Science.gov

Sample records for cap alpha scattering

  1. cap alpha. /sup 4/He elastic scattering at high energies

    SciTech Connect

    Usmani, A.A.; Ahmad, I.; Usmani, Q.N.

    1989-03-01

    Differential cross sections for ..cap alpha.. /sup 4/He elastic scattering have been calculated at incident ..cap alpha..-particle momenta of 4.32, 5.07, and 7.0 GeV/c within the framework of Glauber multiple scattering theory. The full Glauber amplitude has been calculated using the Monte Carlo method for evaluating multidimensional integrals. We found that, in general, the more realistic double-Gaussian model for the density brings theory closer to experiment as compared to the generally used single-Gaussian model in some momentum transfer regions. Our results with the double-Gaussian model and an acceptable set of NN parameters are in fairly good agreement with the experimental data at 4.32 and 5.07 GeV/c.

  2. Deconvolution of H-. cap alpha. profiles measured by Thomson scattering collecting optics

    SciTech Connect

    LeBlanc, B.; Grek, B.

    1986-08-01

    A method using a multipoint Thomson scattering system to obtain spatially resolved local emissivity is described. The method involves Fourier decomposition with auxiliary constraints. Optimum solution is determined from an analysis of the entropy and the error of the inversion. The technique is applied to H-..cap alpha.. emission profiles from the PDX tokamak.

  3. Theoretical studies on the physical properties and bonding of the 5d metal hexafluorides using the multiple scattering X. cap alpha. technique

    SciTech Connect

    Bloor, J.E.; Sherrod, R.E.

    1980-06-18

    Nonrelativistic overlapping spheres X..cap alpha.. multiple scattering OSMSX..cap alpha.. calculations have been performed on the 5d heavy metal hexafluorides MF/sub 6/, where M = W, Re, Os, Ir, Pt, and Au, and on MoF/sub 6/ and SF/sub 6/. With the aid of these calculations a consistent interpretation of the ionization potentials (IPs), electron affinities (EAs), and charge transfer (CT) electronic absorption bands for these molecules is obtained. The calculations are also shown to be successful in interpreting molecular properties related to the charge-density distributions. The method is found to be very useful in predicting trends in all the properties across the 5d series. Relativistic effects are discussed, and for the EAs it is found necessary to take into account these effects. After a semiempirical correction factor of approx. 1.0 eV, deduced from the molecular spin-orbit coupling constants is applied, the EAs are found to agree well with the most recent experimental estimates.

  4. Semiphenomenological method of analysis for intermediate-energy alpha-nucleus elastic scattering data

    SciTech Connect

    Ahmad, I.; Alvi, M.A.

    1983-12-01

    We propose a semiphenomenological method of analysis for intermediate energy ..cap alpha..-nucleus elastic scattering experiments and demonstrate its usefulness by analyzing available elastic ..cap alpha..-nucleus scattering data at 1.37 GeV.

  5. H. cap alpha. in RS CVn binaries

    SciTech Connect

    Bopp, B.W.; Talcott, J.C.

    1980-01-01

    The 1976--78 results of a spectroscopic program to monitor H..cap alpha.. in several RS CVn-type binaries are reported. For six objects well observed over orbital phase, four (HR 4665, HR 5110, sigma Gem, Z Her) show H..cap alpha.. as an absorption feature having a constant ( +- 15%) equivalent width (EW). AR Lac exhibits an absorption profile also, but the EW varies by a factor of three due to partial filling by emission. This variation is sporadic and not phase dependent. The H..cap alpha.. feature in HK Lac shows the most extreme variation: normally seen as an absorption feature with variable EW, it has been observed as a pure emission feature on three spectrograms, showing a blueshift with respect to the photosphere of approx.50--100 km sec/sup -1/. On a single occasion HK Lac showed double H..cap alpha.. emission with a separation of the peaks of approx.300 km sec/sup -1/. These high velocity features are interpreted in terms of prominence-like structure in the atmosphere of the active star.

  6. Ab initio alpha-alpha scattering.

    PubMed

    Elhatisari, Serdar; Lee, Dean; Rupak, Gautam; Epelbaum, Evgeny; Krebs, Hermann; Lähde, Timo A; Luu, Thomas; Meißner, Ulf-G

    2015-12-01

    Processes such as the scattering of alpha particles ((4)He), the triple-alpha reaction, and alpha capture play a major role in stellar nucleosynthesis. In particular, alpha capture on carbon determines the ratio of carbon to oxygen during helium burning, and affects subsequent carbon, neon, oxygen, and silicon burning stages. It also substantially affects models of thermonuclear type Ia supernovae, owing to carbon detonation in accreting carbon-oxygen white-dwarf stars. In these reactions, the accurate calculation of the elastic scattering of alpha particles and alpha-like nuclei--nuclei with even and equal numbers of protons and neutrons--is important for understanding background and resonant scattering contributions. First-principles calculations of processes involving alpha particles and alpha-like nuclei have so far been impractical, owing to the exponential growth of the number of computational operations with the number of particles. Here we describe an ab initio calculation of alpha-alpha scattering that uses lattice Monte Carlo simulations. We use lattice effective field theory to describe the low-energy interactions of protons and neutrons, and apply a technique called the 'adiabatic projection method' to reduce the eight-body system to a two-cluster system. We take advantage of the computational efficiency and the more favourable scaling with system size of auxiliary-field Monte Carlo simulations to compute an ab initio effective Hamiltonian for the two clusters. We find promising agreement between lattice results and experimental phase shifts for s-wave and d-wave scattering. The approximately quadratic scaling of computational operations with particle number suggests that it should be possible to compute alpha scattering and capture on carbon and oxygen in the near future. The methods described here can be applied to ultracold atomic few-body systems as well as to hadronic systems using lattice quantum chromodynamics to describe the interactions of

  7. Ab initio alpha-alpha scattering.

    PubMed

    Elhatisari, Serdar; Lee, Dean; Rupak, Gautam; Epelbaum, Evgeny; Krebs, Hermann; Lähde, Timo A; Luu, Thomas; Meißner, Ulf-G

    2015-12-01

    Processes such as the scattering of alpha particles ((4)He), the triple-alpha reaction, and alpha capture play a major role in stellar nucleosynthesis. In particular, alpha capture on carbon determines the ratio of carbon to oxygen during helium burning, and affects subsequent carbon, neon, oxygen, and silicon burning stages. It also substantially affects models of thermonuclear type Ia supernovae, owing to carbon detonation in accreting carbon-oxygen white-dwarf stars. In these reactions, the accurate calculation of the elastic scattering of alpha particles and alpha-like nuclei--nuclei with even and equal numbers of protons and neutrons--is important for understanding background and resonant scattering contributions. First-principles calculations of processes involving alpha particles and alpha-like nuclei have so far been impractical, owing to the exponential growth of the number of computational operations with the number of particles. Here we describe an ab initio calculation of alpha-alpha scattering that uses lattice Monte Carlo simulations. We use lattice effective field theory to describe the low-energy interactions of protons and neutrons, and apply a technique called the 'adiabatic projection method' to reduce the eight-body system to a two-cluster system. We take advantage of the computational efficiency and the more favourable scaling with system size of auxiliary-field Monte Carlo simulations to compute an ab initio effective Hamiltonian for the two clusters. We find promising agreement between lattice results and experimental phase shifts for s-wave and d-wave scattering. The approximately quadratic scaling of computational operations with particle number suggests that it should be possible to compute alpha scattering and capture on carbon and oxygen in the near future. The methods described here can be applied to ultracold atomic few-body systems as well as to hadronic systems using lattice quantum chromodynamics to describe the interactions of

  8. Resonance Raman spectra of. cap alpha. -copper phthalocyanine

    SciTech Connect

    Bovill, A.J.; McConnell, A.A.; Nimmo, J.A.; Smith, W.E.

    1986-02-13

    Raman spectra of ..cap alpha..-copper phthalocyanine (..cap alpha..-CuPc) were recorded at room temperature and at 10 K with excitation wavelengths between 457 and 714 nm. Resonance enhancement was greatest for modes for which the largest displacements were on either the inner five-membered ring of the isoindole groups or the inner macrocycle and consequently assignment of the bands to modes of the entire molecule was possible by comparison with nickel octaethylporphyrin. Four out of five bands resonant in the Q band region and preresonant near the B band absorption region are totally symmetric modes. B band preresonance occurs more strongly with high-frequency modes. At low temperatures, multimode interactions are reduced and profiles were obtained which can be compared with solution profiles of porphyrins. Both Q/sub x/ and Q/sub y/ 0-0 scattering can be identified and a helper mode is evident. A term enhancement predominates, with B/sub 1g/ and B/sub 2g/ modes enhanced because of a Jahn-Teller distortion of the excited state. The resonance studies, together with electronic absorption spectra and published theoretical studies, confirm that the Q band in ..cap alpha..-CuPc is largely due to an allowed ..pi..-..pi..* transition associated mainly with the macrocycle and inner five-membered rings of the isoindole groups. 25 references, 5 figures, 2 tables.

  9. cap alpha. -2 adrenergic receptor: a radiohistochemical study

    SciTech Connect

    Unnerstall, J.R.

    1984-01-01

    ..cap alpha..-2 adrenergic agents have been shown to influence blood pressure, heart rate and other physiological and behavioral functions through interactions with adrenergic pathways within the central nervous system. Pharmacologically relevant ..cap alpha..-1 adrenergic receptors were biochemically characterized and radiohistochemically analyzed in intact tissue sections of the rat and human central nervous system. The anatomical distribution of the ..cap alpha..-2 receptors, labeled with the agonist (/sup 3/H)para-aminoclonidine, verified the concept that ..cap alpha..-2 receptors are closely associated with adrenergic nerve terminals and that ..cap alpha..-2 agents can influence autonomic and endocrine function through an action in the central nervous system. Since ..cap alpha..-2 agonists can influence sympathetic outflow, ..cap alpha..-2 binding sites were closely analyzed in the intermediolateral cell column of the thoracic spinal cord. The transport of putative presynaptic ..cap alpha..-2 binding sites in the rat sciatic nerve was analyzed by light microscopic radiohistochemical techniques. Finally, in intact tissue section of the rat central nervous system, the biochemical characteristics of (/sup 3/H)rauwolscine binding were analyzed. Data were also shown which indicates that the synthetic ..cap alpha..-2 antagonist (/sup 3/H)RX781094 also binds to ..cap alpha..-2 receptors with high-affinity. Further, the distribution of (/sup 3/H)RX781094 binding sites in the rat central nervous system was identical to the distribution seen when using (/sup 3/H)para-aminoclonidine.

  10. MFTF-. cap alpha. + T progress report

    SciTech Connect

    Nelson, W.D.

    1985-04-01

    Early in FY 1983, several upgrades of the Mirror Fusion Test Facility (MFTF-B) at Lawrence Livermore National Laboratory (LLNL) were proposed to the fusion community. The one most favorably received was designated MFTF-..cap alpha..+T. The engineering design of this device, guided by LLNL, has been a principal activity of the Fusion Engineering Design Center during FY 1983. This interim progress report represents a snapshot of the device design, which was begun in FY 1983 and will continue for several years. The report is organized as a complete design description. Because it is an interim report, some parts are incomplete; they will be supplied as the design study proceeds. As described in this report, MFTF-..cap alpha..+T uses existing facilities, many MFTF-B components, and a number of innovations to improve on the physics parameters of MFTF-B. It burns deuterium-tritium and has a central-cell Q of 2, a wall loading GAMMA/sub n/ of 2 MW/m/sup 2/ (with a central-cell insert module), and an availability of 10%. The machine is fully shielded, allows hands-on maintenance of components outside the vacuum vessel 24 h after shutdown, and has provisions for repair of all operating components.

  11. Anisotropic. cap alpha. -emission of on-line separated isotopes

    SciTech Connect

    Wouters, J.; Vandeplassche, D.; van Walle, E.; Severijns, N.; Van Haverbeke, J.; Vanneste, L.

    1987-12-10

    The technical realization of particle detection at very low temperatures (4K) has made it possible to study for the first time the anisotropic ..cap alpha..-decay of oriented nuclei which have been produced, separated and implanted on line. The measured ..cap alpha..-angular distributions reveal surprising new results on nuclear aspects as well as in solid state physics. The nuclear structure information from these data questions the older ..cap alpha..-decay theoretical interpretation and urges for a reaxamination of the earliest work on anisotropic ..cap alpha..-decay.

  12. Adsorption properties of. cap alpha. -modification of boron nitride

    SciTech Connect

    Gavrilova, T.B.; Kiselev, A.V.; Parshina, I.V.; Roshchina, T.M.

    1986-11-01

    The adsorption properties of four samples of ..cap alpha..-BN were studied by means of gas chromatography. The particles of ..cap alpha..-BN particles, according to data obtained by electron microscopy, have the shape of thin platelets. A sample of ..cap alpha..-BN prepared from magnesium polyboride was found to be the most nearly homogeneous adsorbent. For a number of n-alkanes, benzene, and alkylbenzenes, data have been obtained on the retention volumes (Henry constants) and the differential heats of adsorption for surface coverages approaching zero. These thermodynamic data on the adsorption showed that ..cap alpha..-BN, like graphitized thermal carbon black, is a nonspecific adsorbent.

  13. cap alpha. -skeletal and. cap alpha. -cardiac actin genes are coexpressed in adult human skeletal muscle and heart

    SciTech Connect

    Gunning, P.; Ponte, P.; Blau, H.; Kedes, L.

    1983-11-01

    The authors determined the actin isotypes encoded by 30 actin cDNA clones previously isolated from an adult human muscle cDNA library. Using 3' untranslated region probes, derived from ..cap alpha.. skeletal, ..beta..- and ..gamma..-actin cDNAs and from an ..cap alpha..-cardiac actin genomic clone, they showed that 28 of the cDNAs correspond to ..cap alpha..-skeletal actin transcripts. Unexpectedly, however, the remaining two cDNA clones proved to derive from ..cap alpha..-cardiac actin mRNA. Sequence analysis confirmed that the two skeletal muscle ..cap alpha..-cardiac actin cDNAs are derived from transcripts of the cloned ..cap alpha..-cardiac actin gene. Comparison of total actin mRNA levels in adult skeletal muscle and adult heart revealed that the steady-state levels in skeletal muscle are about twofold greater, per microgram of total cellular RNA, than those in heart. Thus, in skeletal muscle and in heart, both of the sarcomeric actin mRNA isotypes are quite abundant transcripts. They conclude that ..cap alpha..-skeletal and ..cap alpha..-cardiac actin genes are coexpressed as an actin pair in human adult striated muscles. Since the smooth-muscle actins (aortic and stomach) and the cytoplasmic actins (..beta.. and ..gamma..) are known to be coexpressed in smooth muscle and nonmuscle cells, respectively, they postulate that coexpression of actin pairs may be a common feature of mammalian actin gene expression in all tissues.

  14. Trafficking of. cap alpha. -L-fucosidase in lymphoid cells

    SciTech Connect

    DiCioccio, R.A.; Brown, K.S.

    1987-05-01

    The quantity of ..cap alpha..-L-fucosidase in human serum is determined by heredity. The mechanism controlling levels of the enzyme in serum is unknown. To investigate this, lymphoid cell lines derived from individuals with either low, intermediate or high ..cap alpha..-L-fucosidase in serum were established. Steady state levels of extracellular ..cap alpha..-L-fucosidase protein and activity overlapped among the cell lines. Thus, in vivo serum phenotypes of ..cap alpha..-L-fucosidase are not adequately expressed in this system. ..cap alpha..-L-Fucosidase was also metabolically labelled with /sup 35/S-methionine, immunoprecipitated, and examined by SDS-PAGE. Cells pulse-labelled from 0.25-2 h had a major intracellular form of enzyme (Mr = 58,000). Cells pulsed for 1.5 h and chased for 21 h with unlabeled methionine had an intracellular form of Mr = 60,000 and an extracellular form of Mr = 62,000. Cells treated with chloroquine had only the 58,000-form both intra- and extra-cellularly. Moreover, chloroquine did not effect the quantitative distribution of ..cap alpha..-L-fucosidase between cells and medium. In fibroblasts, chloroquine enhanced the secretion of newly made lysosomal enzymes and blocked the processing of intercellular enzyme forms from a higher to a lower molecular mass. Thus, there are trafficking differences between ..cap alpha..-L-fucosidase in lymphoid cells and lysosomal enzymes in fibroblasts. This suggests that alternative targeting mechanisms for lysosomal enzymes exist in these cells.

  15. Systematics of. cap alpha. decay of even--even isotones

    SciTech Connect

    Poplavskii-breve, I.V.

    1987-02-01

    On the basis of an analysis of experimental data we have investigated for the first time the ..cap alpha.. decay of even--even isotones. We have established that the ..cap alpha..-decay energy of isotones depends on the number of protons approximately according to a linear law. We have shown that the Geiger--Nuttall law is valid both for isotopes and isobars, and also for isotones. The deviations from the Geiger--Nuttall law are due to the shell structure of the nucleus. The regularities observed in the ..cap alpha.. decay of isotones have been used to estimate the magnitudes of the ..cap alpha..-decay energies, the kinetic energies of the emitted ..cap alpha.. particles, and the partial half-lives for ..cap alpha.. decay of the known and unknown neutron--deficient nuclei /sup 202//sup ,//sup 204/Ra, /sup 210/Th, /sup 228//sup ,//sup 230/Pu, /sup 234//sup ,//sup 236/Cm, /sup 242//sup ,//sup 244/Fm, /sup 250//sup ,//sup 258/No, and /sup 254//sup ,//sup 256/Ku.

  16. 5. cap alpha. -reductase activity in rat adipose tissue

    SciTech Connect

    Zyirek, M.; Flood, C.; Longcope, C.

    1987-11-01

    We measured the 5 ..cap alpha..-reductase activity in isolated cell preparations of rat adipose tissue using the formation of (/sup 3/H) dihydrotestosterone from (/sup 3/H) testosterone as an endpoint. Stromal cells were prepared from the epididymal fat pad, perinephric fat, and subcutaneous fat of male rats and from perinephric fat of female rats. Adipocytes were prepared from the epididymal fat pad and perinephric fat of male rats. Stromal cells from the epididymal fat pad and perinephric fat contained greater 5..cap alpha..-reductase activity than did the adipocytes from these depots. Stromal cells from the epididymal fat pad contained greater activity than those from perinephric and subcutaneous depots. Perinephric stromal cells from female rats were slightly more active than those from male rats. Estradiol (10/sup -8/ M), when added to the medium, caused a 90% decrease in 5..cap alpha..-reductase activity. Aromatase activity was minimal, several orders of magnitude less than 5..cap alpha..-reductase activity in each tissue studied.

  17. Synthetic peptides used to locate the. cap alpha. -bungarotoxin binding site and immunogenic regions on. cap alpha. subunits of the nicotinic acetylcholine receptor

    SciTech Connect

    Ralston, S.; Sarin, V.; Thanh, H.L.; Rivier, J.; Fox, J.L.; Lindstrom, J.

    1987-06-16

    Synthetic peptides corresponding to 57% of the sequence of ..cap alpha.. subunits of acetylcholine receptors from Torpedo californica electric organ and extending from the NH/sub 2/ to the COOCH terminus have been synthesized. The ..cap alpha..-bungarotoxin binding site on denatured ..cap alpha.. subunits was mapped within the sequence ..cap alpha..185-199 by assaying binding of /sup 125/I-..cap alpha..-bungarotoxin to slot blots of synthetic peptides. Further studies showed that residues in the sequence ..cap alpha..190-194, especially cysteines-..cap alpha..192,193, were critical for binding ..cap alpha..-bungarotoxin. Reduction and alkylation studies suggested that these cysteines must be disulfide linked for ..cap alpha..-bungarotoxin to bind. Binding sites for serum antibodies to native receptors or ..cap alpha.. subunits were mapped by indirect immunoprecipitation of /sup 125/I-peptides. Several antigenic sequences were identified, but a synthetic peptide corresponding to the main immunogenic region (which is highly conformation dependent) was not identified.

  18. Alpha particle collective Thomson scattering in TFTR

    SciTech Connect

    Machuzak, J.S.; Woskov, P.P.; Rhee, D.Y.; Gilmore, J.; Bretz, N.L.; Park, H.K.; Aamodt, R.E.; Cheung, P.Y.; Russell, D.A.; Bindslev, H.

    1993-11-01

    A collective Thomson scattering diagnostic is being implemented on TFTR to measure alpha particle, energetic and thermal ion densities and velocity distributions. A 60 GHz, 0.1-1 kW gyrotron will be used as the transmitter source, and the scattering geometry will be perpendicular to the magnetic field in the extraordinary mode polarization. An enhanced scattered signal is anticipated from fluctuations in the lower hybrid frequency range with this scattering geometry. Millimeter wave collective Thomson scattering diagnostics have the advantage of larger scattering angles to decrease the amount of stray light, and long, high power, modulated pulses to obtain improved signal to noise through synchronous detection techniques.

  19. cap alpha. -Methyl-p-tyrosine shifts circadian temperature rhythms

    SciTech Connect

    Cahill, A.L.; Ehret, C.F.

    1982-09-01

    ..cap alpha..-Methyl-p-tyrosine shifts the acrophase (time of highest temperature) of the circadian temperature rhythm of the rat to earlier or later times of day depending on the phase of the cicadian cycle at which the drug is administered. When ..cap alpha..-methyl-p-tyrosine methyl ester HCl is injected intraperitoneally at a dose of 100 mg/kg late in the projected 8-h light phase, the acrophase of the intraperitoneal temperature rhythm is delayed by up to 3 h.However, when the same dose of drug is given 9-10 h into the projected 16-h dark phase of the daily cycle, the acrophase of the temperature rhythm occurs about 2 h earlier than expected. The times of ..cap alpha..-methyl-p-tyrosine administration leading to maximal phase delays or advances are correlated with the times of minimal and maximal turnover of norepinephrine in the hypothalamus. These results suggest that changing rates of norepinephrine turnover in the hypothalamus may regulate the circadian temperature rhythm in rats. The results also emphasize the fact that the effects of drugs may vary as a function of the time of administration. This fact must be taken into account in pharmacologic testing.

  20. Human hTM. cap alpha. gene: Expression in muscle and nonmuscle tissue

    SciTech Connect

    MacLeod, A.R.; Gooding, C.

    1988-01-01

    The authors isolated a cDNA clone from a human skeletal muscle library which contains the complete protein-coding sequence of a skeletal muscle ..cap alpha..-tropomyosin. This cDNA sequence defines a fourth human tropomyosin gene, the hTM..cap alpha.. gene, which is distinct from the hTM/sub nm/ gene encoding a closely related isoform of skeletal muscle ..cap alpha..-tropomyosin. In cultured human fibroblasts, the hTM..cap alpha.. gene encodes both skeletal-muscle- and smooth-muscle-type ..cap alpha..-tropomyosins by using an alternative mRNA-splicing mechanism.

  1. Alpha-human atrial natriuretic polypeptide (. cap alpha. -hANP) specific binding sites in bovine adrenal gland

    SciTech Connect

    Higuchi, K.; Nawata, H.; Kato, K.I.; Ibayashi, H.; Matsuo, H.

