmetric phantom wormhole geometries may, in principle, be constructed by infinitesimally small amounts of averaged null energy condition violating matter. Considering the tidal acceleration traversability conditions for the phantom wormhole geometry, specific wormhole dimensions and the traversal velocity are also deduced.

  5. Eikonalization of conformal blocks

    SciTech Connect

    Fitzpatrick, A. Liam; Kaplan, Jared; Walters, Matthew T.; Wang, Junpu

    2015-09-03

    Classical field configurations such as the Coulomb potential and Schwarzschild solution are built from the t-channel exchange of many light degrees of freedom. We study the CFT analog of this phenomenon, which we term the 'eikonalization' of conformal blocks. We show that when an operator T appears in the OPE Ο(x)Ο(0), then the large spin Fock space states [TT···T] also appear in this OPE with a computable coefficient. The sum over the exchange of these Fock space states in an correlator build the classical 'T field' in the dual AdS description. In some limits the sum of all Fock space exchanges can be represented as the exponential of a single T exchange in the 4-pt correlator of O. Our results should be useful for systematizing 1/ℓ perturbation theory in general CFTs and simplifying the computation of large spin OPE coefficients. As examples we obtain the leading log ℓ dependence of Fock space conformal block coefficients, and we directly compute the OPE coefficients of the simplest ‘triple-trace’ operators.

  6. Eikonalization of conformal blocks

    DOE PAGESBeta

    Fitzpatrick, A. Liam; Kaplan, Jared; Walters, Matthew T.; Wang, Junpu

    2015-09-03

    Classical field configurations such as the Coulomb potential and Schwarzschild solution are built from the t-channel exchange of many light degrees of freedom. We study the CFT analog of this phenomenon, which we term the 'eikonalization' of conformal blocks. We show that when an operator T appears in the OPE Ο(x)Ο(0), then the large spin Fock space states [TT···T]ℓ also appear in this OPE with a computable coefficient. The sum over the exchange of these Fock space states in an correlator build the classical 'T field' in the dual AdS description. In some limits the sum of all Fock spacemore » exchanges can be represented as the exponential of a single T exchange in the 4-pt correlator of O. Our results should be useful for systematizing 1/ℓ perturbation theory in general CFTs and simplifying the computation of large spin OPE coefficients. As examples we obtain the leading log ℓ dependence of Fock space conformal block coefficients, and we directly compute the OPE coefficients of the simplest ‘triple-trace’ operators.« less

  7. Recent Advances in Conformal Gravity

    NASA Astrophysics Data System (ADS)

    O'Brien, James; Chaykov, Spasen

    2016-03-01

    In recent years, significant advances have been made in alternative gravitational theories. Although MOND remains the leading candidate among the alternative models, Conformal Gravity has been studied by Mannheim and O'Brien to solve the rotation curve problem without the need for dark matter. Recently, Mannheim, O'Brien and Chaykov have begun solving other gravitational questions in Conformal Gravity. In this presentation, we highlight the new work of Conformal Gravity's application to random motions of clusters (the original Zwicky problem), gravitational bending of light, gravitational lensing and a very recent survey of dwarf galaxy rotation curves. We will show in each case that Conformal Gravity can provide an accurate explanation and prediction of the data without the need for dark matter. Coupled with the fact that Conformal Gravity is a fully re-normalizable metric theory of gravity, these results help to push Conformal Gravity onto a competitive stage against other alternative models.

  8. Conformal Gravity and Gravitational Waves

    NASA Astrophysics Data System (ADS)

    Fabbri, Luca; Paranjape, M. B.

    We consider monochromatic, plane gravitational waves in a conformally invariant theory of general relativity. We show that the simple, standard ansatz for the metric, usually that which is taken for the linearized theory of these waves, is reducible to the metric of Minkowski spacetime via a sequence of conformal and coordinate transformations. This implies that we have in fact, exact plane wave solutions. However they are simply coordinate/conformal artifacts. As a consequence, they carry no energy.

  9. Killing and conformal Killing tensors

    NASA Astrophysics Data System (ADS)

    Heil, Konstantin; Moroianu, Andrei; Semmelmann, Uwe

    2016-08-01

    We introduce an appropriate formalism in order to study conformal Killing (symmetric) tensors on Riemannian manifolds. We reprove in a simple way some known results in the field and obtain several new results, like the classification of conformal Killing 2-tensors on Riemannian products of compact manifolds, Weitzenböck formulas leading to non-existence results, and construct various examples of manifolds with conformal Killing tensors.

  10. Loop Virasoro Lie conformal algebra

    SciTech Connect

    Wu, Henan Chen, Qiufan; Yue, Xiaoqing

    2014-01-15

    The Lie conformal algebra of loop Virasoro algebra, denoted by CW, is introduced in this paper. Explicitly, CW is a Lie conformal algebra with C[∂]-basis (L{sub i} | i∈Z) and λ-brackets [L{sub i} {sub λ} L{sub j}] = (−∂−2λ)L{sub i+j}. Then conformal derivations of CW are determined. Finally, rank one conformal modules and Z-graded free intermediate series modules over CW are classified.

  11. Reflections on conformal spectra

    NASA Astrophysics Data System (ADS)

    Kim, Hyungrok; Kravchuk, Petr; Ooguri, Hirosi

    2016-04-01

    We use modular invariance and crossing symmetry of conformal field theory to reveal approximate reflection symmetries in the spectral decompositions of the partition function in two dimensions in the limit of large central charge and of the four-point function in any dimension in the limit of large scaling dimensions Δ0 of external operators. We use these symmetries to motivate universal upper bounds on the spectrum and the operator product expansion coefficients, which we then derive by independent techniques. Some of the bounds for four-point functions are valid for finite Δ0 as well as for large Δ0. We discuss a similar symmetry in a large spacetime dimension limit. Finally, we comment on the analogue of the Cardy formula and sparse light spectrum condition for the four-point function.

  12. Capturing Chromosome Conformation

    NASA Astrophysics Data System (ADS)

    Dekker, Job; Rippe, Karsten; Dekker, Martijn; Kleckner, Nancy

    2002-02-01

    We describe an approach to detect the frequency of interaction between any two genomic loci. Generation of a matrix of interaction frequencies between sites on the same or different chromosomes reveals their relative spatial disposition and provides information about the physical properties of the chromatin fiber. This methodology can be applied to the spatial organization of entire genomes in organisms from bacteria to human. Using the yeast Saccharomyces cerevisiae, we could confirm known qualitative features of chromosome organization within the nucleus and dynamic changes in that organization during meiosis. We also analyzed yeast chromosome III at the G1 stage of the cell cycle. We found that chromatin is highly flexible throughout. Furthermore, functionally distinct AT- and GC-rich domains were found to exhibit different conformations, and a population-average 3D model of chromosome III could be determined. Chromosome III emerges as a contorted ring.

  13. Influence of Crystal Packing on Global Protein Conformation

    NASA Astrophysics Data System (ADS)

    Ahlstrom, Logan; Miyashita, Osamu

    2011-10-01

    X-ray crystallography is the most robust method for solving protein structure. However, packing forces in the crystal lattice select just a snapshot of a protein's conformational ensemble, whereas proteins are flexible and can adopt different conformations. Here we compare molecular dynamics (MD) simulations in solution and the crystal lattice to add dynamical insight to the static X-ray images of proteins. As a model system, we consider the λ Cro dimer, whose solved X-ray structures range from a ``closed'' to an ``open'' global conformation. Free energy profiles depicting the conformational space sampled by the dimer in solution show some reported structures correspond to stable states. Yet other conformations, while accessible, lie higher in energy, indicating the effect of crystal packing. Subsequent crystal MD simulations estimated the strength of packing interfaces in the lattice, showing the influence of crystal form and mutation in stabilizing different dimer conformations. Our quantitative results will aid analysis of X-ray data in establishing protein structure-function relationships.

  14. Oligothiophene wires: impact of torsional conformation on the electronic structure.

    PubMed

    Kislitsyn, D A; Taber, B N; Gervasi, C F; Zhang, L; Mannsfeld, S C B; Prell, J S; Briseno, A L; Nazin, G V

    2016-02-14

    Charge transport in polymer- and oligomer-based semiconductor materials depends strongly on the structural ordering of the constituent molecules. Variations in molecular conformations influence the electronic structures of polymers and oligomers, and thus impact their charge-transport properties. In this study, we used Scanning Tunneling Microscopy and Spectroscopy (STM/STS) to investigate the electronic structures of different alkyl-substituted oligothiophenes displaying varied torsional conformations on the Au(111) surface. STM imaging showed that on Au(111), oligothiophenes self-assemble into chain-like structures, binding to each other via interdigitated alkyl ligands. The molecules adopted distinct planar conformations with alkyl ligands forming cis- or trans- mutual orientations. For each molecule, by using STS mapping, we identify a progression of particle-in-a-box-like states corresponding to the LUMO, LUMO+1 and LUMO+2 orbitals. Analysis of STS data revealed very similar unoccupied molecular orbital energies for different possible molecular conformations. By using density functional theory calculations, we show that the lack of variation in molecular orbital energies among the different oligothiophene conformers implies that the effect of the Au-oligothiophene interaction on molecular orbital energies is nearly identical for all studied torsional conformations. Our results suggest that cis-trans torsional disorder may not be a significant source of electronic disorder and charge carrier trapping in organic semiconductor devices based on oligothiophenes. PMID:26804474

  15. Replacement between conformity and counter-conformity in consumption decisions.

    PubMed

    Chou, Ting-Jui; Chang, En-Chung; Dai, Qi; Wong, Veronica

    2013-02-01

    This study assessed, in a Chinese context, how self-esteem interacts with perceived similarity and uniqueness to yield cognitive dissonance, and whether the dissonance leads to self-reported conformity or counter-conformity behavior. Participants were 408 respondents from 4 major Chinese cities (M age = 33.0 yr., SD = 4.3; 48% men). Self-perceptions of uniqueness, similarity, cognitive dissonance, self-esteem and need to behave in conformity or counter-conformity were measured. A theoretical model was assessed in four situations, relating the ratings of self-esteem and perceived similarity/uniqueness to the way other people at a wedding were dressed, and the resultant cognitive dissonance and conformity/ counter-conformity behavior. Regardless of high or low self-esteem, all participants reported cognitive dissonance when they were told that they were dressed extremely similarly to or extremely differently from the other people attending the wedding. However, the conforming/counter-conforming strategies used by participants to resolve the cognitive dissonance differed. When encountering dissonance induced by the perceived extreme uniqueness of dress, participants with low self-esteem tended to say they would dress next time so as to conform with the way others were dressed, while those with high self-esteem indicated they would continue their counter-conformity in attire. When encountering dissonance induced by the perceived extreme similarity to others, both those with high and low self-esteem tended to say they would dress in an unorthodox manner to surprise other people in the future. PMID:23654033

  16. Multiple Conformations of E. Coli Hsp90 in Solution: Insights Into the Conformational Dynamics of Hsp90

    SciTech Connect

    Krukenberg, K.A.; Forster, F.; Rice, L.M.; Sali, A.; Agard, D.A.

    2009-05-20

    Hsp90, an essential eukaryotic chaperone, depends upon its intrinsic ATPase activity for function. Crystal structures of the bacterial Hsp90 homolog, HtpG, and the yeast Hsp90 reveal large domain rearrangements between the nucleotide-free and the nucleotide-bound forms. We used small-angle X-ray scattering and recently developed molecular modeling methods to characterize the solution structure of HtpG and demonstrate how it differs from known Hsp90 conformations. In addition to this HtpG conformation, we demonstrate that under physiologically relevant conditions, multiple conformations coexist in equilibrium. In solution, nucleotide-free HtpG adopts a more extended conformation than observed in the crystal, and upon the addition of AMPPNP, HtpG is in equilibrium between this open state and a closed state that is in good agreement with the yeast AMPPNP crystal structure. These studies provide a unique view of Hsp90 conformational dynamics and provide a model for the role of nucleotide in effecting conformational change.

  17. A study into the effects of protein binding on nucleotide conformation.

    PubMed Central

    Moodie, S L; Thornton, J M

    1993-01-01

    In this study, we examine the effects of binding to protein upon nucleotide conformation, by the comparison of X-ray crystal structures of free and protein-bound nucleotides. A dataset of structurally non-homologous protein-nucleotide complexes was derived from the Brookhaven Protein Data Bank by a novel protocol of dual sequential and structural alignments, and a dataset of native nucleotide structures was obtained from the Cambridge Structural Database. The nucleotide torsion angles and sugar puckers, which describe nucleotide conformation, were analysed in both datasets and compared. Differences between them are described and discussed. Overall, the nucleotides were found to bind in low energy conformations, not significantly different from their 'free' conformations except that they adopted an extended conformation in preference to the 'closed' structure predominantly observed by free nucleotide. The archetypal conformation of a protein-bound nucleotide is derived from these observations. PMID:8464727

  18. Classical Virasoro irregular conformal block

    NASA Astrophysics Data System (ADS)

    Rim, Chaiho; Zhang, Hong

    2015-07-01

    Virasoro irregular conformal block with arbitrary rank is obtained for the classical limit or equivalently Nekrasov-Shatashvili limit using the beta-deformed irregular matrix model (Penner-type matrix model for the irregular conformal block). The same result is derived using the generalized Mathieu equation which is equivalent to the loop equation of the irregular matrix model.

  19. Conformal gravity and time

    NASA Astrophysics Data System (ADS)

    Hazboun, Jeffrey Shafiq

    2014-10-01

    Cartan geometry provides a rich formalism from which to look at various geometrically motivated extensions to general relativity. In this manuscript, we start by motivating reasons to extend the theory of general relativity. We then introduce the reader to our technique, called the quotient manifold method, for extending the geometry of spacetime. We will specifically look at the class of theories formed from the various quotients of the conformal group. Starting with the conformal symmetries of Euclidean space, we construct a manifold where time manifests as a part of the geometry. Though there is no matter present in the geome- try studied here, geometric terms analogous to dark energy and dark matter appear when we write down the Einstein tensor. Specifically, the quotient of the conformal group of Euclidean four-space by its Weyl subgroup results in a geometry possessing many of the properties of relativistic phase space, including both a natural symplectic form and nondegenerate Killing metric. We show the general solution possesses orthogonal Lagrangian submanifolds, with the induced metric and the spin connection on the submanifolds necessarily Lorentzian, despite the Euclidean starting point. By examining the structure equations of the biconformal space in an orthonormal frame adapted to its phase space properties, we also find two new tensor fields exist in this geometry, not present in Riemannian geometry. The first is a combination of the Weyl vector with the scale factor on the metric, and determines the time-like directions on the submanifolds. The second comes from the components of the spin connection, symmetric with respect to the new metric. Though this field comes from the spin connection, it transforms ho- mogeneously. Finally, we show in the absence of Cartan curvature or sources, the configuration space has geometric terms equivalent to a perfect fluid and a cosmological constant. We complete the analysis of this homogeneous space by

  20. Projectors, shadows, and conformal blocks

    NASA Astrophysics Data System (ADS)

    Simmons-Duffin, David

    2014-04-01

    We introduce a method for computing conformal blocks of operators in arbitrary Lorentz representations in any spacetime dimension, making it possible to apply bootstrap techniques to operators with spin. The key idea is to implement the "shadow formalism" of Ferrara, Gatto, Grillo, and Parisi in a setting where conformal invariance is manifest. Conformal blocks in d-dimensions can be expressed as integrals over the projective null-cone in the "embedding space" d+1,1. Taking care with their analytic structure, these integrals can be evaluated in great generality, reducing the computation of conformal blocks to a bookkeeping exercise. To facilitate calculations in four-dimensional CFTs, we introduce techniques for writing down conformally-invariant correlators using auxiliary twistor variables, and demonstrate their use in some simple examples.

  1. Personality disorders in adopted versus non-adopted adults.

    PubMed

    Westermeyer, Joseph; Yoon, Gihyun; Amundson, Carla; Warwick, Marion; Kuskowski, Michael A

    2015-04-30

    The goal of this epidemiological study was to investigate lifetime history and odds ratios of personality disorders in adopted and non-adopted adults using a nationally representative sample. Data, drawn from the National Epidemiological Survey on Alcohol and Related Conditions (NESARC), were compared in adopted (n=378) versus non-adopted (n=42,503) adults to estimate the odds of seven personality disorders using logistic regression analyses. The seven personality disorders were histrionic, antisocial, avoidant, paranoid, schizoid, obsessive-compulsive, and dependent personality disorder. Adoptees had a 1.81-fold increase in the odds of any personality disorder compared with non-adoptees. Adoptees had increased odds of histrionic, antisocial, avoidant, paranoid, schizoid, and obsessive-compulsive personality disorder compared with non-adoptees. Two risk factors associated with lifetime history of a personality disorder in adoptees compared to non-adoptees were (1) being in the age cohort 18-29 years (but no difference in the age 30-44 cohort), using the age 45 or older cohort as the reference and (2) having 12 years of education (but no difference in higher education groups), using the 0-11 years of education as the reference. These findings support the higher rates of personality disorders among adoptees compared to non-adoptees. PMID:25752207

  2. Warped conformal field theory

    NASA Astrophysics Data System (ADS)

    Detournay, Stéphane; Hartman, Thomas; Hofman, Diego M.

    2012-12-01

    We study field theories in two spacetime dimensions invariant under a chiral scaling symmetry that acts only on right-movers. The local symmetries include one copy of the Virasoro algebra and a U(1) current algebra. This differs from the two-dimensional conformal group but in some respects is equally powerful in constraining the theory. In particular, the symmetries on a torus lead to modular covariance of the partition function, which is used to derive a universal formula for the asymptotic density of states. For an application we turn to the holographic description of black holes in quantum gravity, motivated by the fact that the symmetries in the near-horizon geometry of any extremal black hole are identical to those of a two-dimensional field theory with chiral scaling. We consider two examples: black holes in warped AdS3 in topologically massive gravity and in string theory. In both cases, the density of states in the two-dimensional field theory reproduces the Bekenstein-Hawking entropy of black holes in the gravity theory.

  3. Dynamics of protein conformations

    NASA Astrophysics Data System (ADS)

    Stepanova, Maria

    2010-10-01

    A novel theoretical methodology is introduced to identify dynamic structural domains and analyze local flexibility in proteins. The methodology employs a multiscale approach combining identification of essential collective coordinates based on the covariance analysis of molecular dynamics trajectories, construction of the Mori projection operator with these essential coordinates, and analysis of the corresponding generalized Langevin equations [M.Stepanova, Phys.Rev.E 76(2007)051918]. Because the approach employs a rigorous theory, the outcomes are physically transparent: the dynamic domains are associated with regions of relative rigidity in the protein, whereas off-domain regions are relatively soft. This also allows scoring the flexibility in the macromolecule with atomic-level resolution [N.Blinov, M.Berjanskii, D.S.Wishart, and M.Stepanova, Biochemistry, 48(2009)1488]. The applications include the domain coarse-graining and characterization of conformational stability in protein G and prion proteins. The results are compared with published NMR experiments. Potential applications for structural biology, bioinformatics, and drug design are discussed.

  4. Re an Adoption Application (Surrogacy)

    PubMed

    1987-03-01

    In England, it is illegal under the Adoption Act 1958 to pay or reward anyone in an effort to adopt a child. A family court was asked in this case whether a surrogacy arrangement involving the payment of 5,000 pounds violated the Act. The applicants, a husband and wife, were unable to have children and had entered into an informal arrangement with a woman who agreed to engage in sexual intercourse with the husband and bear a child for the couple in exchange for 10,000 pounds. Because the surrogate wrote a book about her experience from which she made money, and sincerely wanted to help out the childless couple, she accepted only half of her fee. Convinced that the surrogate arrangement was not commercial in nature, the court found no violation of English law, authorized the payment to the mother, and authorized adoption of the child by the father and his wife. PMID:11648176

  5. Two quinazolinones: a ring conformational study.

    PubMed

    Swamy, G Y S K; Sridhar, B; Ravikumar, K; Sadanandam, Y S

    2008-02-01

    The molecules of (+/-)-2-(4-methoxyphenyl)-1-phenethyl-2,3-dihydroquinazolin-4(1H)-one, C(23)H(22)N(2)O(2), (I), and (+/-)-2-(1,3-benzodioxol-5-yl)-1-phenethyl-2,3-dihydroquinazolin-4(1H)-one, C(23)H(20)N(2)O(3), (II), have T-shaped forms in the crystal structure. The tetrahydropyrimidine ring in both structures adopts a sofa conformation. Both molecules are linked by N-H...O and C-H...O hydrogen bonds to form sheets built from alternating R(2)(2)(8) and R(4)(4)(26) [R(4)(4)(24) in (II)] edge-fused rings. Additionally, the structures are stabilized by extensive C-H...pi interactions. PMID:18253014

  6. Determinants of internet poker adoption.

    PubMed

    Philander, Kahlil S; Abarbanel, B Lillian

    2014-09-01

    In nearly all jurisdictions, adoption of a new form of gambling has been a controversial and contentious subject. Online gambling has been no different, though there are many aspects that affect online gambling that do not appear in the brick and mortar environment. This study seeks to identify whether demographic, economic, political, technological, and/or sociological determinants contribute to online poker gambling adoption. A theoretical discussion of these categories' importance to online poker is provided and exploratory empirical analysis is used to examine their potential validity. The analysis revealed support for all of the proposed categories of variables thought to be predictive of online gambling legality. PMID:23661279

  7. Adoption Failure: A Social Work Postmortem

    ERIC Educational Resources Information Center

    Kadushin, Alfred; Seidl, Frederick W.

    1971-01-01

    Failed adoption is defined as removal of the adoptive child at any time between placement and legal adoption. A study of failed adoptions in a statewide adoption agency found a failure rate of less than 3 percent. Reasons for failure are analyzed and implications for practice are suggested. (Author)

  8. Canadian Adoption Statistics: 1981-1990.

    ERIC Educational Resources Information Center

    Sobol, Michael P.; Daly, Kerry J.

    1994-01-01

    Obtained data on Canadian adoptions (1981-90) from adoption coordinators of all 10 provinces and 2 territories. Found downward trends in use of adoption as means of family formation across decade. By 1990, most infant adoptions were facilitated by private practitioners and agencies whereas older children were primarily adopted through public…

  9. Towards conformal loop quantum gravity

    NASA Astrophysics Data System (ADS)

    H-T Wang, Charles

    2006-03-01

    A discussion is given of recent developments in canonical gravity that assimilates the conformal analysis of gravitational degrees of freedom. The work is motivated by the problem of time in quantum gravity and is carried out at the metric and the triad levels. At the metric level, it is shown that by extending the Arnowitt-Deser-Misner (ADM) phase space of general relativity (GR), a conformal form of geometrodynamics can be constructed. In addition to the Hamiltonian and Diffeomorphism constraints, an extra first class constraint is introduced to generate conformal transformations. This phase space consists of York's mean extrinsic curvature time, conformal three-metric and their momenta. At the triad level, the phase space of GR is further enlarged by incorporating spin-gauge as well as conformal symmetries. This leads to a canonical formulation of GR using a new set of real spin connection variables. The resulting gravitational constraints are first class, consisting of the Hamiltonian constraint and the canonical generators for spin-gauge and conformorphism transformations. The formulation has a remarkable feature of being parameter-free. Indeed, it is shown that a conformal parameter of the Barbero-Immirzi type can be absorbed by the conformal symmetry of the extended phase space. This gives rise to an alternative approach to loop quantum gravity that addresses both the conceptual problem of time and the technical problem of functional calculus in quantum gravity.

  10. Logarithmic conformal field theory

    NASA Astrophysics Data System (ADS)

    Gainutdinov, Azat; Ridout, David; Runkel, Ingo

    2013-12-01

    Conformal field theory (CFT) has proven to be one of the richest and deepest subjects of modern theoretical and mathematical physics research, especially as regards statistical mechanics and string theory. It has also stimulated an enormous amount of activity in mathematics, shaping and building bridges between seemingly disparate fields through the study of vertex operator algebras, a (partial) axiomatisation of a chiral CFT. One can add to this that the successes of CFT, particularly when applied to statistical lattice models, have also served as an inspiration for mathematicians to develop entirely new fields: the Schramm-Loewner evolution and Smirnov's discrete complex analysis being notable examples. When the energy operator fails to be diagonalisable on the quantum state space, the CFT is said to be logarithmic. Consequently, a logarithmic CFT is one whose quantum space of states is constructed from a collection of representations which includes reducible but indecomposable ones. This qualifier arises because of the consequence that certain correlation functions will possess logarithmic singularities, something that contrasts with the familiar case of power law singularities. While such logarithmic singularities and reducible representations were noted by Rozansky and Saleur in their study of the U (1|1) Wess-Zumino-Witten model in 1992, the link between the non-diagonalisability of the energy operator and logarithmic singularities in correlators is usually ascribed to Gurarie's 1993 article (his paper also contains the first usage of the term 'logarithmic conformal field theory'). The class of CFTs that were under control at this time was quite small. In particular, an enormous amount of work from the statistical mechanics and string theory communities had produced a fairly detailed understanding of the (so-called) rational CFTs. However, physicists from both camps were well aware that applications from many diverse fields required significantly more

  11. CONFORMANCE IMPROVEMENT USING GELS

    SciTech Connect

    Randall S. Seright

    2002-02-28

    This technical progress report describes work performed from June 20 through December 19, 2001, for the project, ''Conformance Improvement Using Gels''. Interest has increased in some new polymeric products that purport to substantially reduce permeability to water while causing minimum permeability reduction to oil. In view of this interest, we are currently studying BJ's Aqua Con. Results from six corefloods revealed that the Aqua Con gelant consistently reduced permeability to water more than that to oil. However, the magnitude of the disproportionate permeability reduction varied significantly for the various experiments. Thus, as with most materials tested to date, the issue of reproducibility and control of the disproportionate permeability remains to be resolved. Concern exists about the ability of gels to resist washout after placement in fractures. We examined whether a width constriction in the middle of a fracture would cause different gel washout behavior upstream versus downstream of the constriction. Tests were performed using a formed Cr(III)-acetate-HPAM gel in a 48-in.-long fracture with three sections of equal length, but with widths of 0.08-, 0.02-, and 0.08-in., respectively. The pressure gradients during gel extrusion (i.e., placement) were similar in the two 0.08-in.-wide fracture sections, even though they were separated by a 0.02-in.-wide fracture section. The constriction associated with the middle fracture section may have inhibited gel washout during the first pulse of brine injection after gel placement. However, during subsequent phases of brine injection, the constriction did not inhibit washout in the upstream fracture section any more than in the downstream section.

  12. Why Adoption of Standards Matters

    ERIC Educational Resources Information Center

    Journal of Staff Development, 2016

    2016-01-01

    A total of 39 states have adopted, adapted, or endorsed the Standards for Professional Learning, including the standards issued in 2011 (labeled in red) and those published earlier (labeled in blue). Making a commitment to the standards is a commitment to continuous learning for all educators in a school.

  13. Internet Adoption: An Empirical Investigation

    ERIC Educational Resources Information Center

    Ma, Junzhao

    2011-01-01

    The Internet has brought significant changes to the retail industry because it revolutionizes how information is transmitted and accessed. The main objective of this research is to enhance our understanding of people's adoption of the Internet and its implications for retail competition. This dissertation consists of two essays. The first essay…

  14. Has the Academy Adopted TQM?

    ERIC Educational Resources Information Center

    Birnbaum, Robert; Deshotels, Judy

    1999-01-01

    A survey of 469 colleges and universities assessed the degree to which colleges and universities have adopted total quality management (TQM) or continuous quality improvement (CQI) techniques. Results suggest use of TQM/CQI is lower than predicted, at about 13% of institutions. Variations in extent of use of the approach are discussed. (MSE)

  15. Adoptive immunotherapy against ovarian cancer.

    PubMed

    Mittica, Gloria; Capellero, Sonia; Genta, Sofia; Cagnazzo, Celeste; Aglietta, Massimo; Sangiolo, Dario; Valabrega, Giorgio

    2016-01-01

    The standard front-line therapy for epithelial ovarian cancer (EOC) is combination of debulking surgery and platinum-based chemotherapy. Nevertheless, the majority of patients experience disease recurrence. Although extensive efforts to find new therapeutic options, cancer cells invariably develop drug resistance and disease progression. New therapeutic strategies are needed to improve prognosis of patients with advanced EOC.Recently, several preclinical and clinical studies investigated feasibility and activity of adoptive immunotherapy in EOC. Our aim is to highlight prospective of adoptive immunotherapy in EOC, focusing on HLA-restricted Tumor Infiltrating Lymphocytes (TILs), and MHC-independent immune effectors such as natural killer (NK), and cytokine-induced killer (CIK). Adoptive cell therapy (ACT) has shown activity in several pre-clinical models. Available preclinical and clinical data suggest that adoptive cell therapy may provide the best benefit in settings of low tumor burden, minimal residual disease, or maintenance therapy. Further studies are needed to better define the optimal clinical setting. PMID:27188274

  16. Adoption Issues, Trends and Networking.

    ERIC Educational Resources Information Center

    Pierce, William L.

    Teenage women with unplanned pregnancies constitute one of America's greatest challenges in terms of providing good services and sound counseling on options. Only about 7% of teenagers having babies make alternate childrearing plans either through formal adoption or informally with members of their families. The emphasis on making teenagers good…

  17. Conformational changes of adsorbed proteins

    NASA Astrophysics Data System (ADS)

    Allen, Scott

    2005-03-01

    The adsorption of bovine serum albumin (BSA) and pepsin to gold surfaces has been studied using surface plasmon resonance (SPR). Proteins are adsorbed from solution onto a gold surface and changes in the conformation of the adsorbed proteins are induced by changing the buffer solution. We selected pH and ionic strength values for the buffer solutions that are known from our circular dichroism measurements to cause conformational changes of the proteins in bulk solution. We find that for both BSA and pepsin the changes in conformation are impeded by the interaction of the protein with the gold surface.

  18. Pressure-induced conformational switch of an interfacial protein.

    PubMed

    Johnson, Quentin R; Lindsay, Richard J; Nellas, Ricky B; Shen, Tongye

    2016-06-01

    A special class of proteins adopts an inactive conformation in aqueous solution and activates at an interface (such as the surface of lipid droplet) by switching their conformations. Lipase, an essential enzyme for breaking down lipids, serves as a model system for studying such interfacial proteins. The underlying conformational switch of lipase induced by solvent condition is achieved through changing the status of the gated substrate-access channel. Interestingly, a lipase was also reported to exhibit pressure activation, which indicates it is drastically active at high hydrostatic pressure. To unravel the molecular mechanism of this unusual phenomenon, we examined the structural changes induced by high hydrostatic pressures (up to 1500 MPa) using molecular dynamics simulations. By monitoring the width of the access channel, we found that the protein undergoes a conformational transition and opens the access channel at high pressures (>100 MPa). Particularly, a disordered amphiphilic α5 region of the protein becomes ordered at high pressure. This positive correlation between the channel opening and α5 ordering is consistent with the early findings of the gating motion in the presence of a water-oil interface. Statistical analysis of the ensemble of conformations also reveals the essential collective motions of the protein and how these motions contribute to gating. Arguments are presented as to why heightened sensitivity to high-pressure perturbation can be a general feature of switchable interfacial proteins. Further mutations are also suggested to validate our observations. Proteins 2016; 84:820-827. © 2016 Wiley Periodicals, Inc. PMID:26967808

  19. Conformational states of the full-length glucagon receptor

    NASA Astrophysics Data System (ADS)

    Yang, Linlin; Yang, Dehua; de Graaf, Chris; Moeller, Arne; West, Graham M.; Dharmarajan, Venkatasubramanian; Wang, Chong; Siu, Fai Y.; Song, Gaojie; Reedtz-Runge, Steffen; Pascal, Bruce D.; Wu, Beili; Potter, Clinton S.; Zhou, Hu; Griffin, Patrick R.; Carragher, Bridget; Yang, Huaiyu; Wang, Ming-Wei; Stevens, Raymond C.; Jiang, Hualiang

    2015-07-01

    Class B G protein-coupled receptors are composed of an extracellular domain (ECD) and a seven-transmembrane (7TM) domain, and their signalling is regulated by peptide hormones. Using a hybrid structural biology approach together with the ECD and 7TM domain crystal structures of the glucagon receptor (GCGR), we examine the relationship between full-length receptor conformation and peptide ligand binding. Molecular dynamics (MD) and disulfide crosslinking studies suggest that apo-GCGR can adopt both an open and closed conformation associated with extensive contacts between the ECD and 7TM domain. The electron microscopy (EM) map of the full-length GCGR shows how a monoclonal antibody stabilizes the ECD and 7TM domain in an elongated conformation. Hydrogen/deuterium exchange (HDX) studies and MD simulations indicate that an open conformation is also stabilized by peptide ligand binding. The combined studies reveal the open/closed states of GCGR and suggest that glucagon binds to GCGR by a conformational selection mechanism.

  20. Probing of different conformations of piperazine using Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    SenGupta, Sumana; Maiti, Nandita; Chadha, Ridhima; Kapoor, Sudhir

    2014-06-01

    Piperazine exists in a number of energetically close structural conformations, and here, we investigated the dependence of their relative abundance on the surrounding conditions by using Raman and SERS spectroscopy in pure solid, aqueous solution and Ag hydrosol. The experimental results were interpreted by DFT calculations using B3LYP functional with aug-cc-pvdz/LANL2DZ basis sets. In the chair form of piperazine, which is more stable than the skewed boat by ∼8 kcal mol-1, the two N-H bonds can remain equatorial or axial, leading to three different conformations, eq-eq, eq-ax and ax-ax. The calculated Raman spectrum of the lowest energy eq-eq conformation corresponds well with the experimental spectrum in pure solid, indicating eq-eq to be predominant. But, the contribution of the eq-ax conformation was found to be maximum in aqueous solution. The SERS spectrum revealed that eq-ax conformation was preferably adopted as piperazine was adsorbed vertically through its axial N-atom over silver nanoparticle surface.

  1. Conformation and interactions of dopamine hydrochloride in solution

    SciTech Connect

    Callear, Samantha K.; Imberti, Silvia; Johnston, Andrew; McLain, Sylvia E.

    2015-01-07

    The aqueous solution of dopamine hydrochloride has been investigated using neutron and X-ray total scattering data together with Monte-Carlo based modelling using Empirical Potential Structure Refinement. The conformation of the protonated dopamine molecule is presented and the results compared to the conformations found in crystal structures, dopamine-complexed protein crystal structures and predicted from theoretical calculations and pharmacophoric models. It is found that protonated dopamine adopts a range of conformations in solution, highlighting the low rotational energy barrier between different conformations, with the preferred conformation being trans-perpendicular. The interactions between each of the species present (protonated dopamine molecules, water molecules, and chloride anions) have been determined and are discussed with reference to interactions observed in similar systems both in the liquid and crystalline state, and predicted from theoretical calculations. The expected strong hydrogen bonds between the strong hydrogen bond donors and acceptors are observed, together with evidence of weaker CH hydrogen bonds and π interactions also playing a significant role in determining the arrangement of adjacent molecules.