    1986-06-13

    The effects of synthetic ..cap alpha..-human atrial natriuretic polypeptide (..cap alpha..-hANP) on steroidogenesis in bovine adrenocortical cells in primary monolayer culture were investigated. ..cap alpha..-hANP did not inhibit basal aldosterone secretion. ..cap alpha..-hANP induced a significant dose-dependent inhibition of basal levels of cortisol and dehydroepiandrosterone (DHEA) secretion and also of aCTH (10/sup -8/M)-stimulated increases in aldosterone, cortisol and DHEA secretion. Visualization of (/sup 125/I) ..cap alpha..-hANP binding sites in bovine adrenal gland by an in vitro autoradiographic technique demonstrated that these sites were highly localized in the adrenal cortex, especially the zona glomerulosa. These results suggest that the adrenal cortex may be a target organ for direct receptor-mediated actions of ..cap alpha..-hANP.

  2. Human collagen genes encoding basement membrane. cap alpha. 1(IV) and. cap alpha. 2(IV) chains map to the distal long arm of chromosome 13

    SciTech Connect

    Griffin, C.A.; Emanuel, B.S.; Hansen, J.R.; Cavenee, W.K.; Myers, J.C.

    1987-01-01

    At least 20 genes encode the structurally related collagen chains that comprise > 10 homo- or heterotrimeric types. Six members of this multigene family have been assigned to five chromosomes in the human genome. The two type I genes, ..cap alpha..1 and ..cap alpha..2, are located on chromosomes 17 and 7, respectively, and the ..cap alpha..1(II) gene is located on chromosome 12. Their recent mapping of the ..cap alpha..1(III) and ..cap alpha..2(V) genes to the q24.3 ..-->.. q31 region of chromosome 2 provided the only evidence that the collagen genes are not entirely dispersed. To further determine their organization, the authors and others localized the ..cap alpha..1(IV) gene to chromosome 13 and in their experiments sublocalized the gene to band q34 by in situ hybridization. Here they show the presence of the ..cap alpha..2 type IV locus also on the distal long arm of chromosome 13 by hybridizing a human ..cap alpha..2(IV) cDNA clone to rodent-human hybrids and to metaphase chromosomes. These studies represent the only demonstration of linkage between genes encoding both polypeptide chains of the same collagen type.

  3. Affinity chromatography of alpha/sub 2/-adrenergic receptors (. cap alpha. /sub 2/AR) from pig cerebral cortex

    SciTech Connect

    Repaske, M.G.; Limbird, L.E.

    1986-03-01

    A high capacity, ..cap alpha../sub 2/AR-selective affinity resin (YOH. ag) has been prepared by coupling yohimbinic acid to diaminodipropylamine agarose with 1,3 dicyclohexylcarbodiimide. Unreacted amino groups on the agarose matrix are blocked subsequently by acetylation. One volume of YOH. ag adsorbs 75% of the ..cap alpha../sub 2/AR from 50 volumes of digitonin-solubilized preparation containing 0.2 pmol ..cap alpha../sub 2/AR/mg protein. Digitonin-solubilized preparations are derived from cholate extracts of porcine cerebral cortex containing approx. 0.075 pmol ..cap alpha../sub 2/AR/mg protein. Adsorption of ..cap alpha../sub 2/AR to YOH. ag is selective and thus is blocked by the ..cap alpha..-adrenergic antagonist phentolamine. Adsorbed ..cap alpha../sub 2/AR are eluted with 10 ..mu..M phentolamine (20% yield) after removal of non-related proteins with NaCl gradients. Following hydroxylapatite chromatography to concentrate ..cap alpha..''AR and to remove phentolamine, the ..cap alpha..AR is present at 200-400 pmol/mg protein, assayed using sub-saturating concentrations of (/sup 3/H)-yohimbine. (It is estimated that the specific activity of a homogeneous ..cap alpha../sub 2/AR preparation would be 12,000-16,000 pmol/mg protein.) The availability of large quantities of cortical ..cap alpha../sub 2/AR and a resin easily prepared from commercially-supplied reagents suggests that purification of quantities of ..cap alpha../sub 2/AR sufficient for subsequent biochemical studies is feasible.

  4. ACTH and. cap alpha. -melanotropin in central temperature control

    SciTech Connect

    Lipton, J.M.; Glyn, J.R.; Zimmer, J.A.

    1981-11-01

    Adrenocorticotropin (ACTH) and ..cap alpha..-melanotropin (..cap alpha..-MSH) occur in brain tissue known to be important to temperature control. These peptides cause hypothermia if they are injected centrally in sufficient doses, but they do not act on the central set point of temperature control. Instead they appear to inhibit central pathways for heat conservation and production. In addition to their hypothermic capability, these peptides are antipyretic when given centrally in doses that have no effect on normal body temperature. ACTH has previously been associated with fever reduction in both clinical and experimental studies, and it may be that endogenous central ACTH is important for limitation of maximal fever. The hypothermic and antipyretic effects of ACTH do not depend on stimulation of the adrenal cortex because they are also observed in adrenalectomized rabbits. Nor is the antipyretic effect limited to the rabbit inasmuch as a comparable effect has been demonstrated in the squirrel monkey. The two peptides may be involved in central mediation of normal thermoregulation and fever, perhaps limiting the febrile response and other rises in body temperature by acting as neurotransmitters or neuromodulators in central thermoregulatory pathways.

  5. Concept of a (1-. cap alpha. ) performance confidence interval

    SciTech Connect

    Leong, H.H.; Johnson, G.R.; Bechtel, T.N.

    1980-01-01

    A multi-input, single-output system is assumed to be represented by some model. The distribution functions of the input and the output variables are considered to be at least obtainable through experimental data. Associated with the computer response of the model corresponding to given inputs, a conditional pseudoresponse set is generated. This response can be constructed by means of the model by using the simulated pseudorandom input variates from a neighborhood defined by a preassigned probability allowance. A pair of such pseudoresponse values can then be computed by a procedure corresponding to a (1-..cap alpha..) probability for the conditional pseudoresponse set. The range defined by such a pair is called a (1-..cap alpha..) performance confidence interval with respect to the model. The application of this concept can allow comparison of the merit of two models describing the same system, or it can detect a system change when the current response is out of the performance interval with respect to the previously identified model. 6 figures.

  6. Molecular cloning of the. cap alpha. subunit of human and guinea pig leukocyte adhesion glycoprotein Mo1: Chromosomal localization and homology to the. cap alpha. subunits of integrins

    SciTech Connect

    Arnaout, M.A.; Remold-O'Donnell, E.; Pierce, M.W.; Harris, P.; Tenen, D.G.

    1988-04-01

    The cell surface-glycoprotein Mo1 is a member of the family of leukocyte cell adhesion molecules (Leu-CAMs) that includes lymphocyte function-associated antigen 1 (LFA-1) and p150,95. Each Leu-CAM is a heterodimer with a distinct ..cap alpha.. subunit noncovalently associated with a common ..beta.. subunit. The authors describe the isolation and analysis of two partial cDNA clones encoding the ..cap alpha.. subunit of the Leu-CAM Mo1 in humans and guinea pigs. A monoclonal antibody directed against an epitope in the carboxyl-terminal portion of the guinea pig ..cap alpha.. chain was used for immunoscreening a lambdagt11 expression library. The sequence of a 378-base-pair insert from one immunoreactive clone revealed a single continuous open reading frame encoding 126 amino acids including a 26-amino acid tryptic peptide isolated from the purified guinea pig ..cap alpha.. subunit. A cDNA clone of identical size was isolated from a human monocyte/lymphocyte cDNA library by using the guinea pig clone as a probe. The human clone also encoded a 126-amino acid peptide including the sequence of an additional tryptic peptide present in purified human Mo1..cap alpha.. chain. Southern analysis of DNA from hamster-human hybrids localized the human Mo1..cap alpha.. chain to chromosome 16, which has been shown to contain the gene for the ..cap alpha.. chain of lymphocyte function-associated antigen 1. These data suggest that the ..cap alpha.. subunits of Leu-CAMs evolved by gene duplication from a common ancestral gene and strengthen the hypothesis that the ..cap alpha.. subunits of these heterodimeric cell adhesion molecules on myeloid and lymphoid cells, platelets, and fibroblasts are evolutionary related.

  7. Alpha resonant scattering for astrophysical reaction studies

    NASA Astrophysics Data System (ADS)

    Yamaguchi, H.; Kahl, D.; Nakao, T.; Wakabayashi, Y.; Kubano, S.; Hashimoto, T.; Hayakawa, S.; Kawabata, T.; Iwasa, N.; Teranishi, T.; Kwon, Y. K.; Binh, D. N.; Khiem, L. H.; Duy, N. G.

    2014-05-01

    Several alpha-induced astrophysical reactions have been studied at CRIB (CNS Radioactive Ion Beam separator), which is a low-energy RI beam separator at Center for Nuclear Study (CNS) of the University of Tokyo. One of the methods to study them is the α resonant scattering using the thick-target method in inverse kinematics. Among the recent studies at CRIB, the measurement of 7Be+α resonant scattering is discussed. Based on the result of the experiment, we evaluated the contributions of high-lying resonances for the 7Be(α,γ) reaction, and proposed a new cluster band in 11C.

  8. Alpha resonant scattering for astrophysical reaction studies

    SciTech Connect

    Yamaguchi, H.; Kahl, D.; Nakao, T.; Wakabayashi, Y.; Kubano, S.; Hashimoto, T.; Hayakawa, S.; Kawabata, T.; Iwasa, N.; Teranishi, T.; Kwon, Y. K.; Binh, D. N.; Khiem, L. H.; Duy, N. G.

    2014-05-02

    Several alpha-induced astrophysical reactions have been studied at CRIB (CNS Radioactive Ion Beam separator), which is a low-energy RI beam separator at Center for Nuclear Study (CNS) of the University of Tokyo. One of the methods to study them is the α resonant scattering using the thick-target method in inverse kinematics. Among the recent studies at CRIB, the measurement of {sup 7}Be+α resonant scattering is discussed. Based on the result of the experiment, we evaluated the contributions of high-lying resonances for the {sup 7}Be(α,γ) reaction, and proposed a new cluster band in {sup 11}C.

  9. Probable new type of reaction mechanism: Double. cap alpha. direct transfer process

    SciTech Connect

    Xu Shu-wei; Wu Guo-hua; Miao Rong-zhi; Han Fei

    1983-10-01

    It is assumed that /sup 8/Be consists of two ..cap alpha.. particles which are close to each other in configuration space. A spectroscopic density of /sup 8/Be cluster in the residue nuclei is then obtained, which is proportional to the square of the preformation probability of ..cap alpha.. particle at nuclear surface. Using the improved method of parametrization of EFR-DWBA overlap integral,/sup 1//sup en-dash//sup 2/ we calculate the double differential energy spectra and angular distributions of ..cap alpha.. particles for the reactions /sup 209/Bi (/sup 12/C, ..cap alpha..) /sup 217/Fr and extract the preformation probability of ..cap alpha.. particle at the surface of /sup 217/Fr nuclei from fitting the experimental data. The agreement within the range of calculation error between the preformation probabilities extracted from transfer reactions and ..cap alpha.. decay suggests that the reaction /sup 209/Bi(/sup 12/C, ..cap alpha..) /sup 217/Fr may be explained as a double ..cap alpha.. direct transfer process.

  10. Improved radioimmunoassay for thymosin. cap alpha. 1 recognizes the N-14 amino terminus

    SciTech Connect

    Naylor, P.H.; Goldstein, A.L.

    1986-03-01

    Thymosin ..cap alpha../sub 1/(T..cap alpha../sub 1/) is a biologically active thymic peptide currently undergoing trials as an immunomodulator in cancer patients and patients with immunodeficiencies. Abnormally elevated levels of T..cap alpha../sub 1/ have been found in the serum of individuals with or at risk for AIDS, with T-cell leukemias, and chronic progressive multiple sclerosis. Absorption of the current antibody with a synthetic C-14 fragment of T..cap alpha../sub 1/ results in an antisera specific for the N-14 amino terminus of T..cap alpha../sub 1/, which measures significantly higher levels of T..cap alpha../sub 1/ in serum from normal individuals and significantly increases the sensitivity of the assay. Ongoing studies indicate that this new RIA for T..cap alpha../sub 1/ will be useful in monitoring changes of immunoreactive T..cap alpha../sub 1/ in serum with age and in patients with known or suspected T-cell abnormalities.

  11. Prostaglandin F/sub 2. cap alpha. activates phosphoinositide hydrolysis in rat aorta

    SciTech Connect

    Not Available

    1986-03-01

    The authors have previously demonstrated that norepinephrine (NE) and serotonin (5HT) activate a phosphoinositide-(PI) specific phospholipase C in rat aorta by interaction with ..cap alpha../sub 1/-adrenergic receptors and 5HT/sub 2/ receptor, respectively. They have subsequently noted that angiotensin II and vasopressin as well activate PI hydrolysis in the tissue. The most active agent they have thus far investigated is prostaglandin F/sub 2..cap alpha../ (PGF/sub 2..cap alpha../). Rat aortic rings were pre-labelled with (/sup 3/H)-inositol and then, in the presence of 10 mM LiCl, exposed to various doses of PGF/sub 2..cap alpha../. (/sup 3/H)-inositol monophosphate was the quantified by anion-exchange chromatography. After a 60 min incubation, PGF/sub 2..cap alpha../ caused a 10-15 fold increase over basal at maximal concentrations (0.1-1.0 mM). An EC/sub 50/ for PI hydrolysis was between 0.1-1.0 ..mu..M. PGF/sub 2..cap alpha../ caused maximal aortic contraction at 10 ..mu..M. PGF/sub 2..cap alpha../-induced PI hydrolysis, was inhibited by phorbol esters. These results suggest that PGF/sub 2..cap alpha../, similar to 5HT, NE, vasopressin and angiotensin II, causes vasoconstriction by activation of PI hydrolysis.

  12. Purification and characterization of the human platelet. cap alpha. /sub 2/-adrenergic receptor

    SciTech Connect

    Shreeve, S.M.; Kerlavage, A.R.; Fraser, C.M.; Mariani, A.P.; Venter, J.C.

    1986-05-01

    The ..cap alpha../sub 2/-receptor (..cap alpha../sub 2/-R) from human platelets has been purified to homogeneity using a four step process. An affinity column was prepared by coupling p-aminoclonidine to CH-Sepharose 4B via the p-NH/sub 2/ group. Digitonin solubilized ..cap alpha../sub 2/-R bound to the affinity matrix were eluted with 100 ..mu..M phentolamine and directly applied to a DEAE-Sepharose column. Bound receptors were eluted with a linear gradient of 0-500 mM NaCl, pooled and chromatographed on HPLC size exclusion columns. Three peaks of ..cap alpha../sub 2/-R binding were eluted from HPLC columns (t = 33, 42, 47 min). Radioiodination of HPLC eluates and analysis by SDS-PAGE indicated that ..cap alpha../sub 2/-R binding was associated with a 75-85 kDa protein. These data suggest that the ..cap alpha../sub 2/-R may exist in monomeric and oligomeric forms in the purified state and support previous target size data which indicate that the ..cap alpha../sub 2/-R exists as a dimer in the native membrane. The pure radioiodinated ..cap alpha../sub 2/-R (77-85 kDa) is a glycoprotein with terminal sialic acid or N-acetylglucosamine residues and has a pI of 4.1 on column isoelectric focusing. These data are consistent with those previously reported on the partially purified ..cap alpha../sub 2/-R. Electron micrographs confirm the oligomeric nature and size of the pure ..cap alpha../sub 2/-R.

  13. Limited proteolysis by macrophage elastase inactivities human. cap alpha. /sub 1/-proteinase inhibitor

    SciTech Connect

    Banda, M.J.; Clark, E.J.; Werb, Z.

    1980-12-01

    Ever since the initial description of ..cap alpha../sub 1/-proteinase inhibitor (..cap alpha../sub 1/PI), the role of this plasma glycoprotein and its allelic polymorphism in disease and in healthy physiology has been the subject of much investigation, ..cap alpha../sub 1/PI inactivates a number of serine proteinases, including granulocyte elastase, and thus affords protection from the connective tissue degradation mediated by this class of proteinases. Because an imbalance in the ratio between ..cap alpha../sub 1/PI and proteinase may contribute to the development of destructive lung diseases, proteinases have been implicated in the pathogenesis of pulmonary emphysema. Both macrophages and polymorphonuclear leukocytes have been implicated in disruption of the ..cap alpha../sub 1/PI-proteinase balance. In this report, a new mechanism for alteration of the ..cap alpha../sub 1/PI-proteinase balance is demonstrated. It was found that the purified form of macrophage elastase catalytically degrades and inactivates ..cap alpha../sub 1/PI so that it no longer inhibits the elastinolytic activity of granulocyte elastase.

  14. Purification and reconstitution of the human platelet. cap alpha. /sub 2/-adrenergic receptor

    SciTech Connect

    Regan, J.W.; Cerione, R.A.; Nakata, H.; Benovic, J.L.; DeMarinis, R.M.; Caron, M.G.; Lefkowitz, R.J.

    1986-05-01

    Human platelet ..cap alpha../sub 2/-adrenergic receptors have been purified approx.80,000 fold to apparent homogeneity by a five step chromatographic procedure. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of radioiodinated protein from purified receptor preparations shows a single major band of M/sub r/ 64,000. The competitive binding of ligands to the purified receptor protein shows the proper ..cap alpha../sub 2/-adrenergic specificity. The ..cap alpha../sub 2/-adrenergic receptor contains an essential sulfhydryl residues. Thus, exposure of the purified receptor to the sulfhydryl specific reagent, phenylmercuric chloride (PMC), resulted in a 80% loss of binding activity. This loss of binding activity was prevented when exposure to PMC was done in the presence of ..cap alpha../sub 2/-adrenergic ligands and it was reversed by subsequent exposure to dithiothreitol. Partial proteolysis of purified ..cap alpha../sub 2/-adrenergic receptors was obtained with S. aureus V-8 protease, ..cap alpha..-chymotrypsin and papain. In a comparison with purified ..beta../sub 2/-adrenergic receptors no common partial proteolytic products were found. Partially purified preparations of the ..cap alpha../sub 2/-adrenergic receptor were successfully reconstituted into phospholipid vesicles with the inhibitory guanyl nucleotide-binding regulatory protein, N/sub i/. In these reconstituted preparations, epinephrine could stimulate, and phentolamine could block, the GTPase activity of N/sub i/.

  15. Membrane transfer of. cap alpha. -tocopherol: influence of soluble. cap alpha. -tocopherol-binding factors from the liver, lung, heart and brain of the rat

    SciTech Connect

    Murphy, D.J.; Mavis, R.D.

    1981-10-25

    The pH of liver supernatant was lowered from 7.4 to 5.1, which removed 23% of the soluble protein and 97% of the lipid-soluble phosphate, increased the total ..cap alpha..-tocopherol transfer activity 1.3-fold and the specific activity of the transfer rate 1.6-fold. This transfer activity was proportional to time up to 4 min and to protein concentrations up to 0.1 mg/ml. Fractionation of the pH 5.1-treated liver supernatant by gel filtration produced a single peak of ..cap alpha..-tocopherol transfer activity of M/sub r/ = 34,000 and a single peak of ..cap alpha..-tocopherol-binding activity which was coincident with the transfer activity. The transfer rate of this peak of activity was 316 pmol/min/mg of protein, a 9-fold purification over the original untreated supernatant. This ..cap alpha..-tocopherol transfer rate was reduced by 83 and 96% following pronase digestion or heat treatment (80/sup 0/C) of the soluble fraction, respectively, while trypsin digestion reduced the transfer rate only 18% and phospholipase C digestion had no effect. Untreated liver supernatant possessed the peak of binding activity of M/sub r/ = 34,000 and a high molecular weight binding fraction that eluted at the void volume. Heart and brain supernatants also possessed an ..cap alpha..-tocopherol-binding fraction that eluted at the void volume, while lung supernatant lacked binding activity.

  16. Increased concentration of. cap alpha. - and. gamma. -endorphin in post mortem hypothalamic tissue of schizophrenic patients

    SciTech Connect

    Wiegant, V.M.; Verhoef, C.J.; Burbach, J.P.H.; de Wied, D.

    1988-01-01

    The concentrations of ..cap alpha..-, ..beta..- and ..gamma..-endorphin were determined by radioimmunoassay in HPLC fractionated extracts of post mortem hypothalamic tissue obtained from schizophrenic patients and controls. The hypothalamic concentration of ..cap alpha..- and ..gamma..-endorphin was significantly higher in patients than in controls. No difference was found in the concentration of ..beta..-endorphin, the putative precursor of ..cap alpha..- and ..gamma..-endorphins. These results suggest a deviant metabolism of ..beta..-endorphin in the brain of schizophrenic patients. Whether this phenomenon is related to the psychopathology, or is a consequence of ante mortem farmacotherapy, remains to be established.

  17. Introduction of the human pro. cap alpha. 1(I) collagen gene into pro. cap alpha. 1(I)-deficient Mov-13 mouse cells leads to formation of functional mouse-human hybrid type I collagen

    SciTech Connect

    Schnieke, A.; Dziadek, M.; Bateman, J.; Mascara, T.; Harbers, K.; Gelinas, R.; Jaenisch, R.

    1987-02-01

    The Mov-13 mouse strain carries a retroviral insertion in the pro..cap alpha..1(I) collagen gene that prevents transcription of the gene. Cell lines derived from homozygous embryos do not express type I collagen although normal amounts of pro..cap alpha..2 mRNA are synthesized. The authors have introduced genomic clones of either the human or mouse pro..cap alpha..1(I) collagen gene into homozygous cell lines to assess whether the human or mouse pro..cap alpha..1(I) chains can associate with the endogenous mouse pro..cap alpha..2(I) chain to form stable type I collagen. The human gene under control of the simian virus 40 promoter was efficiently transcribed in the transfected cells. Protein analyses revealed that stable heterotrimers consisting of two human ..cap alpha..1 chains and one mouse ..cap alpha..2 chain were formed and that type I collagen was secreted by the transfected cells at normal rates. However, the electrophoretic migration of both ..cap alpha..1(I) and ..cap alpha..2(I) chains in the human-mouse hybrid molecules were retarded, compared to the ..cap alpha..(I) chains in control mouse cells. Inhibition of the posttranslational hydroxylation of lysine and proline resulted in comigration of human and mouse ..cap alpha..1 and ..cap alpha..2 chains, suggesting that increased posttranslational modification caused the altered electrophoretic migration in the human-mouse hybrid molecules. Amino acid sequence differences between the mouse and human ..cap alpha.. chains may interfere with the normal rate of helix formation and increase the degree of posttranslational modifications similar to those observed in patients with lethal perinatal osteogenesis imperfecta. The Mov-13 mouse system should allow the authors to study the effect specific mutations introduced in transfected pro..cap alpha..1(I) genes have on the synthesis, assembly, and function of collagen I.

  18. Neutron diffraction of. cap alpha. ,. beta. and. gamma. cyclodextrins: hydrogen bonding patterns

    SciTech Connect

    Hingerty, B.E.; Klar, B.; Hardgrove, G.; Betzel, C.; Saenger, W.

    1983-01-01

    Cyclodextrins (CD's) are torus-shaped molecules composed of six (..cap alpha..), seven (..beta..) or eight (..gamma..) (1 ..-->.. 4) linked glucoses. ..cap alpha..-CD has been shown to have two different structures with well-defined hydrogen bonds, one tense and the other relaxed. An induced-fit-like mechanism for ..cap alpha..-CD complex formation has been proposed. Circular hydrogen bond networks have also been found for ..cap alpha..-CD due to the energetically favored cooperative effect. ..beta..-CD with a disordered water structure possesses an unusual flip-flop hydrogen bonding system of the type O-H H-O representing an equilibrium between two states; O-H O reversible H-O. ..gamma..-CD with a disordered water structure similar to ..beta..-CD also possesses the flip-flop hydrogen bond. This study demonstrates that hydrogen bonds are operative in disordered systems and display dynamics even in the solid state.

  19. Synthetic. cap alpha. subunit peptide 125-147 of human nicotinic acetylcholine receptor induces antibodies to native receptor

    SciTech Connect

    McCormick, D.J.; Griesmann, G.E.; Huang, Z.; Lennon, V.A.

    1986-03-05

    A synthetic peptide corresponding to residues 125-147 of the Torpedo acetylcholine receptor (AChR) ..cap alpha.. subunit proved to be a major antigenic region of the AChR. Rats inoculated with 50 ..mu..g of peptide (T ..cap alpha.. 125-147) developed T cell immunity and antibodies to native AChR and signs of experimental autoimmune myasthenia gravis. They report the synthesis and preliminary testing of a disulfide-looped peptide comprising residues 125-147 of the human AChR ..cap alpha.. subunit. Peptide H ..cap alpha.. 125-147 differs from T ..cap alpha.. 125-147 at residues 139 (Glu for Gln) and 143 (Ser for Thr). In immunoprecipitation assays, antibodies to Torpedo AChR bound /sup 125/I-labelled H..cap alpha.. 125-147 antibody bound H..cap alpha.. 125-147, but monoclonal antibodies to an immunodominant region of native AChR bound neither H..cap alpha.. 125-147 nor T ..cap alpha.. 125-147. Rats immunized with H ..cap alpha.. 125-147 produced anti-mammalian muscle AChR antibodies that induced modulation of AChRs from cultured human myotubes. Thus, region 125-147 of the human AChR ..cap alpha.. subunit is extracellular in muscle, and is both antigenic and immunogenic. It remains to be determined whether or not autoantibodies to this region may in part cause the weakness or myasthenia gravis in man.

  20. New, tritium-release assay for 25-hydroxyvitamin D-1. cap alpha. -hydroxylase

    SciTech Connect

    Brown, A.J.; Perlman, K.; DeLuca, H.F.

    1986-05-01

    A new, rapid assay for 25-hydroxyvitamin D (25-OH-D)-1..cap alpha..-hydroxylase has been developed using 25-OH-(1..cap alpha..-/sup 3/H)D/sub 3/ as substrate. This compound was prepared by reduction of 1-oxo-25-hydroxycyclovitamin D/sub 3/ with (/sup 3/H)NaBH/sub 4/, separation of the 1..cap alpha..- and 1..beta..-hydroxy products by HPLC, subsequent treatments with methylsulfonylchloride and lithium aluminum hydride, cycloreversion, and saponification. The 1..cap alpha..- and 1..beta..-tritiated substrates were tested in the solubilized and reconstituted chick 1..cap alpha..-hydroxylase system. After incubation, the reaction mixture was passed through a reversed phase silica cartridge to separate (/sup 3/H)H/sub 2/O from the labeled substrate. The cartridges were then washed with methanol to elute all vitamin D metabolites, and the amount of 1,25-(OH)/sub 2/(/sup 3/H)D/sub 3/ was measured by HPLC. In addition, identical reaction mixtures using 25-OH-(26,27-/sup 3/H)D/sub 3/ as substrate were extracted and analyzed by HPLC for 1,25-(OH)/sub 2/(/sup 3/H)D/sub 3/. Reactions with 25-OH-(1..cap alpha..-/sup 3/H)D/sub 3/ produced (/sup 3/H)H/sub 2/O comparable to the amount of 1,25-(OH)/sub 2/(26,27-/sup 3/H)D/sub 3/ and negligible (/sup 3/H) in 1,25-(OH)/sub 2/D/sub 3/. Conversely, reactions with 25-OH-(1..beta..-/sup 3/H)D/sub 3/ produced negligible (/sup 3/H)H/sub 2/O but produced 1,25-(OH)/sub 2/(/sup 3/H)D/sub 3/ comparable to that from reactions with 25-OH-(26,27-/sup 3/H)D/sub 3/. The results indicate that 1..cap alpha..-hydroxylation specifically displaces the 1..cap alpha..-hydrogen of 25-OH-D/sub 3/ and that the release of the 1..cap alpha..-/sup 3/H provides an accurate measure of vitamin D 1..cap alpha..-hydroxylation.

  1. Regulation of the synthesis of barley aleurone. cap alpha. -amylase by gibberellic acid and calcium ions

    SciTech Connect

    Jones, R.L.; Carbonell, J.

    1984-09-01

    The effects of gibberellic acid (GA/sub 3/) and calcium ions on the production of ..cap alpha..-amylase and acid phosphatase by isolated aleurone layers of barley (Hordeum vulgare L. cv Himalaya) were studied. Aleurone layers not previously exposed to GA/sub 3/ or CA/sup 2 +/ show qualitative and quantitative changes in hydrolase production following incubation in either GA/sub 3/ or CA/sup 2 +/ or both. In cubation in H/sub 2/O or CA/sup 2 +/ results in the production of low levels of ..cap alpha..-amylase or acid phosphatase. The addition of GA/sub 3/ to the incubation medium causes 10- to 20-fold increase in the amounts of these enzymes released from the tissue, and addition of CA/sup 2 +/ at 10 millimolar causes a further 8- to 9-fold increase in ..cap alpha..-amylase release and a 75% increase in phosphatase release. Production of ..cap alpha..-amylase isoenzymes is also modified by the levels of GA/sub 3/ and CA/sup 2 +/ in the incubation medium. ..cap alpha..-amylase 2 is produced under all conditions of incubation, while ..cap alpha..-amylase 1 appears only when layers are incubated in GA/sub 3/ or GA/sub 3/ plus CA/sup 2 +/. The synthesis of ..cap alpha..-amylases 3 and 4 requires the presence of both GA/sub 3/ and CA/sup 2 +/ in the incubation medium. Laurell rocket immunoelectrophoresis shows that two distinct groups of ..cap alpha..-amylase antigens are present in incubation media of aleurone layers incubated with both GA/sub 3/ and CA/sup 2 +/, while only one group of antigens is found in media of layers incubated in GA/sub 3/ alone. Strontium ions can be substituted for CA/sup 2 +/ in increasing hydrolase production, although higher concentrations of Sr/sup 2 +/ are requried for maximal response. We conclude that GA/sub 3/ is required for the production of ..cap alpha..-amylase 1 and that both GA/sub 3/ and either CA/sup 2 +/ or Sr/sup 2 +/ are required for the production of isoenzymes 3 and 4 of barley aleurone ..cap alpha..-amylase. 22 references, 8

  2. Mammalian. cap alpha. -polymerase: cloning of partial complementary DNA and immunobinding of catalytic subunit in crude homogenate protein blots

    SciTech Connect

    SenGupta, D.N.; Kumar, P.; Zmudzka, B.Z.; Coughlin, S.; Vishwanatha, J.K.; Robey, F.A.; Parrott, C.; Wilson, S.H.

    1987-02-10

    A new polyclonal antibody against the ..cap alpha..-polymerase catalytic polypeptide was prepared by using homogeneous HeLa cell..cap alpha..-polymerase. The antibody neutralized ..cap alpha..-polymerase activity and was strong and specific for the ..cap alpha..-polymerase catalytic polypeptide (M/sub r/ 183,000) in Western blot analysis of crude extracts of HeLa cells. The antibody was used to screen a cDNA library of newborn rat brain poly(A+) RNA in lambdagt11. A positive phage was identified and plaque purified. This phage, designated lambdapol..cap alpha..1.2, also was found to be positive with an antibody against Drosophila ..cap alpha..-polymerase. The insert in lambdapol..cap alpha..1.2 (1183 base pairs) contained a poly(A) sequence at the 3' terminus and a short in-phase open reading frame at the 5' terminus. A synthetic oligopeptide (eight amino acids) corresponding to the open reading frame was used to raise antiserum in rabbits. Antibody affinity purified from this serum was found to be immunoreactive against purified ..cap alpha..-polymerase by enzyme-linked immunosorbent assay and was capable of immunoprecipitating ..cap alpha..-polymerase. This indicated the lambdapol..cap alpha..1.2 insert encoded an ..cap alpha..-polymerase epitope and suggested that the cDNA corresponded to an ..cap alpha..-polymerase mRNA. This was confirmed in hybrid selection experiments using pUC9 containing the cDNA insert and poly(A+) RNA from newborn rat brain; the insert hybridized to mRNA capable of encoding ..cap alpha..-polymerase catalytic polypeptides. Northern blot analysis of rat brain poly(A+) RNA revealed that this mRNA is approx.5.4 kilobases.

  3. Functional properties of an isolated. cap alpha beta. heterodimeric human placenta insulin-like growth factor 1 receptor complex

    SciTech Connect

    Feltz, S.M.; Swanson, M.L.; Wemmie, J.A.; Pessin, J.E.

    1988-05-03

    Treatment of human placenta membranes at pH 8.5 in the presence of 2.0 mM dithiothreitol (DTT) for 5 min, followed by the simultaneous removal of the DTT and pH adjustment of pH 7.6, resulted in the formation of a functional ..cap alpha beta.. heterodimeric insulin-like growth factor 1 (IGF-1) receptor complex from the native ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric disulfide-linked state. The membrane-bound ..cap alpha beta.. heterodimeric complex displayed similar curvilinear /sup 125/I-IGF-1 equilibrium binding compared to the ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric complex. /sup 125/I-IGF-1 binding to both the isolated ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric and ..cap alpha beta.. heterodimeric complexes demonstrated a marked straightening of the Scatchard plots, compared to the placenta membrane-bound IGF-1 receptors, with a 2-fold increase in the high-affinity binding component. IGF-1 stimulation of IGF-1 receptor autophosphorylation indicated that the ligand-dependent activation of ..cap alpha beta.. heterodimeric protein kinase activity occurred concomitant with the reassociation into a covalent ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric state. These data demonstrate that (i) a combination of alkaline pH and DTT treatment of human placenta membranes results in the formation of an ..cap alpha beta.. heterodimeric IGF-1 receptor complex, (ii) unlike the insulin receptor, high-affinity homogeneous IGF-1 binding occurs in both the ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric and ..cap alpha beta.. heterodimeric complexes, and (iii) IGF-1-dependent autophosphorylation of the ..cap alpha beta.. heterodimeric IGF-1 receptor complex correlates wit an IGF-1 dependent covalent reassociation into an ..cap alpha../sub 2/..beta../sub 2/ heterotetrameric disulfide-linked state.

  4. Identification and subcellular localization of a 21-kilodalton molecule using affinity-purified antibodies against. cap alpha. -transforming growth factor

    SciTech Connect

    Hazarika, P.; Pardue, R.L.; Earls, R.; Dedman, J.R.

    1987-04-07

    Monospecific antibodies were generated against each of six different peptide sequences derived from rat and human ..cap alpha..-transforming growth factor (..cap alpha..-TGF). The affinity-purified antibody to the 17 amino acid carboxyl-terminal portion of the molecule proved most useful in detecting ..cap alpha..-TGF. When used in a peptide-based radioimmunoassay, it was possible to measure nanogram quantities of native ..cap alpha..-TGF in conditioned cell culture media. When used to analyze cell lysate, these antibodies specifically recognized a 21-kilodalton protein species. Indirect immunofluorescence localization procedures revealed a high concentration of ..cap alpha..-TCF in a perinuclear ring with a diffuse cytoplasmic distribution. These results suggest that a precursor form of ..cap alpha..-TGF has a cellular role beyond that of an autocrine growth factor.

  5. Electron-transfer photochemistry of. cap alpha. -silylamine-cyclohexenone systems. Medium effects on reaction pathways followed

    SciTech Connect

    Yoon, U.C.; Kim, J.U.; Hasegawa, E.; Mariano, P.S.

    1987-07-08

    Previously, the authors demonstrated how photostimulated electron-transfer (SET) processes of ..cap alpha..-trialkylsilyl-substituted electron donors can be employed to generate free radical systems. Initial efforts focused on SET processes of iminium salts. Recently, the authors expanded this methodology to include arenecarbonitriles. In this communication they report on the SET photochemistry of ..cap alpha..,..beta..-unsaturated cyclohexenones with an ..cap alpha..-silyl tertiary amine donor.

  6. Device for uniform. cap alpha. irradiation of solid powders

    SciTech Connect

    Orlenev, P.O.; Mel'nikov, P.V.

    1988-08-01

    A device for uniform irradiation of solid powders by alpha particles is described. Uniformity of irradiation is achieved by regular stirring of the specimen on the surface of the alpha source. Polonium 210 serves as the alpha source. A method is described that reduces by a factor of approx. 3 the error in determination of the dose absorbed by a powdered specimen and eliminates irradiation nonuniformity. The effect of heterogeneity saturation on measurements of the radiation properties of the electron-hole centers was checked by study of the dose dependencies of Al/sup 3+/-O/sup -/ and D' centers in quartz.

  7. Characterization of. cap alpha. /sub 2/-adrenergic receptors in rat cerebral cortex

    SciTech Connect

    Nasseri, A.

    1987-01-01

    The properties of /sup 3/H-RX 781094 binding sites and the receptors inhibiting norepinephrine (NE) release and cyclic AMP accumulation in rat cerebral cortex were compared. /sup 3/H-RX 781094, a new ..cap alpha../sub 2/-adrenergic receptor antagonist radioligand, labelled a homogeneous population of binding sites at 37/sup 0/C with the pharmacological specificity expected of ..cap alpha../sub 2/-adrenergic receptors. Gpp(NH)p and NaCl decreased the potencies of agonists at /sup 3/H-RX 781094 binding sites 3-22 fold. Antagonists blocked the inhibition of potassium-evoked tritium release from cortical slices preloaded with /sup 3/H-NE by exogenous NE with potencies similar to those observed in competition for specific /sup 3/H-RX 781094 binding sites. EEDQ, an irreversible ..cap alpha../sub 2/-adrenergic receptors and determine whether there was a receptor reserve for the inhibition of tritium release.

  8. cap alpha. -Methylglucoside satisfies only Na/sup +/-dependent transport system of intestinal epithelium

    SciTech Connect

    Kimmich, G.A.; Randles, J.

    1981-01-01

    The unidirectional influx of ..cap alpha..-methylglucoside (..cap alpha..-MG) by isolated chicken intestinal epithelial cells is 98% inhibited by phlorizin. The remaining 2% of the total influx occurs in the absence of Na/sup +/, is not sensitive to phloretin, and is equal to the diffusional entry rate for 2-deoxyglucose. The glucoside is much more strongly accumulated (75-fold) than 3-O-methylglucose (3-OMG) (10-fold). Inhibitors of the serosal sugar carrier (phloretin, cytochalasin B, theophylline, and flavanoids) do not enhance ..cap alpha..-MG accumulation. It is concluded that the glycoside is not a substrate for the intestinal serosal transport system. Steady-state gradients of the sugar can be represented accurately by a concentrative, phlorizin-sensitive system that is opposed by a diffusional efflux process.

  9. Sequence heterogeneity, multiplicity, and genomic organization of. cap alpha. - and. beta. -tubulin genes in Sea Urchins

    SciTech Connect

    Alexandraki, D.; Ruderman, J.V.

    1981-12-01

    The authors analyzed the multiplicity, heterogeneity, and organization of the genes encoding the ..cap alpha.. and ..beta.. tubulins in the sea urchin Lytechinus pictus by using cloned complementary deoxyribonucleic acid (cDNA) and genomic tubulin sequences. cDNA clones were constructed by using immature spermatogenic testis polyadenylic acid-containing ribonucleic acid as a template. ..cap alpha.. and ..beta..-tubulin clones were identified by hybrid selection and in vitro translation of the corresponding messenger ribonucleic acids, followed by immunoprecipitation and two-dimensional gel electrophoresis of the translation products. The ..cap alpha.. cDNA clone contains a sequence that encodes the 48 C-terminal amino acids of ..cap alpha.. tubulin and 104 base pairs of the 3' nontranslated portion of the messenger ribonucleic acid. The ..beta.. cDNA insertion contains the coding sequence for the 100 C-terminal amino acids of ..beta.. tubulin and 83 base pairs of the 3' noncoding sequence. Hybrid selections performed at different criteria demonstrated the presence of several heterogeneous, closely related tubulin messenger ribonucleic acids, suggesting the existence of heterogeneous ..cap alpha..- and ..beta..-tubulin genes. Hybridization analyses indicated that there are at least 9 to 13 sequences for each of the two tubulin gene families per haploid genome. Hybridization of the cDNA probes to both total genomic DNA and cloned germline DNA fragments gave no evidence for close physical linkage of ..cap alpha..-tubulin genes with ..beta..-tubulin genes at the DNA level. In contrast, these experiments indicated that some genes within the same family are clustered.

  10. Two renal. cap alpha. /sub 2/-adrenergic receptor sites revealed by of-aminoclonidine binding

    SciTech Connect

    Sripanidkulchai, B.; Dawson, R.; Oparil, S.; Wyss, J.M.

    1987-02-01

    (/sup 3/H)p-aminoclonidine (/sup 3/H)PAC, a specific ..cap alpha../sub 2/-adrenergic agonist, was used to characterize ..cap alpha../sub 2/-adrenoceptor binding in rat renal membranes. Rosenthal plots demonstrated two binding sites with K/sub dS/ of approx. 1.7 and 14.2 nM and B/sub max/S (maximum binding) of 47.3 and 218.8 fmol/mg protein for the high- and low-affinity sites, respectively. These characteristics were confirmed by estimate of K/sub d/ parameters based on association and dissociation experiments. Pseudo-Hill coefficients generated from drug inhibition experiments were all less than unity, suggesting differential binding at two ..cap alpha../sub 2/-adrenoceptor binding sites. Specific ..cap alpha../sub 2/-adrenergic agonists exhibited greater binding affinity to both sites than did nonspecific drugs, and all drugs displayed greater affinity for the high- than the low-affinity binding site. Both guanyl nucleotides and sodium chloride inhibited (/sup 3/H)PAC binding more at the high-affinity than at the low-affinity site. Renal denervation resulted in significant upregulation of receptor density only at the high-affinity sites with no change in receptor affinity at either site, suggesting that a majority of the ..cap alpha../sub 2/-adrenoceptors in the kidney are postsynaptic. Thus all lines of evidence in this study indicate that two ..cap alpha../sub 2/-adrenoceptor binding sites exist in the rat kidney.

  11. Affinity alkylators, 11. cap alpha. -bromoacetoxyprogesterone and estrone 3-bromoacetate, modify a common active site-histidine in human placental 17. beta. ,20-. cap alpha. -hydroxysteroid dehydrogenase

    SciTech Connect

    Thomas, J.L.; Asibey-Berko, E.; Strickler, R.C.

    1986-03-01

    Purified human placental 17..beta..,20..cap alpha..-hydroxysteroid dehydrogenase (17,20-HSD), after complete inactivation by estrone 3-bromoacetate (3-BAE) in the presence of NADPH, was reactivated to 100% activity by base-catalyzed hydrolysis of the steroidal ester-enzyme conjugate and then repurified. Computer modeling predicted that 3-BAE and 11..cap alpha..-bromoacetoxyprogesterone (11-BAP) alkylate a common region of the enzyme active site. Kinetic studies argued that reactivated enzyme (RE) and native enzyme (NE) bind 11-BAP in the same orientation. 11-/sup 14/C-BAP produced 5-fold less radiolabeled 3-(carboxymethyl)histidine (3-CM-His) in RE than in NE. Despite having the same affinity for RE and NE, 11-BAP re-inactivated RE5-fold slower than NE. These results demonstrate that the nonradiolabeled 3-CM-His originally produced by 3-BAE in the enzyme active site hindered radioalkylation of this histidyl reside in RE by 11-/sup 14/C-BAP. Thus, 11-BAP and 3-BAE modify a common histidine in the enzyme active site, and this is direct evidence that the estradiol 17..beta..-dehydrogenase and 20..cap alpha..-hydroxysteroid dehydrogenase activities of 17,20-HSD reside at a single locus on one protein.

  12. H/sub. cap alpha. / laser fluorescence diagnostic on the Tara Tandem Mirror experiment

    SciTech Connect

    Guss, W.C.; Yao, X.Z.; Pocs, L.; Mahon, R.; Casey, J.; Post, R.S.

    1988-08-01

    A laser fluorescence diagnostic has been used for measuring the neutral hydrogen density in the central cell of the Tara thermal barrier tandem mirror. Experiments have been performed using laser-induced, resonance fluorescence detection of H/sub ..cap alpha../ (6563-A) radiation. Measurements were made at a number of radial positions with 1-cm resolution, from the magnetic axis to near the plasma limiter. Stray laser light contributions to the signal were eliminated with a double-pulse technique. For comparison, the chord-averaged plasma H/sub ..cap alpha../ radiation was analyzed under the identical conditions for which laser fluorescence data were taken.

  13. Cardiovascular and endocrine response to hemorrhage after. cap alpha. /sub 1/-blockade in lambs and ewes

    SciTech Connect

    Block, S.M.; Rose, J.C.; Ernest, J.M.; Flowe, K.; South, S.; Zimmerman, C.

    1987-02-01

    To evaluate the role of the ..cap alpha../sub 1/-adrenergic system in the response to hemorrhage during development, lambs and adult sheep were chronically catheterized and hemorrhaged after pretreatment with prazosin or vehicle. The adults became markedly more hypotensive after ..cap alpha../sub 1/-blockade and hemorrhage than after vehicle and hemorrhage, whereas the lambs were no more hypotensive when hemorrhaged after prazosin. In the adults and the lambs hemorrhage produced elevations in plasma renin activity and arginine vasopressin measured by radioimmunoassay. However, after prazosin, the adults had a far greater increase in arginine vasopressin levels than after vehicle treatment.

  14. Alpha inelastic scattering and cluster structures in {sup 24}Mg

    SciTech Connect

    Kawabata, T.; Ishiguro, Y.; Nozawa, Y.; Tomida, N.; Yokota, N.; Adachi, T.; Fujiwara, M.; Hatanaka, K.; Tamii, A.; Yasuda, Y.; Zenihiro, J.; Itoh, M.; Takahashi, T.; Yoshida, H. P.; Maeda, Y.; Miyasako, H.; Saito, T.; Matsubara, H.; Sasamoto, Y.; Tokieda, H.

    2011-05-06

    The alpha inelastic scattering from {sup 24}Mg was measured to obtain the isoscalar natural-parity excitation strengths and to search for the {alpha}-condensed states. The multipole decomposition analysis for the measured cross sections was performed. The strength distributions for the {Delta}L = 0-3 were successfully obtained and the possible candidates for the {alpha}-condensed states around the {sup 16}O core were found.