  2. Conformational states of the full-length glucagon receptor

    PubMed Central

    Yang, Linlin; Yang, Dehua; de Graaf, Chris; Moeller, Arne; West, Graham M.; Dharmarajan, Venkatasubramanian; Wang, Chong; Siu, Fai Y.; Song, Gaojie; Reedtz-Runge, Steffen; Pascal, Bruce D.; Wu, Beili; Potter, Clinton S.; Zhou, Hu; Griffin, Patrick R.; Carragher, Bridget; Yang, Huaiyu; Wang, Ming-Wei; Stevens, Raymond C.; Jiang, Hualiang

    2015-01-01

    Class B G protein-coupled receptors are composed of an extracellular domain (ECD) and a seven-transmembrane (7TM) domain, and their signalling is regulated by peptide hormones. Using a hybrid structural biology approach together with the ECD and 7TM domain crystal structures of the glucagon receptor (GCGR), we examine the relationship between full-length receptor conformation and peptide ligand binding. Molecular dynamics (MD) and disulfide crosslinking studies suggest that apo-GCGR can adopt both an open and closed conformation associated with extensive contacts between the ECD and 7TM domain. The electron microscopy (EM) map of the full-length GCGR shows how a monoclonal antibody stabilizes the ECD and 7TM domain in an elongated conformation. Hydrogen/deuterium exchange (HDX) studies and MD simulations indicate that an open conformation is also stabilized by peptide ligand binding. The combined studies reveal the open/closed states of GCGR and suggest that glucagon binds to GCGR by a conformational selection mechanism. PMID:26227798

  3. National Foster Care and Adoption Directory Search

    MedlinePlus

    ... Adoption Directory Search National Foster Care & Adoption Directory Search Many concerned individuals have expressed the desire to ... how to become a foster or adoptive parent. Search results for this category include contact information for: ...

  4. Logarithmic conformal field theory

    NASA Astrophysics Data System (ADS)

    Gainutdinov, Azat; Ridout, David; Runkel, Ingo

    2013-12-01

    Conformal field theory (CFT) has proven to be one of the richest and deepest subjects of modern theoretical and mathematical physics research, especially as regards statistical mechanics and string theory. It has also stimulated an enormous amount of activity in mathematics, shaping and building bridges between seemingly disparate fields through the study of vertex operator algebras, a (partial) axiomatisation of a chiral CFT. One can add to this that the successes of CFT, particularly when applied to statistical lattice models, have also served as an inspiration for mathematicians to develop entirely new fields: the Schramm-Loewner evolution and Smirnov's discrete complex analysis being notable examples. When the energy operator fails to be diagonalisable on the quantum state space, the CFT is said to be logarithmic. Consequently, a logarithmic CFT is one whose quantum space of states is constructed from a collection of representations which includes reducible but indecomposable ones. This qualifier arises because of the consequence that certain correlation functions will possess logarithmic singularities, something that contrasts with the familiar case of power law singularities. While such logarithmic singularities and reducible representations were noted by Rozansky and Saleur in their study of the U (1|1) Wess-Zumino-Witten model in 1992, the link between the non-diagonalisability of the energy operator and logarithmic singularities in correlators is usually ascribed to Gurarie's 1993 article (his paper also contains the first usage of the term 'logarithmic conformal field theory'). The class of CFTs that were under control at this time was quite small. In particular, an enormous amount of work from the statistical mechanics and string theory communities had produced a fairly detailed understanding of the (so-called) rational CFTs. However, physicists from both camps were well aware that applications from many diverse fields required significantly more

  5. Lattice Simulations and Infrared Conformality

    DOE PAGESBeta

    Appelquist, Thomas; Fleming, George T.; Lin, Meifeng; Neil, Ethan T.; Schaich, David A

    2011-09-01

    We examine several recent lattice-simulation data sets, asking whether they are consistent with infrared conformality. We observe, in particular, that for an SU(3) gauge theory with 12 Dirac fermions in the fundamental representation, recent simulation data can be described assuming infrared conformality. Lattice simulations include a fermion mass m which is then extrapolated to zero, and we note that this data can be fit by a small-m expansion, allowing a controlled extrapolation. We also note that the conformal hypothesis does not work well for two theories that are known or expected to be confining and chirally broken, and that itmore » does work well for another theory expected to be infrared conformal.« less

  6. Conformation Distributions in Adsorbed Proteins.

    NASA Astrophysics Data System (ADS)

    Meuse, Curtis W.; Hubbard, Joseph B.; Vrettos, John S.; Smith, Jackson R.; Cicerone, Marcus T.

    2007-03-01

    While the structural basis of protein function is well understood in the biopharmaceutical and biotechnology industries, few methods for the characterization and comparison of protein conformation distributions are available. New methods capable of measuring the stability of protein conformations and the integrity of protein-protein, protein-ligand and protein-surface interactions both in solution and on surfaces are needed to help the development of protein-based products. We are developing infrared spectroscopy methods for the characterization and comparison of molecular conformation distributions in monolayers and in solutions. We have extracted an order parameter describing the orientational and conformational variations of protein functional groups around the average molecular values from a single polarized spectrum. We will discuss the development of these methods and compare them to amide hydrogen/deuterium exchange methods for albumin in solution and on different polymer surfaces to show that our order parameter is related to protein stability.

  7. Lattice Simulations and Infrared Conformality

    SciTech Connect

    Appelquist, Thomas; Fleming, George T.; Lin, Meifeng; Neil, Ethan T.; Schaich, David A

    2011-09-01

    We examine several recent lattice-simulation data sets, asking whether they are consistent with infrared conformality. We observe, in particular, that for an SU(3) gauge theory with 12 Dirac fermions in the fundamental representation, recent simulation data can be described assuming infrared conformality. Lattice simulations include a fermion mass m which is then extrapolated to zero, and we note that this data can be fit by a small-m expansion, allowing a controlled extrapolation. We also note that the conformal hypothesis does not work well for two theories that are known or expected to be confining and chirally broken, and that it does work well for another theory expected to be infrared conformal.

  8. 29 CFR 500.105 - DOT standards adopted by the Secretary.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the purposes of this section has adopted from 49 CFR part 398 the following pertinent standards. (In... conform the language to these regulations): (1) Qualification of drivers or operators (Source: 49 CFR 398...) Driving of motor vehicles (Source: 49 CFR 398.4)—(i) Compliance required. Every person shall comply...

  9. 29 CFR 500.105 - DOT standards adopted by the Secretary.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the purposes of this section has adopted from 49 CFR part 398 the following pertinent standards. (In... conform the language to these regulations): (1) Qualification of drivers or operators (Source: 49 CFR 398...) Driving of motor vehicles (Source: 49 CFR 398.4)—(i) Compliance required. Every person shall comply...

  10. 29 CFR 500.105 - DOT standards adopted by the Secretary.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the purposes of this section has adopted from 49 CFR part 398 the following pertinent standards. (In... conform the language to these regulations): (1) Qualification of drivers or operators (Source: 49 CFR 398...) Driving of motor vehicles (Source: 49 CFR 398.4)—(i) Compliance required. Every person shall comply...

  11. 29 CFR 500.105 - DOT standards adopted by the Secretary.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the purposes of this section has adopted from 49 CFR part 398 the following pertinent standards. (In... conform the language to these regulations): (1) Qualification of drivers or operators (Source: 49 CFR 398...) Driving of motor vehicles (Source: 49 CFR 398.4)—(i) Compliance required. Every person shall comply...

  12. 29 CFR 500.105 - DOT standards adopted by the Secretary.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the purposes of this section has adopted from 49 CFR part 398 the following pertinent standards. (In... conform the language to these regulations): (1) Qualification of drivers or operators (Source: 49 CFR 398...) Driving of motor vehicles (Source: 49 CFR 398.4)—(i) Compliance required. Every person shall comply...

  13. CONFORMANCE IMPROVEMENT USING GELS

    SciTech Connect

    Randall S. Seright

    2004-03-01

    This technical progress report describes work performed from September 1, 2003, through February 29, 2004, for the project, ''Conformance Improvement Using Gels.'' We examined the properties of several ''partially formed'' gels that were formulated with a combination of high and low molecular weight HPAM polymers. After placement in 4-mm-wide fractures, these gels required about 25 psi/ft for brine to breach the gel (the best performance to date in fractures this wide). After this breach, stabilized residual resistance factors decreased significantly with increased flow rate. Also, residual resistance factors were up to 9 times greater for water than for oil. Nevertheless, permeability reduction factors were substantial for both water and oil flow. Gel with 2.5% chopped fiberglass effectively plugged 4-mm-wide fractures if a 0.5-mm-wide constriction was present. The ability to screen-out at a constriction appears crucial for particulate incorporation to be useful in plugging fractures. In addition to fiberglass, we examined incorporation of polypropylene fibers into gels. Once dispersed in brine or gelant, the polypropylene fibers exhibited the least gravity segregation of any particulate that we have tested to date. In fractures with widths of at least 2 mm, 24-hr-old gels (0.5% high molecular weight HPAM) with 0.5% fiber did not exhibit progressive plugging during placement and showed extrusion pressure gradients similar to those of gels without the fiber. The presence of the fiber roughly doubled the gel's resistance to first breach by brine flow. The breaching pressure gradients were not as large as for gels made with high and low molecular weight polymers (mentioned above). However, their material requirements and costs (i.e., polymer and/or particulate concentrations) were substantially lower than for those gels. A partially formed gel made with 0.5% HPAM did not enter a 0.052-mm-wide fracture when applying a pressure gradient of 65 psi/ft. This result

  14. CONFORMANCE IMPROVEMENT USING GELS

    SciTech Connect

    Randall S. Seright

    2004-09-30

    This report describes work performed during the third and final year of the project, ''Conformance Improvement Using Gels.'' Corefloods revealed throughput dependencies of permeability reduction by polymers and gels that were much more prolonged during oil flow than water flow. This behavior was explained using simple mobility ratio arguments. A model was developed that quantitatively fits the results and predicts ''clean up'' times for oil productivity when production wells are returned to service after application of a polymer or gel treatment. X-ray computed microtomography studies of gels in strongly water-wet Berea sandstone and strongly oil-wet porous polyethylene suggested that oil penetration through gel-filled pores occurs by a gel-dehydration mechanism, rather than gel-ripping or gel-displacement mechanisms. In contrast, analysis of data from the University of Kansas suggests that the gel-ripping or displacement mechanisms are more important in more permeable, strongly water-wet sandpacks. These findings help to explain why aqueous gels can reduce permeability to water more than to oil under different conditions. Since cement is the most commonly used material for water shutoff, we considered when gels are preferred over cements. Our analysis and experimental results indicated that cement cannot be expected to completely fill (top to bottom) a vertical fracture of any width, except near the wellbore. For vertical fractures with apertures less than 4 mm, the cement slurry will simply not penetrate very far into the fracture. For vertical fractures with apertures greater than 4 mm, the slurry may penetrate a substantial distance into the bottom part of the fracture. However, except near the wellbore, the upper part of the fracture will remain open due to gravity segregation. We compared various approaches to plugging fractures using gels, including (1) varying polymer content, (2) varying placement (extrusion) rate, (3) using partially formed gels, (4

  15. The Texas Adoption Project: Adopted Children and Their Intellectual Resemblance to Biological and Adoptive Parents.

    ERIC Educational Resources Information Center

    Horn, Joseph M.

    1983-01-01

    Intelligence test scores were obtained from parents and children in 300 adoptive families and compared with similar data available from the children's biological mothers. Results support the hypothesis that genetic variability is an important influence in the development of individual differences in intelligence. (Author/RH)

  16. Dynamic clustering threshold reduces conformer ensemble size while maintaining a biologically relevant ensemble.

    PubMed

    Yongye, Austin B; Bender, Andreas; Martínez-Mayorga, Karina

    2010-08-01

    Representing the 3D structures of ligands in virtual screenings via multi-conformer ensembles can be computationally intensive, especially for compounds with a large number of rotatable bonds. Thus, reducing the size of multi-conformer databases and the number of query conformers, while simultaneously reproducing the bioactive conformer with good accuracy, is of crucial interest. While clustering and RMSD filtering methods are employed in existing conformer generators, the novelty of this work is the inclusion of a clustering scheme (NMRCLUST) that does not require a user-defined cut-off value. This algorithm simultaneously optimizes the number and the average spread of the clusters. Here we describe and test four inter-dependent approaches for selecting computer-generated conformers, namely: OMEGA, NMRCLUST, RMS filtering and averaged-RMS filtering. The bioactive conformations of 65 selected ligands were extracted from the corresponding protein:ligand complexes from the Protein Data Bank, including eight ligands that adopted dissimilar bound conformations within different receptors. We show that NMRCLUST can be employed to further filter OMEGA-generated conformers while maintaining biological relevance of the ensemble. It was observed that NMRCLUST (containing on average 10 times fewer conformers per compound) performed nearly as well as OMEGA, and both outperformed RMS filtering and averaged-RMS filtering in terms of identifying the bioactive conformations with excellent and good matches (0.5 < RMSD < 1.0 A). Furthermore, we propose thresholds for OMEGA root-mean square filtering depending on the number of rotors in a compound: 0.8, 1.0 and 1.4 for structures with low (1-4), medium (5-9) and high (10-15) numbers of rotatable bonds, respectively. The protocol employed is general and can be applied to reduce the number of conformers in multi-conformer compound collections and alleviate the complexity of downstream data processing in virtual screening experiments

  17. Delineating the conformational flexibility of trisaccharides from NMR spectroscopy experiments and computer simulations.

    PubMed

    Yang, Mingjun; Angles d'Ortoli, Thibault; Säwén, Elin; Jana, Madhurima; Widmalm, Göran; MacKerell, Alexander D

    2016-07-28

    The conformation of saccharides in solution is challenging to characterize in the context of a single well-defined three-dimensional structure. Instead, they are better represented by an ensemble of conformations associated with their structural diversity and flexibility. In this study, we delineate the conformational heterogeneity of five trisaccharides via a combination of experimental and computational techniques. Experimental NMR measurements target conformationally sensitive parameters, including J couplings and effective distances around the glycosidic linkages, while the computational simulations apply the well-calibrated additive CHARMM carbohydrate force field in combination with efficient enhanced sampling molecular dynamics simulation methods. Analysis of conformational heterogeneity is performed based on sampling of discreet states as defined by dihedral angles, on root-mean-square differences of Cartesian coordinates and on the extent of volume sampled. Conformational clustering, based on the glycosidic linkage dihedral angles, shows that accounting for the full range of sampled conformations is required to reproduce the experimental data, emphasizing the utility of the molecular simulations in obtaining an atomic detailed description of the conformational properties of the saccharides. Results show the presence of differential conformational preferences as a function of primary sequence and glycosidic linkage types. Significant differences in conformational ensembles associated with the anomeric configuration of a single glycosidic linkage reinforce the impact of such changes on the conformational properties of carbohydrates. The present structural insights of the studied trisaccharides represent a foundation for understanding the range of conformations adopted in larger oligosaccharides and how these molecules encode their conformational heterogeneity into the monosaccharide sequence. PMID:27346493

  18. Protein Allostery and Conformational Dynamics.

    PubMed

    Guo, Jingjing; Zhou, Huan-Xiang

    2016-06-01

    The functions of many proteins are regulated through allostery, whereby effector binding at a distal site changes the functional activity (e.g., substrate binding affinity or catalytic efficiency) at the active site. Most allosteric studies have focused on thermodynamic properties, in particular, substrate binding affinity. Changes in substrate binding affinity by allosteric effectors have generally been thought to be mediated by conformational transitions of the proteins or, alternatively, by changes in the broadness of the free energy basin of the protein conformational state without shifting the basin minimum position. When effector binding changes the free energy landscape of a protein in conformational space, the change affects not only thermodynamic properties but also dynamic properties, including the amplitudes of motions on different time scales and rates of conformational transitions. Here we assess the roles of conformational dynamics in allosteric regulation. Two cases are highlighted where NMR spectroscopy and molecular dynamics simulation have been used as complementary approaches to identify residues possibly involved in allosteric communication. Perspectives on contentious issues, for example, the relationship between picosecond-nanosecond local and microsecond-millisecond conformational exchange dynamics, are presented. PMID:26876046

  19. Embryo adoption: Some further considerations.

    PubMed

    Patterson, Colin

    2015-02-01

    Recent discussions of embryo adoption have sought to make sense of the teaching of the Congregation for the Doctrine of the Faith (CDF) document Dignitas personae which appeared to provide a negative judgment on such a practice. This article aims to provide a personalist account of the process of fertilization and implantation that might serve as the basis for the negative judgment of the CDF document. In doing so, it relies upon the idea that a person, including an embryo, is not to be considered in isolation, but always in relation to God and to others. This approach extends the substantialist conceptualizations commonly employed in discussions of this issue. More generally, the article seeks to highlight the value of a personalist re-framing for an understanding of the moral questions surrounding the beginning of life. Lay summary: This article seeks to make sense of what appears to be a clear-cut rejection, set out in the Congregation for the Doctrine of the Faith (CDF) document Dignitas personae, of the proposal for women to "adopt" surplus frozen embryos. It draws upon more recently developed modes of philosophical/theological reasoning to argue that, in human procreation, both fertilization and implantation represent constitutive dimensions of divine creative activity and so must be protected from manipulative technological intervention. Since embryo adoption requires this kind of technology, it makes sense for the Church document not to approve it. PMID:25698841

  20. Linkage-specific conformational ensembles of non-canonical polyubiquitin chains.

    PubMed

    Castañeda, Carlos A; Chaturvedi, Apurva; Camara, Christina M; Curtis, Joseph E; Krueger, Susan; Fushman, David

    2016-02-17

    Polyubiquitination is a critical protein post-translational modification involved in a variety of processes in eukaryotic cells. The molecular basis for selective recognition of the polyubiquitin signals by cellular receptors is determined by the conformations polyubiquitin chains adopt; this has been demonstrated for K48- and K63-linked chains. Recent studies of the so-called non-canonical chains (linked via K6, K11, K27, K29, or K33) suggest they play important regulatory roles in growth, development, and immune system pathways, but biophysical studies are needed to elucidate the physical/structural basis of their interactions with receptors. A first step towards this goal is characterization of the conformations these chains adopt in solution. We assembled diubiquitins (Ub2) comprised of every lysine linkage. Using solution NMR measurements, small-angle neutron scattering (SANS), and in silico ensemble generation, we determined population-weighted conformational ensembles that shed light on the structure and dynamics of the non-canonical polyubiquitin chains. We found that polyubiquitin is conformationally heterogeneous, and each chain type exhibits unique conformational ensembles. For example, K6-Ub2 and K11-Ub2 (at physiological salt concentration) are in dynamic equilibrium between at least two conformers, where one exhibits a unique Ub/Ub interface, distinct from that observed in K48-Ub2 but similar to crystal structures of these chains. Conformers for K29-Ub2 and K33-Ub2 resemble recent crystal structures in the ligand-bound state. Remarkably, a number of diubiquitins adopt conformers similar to K48-Ub2 or K63-Ub2, suggesting potential overlap of biological function among different lysine linkages. These studies highlight the potential power of determining function from elucidation of conformational states. PMID:26422168

  1. CONFORMANCE IMPROVEMENT USING GELS

    SciTech Connect

    Randall S. Seright

    2003-09-01

    This report describes work performed during the second year of the project, ''Conformance Improvement Using Gels.'' The project has two objectives. The first objective is to identify gel compositions and conditions that substantially reduce flow through fractures that allow direct channeling between wells, while leaving secondary fractures open so that high fluid injection and production rates can be maintained. The second objective is to optimize treatments in fractured production wells, where the gel must reduce permeability to water much more than that to oil. Pore-level images from X-ray computed microtomography were re-examined for Berea sandstone and porous polyethylene. This analysis suggests that oil penetration through gel-filled pores occurs by a gel-dehydration mechanism, rather than a gel-ripping mechanism. This finding helps to explain why aqueous gels can reduce permeability to water more than to oil. We analyzed a Cr(III)-acetate-HPAM gel treatment in a production well in the Arbuckle formation. The availability of accurate pressure data before, during, and after the treatment was critical for the analysis. After the gel treatment, water productivity was fairly constant at about 20% of the pre-treatment value. However, oil productivity was stimulated by a factor of 18 immediately after the treatment. During the six months after the treatment, oil productivity gradually decreased to approach the pre-treatment value. To explain this behavior, we proposed that the fracture area open to oil flow was increased substantially by the gel treatment, followed by a gradual closing of the fractures during subsequent production. For a conventional Cr(III)-acetate-HPAM gel, the delay between gelant preparation and injection into a fracture impacts the placement, leakoff, and permeability reduction behavior. Formulations placed as partially formed gels showed relatively low pressure gradients during placement, and yet substantially reduced the flow capacity of

  2. SERCA mutant E309Q binds two Ca2+ ions but adopts a catalytically incompetent conformation

    PubMed Central

    Clausen, Johannes D; Bublitz, Maike; Arnou, Bertrand; Montigny, Cédric; Jaxel, Christine; Møller, Jesper Vuust; Nissen, Poul; Andersen, Jens Peter; le Maire, Marc

    2013-01-01

    The sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) couples ATP hydrolysis to transport of Ca2+. This directed energy transfer requires cross-talk between the two Ca2+ sites and the phosphorylation site over 50 Å distance. We have addressed the mechano-structural basis for this intramolecular signal by analysing the structure and the functional properties of SERCA mutant E309Q. Glu309 contributes to Ca2+ coordination at site II, and a consensus has been that E309Q only binds Ca2+ at site I. The crystal structure of E309Q in the presence of Ca2+ and an ATP analogue, however, reveals two occupied Ca2+ sites of a non-catalytic Ca2E1 state. Ca2+ is bound with micromolar affinity by both Ca2+ sites in E309Q, but without cooperativity. The Ca2+-bound mutant does phosphorylate from ATP, but at a very low maximal rate. Phosphorylation depends on the correct positioning of the A-domain, requiring a shift of transmembrane segment M1 into an ‘up and kinked position'. This transition is impaired in the E309Q mutant, most likely due to a lack of charge neutralization and altered hydrogen binding capacities at Ca2+ site II. PMID:24270570

  3. p97 Disease Mutations Modulate Nucleotide-Induced Conformation to Alter Protein-Protein Interactions.

    PubMed

    Bulfer, Stacie L; Chou, Tsui-Fen; Arkin, Michelle R

    2016-08-19

    The AAA+ ATPase p97/VCP adopts at least three conformations that depend on the binding of ADP and ATP and alter the orientation of the N-terminal protein-protein interaction (PPI) domain into "up" and "down" conformations. Point mutations that cause multisystem proteinopathy 1 (MSP1) are found at the interface of the N domain and D1-ATPase domain and potentially alter the conformational preferences of p97. Additionally, binding of "adaptor" proteins to the N-domain regulates p97's catalytic activity. We propose that p97/adaptor PPIs are coupled to p97 conformational states. We evaluated the binding of nucleotides and the adaptor proteins p37 and p47 to wild-type p97 and MSP1 mutants. Notably, p47 and p37 bind 8-fold more weakly to the ADP-bound conformation of wild-type p97 compared to the ATP-bound conformation. However, MSP1 mutants lose this nucleotide-induced conformational coupling because they destabilize the ADP-bound, "down" conformation of the N-domain. Loss in conformation coupling to PPIs could contribute to the mechanism of MSP1. PMID:27267671

  4. To Conform or Not to Conform: Spontaneous Conformity Diminishes the Sensitivity to Monetary Outcomes

    PubMed Central

    2013-01-01

    When people have different opinions in a group, they often adjust their own attitudes and behaviors to match the group opinion, known as social conformity. The affiliation account of normative conformity states that people conform to norms in order to ‘fit in’, whereas the accuracy account of informative conformity posits that the motive to learn from others produces herding. Here, we test another possibility that following the crowd reduces the experienced negative emotion when the group decision turns out to be a bad one. Using event related potential (ERP) combined with a novel group gambling task, we found that participants were more likely to choose the option that was predominately chosen by other players in previous trials, although there was little explicit normative pressure at the decision stage and group choices were not informative. When individuals' choices were different from others, the feedback related negativity (FRN), an ERP component sensitive to losses and errors, was enhanced, suggesting that being independent is aversive. At the outcome stage, the losses minus wins FRN effect was significantly reduced following conformity choices than following independent choices. Analyses of the P300 revealed similar patterns both in the response and outcome period. Our study suggests that social conformity serves as an emotional buffer that protects individuals from experiencing strong negative emotion when the outcomes are bad. PMID:23691242

  5. 18 CFR 341.6 - Adoption rule.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Adoption rule. 341.6... SUBJECT TO SECTION 6 OF THE INTERSTATE COMMERCE ACT § 341.6 Adoption rule. (a) Change in name of carrier... such occurrence. The filing of adoption notices and adoption supplements requires no notice period....

  6. 33 CFR 230.21 - Adoption.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... FOR IMPLEMENTING NEPA § 230.21 Adoption. See 40 CFR 1506.3. A district commander will normally adopt... recirculated as provided in 40 CFR 1506.3 (b) or (c), the adopted EIS with the supplement, if any, will be... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Adoption. 230.21 Section...

  7. 33 CFR 230.21 - Adoption.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... FOR IMPLEMENTING NEPA § 230.21 Adoption. See 40 CFR 1506.3. A district commander will normally adopt... recirculated as provided in 40 CFR 1506.3 (b) or (c), the adopted EIS with the supplement, if any, will be... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Adoption. 230.21 Section...

  8. 18 CFR 341.6 - Adoption rule.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Adoption rule. 341.6... SUBJECT TO SECTION 6 OF THE INTERSTATE COMMERCE ACT § 341.6 Adoption rule. (a) Change in name of carrier... such occurrence. The filing of adoption notices and adoption supplements requires no notice period....

  9. 33 CFR 230.21 - Adoption.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... FOR IMPLEMENTING NEPA § 230.21 Adoption. See 40 CFR 1506.3. A district commander will normally adopt... recirculated as provided in 40 CFR 1506.3 (b) or (c), the adopted EIS with the supplement, if any, will be... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Adoption. 230.21 Section...

  10. 18 CFR 341.6 - Adoption rule.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Adoption rule. 341.6... SUBJECT TO SECTION 6 OF THE INTERSTATE COMMERCE ACT § 341.6 Adoption rule. (a) Change in name of carrier... such occurrence. The filing of adoption notices and adoption supplements requires no notice period....

  11. 33 CFR 230.21 - Adoption.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... FOR IMPLEMENTING NEPA § 230.21 Adoption. See 40 CFR 1506.3. A district commander will normally adopt... recirculated as provided in 40 CFR 1506.3 (b) or (c), the adopted EIS with the supplement, if any, will be... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Adoption. 230.21 Section...

  12. 18 CFR 341.6 - Adoption rule.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Adoption rule. 341.6... SUBJECT TO SECTION 6 OF THE INTERSTATE COMMERCE ACT § 341.6 Adoption rule. (a) Change in name of carrier... such occurrence. The filing of adoption notices and adoption supplements requires no notice period....

  13. 33 CFR 230.21 - Adoption.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... FOR IMPLEMENTING NEPA § 230.21 Adoption. See 40 CFR 1506.3. A district commander will normally adopt... recirculated as provided in 40 CFR 1506.3 (b) or (c), the adopted EIS with the supplement, if any, will be... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Adoption. 230.21 Section...

  14. Experiences of Black Families as Adoptive Parents.

    ERIC Educational Resources Information Center

    Prater, Gwendolyn S.; King, Lula T.

    1988-01-01

    Conducted descriptive study in which 12 Black families shared their ideas about adoptive parenthood. Found most common reason for adopting was inability to have children biologically. Found need for post-adoptive services for Black families on an as-needed basis. Recommends adoption agencies and communities build on positive experiences of Black…

  15. Policy Issues in Gay and Lesbian Adoption.

    ERIC Educational Resources Information Center

    Sullivan, Ann

    1995-01-01

    Notes that adoption agencies have developed few specific policies on the issue of lesbian and gay adoption. Provides an overview of key considerations about homosexual adopters, including beliefs and values of agency professionals, the legal and social ramifications of adoption into a relationship not based on marriage, and possible consequences…

  16. Adoption and Single Parents: A Review.

    ERIC Educational Resources Information Center

    Groze, Vic

    1991-01-01

    Examines the literature about people who choose to become single adoptive parents. Reviews the demographic and personal characteristics of single parents who adopt, and summarizes the experiences of single parents with the children they adopt. Calls for further research on single parents who adopt special needs children. (GH)

  17. Adoption: Pediatric, Legislative and Social Issues

    PubMed Central

    Davis, Joseph H.; Brown, Dirck W.

    1981-01-01

    Physicians may find themselves involved in many phases of the adoption process, ranging from advising infertile couples who wish to adopt a child to caring for adopted children, adolescents or adults. Recent legislation has been aimed at making it possible for children to be adopted who have been receiving foster care and at providing financial assistance to implement the adoption of children with handicaps and with medical problems. The adoption process is becoming more open. Adoptees are searching for and finding their biological parents and all parties in the “adoption triangle” are developing relationships with one another. PMID:7257384

  18. The principle of conformational signaling.

    PubMed

    Tompa, Peter

    2016-07-25

    Signal transduction is the primary process by which cells respond to changes in their physical and chemical environments. Cellular response is initiated through a signaling protein (a receptor), which interacts with the "signal", most often a novel molecule outside or inside the cell. The mechanism of activation of the receptor is a conformational change and/or covalent modification, which then sets in motion a signaling pathway, i.e. a cascade of modification and binding events that relay and amplify the message to eventually alter the state of the cell. In reflection of this general perception, concepts such as the "second messenger" and the "phosphorylation cascade" dominate our views of signal transduction. The idea I advocate here is that the non-covalent change in protein conformation itself might serve as the initial or intermittent "signal" in the cascade, and it is often the primary event being recognized and interpreted by downstream receptor(s). This signaling principle is intertwined with many other cellular regulatory concepts, such as (pathway) allostery, conformational spread, induced folding/unfolding, conformational memory, the hierarchical assembly of complexes, and the action of regulatory chaperones and prions. By elaborating on many examples and also recent advances in experimental methodology, I show that conformational signaling, although thus far underappreciated, is a general and robust signaling principle that most of the time operates in close interplay with covalent signals in the cell. PMID:27242242

  19. Adoptive cell therapy for sarcoma

    PubMed Central

    Mata, Melinda; Gottschalk, Stephen

    2015-01-01

    Current therapy for sarcomas, though effective in treating local disease, is often ineffective for patients with recurrent or metastatic disease. To improve outcomes, novel approaches are needed and cell therapy has the potential to meet this need since it does not rely on the cytotoxic mechanisms of conventional therapies. The recent successes of T-cell therapies for hematological malignancies have led to renewed interest in exploring cell therapies for solid tumors such as sarcomas. In this review, we will discuss current cell therapies for sarcoma with special emphasis on genetic approaches to improve the effector function of adoptively transferred cells. PMID:25572477

  20. Council Adopts Two Major Statements

    NASA Astrophysics Data System (ADS)

    2005-06-01

    On 27 May, the AGU Council approved an update to the Union's vision statement and adopted a position statement concerning the U.S. plans for a Moon-Mars initiative. The vision statement, which is reproduced in this section of Eos, describes what the AGU is expected to look like 10 years in the future. The Planning Committee, under the chairmanship of President-elect Tim Killeen, and with input from the policy committees, Sections, and Focus Groups, is updating AGU's strategic plan, which is intended to move measurably toward the vision.

  1. Bridging the Divide: Openness in Adoption and Post-adoption Psychosocial Adjustment among Birth and Adoptive Parents

    PubMed Central

    Ge, Xiaojia; Natsuaki, Misaki N.; Martin, David; Leve, Leslie; Neiderhiser, Jenae; Shaw, Daniel S.; Villareal, Georgette; Scaramella, Laura; Reid, John; Reiss, David

    2008-01-01

    Using 323 matched parties of birth mothers and adoptive parents, this study examined the association between the degree of adoption openness (e.g., contact and knowledge between parties) and birth and adoptive parents’ post-adoption adjustment shortly after the adoption placement (6 to 9 months). Data from birth fathers (N=112), an understudied sample, also were explored. Openness was assessed by multiple informants. Results indicated that openness was significantly related to satisfaction with adoption process among adoptive parents and birth mothers. Increased openness was positively associated with birth mothers’ post-placement adjustment as indexed by birth mothers’ self reports and the interviewers’ impression of birth mothers’ adjustment. Birth fathers’ report of openness was associated with their greater satisfaction with the adoption process and better post-adoption adjustment. PMID:18729667

  2. Specific Conformational States of Ras GTPase upon Effector Binding

    PubMed Central

    2012-01-01

    To uncover the structural and dynamical determinants involved in the highly specific binding of Ras GTPase to its effectors, the conformational states of Ras in uncomplexed form and complexed to the downstream effectors Byr2, PI3Kγ, PLCε, and RalGDS were investigated using molecular dynamics and cross-comparison of the trajectories. The subtle changes in the dynamics and conformations of Ras upon effector binding require an analysis that targets local changes independent of global motions. Using a structural alphabet, a computational procedure is proposed to quantify local conformational changes. Positions detected by this approach were characterized as either specific for a particular effector, specific for an effector domain type, or as effector unspecific. A set of nine structurally connected residues (Ras residues 5–8, 32–35, 39–42, 55–59, 73–78, and 161–165), which link the effector binding site to the distant C-terminus, changed dynamics upon effector binding, indicating a potential effector-unspecific signaling route within the Ras structure. Additional conformational changes were detected along the N-terminus of the central β-sheet. Besides the Ras residues at the effector interface (e.g., D33, E37, D38, and Y40), which adopt effector-specific local conformations, the binding signal propagates from the interface to distant hot-spot residues, in particular to Y5 and D57. The results of this study reveal possible conformational mechanisms for the stabilization of the active state of Ras upon downstream effector binding and for the structural determinants responsible for effector specificity. PMID:23316125

  3. Cholest-5-en-3β-yl 3-(4-eth­oxy­phen­yl)prop-2-enoate

    PubMed Central

    Bugenhagen, Bernhard; Munk, Ariane; Vill, Volkmar; Al-Jasem, Yosef; Thiemann, Thies

    2012-01-01

    In the asymmetric unit of the title compound, C38H56O3, there are two symmetry-independent mol­ecules that differ in the rotation angle along the C—O bond between the 3-(4-eth­oxy­phen­yl)prop-2-enoate and cholest-5-en-3β-yl groups by 169.3 (3)°. In both mol­ecules, steroid ring B adopts a half-chair conformation, rings A and C adopt a chair conformation and ring D exists in an envelope form. The two symmetry-independent mol­ecules pack in the crystal into separate layers parallel to (-102) with their long axis parallel to the [201] direction. Short inter­molecular C—H⋯O and C—H⋯π contacts are observed. PMID:22807885

  4. L-prolinium picrate and 2-methylpyridinium picrate.

    PubMed

    Anitha, K; Athimoolam, S; Natarajan, S

    2006-09-01

    In the structure of L-prolinium picrate, C5H10NO2+.C6H2N3O7-, the Cgamma atom of the pyrrolidine ring has conformational disorder. Both the major and minor conformers of the pyrrolidine ring adopt conformations intermediate between a half-chair and an envelope. Both the cation and anion are packed through chelated three-centred N-H...O hydrogen bonds. The prolinium cation connects two different picrate anions, leading to an infinite chain running along the b axis. In 2-methylpyridinium picrate, C6H8N+.C6H2N3O7-, the cations and anions are packed separately along the a axis and are interconnected by N-H...O hydrogen bonds. Intramolecular contacts between phenolate O atoms and adjacent nitro groups are identified in both structures. A graph-set motif of R1(2)(6) is observed in both structures. PMID:16954644

  5. Adoptive T-cell therapy.

    PubMed

    Lokhorst, H M; Liebowitz, D

    1999-01-01

    Adoptive immunotherapy, or the transfer of immunocompetent cells, has been shown to be a promising new strategy for treatment of a variety of malignancies, including leukemia and non-Hodgkin's lymphoma. The possibility that it may likewise benefit patients with multiple myeloma is now being explored by researchers in Europe and the United States. Two alternatives, one using donor leukocyte infusions (DLIs) and the other using autologous T cells, are described. In the Netherlands, researchers studied the use of DLIs in 17 patients with multiple myeloma who relapsed after bone marrow transplant (BMT). Of 16 evaluable patients, 10 (62%) responded, with six (37%) achieving a complete response (CR). After a median follow-up duration of 28 months, five patients relapsed and five remained in remission. Graft-versus-host disease (GVHD) developed in nine patients. In the United States, adoptive immunotherapy is currently being tested in eight patients with chemotherapy-resistant lymphoma. Autologous T cells were obtained prior to BMT and expanded using an anti-CD3/CD28 culture system. After BMT, the cells were reinfused into the patient. At approximately day 14, granulocyte levels began to recover in the six evaluable patients, and levels remained relatively stable over the posttreatment course. Two patients developed severe autoimmune toxicity, which responded to treatment in one and resolved spontaneously in the other. PMID:9989486

  6. Embryo adoption: Some further considerations

    PubMed Central

    Patterson, Colin

    2015-01-01

    Recent discussions of embryo adoption have sought to make sense of the teaching of the Congregation for the Doctrine of the Faith (CDF) document Dignitas personae which appeared to provide a negative judgment on such a practice. This article aims to provide a personalist account of the process of fertilization and implantation that might serve as the basis for the negative judgment of the CDF document. In doing so, it relies upon the idea that a person, including an embryo, is not to be considered in isolation, but always in relation to God and to others. This approach extends the substantialist conceptualizations commonly employed in discussions of this issue. More generally, the article seeks to highlight the value of a personalist re-framing for an understanding of the moral questions surrounding the beginning of life. Lay summary: This article seeks to make sense of what appears to be a clear-cut rejection, set out in the Congregation for the Doctrine of the Faith (CDF) document Dignitas personae, of the proposal for women to “adopt” surplus frozen embryos. It draws upon more recently developed modes of philosophical/theological reasoning to argue that, in human procreation, both fertilization and implantation represent constitutive dimensions of divine creative activity and so must be protected from manipulative technological intervention. Since embryo adoption requires this kind of technology, it makes sense for the Church document not to approve it. PMID:25698841

  7. Proline-glutamate chimera's side chain conformation directs the type of β-hairpin structure.

    PubMed

    Maity, Jyotirmoy; Gerling, Ulla I M; Vukelić, Stella; Schäfer, Andreas; Koksch, Beate

    2014-01-01

    Our aim was to study the impact of two proline chimeras, containing a glutamic acid side chain in cis- or trans-configuration, on secondary structure formation. We further investigated to what extent the configuration of the side chain contributes to the overall peptide conformation. We used a 10 residue peptide (IYSNPDGTWT) that forms a β-hairpin in water. The turn-forming proline was substituted with either a cis- or trans-proline-glutamic acid chimera, resulting in the peptides IYSNPcis -E DGTWT (P1_Pcis-E) and IYSNP(trans-E)DGTWT (P1_Ptrans-E). We studied the conformation of the modified peptides by circular dichroism (CD) and NMR-spectroscopy, and SEC/static light scattering (SLS) analysis. NMR analysis reveals that the modified peptides maintain the β-hairpin conformation in aqueous solution. At 5 °C and pH 4.3, the peptide (P1_Pcis-E) was found to adopt two coexisting β-hairpin conformations (2:2 β-hairpin, and 3:5 β-hairpin). In contrast to that, the peptide (P1_Ptrans-E) adopts a 2:2 β-hairpin that exists in equilibrium with a 4:4 β-hairpin conformation. The adoption of ordered β-hairpin structures for both modified peptides could be confirmed by CD spectroscopy, while SEC/SLS analysis showed a monomeric oligomerization state for all three investigated peptides. With the combination of several NMR methods, we were able to elucidate that even small alterations in the side chain conformation of the proline-glutamate chimera (cis or trans) can significantly influence the conformation of the adopted β-hairpin. PMID:24221353

  8. Nonlocal gravity: Conformally flat spacetimes

    NASA Astrophysics Data System (ADS)

    Bini, Donato; Mashhoon, Bahram

    2016-04-01

    The field equations of the recent nonlocal generalization of Einstein’s theory of gravitation are presented in a form that is reminiscent of general relativity. The implications of the nonlocal field equations are studied in the case of conformally flat spacetimes. Even in this simple case, the field equations are intractable. Therefore, to gain insight into the nature of these equations, we investigate the structure of nonlocal gravity (NLG) in 2D spacetimes. While any smooth 2D spacetime is conformally flat and satisfies Einstein’s field equations, only a subset containing either a Killing vector or a homothetic Killing vector can satisfy the field equations of NLG.

  9. Conformational dynamics through an intermediate

    NASA Astrophysics Data System (ADS)

    Garai, Ashok; Zhang, Yaojun; Dudko, Olga K.

    2014-04-01

    The self-assembly of biological and synthetic nanostructures commonly proceeds via intermediate states. In living systems in particular, the intermediates have the capacity to tilt the balance between functional and potentially fatal behavior. This work develops a statistical mechanical treatment of conformational dynamics through an intermediate under a variable force. An analytical solution is derived for the key experimentally measurable quantity—the distribution of forces at which a conformational transition occurs. The solution reveals rich kinetics over a broad range of parameters and enables one to locate the intermediate and extract the activation barriers and rate constants.

  10. Asymmetric conformational maturation of HIV-1 reverse transcriptase

    PubMed Central

    Zheng, Xunhai; Perera, Lalith; Mueller, Geoffrey A; DeRose, Eugene F; London, Robert E

    2015-01-01

    HIV-1 reverse transcriptase utilizes a metamorphic polymerase domain that is able to adopt two alternate structures that fulfill catalytic and structural roles, thereby minimizing its coding requirements. This ambiguity introduces folding challenges that are met by a complex maturation process. We have investigated this conformational maturation using NMR studies of methyl-labeled RT for the slower processes in combination with molecular dynamics simulations for rapid processes. Starting from an inactive conformation, the p66 precursor undergoes a unimolecular isomerization to a structure similar to its active form, exposing a large hydrophobic surface that facilitates initial homodimer formation. The resulting p66/p66' homodimer exists as a conformational heterodimer, after which a series of conformational adjustments on different time scales can be observed. Formation of the inter-subunit RH:thumb' interface occurs at an early stage, while maturation of the connection' and unfolding of the RH' domains are linked and occur on a much slower time scale. DOI: http://dx.doi.org/10.7554/eLife.06359.001 PMID:26037594

  11. Chain conformational and physicochemical properties of fucoidans from sea cucumber.

    PubMed

    Xu, Xiaoqi; Xue, Changhu; Chang, Yaoguang; Wang, Jun; Jiang, Kunhao

    2016-11-01

    Although fucoidans from sea cucumber (SC-FUCs) have been proven as potential bioactive polysaccharides and functional food ingridents, their chain conformation and physicochemical properties were still poorly understood. This study investigated the chain conformation of fucoidans from sea cucumber Acaudina molpadioides (Am-FUC), Isostichopus badionotus (Ib-FUC) and Apostichopus japonicus (Aj-FUC), of which primary structure has been recently clarified. Chain conformation parameters demonstrated that studied SC-FUCs adopted random coil conformation in 150mM NaCl solution (pH 7.4). Based on the worm-like cylinder model and atomic force microscopy, the chain stiffness of SC-FUCs was further evaluated as Am-FUC≈Ib-FUC>Aj-FUC. It was suggested that the existence of branch structure increased the chain flexibility, while sulfated pattern exerted limited influence. SC-FUCs demonstrated shear-thinning rheological behavior and negative charge. Am-FUC possessed a higher thermostability than Ib-FUC and Aj-FUC. These results have important implications for understanding the molecular characteristics of SC-FUCs, which could facilitate their further application. PMID:27516290

  12. Tetrazole acetic acid: Tautomers, conformers, and isomerization

    NASA Astrophysics Data System (ADS)

    Araujo-Andrade, C.; Reva, I.; Fausto, R.

    2014-02-01

    Monomers of (tetrazol-5-yl)-acetic acid (TAA) were obtained by sublimation of the crystalline compound and the resulting vapors were isolated in cryogenic nitrogen matrices at 13 K. The conformational and tautomeric composition of TAA in the matrix was characterized by infrared spectroscopy and vibrational calculations carried out at the B3LYP/6-311++G(d,p) level. TAA may adopt two tautomeric modifications, 1H- and 2H-, depending on the position of the annular hydrogen atom. Two-dimensional potential energy surfaces (PESs) of TAA were theoretically calculated at the MP2/6-311++G(d,p) level, for each tautomer. Four and six symmetry-unique minima were located on these PESs, for 1H- and 2H-TAA, respectively. The energetics of the detected minima was subsequently refined by calculations at the QCISD level. Two 1H- and three 2H-conformers fall within the 0-8 kJ mol-1 energy range and should be appreciably populated at the sublimation temperature (˜330 K). Observation of only one conformer for each tautomer (1ccc and 2pcc) is explained in terms of calculated barriers to conformational rearrangements. All conformers with the cis O=COH moiety are separated by low barriers (less than 10 kJ mol-1) and collapse to the most stable 1ccc (1H-) and 2pcc (2H-) forms during deposition of the matrix. On the trans O=COH surfaces, the relative energies are very high (between 12 and 27 kJ mol-1). The trans forms are not thermally populated at the sublimation conditions and were not detected in matrices. One high-energy form in each tautomer, 1cct (1H-) and 2pct (2H-), was found to differ from the most stable form only by rotation of the OH group and separated from other forms by high barriers. This opened a perspective for their stabilization in a matrix. 1cct and 2pct were generated in the matrices selectively by means of narrow-band near-infrared (NIR) irradiations of the samples at 6920 and 6937 cm-1, where the first OH stretching overtone vibrations of 1ccc and 2pcc occur. The

  13. Tetrazole acetic acid: tautomers, conformers, and isomerization.

    PubMed

    Araujo-Andrade, C; Reva, I; Fausto, R

    2014-02-14

    Monomers of (tetrazol-5-yl)-acetic acid (TAA) were obtained by sublimation of the crystalline compound and the resulting vapors were isolated in cryogenic nitrogen matrices at 13 K. The conformational and tautomeric composition of TAA in the matrix was characterized by infrared spectroscopy and vibrational calculations carried out at the B3LYP/6-311++G(d,p) level. TAA may adopt two tautomeric modifications, 1H- and 2H-, depending on the position of the annular hydrogen atom. Two-dimensional potential energy surfaces (PESs) of TAA were theoretically calculated at the MP2/6-311++G(d,p) level, for each tautomer. Four and six symmetry-unique minima were located on these PESs, for 1H- and 2H-TAA, respectively. The energetics of the detected minima was subsequently refined by calculations at the QCISD level. Two 1H- and three 2H-conformers fall within the 0-8 kJ mol(-1) energy range and should be appreciably populated at the sublimation temperature (∼330 K). Observation of only one conformer for each tautomer (1ccc and 2pcc) is explained in terms of calculated barriers to conformational rearrangements. All conformers with the cis O=COH moiety are separated by low barriers (less than 10 kJ mol(-1)) and collapse to the most stable 1ccc (1H-) and 2pcc (2H-) forms during deposition of the matrix. On the trans O=COH surfaces, the relative energies are very high (between 12 and 27 kJ mol(-1)). The trans forms are not thermally populated at the sublimation conditions and were not detected in matrices. One high-energy form in each tautomer, 1cct (1H-) and 2pct (2H-), was found to differ from the most stable form only by rotation of the OH group and separated from other forms by high barriers. This opened a perspective for their stabilization in a matrix. 1cct and 2pct were generated in the matrices selectively by means of narrow-band near-infrared (NIR) irradiations of the samples at 6920 and 6937 cm(-1), where the first OH stretching overtone vibrations of 1ccc and 2pcc occur

  14. Tetrazole acetic acid: Tautomers, conformers, and isomerization

    SciTech Connect

    Araujo-Andrade, C.; Reva, I. Fausto, R.

    2014-02-14

    Monomers of (tetrazol-5-yl)-acetic acid (TAA) were obtained by sublimation of the crystalline compound and the resulting vapors were isolated in cryogenic nitrogen matrices at 13 K. The conformational and tautomeric composition of TAA in the matrix was characterized by infrared spectroscopy and vibrational calculations carried out at the B3LYP/6-311++G(d,p) level. TAA may adopt two tautomeric modifications, 1H- and 2H-, depending on the position of the annular hydrogen atom. Two-dimensional potential energy surfaces (PESs) of TAA were theoretically calculated at the MP2/6-311++G(d,p) level, for each tautomer. Four and six symmetry-unique minima were located on these PESs, for 1H- and 2H-TAA, respectively. The energetics of the detected minima was subsequently refined by calculations at the QCISD level. Two 1H- and three 2H-conformers fall within the 0–8 kJ mol{sup −1} energy range and should be appreciably populated at the sublimation temperature (∼330 K). Observation of only one conformer for each tautomer (1ccc and 2pcc) is explained in terms of calculated barriers to conformational rearrangements. All conformers with the cis O=COH moiety are separated by low barriers (less than 10 kJ mol{sup −1}) and collapse to the most stable 1ccc (1H-) and 2pcc (2H-) forms during deposition of the matrix. On the trans O=COH surfaces, the relative energies are very high (between 12 and 27 kJ mol{sup −1}). The trans forms are not thermally populated at the sublimation conditions and were not detected in matrices. One high-energy form in each tautomer, 1cct (1H-) and 2pct (2H-), was found to differ from the most stable form only by rotation of the OH group and separated from other forms by high barriers. This opened a perspective for their stabilization in a matrix. 1cct and 2pct were generated in the matrices selectively by means of narrow-band near-infrared (NIR) irradiations of the samples at 6920 and 6937 cm{sup −1}, where the first OH stretching overtone

  15. Electronic Dental Records System Adoption.

    PubMed

    Abramovicz-Finkelsztain, Renata; Barsottini, Claudia G N; Marin, Heimar Fatima

    2015-01-01

    The use of Electronic Dental Records (EDRs) and management software has become more frequent, following the increase in prevelance of new technologies and computers in dental offices. The purpose of this study is to identify and evaluate the use of EDRs by the dental community in the São Paulo city area. A quantitative case study was performed using a survey on the phone. A total of 54 offices were contacted and only one declinedparticipation in this study. Only one office did not have a computer. EDRs were used in 28 offices and only four were paperless. The lack of studies in this area suggests the need for more usability and implementation studies on EDRs so that we can improve EDR adoption by the dental community. PMID:26262001

  16. Molecular mechanics conformational analysis of tylosin

    NASA Astrophysics Data System (ADS)

    Ivanov, Petko M.

    1998-01-01

    The conformations of the 16-membered macrolide antibiotic tylosin were studied with molecular mechanics (AMBER∗ force field) including modelling of the effect of the solvent on the conformational preferences (GB/SA). A Monte Carlo conformational search procedure was used for finding the most probable low-energy conformations. The present study provides complementary data to recently reported analysis of the conformations of tylosin based on NMR techniques. A search for the low-energy conformations of protynolide, a 16-membered lactone containing the same aglycone as tylosin, was also carried out, and the results were compared with the observed conformation in the crystal as well as with the most probable conformations of the macrocyclic ring of tylosin. The dependence of the results on force field was also studied by utilizing the MM3 force field. Some particular conformations were computed with the semiempirical molecular orbital methods AM1 and PM3.

  17. In Their Own Words: Adopted Persons' Experiences of Adoption Disclosure and Discussion in Their Families

    ERIC Educational Resources Information Center

    Wydra, Maria; O'Brien, Karen M.; Merson, Erica S.

    2012-01-01

    This study explored adoption disclosure in a sample of 18 adult adoptees who were adopted as infants. A qualitative analysis of semistructured interviews with adoptees was used to learn about participants' experiences of adoption disclosure. The majority always knew they were adopted, were able to talk openly with parents about adoption, and had…

  18. Adoption of Children with Disabilities: An Exploration of the Issues for Adoptive Families

    ERIC Educational Resources Information Center

    Good, Gretchen A.

    2016-01-01

    This systematic literature review is an exploration of issues for adoptive families throughout the adoption process and into the various phases of the life of the adoptive family. Although there has been much recent research related to adoption, in general, very little adoption literature addresses the often unspoken needs of families who want to…

  19. Crystal and mol-ecular structure of aflatrem.

    PubMed

    Lenta, Bruno N; Ngatchou, Jules; Kenfack, Patrice T; Neumann, Beate; Stammler, Hans-Georg; Sewald, Norbert

    2015-11-01

    The crystal structure of the title compound, C32H39NO4, confirms the absolute configuration of the seven chiral centres in the mol-ecule. The molecule has a 1,1-dimethylprop-2-enyl substituent on the indole nucleus and this nucleus shares one edge with the five-membered ring which is, in turn, connected to a sequence of three edge-shared fused rings. The skeleton is completed by the 7,7-trimethyl-6,8-dioxabi-cyclo-[3.2.1]oct-3-en-2-one group connected to the terminal cyclohexene ring. The two cyclohexane rings adopt chair and half-chair conformations, while in the dioxabi-cyclo-[3.2.1]oct-3-en-2-one unit, the six-membered ring has a half-chair conformation. The indole system of the mol-ecule exhibits a tilt of 2.02 (1)° between its two rings. In the crystal, O-H⋯O hydrogen bonds connect mol-ecules into chains along [010]. Weak N-H⋯π inter-actions connect these chains, forming sheets parallel to (10-1). PMID:26594569

  20. Crystal and mol­ecular structure of aflatrem

    PubMed Central

    Lenta, Bruno N.; Ngatchou, Jules; Kenfack, Patrice T.; Neumann, Beate; Stammler, Hans-Georg; Sewald, Norbert

    2015-01-01

    The crystal structure of the title compound, C32H39NO4, confirms the absolute configuration of the seven chiral centres in the mol­ecule. The molecule has a 1,1-dimethylprop-2-enyl substituent on the indole nucleus and this nucleus shares one edge with the five-membered ring which is, in turn, connected to a sequence of three edge-shared fused rings. The skeleton is completed by the 7,7-trimethyl-6,8-dioxabi­cyclo­[3.2.1]oct-3-en-2-one group connected to the terminal cyclohexene ring. The two cyclohexane rings adopt chair and half-chair conformations, while in the dioxabi­cyclo­[3.2.1]oct-3-en-2-one unit, the six-membered ring has a half-chair conformation. The indole system of the mol­ecule exhibits a tilt of 2.02 (1)° between its two rings. In the crystal, O—H⋯O hydrogen bonds connect mol­ecules into chains along [010]. Weak N—H⋯π inter­actions connect these chains, forming sheets parallel to (10-1). PMID:26594569

  1. Defects in conformal field theory

    NASA Astrophysics Data System (ADS)

    Billò, Marco; Gonçalves, Vasco; Lauria, Edoardo; Meineri, Marco

    2016-04-01

    We discuss consequences of the breaking of conformal symmetry by a flat or spherical extended operator. We adapt the embedding formalism to the study of correlation functions of symmetric traceless tensors in the presence of the defect. Two-point functions of a bulk and a defect primary are fixed by conformal invariance up to a set of OPE coefficients, and we identify the allowed tensor structures. A correlator of two bulk primaries depends on two cross-ratios, and we study its conformal block decomposition in the case of external scalars. The Casimir equation in the defect channel reduces to a hypergeometric equation, while the bulk channel blocks are recursively determined in the light-cone limit. In the special case of a defect of codimension two, we map the Casimir equation in the bulk channel to the one of a four-point function without defect. Finally, we analyze the contact terms of the stress-tensor with the extended operator, and we deduce constraints on the CFT data. In two dimensions, we relate the displacement operator, which appears among the contact terms, to the reflection coefficient of a conformal interface, and we find unitarity bounds for the latter.

  2. Precision conformal optics technology program

    NASA Astrophysics Data System (ADS)

    Trotta, Patrick A.

    2001-09-01

    Conformal optics are defined as optics that deviate from conventional form to best satisfy the contour and shape needs of system platforms. Precision Conformal Optics Technology (PCOT), a comprehensive 48 month program funded by the Defense Advanced Research Program Agency (DARPA) and the U. S. Army Missile Research, Development, and Engineering Center (MRDEC), assessed the potential benefits achieved by use of conformal optics on a variety of U.S. weapon systems. Also addressed were all barriers impeding conformal optics use. The PCOT program was executed by a consortium of organizations ranging from major U.S. defense prime contractors, to small businesses, and academia. The diversity of organizations encouraged synergy across a broad array of skills and perspectives. Smooth team interaction was made possible by the 845 contractual structure of the program. Benefits identified by the PCOT consortium included major reductions in aerodynamic drag (by as much as 50%), reduced time-to-targets (by as much as 60%), and reduced weapon signatures. Impediments addressed included inadequacies in optical design tools, optical manufacturing methods and equipment, optical testing, and system integration. The PCOT program was successfully completed with a demonstration of a highly contoured missile dome, which reduced overall missile drag by 25%, and led to a predicted twofold increase in missile range.

  3. Temperature: Human Regulating, Ants Conforming

    ERIC Educational Resources Information Center

    Clopton, Joe R.

    2007-01-01

    Biological processes speed up as temperature rises. Procedures for demonstrating this with ants traveling on trails, and data gathered by students on the Argentine ant ("Linepithema humile") are presented. The concepts of temperature regulation and conformity are detailed with a focus on the processes rather than on terms that label the organisms.

  4. Parsimony in Protein Conformational Change

    PubMed Central

    Chapman, Brynmor K.; Davulcu, Omar; Skalicky, Jack J.; Brüschweiler, Rafael P.; Chapman, Michael S.

    2015-01-01

    Summary Protein conformational change is analyzed by finding the minimalist backbone torsion angle rotations that superpose crystal structures within experimental error. Of several approaches to enforcing parsimony during flexible least-squares superposition, an ℓ1-norm restraint provided greatest consistency with independent indications of flexibility from NMR relaxation dispersion and chemical shift perturbation in arginine kinase, and four previously studied systems. Crystallographic cross-validation shows that the dihedral parameterization describes conformational change more accurately than rigid-group approaches. The rotations that superpose the principal elements of structure constitute a small fraction of the raw (φ, ψ)-differences that also reflect local conformation and experimental error. Substantial long-range displacements can be mediated by modest dihedral rotations, accommodated even within α-helices and β-sheets without disruption of hydrogen bonding at the hinges. Consistency between ligand-associated and intrinsic motions (in the unliganded state) implies that induced changes tend to follow low-barrier paths between conformational sub-states that are in intrinsic dynamic equilibrium. PMID:26095029

  5. Correct Representation of Conformational Equilibria.

    ERIC Educational Resources Information Center

    Fulop, F.; And Others

    1983-01-01

    In representing conformational equilibria of compounds having only one chiral center, erroneous formulas showing different antipodes on the two sides of the equilibrium are rare. In contrast, with compounds having two or more chiral centers especially with saturated heterocycles, this erroneous representation occurs frequently in the chemical…

  6. Psychological Androgyny and Social Conformity.

    ERIC Educational Resources Information Center

    Brehony, Kathleen; And Others

    The decisions and attitudes of sex-stereotyped and androgynous individuals (as defined by the Bem Sex Role Inventory) were compared in a social conformity paradigm. On each of 160 trials subjects predicted one of two possible stimuli after hearing predictions of two other "subjects." No effects of physical sex were observed. On trials when the…

  7. S-Shaped Conformation of the Quaterthiophene Molecular Backbone in Two-Dimensional Bisterpyridine-Derivative Self-Assembled Nanoarchitecture.

    PubMed

    Kervella, Yann; Shilova, Ekaterina; Latil, Sylvain; Jousselme, Bruno; Silly, Fabien

    2015-12-15

    The conformation and the two-dimensional self-assembly of 4'-(3',4″-dihexyloxy-5,2':5',2″:5″,2‴-quaterthien-2,5‴-diyl)-bis(2,2':6',2″-terpyridine) molecules are theoretically and experimentally investigated. This molecular building block forms a hydrogen-bonded chiral supramolecular nanoarchitecture on graphite at the solid/liquid interface. Scanning tunneling microscopy (STM) shows that the molecule adopts an S-shaped conformation in this structure. DFTB+ calculations reveal that this conformation is not the lowest-energy conformation. The molecular nanoarchitecture appears to be stabilized by hydrogen bonding as well as van der Waals interactions. I-, L-, and D-shaped molecular conformations are, however, locally observed at the domain boundary, but these conformations do not self-assemble into organized 2D structures. PMID:26624809

  8. BCL::Conf: small molecule conformational sampling using a knowledge based rotamer library.

    PubMed

    Kothiwale, Sandeepkumar; Mendenhall, Jeffrey L; Meiler, Jens

    2015-01-01

    The interaction of a small molecule with a protein target depends on its ability to adopt a three-dimensional structure that is complementary. Therefore, complete and rapid prediction of the conformational space a small molecule can sample is critical for both structure- and ligand-based drug discovery algorithms such as small molecule docking or three-dimensional quantitative structure-activity relationships. Here we have derived a database of small molecule fragments frequently sampled in experimental structures within the Cambridge Structure Database and the Protein Data Bank. Likely conformations of these fragments are stored as 'rotamers' in analogy to amino acid side chain rotamer libraries used for rapid sampling of protein conformational space. Explicit fragments take into account correlations between multiple torsion bonds and effect of substituents on torsional profiles. A conformational ensemble for small molecules can then be generated by recombining fragment rotamers with a Monte Carlo search strategy. BCL::Conf was benchmarked against other conformer generator methods including Confgen, Moe, Omega and RDKit in its ability to recover experimentally determined protein bound conformations of small molecules, diversity of conformational ensembles, and sampling rate. BCL::Conf recovers at least one conformation with a root mean square deviation of 2 Å or better to the experimental structure for 99 % of the small molecules in the Vernalis benchmark dataset. The 'rotamer' approach will allow integration of BCL::Conf into respective computational biology programs such as Rosetta.Graphical abstract:Conformation sampling is carried out using explicit fragment conformations derived from crystallographic structure databases. Molecules from the database are decomposed into fragments and most likely conformations/rotamers are used to sample correspondng sub-structure of a molecule of interest. PMID:26473018

  9. Impact of Adoption on Birth Parents

    MedlinePlus

    ... This relationship, as well as the birth parent’s perception of his or her identity, may change over ... McRoy, R. G., & Grotevant, H. D. (2000). Birthmother perceptions of the psychologically present adopted child: Adoption openness ...

  10. Macro influencers of electronic health records adoption.

    PubMed

    Raghavan, Vijay V; Chinta, Ravi; Zhirkin, Nikita

    2015-01-01

    While adoption rates for electronic health records (EHRs) have improved, the reasons for significant geographical differences in EHR adoption within the USA have remained unclear. To understand the reasons for these variations across states, we have compiled from secondary sources a profile of different states within the USA, based on macroeconomic and macro health-environment factors. Regression analyses were performed using these indicator factors on EHR adoption. The results showed that internet usage and literacy are significantly associated with certain measures of EHR adoption. Income level was not significantly associated with EHR adoption. Per capita patient days (a proxy for healthcare need intensity within a state) is negatively correlated with EHR adoption rate. Health insurance coverage is positively correlated with EHR adoption rate. Older physicians (>60 years) tend to adopt EHR systems less than their younger counterparts. These findings have policy implications on formulating regionally focused incentive programs. PMID:26559074

  11. The Place of Genetic Counselling in Adoption.

    ERIC Educational Resources Information Center

    Hockey, Athel; Bain, Jill

    1982-01-01

    An approach combining social worker and geneticist expertise in adoption is outlined in the study involving 180 families. Genetic counseling has shown to be an essential safeguard to the preservation of the adoptive family unit. (Author/SW)

  12. When to Tell Your Child About Adoption

    MedlinePlus

    ... adopted youngsters need to be told about their origins, ideally even before middle childhood. Introducing the Information ... needs to have an honest understanding of his origin. Adopted children who have not been told seem ...

  13. Innovation Type, Radicalness, and the Adoption Process.

    ERIC Educational Resources Information Center

    Damanpour, Fariborz

    1988-01-01

    Reviews studies on the impact of organizational factors on the adoption of innovations along three dimensions (innovation type, innovation radicalness, and stages of adoption), finding considerable agreement. Proposes a research agenda for future studies. (SR)

  14. 75 FR 76260 - Conforming Changes to Applicant Submission Requirements; Implementing Federal Financial Report...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-08

    ... Information Relay Service at 800-877-8339. ] SUPPLEMENTARY INFORMATION: I. Background On July 15, 2010 (75 FR... published at 75 FR 41087 on July 15, 2010, is adopted as final without change. ] Dated: December 1, 2010... URBAN DEVELOPMENT 24 CFR Parts 5, 84, and 85 RIN 2501-AD50 Conforming Changes to Applicant...

  15. Conformational analysis of 2 -diphenylacetyl- 1,3 - indandione- 1 -hydrazone and its derivatives

    NASA Astrophysics Data System (ADS)

    Partridge, Ashton C.; Charlesworth, John M.

    1991-10-01

    Conformational analysis in solution of 2-diphenylacetyl-1,3-indandione-1-hydrazone (DI- PAIN, 1) and its derivatives was achieved by NMR, FT-IR and fluorescence spectroscopy. The spectral evidence indicates that the enamine tautomer is the only isomeric form adopted in solution.

  16. Learning Goals of AACSB-Accredited Undergraduate Business Programs: Predictors of Conformity versus Differentiation

    ERIC Educational Resources Information Center

    Brink, Kyle E.; Palmer, Timothy B.; Costigan, Robert D.

    2014-01-01

    Learning goals are central to assurance of learning. Yet little is known about what goals are used by business programs or how they are established. On the one hand, business schools are encouraged to develop their own unique learning goals. However, business schools also face pressures that would encourage conformity by adopting goals used by…

  17. Conformally flat static spherically symmetric perfect-fluid distribution in Einstein-Cartan theory

    NASA Astrophysics Data System (ADS)

    Kalyanshetti, S. B.; Waghmode, B. B.

    1983-06-01

    We consider the static, conformally flat spherically symmetric perfect-fluid distribution in Einstein-Cartan theory and obtain the field equations. These field equations are solved by adopting Hehl's approach with the assumption that the spins of the particles composing the fluid are all aligned in the radial direction only and the reality conditions are discussed.

  18. Multiple conformations are a conserved and regulatory feature of the RB1 5′ UTR

    PubMed Central

    Kutchko, Katrina M.; Sanders, Wes; Ziehr, Ben; Phillips, Gabriela; Solem, Amanda; Halvorsen, Matthew; Weeks, Kevin M.; Moorman, Nathaniel

    2015-01-01

    Folding to a well-defined conformation is essential for the function of structured ribonucleic acids (RNAs) like the ribosome and tRNA. Structured elements in the untranslated regions (UTRs) of specific messenger RNAs (mRNAs) are known to control expression. The importance of unstructured regions adopting multiple conformations, however, is still poorly understood. High-resolution SHAPE-directed Boltzmann suboptimal sampling of the Homo sapiens Retinoblastoma 1 (RB1) 5′ UTR yields three distinct conformations compatible with the experimental data. Private single nucleotide variants (SNVs) identified in two patients with retinoblastoma each collapse the structural ensemble to a single but distinct well-defined conformation. The RB1 5′ UTRs from Bos taurus (cow) and Trichechus manatus latirostris (manatee) are divergent in sequence from H. sapiens (human) yet maintain structural compatibility with high-probability base pairs. SHAPE chemical probing of the cow and manatee RB1 5′ UTRs reveals that they also adopt multiple conformations. Luciferase reporter assays reveal that 5′ UTR mutations alter RB1 expression. In a traditional model of disease, causative SNVs disrupt a key structural element in the RNA. For the subset of patients with heritable retinoblastoma-associated SNVs in the RB1 5′ UTR, the absence of multiple structures is likely causative of the cancer. Our data therefore suggest that selective pressure will favor multiple conformations in eukaryotic UTRs to regulate expression. PMID:25999316

  19. Multiple conformations are a conserved and regulatory feature of the RB1 5' UTR.

    PubMed

    Kutchko, Katrina M; Sanders, Wes; Ziehr, Ben; Phillips, Gabriela; Solem, Amanda; Halvorsen, Matthew; Weeks, Kevin M; Moorman, Nathaniel; Laederach, Alain

    2015-07-01

    Folding to a well-defined conformation is essential for the function of structured ribonucleic acids (RNAs) like the ribosome and tRNA. Structured elements in the untranslated regions (UTRs) of specific messenger RNAs (mRNAs) are known to control expression. The importance of unstructured regions adopting multiple conformations, however, is still poorly understood. High-resolution SHAPE-directed Boltzmann suboptimal sampling of the Homo sapiens Retinoblastoma 1 (RB1) 5' UTR yields three distinct conformations compatible with the experimental data. Private single nucleotide variants (SNVs) identified in two patients with retinoblastoma each collapse the structural ensemble to a single but distinct well-defined conformation. The RB1 5' UTRs from Bos taurus (cow) and Trichechus manatus latirostris (manatee) are divergent in sequence from H. sapiens (human) yet maintain structural compatibility with high-probability base pairs. SHAPE chemical probing of the cow and manatee RB1 5' UTRs reveals that they also adopt multiple conformations. Luciferase reporter assays reveal that 5' UTR mutations alter RB1 expression. In a traditional model of disease, causative SNVs disrupt a key structural element in the RNA. For the subset of patients with heritable retinoblastoma-associated SNVs in the RB1 5' UTR, the absence of multiple structures is likely causative of the cancer. Our data therefore suggest that selective pressure will favor multiple conformations in eukaryotic UTRs to regulate expression. PMID:25999316

  20. The Adopted Adolescent. Selected Papers Number 55.

    ERIC Educational Resources Information Center

    Banning, Anne

    This review of studies on clinical and nonclinical populations explores outcomes of adoption and developmental issues for adolescents, and in particular, developmental problems for adopted adolescents. Studies on nonclinical populations demonstrate that adoption is a highly successful form of substitute care. Prospective longitudinal studies show…

  1. 47 CFR 61.171 - Adoption notice.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 3 2013-10-01 2013-10-01 false Adoption notice. 61.171 Section 61.171 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) TARIFFS Adoption of Tariffs and Other Documents of Predecessor Carriers § 61.171 Adoption notice. When a...

  2. 47 CFR 61.171 - Adoption notice.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 3 2014-10-01 2014-10-01 false Adoption notice. 61.171 Section 61.171 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) TARIFFS Adoption of Tariffs and Other Documents of Predecessor Carriers § 61.171 Adoption notice. When a...

  3. 14 CFR 221.160 - Adoption notice.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Adoption notice. 221.160 Section 221.160... REGULATIONS TARIFFS Adoption Publications Required To Show Change in Carrier's Name or Transfer of Operating Control § 221.160 Adoption notice. (a) When the name of a carrier is changed or when its operating...