  15. Photoaffinity labeling of human platelet and rabbit kidney. cap alpha. -adrenoceptors with (/sup 3/H)SKF 102229

    SciTech Connect

    Regan, J.W.; Raymond, J.R.; Lefkowitz, R.J.; DeMarinis, R.M.

    1986-06-13

    A newly developed ..cap alpha../sub 2/-adrenergic photoaffinity ligand, 3-methyl-6-chloro-9-azido-1H-2,3,4,5-tetrahydro-3-benzazepine (SKF 102229), has been radiolabeled with tritium to a specific activity of approx. 80 Ci/mmol. Using membranes prepared from human platelets and from rabbit kidney, ..cap alpha../sub 2/-adrenoceptors have been covalently labeled following photolysis in the presence of (/sup 3/H)SKF 102229. As determined by SDS-PAGE, the apparent molecular weight of ..cap alpha../sub 2/-adrenoceptors from both of these tissues was 64,000. The yield of covalent insertion of (/sup 3/H)SKF 102229 into the ..cap alpha../sub 2/-adrenoceptor was very good. Thus, following photolysis up to 90% of the ..cap alpha../sub 2/-adrenoceptors could be irreversibly labeled with (/sup 3/H)SKF 102229.

  16. Enzymatic preparation of. cap alpha. - and. beta. -deuterated or tritiated amino acids with l-methionine. gamma. -lyase

    SciTech Connect

    Esaki, N.; Sawada, S.; Tanaka, H.; Soda, K.

    1982-01-15

    L-Methionine ..gamma..-lyase catalyzes the exchange of ..cap alpha..- and ..beta..-hydrogens of L-methionine and S-methyl-L-cysteine with deuterium or tritium of solvents. The rate of ..cap alpha..-hydrogen exchange with deuterium was about 40 times faster than that of the elimination reactions. The deuterium and tritium were exchanged also with the ..cap alpha..- and ..beta..-hydrogens of the straight-chain amino acids which do not undergo the elimination: L-alanine, L-..cap alpha..-aminobutyrate, L-norvaline, and L-norleucine. No exchange occurs for the D-isomers, acidic L-amino acids, basic L-amino acids, and branched-chain L-amino acids, although ..cap alpha..-hydrogen of glycine, L-trypotophan, and L-phenylalanine is exchanged slowly. These enzymatic hydrogen-exchange reactions facilitate specific labeling of the L-amino acids with deuterium and tritium.

  17. Rocket borne solar eclipse experiment to measure the temperature structure of the solar corona via lyman-. cap alpha. line profile observations

    SciTech Connect

    Argo, H.V.

    1981-01-01

    A rocket borne experiment to measure the temperature structure of the inner solar corona via the doppler broadening of the resonance hydrogen Lyman-..cap alpha.. (lambda1216A) radiation scattered by ambient neutral hydrogen atoms was attempted during the 16 Feb 1980 solar eclipse. Two Nike-Black Brant V sounding rockets carrying instrumented payloads were launched into the path of the advancing eclipse umbra from the San Marco satellite launch platform 3 miles off the east coast of Kenya.

  18. Assessing the measurement of aerosol single scattering albedo by Cavity Attenuated Phase-Shift Single Scattering Monitor (CAPS PMssa)

    NASA Astrophysics Data System (ADS)

    Perim de Faria, Julia; Bundke, Ulrich; Onasch, Timothy B.; Freedman, Andrew; Petzold, Andreas

    2016-04-01

    The necessity to quantify the direct impact of aerosol particles on climate forcing is already well known; assessing this impact requires continuous and systematic measurements of the aerosol optical properties. Two of the main parameters that need to be accurately measured are the aerosol optical depth and single scattering albedo (SSA, defined as the ratio of particulate scattering to extinction). The measurement of single scattering albedo commonly involves the measurement of two optical parameters, the scattering and the absorption coefficients. Although there are well established technologies to measure both of these parameters, the use of two separate instruments with different principles and uncertainties represents potential sources of significant errors and biases. Based on the recently developed cavity attenuated phase shift particle extinction monitor (CAPS PM_{ex) instrument, the CAPS PM_{ssa instrument combines the CAPS technology to measure particle extinction with an integrating sphere capable of simultaneously measuring the scattering coefficient of the same sample. The scattering channel is calibrated to the extinction channel, such that the accuracy of the single scattering albedo measurement is only a function of the accuracy of the extinction measurement and the nephelometer truncation losses. This gives the instrument an accurate and direct measurement of the single scattering albedo. In this study, we assess the measurements of both the extinction and scattering channels of the CAPS PM_{ssa through intercomparisons with Mie theory, as a fundamental comparison, and with proven technologies, such as integrating nephelometers and filter-based absorption monitors. For comparison, we use two nephelometers, a TSI 3563 and an Aurora 4000, and two measurements of the absorption coefficient, using a Particulate Soot Absorption Photometer (PSAP) and a Multi Angle Absorption Photometer (MAAP). We also assess the indirect absorption coefficient

  19. Purification and characterization of the glycoprotein hormone. cap alpha. -subunit-like material secreted by HeLa cells

    SciTech Connect

    Cox, G.S.; Rimerman, R.A.

    1988-08-23

    The protein secreted by HeLa cells that cross-reacts with antiserum developed against the ..cap alpha..-subunit of human chorionic gonadotropin (hCG) has been purified approximately 30,000-fold from concentrated culture medium by organic solvent fractionation followed by ion exchange, gel filtration, and lectin affinity chromatography. The final preparation had a specific activity (by RIA) of 6.8 x 10/sup 5/ ng of ..cap alpha../mg of protein and appeared homogeneous by electrophoresis on reducing/denaturing polyacrylamide gels (SDS-PAGE). Amino acid analysis indicated that HeLa-..cap alpha.. had a composition very similar to that of the urinary hCG ..cap alpha..-subunit. However, comparison of hCG-..cap alpha.. and HeLa-..cap alpha.. demonstrated that the tumor-associated subunit was not identical with its normal counterpart. The purified tumor protein had an apparent molecular weight greater than that of the urinary ..cap alpha..-subunit when analyzed by SDS-PAGE, and this difference was even greater when a partially purified preparation was examined by an immunoblot technique (Western). Isoelectric focusing of the HeLa and hCG subunits demonstrated that the tumor protein had a lower pI. Immunoprecipitation and electrophoresis of ..cap alpha..-subunit from HeLa cultures labeled with (/sup 3/H)fucose indicated that the tumor subunit was fucosylated, whereas analysis of hCG-..cap alpha.. hydrosylates by HPLC confirmed previous reports that the placental subunit does not contain fucose. The results indicate that, regardless of whether or not a single ..cap alpha..-subunit gene is being expressed in both normal and neoplastic tissues, posttranslational modifications lead to a highly altered subunit in the tumor. The differences observed may be useful in diagnosing neoplastic vs hyperplastic conditions and may lend insight into the mechanism of ectopic hormone production by tumors.

  20. Interaction between Ca/sup + +/-channel antagonists and. cap alpha. /sub 2/-adrenergic receptors in rabbit ileal cell membrane

    SciTech Connect

    Homeidan, F.R.; Wicks, J.; Cusolito, S.; El-Sabban, M.E.; Sharp, G.W.G.; Donowitz, M.

    1986-03-05

    An interaction between Ca/sup + +/-channel antagonists and the ..cap alpha../sub 2/-adrenergic receptor on active electrolyte transport was demonstrated in rabbit ileum. Clonidine, an ..cap alpha../sub 2/-agonist, stimulated NaCl absorption apparently by Ca/sup + +/-channel antagonism since it inhibited /sup 45/Ca/sup + +/ uptake across the basolateral membrane and decreased total ileal calcium content. This stimulation was inhibited by the Ca/sup + +/-channel antagonists dl- and l-verapamil and cadmium but not by nifedipine. The binding of /sup 3/H-yohimbine, a specific ..cap alpha../sub 2/-adrenergic antagonist, was studied on purified ileal cell membranes using a rapid filtration technique. dl-Verapamil and Cd/sup + +/ inhibited the specific binding of /sup 3/H-yohimbine over the same concentration range in which they affected transport. In contrast, nifedipine had no effect on binding, just as it had no effect on clonidine-stimulated NaCl absorption. These data demonstrate that there is an interaction between Ca/sup + +/-channels and ..cap alpha../sub 2/-adrenergic receptors in ileal basolateral membranes. Some Ca/sup + +/-channel antagonists alter ..cap alpha../sub 2/-adrenergic binding to the receptor and ..cap alpha../sub 2/-agonist binding leads to changes in Ca/sup + +/ entry. A close spatial relationship between the Ca/sup + +/-channel and the ..cap alpha../sub 2/-receptor could explain the data.

  1. Synthetic localization of a second toxin-binding region within residues. cap alpha. 182-198 of Torpedo acetylcholine receptor

    SciTech Connect

    Mulac-Jericevic, B.; Atassi, M.Z.

    1986-03-05

    A peptide, corresponding to the region 182-198 (peptide ..cap alpha..T182-198) of the ..cap alpha.. chain of Torpedo californica acetylcholine (AChR) was synthesized, purified and characterized. The binding activities of this peptide to ..cap alpha..-bungarotoxin and to cobratoxin were studied and compared to the activities of the previously reported synthetic peptide ..cap alpha..T125-147 of Torpedo ..cap alpha.. chain. Binding studies were performed by quantitative radiometric titrations by studying the binding of /sup 125/I-labelled peptides to toxin adsorbents and the binding of /sup 125/I labelled toxins to peptide adsorbents. The specificity of the binding was confirmed by appropriate inhibition experiments. The results showed unequivocally that the ..cap alpha.. chain of AChR contains a second toxin binding region which resides within, but may not comprise all of, the residues 182-198. The binding of toxins to one synthetic region is inhibited by the other. Thus, the ..cap alpha.. chain of AChR contains at least two toxin binding regions which may either be two faces of a larger single binding site or, alternatively, two binding sites that are spatially very close and thus the binding of one synthetic region to the toxin site could sterically obstruct the binding of the second synthetic region.

  2. Agonist-promoted desensitization and phosphorylation of. cap alpha. /sub 1/-adrenergic receptors coupled to stimulation of phosphatidylinositol metabolism

    SciTech Connect

    Leeb-Lundberg, L.M.F.; Cotecchia, S.; Caron, M.G.; Lefkowitz, R.J.

    1986-03-05

    In the DDT/sub 1/ MF-2 hamster vas deferens smooth muscle cell line the ..cap alpha../sub 1/-adrenergic receptor (..cap alpha../sub 1/-AR) agonist norepinephrine (NE) promotes rapid attenuation of ..cap alpha../sub 1/-AR-mediated phosphatidylinositol (PI) metabolism which is paralleled by rapid phosphorylation of the ..cap alpha../sub 1/-AR. Cells were labeled by incubation with /sup 32/P/sub i/. Coincubation with NE (100 ..mu..M) significantly increases the rate of /sup 32/P-labeling of both PI and phosphatidic acid. Pretreatment of cells with 100 ..mu..M NE (in the presence of 1 ..mu..M propranolol to prevent ..beta..-AR interactions) results in a drastic attenuation of the NE response on PI metabolism. ..cap alpha../sub 1/-AR from labeled cells can be solubilized and purified by affinity chromatography on Affigel-A55414 and wheat germ agglutinin agarose chromatography. SDS-PAGE of purified ..cap alpha../sub 1/-AR shows a NE-promoted increase in phosphorylation of the M/sub r/ 80K ligand binding peptide. Stoichiometry of phosphorylation increases from approx. 1 mol phosphate/mol ..cap alpha../sub 1/-AR in the basal condition to approx. 2.5 after NE treatment. Both desensitization and phosphorylation are rapid being maximal within 10-20 min of agonist exposure. These results together with previous findings that phorbol esters promote rapid ..cap alpha../sub 1/-AR uncoupling and phosphorylation suggest that receptor phosphorylation is an important mechanism of regulation of ..cap alpha../sub 1/-AR receptor responsiveness.

  3. Time Delay in Neutron-Alpha Resonant Scattering

    SciTech Connect

    Hoop, Bernard; Hale, Gerald M.

    2011-10-24

    Time delay analysis of neutron-alpha resonant scattering cross sections supports characterization of the lowest 3/2{sup +} level in {sup 5}He as fundamentally an n-{alpha} resonance on the second Riemann energy sheet of both n-{alpha} and deuteron-{sup 3}H channels, with an associated shadow pole on a different unphysical sheet that, through its associated zero on the physical sheet, contributes to the large {sup 4}He(n,d){sup 3}H cross section.

  4. Stable yeast transformants that secrete functional. cap alpha. -amylase encoded by cloned mouse pancreatic cDNA

    SciTech Connect

    Filho, S.A.; Galembeck, E.V.; Faria, J.B.; Frascino, A.C.S.

    1986-04-01

    Mouse pancreatic ..cap alpha..-amylase complementary DNA was inserted into a yeast shuttle vector after the Saccharomyces cerevisiae MF..cap alpha..1 promoter and secretion signals coding sequences. When transformed with the recombinant plasmid, S. cerevisiae cells were able to synthesize and secrete functional ..cap alpha..-amylase, efficiently hydrolyzing starch present in the culture medium. Stable amylolytic cells were obtained from different yeast strains. This work represents a significant step towards producing yeast that can convert starchy materials directly to ethanol.

  5. Separation of Cf, Es, and Fm by eluative chromatography using ammonium. cap alpha. -hydroxyisobutyrate

    SciTech Connect

    Mikheev, N.B.; Kamenskaya, A.N.; Auerman, L.N.; Kulyukhin, S.A.; Rumer, I.A.; Novichenko, V.L.

    1987-11-01

    The method of separation of californium, einsteinium, fermium, and certain lanthanides, based on the use of ammonium ..cap alpha..-hydroxyisobutyrate as the eluent, has been improved. The use of a 0.10-0.14 M solution of this reagent and columns (9 x 0.5 cm) filled with the resin Aminex SB with particle size 20-25 ..mu.., permitted the production of about 0.5 ..mu..g of einsteinium-253 from irradiated californium-252 with coefficient of purification of einsteinium from californium in two cycles of adsorption and elution of approx. 10/sup 10/. The coefficient of separation of californium and einsteinium is equal to 1.6 and that of einsteinium and fermium 1.9. The behavior of certain lanthanides in the separation of californium, einsteinium, and fermium using a 0.010 M solution of ammonium ..cap alpha..-hydroxyisobutyrate is discussed.

  6. Stable expression of transfected Torpedo acetylcholine receptor. cap alpha. subunits in mouse fibroblast L cells

    SciTech Connect

    Claudio, T.

    1987-08-01

    Torpedo californica electric organ cDNA libraries were constructed in lambdagt10 and lambdagt11. Four acetylcholine receptor (AcChoR) subunit cDNA clones were isolated and shown to contain the entire coding region for each of the subunits. When in vitro synthesized AcChoR mRNA was microinjected into Xenopus laevis oocytes, functional cell surface AcChoRs were expressed. A very simple and fast /sup 22/Na-uptake experiment was performed on batches of microinjected oocytes to identify oocytes that were expressing large quantities of functional cell surface AcChoRs for use in single-channel recordings. In addition to the transient expression system, DNA-mediated contransformation is described, which is a method for stably introducing AcChoR cDNAs into the chromosomes of tissue culture cells. Because the AcChoR is composed of four different subunits, it is necessary to integrate four cDNAs into the chromosomes of the same cell before stable expression of a completely functional receptor complex can be established. The authors show that 80% of the cells that integrated the selectable marker gene into their chromosomes also integrated all four AcChoR cDNAs. When Torpedo ..cap alpha..-subunit cDNA inserted into an appropriate expression vector was introduced into cells by transfection, ..cap alpha..-subunit protein was synthesized that migrated on NaDodSO/sub 4//polyacrylamide gels with the same molecular mass as native Torpedo ..cap alpha.. subunits and expressed antigenic determinants similar to those of native Torpedo ..cap alpha.. subunits.

  7. Radar scattering from venus at large angles of incidence and the question of polar ice caps.

    PubMed

    Jurgens, R F

    1968-12-20

    Spectrum analysis of radar waves backscattered from an anulus near the limb of Venus shows that a uniform scattering model applies over regions extending from the equator to within approximately 15 degrees of the poles. These observations indicate that large polar ice caps extending to latitudes as low as 60 degrees are very unlikely.

  8. TFTR 60 GHz alpha particle collective Thomson Scattering diagnostic

    SciTech Connect

    Machuzak, J.S.; Woskov, P.P.; Gilmore, J.; Bretz, N.L.; Park, H.K.; Aamodt, R.E.; Cheung, P.Y.; Russell, D.A.; Bindslev, H.

    1995-03-01

    A 60 GHz gyrotron collective Thomson Scattering alpha particle diagnostic has been implemented for the D-T period on TFM. Gyrotron power of 0.1-1 kW in pulses of up to 1 second can be launched in X-mode. Efficient corrugated waveguides are used with antennaes and vacuum windows of the TFTR Microwave Scattering system. A multichannel synchronous detector receiver system and spectrum analyzer acquire the scattered signals. A 200 Megasample/sec digitizer is used to resolve fine structure in the frequency spectrum. By scattering nearly perpendicular to the magnetic field, this experiment will take advantage of an enhancement of the scattered signal which results from the interaction of the alpha particles with plasma resonances in the lower hybrid frequency range. Significant enhancements are expected, which will make these measurements possible with gyrotron power less than 1 kW, while maintaining an acceptable signal to noise ratio. We hope to extract alpha particle density and velocity distribution functions from the data. The D and T fuel densities and temperatures may also be obtainable by measurement of the respective ion cyclotron harmonic frequencies.

  9. Stimulation of the synthesis of 15-hydroxyeicosatetraenoic acid (15-HETE) and 6-keto-prostaglandin F/sub 1. cap alpha. / (6-keto-PGF/sub 1. cap alpha. /) by cultured human umbilical veins

    SciTech Connect

    Ibe, B.O.; Johnson, A.R.; Falck, J.R.; Campbell, W.B.

    1986-03-05

    These studies were designed to investigate the synthesis of 6-keto-PGF/sub 1..cap alpha../ and 15-HETE in cultured human endothelial cells. The identification of the 15-HETE in these cells was made by UV absorption and gas chromatography/mass spectrometry. Specific radioimmunoassays were developed to quantify the synthesized 6-keto-PGF/sub 1..cap alpha../ and 15-HETE. The release of 15-HETE and 6-keto-PGF/sub 1..cap alpha../ was stimulated by arachidonic acid, histamine or the calcium ionophore A23187. The release of 15-HETE paralleled the release of 6-keto-PGF/sub 1..cap alpha../ and was both concentration-related and time-dependent. Aspirin, ibuprofen and indomethacin inhibited both the formation of 6-keto-PGF/sub 1..cap alpha../ and 15-HETE in similar concentrations. These data indicate that agents which stimulate PGI/sub 2/ synthesis also stimulate the synthesis of 15-HETE. Also, they implicate the cyclooxygenase pathway in the synthesis of 6-keto PGF/sub 1..cap alpha../ and 15-HETE in human endothelial cells.

  10. Estrogen receptor binding radiopharmaceuticals: II. Tissue distribution of 17. cap alpha. -methylestradiol in normal and tumor-bearing rats

    SciTech Connect

    Feenstra, A.; Vaalburg, W.; Nolten, G.M.J.; Reiffers, S.; Talma, A.G.; Wiegman, T.; van der Molen, H.D.; Woldring, M.G.

    1983-06-01

    Tritiated 17..cap alpha..-methylestradiol was synthesized to investigate the potential of the carbon-11-labeled analog as an estrogen-receptor-binding radiopharmaceutical. In vitro, 17..cap alpha..-methylestradiol is bound with high affinity to the cytoplasmic estrogen receptor from rabbit uterus (K/sub d/ = 1.96 x 10/sup -10/M), and it sediments as an 8S hormone-receptor complex in sucrose gradients. The compound shows specific uptake in the uterus of the adult rat, within 1 h after injection. In female rats bearing DMBA-induced tumors, specific uterine and tumor uptakes were observed, although at 30 min the tumor uptake was only 23 to 30% of the uptake in the uterus. Tritiated 17..cap alpha..-methylestradiol with a specific activity of 6 Ci/mmole showed a similar tissue distribution. Our results indicate that a 17 ..cap alpha..-methylestradiol is promising as an estrogen-receptor-binding radiopharmaceutical.

  11. Limited proteolysis of human leukocyte interferon-. cap alpha. 2 and localization of the monoclonal antibody-binding antigenic determinant

    SciTech Connect

    Kostrov, S.V.; Chernovskaya, T.V.; Khodova, O.M.; Borukhov, S.I.; Ryzhavskaya, A.S.; Izotova, L.S.; Strongin, A.Ya.

    1986-05-20

    Large peptide fragments of human leukocyte interferon-..cap alpha..2 (INF-..cap alpha..2) were produced by limited proteolysis with trypsin, pepsin, thermolysin, and Bacillus amyloliquefaciens serine proteinase, and the ability of the fragments to react with murine monoclonal antibodies NK2, directed toward INF-..cap alpha..2, was studied by the immunoblotting technique. The region of the sequence 110-149 is the most sensitive to proteinase attack and evidently is exposed on the surface of the INF-..cap alpha..2 molecule. The INF-..cap alpha..2 fragments 1-139, 1-147, and 1-149 react with antibodies, whereas the fragments 1-109 and 1-112 do not bind NK2 antibodies. A comparison of the primary structure of the families of human leukocyte and murine leukocyte INF in the region of the sequence 110-139 and an analysis of the ability of human INF differing in amino acid sequence to interact with NK2 antibodies suggested that the antigenic determinant that binds monoclonal antibodies NK2 is the sequence Glu/sub 114/-Asp/sub 115/-Ser/sub 116/-He/sub 117/ of the INF-..cap alpha..2 molecule.

  12. Control of. cap alpha. -amylase mRNA accumulation by gibberellic acid and calcium in barley aleurone layers

    SciTech Connect

    Deikman, J.; Jones, R.L.

    1985-01-01

    Pulse-labeling of barley (Hordeum vulgare L. cv Himalaya) aleurone layers incubated for 13 hours in 2.5 micromolar gibberellic acid (GA/sub 3/) with or without 5 millimolar CaCl/sub 2/ shows that ..cap alpha..-amylase isozymes 3 and 4 are not synthesized in vivo in the absence of Ca/sup 2 +/. No difference was observed in ..cap alpha..-amylase mRNA levels between layers incubated for 12 hours in 2.5 micromolar GA/sub 3/ with 5 millimolar CaCl/sub 2/ and layers incubated in GA/sub 3/ alone. RNA isolated from layers incubated for 12 hours in GA/sub 3/ with and without CA/sup 2 +/. A cDNA clone for ..cap alpha..-amylase was isolated and used to measure ..cap alpha..-amylase mRNA levels in aleurone layers incubated in the presence and absence of Ca/sup 2 +/ was translated in vitro and was found to produce the same complement of translation products regardless of the presence of Ca/sup 2 +/ in the incubation medium. Immunoprecipitation of translation products showed that the RNA for ..cap alpha..-amylase synthesized in Ca/sup 2 +/-deprived aleurone layers was translatable. Ca/sup 2 +/ is required for the synthesis of ..cap alpha..-amylase isozymes 3 and 4 at a step after mRNA accumulation and processing.