  4. 32 CFR 584.4 - Adoption proceedings.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 3 2011-07-01 2009-07-01 true Adoption proceedings. 584.4 Section 584.4... CUSTODY, AND PATERNITY § 584.4 Adoption proceedings. (a) General. This chapter does not apply to those... normally may not be put up for adoption without the consent of the parents. Therefore, communications...

  5. 40 CFR 1506.3 - Adoption.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Adoption. 1506.3 Section 1506.3 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY OTHER REQUIREMENTS OF NEPA § 1506.3 Adoption. (a) An agency may adopt a Federal draft or final environmental impact statement or portion...

  6. 40 CFR 1506.3 - Adoption.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Adoption. 1506.3 Section 1506.3 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY OTHER REQUIREMENTS OF NEPA § 1506.3 Adoption. (a) An agency may adopt a Federal draft or final environmental impact statement or portion...

  7. 14 CFR 221.160 - Adoption notice.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Adoption notice. 221.160 Section 221.160... REGULATIONS TARIFFS Adoption Publications Required To Show Change in Carrier's Name or Transfer of Operating Control § 221.160 Adoption notice. (a) When the name of a carrier is changed or when its operating...

  8. 32 CFR 584.4 - Adoption proceedings.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 3 2014-07-01 2014-07-01 false Adoption proceedings. 584.4 Section 584.4... CUSTODY, AND PATERNITY § 584.4 Adoption proceedings. (a) General. This chapter does not apply to those... normally may not be put up for adoption without the consent of the parents. Therefore, communications...

  9. 47 CFR 61.171 - Adoption notice.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Adoption notice. 61.171 Section 61.171 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) TARIFFS Adoption of Tariffs and Other Documents of Predecessor Carriers § 61.171 Adoption notice. When a...

  10. 14 CFR 221.160 - Adoption notice.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Adoption notice. 221.160 Section 221.160... REGULATIONS TARIFFS Adoption Publications Required To Show Change in Carrier's Name or Transfer of Operating Control § 221.160 Adoption notice. (a) When the name of a carrier is changed or when its operating...

  11. 25 CFR 75.18 - Adoption.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Adoption. 75.18 Section 75.18 Indians BUREAU OF INDIAN... OF CHEROKEE INDIANS, NORTH CAROLINA § 75.18 Adoption. The Tribal Council of the Eastern Band of Cherokee Indians shall be empowered to enact ordinances governing the adoption of new members....

  12. 32 CFR 584.4 - Adoption proceedings.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 3 2013-07-01 2013-07-01 false Adoption proceedings. 584.4 Section 584.4... CUSTODY, AND PATERNITY § 584.4 Adoption proceedings. (a) General. This chapter does not apply to those... normally may not be put up for adoption without the consent of the parents. Therefore, communications...

  13. 40 CFR 1506.3 - Adoption.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Adoption. 1506.3 Section 1506.3 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY OTHER REQUIREMENTS OF NEPA § 1506.3 Adoption. (a) An agency may adopt a Federal draft or final environmental impact statement or portion...

  14. 25 CFR 75.18 - Adoption.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Adoption. 75.18 Section 75.18 Indians BUREAU OF INDIAN... OF CHEROKEE INDIANS, NORTH CAROLINA § 75.18 Adoption. The Tribal Council of the Eastern Band of Cherokee Indians shall be empowered to enact ordinances governing the adoption of new members....

  15. 14 CFR 221.160 - Adoption notice.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Adoption notice. 221.160 Section 221.160... REGULATIONS TARIFFS Adoption Publications Required To Show Change in Carrier's Name or Transfer of Operating Control § 221.160 Adoption notice. (a) When the name of a carrier is changed or when its operating...

  16. 47 CFR 61.171 - Adoption notice.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Adoption notice. 61.171 Section 61.171 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) TARIFFS Adoption of Tariffs and Other Documents of Predecessor Carriers § 61.171 Adoption notice. When a...

  17. A Narrative Inquiry of International Adoption Stories

    ERIC Educational Resources Information Center

    Pryor, Christin; Pettinelli, J. Douglas

    2011-01-01

    The international adoption entrance story is an unexplored topic in the adoption literature. The stories that families tell of beginning life with their new children has important implications for the development of an autobiographical narrative of an adopted child. A coherent autobiographical narrative is vital for healthy childhood development.…

  18. 25 CFR 75.18 - Adoption.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Adoption. 75.18 Section 75.18 Indians BUREAU OF INDIAN... OF CHEROKEE INDIANS, NORTH CAROLINA § 75.18 Adoption. The Tribal Council of the Eastern Band of Cherokee Indians shall be empowered to enact ordinances governing the adoption of new members....

  19. 25 CFR 75.18 - Adoption.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Adoption. 75.18 Section 75.18 Indians BUREAU OF INDIAN... OF CHEROKEE INDIANS, NORTH CAROLINA § 75.18 Adoption. The Tribal Council of the Eastern Band of Cherokee Indians shall be empowered to enact ordinances governing the adoption of new members....

  20. 40 CFR 1506.3 - Adoption.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Adoption. 1506.3 Section 1506.3 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY OTHER REQUIREMENTS OF NEPA § 1506.3 Adoption. (a) An agency may adopt a Federal draft or final environmental impact statement or portion...

  1. 47 CFR 61.171 - Adoption notice.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 3 2012-10-01 2012-10-01 false Adoption notice. 61.171 Section 61.171 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) TARIFFS Adoption of Tariffs and Other Documents of Predecessor Carriers § 61.171 Adoption notice. When a...

  2. 32 CFR 584.4 - Adoption proceedings.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 3 2012-07-01 2009-07-01 true Adoption proceedings. 584.4 Section 584.4... CUSTODY, AND PATERNITY § 584.4 Adoption proceedings. (a) General. This chapter does not apply to those... normally may not be put up for adoption without the consent of the parents. Therefore, communications...

  3. 40 CFR 1506.3 - Adoption.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Adoption. 1506.3 Section 1506.3 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY OTHER REQUIREMENTS OF NEPA § 1506.3 Adoption. (a) An agency may adopt a Federal draft or final environmental impact statement or portion...

  4. 25 CFR 75.18 - Adoption.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Adoption. 75.18 Section 75.18 Indians BUREAU OF INDIAN... OF CHEROKEE INDIANS, NORTH CAROLINA § 75.18 Adoption. The Tribal Council of the Eastern Band of Cherokee Indians shall be empowered to enact ordinances governing the adoption of new members....

  5. 14 CFR 221.160 - Adoption notice.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Adoption notice. 221.160 Section 221.160... REGULATIONS TARIFFS Adoption Publications Required To Show Change in Carrier's Name or Transfer of Operating Control § 221.160 Adoption notice. (a) When the name of a carrier is changed or when its operating...

  6. Modeling technology adoption in developing countries

    SciTech Connect

    Besley, T.; Case, A. )

    1993-05-01

    An analysis of technology adoption decisions by poor farmers is provided. Some possible empirical models for studying technology adoption are reviewed. The issue of theoretical consistency is dealt with in terms of the costs of such consistency, measured in data needs and model complexity, and the benefits, measured in terms of understanding the micro-economic foundations of adoption.

  7. Adoption Bibliography and Multi-Ethnic Sourcebook.

    ERIC Educational Resources Information Center

    Van Why, Elizabeth Wharton, Comp.

    Designed for parents who have adopted or who contemplate adoption, and for educational, legal, medical, social, and theological professionals, this bibliography and source book contains over 1250 citations relating to adoption. The book is divided into two parts. The first section is a bibliography of articles, personal narratives, dissertations,…

  8. Child Adoption in Contemporary Rural China

    ERIC Educational Resources Information Center

    Zhang, Weiguo

    2006-01-01

    Based on qualitative information from in-depth interviews and quantitative data from a survey of 425 adoptive families conducted in summer 2001 in rural China, this study attempts to explain the social and demographic patterns of adoption and investigate the roles of the State and families in adoption processes in contemporary rural China. Within…

  9. International Adoption: Current Status and Future Prospects.

    ERIC Educational Resources Information Center

    Bartholet, Elizabeth

    1993-01-01

    Laws regulating adoption are varied and complex in countries that offer children for international adoption (IA), while United States Immigration laws pose additional obstacles to Americans wishing to adopt foreign-born children. Declarations by the United Nations and the development of a convention on IA by the Hague Conference offer some hope…

  10. Conformal Gravity rotation curves with a conformal Higgs halo

    NASA Astrophysics Data System (ADS)

    Horne, Keith

    2016-06-01

    We discuss the effect of a conformally coupled Higgs field on conformal gravity (CG) predictions for the rotation curves of galaxies. The Mannheim-Kazanas (MK) metric is a valid vacuum solution of CG's fourth-order Poisson equation if and only if the Higgs field has a particular radial profile, S(r) = S0 a/(r + a), decreasing from S0 at r = 0 with radial scalelength a. Since particle rest masses scale with S(r)/S0, their world lines do not follow time-like geodesics of the MK metric gμν, as previously assumed, but rather those of the Higgs-frame MK metric tilde{g}_{μ ν }=Ω ^2 g_{μ ν }, with the conformal factor Ω(r) = S(r)/S0. We show that the required stretching of the MK metric exactly cancels the linear potential that has been invoked to fit galaxy rotation curves without dark matter. We also formulate, for spherical structures with a Higgs halo S(r), the CG equations that must be solved for viable astrophysical tests of CG using galaxy and cluster dynamics and lensing.

  11. Islands of conformational stability for filopodia.

    PubMed

    Daniels, D Robert; Turner, Matthew S

    2013-01-01

    Filopodia are long, thin protrusions formed when bundles of fibers grow outwardly from a cell surface while remaining closed in a membrane tube. We study the subtle issue of the mechanical stability of such filopodia and how this depends on the deformation of the membrane that arises when the fiber bundle adopts a helical configuration. We calculate the ground state conformation of such filopodia, taking into account the steric interaction between the membrane and the enclosed semiflexible fiber bundle. For typical filopodia we find that a minimum number of fibers is required for filopodium stability. Our calculation elucidates how experimentally observed filopodia can obviate the classical Euler buckling condition and remain stable up to several tens of μm. We briefly discuss how experimental observation of the results obtained in this work for the helical-like deformations of enclosing membrane tubes in filopodia could possibly be observed in the acrosomal reactions of the sea cucumber Thyone, and the horseshoe crab Limulus. Any realistic future theories for filopodium stability are likely to rely on an accurate treatment of such steric effects, as analysed in this work. PMID:23555612

  12. Conformal triality of the Kepler problem

    NASA Astrophysics Data System (ADS)

    Cariglia, Marco

    2016-08-01

    We show that the Kepler problem is projectively equivalent to null geodesic motion on the conformal compactification of Minkowski-4 space. This space realises the conformal triality of Minkowski, dS and AdS spaces.

  13. Killing Initial Data on spacelike conformal boundaries

    NASA Astrophysics Data System (ADS)

    Paetz, Tim-Torben

    2016-08-01

    We analyze Killing Initial Data on Cauchy surfaces in conformally rescaled vacuum space-times satisfying Friedrich's conformal field equations. As an application, we derive the KID equations on a spacelike ℐ-.

  14. Gauge natural formulation of conformal gravity

    SciTech Connect

    Campigotto, M.; Fatibene, L.

    2015-03-15

    We consider conformal gravity as a gauge natural theory. We study its conservation laws and superpotentials. We also consider the Mannheim and Kazanas spherically symmetric vacuum solution and discuss conserved quantities associated to conformal and diffeomorphism symmetries.

  15. The Conformational Behaviour of Glucosamine

    NASA Astrophysics Data System (ADS)

    Peña, Isabel; Kolesniková, Lucie; Cabezas, Carlos; Bermúdez, Celina; Berdakin, Matías; Simao, Alcides; Alonso, José L.

    2014-06-01

    A laser ablation method has been successfully used to vaporize the bioactive amino monosaccharide D-glucosamine. Three cyclic α-4C1 pyranose forms have been identified using a combination of CP-FTMW and LA-MB-FTMW spectroscopy. Stereoelectronic hyperconjugative factors, like those associated with anomeric or gauche effects, as well as the cooperative OH\\cdotsO, OH\\cdotsN and NH\\cdotsO chains, extended along the entire molecule, are the main factors driving the conformational behavior. All observed conformers exhibit a counter-clockwise arrangement (cc) of the network of intramolecular hydrogen bonds. The results are compared with those recently obtained for D-glucose. J. L. Alonso, M. A. Lozoya, I. Peña, J. C. López, C. Cabezas, S. Mata, S. Blanco, Chem. Sci. 2014, 5, 515.

  16. Boundary terms of conformal anomaly

    NASA Astrophysics Data System (ADS)

    Solodukhin, Sergey N.

    2016-01-01

    We analyze the structure of the boundary terms in the conformal anomaly integrated over a manifold with boundaries. We suggest that the anomalies of type B, polynomial in the Weyl tensor, are accompanied with the respective boundary terms of the Gibbons-Hawking type. Their form is dictated by the requirement that they produce a variation which compensates the normal derivatives of the metric variation on the boundary in order to have a well-defined variational procedure. This suggestion agrees with recent findings in four dimensions for free fields of various spins. We generalize this consideration to six dimensions and derive explicitly the respective boundary terms. We point out that the integrated conformal anomaly in odd dimensions is non-vanishing due to the boundary terms. These terms are specified in three and five dimensions.

  17. Holographic multiverse and conformal invariance

    SciTech Connect

    Garriga, Jaume; Vilenkin, Alexander E-mail: vilenkin@cosmos.phy.tufts.edu

    2009-11-01

    We consider a holographic description of the inflationary multiverse, according to which the wave function of the universe is interpreted as the generating functional for a lower dimensional Euclidean theory. We analyze a simple model where transitions between inflationary vacua occur through bubble nucleation, and the inflating part of spacetime consists of de Sitter regions separated by thin bubble walls. In this model, we present some evidence that the dual theory is conformally invariant in the UV.

  18. [Attachment and Adoption: Diagnostics, Psychopathology, and Therapy].

    PubMed

    Brisch, Karl-Heinz

    2015-01-01

    This presentation describes the development of attachment between adopted children and their adoptive parents with a focus on the particular issues seen in international adoptions. The questions of settling in, trauma in the country of origin, and the motivations of the adoptive parents will be discussed. Diagnosis and various psychopathological manifestations will be examined, as will outpatient and inpatient modes of therapy. The treatment of children of various ages will be covered along with the necessity for intensive counseling and psychotherapy for the adoptive parents. This will enable the parents to work through early trauma, which will give them and their adopted child the basis for developing healthy attachment patterns. This in turn will enable the child to mature and integrate into society. Possibilities of prevention are discussed. Many of the approaches discussed here regarding attachment and adoption may be applied to foster children and their foster parents. PMID:26645775

  19. The Conformational Landscape of Serinol

    NASA Astrophysics Data System (ADS)

    Sanz, M. Eugenia; Loru, Donatella; Peña, Isabel; Alonso, José L.

    2014-06-01

    The rotational spectrum of the amino alcohol serinol CH_2OH--CH(NH_2)--CH_2OH, which constitutes the hydrophilic head of the lipid sphingosine, has been investigated using chirped-pulsed Fourier transform microwave spectroscopy in combination with laser ablation Five different forms of serinol have been observed and conclusively identified by the comparison between the experimental values of their rotational and 14N quadrupole coupling constants and those predicted by ab initio calculations. In all observed conformers several hydrogen bonds are established between the two hydroxyl groups and the amino groups in a chain or circular arrangement. The most abundant conformer is stabilised by O--H···N and N--H···O hydrogen bonds forming a chain rather than a cycle. One of the detected conformers presents a tunnelling motion of the hydrogen atoms of the functional groups similar to that observed in glycerol. S. Mata, I. Peña, C. Cabezas, J. C. López, J. L. Alonso, J. Mol. Spectrosc. 2012, 280, 91 V. V. Ilyushin, R. A. Motiyenko, F. J. Lovas, D. F. Plusquellic, J. Mol. Spectrosc. 2008, 251, 129.

  20. Conformational isomerism in 1-heptanal

    NASA Astrophysics Data System (ADS)

    Fisher, Jonathan M.; Xu, Li-Hong; Suenram, R. D.; Pate, Brooks; Douglass, Kevin

    2006-08-01

    The rotational spectrum of 1-heptanal has been recorded over the 10-22 GHz region using a pulsed-molecular-beam, Fourier transform microwave spectrometer. The spectrum has been analyzed using the jb95 spectral analysis program. The spectra of 13 conformational isomers have been identified and assigned in the rich soup of observed transitions. Transitions of these isomers have relative intensities that are well above the intensity level of the onset of 13C isotopomers, which are a factor of 100 down in intensity. In addition to the above 13 isomers, two additional spectra were identified and assigned that belong to dimers that consist of 1-heptanal and one water molecule. In order to map the observed spectra to conformational geometries, high-level ab initio calculations have been carried out. All 15 observed conformers have been associated with ab initio determined structure configurations. In general, the agreement in rotational constants and dipole intensity pattern between the ab initio results and the experimentally observed spectra is quite good.

  1. Conformational Isomerism in 1-Heptanal

    NASA Astrophysics Data System (ADS)

    Fisher, Jonathan M.; Xu, Li-Hong; Suemran, R. D.; Pate, Brooks; Douglass, Kevin

    2006-03-01

    The rotational spectrum of 1-heptanal has been recorded over the 10 GHz to 22 GHz region using a pulsed-molecular-beam, Fourier transform microwave spectrometer. The spectrum has been analyzed using the jb95 spectral analysis program. The spectra of thirteen conformational isomers have been identified and assigned in the rich soup of observed transitions. Transitions of these isomers have relative intensities that are well above the intensity level of the onset of ^13C isotopomers, which are a factor of 100 down in intensity. In addition to the above 13 isomers, two additional spectra were identified and assigned that belong to dimers that consist of 1-heptanal and one water molecule. In order to map the observed spectra to conformational geometries, high-level ab initio calculations have been carried out. All fifteen observed conformers have been associated with ab initio determined structure configurations. In general, the agreement in rotational constants and dipole intensity pattern between the ab initio results and the experimentally observed spectra is quite good.

  2. Conformal Invariance of Graphene Sheets

    PubMed Central

    Giordanelli, I.; Posé, N.; Mendoza, M.; Herrmann, H. J.

    2016-01-01

    Suspended graphene sheets exhibit correlated random deformations that can be studied under the framework of rough surfaces with a Hurst (roughness) exponent 0.72 ± 0.01. Here, we show that, independent of the temperature, the iso-height lines at the percolation threshold have a well-defined fractal dimension and are conformally invariant, sharing the same statistical properties as Schramm-Loewner evolution (SLEκ) curves with κ = 2.24 ± 0.07. Interestingly, iso-height lines of other rough surfaces are not necessarily conformally invariant even if they have the same Hurst exponent, e.g. random Gaussian surfaces. We have found that the distribution of the modulus of the Fourier coefficients plays an important role on this property. Our results not only introduce a new universality class and place the study of suspended graphene membranes within the theory of critical phenomena, but also provide hints on the long-standing question about the origin of conformal invariance in iso-height lines of rough surfaces. PMID:26961723

  3. Conformational kinetics of aliphatic tails

    NASA Astrophysics Data System (ADS)

    Ferrarini, Alberta; Moro, Giorgio; Nordio, Pier Luigi

    The master equation describing the random walk between sites identified with the stable conformers of a chain molecule, represents the extension to the time domain of the Rotational Isomeric State model. The asymptotic analysis of the multidimensional diffusion equation in the continuous torsional variables subjected to the configurational potential, provides a rigorous justification for the discrete models, and it supplies, without resorting to phenomenological parameters, molecular definitions of the kinetic rates for the conformational transitions occurring at each segment of the chain. The coupling between the torsional variables is fully taken into account, giving rise to cooperative effects. A complete calculation of the specific correlation functions which describe the time evolution of the angular functions probed by N.M.R. and dielectric relaxation measurements, has been performed for alkyl chains attached to a massive core. The resulting behaviour has been compared with the decay of trans and gauche populations of specific bonds, expressed in terms of suitable correlation functions whose time integrals lead quite naturally to the definition of effective kinetic constants for the conformational transitions.

  4. Conformal Invariance of Graphene Sheets.

    PubMed

    Giordanelli, I; Posé, N; Mendoza, M; Herrmann, H J

    2016-01-01

    Suspended graphene sheets exhibit correlated random deformations that can be studied under the framework of rough surfaces with a Hurst (roughness) exponent 0.72 ± 0.01. Here, we show that, independent of the temperature, the iso-height lines at the percolation threshold have a well-defined fractal dimension and are conformally invariant, sharing the same statistical properties as Schramm-Loewner evolution (SLEκ) curves with κ = 2.24 ± 0.07. Interestingly, iso-height lines of other rough surfaces are not necessarily conformally invariant even if they have the same Hurst exponent, e.g. random Gaussian surfaces. We have found that the distribution of the modulus of the Fourier coefficients plays an important role on this property. Our results not only introduce a new universality class and place the study of suspended graphene membranes within the theory of critical phenomena, but also provide hints on the long-standing question about the origin of conformal invariance in iso-height lines of rough surfaces. PMID:26961723

  5. Electrophysiological precursors of social conformity.

    PubMed

    Shestakova, Anna; Rieskamp, Jörg; Tugin, Sergey; Ossadtchi, Alexey; Krutitskaya, Janina; Klucharev, Vasily

    2013-10-01

    Humans often change their beliefs or behavior due to the behavior or opinions of others. This study explored, with the use of human event-related potentials (ERPs), whether social conformity is based on a general performance-monitoring mechanism. We tested the hypothesis that conflicts with a normative group opinion evoke a feedback-related negativity (FRN) often associated with performance monitoring and subsequent adjustment of behavior. The experimental results show that individual judgments of facial attractiveness were adjusted in line with a normative group opinion. A mismatch between individual and group opinions triggered a frontocentral negative deflection with the maximum at 200 ms, similar to FRN. Overall, a conflict with a normative group opinion triggered a cascade of neuronal responses: from an earlier FRN response reflecting a conflict with the normative opinion to a later ERP component (peaking at 380 ms) reflecting a conforming behavioral adjustment. These results add to the growing literature on neuronal mechanisms of social influence by disentangling the conflict-monitoring signal in response to the perceived violation of social norms and the neural signal of a conforming behavioral adjustment. PMID:22683703

  6. Shanghai adopts family planning regulations.

    PubMed

    1990-04-01

    These Regulations, adopted by the Municipal People's Congress of Shanghai on 14 March 1990, do the following: a) strictly prohibit any units and individuals from identifying the sex of a fetus without medical reasons; b) add 1 additional week to the marriage leave of couples who marry at the age set for late marriage (25 for males and 23 for females); c) add 15 days of maternity leave for women who give birth at the age set for late birth (24) and 3 days for their spouses; d) impose a fine equal to 3 to 6 times their average annual income if a couple have an unplanned birth (calculated on the basis of their income 2 years before the birth); and e) subject a couple who have an unplanned birth to disciplinary action by their working units if they work for others or by the administrative department of industry and commerce if they are self employed. Second births are allowed if a first child "can not become normal because of nonhereditary diseases," if both husband and wife are single children, or if a "remarried couple had only one child before their remarriage." The Regulations provide that "the improvement of birth quality and good upbringing of children should be promoted, advice on heredity should be provided, and premarital examinations [should] be conducted." They also stipulate that "A woman should terminate her pregnancy or undergo a sterilization operation if both husband and wife (or either of them) have [a] hereditary or other disease not medically suitable for birth." The provisions of these Regulations prohibiting prenatal sex selection were reported in Annual Review of Population Law, Vol. 17, 1990, Section 240. PMID:12348767

  7. Real-space visualization of conformation-independent oligothiophene electronic structure

    NASA Astrophysics Data System (ADS)

    Taber, Benjamen N.; Kislitsyn, Dmitry A.; Gervasi, Christian F.; Mills, Jon M.; Rosenfield, Ariel E.; Zhang, Lei; Mannsfeld, Stefan C. B.; Prell, James S.; Briseno, Alejandro L.; Nazin, George V.

    2016-05-01

    We present scanning tunneling microscopy and spectroscopy (STM/STS) investigations of the electronic structures of different alkyl-substituted oligothiophenes on the Au(111) surface. STM imaging showed that on Au(111), oligothiophenes adopted distinct straight and bent conformations. By combining STS maps with STM images, we visualize, in real space, particle-in-a-box-like oligothiophene molecular orbitals. We demonstrate that different planar conformers with significant geometrical distortions of oligothiophene backbones surprisingly exhibit very similar electronic structures, indicating a low degree of conformation-induced electronic disorder. The agreement of these results with gas-phase density functional theory calculations implies that the oligothiophene interaction with the Au(111) surface is generally insensitive to molecular conformation.

  8. Real-space visualization of conformation-independent oligothiophene electronic structure.

    PubMed

    Taber, Benjamen N; Kislitsyn, Dmitry A; Gervasi, Christian F; Mills, Jon M; Rosenfield, Ariel E; Zhang, Lei; Mannsfeld, Stefan C B; Prell, James S; Briseno, Alejandro L; Nazin, George V

    2016-05-21

    We present scanning tunneling microscopy and spectroscopy (STM/STS) investigations of the electronic structures of different alkyl-substituted oligothiophenes on the Au(111) surface. STM imaging showed that on Au(111), oligothiophenes adopted distinct straight and bent conformations. By combining STS maps with STM images, we visualize, in real space, particle-in-a-box-like oligothiophene molecular orbitals. We demonstrate that different planar conformers with significant geometrical distortions of oligothiophene backbones surprisingly exhibit very similar electronic structures, indicating a low degree of conformation-induced electronic disorder. The agreement of these results with gas-phase density functional theory calculations implies that the oligothiophene interaction with the Au(111) surface is generally insensitive to molecular conformation. PMID:27208961

  9. 21 CFR 886.3130 - Ophthalmic conformer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic conformer. 886.3130 Section 886.3130...) MEDICAL DEVICES OPHTHALMIC DEVICES Prosthetic Devices § 886.3130 Ophthalmic conformer. (a) Identification. An ophthalmic conformer is a device usually made of molded plastic intended to be...

  10. On the cohomology of Leibniz conformal algebras

    NASA Astrophysics Data System (ADS)

    Zhang, Jiao

    2015-04-01

    We construct a new cohomology complex of Leibniz conformal algebras with coefficients in a representation instead of a module. The low-dimensional cohomology groups of this complex are computed. Meanwhile, we construct a Leibniz algebra from a Leibniz conformal algebra and prove that the category of Leibniz conformal algebras is equivalent to the category of equivalence classes of formal distribution Leibniz algebras.

  11. An extension theorem for conformal gauge singularities

    SciTech Connect

    Luebbe, Christian; Tod, Paul

    2009-11-15

    We analyze conformal gauge, or isotropic, singularities in cosmological models in general relativity. Using the calculus of tractors, we find conditions in terms of tractor curvature for a local extension of the conformal structure through a cosmological singularity and prove a local extension theorem along a congruence of timelike conformal geodesics.

  12. 40 CFR 52.799 - Transportation conformity.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Transportation conformity. 52.799... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Indiana § 52.799 Transportation conformity. On June 4, 2010, Indiana submitted the Transportation Conformity Consultation SIP consisting...

  13. 40 CFR 52.799 - Transportation conformity.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Transportation conformity. 52.799... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Indiana § 52.799 Transportation conformity. On June 4, 2010, Indiana submitted the Transportation Conformity Consultation SIP consisting...

  14. 40 CFR 52.799 - Transportation conformity.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Transportation conformity. 52.799... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Indiana § 52.799 Transportation conformity. On June 4, 2010, Indiana submitted the Transportation Conformity Consultation SIP consisting...

  15. 40 CFR 52.799 - Transportation conformity.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Transportation conformity. 52.799... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Indiana § 52.799 Transportation conformity. On June 4, 2010, Indiana submitted the Transportation Conformity Consultation SIP consisting...

  16. In vitro and in vivo studies of the RNA conformational switch in Alfalfa mosaic virus.

    PubMed

    Chen, Shih-Cheng; Olsthoorn, René C L

    2010-02-01

    The 3' termini of Alfalfa mosaic virus (AMV) RNAs adopt two mutually exclusive conformations, a coat protein binding (CPB) and a tRNA-like (TL) conformer, which consist of a linear array of stem-loop structures and a pseudoknot structure, respectively. Previously, switching between CPB and TL conformers has been proposed as a mechanism to regulate the competing processes of translation and replication of the viral RNA (R. C. L. Olsthoorn et al., EMBO J. 18:4856-4864, 1999). In the present study, the switch between CPB and TL conformers was further investigated. First, we showed that recognition of the AMV 3' untranslated region (UTR) by a tRNA-specific enzyme (CCA-adding enzyme) in vitro is more efficient when the distribution is shifted toward the TL conformation. Second, the recognition of the 3' UTR by the viral replicase was similarly dependent on the ratio of CBP and TL conformers. Furthermore, the addition of CP, which is expected to shift the distribution toward the CPB conformer, inhibited recognition by the CCA-adding enzyme and the replicase. Finally, we monitored how the binding affinity to CP is affected by this conformational switch in the yeast three-hybrid system. Here, disruption of the pseudoknot enhanced the binding affinity to CP by shifting the balance in favor of the CPB conformer, whereas stabilizing the pseudoknot did the reverse. Together, the in vitro and in vivo data clearly demonstrate the existence of the conformational switch in the 3' UTR of AMV RNAs. PMID:19923185

  17. Conformational influence of the ribose 2'-hydroxyl group: crystal structures of DNA-RNA chimeric duplexes

    NASA Technical Reports Server (NTRS)

    Egli, M.; Usman, N.; Rich, A.

    1993-01-01

    We have crystallized three double-helical DNA-RNA chimeric duplexes and determined their structures by X-ray crystallography at resolutions between 2 and 2.25 A. The two self-complementary duplexes [r(G)d(CGTATACGC)]2 and [d(GCGT)r(A)d(TACGC)]2, as well as the Okazaki fragment d(GGGTATACGC).r(GCG)d(TATACCC), were found to adopt A-type conformations. The crystal structures are non-isomorphous, and the crystallographic environments for the three chimeras are different. A number of intramolecular interactions of the ribose 2'-hydroxyl groups contribute to the stabilization of the A-conformation. Hydrogen bonds between 2'-hydroxyls and 5'-oxygens or phosphate oxygens, in addition to the previously observed hydrogen bonds to 1'-oxygens of adjacent riboses and deoxyriboses, are observed in the DNA-RNA chimeric duplexes. The crystalline chimeric duplexes do not show a transition between the DNA A- and B-conformations. CD spectra suggest that the Okazaki fragment assumes an A-conformation in solution as well. In this molecule the three RNA residues may therefore lock the complete decamer in the A-conformation. Crystals of an all-DNA strand with the same sequence as the self-complementary chimeras show a morphology which is different from those of the chimera crystals. Moreover, the oligonucleotide does not match any of the sequence characteristics of DNAs usually adopting the A-conformation in the crystalline state (e.g., octamers with short alternating stretches of purines and pyrimidines). In DNA-RNA chimeric duplexes, it is therefore possible that a single RNA residue can drive the conformational equilibrium toward the A-conformation.

  18. Modelling galactic conformity with the colour-halo age relation in the Illustris simulation

    NASA Astrophysics Data System (ADS)

    Bray, Aaron D.; Pillepich, Annalisa; Sales, Laura V.; Zhu, Emily; Genel, Shy; Rodriguez-Gomez, Vicente; Torrey, Paul; Nelson, Dylan; Vogelsberger, Mark; Springel, Volker; Eisenstein, Daniel J.; Hernquist, Lars

    2016-01-01

    Comparisons between observational surveys and galaxy formation models find that dark matter haloes' mass can largely explain their galaxies' stellar mass. However, it remains uncertain whether additional environmental variables, known as assembly bias, are necessary to explain other galaxy properties. We use the Illustris simulation to investigate the role of assembly bias in producing galactic conformity by considering 18 000 galaxies with Mstellar > 2 × 109 M⊙. We find a significant signal of galactic conformity: out to distances of about 10 Mpc, the mean red fraction of galaxies around redder galaxies is higher than around bluer galaxies at fixed stellar mass. Dark matter haloes exhibit an analogous conformity signal, in which the fraction of haloes formed at earlier times (old haloes) is higher around old haloes than around younger ones at fixed halo mass. A plausible interpretation of galactic conformity is the combination of the halo conformity signal with the galaxy colour-halo age relation: at fixed stellar mass, particularly towards the low-mass end, Illustris' galaxy colours correlate with halo age, with the reddest galaxies (often satellites) preferentially found in the oldest haloes. We explain the galactic conformity effect with a simple semi-empirical model, assigning stellar mass via halo mass (abundance matching) and galaxy colour via halo age (age matching). Regarding comparison to observations, we conclude that the adopted selection/isolation criteria, projection effects, and stacking techniques can have a significant impact on the measured amplitude of the conformity signal.

  19. 2-Hy­droxy-16-[(E)-4-methyl­benzyl­idene]-13-(4-methyl­phen­yl)-12-phenyl-1,11-diaza­penta­cyclo­[12.3.1.02,10.03,8.010,14]octa­deca-3(8),4,6-triene-9,15-dione

    PubMed Central

    Kumar, Raju Suresh; Osman, Hasnah; Abdul Rahim, Aisyah Saad; Goh, Jia Hao; Fun, Hoong-Kun

    2010-01-01

    In the title compound, C37H32N2O3, an intra­molecular O—H⋯N hydrogen bond generates a five-membered ring, producing an S(5) motif. The piperidone ring adopts a half-chair conformation. The two fused pyrrolidine rings have similar envelope conformations. The interplanar angles between the benzene rings A/B and C/D are 75.68 (7) and 30.22 (6)°, respectively. In the crystal structure, adjacent mol­ecules are inter­connected into chains propagating along the [010] direction via inter­molecular C—H⋯O hydrogen bonds. Further stabilization is provided by weak C—H⋯π inter­actions. PMID:21588384

  20. 5′′-Benzyl­idene-5-chloro-1′,1′′-dimethyl-4′-phenyl­dispiro­[indoline-3,2′-pyrrolidine-3′,3′′-piperidine]-2,4′′-dione

    PubMed Central

    Farag, I. S. Ahmed; Girgis, Adel S.; Ramadan, A. A.; Moustafa, A. M.; Tiekink, Edward R. T.

    2014-01-01

    The title compound, C30H28ClN3O2, features two spiro links, one connecting the piperidine and pyrrolidine rings, and the other connecting the pyrrolidine ring and indole residue. The configuration about the ethene bond is E. The piperidine ring adopts a half-chair conformation where the C atom connected to the spiro-C atom lies 0.713 (3) Å out of the plane of the remaining five atoms (r.m.s. deviation = 0.086 Å). The pyrrolidine ring has an envelope conformation with the flap atom being the methyl­ene C atom. Centrosymmetric eight-membered {⋯HNCO}2 amide synthons feature in the crystal packing. These are consolidated into a three-dimensional architecture by phen­yl–pyrrolidine C—H⋯N and chloro­benzene–pyrrolidine-bound phenyl C—H⋯π inter­actions. PMID:24855467

  1. 5-Chloro-5′′-(4-chloro­benzyl­idene)-4′-(4-chloro­phen­yl)-1′,1′′-dimethyldi­spiro­[indoline-3,2′-pyrrolidine-3′,3′′-piperidine]-2,4′′-dione

    PubMed Central

    Farag, I. S. Ahmed; Girgis, Adel S.; Ramadan, A. A.; Moustafa, A. M.; Mabied, Ahmed F.

    2014-01-01

    The racemic title compound, C30H26Cl3N3O2, comprises two spiro links, the first connecting the piperidine and pyrrolidine rings and the other connecting the indole and pyrrolidine rings. The piperidine ring adopts a half-chair conformation, while the pyrrolidine ring has an envelope conformation with the unsubstituted C atom as the flap. The dihedral angles between the two p-Cl-substituted benzene rings and the indole ring are 33.13 (14) and 54.11 (14)°. In the crystal, mol­ecules form inversion dimers through pairs of N—H⋯O hydrogen bonds [graph set R 2 2(8)]. Aromatic C—H⋯O hydrogen bonds extend these dimers into a ribbon structure, enclosing R 2 2(14) ring motifs, along the a-axis direction. PMID:24765059

  2. Crystal structure of methyl 3-(3-fluoro-phen-yl)-1-methyl-1,3a,4,9b-tetra-hydro-3H-thio-chromeno[4,3-c]isoxazole-3a-carboxyl-ate.

    PubMed

    Savithri, M P; Suresh, M; Raghunathan, R; Vimala, G; SubbiahPandi, A

    2015-08-01

    In the title compound, C19H18FNO3S, the five-membered oxazolidine ring adopts an envelope conformation with the methine C atom of the fused bond as the flap. Its mean plane is oriented at a dihedral angle of 50.38 (1)° with respect to the fluoro-phenyl ring. The six-membered thio-pyran ring has a half-chair conformation and its mean plane is almost coplanar with the fused benzene ring, making a dihedral angle of 4.94 (10)°. The two aromatic rings are inclined to one another by 85.96 (11)°, and the mean planes of the oxazolidine and thio-pyran rings are inclined to one another by 57.64 (12)°. In the crystal, mol-ecules are linked by C-H⋯π inter-actions, forming a three-dimensional structure. PMID:26396818

  3. Crystal structure of 1-[2,4-bis(4-methoxy­phenyl)-3-azabicyclo[3.3.1]nonan-3-yl]ethanone

    PubMed Central

    Shreevidhyaa Suressh, V.; Sathya, S.; Akila, A.; Ponnuswamy, S.; Usha, G.

    2014-01-01

    In the title compound, C24H29NO3, the aza­bicycle contains two six-membered rings, viz. a cyclo­hexane ring and a piperidine ring. The first adopts a chair conformation and the second a half-chair conformation. The dihedral angle between their mean planes is 86.21 (13)°, indicating that they are almost perpendicular to one another. The dihedral angle between the planes of the 4-meth­oxy­phenyl rings is 17.51 (13)°, and they make dihedral angles of 81.9 (3) and 81.3 (3)° with the ethan-1-one group. In the crystal, mol­ecules are linked by C—H⋯π inter­actions forming chains along [10-1]. PMID:25484811

  4. 2-Amino-6-methyl-4,5,6,7-tetra-hydro-1-benzothio-phene-3-carbonitrile.

    PubMed

    Ziaulla, Mohamed; Banu, Afshan; Begum, Noor Shahina; Panchamukhi, Shridhar I; Khazi, I M

    2011-01-01

    In the title compound, C(10)H(12)N(2)S, one of the C atoms of the cyclo-hexene ring (at position 6) and the methyl group attached to it are disordered over two sets of sites in a 0.650 (3):0.350 (3) ratio. The cyclo-hexene ring in both the major and minor occupancy conformers adopts a half-chair conformation. The thio-phene ring is essentially planar (r.m.s. deviation = 0.05 Å). In the crystal, N-H⋯N hydrogen bonds involving the amino groups result in inversion dimers with R(2) (2)(12) graph-set motif. Further N-H⋯N hydrogen bonds involving the amino and carbonitrile groups generate zigzag chains along the a axis. PMID:21522444

  5. 2-Amino-4-methyl-4,5,6,7-tetrahydro-1-benzothiophene-3-carbonitrile.

    PubMed

    Khan, Ashraf Y; Fathima, Nikhath; Kalashetti, Mallikarjun B; Begum, Noor Shahina; Khazi, I M

    2012-10-01

    In the title compound, C(10)H(12)N(2)S, the thio-phene ring is essentially planar (r.m.s. deviation = 0.0290 Å). The two C atoms of the cyclo-hexene ring (at positions 6 and 7) are disordered over two sets of sites in a 0.810 (5):0.190 (5) ratio. The cyclo-hexene rings in both the major and minor occupancy conformers adopt a half-chair conformation. In the crystal, there are two types of N-H⋯N inter-action. One of these results in centrosymmetric head-to-head dimers corresponding to an R(2) (2)(12) graph-set motif and the other forms a 20-membered macrocyclic ring involving six mol-ecules. PMID:23125792

  6. Cellular Cations Control Conformational Switching of Inositol Pyrophosphate Analogues.

    PubMed

    Hager, Anastasia; Wu, Mingxuan; Wang, Huanchen; Brown, Nathaniel W; Shears, Stephen B; Veiga, Nicolás; Fiedler, Dorothea

    2016-08-22

    The inositol pyrophosphate messengers (PP-InsPs) are emerging as an important class of cellular regulators. These molecules have been linked to numerous biological processes, including insulin secretion and cancer cell migration, but how they trigger such a wide range of cellular responses has remained unanswered in many cases. Here, we show that the PP-InsPs exhibit complex speciation behaviour and propose that a unique conformational switching mechanism could contribute to their multifunctional effects. We synthesised non-hydrolysable bisphosphonate analogues and crystallised the analogues in complex with mammalian PPIP5K2 kinase. Subsequently, the bisphosphonate analogues were used to investigate the protonation sequence, metal-coordination properties, and conformation in solution. Remarkably, the presence of potassium and magnesium ions enabled the analogues to adopt two different conformations near physiological pH. Understanding how the intrinsic chemical properties of the PP-InsPs can contribute to their complex signalling outputs will be essential to elucidate their regulatory functions. PMID:27460418

  7. Native proteins trap high-energy transit conformations

    PubMed Central

    Brereton, Andrew E.; Karplus, P. Andrew

    2015-01-01

    During protein folding and as part of some conformational changes that regulate protein function, the polypeptide chain must traverse high-energy barriers that separate the commonly adopted low-energy conformations. How distortions in peptide geometry allow these barrier-crossing transitions is a fundamental open question. One such important transition involves the movement of a non-glycine residue between the left side of the Ramachandran plot (that is, ϕ < 0°) and the right side (that is, ϕ > 0°). We report that high-energy conformations with ϕ ~ 0°, normally expected to occur only as fleeting transition states, are stably trapped in certain highly resolved native protein structures and that an analysis of these residues provides a detailed, experimentally derived map of the bond angle distortions taking place along the transition path. This unanticipated information lays to rest any uncertainty about whether such transitions are possible and how they occur, and in doing so lays a firm foundation for theoretical studies to better understand the transitions between basins that have been little studied but are integrally involved in protein folding and function. Also, the context of one such residue shows that even a designed highly stable protein can harbor substantial unfavorable interactions. PMID:26601321

  8. Building Adoption of Visual Analytics Software

    SciTech Connect

    Chinchor, Nancy; Cook, Kristin A.; Scholtz, Jean

    2012-01-05

    Adoption of technology is always difficult. Issues such as having the infrastructure necessary to support the technology, training for users, integrating the technology into current processes and tools, and having the time, managerial support, and necessary funds need to be addressed. In addition to these issues, the adoption of visual analytics tools presents specific challenges that need to be addressed. This paper discusses technology adoption challenges and approaches for visual analytics technologies.

  9. Measures for Predictors of Innovation Adoption

    PubMed Central

    Chor, Ka Ho Brian; Wisdom, Jennifer P.; Olin, Su-Chin Serene; Hoagwood, Kimberly E.; Horwitz, Sarah M.

    2014-01-01

    Building on a narrative synthesis of adoption theories by Wisdom et al. (2013), this review identifies 118 measures associated with the 27 adoption predictors in the synthesis. The distribution of measures is uneven across the predictors and predictors vary in modifiability. Multiple dimensions and definitions of predictors further complicate measurement efforts. For state policymakers and researchers, more effective and integrated measurement can advance the adoption of complex innovations such as evidence-based practices. PMID:24740175

  10. Conformance Testing: Measurement Decision Rules

    NASA Technical Reports Server (NTRS)

    Mimbs, Scott M.

    2010-01-01

    The goal of a Quality Management System (QMS) as specified in ISO 9001 and AS9100 is to provide assurance to the customer that end products meet specifications. Measuring devices, often called measuring and test equipment (MTE), are used to provide the evidence of product conformity to specified requirements. Unfortunately, processes that employ MTE can become a weak link to the overall QMS if proper attention is not given to the measurement process design, capability, and implementation. Documented "decision rules" establish the requirements to ensure measurement processes provide the measurement data that supports the needs of the QMS. Measurement data are used to make the decisions that impact all areas of technology. Whether measurements support research, design, production, or maintenance, ensuring the data supports the decision is crucial. Measurement data quality can be critical to the resulting consequences of measurement-based decisions. Historically, most industries required simplistic, one-size-fits-all decision rules for measurements. One-size-fits-all rules in some cases are not rigorous enough to provide adequate measurement results, while in other cases are overly conservative and too costly to implement. Ideally, decision rules should be rigorous enough to match the criticality of the parameter being measured, while being flexible enough to be cost effective. The goal of a decision rule is to ensure that measurement processes provide data with a sufficient level of quality to support the decisions being made - no more, no less. This paper discusses the basic concepts of providing measurement-based evidence that end products meet specifications. Although relevant to all measurement-based conformance tests, the target audience is the MTE end-user, which is anyone using MTE other than calibration service providers. Topics include measurement fundamentals, the associated decision risks, verifying conformance to specifications, and basic measurement

  11. Measuring and Increasing Adoption Rates of Cookstoves in a Humanitarian Crisis.

    PubMed

    Wilson, Daniel L; Coyle, Jeremy; Kirk, Angeli; Rosa, Javier; Abbas, Omnia; Adam, Mohammed Idris; Gadgil, Ashok J

    2016-08-01

    Traditional smoky cooking fires are one of today's greatest environmental threats to human life. These fires, used by 40% of the global population, cause 3.9 million annual premature deaths. "Clean cookstoves" have potential to improve this situation; however, most cookstove programs do not employ objective measurement of adoption to inform design, marketing, subsidies, finance, or dissemination practices. Lack of data prevents insights and may contribute to consistently low adoption rates. In this study, we used sensors and surveys to measure objective versus self-reported adoption of freely-distributed cookstoves in an internally displaced persons camp in Darfur, Sudan. Our data insights demonstrate how to effectively measure and promote adoption, especially in a humanitarian crisis. With sensors, we measured that 71% of participants were cookstove "users" compared to 95% of respondents reporting the improved cookstove was their "primary cookstove." No line of survey questioning, whether direct or indirect, predicted sensor-measured usage. For participants who rarely or never used their cookstoves after initial dissemination ("non-users"), we found significant increases in adoption after a simple followup survey (p = 0.001). The followup converted 83% of prior "non-users" to "users" with average daily adoption of 1.7 cooking hours over 2.2 meals. This increased adoption, which we posit resulted from cookstove familiarization and social conformity, was sustained for a 2-week observation period post intervention. PMID:27435285

  12. [Health-related problems in adopted children].

    PubMed

    Laubjerg, Merete; Petersson, Birgit H

    2006-10-01

    International research shows that the standard of health among children adopted from abroad, especially those adopted by single parents, is not as good as that of other children. Danish studies indicate similar problems. The causes could be several, such as poor development in the embryonic and fetal stages, low birth weight, starvation, neglect, infections, and the lack of the natural bonds between mother and child. Surveys indicate that many adoptive parents, single parents in particular, receive children with health problems. There is no Danish research available, but it is important to be aware of these issues in order for both adoptees and adoptants to receive the most support. PMID:17059801

  13. Conformance Verification of Privacy Policies

    NASA Astrophysics Data System (ADS)

    Fu, Xiang

    Web applications are both the consumers and providers of information. To increase customer confidence, many websites choose to publish their privacy protection policies. However, policy conformance is often neglected. We propose a logic based framework for formally specifying and reasoning about the implementation of privacy protection by a web application. A first order extension of computation tree logic is used to specify a policy. A verification paradigm, built upon a static control/data flow analysis, is presented to verify if a policy is satisfied.

  14. Conformational Transitions in Molecular Systems

    NASA Astrophysics Data System (ADS)

    Bachmann, M.; Janke, W.

    2008-11-01

    Proteins are the "work horses" in biological systems. In almost all functions specific proteins are involved. They control molecular transport processes, stabilize the cell structure, enzymatically catalyze chemical reactions; others act as molecular motors in the complex machinery of molecular synthetization processes. Due to their significance, misfolds and malfunctions of proteins typically entail disastrous diseases, such as Alzheimer's disease and bovine spongiform encephalopathy (BSE). Therefore, the understanding of the trinity of amino acid composition, geometric structure, and biological function is one of the most essential challenges for the natural sciences. Here, we glance at conformational transitions accompanying the structure formation in protein folding processes.

  15. Toward TeV Conformality

    SciTech Connect

    Appelquist, T; Avakian, A; Babich, R; Brower, R C; Cheng, M; Clark, M A; Cohen, S D; Fleming, G T; Kiskis, J; Neil, E T; Osborn, J C; Rebbi, C; Schaich, D; Soltz, R; Vranas, P

    2009-11-30

    We study the chiral condensate <{bar {psi}}{psi}> for an SU(3) gauge theory with N{sub f} massless Dirac fermions in the fundamental representation when N{sub f} is increased from 2 to 6. For N{sub f} = 2, our lattice simulations of <{bar {psi}}{psi}>/F{sup 3}, where F is the Nambu-Goldstone-boson decay constant, agree with the measured QCD value. For N{sub f} = 6, this ratio shows significant enhancement, presaging an even larger enhancement anticipated as N{sub f} increases further, toward the critical value for transition from confinement to infrared conformality.

  16. The Structure and Conformation of Lys63-Linked Tetraubiquitin

    SciTech Connect

    Datta, Ajit B.; Hura, Greg L.; Wolberger, Cynthia

    2009-10-07

    Ubiquitination involves the covalent attachment of the ubiquitin (Ub) C-terminus to the lysine side chain of a substrate protein by an isopeptide bond. The modification can comprise a single Ub moiety or a chain of Ub molecules joined by isopeptide bonds between the C-terminus of one Ub with one of the seven lysine residues in the next Ub. Modification of substrate proteins with Lys63-linked poly-Ub plays a key nondegradative signaling role in many biological processes, including DNA repair and nuclear factor-{kappa}B activation, whereas substrates modified by Lys48-linked chains are targeted to the proteasome for degradation. The distinct signaling properties of alternatively linked Ub chains presumably stem from structural differences that can be distinguished by effector proteins. We have determined the crystal structure of Lys63 tetra-Ub at a resolution of 1.96 {angstrom} and performed small-angle X-ray scattering experiments and molecular dynamics simulations to probe the conformation of Lys63 tetra-Ub in solution. The chain adopts a highly extended conformation in the crystal, in contrast with the compact globular fold of Lys48 tetra-Ub. Small-angle X-ray scattering experiments show that the Lys63 tetra-Ub chain is dynamic in solution, adopting an ensemble of conformations that are more compact than the extended form in the crystal. The results of these studies provide a basis for understanding the differences in the behavior and recognition of Lys63 poly-Ub chains.

  17. Predictors of race, adoption, and sexual orientation related socialization of adoptive parents of young children.

    PubMed

    Goldberg, Abbie E; Smith, JuliAnna Z

    2016-04-01

    Using a sample of 125 lesbian, gay, and heterosexual adoptive parent couples with young children (M = 6.32 years), this study examined predictors of direct socialization (preparation for adoptism, racism, and heterosexism) and indirect socialization (modeling interactions by responding to outsiders' inquiries about their child's adoptive status, racial background, or family structure). In terms of direct socialization, parents of older children tended to engage in more socialization around adoptism and heterosexism, and parents of daughters tended to engage in more socialization around racism and heterosexism. Greater perceived child interest in adoption was related to more direct socialization around adoptism. Parents of color reported more direct socialization around racism. Having a child of color was related to more direct socialization around heterosexism. Regarding indirect socialization, sexual minority parents reported more socialization around adoption and race. Greater perceived child interest in adoption was related to more indirect adoption socialization. Being more "out" was related to more indirect socialization around parent sexual orientation. PMID:26371450

  18. Envisaging the adoption process to strengthen gay- and lesbian-headed families: recommendations for adoption professionals.

    PubMed

    Matthews, John D; Cramer, Elizabeth P

    2006-01-01

    Although a growing number of child placement agencies are serving lesbians and gay men, a dearth of literature exists for adoption agency policies and practices related to working with this population. This article explores the unique characteristics and strengths of prospective gay and lesbian adoptive parents throughout each of the three phases of the adoption process-preplacement, placement, and postplacement-as well as provides suggestions for adoption professionals working with gays and lesbians. Data from a recent qualitative study of single, gay adoptive fathers are used to illustrate examples and expose areas of potential strengths of adoptive parents not generally explored in the preplacement or preparatory stage. Special attention also is given to the continuing needs of adoptive families headed by gays and lesbians after adoptive placement. Specifically explored are the needs for developing linkages with similar families, as well as providing resources designed to promote successful outcomes of adopted children raised by gays and lesbians. PMID:16846118

  19. Conformal inflation coupled to matter

    SciTech Connect

    Brax, Philippe

    2014-05-01

    We formulate new conformal models of inflation and dark energy which generalise the Higgs-Dilaton scenario. We embed these models in unimodular gravity whose effect is to break scale invariance in the late time Universe. In the early Universe, inflation occurs close to a maximum of both the scalar potential and the scalar coupling to the Ricci scalar in the Jordan frame. At late times, the dilaton, which decouples from the dynamics during inflation, receives a potential term from unimodular gravity and leads to the acceleration of the Universe. We address two central issues in this scenario. First we show that the Damour-Polyalov mechanism, when non-relativistic matter is present prior to the start of inflation, sets the initial conditions for inflation at the maximum of the scalar potential. We then show that conformal invariance implies that matter particles are not coupled to the dilaton in the late Universe at the classical level. When fermions acquire masses at low energy, scale invariance is broken and quantum corrections induce a coupling between the dilaton and matter which is still small enough to evade the gravitational constraints in the solar system.

  20. Conformational gating of DNA conductance

    PubMed Central

    Artés, Juan Manuel; Li, Yuanhui; Qi, Jianqing; Anantram, M. P.; Hihath, Joshua

    2015-01-01

    DNA is a promising molecule for applications in molecular electronics because of its unique electronic and self-assembly properties. Here we report that the conductance of DNA duplexes increases by approximately one order of magnitude when its conformation is changed from the B-form to the A-form. This large conductance increase is fully reversible, and by controlling the chemical environment, the conductance can be repeatedly switched between the two values. The conductance of the two conformations displays weak length dependencies, as is expected for guanine-rich sequences, and can be fit with a coherence-corrected hopping model. These results are supported by ab initio electronic structure calculations that indicate that the highest occupied molecular orbital is more disperse in the A-form DNA case. These results demonstrate that DNA can behave as a promising molecular switch for molecular electronics applications and also provide additional insights into the huge dispersion of DNA conductance values found in the literature. PMID:26648400

  1. Metrics with Galilean conformal isometry

    SciTech Connect

    Bagchi, Arjun; Kundu, Arnab

    2011-03-15

    The Galilean conformal algebra (GCA) arises in taking the nonrelativistic limit of the symmetries of a relativistic conformal field theory in any dimensions. It is known to be infinite dimensional in all spacetime dimensions. In particular, the 2d GCA emerges out of a scaling limit of linear combinations of two copies of the Virasoro algebra. In this paper, we find metrics in dimensions greater than 2 which realize the finite 2d GCA (the global part of the infinite algebra) as their isometry by systematically looking at a construction in terms of cosets of this finite algebra. We list all possible subalgebras consistent with some physical considerations motivated by earlier work in this direction and construct all possible higher-dimensional nondegenerate metrics. We briefly study the properties of the metrics obtained. In the standard one higher-dimensional ''holographic'' setting, we find that the only nondegenerate metric is Minkowskian. In four and five dimensions, we find families of nontrivial metrics with a rather exotic signature. A curious feature of these metrics is that all but one of them are Ricci-scalar flat.

  2. Quantifying macromolecular conformational transition pathways

    NASA Astrophysics Data System (ADS)

    Seyler, Sean; Kumar, Avishek; Thorpe, Michael; Beckstein, Oliver

    2015-03-01

    Diverse classes of proteins function through large-scale conformational changes that are challenging for computer simulations. A range of fast path-sampling techniques have been used to generate transitions, but it has been difficult to compare paths from (and assess the relative strengths of) different methods. We introduce a comprehensive method (pathway similarity analysis, PSA) for quantitatively characterizing and comparing macromolecular pathways. The Hausdorff and Fréchet metrics (known from computational geometry) are used to quantify the degree of similarity between polygonal curves in configuration space. A strength of PSA is its use of the full information available from the 3 N-dimensional configuration space trajectory without requiring additional specific knowledge about the system. We compare a sample of eleven different methods for the closed-to-open transitions of the apo enzyme adenylate kinase (AdK) and also apply PSA to an ensemble of 400 AdK trajectories produced by dynamic importance sampling MD and the Geometrical Pathways algorithm. We discuss the method's potential to enhance our understanding of transition path sampling methods, validate them, and help guide future research toward deeper physical insights into conformational transitions.

  3. Conformational gating of DNA conductance.

    PubMed

    Artés, Juan Manuel; Li, Yuanhui; Qi, Jianqing; Anantram, M P; Hihath, Joshua

    2015-01-01

    DNA is a promising molecule for applications in molecular electronics because of its unique electronic and self-assembly properties. Here we report that the conductance of DNA duplexes increases by approximately one order of magnitude when its conformation is changed from the B-form to the A-form. This large conductance increase is fully reversible, and by controlling the chemical environment, the conductance can be repeatedly switched between the two values. The conductance of the two conformations displays weak length dependencies, as is expected for guanine-rich sequences, and can be fit with a coherence-corrected hopping model. These results are supported by ab initio electronic structure calculations that indicate that the highest occupied molecular orbital is more disperse in the A-form DNA case. These results demonstrate that DNA can behave as a promising molecular switch for molecular electronics applications and also provide additional insights into the huge dispersion of DNA conductance values found in the literature. PMID:26648400

  4. Conformational transformation and selection of synthetic prion strains

    PubMed Central

    Ghaemmaghami, Sina; Watts, Joel; Nguyen, Hoang-Oanh; Hayashi, Shigenari; DeArmond, Stephen J.; Prusiner, Stanley B.

    2011-01-01

    The prion protein (PrP) is capable of folding into multiple self-replicating prion strains that produce phenotypically distinct neurological disorders. Although prion strains often breed true upon passage, they can also transform or “mutate” despite being devoid of nucleic acids. To dissect the mechanism of prion strain transformation, we studied the physicochemical evolution of a synthetic prion strain (MoSP1) after repeated passage in mice and cultured cells. We show that MoSP1 gradually adopted shorter incubation times and lower conformational stabilities. These changes were accompanied by a structural transformation as indicated by a shift in the molecular mass of the protease-resistant core of MoSP1 from approximately 19 kDa [MoSP1(2)] to 21 kDa [MoSP1(1)]. We show that MoSP1(1) and MoSP1(2) can breed with fidelity when cloned in cells, but when present as a mixture, MoSP1(1) preferentially proliferated, leading to the disappearance of MoSP1(2). In culture, the rate of this transformation process can be influenced by the nature of the culture media and the presence of polyamidoamines. Our findings demonstrate that prions can exist as a conformationally diverse population of strains, each capable of replicating with high fidelity. Rare conformational conversion, followed by competitive selection among the resulting pool of conformers, provides a mechanism for the adaptation of the prion population to their host environment. PMID:21839745

  5. 7-Deacetyl-gedunin.

    PubMed

    Ravangpai, Warin; Theerawattananond, Thapong; Pengpreecha, Somjai; Muangsin, Nongnuj; Pudhom, Khanitha

    2010-01-01

    THE TITLE COMPOUND [SYSTEMATIC NAME: (1S,3aS,4aR,4bS,5R,6aR,10aR,10bR,12aS)-1-(furan-3-yl)-5-hy-droxy-4b,7,7,10a,12a-penta-methyl-4b,5,6,6a,7,10a,10b,11,12,12a-deca-hydro-naphtho-[2,1-f]oxireno[2,3-d]isochromene-3,8(1H,3aH)-dione], C(26)H(32)O(6), which is a limonoid-type triterpene isolated from the seeds of X. moluccensis, crystallizes with three independent mol-ecules with very similar geometries in the asymmetric unit. In each mol-ecule, the four fused six-membered rings of the genudin core adopt distorted half-chair, chair, twist-boat and twisted half-chair conformations. In the crystal, inter-molecular O-H⋯O hydrogen bonds link the mol-ecules into helical chains propagated in [100]. Weak non-classical C-H⋯O contacts further consolidate the crystal packing. PMID:21522665

  6. 7-Deacetyl­gedunin

    PubMed Central

    Ravangpai, Warin; Theerawattananond, Thapong; Pengpreecha, Somjai; Muangsin, Nongnuj; Pudhom, Khanitha

    2011-01-01

    The title compound [systematic name: (1S,3aS,4aR,4bS,5R,6aR,10aR,10bR,12aS)-1-(furan-3-yl)-5-hy­droxy-4b,7,7,10a,12a-penta­methyl-4b,5,6,6a,7,10a,10b,11,12,12a-deca­hydro­naphtho­[2,1-f]oxireno[2,3-d]isochromene-3,8(1H,3aH)-dione], C26H32O6, which is a limonoid-type triterpene isolated from the seeds of X. moluccensis, crystallizes with three independent mol­ecules with very similar geometries in the asymmetric unit. In each mol­ecule, the four fused six-membered rings of the genudin core adopt distorted half-chair, chair, twist-boat and twisted half-chair conformations. In the crystal, inter­molecular O—H⋯O hydrogen bonds link the mol­ecules into helical chains propagated in [100]. Weak non-classical C—H⋯O contacts further consolidate the crystal packing. PMID:21522665

  7. Adoption of Information Technology by Advertising Agencies.

    ERIC Educational Resources Information Center

    Herling, Thomas J.; Merskin, Debra

    Since little empirical research has been conducted on adoption of currently available information technology by the advertising industry, a study explored the extent of advertising agencies' adoption of selected information technologies such as online database services and electronic mail. The study discussed data from earlier studies and analyzed…

  8. 32 CFR 584.4 - Adoption proceedings.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... situations were a soldier is trying to adopt a child. It applies to those situations where another person is trying to adopt a legitimate or illegitimate child of a soldier. A child born in or out of wedlock... has stated that he or she is not the natural parent of the child. (v) Since the soldier is not...

  9. Faculty Adoption of Active Learning Classrooms

    ERIC Educational Resources Information Center

    Van Horne, Sam; Murniati, Cecilia Titiek

    2016-01-01

    Although post-secondary educational institutions are incorporating more active learning classrooms (ALCs) that support collaborative learning, researchers have less often examined the cultural obstacles to adoption of those environments. In this qualitative research study, we adopted the conceptual framework of activity theory to examine the…

  10. 43 CFR 10010.20 - Adoption.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Adoption. 10010.20 Section 10010.20 Public Lands: Interior Regulations Relating to Public Lands (Continued) UTAH RECLAMATION MITIGATION AND... Environmental Assessments § 10010.20 Adoption. (a) An EA prepared for a proposal before the Commission...

  11. 43 CFR 10010.20 - Adoption.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Adoption. 10010.20 Section 10010.20 Public Lands: Interior Regulations Relating to Public Lands (Continued) UTAH RECLAMATION MITIGATION AND... Environmental Assessments § 10010.20 Adoption. (a) An EA prepared for a proposal before the Commission...

  12. 43 CFR 10010.20 - Adoption.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Adoption. 10010.20 Section 10010.20 Public Lands: Interior Regulations Relating to Public Lands (Continued) UTAH RECLAMATION MITIGATION AND... Environmental Assessments § 10010.20 Adoption. (a) An EA prepared for a proposal before the Commission...

  13. 43 CFR 10010.20 - Adoption.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Adoption. 10010.20 Section 10010.20 Public Lands: Interior Regulations Relating to Public Lands (Continued) UTAH RECLAMATION MITIGATION AND... Environmental Assessments § 10010.20 Adoption. (a) An EA prepared for a proposal before the Commission...

  14. Single Adoptive Mothers and Their Children

    ERIC Educational Resources Information Center

    Dougherty, Sharon Ann

    1978-01-01

    In view of the increasing number of single women who adopt children, the social work profession has an obligation to learn more about this group of mothers. This article is based on a research study to identify characteristics of single adoptive mothers and their children and to learn what community supports the mothers believe would be helpful.…

  15. 76 FR 68613 - National Adoption Month, 2011

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-04

    ... Sig.) [FR Doc. 2011-28839 Filed 11-3-11; 11:15 am] Billing code 3295-F2-P ... Documents#0;#0; ] Proclamation 8744 of November 1, 2011 National Adoption Month, 2011 By the President of... basic support, and still more children abroad live without families. During National Adoption Month,...

  16. 78 FR 66609 - National Adoption Month, 2013

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-05

    .... (Presidential Sig.) [FR Doc. 2013-26669 Filed 11-4-13; 11:15 am] Billing code 3295-F4 ... Documents#0;#0; ] Proclamation 9049 of October 31, 2013 National Adoption Month, 2013 By the President of... million children and teenagers. During National Adoption Month, we celebrate these families and...

  17. 77 FR 66517 - National Adoption Month, 2012

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-06

    ... Sig.) [FR Doc. 2012-27190 Filed 11-5-12; 8:45 am] Billing code 3295-F3 ... Documents#0;#0; ] Proclamation 8896 of November 1, 2012 National Adoption Month, 2012 By the President of... knowing the love and protection of a permanent family. During National Adoption Month, we give voice...

  18. Covering Adoption: General Depictions in Broadcast News

    ERIC Educational Resources Information Center

    Kline, Susan L.; Karel, Amanda I.; Chatterjee, Karishma

    2006-01-01

    Using theories of stigma (Goffman, 1963) and media frames (Iyengar, 1991), 292 news stories pertaining to adoption that appeared on major broadcast networks between 2001 and 2004 were analyzed. Media coverage of adoptees contained more problematic than positive depictions. Although birth parents were not always depicted, adoptive parent and…

  19. Predicting Language Outcomes for Internationally Adopted Children

    ERIC Educational Resources Information Center

    Glennen, Sharon L.

    2007-01-01

    Purpose: Language and speech are difficult to assess in newly arrived internationally adopted children. The purpose of this study was to determine if assessments completed when toddlers were first adopted could predict language outcomes at age 2. Local norms were used to develop early intervention guidelines that were evaluated against age 2…

  20. States Adopt Standards at Fast Clip

    ERIC Educational Resources Information Center

    Gewertz, Catherine

    2010-01-01

    Nearly half the states have adopted a new set of common academic standards, barely a month after their final release and, in most cases, with little opposition. As of July 9, 23 states had decided to replace their mathematics and English/language arts standards with the common set. Another flurry of adoptions is expected by Aug. 2, since the $4…

  1. Adoption of Improved Agricultural Practices in Uruguay.

    ERIC Educational Resources Information Center

    Rucks, Carlos Alberto

    Conducted in Uruguay during 1965-68, this study compared adoption rates for selected agricultural practices between one area which received an extension program and one which did not; and sought relationships between selected characteristics of individual farmers and the adoption of new practices. Data came from interviews with 69 experimental and…

  2. Fuzzy Cognitive Map Modelling Educational Software Adoption

    ERIC Educational Resources Information Center

    Hossain, Sarmin; Brooks, Laurence

    2008-01-01

    Educational software adoption across UK secondary schools is seen as unsatisfactory. Based on stakeholders' perceptions, this paper uses fuzzy cognitive maps (FCMs) to model this adoption context. It discusses the development of the FCM model, using a mixed-methods approach and drawing on participants from three UK secondary schools. The study…

  3. Why Wasn't This Child Adopted?

    ERIC Educational Resources Information Center

    Raspberry, William

    1982-01-01

    Critizes the public child care policy with regard to adoption services through the story of "Joey", a black child in his teens. Shortly after his birth, Joey was sent by his teenage mother to a city agency for adoption and until now no real effort has been made to place him in a permanent home. (Author/MP)

  4. Nurturing Development of Foster and Adopted Children

    ERIC Educational Resources Information Center

    Nowak-Fabrykowski, Krystyna Teresa

    2015-01-01

    The goal of this study is to investigate early childhood teachers' perspective of teaching foster and adopted children. The main purpose is to seek suggestions how teachers can nurture the development of foster and adopted children. A 6 question survey was sent to 44 teachers pursuing graduate studies in early childhood education. Of this 50%…

  5. Issues in Adoption and Foster Care.

    ERIC Educational Resources Information Center

    Hepworth, H. Philip

    This speech presents an overview of issues and trends in the provision of foster care and adoption services in Canada. The number of children "in care" in Canada (in foster homes, institutions, or adoptive homes) appears to have peaked around 1969 and declined thereafter. Information on contraceptives and the availaibility of abortions are seen as…

  6. A Research and Development Adoption Model

    ERIC Educational Resources Information Center

    Hull, Ronald E.

    1974-01-01

    An elaboration of the adoption phase of the Clark and Guba R and D model. A brief discussion of the normative structures of the organizations and organizational boundary permeability provides the rationale for a set of suggested procedures for adoption of innovations at the school building level. (Author)

  7. Predictors of Adopting Motivational Enhancement Therapy

    ERIC Educational Resources Information Center

    Ager, Richard; Roahen-Harrison, Stephanie; Toriello, Paul J.; Kissinger, Patricia; Morse, Patricia; Morse, Edward; Carney, Linton; Rice, Janet

    2011-01-01

    Substance abuse counselors have shown limited success in adopting evidence-based practices (EBPs). The purpose of this paper is to identify the barriers and facilitators of adopting an EBP called motivational enhancement therapy (MET). One hundred thirty-six predominantly female (60%) African American (68%) addiction counselors representing over…

  8. Conservation Tillage: Monitoring Adoption with Satellite Imagery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation tillage is a commonly adopted best management practice for improving soil quality and reducing erosion. However, there are currently no methods in place to monitor conservation tillage adoption at the watershed scale. The primary objective of this study was to evaluate the utility of ...

  9. Design and synthesis of simplified taxol analogs based on the T-Taxol bioactive conformation

    PubMed Central

    Zhao, Jielu; Bane, Susan; Snyder, James P.; Hu, Haipeng; Mukherjee, Kamalika; Slebodnick, Carla; Kingston, David G. I.