  13. Capillary electrophoretic study of thiolated alpha-cyclodextrin-capped gold nanoparticles with tetraalkylammonium ions.

    PubMed

    Paau, Man Chin; Lo, Chung Keung; Yang, Xiupei; Choi, Martin M F

    2009-11-27

    Capillary zone electrophoresis (CZE) has been employed to characterize nanometer-sized thiolated alpha-cyclodextrin-capped gold nanoparticles (alpha-CD-S-AuNPs). The addition of tetrabutylammonium (Bu(4)N(+)) ions to the run buffer greatly narrows the migration peak of alpha-CD-S-AuNP. The optimal run buffer was determined to be 10mM Bu(4)N(+) in 30 mM phosphate buffer at pH 12 and an applied voltage of 15 kV. The effect of various tetraalkylammonium ions on the peak width and electrophoretic mobility (mu(e)) of alpha-CD-S-AuNP was studied in detail. Bu(4)N(+) ions assist in inter-linking the alpha-CD-S-AuNPs and narrowing the migration peak in CZE. This observation can be explained by the fact that each Bu(4)N(+) ion can simultaneously interact with several hydrophobic cavities of the surface-attached alpha-CDs on AuNPs. The TEM images show that alpha-CD-S-AuNPs with Bu(4)N(+) are linked together but in the absence of Bu(4)N(+), they are more dispersed. The migration mechanism in CZE is based on the formation of inclusion complexes between Bu(4)N(+) and alpha-CD-S-AuNPs which induces changes in the charge-to-size ratio of alpha-CD-S-AuNPs and mu(e). An inverse linear relationship (r(2)>0.998) exists between the mu(e) and size of alpha-CD-S-AuNPs in the core range 1.4-4.1 nm. The CZE analyses are rapid with migration time less than 4 min. A few nanoliters of each of the alpha-CD-S-AuNP samples were injected hydrodynamically at 0.5 psi for 5s. Our work confirms that CZE is an efficient tool for characterizing the sizes of alpha-CD-S-AuNPs using Bu(4)N(+) ions. PMID:19853853

  14. Pressor effect for ethanol and absence of its. cap alpha. -blocking activity in the SHR

    SciTech Connect

    Abdel-Rahman, A.R.A.; Iams, S.G.; Wooles, V.R.

    1986-03-01

    In a previous study the authors have suggested ethanol (ETOH) has an ..cap alpha..-blocking activity in anesthetized Sprague Dawley (SD) rats. The present investigation shows that ETOH (1 g/Kg, i.v.) has a pressor and tachycardic effect in SHR, SD and Wistar Kyoto (WKY) rats. However, quantitative differences existed between ..delta.. MAP, but not ..delta.. HR, among the 3 strains; the biggest rise occurred in the SHR and the least in SD. It is not yet clear whether the significantly higher MAP in the SHR contributes to the significantly larger ..delta.. MAP in response to ETOH. Nonetheless, MAP was similar in WKY and SD in spite of a larger ..delta.. MAP after ETOH in the former. Furthermore, both SD and WKY rats showed a significant and parallel rightward shift of the phenylephrine (PE) pressor response curve after ETOH (more in SD than WKY) suggesting an ..cap alpha..-blocking activity for ethanol and confirming their previous findings in SD rats. This suggestion was further supported by the absence of any shift in the angiotensin II (AII) dose-response curves. On the other hand, neither PE nor AII pressor responsiveness was influenced by ETOH in the SHR suggesting an absence of ..cap alpha..-blocking activity for ETOH in this strain. Finally, no change occurred in the baroreflex control of HR in SHR as compared to an impairment of this function in WKY and SD rats. This may relate at least in part, to the already depressed baroreflex function in the SHR.

  15. Radiation-induced cationic polymerization of limonene oxide,. cap alpha. -pinene oxide, and. beta. -pinene oxide

    SciTech Connect

    Aikins, J.A.; Williams, F.

    1984-01-01

    After suitable drying, the subject monomers in the form of neat liquids undergo radiation-induced polymerization with no apparent side reactions and high conversions to precipitatable polymers of low molecular weight. A cationic mechanism is evidenced by the strongly retarding effect of tri-n-propylamine on the polymerization rate. At 25/sup 0/C, limonene oxide gives the highest polymerization rates, an average conversion of 36% per Mrad being obtained in comparison with values of 5.7 and 7.3% per Mrad for the ..cap alpha..-pinene and ..beta..-pinene oxides, respectively. Similarly, the average anti DP/sub n/ decreases from 11.8 for the limonene oxide polymer to 5.6 and 4.0 for the ..cap alpha..-pinene oxide and ..beta..-pinene oxide polymers, respectively. A high frequency of chain transfer to monomer is indicated in each case by the fact that the kinetic chain lengths are estimated to be on the order of a hundred times larger than the anti DP/sub n/ values. Structural characterization of the limonene oxide polymer by /sup 1/H and /sup 13/C NMR spectroscopy provides conclusive evidence that the polymerization proceeds by the opening of the epoxide ring to yield a 1,2-trans polyether. Similar NMR studies on the polymers formed from the ..cap alpha..-pinene and ..beta..-pinene oxides show that in the polymerization of these monomers, the opening of the epoxide ring is generally accompanied by the concomitant ring opening of the cyclobutane ring structure to yield a gem-dimethyl group in the main chain. The detection of isopropenyl end groups in the pinene oxide polymers is also consistent with this mode of propagation being followed by chain (proton) transfer to monomer.

  16. Producing a compound Nucleus via Inelastic Scattering: The 90Zr(alpha,alpha')90Zr* Case

    SciTech Connect

    Escher, J E; Dietrich, F S

    2008-05-23

    In a Surrogate reaction a compound nucleus is produced via a direct reaction (pickup, stripping, or inelastic scattering). For a proper application of the Surrogate approach it is necessary to predict the resulting angular momentum and parity distribution in the compound nucleus. A model for determining these distributions is developed for the case of inelastic alpha scattering off a spherical nucleus. The focus is on obtaining a first, simple description of the direct-reaction process that produces the compound nucleus and on providing the basis for a more complete treatment of the problem. The approximations employed in the present description are discussed and the extensions required for a more rigorous treatment of the problem are outlined. To illustrate the formalism, an application to {sup 90}Zr({alpha},{alpha}{prime}){sup 90}Zr* is presented.

  17. Quasi-relativistic SCF X. cap alpha. study of octahedral 5f/sup 1/ complexes

    SciTech Connect

    Thornton, G.; Roesch, N.; Edelstein, N.

    1980-05-01

    Quasi-relativistic SCF X..cap alpha.. calculations have been carried out for the octahedral 5f/sup 1/ complexes Pa/sup IV/X/sub 6//sup 2 -/, U/sup V/X/sub 6//sup -/(X = F, Cl, Br, I), and Np/sup VI/F/sub 6/. The 5f ..-->.. 5f excitation energies calculated by using the transition-state method agree well with the available absorption spectra. Ionic effects appear to dominate the trends observed in the f-orbital ligand field splitting.

  18. Structure of products of the condensation of. cap alpha. ,. beta. -unsaturated aldehydes with dimedone

    SciTech Connect

    Yurchenko, O.I.; Pushkareva, K.S.; Zheldubovskaya, G.A.; Komarov, N.V. Berkova, G.A.

    1987-10-10

    ..cap alpha..,..beta..-Acetylenic aldehydes and cinnamaldehyde in reaction with dimedone give the corresponding unsaturated bis(dimedonyl)methanes. In the case of acrolein and crotonaldehyde intramolecular cyclization occurs with the participation of hydroxyl of the dimedone fragment and the double bond with the formation of pyran systems. The PMR spectra were determined on Tesla BS-487C (80 MHz) and Tesla BS-467C (60 MHz) spectrometers in chloroform-d, pyridine-d/sub 5/, and trifluoroacetic acid solutions. Internal standards HMDS and methylene chloride.

  19. Involvement of prostaglandins F/sub 2. cap alpha. / and E/sub 1/ with rabbit endometrium

    SciTech Connect

    Orlicky, D.J.

    1985-01-01

    Several growth factors and hormones are thought to play a role in the growth control of endometrial cells. The authors have shown that prostaglandin F/sub 2..-->../ (PGF/sub 2..cap alpha../) is a growth factor for primary cultures of rabbit endometrium cultured in chemically-defined serum-free medium and that prostaglandin E/sub 1/ (PGE/sub 1/) antagonizes the PGF/sub 2..-->../ induction of growth. Both (/sup 3/H)PGF/sub 2..cap alpha../ and (/sup 3/H)PGE/sub 1/ bind in a time and temperature dependent, dissociable, saturable and specific manner. The binding of (/sup 3/H)PGF/sub 2..cap alpha../ and (/sup 3/H)PGE/sub 1/ can be both down and up regulated and is enzyme sensitive. PGE /sub 1/ stimulates intracellular cAMP synthesis and accumulation in a time and concentration dependent manner. PGF/sub 2..cap alpha../ probably exerts its effects through an amiloride-sensitive intermediate. Both PGF/sub 2..cap alpha../ and PGE/sub 1/ are constitutively synthesized by these primary cultures, and they have shown this synthesis to be both drug and hormone sensitive. They hypothesize that it is the ratio, rather than the absolute quantities, of PGF/sub 2..cap alpha../ and PGE/sub 1/ which is of more importance in the regulation of endometrial cell growth. Furthermore, they believe this regulation of endometrial growth plays a role in control of proliferation during the decidual response and that a derangement in the ratio of these prostaglandins may lead to either infertility or hyperplasia. The ability of these cultures to synthesize prostaglandins in a hormonally regulatable manner may be of importance in the study of dysmenorrhea and uterine cramping as caused by the myometrial contracting prostaglandin, PGF/sub 2..cap alpha../.

  20. Stimulation of bovine heart pyruvate dehydrogenase kinase by. cap alpha. -ketoisovalerate in the presence of thiamin pyrophosphate

    SciTech Connect

    Robertson, J.G.; Barron, L.L.; Olson, M.S.

    1987-05-01

    Purified bovine heart pyruvate dehydrogenase complex was used to study pyruvate dehydrogenase kinase (PDH kinase) regulation. Previously, they showed that KCl and NH4Cl stimulate PDH kinase, and that thiamin pyrophosphate over the range of 1-80 ..mu..M completely blocks PDH kinase stimulation by 20 mM KCl, whereas thiamin pyrophosphate has very little inhibitory effect in the absence of KCl. Under inhibitory conditions, 100 ..mu..M thiamin pyrophosphate and 20 mM KCl, addition of 1 mM ..cap alpha..-ketoisovalerate stimulated PDH kinase activity 1.5-fold. Addition of 1 mM ..cap alpha..-ketoisovalerate had a similar stimulatory effect in the presence of 1 mM NH4Cl and 100 ..mu..M thiamin pyrophosphate. Half-maximal stimulation occurred at about 200 ..mu..M ..cap alpha..-ketoisovalerate in both cases. Inhibition by thiamin pyrophosphate was uncompetitive, and the effect of ..cap alpha..-ketoisovalerate on thiamin pyrophosphate inhibition was to shift both Vm and Km toward control values without changing the slope of the reciprocal plot. After incubation of pyruvate dehydrogenase complex with ..cap alpha..-ketoisovalerate and gel filtration on Sephadex G-25 to remove ..cap alpha..-ketoisovalerate, PDH kinase activity remained stimulated relative to controls incubated with only buffer. In bovine heart mitochondria solubilized in 0.2% Triton X-100 and incubated with (..gamma..-/sup 32/P)ATP, ..cap alpha..-ketoisovalerate stimulated PDH phosphorylation in the presence of thiamin pyrophosphate, as detected by SDS-PAGE and autoradiography. The results indicate that acylation of pyruvate dehydrogenase complex results in PDH kinase stimulation, but only in the presence of monovalent cation and thiamin pyrophosphate. Furthermore, the results also suggest that this effect may be relevant under more in vivo conditions.

  1. Physiological characterization of Saccharomyces cerevisiae mutants supersensitive to G1 arrest by a factor and. cap alpha. factor pheromones

    SciTech Connect

    Chan, R.K.; Otte, C.A.

    1982-01-01

    Saccharomyces cerevisiae MATa cells carrying mutations in either sst1 or sst2 are supersensitive to the G1 arrest induced by ..cap alpha.. factor pheromone. When sst1 mutants were mixed with normal SST/sup +/ cells, the entire population recovered together from ..cap alpha.. factor arrest, suggesting that SST/sup +/ cells helped sst1 mutants to recover. Complementation tests and linkage analysis showed that sst1 and bar1, a mutation which eliminates the ability of MATa cells to act as a ''barrier'' to the diffusion of ..cap alpha.. factor, were lesions in the same genes. These findings suggest that sst1 mutants are defective in recovery from ..cap alpha.. factor arrest because they are unable to degrade the pheromone. In contrast, recovery of sst2 mutants was not potentiated by the presence of SST/sup +/ cells in mixing experiments. When either normal MATa cells or mutant cells carrying defects in sst1 or sst2 were exposed to ..cap alpha.. factor for 1 h and then washed free of the pheromone, the sst2 cells subsequently remained arrested in the absence of ..cap alpha.. factor for a much longer time than SST/sup +/ or sst1 cells. These observations suggest that the defect in sst2 mutants is intrinsic to the cell and is involved in the mechanism of ..cap alpha.. factor action at some step after the initial interaction of the pheromone with the cell. The presence of an sst2 mutation appears to cause a growth debility, since repeated serial subculture of haploid sst2-1 strains led to the accumulation of faster-growing revertants that were pheromone resistant and were mating defective (''sterile'').

  2. Reaction of HO/sub 2//O/sub 2//sup -/ with. cap alpha. -tocopherol in ethanolic solutions

    SciTech Connect

    Arudi, R.L.; Sutherland, M.W.; Bielski, B.H.J.

    1982-01-01

    The HO/sub 2/ perhydroxyl radical reacts with ..cap alpha..-tocopherol in 85% ethanol containing some H/sub 2/SO/sub 4/, EDTA, and O/sub 2/. The resulting transient has a spectral maximum near 390 ..mu... The final product is mostly ..cap alpha..-tocopherylquinone. Best reproducibility for reaction of O/sub 2//sup -/ with ..cap alpha..-tocopherol was obtained in a deoxygenated reaction mixture of 26 +- 3 ..mu..M O/sub 2//sup -/, 0.0565M ..cap alpha..-tocopherol, 5..mu..M EDTA, and 0.005 M KOH in 85% EtOH; the upper limit for the reaction was 6.0 +- 3.0 M/sup -1/ s/sup -1/, indicating that for all practical purposes O/sub 2//sup -/ does not react at all with ..cap alpha..-tocopherol. Preliminary experiments with Trolox, a vitamin E model compound, indicates that it too reacts with HO/sub 2/ but not with O/sub 2//sup -/. Membrane-bound tocopherols in vivo may fulfil a dual antioxidant role. (DLC)

  3. Sensitive radioimmunoassay of. cap alpha. human atrial natriuretic polypeptide using monoclonal antibody recognizing human form ring structure

    SciTech Connect

    Naomi, S.; Umeda, T.; Iwaoka, T.; Miura, F.; Ohno, M.; Sasaki, M.; Oishi, S.; Sato, T.; Takatsu, K.

    1988-01-01

    A monoclonal antibody (C351) against ..cap alpha.. human atrial natriuretic polypeptide (..cap alpha..hANP) recognizing human form ring structure was established and applied to a radioimmunoassay of plasma ..cap alpha..hANP. The minimum detectable amount in terms of 10 % radioligand displacement relative to zero dose were 0.28 fmol/tube, corresponding to 0.7 fmol/ml in plasma after extraction using Sep-Pak C18 cartridges. When the mean plasma levels at recumbent position in fasted morning were compared in 10 young (<30 years) and 10 elderly (greater than or equal to50 years) healthy subjects taking normal sodium diet, it was slightly higher in the latter. After i.v. infusion of hypertonic saline at a rate of 0.24 ml/kg/min for 20 min in 6 normal subjects (26 to 35 years), it was increased from 4.1 +/- 0.4 to 5.9 +/- 0.7 fmol/ml (p<0.01). In 6 patients with essential hypertension (34 to 57 years), it was elevated with high salt intake. From these results, the radioimmunoassay of plasma IR-..cap alpha..hANP using MAb C351 seems to be quite suitable to detect rather small changes at low plasma concentrations and to investigate a physiological importance of ..cap alpha..hANP in man.

  4. Removal of. cap alpha. -tocopherol from blood and its comparison with other lipids

    SciTech Connect

    Gardner, H.K.; Vang, M.J.; Mavis, R.D.

    1986-01-01

    The blood decay curve of ..cap alpha..-tocopherol in rats was compared with those of the two major blood lipids by labeling rat serum in vitro with /sup 3/H-..cap alpha..-tocopherol (AT), /sup 3/H-cholesterol (CHO) or /sup 3/H-trioleoylglycerol (TO) and injecting it into the bloodstream. For the three lipids, loss from blood was biphasic. The half time of the faster decay was 2-4 minutes. The slower curve decayed with half times of 42, 289 and 990 minutes for TO, AT and CHO, respectively. This intermediate rate of AT removal is consistent with its accompanying both of the major blood lipids as they are removed by their respective mechanisms or with a process specific for AT. To investigate the role of liver in the faster curve, animals were hepatectomized. TO and CHO loss remained biphasic after liver removal. However, AT loss became monophasic, with a loss rate intermediate between the non-hepatectomized fast and slow decays. This demonstrates a central role for liver in the metabolism of blood-borne AT and a mode of removal distinct from the other two lipids.

  5. Interaction of nicotinic receptor affinity reagents with central nervous system. cap alpha. -bungarotoxin-binding entities

    SciTech Connect

    Lukas, R.J.; Bennett, E.L.

    1980-01-01

    Membrane-bound ..cap alpha..-bungarotoxin-binding entities derived from rat brain are found to interact specifically with the affinity reagents maleimidobenzyltrimethylammonium (MBTA) and bromoacetylcholine (BAC), originally designed to label nicotinic acetylcholine receptors from electroplax and skeletal muscle. Following treatment of membranes with dithiothreitol, all specific toxin binding sites are irreversibly blocked by reaction with MBTA or BAC. Affinity reagent labeling of dithiothreitol-reduced membranes is prevented (toxin binding sites are not blocked) by prior alkylaction with N-ethylmaleimide, by prior oxidation with dithiobis(2-nitrobenzoic acid), or by incubation with neurotoxin. Reversibly associating cholinergic agonists and antagonists retard the rate of affinity reagent interaction with toxin receptors. The apparent rates of affinity reagent alkylation of toxin receptors, and the influences of other sulfhydryl/disulfide reagents on affinity labeling are comparable to those observed for reaction with nicotinic acetylcholine receptors in the periphery. The results provide further evidence that central nervous system ..cap alpha..-bungarotoxin receptors share a remarkable number of biochemical properties with nicotinic receptors from the periphery.

  6. ON THE ORIGINS OF THE DIFFUSE H{alpha} EMISSION: IONIZED GAS OR DUST-SCATTERED H{alpha} HALOS?

    SciTech Connect

    Seon, Kwang-Il; Witt, Adolf N.

    2012-10-20

    It is known that the diffuse H{alpha} emission outside of bright H II regions not only are very extended, but also can occur in distinct patches or filaments far from H II regions, and the line ratios of [S II] {lambda}6716/H{alpha} and [N II] {lambda}6583/H{alpha} observed far from bright H II regions are generally higher than those in the H II regions. These observations have been regarded as evidence against the dust-scattering origin of the diffuse H{alpha} emission (including other optical lines), and the effect of dust scattering has been neglected in studies on the diffuse H{alpha} emission. In this paper, we reexamine the arguments against dust scattering and find that the dust-scattering origin of the diffuse H{alpha} emission cannot be ruled out. As opposed to the previous contention, the expected dust-scattered H{alpha} halos surrounding H II regions are, in fact, in good agreement with the observed H{alpha} morphology. We calculate an extensive set of photoionization models by varying elemental abundances, ionizing stellar types, and clumpiness of the interstellar medium (ISM) and find that the observed line ratios of [S II]/H{alpha}, [N II]/H{alpha}, and He I {lambda}5876/H{alpha} in the diffuse ISM accord well with the dust-scattered halos around H II regions, which are photoionized by late O- and/or early B-type stars. We also demonstrate that the H{alpha} absorption feature in the underlying continuum from the dust-scattered starlight ({sup d}iffuse galactic light{sup )} and unresolved stars is able to substantially increase the [S II]/H{alpha} and [N II]/H{alpha} line ratios in the diffuse ISM.

  7. H/sub. cap alpha. / photon yield in fuelling of tokamaks

    SciTech Connect

    McNeill, D.H.

    1988-08-01

    The number of H/sub ..cap alpha../ photons emitted per entering particle is examined for three types of fueling in tokamaks: wall and limiter efflux, gas puff, and solid pellet injection. These sources correspond to greater involvement of heavy particles in the breakup of entering molecules and to an increasing degree of thermodynamic equilibrium in the radiating zone. The effect of wall absorption and charge exchange on the photon yield in normal tokamak discharges is examined with a molecular influx model. The emission from a perturbing gas puff is discussed qualitatively as an extension to this model. The photon yield from injected pellets corresponds to a limit of extremely high neutral influx and is estimated with a simple hydrodynamical model and measured pellet cloud parameters. 23 refs., 4 figs., 1 tab.

  8. dl-. cap alpha. -tocopheryl succinate enhances the effect of. gamma. -irradiation on neuroblastoma cells in culture

    SciTech Connect

    Sarri, A.; Prasad, K.N.

    1984-01-01

    The effect of dl-..cap alpha..-tocopheryl (vitamin E) succinate in modifying the radiation response of mouse neuroblastoma (NBP/sub 2/) and mouse fibroblast (L-cells) cells in culture was studied on the criterion of growth inhibition (due to cell death and inhibition of cell division). Results show that vitamin E succinate markedly enhanced the effect of /sub 60/CO-..gamma..-irradiation on NB cells, but it did not significantly modify the effect of irradiation on mouse fibroblasts. Sodium succinate plus ethanol (0.25% final concentration) did not modify the radiation response of NB cells or fibroblasts. Butylated hydroxyanisole, a lipid soluble antioxidant, also enhanced the effect of irradiation on NB cells, indicating that the effect of vitamin E in modifying the radiation response may be mediated, in part, by antioxidation mechanisms.

  9. Chemical and physical consequences of. cap alpha. and. beta. /sup -/ decay in the solid state

    SciTech Connect

    Young, J.P.; Haire, R.G.; Peterson, J.R.; Ensor, D.D.

    1984-01-01

    Interesting chemical and structural phenomena can occur when radioactive materials are stored in the solid state. Extensive studies have been made of both the chemical and physical status of progeny species that result from the ..cap alpha.. or ..beta.. /sup -/ day of actinide ions in several different compounds. The samples have been both initially pure actinide compounds - halides, oxides, etc. and actinides incorporated into other non-radioactive host materials, for example lanthanide halides. In general, the oxidation state of the actinide progeny is controlled by the oxidation state of its parent (a result of heredity). The structure of the progeny compound seems to be controlled by its host (a result of environment). These conclusions are drawn from solid state absorption spectral studies, and where possible, from x-ray diffraction studies of multi-microgram sized samples. 13 references, 4 figures, 4 tables.