    2011-01-01

    A series of compounds designed to adopt a conformation similar to the tubulin-binding T-Taxol conformation of the anticancer drug paclitaxel has been synthesized. Both the internally bridged analogs 37-39, 41 and the open-chain analogs 27-29 and 43 were prepared. The bridged analogs 37-39 and 41 were synthesized by Grubbs' metatheses of compounds 30-32 and 33, which, in turn, were prepared by coupling β-lactams 24-26 with alcohols 22 and 23. Both the bridged and the open-chain analogs showed moderate to good cytotoxicity. PMID:22071526

  10. Equilibrium and shear-induced conformations of a side-chain liquid crystal polymer

    NASA Astrophysics Data System (ADS)

    Castelletto, V.; Noirez, L.; Vigoureux, P.

    2000-11-01

    These studies delineate the conformations adopted by a side-chain liquid-crystalline polymer subjected to a steady-state shear flow as well as the corresponding me so pha se director orientations. Two distinct director orientations are identified in the nematic phase, giving evidence of a shear-induced transition from a flow-aligning to a non flow-aligning behavior. This transition coincides, at rest, with a subtle change from prolate to oblate polymer main-chain conformation. In the smectic phase, the layers form multilayer cylinders oriented along the velocity axis.

  11. Insights into How Cyclic Peptides Switch Conformations.

    PubMed

    McHugh, Sean M; Rogers, Julia R; Yu, Hongtao; Lin, Yu-Shan

    2016-05-10

    Cyclic peptides have recently emerged as promising modulators of protein-protein interactions. However, it is currently highly difficult to predict the structures of cyclic peptides owing to their rugged conformational free energy landscape, which prevents sampling of all thermodynamically relevant conformations. In this article, we first investigate how a relatively flexible cyclic hexapeptide switches conformations. It is found that, although the circular geometry of small cyclic peptides of size 6-8 may require rare, coherent dihedral changes to sample a new conformation, the changes are rather local, involving simultaneous changes of ϕi and ψi or ψi and ϕi+1. The understanding of how these cyclic peptides switch conformations enables the use of metadynamics simulations with reaction coordinates specifically targeting such coupled two-dihedral changes to effectively sample cyclic peptide conformational space. PMID:27031286

  12. Conformal Electromagnetic Particle in Cell: A Review

    SciTech Connect

    Meierbachtol, Collin S.; Greenwood, Andrew D.; Verboncoeur, John P.; Shanker, Balasubramaniam

    2015-10-26

    We review conformal (or body-fitted) electromagnetic particle-in-cell (EM-PIC) numerical solution schemes. Included is a chronological history of relevant particle physics algorithms often employed in these conformal simulations. We also provide brief mathematical descriptions of particle-tracking algorithms and current weighting schemes, along with a brief summary of major time-dependent electromagnetic solution methods. Several research areas are also highlighted for recommended future development of new conformal EM-PIC methods.

  13. Evolutionary Conserved Positions Define Protein Conformational Diversity.

    PubMed

    Saldaño, Tadeo E; Monzon, Alexander M; Parisi, Gustavo; Fernandez-Alberti, Sebastian

    2016-03-01

    Conformational diversity of the native state plays a central role in modulating protein function. The selection paradigm sustains that different ligands shift the conformational equilibrium through their binding to highest-affinity conformers. Intramolecular vibrational dynamics associated to each conformation should guarantee conformational transitions, which due to its importance, could possibly be associated with evolutionary conserved traits. Normal mode analysis, based on a coarse-grained model of the protein, can provide the required information to explore these features. Herein, we present a novel procedure to identify key positions sustaining the conformational diversity associated to ligand binding. The method is applied to an adequate refined dataset of 188 paired protein structures in their bound and unbound forms. Firstly, normal modes most involved in the conformational change are selected according to their corresponding overlap with structural distortions introduced by ligand binding. The subspace defined by these modes is used to analyze the effect of simulated point mutations on preserving the conformational diversity of the protein. We find a negative correlation between the effects of mutations on these normal mode subspaces associated to ligand-binding and position-specific evolutionary conservations obtained from multiple sequence-structure alignments. Positions whose mutations are found to alter the most these subspaces are defined as key positions, that is, dynamically important residues that mediate the ligand-binding conformational change. These positions are shown to be evolutionary conserved, mostly buried aliphatic residues localized in regular structural regions of the protein like β-sheets and α-helix. PMID:27008419

  14. Computing conformational free energy by deactivated morphing.

    SciTech Connect

    Park, S.; Lau, A. Y.; Roux, B.; Univ. of Chicago

    2008-10-07

    Despite the significant advances in free-energy computations for biomolecules, there exists no general method to evaluate the free-energy difference between two conformations of a macromolecule that differ significantly from each other. A crucial ingredient of such a method is the ability to find a path between different conformations that allows an efficient computation of the free energy. In this paper, we introduce a method called 'deactivated morphing', in which one conformation is morphed into another after the internal interactions are completely turned off. An important feature of this method is the (shameless) use of nonphysical paths, which makes the method robustly applicable to conformational changes of arbitrary complexity.

  15. Evolutionary Conserved Positions Define Protein Conformational Diversity

    PubMed Central

    Saldaño, Tadeo E.; Monzon, Alexander M.; Parisi, Gustavo; Fernandez-Alberti, Sebastian

    2016-01-01

    Conformational diversity of the native state plays a central role in modulating protein function. The selection paradigm sustains that different ligands shift the conformational equilibrium through their binding to highest-affinity conformers. Intramolecular vibrational dynamics associated to each conformation should guarantee conformational transitions, which due to its importance, could possibly be associated with evolutionary conserved traits. Normal mode analysis, based on a coarse-grained model of the protein, can provide the required information to explore these features. Herein, we present a novel procedure to identify key positions sustaining the conformational diversity associated to ligand binding. The method is applied to an adequate refined dataset of 188 paired protein structures in their bound and unbound forms. Firstly, normal modes most involved in the conformational change are selected according to their corresponding overlap with structural distortions introduced by ligand binding. The subspace defined by these modes is used to analyze the effect of simulated point mutations on preserving the conformational diversity of the protein. We find a negative correlation between the effects of mutations on these normal mode subspaces associated to ligand-binding and position-specific evolutionary conservations obtained from multiple sequence-structure alignments. Positions whose mutations are found to alter the most these subspaces are defined as key positions, that is, dynamically important residues that mediate the ligand-binding conformational change. These positions are shown to be evolutionary conserved, mostly buried aliphatic residues localized in regular structural regions of the protein like β-sheets and α-helix. PMID:27008419

  16. Conformation of liquid N-alkanes.

    PubMed Central

    Goodsaid-Zalduondo, F; Engelman, D M

    1981-01-01

    The conformations of liquid n-alkanes have been studied using neutron scattering techniques to better understand the conformational forces present in membrane lipid interiors. We have studied hydrocarbon chains having lengths comparable to those found for esterified membrane lipid fatty acids, and find that the steric constraints of packing in the liquid state do not change the conformational distributions of hydrocarbon chains from those imposed by the intrachain forces present in the gas phase. It follows that the central region of membranes containing lipids in the disordered state should contain hydrocarbon chain conformations determined primarily by intrachain forces. PMID:7272453

  17. Fabrication challenges associated with conformal optics

    NASA Astrophysics Data System (ADS)

    Schaefer, John; Eichholtz, Richard A.; Sulzbach, Frank C.

    2001-09-01

    A conformal optic is typically an optical window that conforms smoothly to the external shape of a system platform to improve aerodynamics. Conformal optics can be on-axis, such as an ogive missile dome, or off-axis, such as in a free form airplane wing. A common example of conformal optics is the automotive head light window that conforms to the body of the car aerodynamics and aesthetics. The unusual shape of conformal optics creates tremendous challenges for design, manufacturing, and testing. This paper will discuss fabrication methods that have been successfully demonstrated to produce conformal missile domes and associated wavefront corrector elements. It will identify challenges foreseen with more complex free-form configurations. Work presented in this paper was directed by the Precision Conformal Optics Consortium (PCOT). PCOT is comprised of both industrial and academic members who teamed to develop and demonstrate conformal optical systems suitable for insertion into future military programs. The consortium was funded under DARPA agreement number MDA972-96-9-08000.

  18. Rotational Spectroscopy Unveils Eleven Conformers of Adrenaline

    NASA Astrophysics Data System (ADS)

    Cabezas, C.; Cortijo, V.; Mata, S.; Lopez, J. C.; Alonso, J. L.

    2013-06-01

    Recent improvements in our LA-MB-FTMW instrumentation have allowed the characterization of eleven and eight conformers for the neurotransmitters adrenaline and noradrenaline respectively. The observation of this rich conformational behavior is in accordance with the recent observation of seven conformers for dopamine and in sharp contrast with the conformational reduction proposed for catecholamines. C. Cabezas, I. Peña, J. C. López, J. L. Alonso J. Phys. Chem. Lett. 2013, 4, 486. H. Mitsuda, M. Miyazaki, I. B. Nielsen, P. Carcabal,C. Dedonder, C. Jouvet, S. Ishiuchi, M. Fujii J. Phys. Chem. Lett. 2010, 1, 1130.

  19. Logarithmic operators and logarithmic conformal field theories

    NASA Astrophysics Data System (ADS)

    Gurarie, Victor

    2013-12-01

    Logarithmic operators and logarithmic conformal field theories are reviewed. Prominent examples considered here include c = -2 and c = 0 logarithmic conformal field theories. c = 0 logarithmic conformal field theories are especially interesting since they describe some of the critical points of a variety of longstanding problems involving a two dimensional quantum particle moving in a spatially random potential, as well as critical two dimensional self-avoiding random walks and percolation. Lack of classification of logarithmic conformal field theories remains a major impediment to progress towards finding complete solutions to these problems.

  20. Conformable eddy current array delivery

    NASA Astrophysics Data System (ADS)

    Summan, Rahul; Pierce, Gareth; Macleod, Charles; Mineo, Carmelo; Riise, Jonathan; Morozov, Maxim; Dobie, Gordon; Bolton, Gary; Raude, Angélique; Dalpé, Colombe; Braumann, Johannes

    2016-02-01

    The external surface of stainless steel containers used for the interim storage of nuclear material may be subject to Atmospherically Induced Stress Corrosion Cracking (AISCC). The inspection of such containers poses a significant challenge due to the large quantities involved; therefore, automating the inspection process is of considerable interest. This paper reports upon a proof-of-concept project concerning the automated NDT of a set of test containers containing artificially generated AISCCs. An Eddy current array probe with a conformable padded surface from Eddyfi was used as the NDT sensor and end effector on a KUKA KR5 arc HW robot. A kinematically valid cylindrical raster scan path was designed using the KUKA|PRC path planning software. Custom software was then written to interface measurement acquisition from the Eddyfi hardware with the motion control of the robot. Preliminary results and analysis are presented from scanning two canisters.

  1. Conformal frame dependence of inflation

    NASA Astrophysics Data System (ADS)

    Domènech, Guillem; Sasaki, Misao

    2015-04-01

    Physical equivalence between different conformal frames in scalar-tensor theory of gravity is a known fact. However, assuming that matter minimally couples to the metric of a particular frame, which we call the matter Jordan frame, the matter point of view of the universe may vary from frame to frame. Thus, there is a clear distinction between gravitational sector (curvature and scalar field) and matter sector. In this paper, focusing on a simple power-law inflation model in the Einstein frame, two examples are considered; a super-inflationary and a bouncing universe Jordan frames. Then we consider a spectator curvaton minimally coupled to a Jordan frame, and compute its contribution to the curvature perturbation power spectrum. In these specific examples, we find a blue tilt at short scales for the super-inflationary case, and a blue tilt at large scales for the bouncing case.

  2. Approaching Conformality with Ten Flavors

    SciTech Connect

    Appelquist, Thomas; Brower, Richard C.; Buchoff, Michael I.; Cheng, Michael; Cohen, Saul D.; Fleming, George T.; Kiskis, Joe; Lin, Meifeng; Na, Heechang; Neil, Ethan T.; Osborn, James C.

    2012-04-01

    We present first results for lattice simulations, on a single volume, of the low-lying spectrum of an SU(3) Yang-Mills gauge theory with N{sub f} = 10 light fermions in the fundamental representation. Fits to the fermion mass dependence of various observables are found to be globally consistent with the hypothesis that this theory is within or just outside the strongly-coupled edge of the conformal window, with mass anomalous dimension {gamma}* {approx} 1 over the range of scales simulated. We stress that we cannot rule out the possibility of spontaneous chiral-symmetry breaking at scales well below our infrared cutoff. We discuss important systematic effects, including finite-volume corrections, and consider directions for future improvement.

  3. Electromagnetic characterization of conformal antennas

    NASA Technical Reports Server (NTRS)

    Volakis, John L.; Kempel, Leo C.; Alexanian, Angelos; Jin, J. M.; Yu, C. L.; Woo, Alex C.

    1992-01-01

    The ultimate objective of this project is to develop a new technique which permits an accurate simulation of microstrip patch antennas or arrays with various feed, superstrate and/or substrate configurations residing in a recessed cavity whose aperture is planar, cylindrical or otherwise conformed to the substructure. The technique combines the finite element and boundary integral methods to formulate a system suitable for solution via the conjugate gradient method in conjunction with the fast Fourier transform. The final code is intended to compute both scattering and radiation patterns of the structure with an affordable memory demand. With upgraded capabilities, the four included papers examined the radar cross section (RCS), input impedance, gain, and resonant frequency of several rectangular configurations using different loading and substrate/superstrate configurations.

  4. Conformal approach to cylindrical DLA

    NASA Astrophysics Data System (ADS)

    Taloni, A.; Caglioti, E.; Loreto, V.; Pietronero, L.

    2006-09-01

    We extend the conformal mapping approach elaborated for the radial diffusion limited aggregation model (DLA) to cylindrical geometry. We introduce in particular a complex function which allows a cylindrical cluster to be grown using as an intermediate step a radial aggregate. The aggregate grown exhibits the same self-affine features as the original cylindrical DLA. The specific choice of the transformation allows us to study the relationship between the radial and the cylindrical geometry. In particular the cylindrical aggregate can be seen as a radial aggregate with particles of size increasing with the radius. On the other hand, the radial aggregate can be seen as a cylindrical aggregate with particles of size decreasing with the height. This framework, which shifts the point of view from the geometry to the size of the particles, can open the way to more quantitative studies on the relationship between radial and cylindrical DLA.

  5. Substrate-Induced Conformational Changes Occur in All Cleaved Forms of Caspase-6

    SciTech Connect

    S Vaidya; E Velazquez-Delgado; G Abbruzzese; J Hardy

    2011-12-31

    Caspase-6 is an apoptotic cysteine protease that also governs disease progression in Huntington's and Alzheimer's diseases. Caspase-6 is of great interest as a target for treatment of these neurodegenerative diseases; however, the molecular basis of caspase-6 function and regulation remains poorly understood. In the recently reported structure of caspase-6, the 60's and 130's helices at the base of the substrate-binding groove extend upward, in a conformation entirely different from that of any other caspase. Presently, the central question about caspase-6 structure and function is whether the extended conformation is the catalytically competent conformation or whether the extended helices must undergo a large conformational rearrangement in order to bind substrate. We have generated a series of caspase-6 cleavage variants, including a novel constitutively two-chain form, and determined crystal structures of caspase-6 with and without the intersubunit linker. This series allows evaluation of the role of the prodomain and intersubunit linker on caspase-6 structure and function before and after substrate binding. Caspase-6 is inherently more stable than closely related caspases. Cleaved caspase-6 with both the prodomain and the linker present is the most stable, indicating that these two regions act in concert to increase stability, but maintain the extended conformation in the unliganded state. Moreover, these data suggest that caspase-6 undergoes a significant conformational change upon substrate binding, adopting a structure that is more like canonical caspases.

  6. Substrate-induced conformational changes occur in all cleaved forms of caspase-6

    PubMed Central

    Vaidya, Sravanti; Velázquez-Delgado, Elih M.; Abbruzzese, Genevieve; Hardy, Jeanne A.

    2010-01-01

    Caspase-6 is an apoptotic cysteine protease that also governs disease progression in Huntington’s and Alzheimer’s Diseases. Caspase-6 is of great interest as a target for treatment of these neurodegenerative diseases, however the molecular basis of caspase-6 function and regulation remains poorly understood. In the recently reported structure of caspase-6, the 60’s and 130’s helices at the base of the substrate-binding groove extend upward, in a conformation entirely different from that of any other caspase. Presently, the central question about caspase-6 structure and function is whether the extended conformation is the catalytically competent conformation or whether the extended helices must undergo a large conformational rearrangement in order to bind substrate. We have generated a series of caspase-6 cleavage variants including a novel constitutively two-chain form and determined crystal structures of caspase-6 with and without the intersubunit linker. This series allows evaluation of the role of the prodomain and intersubunit linker on caspase-6 structure and function before and after substrate binding. Caspase-6 is inherently more stable than closely related caspases. Cleaved caspase-6 with both the prodomain and linker present is the most stable indicating that these two regions act in concert to increase stability, but maintain the extended conformation in the unliganded state. Most importantly, these data suggest that caspase-6 undergoes a significant conformational change upon substrate binding, adopting a structure that is more like canonical caspases. PMID:21111746

  7. Molecular dynamics simulations of conformation changes of HIV-1 regulatory protein on graphene

    NASA Astrophysics Data System (ADS)

    Zhao, Daohui; Li, Libo; He, Daohang; Zhou, Jian

    2016-07-01

    The fragment of viral protein R (Vpr), Vpr13-33, plays an important role in regulating nuclear importing of HIV genes through channel formation in which it adopts a leucine-zipper-like alpha-helical conformation. A recent experimental study reported that helical Vpr13-33 would transform to β-sheet or random coil structures and aggregate on the surface of graphene or graphene oxide through hydrophobic interactions. Due to experimental limitations, however, there is still a considerable lack of understanding on the adsorption dynamics at the early stage of the conformational transition at water-graphene interface and the underlying driving force at molecular level. In this study, atomistic molecular dynamics simulations were used to explore the conformation transition phenomena. Vpr13-33 kept α-helical structure in solution, but changed to β-sheet structure when strongly adsorbed onto graphene. Preferential adsorption of Vpr13-33 on graphene is dominated by hydrophobic interactions. The cluster analysis identified the most significant populated conformation and the early stage of structure conversion from α-helical to β-sheet was found, but the full β-sheet propagation was not observed. Free energy landscape analysis further complemented the transformation analysis of peptide conformations. These findings are consistent with experimental results, and give a molecular level interpretation for the reduced cytotoxicity of Vpr13-33 to some extent upon graphene exposure. Meanwhile, this study provides some significant insights into the detailed mechanism of graphene-induced protein conformation transition.

  8. Design of cyclic peptides featuring proline predominantly in the cis conformation under physiological conditions.

    PubMed

    Malešević, Miroslav; Schumann, Michael; Jahreis, Günther; Fischer, Gunter; Lücke, Christian

    2012-09-24

    Turns are secondary-structure elements that are omnipresent in natively folded polypeptide chains. A large variety of four-residue β-turns exist, which differ mainly in the backbone dihedral angle values of the two central residues i+1 and i+2. The βVI-type turns are of particular biological interest because the i+2 residue is always a proline in the cis conformation and might thus serve as target of peptidyl prolyl cis/trans isomerases (PPIases). We have designed cyclic hexapeptides containing two proline residues that predominantly adopt the cis conformation in aqueous solution. NMR data and MD calculations indicated that the cyclic peptide sequences c-(-DXaa-Ser-Pro-DXaa-Lys-Pro-) result in highly symmetric backbone structures when both prolines are in the cis conformation and the D-amino acids are either alanine or phenylalanine residues. Replacement of the serine residue either by phosphoserine or by tyrosine compromises this symmetry, but further increases the cis conformation content of both prolines. As a result, we obtained a cyclic hexapeptide that exists almost exclusively as the cis-Pro/cis-Pro conformer but shows no cis/trans interconversion even in the presence of the PPIase Pin1, apparently due to an energetically quite favorable but highly restricted conformational space. PMID:22969011

  9. Developmental Outcomes of Internationally Adopted Children

    PubMed Central

    Welsh, Janet A.; Viana, Andres G.

    2013-01-01

    This study followed the development of a sample of 106 (67 girls) internationally adopted children over a period of 18 months. Children were adopted from five birth regions, including China, Korea, Latin America, Eastern Europe, and other Asian countries. Mean age at adoption was 11 months. Mothers completed the Ages and Stages Questionnaire (ASQ) at 6, 12, and 24 months post-adoption, assessing children's gross and fine motor, communicative, personal-social, and problem solving skills. Results revealed that the sample as a whole demonstrated linear improvement over time in most developmental domains, but children with initially low scores remained significantly lower than other children at the 18-month follow-up. At the first time point, communication was the domain where children most commonly experienced delays. Children with medical problems had significantly lower developmental scores than those without medical diagnoses. ASQ scores were unrelated to age at adoption, but significant differences by birth country region were found. Across most domains, children adopted from Eastern Europe showed generally lower scores than children adopted from other birth regions. PMID:23908583

  10. 20 CFR 404.733 - Evidence you are the legally adopting parent or legally adopted child.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... needed, evidence of the date of adoption; (b) If the widow or widower adopted the child after the insured... or legally adopted child. 404.733 Section 404.733 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Evidence Evidence for Child's and...

  11. Parallel Process Issues for Lesbian and Gay Adoptive Parents and Their Adopted Children

    ERIC Educational Resources Information Center

    Matthews, John D.; Cramer, Elizabeth P.

    2005-01-01

    Gays and lesbians, both single and coupled, are increasingly turning to adoption to create or expand their families. This manuscript specifically addresses the continuing needs of adoptees and adoptive parents by exploring key issues in the life course of gays and lesbians and their adopted children, and identifying potential parallel development…

  12. Skin Color in Transracial and Inracial Adoptive Placements: Implications for Special Needs Adoptions.

    ERIC Educational Resources Information Center

    McRoy, Ruth G.; Grape, Helen

    1999-01-01

    Explores interview excerpts of African-American adults adopted either transracially or interracially to discuss implications of color for special-needs adoptions. Finds that the issue of color extends beyond racial differences to include skin tone and that children are aware of and internalize color at an early age. Suggests that adoption agencies…

  13. Open Adoption of Infants: Adoptive Parents' Perceptions of Advantages and Disadvantages.

    ERIC Educational Resources Information Center

    Siegel, Deborah H.

    1993-01-01

    Conducted qualitative study of adoptive parents' (n=21 couples) reactions to recent open adoptions of their infants. Findings indicated overwhelmingly positive feelings about open adoption. Respondents often noted that issue of openness was eclipsed by other concerns: coping with infertility, finding a baby, dealing with personnel, and dealing…

  14. Korean Adoptee Identity: Adoptive and Ethnic Identity Profiles of Adopted Korean Americans

    ERIC Educational Resources Information Center

    Beaupre, Adam J.; Reichwald, Reed; Zhou, Xiang; Raleigh, Elizabeth; Lee, Richard M.

    2015-01-01

    Adopted Korean adolescents face the task of grappling with their identity as Koreans and coming to terms with their adoptive status. In order to explore these dual identities, the authors conducted a person-centered study of the identity profiles of 189 adopted Korean American adolescents. Using cluster analytic procedures, the study examined…

  15. Cultural Tourism in Transnational Adoption: "Staged Authenticity" and Its Implications for Adopted Children

    ERIC Educational Resources Information Center

    Quiroz, Pamela Anne

    2012-01-01

    The discursive practices of adoptive parents in two online transnational adoption forums (2006-2008) and observations of five international adoption workshops suggest that what Heather Jacobson described as "culture keeping", the cultural socialization of children that retains a sense of native group identity, is more aptly characterized as…

  16. A Study of Self-Esteem in Adopted Non-adopted Adolescents.

    ERIC Educational Resources Information Center

    Steward, Robbie J.; Lynn, Betty Jane

    This study tested the hypothesis that adopted adolescents have lower self-esteem than do non-adopted adolescents. Male and female students (N=159) between the ages of 18 and 22 were conveniently sampled from college undergraduate populations. Forty-four of the participants reported adoptive status. Each participant completed the Coopersmith…

  17. Pricing Health Behavior Interventions to Promote Adoption

    PubMed Central

    Ribisl, Kurt M.; Leeman, Jennifer; Glasser, Allison M.

    2015-01-01

    The relatively high cost of delivering many public health interventions limits their potential for broad public impact by reducing their likelihood of adoption and maintenance over time. Practitioners identify cost as the primary factor for which interventions they select to implement, but researchers rarely disseminate cost information or consider its importance when developing new interventions. A new approach is proposed, whereby intervention developers assess what individuals and agencies adopting their interventions are willing to pay and then design interventions that are responsive to this price range. The ultimate goal is to develop effective and affordable interventions, called lean interventions, which are widely adopted and have greater public health impact. PMID:24842743

  18. Populations of the Minor α-Conformation in AcGXGNH2 and the α-Helical Nucleation Propensities

    NASA Astrophysics Data System (ADS)

    Zhou, Yanjun; He, Liu; Zhang, Wenwen; Hu, Jingjing; Shi, Zhengshuang

    2016-06-01

    Intrinsic backbone conformational preferences of different amino acids are important for understanding the local structure of unfolded protein chains. Recent evidence suggests α-structure is relatively minor among three major backbone conformations for unfolded proteins. The α-helices are the dominant structures in many proteins. For these proteins, how could the α-structures occur from the least in unfolded to the most in folded states? Populations of the minor α-conformation in model peptides provide vital information. Reliable determination of populations of the α-conformers in these peptides that exist in multiple equilibriums of different conformations remains a challenge. Combined analyses on data from AcGXPNH2 and AcGXGNH2 peptides allow us to derive the populations of PII, β and α in AcGXGNH2. Our results show that on average residue X in AcGXGNH2 adopt PII, β, and α 44.7%, 44.5% and 10.8% of time, respectively. The contents of α-conformations for different amino acids define an α-helix nucleation propensity scale. With derived PII, β and α-contents, we can construct a free energy-conformation diagram on each AcGXGNH2 in aqueous solution for the three major backbone conformations. Our results would have broad implications on early-stage events of protein folding.

  19. Populations of the Minor α-Conformation in AcGXGNH2 and the α-Helical Nucleation Propensities

    PubMed Central

    Zhou, Yanjun; He, Liu; Zhang, Wenwen; Hu, Jingjing; Shi, Zhengshuang

    2016-01-01

    Intrinsic backbone conformational preferences of different amino acids are important for understanding the local structure of unfolded protein chains. Recent evidence suggests α-structure is relatively minor among three major backbone conformations for unfolded proteins. The α-helices are the dominant structures in many proteins. For these proteins, how could the α-structures occur from the least in unfolded to the most in folded states? Populations of the minor α-conformation in model peptides provide vital information. Reliable determination of populations of the α-conformers in these peptides that exist in multiple equilibriums of different conformations remains a challenge. Combined analyses on data from AcGXPNH2 and AcGXGNH2 peptides allow us to derive the populations of PII, β and α in AcGXGNH2. Our results show that on average residue X in AcGXGNH2 adopt PII, β, and α 44.7%, 44.5% and 10.8% of time, respectively. The contents of α-conformations for different amino acids define an α-helix nucleation propensity scale. With derived PII, β and α-contents, we can construct a free energy-conformation diagram on each AcGXGNH2 in aqueous solution for the three major backbone conformations. Our results would have broad implications on early-stage events of protein folding. PMID:27256621

  20. Internationally Adopted Children: Important Information for Parents

    MedlinePlus

    ... iodine). Newborn metabolic screen up to 2 years. Infectious Diseases PPD or currently recommended testing for tuberculosis exposure ( ... Pediatrics. Medical Evaluation of Internationally Adopted Children for Infectious Diseases. In: Pickering LK, Baker CJ, Kimberlin DW, Long SS, ...

  1. Distributed PV Adoption in Maine Through 2021

    SciTech Connect

    Gagnon, Pieter; Sigrin, Ben

    2015-11-06

    NREL has used its dSolar (distributed solar) model to generate low-medium-high estimates of distributed PV adoption in Maine through 2021. This presentation gives a high-level overview of the model and modeling results.

  2. Drivers and Barriers in Health IT Adoption

    PubMed Central

    Avgar, A.C.; Litwin, A.S.; Pronovost, P.J.

    2012-01-01

    Despite near (and rare) consensus that the adoption and diffusion of health information technology (health IT) will bolster outcomes for organizations, individuals, and the healthcare system as a whole, there has been surprisingly little consideration of the structures and processes within organizations that might drive the adoption and effective use of the technology. Management research provides a useful lens through which to analyze both the determinants of investment and the benefits that can ultimately be derived from these investments. This paper provides a conceptual framework for understanding health IT adoption. In doing so, this paper highlights specific organizational barriers or enablers at different stages of the adoption process – investment, implementation, and use – and at different levels of organizational decision-making – strategic, operational, and frontline. This framework will aid both policymakers and organizational actors as they make sense of the transition from paper-based to electronic systems. PMID:23646093

  3. Are You Pregnant and Thinking about Adoption?

    MedlinePlus

    ... stories . O.J. Howard Publishing. Siegel, D.H., & Smith, S.L. (2012). Openness in adoption: From secrecy and ... from- secrecy- and- stigma- to- knowledge- and- connections/ Smith, S. (2007). Safeguarding the rights and well-being of ...

  4. Adopting Integrated Pest Management in Schools.

    ERIC Educational Resources Information Center

    Currie, William E.

    1991-01-01

    The development of an effective Integrated Pest Management program is discussed. Provided are the common goals and procedures involved in adopting an Integrated Pest Management program for schools. (CW)

  5. Disparities in Primary Care EHR Adoption Rates

    PubMed Central

    Mack, Dominic; Zhang, Shun; Douglas, Megan; Sow, Charles; Strothers, Harry; Rust, George

    2016-01-01

    This study evaluates electronic health record (EHR) adoption by primary care providers in Georgia to assess adoption disparities according to practice size and type, payer mix, and community characteristics. Frequency variances of EHR “Go Live” status were estimated. Odds ratios were calculated by univariate and multivariate logistic regression models. Large practices and community health centers (CHCs) were more likely to Go Live (>80% EHR adoption) than rural health clinics and other underserved settings (53%). A significantly lower proportion (68.9%) of Medicaid predominant providers had achieved Go Live status and had a 47% higher risk of not achieving Go Live status than private insurance predominant practices. Disparities in EHR adoption rates may exacerbate existing disparities in health outcomes of patients served by these practices. Targeted support such as that provided to CHCs would level the playing field for practices now at a disadvantage. PMID:27587942

  6. Intercountry Adoption and the Family Life Cycle.

    ERIC Educational Resources Information Center

    Deacon, Sharon A.

    1997-01-01

    Provides family therapists with an understanding of intercountry adoption. The special life-cycle issues of multinational families and the challenges intercountry adoptees face are discussed to help therapists treat such families more empathically and effectively. (Author/MKA)

  7. Parental Bonding in Older-Child Adoptions.

    ERIC Educational Resources Information Center

    Ward, Margaret

    1981-01-01

    Examines various factors (such as periods of high emotion, ritual and claiming behaviors and positive interaction) in the attachment process between adoptive parents and older children. Shows that most components parallel those of bonding in biological parents. (Author/RH)

  8. [The outcomes of Adoption in the Case of the "British Chinese Adoption Study"].

    PubMed

    Rushton, Alan

    2015-01-01

    Practitioners can over-estimate the incidence of problems in adopted children and adults because they do not see those who make good psychological and social adjustments. Research into adoption outcomes can be hard to interpret without information about differing pre-adoption histories. Examples are given of research into three types of adoption: domestic infant adoption, adoptions from public care of maltreated children and international adoption of ex-orphanage children. Although negative outcomes are indisputably evident for some, recovery from adversity is more common than many would predict. It is important to recognize that subsequent nurturing in consistent and stimulating environments can build a platform for effective adaptations to challenges in the future. However, a proper understanding of the consequences of adoption has been limited by the fact that follow-up studies have rarely extended beyond adolescence and early adulthood. The British Chinese Adoption Study is a 50 year follow-up of orphanage girls internationally adopted into the United Kingdom, and is given as an example of good outcomes despite early years of adversity. Scores on mental health assessments were equivalent to the non-adopted, age-matched comparison group of UK women. Most of the women were rated as "good functioning" and educational achievements were many times higher than the comparison women. Life-long adverse effects are not inevitable following early adversity. Improved circumstances can promote recovery and good adult adjustment. Practice and research implications are discussed. PMID:26645770

  9. Psychological Ramifications of Adoption and Implications for Counseling.

    ERIC Educational Resources Information Center

    Helwig, Andrew A.; Ruthven, Dorothy H.

    1990-01-01

    Examines adoption issues including family member loss, infertility, transracial adoptions, special-needs adoptions, older child adoption, inherited traits, adoptive family, biological parents, and open adoption. Suggests specific therapeutic interventions including redefinition, use of paradox, family therapy approaches, group therapy, and…

  10. 5 CFR 843.404 - Proof of adoption.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Proof of adoption. 843.404 Section 843... Proof of adoption. (a) An adopted child is— (1) A child adopted by the employee or retiree before the... petition for adoption was filed by the employee or retiree and who is adopted by the current spouse of...

  11. 5 CFR 843.404 - Proof of adoption.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Proof of adoption. 843.404 Section 843... Proof of adoption. (a) An adopted child is— (1) A child adopted by the employee or retiree before the... petition for adoption was filed by the employee or retiree and who is adopted by the current spouse of...

  12. 5 CFR 843.404 - Proof of adoption.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Proof of adoption. 843.404 Section 843... Proof of adoption. (a) An adopted child is— (1) A child adopted by the employee or retiree before the... petition for adoption was filed by the employee or retiree and who is adopted by the current spouse of...

  13. Adoption Activities on the Internet: A Call for Regulation

    ERIC Educational Resources Information Center

    Roby, Jini L.; White, Holly

    2010-01-01

    There is a growing practice of adoption services on the Internet with varying degrees of regulation, depending on whether it is domestic infant adoption, public foster care adoption, or international adoption. Regulation is particularly lacking in domestic infant adoptions, with Web sites connecting prospective birth and adoptive parents,…

  14. 5 CFR 843.404 - Proof of adoption.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Proof of adoption. 843.404 Section 843... Proof of adoption. (a) An adopted child is— (1) A child adopted by the employee or retiree before the... petition for adoption was filed by the employee or retiree and who is adopted by the current spouse of...

  15. 5 CFR 843.404 - Proof of adoption.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 2 2014-01-01 2014-01-01 false Proof of adoption. 843.404 Section 843... Proof of adoption. (a) An adopted child is— (1) A child adopted by the employee or retiree before the... petition for adoption was filed by the employee or retiree and who is adopted by the current spouse of...

  16. Moses and Superman Come Home: Counseling Adoptees and Adoptive Families.

    ERIC Educational Resources Information Center

    Saiz, Stephen G.

    This paper looks at three parties impacted by adoption: the adoptive parents, the adopted child, and the adoptive family. When working with adoptive parents, counselors should respect the strength of the couple, their commitment to parenthood, and the closeness that may develop from weathering the issue of childlessness. Adoptive parents are…

  17. The Practice of Adoption: History, Trends, and Social Context

    ERIC Educational Resources Information Center

    Zamostny, Kathy P.; O'Brien, Karen M.; Baden, Amanda L.; Wiley, Mary O'Leary

    2003-01-01

    This article presents an overview of the practice of adoption to counseling psychologists to promote clinical understanding of the adoption experience and to stimulate research on adoption. The article includes definitions of adoption terminology, important historical and legal developments for adoption, a summary of adoption statistics,…

  18. Better Informed Distance Geometry: Using What We Know To Improve Conformation Generation.

    PubMed

    Riniker, Sereina; Landrum, Gregory A

    2015-12-28

    Small organic molecules are often flexible, i.e., they can adopt a variety of low-energy conformations in solution that exist in equilibrium with each other. Two main search strategies are used to generate representative conformational ensembles for molecules: systematic and stochastic. In the first approach, each rotatable bond is sampled systematically in discrete intervals, limiting its use to molecules with a small number of rotatable bonds. Stochastic methods, on the other hand, sample the conformational space of a molecule randomly and can thus be applied to more flexible molecules. Different methods employ different degrees of experimental data for conformer generation. So-called knowledge-based methods use predefined libraries of torsional angles and ring conformations. In the distance geometry approach, on the other hand, a smaller amount of empirical information is used, i.e., ideal bond lengths, ideal bond angles, and a few ideal torsional angles. Distance geometry is a computationally fast method to generate conformers, but it has the downside that purely distance-based constraints tend to lead to distorted aromatic rings and sp(2) centers. To correct this, the resulting conformations are often minimized with a force field, adding computational complexity and run time. Here we present an alternative strategy that combines the distance geometry approach with experimental torsion-angle preferences obtained from small-molecule crystallographic data. The torsional angles are described by a previously developed set of hierarchically structured SMARTS patterns. The new approach is implemented in the open-source cheminformatics library RDKit, and its performance is assessed by comparing the diversity of the generated ensemble and the ability to reproduce crystal conformations taken from the crystal structures of small molecules and protein-ligand complexes. PMID:26575315

  19. The conformational properties of α,β-dehydroamino acids with a C-terminal ester group.

    PubMed

    Siodłak, Dawid; Grondys, Justyna; Broda, Małgorzata A

    2011-10-01

    α,β-Dehydroamino acid esters occur in nature. To investigate their conformational properties, a systematic theoretical analysis was performed on the model molecules Ac-ΔXaa-OMe [ΔXaa = ΔAla, (E)-ΔAbu, (Z)-ΔAbu, ΔVal] at the B3LYP/6-311+ + G(d,p) level in the gas phase as well as in chloroform and water solutions with the self-consistent reaction field-polarisable continuum model method. The Fourier transform IR spectra in CCl(4) and CHCl(3) have been analysed as well as the analogous solid state conformations drawn from The Cambridge Structural Database. The ΔAla residue has a considerable tendency to adopt planar conformations C5 (ϕ, ψ ≈ - 180°, 180°) and β2 (ϕ, ψ ≈ - 180°, 0°), regardless of the environment. The ΔVal residue prefers the conformation β2 (ϕ, ψ ≈ - 120°, 0°) in a low polar environment, but the conformations α (ϕ, ψ ≈ - 55°, 35°) and β (ϕ, ψ ≈ - 55°, 145°) when the polarity increases. The ΔAbu residues reveal intermediate properties, but their conformational dispositions depend on configuration of the side chain of residue: (E)-ΔAbu is similar to ΔAla, whereas (Z)-ΔAbu to ΔVal. Results indicate that the low-energy conformation β2 is the characteristic feature of dehydroamino acid esters. The studied molecules constitute conformational patterns for dehydroamino acid esters with various side chain substituents in either or both Z and E positions. PMID:21805538

  20. Conformity to Peer Pressure in Preschool Children

    ERIC Educational Resources Information Center

    Haun, Daniel B. M.; Tomasello, Michael

    2011-01-01

    Both adults and adolescents often conform their behavior and opinions to peer groups, even when they themselves know better. The current study investigated this phenomenon in 24 groups of 4 children between 4;2 and 4;9 years of age. Children often made their judgments conform to those of 3 peers, who had made obviously erroneous but unanimous…

  1. CCProf: exploring conformational change profile of proteins

    PubMed Central

    Chang, Che-Wei; Chou, Chai-Wei; Chang, Darby Tien-Hao

    2016-01-01

    In many biological processes, proteins have important interactions with various molecules such as proteins, ions or ligands. Many proteins undergo conformational changes upon these interactions, where regions with large conformational changes are critical to the interactions. This work presents the CCProf platform, which provides conformational changes of entire proteins, named conformational change profile (CCP) in the context. CCProf aims to be a platform where users can study potential causes of novel conformational changes. It provides 10 biological features, including conformational change, potential binding target site, secondary structure, conservation, disorder propensity, hydropathy propensity, sequence domain, structural domain, phosphorylation site and catalytic site. All these information are integrated into a well-aligned view, so that researchers can capture important relevance between different biological features visually. The CCProf contains 986 187 protein structure pairs for 3123 proteins. In addition, CCProf provides a 3D view in which users can see the protein structures before and after conformational changes as well as binding targets that induce conformational changes. All information (e.g. CCP, binding targets and protein structures) shown in CCProf, including intermediate data are available for download to expedite further analyses. Database URL: http://zoro.ee.ncku.edu.tw/ccprof/ PMID:27016699

  2. Conformational Sampling of Peptides in Cellular Environments☆

    PubMed Central

    Tanizaki, Seiichiro; Clifford, Jacob; Connelly, Brian D.; Feig, Michael

    2008-01-01

    Abstract Biological systems provide a complex environment that can be understood in terms of its dielectric properties. High concentrations of macromolecules and cosolvents effectively reduce the dielectric constant of cellular environments, thereby affecting the conformational sampling of biomolecules. To examine this effect in more detail, the conformational preference of alanine dipeptide, poly-alanine, and melittin in different dielectric environments is studied with computer simulations based on recently developed generalized Born methodology. Results from these simulations suggest that extended conformations are favored over α-helical conformations at the dipeptide level at and below dielectric constants of 5–10. Furthermore, lower-dielectric environments begin to significantly stabilize helical structures in poly-alanine at ɛ = 20. In the more complex peptide melittin, different dielectric environments shift the equilibrium between two main conformations: a nearly fully extended helix that is most stable in low dielectrics and a compact, V-shaped conformation consisting of two helices that is preferred in higher dielectric environments. An additional conformation is only found to be significantly populated at intermediate dielectric constants. Good agreement with previous studies of different peptides in specific, less-polar solvent environments, suggest that helix stabilization and shifts in conformational preferences in such environments are primarily due to a reduced dielectric environment rather than specific molecular details. The findings presented here make predictions of how peptide sampling may be altered in dense cellular environments with reduced dielectric response. PMID:17905846

  3. Regulatory Conformance Checking: Logic and Logical Form

    ERIC Educational Resources Information Center

    Dinesh, Nikhil

    2010-01-01

    We consider the problem of checking whether an organization conforms to a body of regulation. Conformance is studied in a runtime verification setting. The regulation is translated to a logic, from which we synthesize monitors. The monitors are evaluated as the state of an organization evolves over time, raising an alarm if a violation is…

  4. Adoption in the age of reproductive technology.

    PubMed

    van den Akker, O B A

    2001-05-01

    The choice of adoption over genetic parenthood was investigated in 105 women retrospectively by questionnaire. Participants were divided into four groups: female/male subfertility; female subfertility; male subfertility; and female/male fertility. Half the sample (59/105) answered the question about the importance of a genetic link. Women who failed to adopt thought a genetic link was important, as did those who were less likely to disclose alternative reproductive conceptions to their child. First thoughts following diagnosis were more focused and actions more centered on adoption in the female/male subfertile group compared to the other groups. Communication of the child's origins was least prevalent in the female/male subfertile group, followed by the male subfertile group, although all groups would disclose adoption. The choice of adoption was determined by a number of factors, not all associated with infertility resolution. Although it is unlikely that resolution to infertility can be achieved in any population attempting to overcome infertility, the cognitive dissonance identified in this population is likely to be generalizable to those choosing other options to overcome infertility. Cultural and counselling acknowledgement of postmodern family theory principles is likely to ease cognitive consistency regarding the status of adoptive familyhood, and dispel the importance of reproductive options emphasizing a genetic link. PMID:12449936

  5. Assessing access for prospective adoptive parents living with HIV: an environmental scan of Ontario's adoption agencies.

    PubMed

    Underhill, Angela A; Kennedy, V Logan; Lewis, Johanna; Ross, Lori E; Loutfy, Mona

    2016-10-01

    Work has been underway to increase the availability of parenting options for people living with and affected by HIV. One option, adoption, has not yet been explored in the literature. The study aimed to gain a better understanding of the potential of adoption for individuals/couples living with HIV in Ontario, and to assess potential structural barriers or facilitators that may impact their experience navigating the adoption system by conducting an environmental scan of adoption service providers in Ontario. A list of adoption service providers was compiled using the Ontario government's website. Information relevant to the study's measures was collected using service providers' websites. Service providers without websites, or with websites that did not address all of the research measures, were contacted via telephone to complete a structured interview. Online data extraction was possible for 2 and telephone surveys were completed with 75 adoption service providers (total n = 77). Most service providers reported that HIV status is not an exclusion criterion for prospective parents (64%). However, more than one-fifth of the participants acknowledged they were not sure if people with HIV were eligible to adopt. Domestic service providers were the only providers who did not report knowledge of restrictions due to HIV status. Private domestic adoption presented social barriers as birth parent(s) of a child can access health records of a prospective parent and base their selection of an adoptive parent based on health status. Adoption practitioners and licensees involved in international adoptions reported the most structural barriers for prospective parent(s) living with HIV, attributed to the regulations established by the host country of the child(ren) eligible for adoption. Although international adoptions may present insurmountable barriers for individuals living with HIV, public and private domestic adoption appears to be a viable option. PMID:27136971

  6. Technidilaton at the conformal edge

    SciTech Connect

    Hashimoto, Michio; Yamawaki, Koichi

    2011-01-01

    Technidilaton (TD) was proposed long ago in the technicolor near criticality/conformality. To reveal the critical behavior of TD, we explicitly compute the nonperturbative contributions to the scale anomaly <{theta}{sub {mu}}{sup {mu}>} and to the technigluon condensate <{alpha}G{sub {mu}{nu}}{sup 2}>, which are generated by the dynamical mass m of the technifermions. Our computation is based on the (improved) ladder Schwinger-Dyson equation, with the gauge coupling {alpha} replaced by the two-loop running coupling {alpha}({mu}) having the Caswell-Banks-Zaks infrared fixed point {alpha}{sub *}: {alpha}({mu}){approx_equal}{alpha}={alpha}{sub *} for the infrared region m<{mu}<{Lambda}{sub TC}, where {Lambda}{sub TC} is the intrinsic scale (analogue of {Lambda}{sub QCD} of QCD) relevant to the perturbative scale anomaly. We find that -<{theta}{sub {mu}}{sup {mu}}>/m{sup 4}{yields}const{ne}0 and <{alpha}G{sub {mu}}{nu}{sup 2}>/m{sup 4}{yields}({alpha}/{alpha}{sub cr}-1){sup -3/2}{yields}{infinity} in the criticality limit m/{Lambda}{sub TC}{approx}exp(-{pi}/({alpha}/{alpha}{sub cr}-1){sup 1/2}){yields}0 ({alpha}={alpha}{sub *}=>{alpha}{sub cr}, or N{sub f} approaches N{sub f}{sup cr}) ('conformal edge'). Our result precisely reproduces the formal identity <{theta}{sub {mu}}{sup {mu}>}=({beta}({alpha})/4{alpha}{sup 2})<{alpha}G{sub {mu}{nu}}{sup 2}>, where {beta}({alpha})={Lambda}{sub TC}({partial_derivative}{alpha}/{partial_derivative}{Lambda}{sub TC})=-(2{alpha}{sub cr}/{pi}){center_dot}({alpha}/{alpha}{sub cr}-1){sup 3/2} is the nonperturbative beta function corresponding to the above essential singularity scaling of m/{Lambda}{sub TC}. Accordingly, the partially conserved dilatation current implies (M{sub TD}/m){sup 2}(F{sub TD}/m){sup 2}=-4<{theta}{sub {mu}}{sup {mu}}>/m{sup 4}{yields}const{ne}0 at criticality limit, where M{sub TD} is the mass of TD and F{sub TD} the decay constant of TD. We thus conclude that at criticality limit the TD could become a ''true

  7. Reducing spurious gravitational radiation in binary-black-hole simulations by using conformally curved initial data

    NASA Astrophysics Data System (ADS)

    Lovelace, Geoffrey

    2009-06-01

    At early times in numerical evolutions of binary black holes, current simulations contain an initial burst of spurious gravitational radiation (also called 'junk radiation') which is not astrophysically realistic. The spurious radiation is a consequence of how the binary-black-hole initial data are constructed: the initial data are typically assumed to be conformally flat. In this paper, I adopt a curved conformal metric that is a superposition of two boosted, non-spinning black holes that are approximately 15 orbits from merger. I compare junk radiation of the superposed-boosted-Schwarzschild (SBS) initial data with the junk of corresponding conformally flat, maximally sliced (CFMS) initial data. The SBS junk is smaller in amplitude than the CFMS junk, with the junk's leading-order spectral modes typically being reduced by a factor of order 2 or more.

  8. Superintegrability of d-Dimensional Conformal Blocks.

    PubMed

    Isachenkov, Mikhail; Schomerus, Volker

    2016-08-12

    We observe that conformal blocks of scalar four-point functions in a d-dimensional conformal field theory can be mapped to eigenfunctions of a two-particle hyperbolic Calogero-Sutherland Hamiltonian. The latter describes two coupled Pöschl-Teller particles. Their interaction, whose strength depends smoothly on the dimension d, is known to be superintegrable. Our observation enables us to exploit the rich mathematical literature on Calogero-Sutherland models in deriving various results for conformal field theory. These include an explicit construction of conformal blocks in terms of Heckman-Opdam hypergeometric functions. We conclude with a short outlook, in particular, on the consequences of integrability for the theory of conformal blocks. PMID:27563949

  9. Conformational analysis of 2-substituted piperazines.

    PubMed

    Kallel, E Adam; Vangel, Colin; Elbaum, Daniel

    2016-07-01

    The unusual activity differences of carbon linked versus oxygen linked 2-substituted piperazines as α7 nicotinic acetylcholine receptor agonists led to a conformational study of several examples. The conformational preferences of which are absent from the literature. We report the first study and explanation of the conformational preference of 2-substiturted piperazines and show an example of how this preference controls binding in a pharmaceutically relevant case. In all cases the axial conformation for these 1-acyl and 1 aryl 2-substituted piperazines was found to be preferred. For the ether linked compounds, the axial conformation was found to be further stabilized by an intramolecular hydrogen bond. The axial orientation also places the basic and pyridyl nitrogens into a special orientation that closely mimics nicotine. Molecular modeling studies confirm that the R enantiomers of the compounds can bind to the α7 nicotinic acetylcholine receptor with the basic and pyridyl nitrogens colocalized with their counterparts in Epibatidine. PMID:27212066

  10. Vertex operator algebras and conformal field theory

    SciTech Connect

    Huang, Y.Z. )

    1992-04-20

    This paper discusses conformal field theory, an important physical theory, describing both two-dimensional critical phenomena in condensed matter physics and classical motions of strings in string theory. The study of conformal field theory will deepen the understanding of these theories and will help to understand string theory conceptually. Besides its importance in physics, the beautiful and rich mathematical structure of conformal field theory has interested many mathematicians. New relations between different branches of mathematics, such as representations of infinite-dimensional Lie algebras and Lie groups, Riemann surfaces and algebraic curves, the Monster sporadic group, modular functions and modular forms, elliptic genera and elliptic cohomology, Calabi-Yau manifolds, tensor categories, and knot theory, are revealed in the study of conformal field theory. It is therefore believed that the study of the mathematics involved in conformal field theory will ultimately lead to new mathematical structures which would be important to both mathematics and physics.

  11. Dolastatin 11 conformations, analogues and pharmacophore.

    PubMed

    Ali, Md Ahad; Bates, Robert B; Crane, Zackary D; Dicus, Christopher W; Gramme, Michelle R; Hamel, Ernest; Marcischak, Jacob; Martinez, David S; McClure, Kelly J; Nakkiew, Pichaya; Pettit, George R; Stessman, Chad C; Sufi, Bilal A; Yarick, Gayle V

    2005-07-01

    Twenty analogues of the natural antitumor agent dolastatin 11, including majusculamide C, were synthesized and tested for cytotoxicity against human cancer cells and stimulation of actin polymerization. Only analogues containing the 30-membered ring were active. Molecular modeling and NMR evidence showed the low-energy conformations. The amide bonds are all trans except for the one between the Tyr and Val units, which is cis. Since an analogue restricted to negative 2-3-4-5 angles stimulated actin polymerization but was inactive in cells, the binding conformation (most likely the lowest-energy conformation in water) has a negative 2-3-4-5 angle, whereas a conformation with a positive 2-3-4-5 angle (most likely the lowest energy conformation in chloroform) goes through cell walls. The highly active R alcohol from borohydride reduction of dolastatin 11 is a candidate for conversion to prodrugs. PMID:15878670

  12. 10. Exploring the Conformal Constraint Equations

    NASA Astrophysics Data System (ADS)

    Butscher, Adrian

    One method of studying the asymptotic structure of spacetime is to apply Penrose's conformal rescaling technique. In this setting, the rescaled Einstein equations for the metric and the conformal factor in the unphysical spacetime degenerate where the conformal factor vanishes, namely at the boundary representing null infinity. This problem can be avoided by means of a technique of H. Friedrich, which replaces the Einstein equations in the unphysical spacetime by an equivalent system of equations which is regular at the boundary. The initial value problem for these equations produces a system of constraint equations known as the conformal constraint equations. This work describes some of the properties of the conformal constraint equations and develops a perturbative method of generating solutions near Euclidean space under certain simplifying assumptions.

  13. Examining Adsorbed Polymer Conformations with Fluorescence Imaging

    NASA Astrophysics Data System (ADS)

    Parkes, Maria; Chennaoui, Mourad; Wong, Janet; Tribology Group, Dept. of Mechanical Engineering Team

    2011-03-01

    The conformation of adsorbed polymers can have significant impact on their properties such as dynamics and elasticity as well as their ability to take part in reactions with other molecules. Experimental research to determine adsorbed polymer conformation has relied mainly on atomic force microscopy (AFM) studies. During an AFM scan, the contact between the scanning probe and the polymer could affect the polymer conformation, particularly where parts of the polymer might have formed projected loops and tails. In this work, conformations of model polymers are examined with total internal reflection fluorescence microscopy (TIRFM). The advantage of TIRFM over AFM is that TIRFM is a non contact technique. Lambda DNA labelled along its length with fluorescent probes was adsorbed in a projected 2D -- 3D state. With TIRFM, the relationship between intensity and depth was used as a basis to determine how the conformation of the adsorbed polymers evolved with time using our custom algorithm.

  14. Protein biosynthesis with conformationally restricted amino acids

    SciTech Connect

    Mendel, D. Lawrence Berkeley Lab., CA ); Ellman, J.; Schultz, P.G. )

    1993-05-19

    The incorporation of conformationally constrained amino acids into peptides is a powerful approach for generating structurally defined peptides as conformational probes and bioactive agents. The ability to site-specifically introduce constrained amino acids into large polypeptide chains would provide a similar opportunity to probe the flexibility, conformation, folding and stability of proteins. To this end, we have examined the competence of the Escherichia coli protein biosynthetic machinery to incorporate a number of these unnatural amino acids into the 164 residue protein T4 lysozyme (T4L). Results clearly demonstrate that the protein biosynthetic machinery can accommodate a wide variety of conformationally constrained amino acids. The expansion of structural motifs that can be biosynthetically incorporated into proteins to include a large number of conformationally constrained amino acids significantly increases the power of mutagenesis methods as probes of protein structure and function and provides additional insights into the steric requirements of the translational machinery. 13 refs., 2 figs.

  15. Superintegrability of d -Dimensional Conformal Blocks

    NASA Astrophysics Data System (ADS)

    Isachenkov, Mikhail; Schomerus, Volker

    2016-08-01

    We observe that conformal blocks of scalar four-point functions in a d -dimensional conformal field theory can be mapped to eigenfunctions of a two-particle hyperbolic Calogero-Sutherland Hamiltonian. The latter describes two coupled Pöschl-Teller particles. Their interaction, whose strength depends smoothly on the dimension d , is known to be superintegrable. Our observation enables us to exploit the rich mathematical literature on Calogero-Sutherland models in deriving various results for conformal field theory. These include an explicit construction of conformal blocks in terms of Heckman-Opdam hypergeometric functions. We conclude with a short outlook, in particular, on the consequences of integrability for the theory of conformal blocks.

  16. Performance of Conformable Ablators in Aerothermal Environments

    NASA Technical Reports Server (NTRS)

    Thornton, J.; Fan, W.; Skokova, K.; Stackpoole, M.; Beck, R.; Chavez-Garcia, J.

    2012-01-01

    Conformable Phenolic Impregnated Carbon Ablator, a cousin of Phenolic Impregnated Carbon Ablator (PICA), was developed at NASA Ames Research Center as a lightweight thermal protection system under the Fundamental Aeronautics Program. PICA is made using a brittle carbon substrate, which has a very low strain to failure. Conformable PICA is made using a flexible carbon substrate, a felt in this case. The flexible felt significantly increases the strain to failure of the ablator. PICA is limited by its thermal mechanical properties. Future NASA missions will require heatshields that are more fracture resistant than PICA and, as a result, NASA Ames is working to improve PICAs performance by developing conformable PICA to meet these needs. Research efforts include tailoring the chemistry of conformable PICA with varying amounts of additives to enhance mechanical properties and testing them in aerothermal environments. This poster shows the performance of conformable PICA variants in arc jets tests. Some mechanical and thermal properties will also be presented.

  17. Measuring chromosome conformation with degenerate labels

    NASA Astrophysics Data System (ADS)

    Ross, Brian C.; Wiggins, Paul A.

    2012-07-01

    Although DNA conformation plays an integral role in all genetic processes from transcription to chromosome segregation, there is as yet no tractable method for capturing the in vivo conformation of a chromosome at high resolution. Labeling and fluorescently imaging thousands of loci along the chromosome would readily yield a conformation if each locus could be uniquely distinguished in the image, but this would unrealistically require thousands of distinguishable labels and a tedious experimental process. Here we present a computational method for extracting conformations when the total number of labels far exceeds the number of distinguishable labels. We evaluate our technique using simulated conformations with lengths ranging from 10 to 100 kilobases, and discuss the prospects for an experiment.

  18. Conforming Morse-Smale Complexes

    SciTech Connect

    Gyulassy, Attila; Gunther, David; Levine, Joshua A.; Tierny, Julien; Pascucci, Valerio

    2014-08-11

    Morse-Smale (MS) complexes have been gaining popularity as a tool for feature-driven data analysis and visualization. However, the quality of their geometric embedding and the sole dependence on the input scalar field data can limit their applicability when expressing application-dependent features. In this paper we introduce a new combinatorial technique to compute an MS complex that conforms to both an input scalar field and an additional, prior segmentation of the domain. The segmentation constrains the MS complex computation guaranteeing that boundaries in the segmentation are captured as separatrices of the MS complex. We demonstrate the utility and versatility of our approach with two applications. First, we use streamline integration to determine numerically computed basins/mountains and use the resulting segmentation as an input to our algorithm. This strategy enables the incorporation of prior flow path knowledge, effectively resulting in an MS complex that is as geometrically accurate as the employed numerical integration. Our second use case is motivated by the observation that often the data itself does not explicitly contain features known to be present by a domain expert. We introduce edit operations for MS complexes so that a user can directly modify their features while maintaining all the advantages of a robust topology-based representation.

  19. Conformal Higgs, or Techni-Dilaton -- Composite Higgs Near Conformality

    NASA Astrophysics Data System (ADS)

    Yamawaki, Koichi

    2011-01-01

    In contrast to the folklore that Technicolor (TC) is a "Higgsless theory", we shall discuss existence of a composite Higgs boson, Techni-Dilaton (TD), a pseudo-Nambu-Goldstone boson of the scale invariance in the Scale-invariant/Walking/Conformal TC (SWC TC) which generates a large anomalous dimension γm ≃ 1 in a wide region from the dynamical mass m = {O} ({TeV}) of the techni-fermion all the way up to the intrinsic scale ΛTC of the SWC TC (analogue of ΛQCD), where ΛTC is taken typically as the scale of the Extended TC scale ΛETC: ΛTC ≃ ΛETC 103 TeV (≫ m). All the techni-hadrons have mass on the same order {O}(m), which in SWC TC is extremely smaller than the intrinsic scale ΛTC ≃ ΛETC, in sharp contrast to QCD where both are of the same order. The mass of TD arises from the non-perturbative scale anomaly associated with the techni-fermion mass generation and is typically 500-600 GeV, even smaller than other techni-hadrons of the same order of {O}(m), in another contrast to QCD which is believed to have no scalar bar qq bound state lighter than other hadrons. We discuss the TD mass in various methods, Gauged NJL model via ladder Schwinger-Dyson (SD) equation, straightforward calculations in the ladder SD/ Bethe-Salpeter equation, and the holographic approach including techni-gluon condensate. The TD may be discovered in LHC.

  20. Conformational Flexibility in the Flap Domains of Ligand-Free HIV Protease

    SciTech Connect

    Heaslet, H.; Rosenfeld, R.; Giffin, M.; Lin, Y.-C.; Tam, K.; Torbett, B.E.; Elder, J.H.; Stout, C.D.

    2009-06-01

    The crystal structures of wild-type HIV protease (HIV PR) in the absence of substrate or inhibitor in two related crystal forms at 1.4 and 2.15 {angstrom} resolution are reported. In one crystal form HIV PR adopts an 'open' conformation with a 7.7 {angstrom} separation between the tips of the flaps in the homodimer. In the other crystal form the tips of the flaps are 'curled' towards the 80s loop, forming contacts across the local twofold axis. The 2.3 {angstrom} resolution crystal structure of a sixfold mutant of HIV PR in the absence of substrate or inhibitor is also reported. The mutant HIV PR, which evolved in response to treatment with the potent inhibitor TL-3, contains six point mutations relative to the wild-type enzyme (L24I, M46I, F53L, L63P, V77I, V82A). In this structure the flaps also adopt a 'curled' conformation, but are separated and not in contact. Comparison of the apo structures to those with TL-3 bound demonstrates the extent of conformational change induced by inhibitor binding, which includes reorganization of the packing between twofold-related flaps. Further comparison with six other apo HIV PR structures reveals that the 'open' and 'curled' conformations define two distinct families in HIV PR. These conformational states include hinge motion of residues at either end of the flaps, opening and closing the entire {beta}-loop, and translational motion of the flap normal to the dimer twofold axis and relative to the 80s loop. The alternate conformations also entail changes in the {beta}-turn at the tip of the flap. These observations provide insight into the plasticity of the flap domains, the nature of their motions and their critical role in binding substrates and inhibitors.

  1. Perceived Symbols of Authority and Their Influence on Conformity.

    ERIC Educational Resources Information Center

    Bushman, Brad J.

    Although there are many variables that influence conformity, Bickman (1974) found that the apparel of the person making a request had a significant influence on conformity. To evaluate other factorswhicn may influence conformity (gender, age, status of the conforming subject, and altruism in conforming), 150 adult pedestrians (45% female, 71%…

  2. The paradox of conformational constraint in the design of Cbl(TKB)-binding peptides

    PubMed Central

    Kumar, Eric A.; Chen, Qianyi; Kizhake, Smitha; Kolar, Carol; Kang, Myungshim; Chang, Chia-en A.; Borgstahl, Gloria E. O.; Natarajan, Amarnath

    2013-01-01

    Solving the crystal structure of Cbl(TKB) in complex with a pentapeptide, pYTPEP, revealed that the PEP region adopted a poly-L-proline type II (PPII) helix. An unnatural amino acid termed a proline-templated glutamic acid (ptE) that constrained both the backbone and sidechain to the bound conformation was synthesized and incorporated into the pYTPXP peptide. We estimated imposing structural constraints onto the backbone and sidechain of the peptide and preorganize it to the bound conformation in solution will yield nearly an order of magnitude improvement in activity. NMR studies confirmed that the ptE-containing peptide adopts the PPII conformation, however, competitive binding studies showed an order of magnitude loss of activity. Given the emphasis that is placed on imposing structural constraints, we provide an example to support the contrary. These results point to conformational flexibility at the interface, which have implications in the design of potent Cbl(TKB)-binding peptides. PMID:23572190

  3. Comparison of the solution and crystal conformations of (G + C)-rich fragments of DNA.

    PubMed Central

    Vorlícková, M; Subirana, J A; Chládková, J; Tejralová, I; Huynh-Dinh, T; Arnold, L; Kypr, J

    1996-01-01

    DNA fragments crystallize in an unpredictable manner, and relationships between their crystal and solution conformations still are not known. We have studied, using circular dichroism spectroscopy, solution conformations of (G + C)-rich DNA fragments, the crystal structures of which were solved in the laboratory of one of the present authors. In aqueous trifluorethanol (TFE) solutions, all of the examined oligonucleotides adopted the same type of double helix as in the crystal. Specifically, the dodecamer d(CCCCCGCGGGGG) crystalized as A-DNA and isomerized into A-DNA at high TFE concentrations. On the other hand, the hexamer d(CCGCGG) crystallized in Z-form containing tilted base pairs, and high TFE concentrations cooperatively transformed it into the same Z-form as adopted by the RNA hexamer r(CGCGCG), although d(CCGCGG) could isomerize into Z-DNA in the NaCl + NiCl2) aqueous solution. The fragments crystallizing as B-DNA remained B-DNA, regardless of the solution conditions, unless they denatured or aggregated. Effects on the oligonucleotide conformation of 2-methyl-2,4-pentanediol and other crystallization agents were also studied. 2-Methyl-2,4-pentanediol induced the same conformational transitions as TFE but, in addition, caused an oligonucleotide condensation that was also promoted by the other crystallization agents. The present results indicate that the crystal double helices of DNA are stable in aqueous TFE rather than aqueous solution. PMID:8874026

  4. Matrix Isolation FTIR and AB Initio Studies on the Conformations of Dimethyl and Diethyl Carbonate and Their Complexes with Water

    NASA Astrophysics Data System (ADS)

    Kar, Bishnu Prasad; Ramanathan, N.; Sundararajan, K.; Viswanathan, K. S.

    2011-06-01

    Dimethyl carbonate (DMC) and diethyl carbonate (DEC) have been studied for their conformations using matrix isolation infrared spectroscopy and ab initio computations. In addition to the above studies, the complexes of the two compounds with water have also been studied. The experiments were corroborated with ab initio calculations at the B3LYP/6-31++G** level. The organic carbonates were trapped in argon and nitrogen matrixes using an effusive source maintained at two different temperatures; i.e. room temperature and 170°C. In addition the matrix was also deposited using a supersonic jet source. These experiments were performed to alter the relative population of the various conformations, to aid us in the assignments of the vibrational features. The conformation of DMC corresponding to the global minimum of DMC was found to be a cis-cis conformer where the two methyl groups are found to be at cis position with respect to the carbonyl oxygen. The next higher energy conformer corresponded to a cis-trans structure with a near trans-near trans structure being the highest energy conformer. In our experimental matrix isolation spectra of DMC, we were able to assign features due to the cis-cis and cis-trans conformers. The features of the higher energy cis-trans conformer was confirmed with our experiments using the elevated temperature effusive source and the supersonic source. DEC displays a richer conformational landscape due to the presence of a longer carbon chain. The computational and experimental indicate that the ground state conformer for this compound is one in which carbon attached to oxygen adopts a cis configuration with respect to the carbonyl oxygen, while the terminal carbon adopts an anti conformation. A detailed study of the conformational picture of DEC will be presented. In addition to the above conformational studies, 1:1 hydrogen bonded complexes of DMC and DEC with water were also observed in the matrix, which was corroborated by our

  5. Initiation factor 2 stabilizes the ribosome in a semirotated conformation.

    PubMed

    Ling, Clarence; Ermolenko, Dmitri N

    2015-12-29

    Intersubunit rotation and movement of the L1 stalk, a mobile domain of the large ribosomal subunit, have been shown to accompany the elongation cycle of translation. The initiation phase of protein synthesis is crucial for translational control of gene expression; however, in contrast to elongation, little is known about the conformational rearrangements of the ribosome during initiation. Bacterial initiation factors (IFs) 1, 2, and 3 mediate the binding of initiator tRNA and mRNA to the small ribosomal subunit to form the initiation complex, which subsequently associates with the large subunit by a poorly understood mechanism. Here, we use single-molecule FRET to monitor intersubunit rotation and the inward/outward movement of the L1 stalk of the large ribosomal subunit during the subunit-joining step of translation initiation. We show that, on subunit association, the ribosome adopts a distinct conformation in which the ribosomal subunits are in a semirotated orientation and the L1 stalk is positioned in a half-closed state. The formation of the semirotated intermediate requires the presence of an aminoacylated initiator, fMet-tRNA(fMet), and IF2 in the GTP-bound state. GTP hydrolysis by IF2 induces opening of the L1 stalk and the transition to the nonrotated conformation of the ribosome. Our results suggest that positioning subunits in a semirotated orientation facilitates subunit association and support a model in which L1 stalk movement is coupled to intersubunit rotation and/or IF2 binding. PMID:26668356

  6. Synthesis, conformational parameters and packing considerations of methyl bispyridyl ketones

    NASA Astrophysics Data System (ADS)

    Weck, Christian; Katzsch, Felix; Gruber, Tobias

    2015-10-01

    The crystal structures of two bispyridyl ketones featuring either two methyl residues or one methyl and one bromomethyl residue, respectively, are presented. In order to elucidate the influence of the substituents, a comprehensive comparison with the non-methylated mother compound has been performed. A special focus lies thereby on the relative position of the heteroatoms and their free electron pairs. The two methyl groups at the bispyridyl ketone result in two molecules in the asymmetric unit adopting rather different conformations. Due to the fast crystallization conditions and a melting point differing from the literature, a polymorph close to a local minimum in the energy hypersurface seems possible. After introducing a bromine atom to one of the two methyl groups, the molecular conformation is very similar to the unsubstituted molecule. The packing of both title compounds is dominated by weak contacts of the C-H⋯π and C-H⋯Y type (Y = O, N) and C-H⋯Br- and Br⋯π-contacts for the brominated molecule.

  7. Conformational Variety of Polyanionic Peptides At Low Salt Concentrations

    NASA Astrophysics Data System (ADS)

    Bertrand, Marylène; Brack, André

    1997-12-01

    Cordially dedicated to Dr. Leslie Orgel on the occasion of his 70th birthday. Sequential oligo- and polypeptides based on glutamic acid and leucine residues have been synthesized. In pure water, they exhibit a random coil conformation. Addition of very small amounts of divalent metallic cations induces the formation of ordered structure in the peptides which remain in solution. Higher salt concentrations precipitate the peptides. Polypeptides with alternating glutamic acid and leucine residues undergo a coil to β-sheet transition in the presence of Ca^2+, Ba^2+, Mn^2+, Co^2+, Zn^2+ and Hg^2+. Addition of Cu^2+ or Fe^3+ induces the formation of an α-helix. Solid amorphous CdS generates water soluble β-sheets, as well. Sequential poly(Leu-Glu-Glu-Leu) adopts an α-helix in the presence of divalent cations. The sequence-dependent conformational diversity was extended to poly(Asp-Leu) and poly(Leu-Asp-Asp-Leu).