  10. BMY 20064, a potent calcium channel blocker with. cap alpha. /sub 1/-adrenoceptor antagonist properties

    SciTech Connect

    Stanton, H.C.; Rosenberger, L.B.; Hanson, R.C.; Fleming, J.S.; Poindexter, G.

    1986-03-05

    BMY 20064 ((3-(4-(2-methoxyphenyl)-1-piperazinyl)propyl)-methyl 1,4-dihydro-2-6-dimethyl-4-(3-nitrophenyl)-3-5-pyridinedicarboxylate) is a new Ca/sup +2/ channel blocking agent equivalent in activity to nifedipine in the isolated K/sup +/ depolarized rat aorta. It is also an ..cap alpha../sub 1/ selective antagonist (0.17x prazosin) in a radioligand binding assay. BMY 20064 (10-/sup 7/M) was more effective than nifedipine (10/sup -7/M) in antagonizing net increases in /sup 45/Ca/sup +2/ uptake induced in isolated rabbit aortic strips by K/sup +/ (80 mM), norepinephrine (10/sup -5/M), methoxamine (10/sup -5/M) or a combination of K/sup +/ and adrenergic agonist. In ganglion-blocked, anesthetized rats, BMY 20064 (3, 10 and 15 mg/kg, p.o.) induced shifts in the dose-effect curve of phenylephrine of 2.8 +/- 1.2, 12.8 +/- 5.1 and 30.5 +/- 7.8, respectively. BMY 20064 (0.3 - 10 mg/kg, p.o.) induced dose-related decreases in arterial blood pressure of SH rats and normotensive rats of 6-8 hours duration. BMY 20064, (i.v.), prevented the loss in ATP which occurs when the excised rat heart is incubated for 15 minutes at 37/sup 0/C under global ischemic conditions. BMY 20064 was also much more active than nifedipine, prazosin or combinations of nifedipine-prazosin in preventing ADP or collagen-induced aggregation of human platelets in vitro. The actions of BMY 20064 may not be due entirely to its Ca/sup +2/ or ..cap alpha../sub 1/ receptor blocking actions.

  11. Pivotal and distinct role for Plasmodium actin capping protein alpha during blood infection of the malaria parasite.

    PubMed

    Ganter, Markus; Rizopoulos, Zaira; Schüler, Herwig; Matuschewski, Kai

    2015-04-01

    Accurate regulation of microfilament dynamics is central to cell growth, motility and response to environmental stimuli. Stabilizing and depolymerizing proteins control the steady-state levels of filamentous (F-) actin. Capping protein (CP) binds to free barbed ends, thereby arresting microfilament growth and restraining elongation to remaining free barbed ends. In all CPs characterized to date, alpha and beta subunits form the active heterodimer. Here, we show in a eukaryotic parasitic cell that the two CP subunits can be functionally separated. Unlike the beta subunit, the CP alpha subunit of the apicomplexan parasite Plasmodium is refractory to targeted gene deletion during blood infection in the mammalian host. Combinatorial complementation of Plasmodium berghei CP genes with the orthologs from Plasmodium falciparum verified distinct activities of CP alpha and CP alpha/beta during parasite life cycle progression. Recombinant Plasmodium CP alpha could be produced in Escherichia coli in the absence of the beta subunit and the protein displayed F-actin capping activity. Thus, the functional separation of two CP subunits in a parasitic eukaryotic cell and the F-actin capping activity of CP alpha expand the repertoire of microfilament regulatory mechanisms assigned to CPs.

  12. Complete amino acid sequence of human plasma Zn-. cap alpha. /sub 2/-glycoprotein and its homology to histocompatibility antigens

    SciTech Connect

    Araki, T.; Gejyo, F.; Takagaki, K.; Haupt, H.; Schwick, H.G.; Buergi, W.; Marti, T.; Schaller, J.; Rickli, E.; Brossmer, R.

    1988-02-01

    In the present study the complete amino acid sequence of human plasma Zn-..cap alpha../sub 2/-glycoprotein was determined. This protein whose biological function is unknown consists of a single polypeptide chain of 276 amino acid residues including 8 tryptophan residues and has a pyroglutamyl residue at the amino terminus. The location of the two disulfide bonds in the polypeptide chain was also established. The three glycans, whose structure was elucidated with the aid of 500 MHz /sup 1/H NMR spectroscopy, were sialylated N-biantennas. The molecular weight calculated from the polypeptide and carbohydrate structure is 38,478, which is close to the reported value of approx. = 41,000 based on physicochemical measurements. The predicted secondary structure appeared to comprised of 23% ..cap alpha..-helix, 27% ..beta..-sheet, and 22% ..beta..-turns. The three N-glycans were found to be located in ..beta..-turn regions. An unexpected finding was made by computer analysis of the sequence data; this revealed that Zn-..cap alpha../sub 2/-glycoprotein is closely related to antigens of the major histocompatibility complex in amino acid sequence and in domain structure. There was an unusually high degree of sequence homology with the ..cap alpha.. chains of class I histocompatibility antigens. Moreover, this plasma protein was shown to be a member of the immunoglobulin gene superfamily. Zn-..cap alpha../sub 2/-glycoprotein appears to be truncated secretory major histocompatibility complex-related molecule, and it may have a role in the expression of the immune response.

  13. Isolation and genetic analysis of Saccharomyces cerevisiae mutants supersensitive to G1 arrest by a factor and. cap alpha. factor pheromones

    SciTech Connect

    Chan, R.K.; Otte, C.A.

    1982-01-01

    Eight independently isolated mutants which are supersensitive (Sst/sup -/) to the G1 arrest induced by the tridecapeptide pheromone ..cap alpha.. factor were identified by screening mutagenized Saccharomyces cerevisiae MATa cells on solid medium for increased growth inhibition by ..cap alpha.. factor. These mutants carries lesions in two complementation groups, sst1 and sst2. Mutations at the sst1 locus were mating type specific: MATa sst1 cells were supersensitive to ..cap alpha.. factor, but MAT..cap alpha.. sst1 cells were not supersensitive to a factor. In contrast, mutations at the sst2 locus conferred supersensitivity to the pheromones of the opposite mating type on both MATa and MAT..cap alpha.. cells. Even in the absence of added ..cap alpha.. pheromone, about 10% of the cells in exponentially growing cultures of MATa strains carrying any of three different alleles of sst2 (including the ochre mutation sst2-4) had the aberrant morphology (''shmoo'' shape) that normally develops only after MATa cells are exposed to ..cap alpha.. factor. This ''self-shmooing'' phenotype was genetically linked to the sst2 mutations, although the leakiest allele isolated (sst2-3) did not display this characteristic. Normal MATa/MAT..cap alpha.. diploids do not respond to pheromones; diploids homozygous for an sst2 mutation (MATa/MAT..cap alpha.. sst2-1/sst2-1) were still insensitive to ..cap alpha.. factor. The sst1 gene was mapped to within 6.9 centimorgans of his6 on chromosome IX. The sst2 gene was unlinked to sst1, was not centromere linked, and was shown to be neither linked nor centromere distal to MAT on the right arm of chromosome III.

  14. Method and means for helium/hydrogen ratio measurement by alpha scattering

    NASA Technical Reports Server (NTRS)

    Whitehead, A. B.; Tombrello, T. A. (Inventor)

    1980-01-01

    An apparatus for determining helium to hydrogen ratios in a gaseous sample is presented. The sample is bombarded with alpha particles created by a self contained radioactive source and scattering products falling within a predetermined forward scattering angular range impact a detector assembly. Two detectors are mounted in tandem, the first completely blocking the second with respect to incident scattering products. Alpha particle/hydrogen or alpha particle/helium collisions are identified by whether scattering product impacts occur simultaneously in both detectors or only in the first detector. Relative magnitudes of the two pulses can be used to further discriminate against other effects such as noise and cosmic ray events.

  15. Amino acids of the Torpedo marmorata acetylcholine receptor. cap alpha. subunit labeled by a photoaffinity ligand for the acetylcholine binding site

    SciTech Connect

    Dennis, M.; Giraudat, J.; Kotzyba-Hibert, F.; Goeldner, M.; Hirth, C.; Chang, J.Y.; Lazure, C.; Chretien, M.; Changeux, J.P.

    1988-04-05

    The acetylcholine-binding sites on the native, membrane-bound acetylcholine receptor from Torpedo marmorata were covalently labeled with the photoaffinity reagent (/sup 3/H)-p-(dimethylamino)-benzenediazonium fluoroborate (DDF) in the presence of phencyclidine by employing an energy-transfer photolysis procedure. The ..cap alpha..-chains isolated from receptor-rich membranes photolabeled in the absence or presence of carbamoylcholine were cleaved with CNBr and the radiolabeled fragments purified by high-performance liquid chromatography. Amino acid and/or sequence analysis demonstrated that the ..cap alpha..-chain residues Trp-149, Tyr-190, Cys-192, and Cys-193 and an unidentified residue(s) in the segment ..cap alpha.. 31-105 were all labeled by the photoaffinity reagent in an agonist-protectable manner. The labeled amino acids are located within three distinct regions of the large amino-terminal hydrophilic domain of the ..cap alpha..-subunit primary structure and plausibly lie in proximity to one another at the level of the acetylcholine-binding sites in the native receptor. These findings are in accord with models proposed for the transmembrane topology of the ..cap alpha..-chain that assign the amino-terminal segment ..cap alpha.. 1-210 to the synaptic cleft. Furthermore, the results suggest that the four identified (/sup 3/H)DDF-labeled resides, which are conserved in muscle and neuronal ..cap alpha..-chains but not in the other subunits, may be directly involved in agonist binding.

  16. Toxin a from Clostridium difficile binds to rabbit erythrocyte glycolipids with therminal Gal. cap alpha. 1-3Gal. beta. 1-4GlcNaC sequences

    SciTech Connect

    Clark, G.F.; Krivan, H.; Wilkins, T.; Smith, D.F.

    1987-05-01

    Toxin A is one of two clostridial toxins implicated as the causative agent of pseudomembranous colitis in patients undergoing postoperative antibiotic therapy. Evidence that the carbohydrate binding determinant for this toxin is a glycoconjugate(s) with non-reducing Gal..cap alpha..1-3Gal..beta..1-4GlcNAc has recently been reported. Specific agglutination of rabbit erythrocytes by Toxin A is inhibited by bovine thyroglobulin and prevented by pretreatment of cells with ..cap alpha..-galactosidase. Total lipid extracts from rabbit erythrocytes were subjected to thin layer chromatography and the chromatogram overlaid with purified /sup 125/I-labeled Toxin A. Two major and several minor toxin-binding glycolipids were detected following autoradiography. The major toxin-binding glycolipids were identified as pentasaccharide- and decasaccharide-ceramides expressing terminal Gal..cap alpha..1-3Gal..beta..1-4GlcNAc sequences. Treatment of the toxin-binding glycolipids with ..cap alpha..-galactosidase abolished binding. Forsmann glycolipid, globoside, Gal..cap alpha..1-4 Gal..beta..1-4Glc-cer, and Gal..cap alpha..1-3Gal..beta..1-4Glc-cer did not bind the toxin. These observations are consistent with the proposed carbohydrate specificity of the toxin for the non-reducing terminal sequence, Gal..cap alpha..1-3Gal..beta..1-4GlcNAc.

  17. Removal of. cap alpha. -tocopherol from blood and its comparison with other lipids: studies of inhibition

    SciTech Connect

    Gardner, H.K.; Mavis, R.D.

    1986-05-01

    To investigate the mechanism of ..cap alpha..-tocopherol (AT) uptake into tissues, loss of /sup 3/H-AT from blood was characterized and compared with the losses of two major blood lipids: /sup 3/H-cholesterol (CHO) and /sup 3/H-trioleoylglycerol (TO). Male Long-Evans rats (200-325 gm) were injected with serum labelled with one lipid, and bled from the tail from 1-240 min. In one group heparin (HEP), an inhibitor of lipoprotein lipase which mediates uptake of TO into tissues, was intravenously injected prior to serum and following corn oil gavage. The control group was only gavaged (GAV). A third group was injected with labelled serum which had been incubated with 1,2-cyclohexanedione (CHD), a reagent which modifies the receptors responsible for removal of CHO-rich low density lipoproteins from blood. Labelled serum incubated only with borate buffer (BO) was injected into the fourth group. HEP slowed TO loss from 2-220 min, but left CHO loss unchanged. AT loss was slowed by HEP from 100 min on. That AT responded to HEP but over a time span different from that of TO suggests that AT may be removed by a mechanism distinct from that of TO but sensitive to HEP. CHD slowed CHO loss from 40-240 min while TO and AT loss were uninhibited. This argues against a mechanism of removal common to both AT and CHO.

  18. cap alpha. -Naphthylisothiocyanate (ANIT) stimulates the release of superoxide by rat neutrophils in vitro

    SciTech Connect

    Roth, R.A.; Hewett, J.

    1986-03-01

    ..cap alpha..-Naphthylisothiocyanate (ANIT) is an hepatotoxicant that produces cholestasis and hyperbilirubinemia in rats. Its mechanism of action is unknown. The observation that polymorphonuclear leukocytes (PMNs) accumulate in the bile ductular region of the liver following ANIT administration prompted us to examine the ability of ANIT to stimulate these cells. PMNs elicited from rat peritoneum were treated with ANIT in vitro to test for the release of superoxide anion (O/sub 2//sup -/). ANIT stimulated O/sub 2//sup -/ release from PMNs in a concentration-dependent manner. Maximal O/sub 2//sup -/ release was achieved by an ANIT concentration of 110 ..mu.. M. O/sub 2//sup -/ release was rapid after the first few minutes of ANIT addition and ceased entirely between 10 and 15 minutes. An increase in the extracellular activity of lactate dehydrogenase also occurred after a 5-10 minute lag phase following ANIT addition. PMNs exposed to ANIT also failed to exclude trypan blue dye, either in the presence or in the absence of superoxide dismutase and catalase, suggesting a direct, oxygen radical-independent, cytotoxic effect of ANIT on PMNs. Release of the lysosomal enzyme, ..beta..-glucuronidase, also occurred within 5 min following exposure of PMNs to ANIT. These results indicate that ANIT stimulates the release of cytotoxic agents from rat PMNs in vitro and suggests that the direct stimulation of PMNs in vivo may contribute to ANIT-induced hepatotoxicity in rats.

  19. Novel /sup 18/O kinetic isotope effect in an. cap alpha. -chymotrypsin catalyzed transesterification

    SciTech Connect

    Wang, C.L.A.; Trout, C.M.; Calvo, K.C.; Klapper, M.H.; Wong, L.K.

    1980-01-30

    Reactions were started by injecting the nitrophenyl ester into a stoppered vial immersed in a constant-temperature bath (4/sup 0/C) containing a mixture of /sup 16/O plus /sup 18/O-ethanol, ..cap alpha..-chymotrypsin, and buffer. As the reaction proceeded, samples were withdrawn and injected into a gas chromatograph connected to a quadrupole mass spectrometer controlled by a data acquisition and processing system. The intensities from individual ions were displayed as a function of time to yield chromatographic peaks. Relative /sup 18/O enrichments were computed from the ratios of the peak areas, and the apparent KIE was then calculated from the ratio of enrichments in alcohol and ester. The values of the plateau KIE were less than or equal to 0.90 for all experiments. The apparent first-order rate constant can also be calculated from the magnitude of the initial burst and the slope of the zero-order absorbence increase. This apparent rate constant varies linearly with the ethanol concentration permitting calculation of the second-order rate associated with the formation of the ethyl ester product. 2 figures, 1 table.

  20. Characterization of D-enzyme (4-. cap alpha. -glucanotransferase) in Arabidopsis leaf

    SciTech Connect

    Lin, T.P.; Preiss, J.

    1988-01-01

    Two major forms of D-enzyme (4-..cap alpha..-glucanotransferase, EC 2.4.1.25) were successfully separated from most of the amylase activity using FPLC-Mono Q column chromatography. Transfer of a maltosyl group was observed upon the incubation of D-enzyme with maltotriose and D-(U-/sup 14/C)glucose. About 4.5% of the radioactivity was transferred to maltotriose in 2 hours. End product analysis showed the accumulation of glucose and maltopentaose from maltotriose within the first 10 minutes of the reaction. Several other maltodextrins were also observed with longer incubation times, although maltose was never produced. A quantitative measurement of maltodextrin production from the reaction of (/sup 14/C)maltotriose with D-enzyme showed that the quantity of maltotriose decreased from 100% to 31% after 3 hours incubation, while glucose, maltotetraose, maltopentaose, maltohexaose, maltoheptaose, maltooctaose, and higher maltodextrins increased in amount. Glucose is the major product throughout the course of the reaction of D-enzyme with maltotriose. Maltotriose, in addition to glucose, are the major products in the reaction of D-enzyme with maltodextrins with a chain length greater than maltotriose. This study confirms the existence of a transglycosylase that disproportionates amaltotriose and higher maltodextrins by transferring maltosyl or maltodextrinyl groups between maltodextrins resulting in the production of glucose and different maltodextrins, but not maltose.

  1. Radiation-induced cationic polymerization of limonene oxide,. cap alpha. -pinene oxide, and. beta. -pinene oxide

    SciTech Connect

    Aikins, J.A.; Williams, F.

    1985-01-01

    After suitable drying, the subject monomers in the form of neat liquids undergo radiation-induced polymerization with no apparent side reactions and high conversions to precipitatable polymers of low molecular weights. A high frequency of chain (proton) transfer to monomer is indicated by the fact that the kinetic chain lengths are estimated to be several hundred times larger than the range of DP/sub n/ values (12-4). Structural characterization of the limonene oxide polymer by /sup 1/H and /sup 13/C NMR spectroscopy provides conclusive evidence that the polymerization proceeds by the opening of the epoxide ring to yield a 1,2-trans polyether. Similar NMR studies on the polymers formed from the ..cap alpha..-pinene and ..beta..-pinene oxides show that the opening of the epoxide ring for these monomers is generally accompanied by the concomitant ring opening of the cyclobutane ring structure to yield a gem-di-methyl group in the main chain.

  2. Rapid postexposure decay of. cap alpha. /sub 2u/-globulin and hyaline droplets in the kidneys of gasoline-treated male rats

    SciTech Connect

    Garg, B.D.; Olson, M.J.; Demyan, W.F.; Roy, A.K.

    1988-01-01

    Renal ..cap alpha../sub 2u/-globulin content increased to 210% of control within 18 h of a single oral dose of gasoline (2.0 ml/kg) in male rats; maximal levels (320% of control) were attained following gasoline administration for 3 d. Increases in renal ..cap alpha../sub 2u/-globulin caused by gasoline were accompanied by concurrent proliferation of hyaline droplets. However, within 3 d of terminating gasoline administration renal ..cap alpha../sub2u/-globulin content decreased to the same level as that in unexposed rats, although renal hyaline droplet number returned to pretreatment levels somewhat more slowly. The conjoint effect of postexposure recovery and estradiol (an inhibitor of hepatic ..cap alpha../sub 2u/-globulin synthesis) administration was also determined in male rats. On postexposure of 3, 6, and 9, estradiol treatment (1 mg/kg, sc, 4 d, starting on d 9 of gasoline treatment) decreased renal ..cap alpha../sub 2u/-globulin content to 75%, 59%, and 48%, respectively, of that in rats allowed to recover from gasoline with no hormone treatment. Hepatic ..cap alpha../sub 2u/-globulin content in estradiol-treated rats was decreased by 74%, 97%, and 96% at the same intervals. Estradiol treatment during recovery from gasoline also appeared to increase the removal of accumulated hyaline droplets from the renal cortex. Thus, accumulation of ..cap alpha../sub 2u/-globulin-containing hyaline droplets after subacute exposure of male rats to gasoline is rapidly reversible, dependent on continuous exposure to gasoline and maintenance of the normal rate of hepatic ..cap alpha../sub 2u/-globulin synthesis. These results emphasize the dynamic state of renal cortical hyaline droplets and suggest strongly that gasoline hydrocarbons cause hyaline droplet accumulation by prolonging the half-time degradation of ..cap alpha../sub 2u/-globulin.

  3. Dendrimer-Capped Gold Nanoparticles for Highly Reliable and Robust Surface Enhanced Raman Scattering.

    PubMed

    Kim, Kwanghyun; Lee, Jeongyeop; Jo, Gyeongcheon; Shin, Seungmin; Kim, Jin-Baek; Jang, Ji-Hyun

    2016-08-10

    Dendrimer-stabilized gold nanoparticles (Au-Den) were prepared by a facile solution based method for a highly reliable and robust surface enhanced Raman scattering (SERS) substrate. Au-Den was selectively attached on the surface of reduced graphene oxide (rGO) by noncovalent interactions between the Au capping dendrimer and the graphene surface. Au-Den/rGO exhibits the outstandingly stable and highly magnified Raman signal with an enhancement factor (EF) of 3.9 × 10(7) that enables detection of R6G dyes with concentration as low as 10 nM, retaining 95% of the Raman signal intensity after 1 year. The remarkable stability and enhancement originated not only from a simple combination of the electromagnetic and chemical mechanism of SERS but also from intensified packing density of stable Au-Den on the graphene substrate due to the firm binding between the dendrimer capped metal nanoparticles and the graphene substrate. This method is not limited to the gold nanoparticles and G4 dendrimer used herein, but also can be applied to other dendrimers and metal nanoparticles, which makes the material platform suggested here superior to other SERS substrates. PMID:27403733

  4. Kinetics of ozonation. 4. Reactions of ozone with. cap alpha. -tocopherol and oleate and linoleate esters in carbon tetrachloride and in aqueous micellar solvents

    SciTech Connect

    Giamalva, D.H.; Church, D.F.; Pryor, W.A.

    1986-10-15

    Vitamin E (..cap alpha..-tocopherol; ..cap alpha..-T) is known to protect animals against the deleterious effects of ozone in polluted air; one such effect is the ozone-initiated autooxidation of polyunsaturated fatty acids (PUFA) that occur in membranes. In order to assess the possibility of a direct reaction of ozone with ..cap alpha..-T competing with the very fast ozone-PUFA reaction, we have measured the rates of reaction of ozone with ..cap alpha..-T, oleic acid, and linoleic acid. I CCl/sub 4/ as solvent, ..cap alpha..-T reacts with ozone with a rate constant of about 5500 M/sup -1/ s/sup -1/; methyl oleate and methyl linoleate react 2 orders of magnitude faster. In aqueous micellar solutions the rate constants for ..cap alpha..-T and the fatty acids are more similar. The k for the ozone/..cap alpha..-T reaction is about 1 x 10/sup 6/ M/sup -1/ s/sup -1/ at pH 7, but decreases as the solution becomes more acidic; the k's for oleic acid and linoleic acid are ca. 1 x 10/sup 6/ M/sup -1/ s/sup -1/ and exhibit no significant pH dependence. Since the ratio of fatty acids to ..cap alpha..-T in membranes is typically at least 100-1000 to 1, we conclude that the direct reaction of ozone with ..cap alpha..-T is unlikely. Thus, the protection that vitamin E provides to animals breathing ozone-containing air must result from vitamin E acting as a free radical scavenger. We have also detected the ..cap alpha..-tocopheroxyl radical as an intermediate from the reaction of ozone with ..cap alpha..-T both in CCl/sub 4/ and aqueous micelles using electron spin resonance spectroscopy. The authors suggest that the observation of this intermediate is consistent with an initial electron transfer from ..cap alpha..-T to ozone.