  8. Conformational Dynamics in DNA Replication Selectivity

    NASA Astrophysics Data System (ADS)

    Brieba, Luis G.

    2007-11-01

    Replicative DNA polymerases are remarkable molecular machines that carry out DNA synthesis accordingly to the Watson and Crick rules (Guanine pairs with Cytosine and Adenine with Thymidine) with high specificity or fidelity. The biochemical mechanism that dictates polymerase fidelity has its fundaments in the tight active site of replicative polymerases and the shape and size of the Watson-Crick base pairs. Pre-steady state kinetic analysis have shown that during polymerase nucleotide addition, the chemical reaction is not the rate limiting step and it was postulated that DNA polymerases suffer a conformational change from an "open" to a "closed" conformation before chemistry which is also the step responsible for their high fidelity. Crystal structures of replicative DNA polymerases demonstrated that the fingers subdomain suffers a large conformational change during catalysis and that this conformational transition aligns the polymerase active site in a proper conformation for catalysis. Recent studies using single molecule techniques and Fluorescence Resonance Energy Transfer analysis also shown that at least in the case of T7 DNA polymerase, the closure of the fingers subdomain is in part the rate limiting step associated with the high fidelity of DNA polymerases, although the overall fidelity of the reaction maybe involves an assemble of chemical steps and several conformational changes. Our current knowledge indicates that the mechanisms of enzyme specificity in DNA replication involve several energy landscapes that maybe correlated with conformational changes and active site assemblies.

  9. Conformation of oligodeoxynucleotides associated with anionic liposomes

    PubMed Central

    Patil, Siddhesh D.; Rhodes, David G.

    2000-01-01

    There has been significant progress in the development of antisense therapeutics for a wide range of medicinal applications. Further improvement will require better understanding of cellular internalization, intracellular distribution mechanisms and interactions of oligodeoxynucleotides with cellular organelles. In many of these processes interactions of oligodeoxynucleotides with lipid assemblies may have a significant influence on their function. Divalent cations have been shown to assist cellular internalization of certain oligodeoxynucleotides and to affect their conformation. In this work we have investigated conformational changes of phosphorothioate oligodeoxynucleotides upon divalent cation-mediated interaction with 1,2-dipalmitoyl-sn-glycero-3-phosphatidylglycerol (DPPG) liposomes. For the sequences investigated here the native conformation underwent significant change in the presence of anionic DPPG liposomes only when divalent cations were present. This change is sequence-specific, ion-selective and distinct from previously reported changes in oligodeoxynucleotide structure due to divalent cations alone. The conformation of one oligodeoxynucleotide in the presence of calcium and DPPG yields circular dichroism spectra which suggest C-DNA but which also have characteristics unlike any previously reported spectra of liposome-associated DNA structure. The data suggest the possibility of a unique conformation of liposome-associated ODNs and reflect a surprisingly strong tendency of single-stranded DNA to retain a characteristic conformation even when adsorbed to a surface. This conformation may be related to cellular uptake, transport of oligodeoxynucleotides in cells and/or function. PMID:11058108

  10. The Principle of Maximum Conformality

    SciTech Connect

    Brodsky, Stanley J; Giustino, Di; /SLAC

    2011-04-05

    A key problem in making precise perturbative QCD predictions is the uncertainty in determining the renormalization scale of the running coupling {alpha}{sub s}({mu}{sup 2}). It is common practice to guess a physical scale {mu} = Q which is of order of a typical momentum transfer Q in the process, and then vary the scale over a range Q/2 and 2Q. This procedure is clearly problematic since the resulting fixed-order pQCD prediction will depend on the renormalization scheme, and it can even predict negative QCD cross sections at next-to-leading-order. Other heuristic methods to set the renormalization scale, such as the 'principle of minimal sensitivity', give unphysical results for jet physics, sum physics into the running coupling not associated with renormalization, and violate the transitivity property of the renormalization group. Such scale-setting methods also give incorrect results when applied to Abelian QED. Note that the factorization scale in QCD is introduced to match nonperturbative and perturbative aspects of the parton distributions in hadrons; it is present even in conformal theory and thus is a completely separate issue from renormalization scale setting. The PMC provides a consistent method for determining the renormalization scale in pQCD. The PMC scale-fixed prediction is independent of the choice of renormalization scheme, a key requirement of renormalization group invariance. The results avoid renormalon resummation and agree with QED scale-setting in the Abelian limit. The PMC global scale can be derived efficiently at NLO from basic properties of the PQCD cross section. The elimination of the renormalization scheme ambiguity using the PMC will not only increases the precision of QCD tests, but it will also increase the sensitivity of colliders to new physics beyond the Standard Model.

  11. Anticholinergic substances: A single consistent conformation

    PubMed Central

    Pauling, Peter; Datta, Narayandas

    1980-01-01

    An interactive computer-graphics analysis of 24 antagonists of acetylcholine at peripheral autonomic post-ganglionic (muscarinic) nervous junctions and at similar junctions in the central nervous system, the crystal structures of which are known, has led to the determination of a single, consistent, energetically favorable conformation for all 24 substances, although their observed crystal structure conformations vary widely. The absolute configuration and the single, consistent (ideal) conformation of the chemical groups required for maximum anticholinergic activity are described quantitatively. Images PMID:16592775

  12. Conformations of polyaniline in polymer blends

    NASA Astrophysics Data System (ADS)

    Laska, Jadwiga

    2004-09-01

    Conformational studies of polyaniline (PANi) in its doped, i.e. conducting form, have been performed. The main goal of this study was to determine how the conformations depend on a dopant, solvent and a polymer matrix in polyaniline blends with classic polymers such as poly(methyl methacrylate), polystyrene, cellulose derivatives, polyamides, etc. The obtained results shown that even slight changes in polymer conformations can be easily checked by means of UV-vis-NIR or NIR only spectroscopy. On the basis of the described results, prediction of macroscopic properties of PANi samples, for example, conductivity, at the stage of preparation is possible.

  13. Conformity and Dissonance in Generalized Voter Models

    NASA Astrophysics Data System (ADS)

    Page, Scott E.; Sander, Leonard M.; Schneider-Mizell, Casey M.

    2007-09-01

    We generalize the voter model to include social forces that produce conformity among voters and avoidance of cognitive dissonance of opinions within a voter. The time for both conformity and consistency (which we call the exit time) is, in general, much longer than for either process alone. We show that our generalized model can be applied quite widely: it is a form of Wright's island model of population genetics, and is related to problems in the physical sciences. We give scaling arguments, numerical simulations, and analytic estimates for the exit time for a range of relative strengths in the tendency to conform and to avoid dissonance.

  14. Conformable Fractional Nikiforov—Uvarov Method

    NASA Astrophysics Data System (ADS)

    Karayer, H.; Demirhan, D.; Büyükkılıç, F.

    2016-07-01

    We introduce conformable fractional Nikiforov—Uvarov (NU) method by means of conformable fractional derivative which is the most natural definition in non-integer calculus. Since, NU method gives exact eigenstate solutions of Schrödinger equation (SE) for certain potentials in quantum mechanics, this method is carried into the domain of fractional calculus to obtain the solutions of fractional SE. In order to demonstrate the applicability of the conformable fractional NU method, we solve fractional SE for harmonic oscillator potential, Woods—Saxon potential, and Hulthen potential.

  15. Interferometric tomography metrology of conformal optics

    NASA Astrophysics Data System (ADS)

    Gutin, Mikhail; Gutin, Olga; Wang, Xu-Ming; Ehlinger, Dennis

    2013-06-01

    Conformal windows and domes improve aerodynamic quality of missiles and aircraft but introduce significant optical aberrations. These aberrations can be compensated, provided both window and corrective optics are fabricated to high tolerances. Highly accurate measurement of conformal optics is required for success of the fabrication process. This paper describes the development of the Interferometric Tomography - a new tool for metrology of conformal aspheric optics, including optics with very high aberrations. The metrology system is designed to measure wavefront aberrations as well as the optical figure of both surfaces.

  16. How Many Conformations Can a Protein Remember?

    NASA Astrophysics Data System (ADS)

    Fink, Thomas M.; Ball, Robin C.

    2001-11-01

    We show that a protein can be trained to recognize multiple conformations, analogous to an associative memory, and provide capacity calculations based on energy fluctuations and information theory. Unlike the linear capacity of a Hopfield network, the number of conformations which can be remembered by a protein sequence depends on the size of the amino acid alphabet as lnA, independent of protein length. This admits the possibility of certain proteins, such as prions, evolving to fold to independent stable conformations, as well as novel possibilities for protein and heteropolymer design.

  17. Structure, Intent and Conformance Monitoring in ATC

    NASA Technical Reports Server (NTRS)

    Reynolds, Tom G.; Histon, Jonathan M.; Davison, Hayley J.; Hansman, R. John

    2004-01-01

    Infield studies of current Air Traffic Control operations it is found that controllers rely on underlying airspace structure to reduce the complexity of the planning and conformance monitoring tasks. The structure appears to influence the controller's working mental model through abstractions that reduce the apparent cognitive complexity. These structure-based abstractions are useful for the controller's key tasks of planning, implementing, monitoring, and evaluating tactical situations. In addition, the structure-based abstractions appear to be important in the maintenance of Situation Awareness. The process of conformance monitoring is analyzed in more detail and an approach to conformance monitoring which utilizes both the structure-based abstractions and intent is presented.

  18. Scalar scattering via conformal higher spin exchange

    NASA Astrophysics Data System (ADS)

    Joung, Euihun; Nakach, Simon; Tseytlin, Arkady A.

    2016-02-01

    Theories containing infinite number of higher spin fields require a particular definition of summation over spins consistent with their underlying symmetries. We consider a model of massless scalars interacting (via bilinear conserved currents) with conformal higher spin fields in flat space. We compute the tree-level four-scalar scattering amplitude using a natural prescription for summation over an infinite set of conformal higher spin exchanges and find that it vanishes. Independently, we show that the vanishing of the scalar scattering amplitude is, in fact, implied by the global conformal higher spin symmetry of this model. We also discuss one-loop corrections to the four-scalar scattering amplitude.

  19. Adopted children from the former Soviet Union

    PubMed Central

    Koren, Gideon

    2013-01-01

    Abstract Question One of the families in my practice is considering adoption of a 2-year-old child from the former Soviet Union. The family has been reassured by the agency that a doctor will examine the child to rule out developmental delays. However, my understanding from your previous articles is that one cannot rule out fetal alcohol spectrum disorder (FASD) at that age. Are these children at increased risk of developing FASD? Answer You are correct: FASD cannot be ruled out at 2 years of age. The risk of FASD, neglect, and abuse among children in orphanages in the former Soviet Union is high. While adoption of children with known developmental delays should be encouraged and supported, most families seek to adopt with the assumption that these children will be healthy. PMID:24130279

  20. Breaking the addiction to technology adoption.

    PubMed

    Bryan, Stirling; Mitton, Craig; Donaldson, Cam

    2014-04-01

    A major driver of cost growth in health care is the rapid increase in the utilisation of existing technology and not simply the adoption of new technology. Health economists and their health technology assessment colleagues have become obsessed by technology adoption questions and have largely ignored 'technology management' questions. Technology management would include the life-cycle assessment of technologies in use, to assess their real-world performance; and monitoring of technology indication creep. A rebalancing of focus might serve to encourage a more self-critical and learning culture amongst those involved in technology evaluation analysis. Further, health economists and health technology assessment analysts could make a more significant contribution to system efficiency through rebalancing their efforts away from technology adoption questions towards technology management issues. PMID:24590701

  1. (1′S,12′R,13′S,17′S)-15′,15′-Dimethyl-1,2-dihydro-11′,14′,16′,18′-tetra­oxa-7′-aza­spiro­[indole-3,8′-penta­cyclo­[10.6.0.02,9.03,7.013,17]octa­deca­ne]-2,10′-dione

    PubMed Central

    Sabari, V.; Ponnusamy, R.; Prasanna, R.; Raghunathan, R.; Aravindhan, S.

    2013-01-01

    In the title compound, C22H24N2O6, the indole ring has a twist conformation and the tetra­hydro-2H-pyran-2-one ring a half-chair conformation. One of the pyrrolidine rings adopts an envelope conformation on the N atom, while the other has a twist conformation; the ‘butterfly’ angle between their mean planes is 62.98 (11)°. The dioxolane ring adopts a twist conformation and the tetra­hydro­furan ring has an envelope conformation on the C atom in the fused tetra­hydro-2H-pyran-2-one ring adjacent to the O atom of the tetra­hydro­furan ring. The ‘butterfly’ angle between the mean planes of these two five-membered rings is 69.14 (10)°. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds, forming chains along the a axis. PMID:23634025

  2. Correlates of household seismic hazard adjustment adoption.

    PubMed

    Lindell, M K; Whitney, D J

    2000-02-01

    This study examined the relationships of self-reported adoption of 12 seismic hazard adjustments (pre-impact actions to reduce danger to persons and property) with respondents' demographic characteristics, perceived risk, perceived hazard knowledge, perceived protection responsibility, and perceived attributes of the hazard adjustments. Consistent with theoretical predictions, perceived attributes of the hazard adjustments differentiated among the adjustments and had stronger correlations with adoption than any of the other predictors. These results identify the adjustments and attributes that emergency managers should address to have the greatest impact on improving household adjustment to earthquake hazard. PMID:10795335

  3. On Adopting Educational Materials: A Cautionary Tale

    NASA Astrophysics Data System (ADS)

    Stewart, S.; Brown, D.; Dotger, S.

    2014-07-01

    The astronomy education community has made many educational materials publically available through various outlets. Unfortunately, adoption of educational materials does not guarantee instructional change. The materials—being nothing more than words on paper—are static, inert representations of abstract concepts that come to life only through interpretation and use by instructors and students. Research has previously demonstrated how instructors adopt, interpret, change, modify, and use materials in ways unanticipated by their developers (Brown 2009). This study investigates how a professor and teaching assistants used Engaging in Astronomical Inquiry (Slater, Slater, & Lyons 2010) during a laboratory section of an introductory astronomy course for nonscience majors.

  4. Adoptive Immunotherapy for Cancer or Viruses

    PubMed Central

    Maus, Marcela V.; Fraietta, Joseph A.; Levine, Bruce L.; Kalos, Michael; Zhao, Yangbing; June, Carl H.

    2015-01-01

    Adoptive immunotherapy, or the infusion of lymphocytes, is a promising approach for the treatment of cancer and certain chronic viral infections. The application of the principles of synthetic biology to enhance T cell function has resulted in substantial increases in clinical efficacy. The primary challenge to the field is to identify tumor-specific targets to avoid off-tissue, on-target toxicity. Given recent advances in efficacy in numerous pilot trials, the next steps in clinical development will require multicenter trials in order to establish adoptive immunotherapy as a mainstream technology. PMID:24423116

  5. Controlling the Conformational Changes in Donor–Acceptor [4]-Dendralenes through Intramolecular Charge-Transfer Processes

    PubMed Central

    Kanibolotsky, Alexander L; Forgie, John C; McEntee, Greg J; Talpur, M Munsif A; Skabara, Peter J; Westgate, Thomas DJ; McDouall, Joseph JW; Auinger, Michael; Coles, Simon J; Hursthouse, Michael B

    2009-01-01

    The synthesis of two [4]-dendralene compounds incorporating thiophene-(p-nitrophenyl) donor–acceptor units is presented. The dendralenes adopt two different conformers in solution and solid state and the transformation between the structures can be controlled by light and heat. The electron-donating components of the dendralenes are represented by bromothienyl (in 13) and ethylenedioxythiophene(EDOT)-thienyl (in 15) end-groups. The most facile transformation involves the isomerisation of donor–acceptor conjugated systems (a conformers) into structures in which only the thiophenes are conjugated (b conformers), and this process is driven by ambient light. The structures of the two conformers of compound 13 are confirmed by single-crystal X-ray diffraction studies and the structural changes in both compounds have been monitored by 1H NMR spectroscopy and absorption studies. The transformations were found to be first-order processes with rate constants of k = 0.0027 s−1 and k = 0.00022 s−1 for 13 and 15, respectively. Density functional theory calculations at the B3LYP/6-31G∗ level give credence to the proposed mechanism for the a→b conversion, which involves photoinduced intramolecular charge transfer (ICT) as the key step. The EDOT derivative (15) can be polymerised by electrochemical oxidation and a combination of cyclic voltammetry and UV/Vis spectroelectrochemical experiments indicate that the a conformer can be trapped and stabilised in the solid state. PMID:19760710

  6. Unusual folded conformation of nicotinamide adenine dinucleotide bound to flavin reductase P.

    PubMed Central

    Tanner, J. J.; Tu, S. C.; Barbour, L. J.; Barnes, C. L.; Krause, K. L.

    1999-01-01

    The 2.1 A resolution crystal structure of flavin reductase P with the inhibitor nicotinamide adenine dinucleotide (NAD) bound in the active site has been determined. NAD adopts a novel, folded conformation in which the nicotinamide and adenine rings stack in parallel with an inter-ring distance of 3.6 A. The pyrophosphate binds next to the flavin cofactor isoalloxazine, while the stacked nicotinamide/adenine moiety faces away from the flavin. The observed NAD conformation is quite different from the extended conformations observed in other enzyme/NAD(P) structures; however, it resembles the conformation proposed for NAD in solution. The flavin reductase P/NAD structure provides new information about the conformational diversity of NAD, which is important for understanding catalysis. This structure offers the first crystallographic evidence of a folded NAD with ring stacking, and it is the first enzyme structure containing an FMN cofactor interacting with NAD(P). Analysis of the structure suggests a possible dynamic mechanism underlying NADPH substrate specificity and product release that involves unfolding and folding of NADP(H). PMID:10493573

  7. Beyond halo mass: galactic conformity as a smoking gun of central galaxy assembly bias

    NASA Astrophysics Data System (ADS)

    Hearin, Andrew P.; Watson, Douglas F.; van den Bosch, Frank C.

    2015-09-01

    Quenched central galaxies tend to reside in a preferentially quenched large-scale environment, a phenomenon that has been dubbed galactic conformity. Remarkably, this tendency persists out to scales far larger than the virial radius of the halo hosting the central. Therefore, conformity manifestly violates the widely adopted assumption that the dark matter halo mass Mvir exclusively governs galaxy occupation statistics. This paper is the first in a series studying the implications of the observed conformity signal for the galaxy-dark matter connection. We show that recent measurements of conformity on scales r ˜ 1-5 Mpc imply that central galaxy quenching statistics cannot be correctly predicted with the knowledge of Mvir alone. We also demonstrate that ejected (or `backsplash') satellites cannot give rise to the signal. We then invoke the age matching model, which is predicated on the co-evolution of galaxies and haloes. We find that this model produces a strong signal, and that central galaxies are solely responsible. We conclude that large-scale `two-halo' conformity represents a smoking gun of central galaxy assembly bias, and indicates that contemporary models of satellite quenching have systematically overestimated the influence of post-infall processes.

  8. The Role of CH···O Coulombic Interactions in Determining Rotameric Conformations of Phenyl Substituted 1,3-Dioxanes and Tetrahydropyrans.

    PubMed

    Wiberg, Kenneth B; Lambert, Kyle M; Bailey, William F

    2015-08-21

    The rotameric conformations of the phenyl ring in both the axial and the equatorial conformers of phenyl substituted 1,3-dioxanes and tetrahydropyrans are compared with those of the corresponding phenylcyclohexanes at the MP2/6-311+G* level. The compounds with an axial phenyl commonly adopt a conformation in which the plane of the aromatic ring is perpendicular to the benzylic C-H bond. However, axial 5-phenyl-1,3-dioxane adopts a "parallel" conformation that allows an ortho hydrogen to be proximate to the two ring oxygens, leading to attractive CH···O interactions. Stabilizing Coulombic interactions of this sort are found with many of the oxygen-containing six-membered rings that were investigated. PMID:26182246

  9. Crystal structure of (±)-(1SR,5SR,6SR,7SR,10SR,11SR,13SR)-13-benz­yloxy-7-meth­oxy­meth­oxy-11,15,18,18-tetra­methyl-3-oxo-2,4-dioxa­tetra­cyclo­[12.3.1.01,5.06,11]octa­deca-14,16-dien-10-yl benzoate

    PubMed Central

    Oishi, Takeshi; Fukaya, Keisuke; Yamaguchi, Yu; Sugai, Tomoya; Watanabe, Ami; Sato, Takaaki; Chida, Noritaka

    2015-01-01

    In the title compound, C36H42O8, the dioxolane ring adopts a twist conformation; the two adjacent C atoms deviate alternately from the mean plane of other atoms by −0.287 (5) and 0.174 (5) Å. The cyclo­hexane, cyclo­hexa­diene and central cyclo­octane rings show chair, half-chair and boat–chair forms, respectively. As a result of the strained ring system, the tetra­subsituted olefin in the cyclo­hexa­diene is skewed from an ideal planar structure. In the crystal, C—H⋯O hydrogen bonds connect the mol­ecules into a sheet parallel to (100). The sheets are further linked by other weak C—H⋯O and C—H⋯π inter­actions, forming a three-dimensional network. PMID:25995863

  10. 5,5'-Di-tert-butyl-2,2'-dihydroxy-3,3'-methylenedibenzaldehyde and 6,6'-di-tert-butyl-8,8'-methylenebis(spiro[4H-1,3-benzodioxin-2,1'-cyclohexane]).

    PubMed

    Masci, Bernardo; Mortera, Stefano Levi; Seralessandri, Luca; Thuéry, Pierre

    2004-02-01

    Two related compounds containing p-tert-butyl-o-methylene-linked phenol or phenol-derived subunits are described, namely 5,5'-di-tert-butyl-2,2'-dihydroxy-3,3'-methylenedibenzaldehyde, C(23)H(28)O(4), (I), and 6,6'-di-tert-butyl-8,8'-methylenebis(spiro[4H-1,3-benzodioxin-2,1'-cyclohexane]), C(35)H(48)O(4), (II). Both compounds adopt a 'butterfly' shape, with the two phenol or phenol-derived O atoms in distal positions. Phenol and aldehyde groups in (I) are involved in intramolecular hydrogen bonds and the two dioxin rings in (II) are in distorted half-chair conformations. PMID:14767128

  11. N-(2,3-Dihydro-1,4-benzodioxin-6-yl)-4-fluoro­benzene­sulfonamide

    PubMed Central

    Mughal, Shumaila Younas; Khan, Islam Ullah; Harrison, William T. A.; Khan, Muneeb Hayat; Arshad, Muhammad Nadeem

    2012-01-01

    In the title compound, C14H12FNO4S, the dihedral angle between the aromatic rings is 50.26 (9)° and the C—S—N—C bond adopts a gauche conformation [torsion angle = −68.12 (15)°]. The dihydro­dioxine ring is disordered over two orientations, which both approximate to half-chairs, in a 0.880 (7):0.120 (7) ratio. In the crystal, N—H⋯O hydrogen bonds link the mol­ecules into C(4) chains propagating in [100]. Weak C—H⋯O and C—H⋯F inter­actions consolidate the packing. PMID:22904881

  12. Ethyl 4-(2,4-dichloro­phen­yl)-6-(6-meth­oxy-2-naphth­yl)-2-oxocyclo­hex-3-ene-1-carboxyl­ate

    PubMed Central

    Harrison, William T. A.; Mayekar, A. N.; Yathirajan, H. S.; Narayana, B.; Sarojini, B. K.

    2010-01-01

    In the title compound, C26H22Cl2O4, the cyclo­hexenone ring adopts an approximate half-chair conformation, with two C atoms displaced by −0.485 (6) and 0.218 (6) Å from the plane of the other four ring atoms. The dihedral angles between its four almost coplanar [maximum deviation = 0.006 (2) Å] atoms and the benzene and naphthalene ring systems are 59.26 (13) and 79.94 (9)°, respectively. The dihedral angle between the aromatic rings systems is 77.14 (7)°. A short intra­molecular C—H⋯Cl contact generates an S(6) ring. In the crystal, mol­ecules are linked by C—H⋯O and C—H⋯Cl inter­actions to generate a three-dimensional network. PMID:21587479

  13. Methyl 2-methyl-4-(oxiran-2-ylmeth-oxy)-2H-1,2-benzothia-zine-3-carboxyl-ate 1,1-dioxide.

    PubMed

    Ahmad, Matloob; Siddiqui, Hamid Latif; Zia-Ur-Rehman, Muhammad; Elsegood, Mark R J; Weaver, George W

    2010-01-01

    In the title compound, C(14)H(15)NO(6)S, the thia-zine ring adopts a distorted half-chair conformation. The structure displays several cooperative weak inter-molecular C-H⋯O hydrogen-bonding inter-actions, giving rise to a two-dimensional sheet packing motif. The CH(2) group in the meth-oxy linker to the oxirane ring, and the CH group in that ring, exhibit twofold positional disorder. The three-membered oxirane ring is twisted approximately perpendicular with respect to thia-zine ring (dihedral angle = 60/86° for the major/minor disorder components). 1,2-Benzothia-zines of this kind have a wide range of biological activities and are mainly used as medicines in the treatment of inflammation and rheumatoid arthritis. PMID:21579762

  14. N-(2,3-Dimethyl-phen-yl)-4-hydr-oxy-2-methyl-2H-1,2-benzothia-zine-3-carboxamide 1,1-dioxide.

    PubMed

    Siddiqui, Waseeq Ahmad; Bukahari, Iftikhar Hussain; Zia-Ur-Rehman, Muhammad; Khan, Islam Ullah; Tizzard, Graham John

    2009-01-01

    In the crystal structure of the title compound, C(18)H(18)N(2)O(4)S, the thia-zine ring adopts a distorted half-chair conformation. 1,2-Benzothia-zines of this kind have a wide range of biological activities and are mainly used as medicines in the treatment of inflammation and rheumatoid arthritis. The enolic H atom is involved in an intra-molecular O-H⋯O hydrogen bond, forming a six-membered ring. The mol-ecules arrange themselves into centrosymmetric dimers by means of inter-molecular N-H⋯O hydrogen bonds. A weak inter-molcular C-H⋯O inter-action is also present. PMID:21582293

  15. Crystal structure of 3-(4-meth-oxy-phen-yl)-2,3-di-hydro-1H-naphtho-[2,1-b]pyran-1-one.

    PubMed

    Vasanthi, R; Reuben Jonathan, D; Elizhlarasi, K S; Revathi, B K; Usha, G

    2015-05-01

    In the title compound, C20H16O3, the hydro-pyran ring adopts a distorted half-chair conformation with the methine C atom and the ring O atom displaced by -0.554 (2) and 0.158 (1) Å, respectively, from the plane of the other four atoms (r.m.s. deviation = 0.020 Å). Its mean plane (all atoms) is inclined to the naphthalene ring system at a dihedral angle of 11.67 (1)°. The dihedral angle between the napthalene ring system and the phenyl ring is 71.84 (1)°. In the crystal, no diectional inter-actions beyond van der Waals contacts could be identified. PMID:25995933

  16. 4-Imino-2,7-dimethyl-5,6,7,8-tetra-hydro-4H-1-benzothieno[2,3-d]pyrimidin-3-amine.

    PubMed

    Kalashetti, Mallikarjun B; Fathima, Nikhath; Khan, Ashraf Y; Begum, Noor Shahina; Khazi, I M

    2012-08-01

    In the title compound, C(12)H(16)N(4)S, the fused benzothio-phene and the pyrimidine rings are coplanar [dihedral angle = 1.61 (6)°]. Three C atoms of the cyclohexene ring (at positions 3, 6 and 7) are disordered over two sites with an occupancy ratio of 0.702 (8):0.298 (8). The cyclo-hexene ring in both the major and minor components adopts a half-chair conformation. The crystal structure is stabilized by N-H⋯N and C-H⋯N inter-actions, resulting in the formation of inversion dimers with R(2) (2)(10) and R(2) (2)(12) graph-set motifs. PMID:22904911

  17. The Influence of Lipid Bilayer Physicochemical Properties on Gramicidin A Conformer Preferences.

    PubMed

    Patrick, John W; Gamez, Roberto C; Russell, David H

    2016-04-26

    The conformational preferences adopted by gramicidin A (GA) dimers inserted into phospholipid bilayers are reported as a function of the bilayer cholesterol content, temperature, and incubation time. Through use of vesicle capture-freeze drying methodology, GA dimers were captured in lipid bilayers and the conformational preferences of the complex were analyzed using ion mobility-mass spectrometry. Perturbations that affect the physicochemical interactions in the lipid bilayer such as cholesterol incorporation, temperature, and incubation time directly alter the conformer preferences of the complex. Regardless of bilayer cholesterol concentration, the antiparallel double helix (ADH) conformation was observed to be most abundant for GA dimers in bilayers composed of lipids with 12 to 22 carbon acyl chains. Incorporation of cholesterol into lipid bilayers yields increased bilayer thickness and rigidity, and an increased abundance of parallel double helix (PDH) and single-stranded head-to-head (SSHH) dimers were observed. Bilayers prepared using 1,2-dilauroyl-sn-glycero-3-phosphocholine, a lipid with 12 carbon acyl chains, yielded a nascent conformer that decreased in abundance as a function of bilayer cholesterol content. High resolution ion mobility-mass spectrometry data revealed two peaks in the ADH region suggesting that ADH populations are composed of two distinct conformers. The conformer preferences of GA dimers from 1,2-distearoyl-sn-glycero-3-phosphocholine bilayers were significantly different for samples incubated at 4°C vs. 60°C; increased cholesterol content yielded more PDH and SSHH at 60°C. The addition of cholesterol as well as incubating samples of 1,2-distearoyl-sn-glycero-3-phosphocholine at 60°C for 24-72 h yielded an increase in PDH and SSHH abundance. PMID:27119642

  18. Structure of Human Pancreatic Lipase-Related Protein 2 with the Lid in an Open Conformation

    SciTech Connect

    Eydoux, Cecilia; Spinelli, Silvia; Davis, Tara L.; Walker, John R.; Seitova, Alma; Dhe-Paganon, Sirano; De Caro, Alain; Cambillau, Christian; Carriere, Frederic

    2008-10-02

    Access to the active site of pancreatic lipase (PL) is controlled by a surface loop, the lid, which normally undergoes conformational changes only upon addition of lipids or amphiphiles. Structures of PL with their lids in the open and functional conformation have required cocrystallization with amphiphiles. Here we report two crystal structures of wild-type and unglycosylated human pancreatic lipase-related protein 2 (HPLRP2) with the lid in an open conformation in the absence of amphiphiles. These structures solved independently are strikingly similar, with some residues of the lid being poorly defined in the electron-density map. The open conformation of the lid is however different from that previously observed in classical liganded PL, suggesting different kinetic properties for HPLRP2. Here we show that the HPLRP2 is directly inhibited by E600, does not present interfacial activation, and acts preferentially on substrates forming monomers or small aggregates (micelles) dispersed in solution like monoglycerides, phospholipids and galactolipids, whereas classical PL displays reverse properties and a high specificity for unsoluble substrates like triglycerides and diglycerides forming oil-in-water interfaces. These biochemical properties imply that the lid of HPLRP2 is likely to spontaneously adopt in solution the open conformation observed in the crystal structure. This open conformation generates a large cavity capable of accommodating the digalactose polar head of galactolipids, similar to that previously observed in the active site of the guinea pig PLRP2, but absent from the classical PL. Most of the structural and kinetic properties of HPLRP2 were found to be different from those of rat PLRP2, the structure of which was previously obtained with the lid in a closed conformation. Our findings illustrate the essential role of the lid in determining the substrate specificity and the mechanism of action of lipases.

  19. Conformational preferences and synthesis of isomers Z and E of oxazole-dehydrophenylalanine.

    PubMed

    Staś, Monika; Bujak, Maciej; Broda, Małgorzata A; Siodłak, Dawid

    2016-05-01

    Dehydrophenylalanine, ΔPhe, is the most commonly studied α,β-dehydroamino acid. In nature, further modifications of the α,β-dehydroamino acids were found, for example, replacement of the C-terminal amide group by oxazole ring. The conformational properties of oxazole-dehydrophenylalanine residue (ΔPhe-Ozl), both isomers Z and E, were investigated. To determine all possible conformations, theoretical calculations were performed using Ac-(Z/E)-ΔPhe-Ozl(4-Me) model compounds at M06-2X/6-31++G(d,p) level of theory. Ac-(Z/E)-ΔPhe-Ozl-4-COOEt compounds were synthesized and the conformational preferences of each isomer, Z and E, were investigated using FTIR and NMR-NOE in solutions of increasing polarity (CHCl3 , DMSO-d6). The solid-state low-temperature structures of Ac-(Z)-ΔPhe-Ozl-4-COOEt and its intermediate analog Ac-(Z)-ΔPhe-Ozn(4-OH)-4-COOEt were also determined. In a weakly polar environment, the ΔPhe-Ozl residue has a tendency to adopt the conformation β2 with the calculated φ and ψ angles of -127° and 0° for the isomer Z and -170° and 26° for the isomer E. The increase of environment polarity favors the helical conformation α and the beta-turn like conformation β, but the conformation β2 seems to be still accessible. The (E)-ΔPhe-Ozl residue can be obtained from the isomer Z in photoisomerization reaction. However, hydroxyl-oxazoline-dehydrophenylalanine ΔPhe-Ozn(4-OH) decomposes in such conditions. Alternatively, (E)-ΔPhe-NH2 can be applied as a substrate in the Hantzsch reaction. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 283-294, 2016. PMID:27061820

  20. Capturing Conformation-Dependent Molecule-Surface Interactions When Surface Chemistry Is Heterogeneous.

    PubMed

    Mabry, Joshua N; Kastantin, Mark; Schwartz, Daniel K

    2015-07-28

    Molecular building blocks, such as carbon nanotubes and DNA origami, can be fully integrated into electronic and optical devices if they can be assembled on solid surfaces using biomolecular interactions. However, the conformation and functionality of biomolecules depend strongly on the local chemical environment, which is highly heterogeneous near a surface. To help realize the potential of biomolecular self-assembly, we introduce here a technique to spatially map molecular conformations and adsorption, based on single-molecule fluorescence microscopy. On a deliberately patterned surface, with regions of varying hydrophobicity, we characterized the conformations of adsorbed helicogenic alanine-lysine copeptides using Förster resonance energy transfer. The peptides adopted helical conformations on hydrophilic regions of the surface more often than on hydrophobic regions, consistent with previous ensemble-averaged observations of α-helix surface stability. Interestingly, this dependence on surface chemistry was not due to surface-induced unfolding, as the apparent folding and unfolding dynamics were usually much slower than desorption. The most significant effect of surface chemistry was on the adsorption rate of molecules as a function of their initial conformational state. In particular, regions with higher adsorption rates attracted more molecules in compact, disordered coil states, and this difference in adsorption rates dominated the average conformation of the ensemble. The correlation between adsorption rate and average conformation was also observed on nominally uniform surfaces. Spatial variations in the functional state of adsorbed molecules would strongly affect the success rates of surface-based molecular assembly and can be fully understood using the approach developed in this work. PMID:26079177