  5. High spatial resolution observations of Orion bright bar: CS (J = 1-0) and H51. cap alpha. emission

    SciTech Connect

    Omodaka, T.; Hayashi, M.; Hasegawa, T.

    1984-07-15

    High-resolution strip maps of CS (J = 1-0) and H51..cap alpha.. line emission across the Orion bright bar are presented. The intensity of CS emission is weaker in the H II region with a rapid increase at the optical bar, while the H51 ..cap alpha.. line was detected only on the side of the H II region. The variation of the CS intensity can be reproduced by a beam-convolved step function with the position of the step coincident with the ionization front. The molecular cloud associated with the bright bar is redshifted relative to the ambient molecular cloud by about 2 km s/sup -1/. This may suggest the dynamical interactions between the molecular cloud and the H II region excited by the Trapezium stars.

  6. {sup 110,116}Cd({alpha},{alpha}){sup 110,116}Cd elastic scattering and systematic investigation of elastic {alpha} scattering cross sections along the Z=48 isotopic and N=62 isotonic chains

    SciTech Connect

    Kiss, G. G.; Fueloep, Zs.; Gyuerky, Gy.; Elekes, Z.; Farkas, J.; Somorjai, E.; Mohr, P.; Yalcin, C.; Galaviz, D.; Gueray, R. T.; Oezkan, N.; Goerres, J.

    2011-06-15

    The elastic scattering cross sections for the reactions {sup 110,116}Cd({alpha},{alpha}){sup 110,116}Cd at energies above and below the Coulomb barrier are presented to provide a sensitive test for the {alpha}-nucleus optical potential parameter sets. Additional constraints for the optical potential are taken from the analysis of elastic scattering excitation functions at backward angles which are available in literature. Moreover, the variation of the elastic {alpha} scattering cross sections along the Z=48 isotopic and N=62 isotonic chain is investigated by the study of the ratios of the {sup 106,110,116}Cd({alpha},{alpha}){sup 106,110,116}Cd scattering cross sections at E{sub cm{approx_equal}}15.6and18.8 MeV and the ratio of the {sup 110}Cd({alpha},{alpha}){sup 110}Cd and {sup 112}Sn({alpha},{alpha}){sup 112}Sn reaction cross sections at E{sub cm{approx_equal}}18.8 MeV, respectively. These ratios are sensitive probes for the {alpha}-nucleus optical potential parametrizations. The potentials under study are a basic prerequisite for the prediction of {alpha}-induced reaction cross sections (e.g., for the calculation of stellar reaction rates in the astrophysical p or {gamma} process).

  7. Transport of. cap alpha. -aminoisobutyric acid by Streptococcus pyogenes and its derived L-form

    SciTech Connect

    Reizer, J.; Panos, C.

    1982-01-01

    We studied the uptake of ..cap alpha..-aminoisobutyric acid (AIB) in Streptococcus pyogenes and its physiologically isotonic L-form. S. pyogenes cells starved for glucose or treated with carbonyl cyanide-m-chlorophenyl hydrazone accumulated limited amounts of AIB. A high apparent K/sub m/ value characterized the glucose-independent transport of AIB. The rate and extent of AIB accumulation significantly increased in the presence of glucose. Two saturable transport components with distinct apparent K/sub m/values characterized glycolysis-coupled transport of AIB. A biphasic Lineweaver-Burk plot was also obtained for L-alanine transport by glycolyzing S. pyogenes cells. AIB seems to share a common transport system(s) with glycine, L- and D-anine, L-serine, and L-valine. This was shown by the competitive exchange efflux of accumulated AIB. About 30% of the AIB uptake was not inhibited by a saturating amount of L-valine, indicating the existence of more than one system for AIB transport, p-Chloromercuribenzoate markedly inhibited the accumulation of AIB by both glycolyzing and glucose-starved cells. In contrast, carbonyl cyanide-m-chlorophenyl hydrazone affected only metabolism-dependent uptake of AIB, which was also sensitive to dinitrophenol, N-ethylmaleimide, iodoacetate, fluoride (NaF), arsenate, and N,N'-dicyclohexylcarbodiimide. These results are interpreted according to the chemiosmotic theory of Mitchell, whereby a proton motive force constitutes the driving force for AIB accumulation. AIB was not accumulated by the L-form. However, a temporary accumulation of AIB by a counterflow mechanism and a saturable system with a low apparent affinity were demonstrated for AIB transport by this organism. We suggest that a deficiency in the coupling of energy to AIB transport is responsible for the apparent lack of active AIB accumulation by the L-form.

  8. Production of inositol trisphosphates upon. cap alpha. -adrenergic stimulation in BC3H-1 muscle cells

    SciTech Connect

    Ambler, S.K.; Thompson, B.; Brown, J.H.; Taylor, P.

    1986-05-01

    Activation of ..cap alpha../sub 1/-adrenergic receptors in BC3H-1 muscle cells rapidly mobilizes intracellular and results in a paradoxically slower accumulation of inositol trisphosphate. A possible explanation for this discrepancy may be provided by the recent findings of Irvine et al. of additional Ins P3 isomers besides the Ca/sup + +/-mobilizing isomer, Ins 1,4,5-P3. They have eluted and separated the inositol phosphates of BC3H-1 cells with an NH/sub 4//sup +/ x HCO/sub 2//sup -//H/sub 3/PO/sub 4/ gradient on a Whatman Partisil 10SAX column using Hewlett-Packard HPLC. Commercial (/sup 3/H)Ins 1,4,5-P3 and (/sup 3/H)inositol phosphates from carbachol-stimulated parotid glands were used as standards. Little or no Ins 1,3,4-P3 could be detected in control or phenylephrine-treated BC3H-1 cells. Ins 1,4,5-P3 followed the pattern of agonist stimulation observed previously. As a positive control, Ins P3 isomers were also measured in 1321N1 astrocytoma cells. Muscarinic stimulation of 1321N1 cells results in both the rapid accumulation of Ins P3 and Ca/sup + +/ mobilization. There is no detectable basal Ins 1,3,4-P3, but carbachol stimulates a rapid production of this compound in 1321N1 cells. Agonist activation also results in a rapid increase in Ins 1,4,5-P3 above basal values. These studies indicate that Ins 1,3,4-P3 does not contribute to the InsP3 signal in BC3H-1 cells and multiple mechanisms may exist for the coupling of receptors to PI turnover.

  9. Clearance of. cap alpha. -aminoisobutyric acid during in-situ perfusion of the guinea pig placenta

    SciTech Connect

    Kelman, B.J.; Sikov, M.R.

    1983-05-01

    Extensive investigation of the transport of ..cap alpha..-aminoisobutyric acid (AIB; a nonmetabolized amino acid) has shown that AIB is actively transported from mother to fetus across the hemochorial placenta of the guinea pig. As a step towards clarifying the relative rolls of active and passive movements of amino acids across the placenta, it would be useful to obtain concurrent measurements of transplacental movements of a substance which crosses the placenta rapidly by simple diffusion (water) and of a substance which is actively transported across the placenta (AIB). In our study, placentas from guinea pigs between 59 and 61 days of gestation were perfused in situ through cannulated umbilical vessels with the maternal circulation left intact. Tritiated water and /sup 14/C-AIB were injected into a maternal jugular vein and maternal blood samples were obtained at 1 to 10 minute intervals; perfusate samples were collected sequentially after one pass through the placenta. Clearance of /sup 14/C-AIB from mother to fetus (AIB/sub MF/) and AIB concentrations in placental tissue, maternal plasma, and perfusate were consistent in magnitude with data obtained by other invetigators who have clearly shown an active transport of AIB in the placenta. On the other hand, in this study AIB/sub MF/ ranged from approximately 50% to 96% of the clearance of /sup 3/H-labeled water from mother to fetus (T/sub MF/) and that changes in AIB/sub MF/ correlated closely with changes in T/sub MF/ in all perfusions. Thus, it appears that AIB/sub MF/ closely paralleled T/sub MF/ and these data suggest that a relatively large component of AIB/sub MF/ is of passive origin in the in situ placenta.

  10. N- and C-capping preferences for all 20 amino acids in alpha-helical peptides.

    PubMed Central

    Doig, A. J.; Baldwin, R. L.

    1995-01-01

    We have determined the N- and C-capping preferences of all 20 amino acids by substituting residue X in the peptides NH2-XAKAAAAKAAAAKAAGY-CONH2 and in Ac-YGAAKAAAAKAAAAKAX-CO2H. Helix contents were measured by CD spectroscopy to obtain rank orders of capping preferences. The data were further analyzed by our modified Lifson-Roig helix-coil theory, which includes capping parameters (n and c), to find free energies of capping (-RT ln n and -RT ln c), relative to Ala. Results were obtained for charged and uncharged termini and for different charged states of titratable side chains. N-cap preferences varied from Asn (best) to Gln (worst). We find, as expected, that amino acids that can accept hydrogen bonds from otherwise free backbone NH groups, such as Asn, Asp, Ser, Thr, and Cys generally have the highest N-cap preference. Gly and acetyl group are favored, as are negative charges in side chains and at the N-terminus. Our N-cap preference scale agrees well with preferences in proteins. In contrast, we find little variation when changing the identity of the C-cap residue. We find no preference for Gly at the C-cap in contrast to the situation in proteins. Both N-cap and C-cap results for Tyr and Trp are inaccurate because their aromatic groups affect the CD spectrum. The data presented here are of value in rationalizing mutations at capping sites in proteins and in predicting the helix contents of peptides. PMID:7670375

  11. Effect of thermal treatment on the catalytic properties of crystalline. cap alpha. -Ti(HPO/sub 4/)/sub 2/ x H/sub 2/O

    SciTech Connect

    Titov, V.P.; Bel'skaya, R.I.; Berezovik, G.K.; Berezutskii, S.S.; Yakubovskaya, S.V.

    1987-10-10

    The authors studied the effect of the thermal treatment ..cap alpha..-TiP on its catalytic properties in the dehydration of cyclohexanol. The results obtained were compared with the acid properties of the ..cap alpha..-TiP samples. The studies showed that the catalytic activity of ..cap alpha..-TiP in the dehydration of cyclohexanol depends on the temperature of the prior thermal treatment and passes through a maximum at 480/sup 0/C. The catalytic activity of these samples is related to the amount of strong acid sites. The regeneration of POH groups is possible in the case of a high treatment temperature for ..cap alpha..-TiP. This regeneration occurs during the catalytic reaction.

  12. {alpha} resonance structure in {sup 11}B studied via resonant scattering of {sup 7}Li+{alpha}

    SciTech Connect

    Yamaguchi, H.; Hashimoto, T.; Hayakawa, S.; Binh, D. N.; Kahl, D.; Kubono, S.; Wakabayashi, Y.; Kawabata, T.; Teranishi, T.

    2011-03-15

    A new measurement of {alpha} resonant scattering on {sup 7}Li was performed over the excitation energy of 10.2-13.0 MeV in {sup 11}B at the low-energy RI beam facility CNS Radioactive Ion Beam separator (CRIB) of the Center for Nuclear Study (CNS), University of Tokyo. The excitation function of {sup 7}Li+{alpha} at 180 deg. in the center-of-mass system was successfully measured for the first time with the inverse kinematics method, providing important information on the {alpha} cluster structure in {sup 11}B and the reaction rate of {sup 7}Li({alpha},{gamma}), which is relevant to the {sup 11}B production in the {nu} process in core-collapse supernovae. The excitation function of the {sup 7}Li({alpha},p) reaction cross section for 11.7-13.1 MeV was also measured.

  13. Alpha particle condensation in {sup 12}C and nuclear rainbow scattering

    SciTech Connect

    Ohkubo, S.; Hirabayashi, Y.

    2008-05-12

    It is shown that the large radius of the Hoyle state of {sup 12}C with a dilute density distribution in an {alpha} particle condensate can be clearly seen in the shift of the rainbow angle (therefore the Airy minimum) to a larger angle in {alpha}+{sup 12}C rainbow scattering at the high energy region and prerainbow oscillations in {sup 3}He+{sup 12}C scattering at the lower energy region.

  14. Microscopic cluster model of {alpha}+n, {alpha}+p, {alpha}+ {sup 3}He, and {alpha}+{alpha} elastic scattering from a realistic effective nuclear interaction

    SciTech Connect

    Dohet-Eraly, J.; Baye, D.

    2011-07-15

    An effective nucleon-nucleon interaction adapted to cluster-model calculations of collisions is derived from the realistic Argonne potential AV18 with the unitary correlation operator method. The unitary correlation is determined from the {alpha}+{alpha} elastic phase shifts calculated in a cluster approach by the generator coordinate method coupled with the microscopic R-matrix method. With this interaction, the elastic phase shifts for the {alpha}+n, {alpha}+p, and {alpha}+{sup 3}He collisions are calculated within the same model. Without further adjustment, a good agreement with experimental data is obtained with a small model space.

  15. Dihydropyridine-sensitive calcium channels in cardiac and skeletal muscle membranes: studies with antibodies against the. cap alpha. subunits

    SciTech Connect

    Takahashi, M.; Catterall, W.A.

    1987-08-25

    Polyclonal antibodies (PAC-2) against the purified skeletal muscle calcium channel were prepared and shown to be directed against ..cap alpha.. subunits of this protein by immunoblotting and immunoprecipitation. These polypeptides have an apparent molecular weight of 162,000 without reduction of disulfide bonds. Under conditions where the functional properties of the purified skeletal muscle calcium channel are retained, ..beta.. subunits (M/sub r/ 50,000) and lambda subunits (M/sub r/ 33,000) are coprecipitated, demonstrating specific noncovalent association of these three polypeptides in the purified skeletal muscle channel. PAC-2 immunoprecipitated cardiac calcium channels labeled with (/sup 3/H)isopropyl 4-(2,1,3-benzoxadiazol-4-yl)-1,4-dihydro-2,6-dimethyl-5-(methoxycarbonyl)pyridine-3-carboxylate ((/sup 3/H)PN200-110) at a 3-fold higher concentration than skeletal muscle channels. Preincubation with cardiac calcium channels blocked only 49% of the immunoreactivity of PAC-2 toward skeletal muscle channels, indicating that these two proteins have both homologous and distinct epitopes. The immunoreactive component of the cardiac calcium channel was identified by immunoprecipitation and polyacrylamide gel electrophoresis as a polypeptide with an apparent molecular weight of 170,000 before reduction of disulfide bonds and 141,000 after reduction, in close analogy with the properties of the ..cap alpha../sub 2/ subunits of the skeletal muscle channel. The calcium channels were radiolabeled with /sup 32/P and /sup 125/I. It is concluded that these two calcium channels have a homologous, but distinct, ..cap alpha.. subunit as a major polypeptide component.

  16. Bose-Einstein condensation of {alpha} particles and Airy structure in nuclear rainbow scattering

    SciTech Connect

    Ohkubo, S.; Hirabayashi, Y.

    2004-10-01

    It is shown that the dilute density distribution of {alpha} particles in nuclei can be observed in the Airy structure in nuclear rainbow scattering. We have analyzed {alpha}+{sup 12}C rainbow scattering to the 0{sub 2}{sup +} (7.65 MeV) state of {sup 12}C in a coupled-channel method with the precise wave functions for {sup 12}C. It is found that the enhanced Airy oscillations in the experimental angular distributions for the 0{sub 2}{sup +} state is caused by the dilute density distribution of this state in agreement for the idea of Bose-Einstein condensation of the three alpha particles.

  17. Nuclear clusters studied with alpha resonant scatterings using RI beams at CRIB

    NASA Astrophysics Data System (ADS)

    Yamaguchi, H.; Kahl, D.; Nakao, T.; Wakabayashi, Y.; Hashimoto, T.; Hayakawa, S.; Kawabata, T.; Teranishi, T.; Kwon, Y. K.; Binh, D. N.; Khiem, L. H.; Duy, N. N.; Kubono, S.; Suhara, T.; Kanada-En'yo, Y.; Moon, J. Y.; Kim, A.; Iwasa, N.; Lee, P. S.; Chae, K. Y.; Cha, S. M.; Gwak, M. S.; Kim, D. H.; Milman, E.

    2014-12-01

    Alpha resonant scattering is a simple and promising method to study α-cluster structure in nuclei. It has several good features which enable us to perform measurements with short-lived and relatively low-intense RI beams. Several measurements on alpha resonant scattering have been carried out at CRIB (CNS Radioactive Ion Beam separator), which is a low-energy RI beam separator at Center for Nuclear Study (CNS) of the University of Tokyo. Recent α resonant scattering studies at CRIB, using 7Li, 7Be and 10Be beams with a helium gas target, are discussed.

  18. Human interleukin 1. beta. (IL-1. beta. ), a more powerful inducer of bone demineralization than interleukin 1. cap alpha. IL-1. cap alpha. ), parathyroid hormone (PTH) or prostaglandin E/sub 2/ (PGE/sub 2/) in vitro

    SciTech Connect

    Chin, R.C.; Hodges, Y.C.; Allison, A.C.

    1986-03-01

    Effects of human IL-1..cap alpha.. and IL-1..beta.., prepared by recombinant DNA technology on cultures of rat fetal long bones, prelabelled with /sup 45/Ca were studied. IL-1..beta.. was found to be the most powerful inducer of bone calcium loss so far known. Maximal activity (2.5 times the control rate of calcium loss) was induced by IL-1..beta.. at concentrations between 1 x 10/sup -10/ M to 6 x 10/sup -12/ M. With IL-1..cap alpha.. maximal activity (1.5 times the control rate of calcium loss) was obtained at 6 x 10/sup -10/ M. With bovine PTH (1-34) maximal activity (1.8 times the control rate of calcium loss) was obtained at 1 x 10/sup -8/ M. With PGE/sub 2/ maximal activity (1.6 times the control rate of calcium loss) was obtained at 1 x 10/sup -7/ M. The calcium loss induced by IL-1..beta.. was inhibited in the presence of 1 x 10/sup -7/ M indomethacin, 5 x 10/sup -5/ M naproxen or ketorolac, or 5 x 10/sup -6/ M cyclohexamide. These findings suggest that protein synthesis and prostaglandin formation are required to mediate bone demineralization induced by IL-1..beta...

  19. Radiative corrections to e/sup +/e/sup -/ reactions to all orders in. cap alpha. using the renormalization group

    SciTech Connect

    Tsai, Y.S.

    1983-01-01

    Renormalization group technique is used to improve the accuracy of the lowest order radiative corrections in QED. The exponentiation of infrared terms comes automatically. It also leads to exponentiation of the vertex functions. It predicts the existence of conversion of photons into pairs and the result agrees with the Kroll-Wada relation. Kinoshita-Lee-Nauenberg cancellation of mass singularities occurs to all order in ..cap alpha.. in leading log approximation in the final state if we sum over all the final states. Higher order corrections to the order ..cap alpha../sup 3/ asymmetry is shown to be small. The results are used to derive useful formulas for the radiative corrections to processes such as e/sup +/e/sup -/ ..-->.. ..mu../sup +/..mu../sup -/, e/sup +/e/sup -/ ..-->.. ..mu../sup +/..mu../sup -/..gamma.., e/sup +/e/sup -/ ..-->.. hadron continuum, e/sup +/e/sup -/ ..-->.. very narrow resonance such as phi, and e/sup +/e/sup -/ ..-->.. not very narrow resonance such as Z/sup 0/.

  20. Jet physics in e/sup +/e/sup -/ annihilation: evidence for the running of. cap alpha. /sub s/

    SciTech Connect

    Bethke, S.

    1988-03-01

    The energy dependence of the relative production rate of 3-jet events is studied in hadronic e/sup +/e/sup -/ annihilation events at centre of mass energies between 22 and 56 GeV, using the data of the JADE, MARK-II and AMY collaborations at PETRA, PEP and TRISTAN. Three jet events are defined by a jet finding algorithm which is closely related to the definition of resolvable jets used in O(..cap alpha../sub s//sup 2/) perturbative QCD calculations, where the relative production rate of 3-jet events is roughly proportional to the strong coupling strength, ..cap alpha../sub s/. The observed production rates of 3-jet events decreases significantly with increasing centre of mass energy. The results, which are independent of fragmentation model calculations, can be directly compared to theoretically calculated jet production rates and are in good agreement with the QCD expectations of a running coupling strength, while the hypothesis of an energy independent coupling constant can be excluded with a significance of 5 standard deviations. Based on these results, the presented jet analysis also provides the possibility to detect first signs of the production of new and heavy particles in the early stage of data taking at SLC and LEP.

  1. Genomic clone encoding the. cap alpha. chain of the OKM1, LFA-1, and platelet glycoprotein IIb-IIIa molecules

    SciTech Connect

    Cosgrove, L.J.; Sandrin, M.S.; Rajasekariah, P.; McKenzie, I.F.C.

    1986-02-01

    LFA-1, an antigen involved in cytolytic T lymphocyte-mediated killing, and Mac-1, the receptor for complement component C3bi, constitute a family of structurally and functionally related cell surface glycoproteins involved in cellular interactions. In both mouse and man, Mac-1 (OKM1) and LFA-1 share a common 95-kDa ..beta.. subunit but are distinguished by their ..cap alpha.. chains, which have different cellular distributions, apparent molecular masses (165 and 177 kDa, respectively), and peptide maps. The authors report the isolation of a genomic clone from a human genomic library that on transfection into mouse fibroblasts produced a molecule(s) reactive with monoclonal antibodies to OKM1, to LFA-1, and to platelet glycoprotein IIb-IIIa. This gene was cloned by several cycles of transfection of L cells with a human genomic library cloned in lambda phase Charon 4A and subsequent rescue of the lambda phage. Transfection with the purified recombinant lambda DNA yielded a transfectant that expressed the three human ..cap alpha.. chains of OKM1, LFA-1, and glycoprotein IIb-IIIa, presumably in association with the murine ..beta.. chain.

  2. Nomogram for determination of the primary and secondary. cap alpha. /sub 1/-fraction in pitch

    SciTech Connect

    Shuvalov, V.I.; Mochalov, V.V.

    1983-01-01

    The relationship between the quinoline - insoluble alpha (1) fraction in coal pitch and mechanical properties of the pitch is studied. A nomogram is developed which allows classification of pitches. (KAW)

  3. Synthesis and solution conformation of the type 2 blood group oligosaccharide. cap alpha. LFuc(1. -->. 2). beta. DGal(1. -->. 4). beta. DGlcNAc

    SciTech Connect

    Rosevear, P.R.; Nunez, H.A.; Barker, R.

    1982-03-16

    Partially purified glycosyltransferases and chemically synthesized sugar nucleotides have been used to prepare a number of oligosaccharides related to the type 2 (human) blood group (H) substance. The following oligosaccharides were prepared and purified by ion-exchange and gel-filtration chromatography: ..cap alpha..LFuc(1..-->..2)-..beta..DGal(1..-->..4)..beta..DGlcNAc-hexanolamine, ..cap alpha..LFuc(1..-->..2)..beta..D(1-/sup 13/C)Gal(1..-->..4)..beta..DGlcNAc-hexanolamine, ..cap alpha..L(1-/sup 13/C)Fuc(1..-->..2)..beta..D(1-/sup 13/C)Gal(1..-->..4)..beta..DGlcNAc-hexanolamine, ..cap alpha..L(1-/sup 13/C)-Fuc(1..-->..2)..beta..D(1-/sup 13/C)Gal(1..-->..4)..beta..DGlcNAc, ..cap alpha..LFuc(1..-->..2)..beta..D-(1-/sup 13/C)Gal(1..-->..4)..beta..DGlcNAc, ..cap alpha..L(1-/sup 13/C)Fuc(1..-->..2)..beta..D(1-/sup 13/C)-Gal(1..-->..4)..beta..DGlc, ..cap alpha..LFuc(1..-->..2)..beta..D(1-/sup 13/C)Gal-hexanolamine, ..cap alpha..L(1-/sup 13/C)Fuc(1..-->..2)..beta..D(1-/sup 13/C)Gal-ethanol, ..cap alpha..LFuc(1..-->..2)..beta..D-(1-/sup 13/C)Gal-ethanol, ..cap alpha..L(1-/sup 13/C)Fuc(1..-->..2)..beta..DGal-ethanol and ..cap alpha..LFuc(1..-->..2)..beta..D(2-/sup 13/C)Gal-ethanol. Specific /sup 13/C enrichment and comparison with /sup 13/C-enriched model compounds allowed unambiguous assignment of /sup 13/C resonances. Fucosylation at O2 of ..beta..DGal(1..-->..4)..beta..DGlcNAc-hexanolamine caused a 5.6 ppm downfield shift of the C2 resonance of Gal. Fucosylation of the disaccharide ..beta..DGal(1..-->..4)DGlcNAc resulted in a similar pattern of chemical shift changes. Interresidue coupling constants (/sup 3/J/sub C1-C1'/ approx. = 1.5 Hz observed as line broadening, /sup 3/J/sub H1-C2'/ approx. = 3.2 Hz, /sup 3/J/sub C1'-C3''/ approx. = 0 Hz, /sup 3/J/sub C1'-C5''/ approx. = 1.0 Hz observed as line broadening, and /sup 2/J/sub C1'-C4''/ approx. = 1.5 Hz) in the enriched oligosaccharides allowed estimation of the most abundant conformer for the Phi and Psi torsion

  4. X-ray magnetic circular dichroism and small angle neutron scattering study of thiol capped gold nanoparticles.

    SciTech Connect

    de la Venta, J.; Bouzas, V.; Pucci, A.; Laguna-Marco, M. A.; Haskel, D.; Pinel, E. F.; te Velthuis, S. G. E.; Hoffmann, A.; Lal, J.; Bleuel, M.; Ruggeri, G.; de Julian, C.; Garcia, M. A.; Univ. Complutense de Madrid; Inst. de Magnetismo Aplicado UCM; Univ. Pisa; Univ. di Padova

    2009-11-01

    X-ray magnetic circular dichroism (XMCD) and Small Angle Neutron Scattering (SANS) measurements were performed on thiol capped Au nanoparticles (NPs) embedded into polyethylene. An XMCD signal of 0.8 {center_dot} 10{sup -4} was found at the Au L{sub 3} edge of thiol capped Au NPs embedded in a polyethylene matrix for which Superconducting Quantum Interference Device (SQUID) magnetometry yielded a saturation magnetization, M{sub s}, of 0.06 emu/g{sub Au}. SANS measurements showed that the 3.2 nm average-diameter nanoparticles are 28% polydispersed, but no detectable SANS magnetic signal was found with the resolution and sensitivity accessible with the neutron experiment. A comparison with previous experiments carried out on Au NPs and multilayers, yield to different values between XMCD signals and magnetization measured by SQUID magnetometer. We discuss the origin of those differences.

  5. Electronic structure of the bcc transition metals: Thermoreflectance studies of bulk V, Nb, Ta, and. cap alpha. TaH/sub x/

    SciTech Connect

    Rosei, R.; Colavita, E.; Franciosi, A.; Weaver, J.H.; Peterson, D.T.

    1980-04-15

    Thermoreflectance studies of bulk samples of V, Nb, Ta, and ..cap alpha..-phase TaH/sub x/ are reported and the results interpreted in terms of recent band calculations. The first interband transition is identified as a transition involving the ..sigma.. band at E/sub F/. An M/sub 3/ critical-point transition is attributed to states at N. Significant changes induced by interstitial hydrogen in solid solution ..cap alpha..-TaH/sub x/ are observed and interpreted as due to hybridization and lowering of the N/sup prime//sub 1/ eigenenergy.

  6. Workshop on A/sup. cap alpha. / physics. Copies of transparencies

    SciTech Connect

    Voyvodic, L.

    1982-03-04

    This one-day workshop focussed on A-dependent effects in high energy particle production. The sessions covered: hard scattering; soft collisions; Tevatron experiments and idea sessions. The report is a collection of vugraphs used. (GHT)

  7. Neutron production from (. cap alpha. ,n) reactions and spontaneous fission in ThO/sub 2/, UO/sub 2/, and (U,Pu)O/sub 2/ fuels

    SciTech Connect

    Perry, R.T.; Wilson, W.B.

    1981-06-01

    Available alpha-particle stopping cross-section and /sup 17/ /sup 18/O(..cap alpha..,n) cross-section data were adjusted, fitted, and used in calculating the thick-target neutron production function for alpha particles below 10 MeV in oxide fuels. The spent UO/sub 2/ function produced was folded with actinide decay spectra to determine (..cap alpha..,n) neutron production by each of 89 actinides. Spontaneous-fission (SF) neutron production for 40 actinides was calculated as the product of anti ..nu..(SF) and SF branching-fraction values accumulated or estimated from available data. These contributions and total neutron production in spent UO/sub 2/ fuel are tabulated and, when combined with any calculated inventory, describe the spent UO/sub 2/ neutron source. All data are tabulated and methodology is described to permit easy extension to specialized problems.

  8. Measurements of Nascent Soot Using a Cavity Attenauted Phase Shift (CAPS)-based Single Scattering Albedo Monitor

    NASA Astrophysics Data System (ADS)

    Freedman, A.; Onasch, T. B.; Renbaum-Wollf, L.; Lambe, A. T.; Davidovits, P.; Kebabian, P. L.

    2015-12-01

    Accurate, as compared to precise, measurement of aerosol absorption has always posed a significant problem for the particle radiative properties community. Filter-based instruments do not actually measure absorption but rather light transmission through the filter; absorption must be derived from this data using multiple corrections. The potential for matrix-induced effects is also great for organic-laden aerosols. The introduction of true in situ measurement instruments using photoacoustic or photothermal interferometric techniques represents a significant advance in the state-of-the-art. However, measurement artifacts caused by changes in humidity still represent a significant hurdle as does the lack of a good calibration standard at most measurement wavelengths. And, in the absence of any particle-based absorption standard, there is no way to demonstrate any real level of accuracy. We, along with others, have proposed that under the circumstance of low single scattering albedo (SSA), absorption is best determined by difference using measurement of total extinction and scattering. We discuss a robust, compact, field deployable instrument (the CAPS PMssa) that simultaneously measures airborne particle light extinction and scattering coefficients and thus the single scattering albedo (SSA) on the same sample volume. The extinction measurement is based on cavity attenuated phase shift (CAPS) techniques as employed in the CAPS PMex particle extinction monitor; scattering is measured using integrating nephelometry by incorporating a Lambertian integrating sphere within the sample cell. The scattering measurement is calibrated using the extinction measurement of non-absorbing particles. For small particles and low SSA, absorption can be measured with an accuracy of 6-8% at absorption levels as low as a few Mm-1. We present new results of the measurement of the mass absorption coefficient (MAC) of soot generated by an inverted methane diffusion flame at 630 nm. A value

  9. Mechanism of pion production in {alpha}p scattering at 1 GeV/nucleon

    SciTech Connect

    Alkhazov, G. D.; Prokofiev, A. N. Smirnov, I. B.; Strokovsky, E. A.

    2012-09-15

    An analysis of the experimental data on one-pion and two-pion production in the p({alpha}, {alpha} Prime )X reaction studied in a semi-exclusive experiment at an energy of E{sub {alpha}} = 4.2 GeV has been performed. The obtained results demonstrate that the inelastic {alpha}-particle scattering on the proton at the energy of the experiment proceeds either through excitation and decay of the {Delta} resonance in the projectile {alpha} particle, or through excitation in the target proton of the Roper resonance, which decays into a nucleon and a pion, or a nucleon and a {sigma} meson-a system of two pions in the isospin I = 0, S-wave state.

  10. K-alpha conversion efficiency measurments for x-ray scattering in inertial confinement fusion plasmas

    SciTech Connect

    Kritcher, A L; Neumayer, P; Urry, M K; Robey, H; Niemann, C; Landen, O L; Morse, E; Glenzer, S H

    2006-11-21

    The conversion efficiency of ultra short-pulse laser radiation to K-{alpha} x-rays has been measured for various chlorine-containing targets to be used as x-ray scattering probes of dense plasmas. The spectral and temporal properties of these sources will allow spectrally-resolved x-ray scattering probing with picosecond temporal resolution required for measuring the plasma conditions in inertial confinement fusion experiments. Simulations of x-ray scattering spectra from these plasmas show that fuel capsule density, capsule ablator density, and shock timing information may be inferred.

  11. Development of an alpha scattering instrument for heavy element detection in surface materials

    NASA Technical Reports Server (NTRS)

    Turkevich, A. L.; Economou, T.; Blume, E.; Anderson, W.

    1974-01-01

    The development and characteristics of a portable instrument for detecting and measuring the amounts of lead in painted surfaces are discussed. The instrument is based on the ones used with the alpha scattering experiment on the Surveyor lunar missions. The principles underlying the instrument are described. It is stated that the performance tests of the instrument were satisfactory.

  12. K-(alpha) X-ray Thomson Scattering From Dense Plasmas

    SciTech Connect

    Kritcher, A L; Neumayer, P; Castor, J; Doppner, T; Falcone, R W; Landen, O L; Lee, H J; Lee, R W; Morse, E C; Ng, A; Pollaine, S; Price, D; Glenzer, S H

    2009-05-07

    Spectrally resolved Thomson scattering using ultra-fast K-{alpha} x-rays has measured the compression and heating of shocked compressed matter. The evolution and coalescence of two shock waves traveling through a solid density LiH target were characterized by the elastic scattering component. The density and temperature at shock coalescence, 2.2 eV and 1.7 x 10{sup 23}cm{sup -3}, were determined from the plasmon frequency shift and the relative intensity of the elastic and inelastic scattering features in the collective scattering regime. The observation of plasmon scattering at coalescence indicates a transition to the dense metallic state in LiH. The density and temperature regimes accessed in these experiments are relevant for inertial confinement fusion experiments and for the study of planetary formation.

  13. Effect of trihydroxyoctadecadienoic acids on blood levels of prostaglandins E/sub 2/ and F/sub 2. cap alpha. / and of 5-hydroxyeicosatetraenoic acid in rats with alloxan diabetes

    SciTech Connect

    Vartanyan, G.S.; Panosyan, A.G.; Karagezyan, K.G.; Gevorkyan, G.A.

    1986-09-01

    The effect of the trihydroxyoctadecadienoic acids (THODA) fraction on blood levels of some eicosanoids and, in particular, of prostaglandins E/sub 2/ and F/sub 2..cap alpha../(PGE/sub 2/ and PGF/sub 2..cap alpha../), and 5-hydroxyeicosatetraenoic acid (5-HETE) in rats with alloxan diabetes was studied. Concentrations of PGE/sub 2/, PGF/sub 2..cap alpha../, and 5-HETE in peripheral blood plasma were determined by radioimmunoassay. To assess the loss of substances during extraction and chromatography, /sup 3/H/sub 8/-PGE/sub 2/, /sup 3/H/sub 8/-PGF/sub 2..cap alpha.., and /sup 3/H/sub 8/-5-HETE were used. Plasma PGE/sub 2/, PGF/sub 2..cap alpha../, and 5-HETE levels in albino rats with alloxan diabetes and after injection of THODA are shown.

  14. Hydrogen Balmer alpha intensity distributions and line profiles from multiple scattering theory using realistic geocoronal models

    NASA Technical Reports Server (NTRS)

    Anderson, D. E., Jr.; Meier, R. R.; Hodges, R. R., Jr.; Tinsley, B. A.

    1987-01-01

    The H Balmer alpha nightglow is investigated by using Monte Carlo models of asymmetric geocoronal atomic hydrogen distributions as input to a radiative transfer model of solar Lyman-beta radiation in the thermosphere and atmosphere. It is shown that it is essential to include multiple scattering of Lyman-beta radiation in the interpretation of Balmer alpha airglow data. Observations of diurnal variation in the Balmer alpha airglow showing slightly greater intensities in the morning relative to evening are consistent with theory. No evidence is found for anything other than a single sinusoidal diurnal variation of exobase density. Dramatic changes in effective temperature derived from the observed Balmer alpha line profiles are expected on the basis of changing illumination conditions in the thermosphere and exosphere as different regions of the sky are scanned.

  15. SU-E-T-59: Calculations of Collimator Scatter Factors (Sc) with and Without Custom-Made Build-Up Caps for CyberKnife

    SciTech Connect

    Wokoma, S; Yoon, J; Jung, J; Lee, S

    2014-06-01

    Purpose: To investigate the impact of custom-made build-up caps for a diode detector in robotic radiosurgery radiation fields with variable collimator (IRIS) for collimator scatter factor (Sc) calculation. Methods: An acrylic cap was custom-made to fit our SFD (IBA Dosimetry, Germany) diode detector. The cap has thickness of 5 cm, corresponding to a depth beyond electron contamination. IAEA phase space data was used for beam modeling and DOSRZnrc code was used to model the detector. The detector was positioned at 80 cm source-to-detector distance. Calculations were performed with the SFD, with and without the build-up cap, for clinical IRIS settings ranging from 7.5 to 60 mm. Results: The collimator scatter factors were calculated with and without 5 cm build-up cap. They were agreed within 3% difference except 15 mm cone. The Sc factor for 15 mm cone without buildup was 13.2% lower than that with buildup. Conclusion: Sc data is a critical component in advanced algorithms for treatment planning in order to calculate the dose accurately. After incorporating build-up cap, we discovered differences of up to 13.2 % in Sc factors in the SFD detector, when compared against in-air measurements without build-up caps.

  16. Metal to ligand charge-transfer photochemistry of metal-metal bonded complexes. 5. ESR spectra of stable rhenium-. cap alpha. -diimine and spin-trapped manganese-. cap alpha. -diimine radicals

    SciTech Connect

    Andrea, R.R.; de Lange, W.G.J.; van der Graaf, T.; Rijkhoff, M.; Stufkens, D.J.; Oskam, A.

    1988-05-01

    Irradiation (lambda greater than or equal to 320 nm) of (CO)/sub 5/MM'(CO)/sub 3/L and Ph/sub 3/SnM'(CO)/sub 3/L (M, M' = Mn, Re; L = ..cap alpha..-diimine = 2,2'-bipyridine, 1,10-phenanthroline, pyridine-2-carbaldehyde imine, and 1,4-diaza-1,3-butadiene) leads to homolysis of the metal-metal bond yielding fairly stable solvated radicals SM'(CO)/sub 3/L/sup ./. These paramagnetic species have been studied by ESR spectroscopy in solution directly or by using nitroso-2,2-dimethylpropane as a spin-trapping reagent. The ESR spectra show extensive hyperfine splittings of the unpaired electron with the nuclei /sup 14/N, /sup 1/H, and /sup 55/Mn or /sup 185,187/Re. From the observed and computer-simulated coupling constants important information could be derived about the electronic structure of the singly occupied molecular orbital (SOMO). After in situ addition of P(OPh)/sub 3/, P(OMe)/sub 3/, or pyridine (=L') to Re(CO)/sub 3/(t-Bu-DAB)/sup ./, the new paramagnetic adducts axial-(L')Re(CO)/sub 3/(t-Bu-DAB)/sup ./ could be identified.

  17. Elastic alpha scattering experiments and the alpha-nucleus optical potential at low energies

    SciTech Connect

    Mohr, P.; Kiss, G.G.; Fülöp, Zs.; Galaviz, D.; Gyürky, Gy.; Somorjai, E.

    2013-11-15

    High precision angular distribution data of (α,α) elastic scattering are presented for the nuclei {sup 89}Y, {sup 92}Mo, {sup 106,110,116}Cd, {sup 112,124}Sn, and {sup 144}Sm at energies around the Coulomb barrier. Such data with small experimental uncertainties over the full angular range (20–170°) are the indispensable prerequisite for the extraction of local optical potentials and for the determination of the total reaction cross section σ{sub reac}. A systematic fitting procedure was applied to the experimental scattering data presented to obtain comprehensive local potential parameter sets that are composed of a real folding potential and an imaginary potential of Woods–Saxon surface type. The potential parameters obtained were used in turn to construct a new systematic α-nucleus potential with very few parameters. Although this new potential cannot reproduce the angular distributions with the same small deviations as the local potential, the new potential is able to predict the total reaction cross sections for all cases under study.

  18. Characterization of the transport of. cap alpha. -methylaminoisobutyric acid by a human intestinal cell line (HT-29)

    SciTech Connect

    Bergin, L.; Dantzig, A.H.

    1986-03-01

    Under certain growth conditions, the human colon adenocarcinoma cell line HT-29 exhibits intestinal enterocyte-like properties. The differentiated cells possess a brush border with the enzyme markers (aminopeptidase and sucrase) normally associated with the intestine. To aid in the characterization of the transport properties of these cells, the uptake of a non-metabolizable amino acid analog, /sup 14/C-..cap alpha..-methylaminoisobutyric acid (MeAIB) as examined in the HT-29-Al subclone which possesses a brush border. The cells exhibited a time-dependent uptake of MeAIB which was concentrative and sodium-dependent. The pH optimum for uptake was about 7.8. Uptake was inhibited by low temperature, 1 mM ouabain, or 0.5 mM dinitrophenol. A 1 hr-preincubation of the cells in an isotonic KCl solution resulted in a decreased uptake rate, suggesting that a negative membrane potential is important for MeAIB uptake. The rate of 0.5 mM MeABIB uptake was inhibited by 40 to 90% by 5 mM of certain small neutral amino acids such as Ala, Ser, Pro, Gly, met but not by acidic or basic amino acids such as Asp, Glu, Arg or Lys. The uptake of MeAIB appears to be mediated by an amino acid transport carrier similar to the A-system described previously for Chinese hamster ovary cells.

  19. Cap-dependent and hepatitis C virus internal ribosome entry site-mediated translation are modulated by phosphorylation of eIF2alpha under oxidative stress.

    PubMed

    MacCallum, Paul R; Jack, Samantha C; Egan, Philip A; McDermott, Benjamin T; Elliott, Richard M; Chan, Shiu-Wan

    2006-11-01

    Chronic hepatitis C is often associated with oxidative stress. Hepatitis C virus (HCV) utilizes an internal ribosome entry site (IRES) element for translation, in contrast to cap-dependent translation of the majority of cellular proteins. To understand how virus translation is modulated under oxidative stress, HCV IRES-mediated translation was compared with cap-dependent translation using a bicistronic reporter construct and hydrogen peroxide (H2O2) as a stress inducer. In H2O2-sensitive HeLa cells, H2O2 repressed translation in a time- and dose-dependent manner, concomitant with the kinetics of eIF2alpha phosphorylation. A phosphomimetic of eIF2alpha, which mimics the structure of the phosphorylated eIF2alpha, was sufficient to repress translation in the absence of H2O2. In H2O2-resistant HepG2 cells, H2O2 activated both HCV IRES-mediated and cap-dependent translation, associated with an increased level of phospho-eIF2alpha. It was postulated that H2O2 might stimulate translation in HepG2 cells via an eIF2alpha-independent mechanism, whereas the simultaneous phosphorylation of eIF2alpha repressed part of the translational activities. Indeed, the translational repression was released in the presence of a non-phosphorylatable mutant, eIF2alpha-SA, resulting in further enhancement of both translational activities after exposure to H2O2. In HuH7 cells, which exhibited an intermediate level of sensitivity towards H2O2, both HCV IRES-mediated and cap-dependent translational activities were upregulated after treatment with various doses of H2O2, but the highest level of induction was achieved with a low level of H2O2, which may represent the physiological level of H2O2. At this level, the HCV IRES-mediated translation was preferentially upregulated compared with cap-dependent translation. PMID:17030858

  20. HF ground scatter from the polar cap: Ionospheric propagation and ground surface effects

    NASA Astrophysics Data System (ADS)

    Ponomarenko, P. V.; St. Maurice, J.-P.; Hussey, G. C.; Koustov, A. V.

    2010-10-01

    In addition to being scattered by the ionospheric field-aligned irregularities, HF radar signals can be reflected by the ionosphere toward the Earth and then scattered back to the radar by the rugged ground surface. These ground scatter (GS) echoes are responsible for a substantial part of the returns observed by HF radars making up the Super Dual Auroral Radar Network (SuperDARN). While a GS component is conventionally used in studying ionosphere dynamics (e.g., traveling ionospheric disturbances, ULF waves), its potential in monitoring the state of the scattering surface remains largely unexploited. To fill this gap, we investigated diurnal and seasonal variation of the ground echo occurrence and location from a poleward-looking SuperDARN radar at Rankin Inlet, Canada. Using colocated ionosonde information, we have shown that seasonal and diurnal changes in the high-latitude ionosphere periodically modulate the overall echo occurrence rate and spatial coverage. In addition, characteristics of GS from a particular geographic location are strongly affected by the state of the underlying ground surface. We have shown that (1) ice sheets rarely produce detectable backscatter, (2) mountain ranges are the major source of GS as they can produce echoes at all seasons of the year, and (3) sea surface becomes a significant source of GS once the Arctic sea ice has melted away. Finally, we discuss how the obtained results can expand SuperDARN abilities in monitoring both the ionosphere and ground surface.

  1. Measuring chlorophyll. cap alpha. and /sup 14/C-labeled photosynthate in aquatic angiosperms by the use of a tissue solubilizer. [/sup 14/C-labelled photosynthate

    SciTech Connect

    Beer, S.; Stewart, A.J.; Wetzel, R.G.

    1982-01-01

    A compound that quantitatively correlated with chlorophyll ..cap alpha.. could be measured fluorometrically in the extracts of leaves of three aquatic angiosperms (Myriophyllum heterophyllum Michx., Potamogeton crispus L., Elodea canadensis Michx.) treated with the tissue solubilizer BTS-450. Fluorescent characteristics of the solubilized plant tissues were stable for several weeks in the dark at temperatures up to 60/sup 0/C but rapidly degraded in sunlight or when acidified. /sup 14/C-Labeled photosynthate, which had been fixed by leaf discs during 1- to 10-hour exposure to H/sup 14/CO/sub 3/, was also readily extracted by the tissue solubilizer. Solubilizer extraction can, therefore, be used to determine both chlorophyll ..cap alpha.. content and /sup 14/C incorporation rates in the same leaf sample. The method is practical, because no grinding is required, the fluorescent characteristics of the extracts are stable, and analyses can be performed with very little plant material (about 3 milligrams).

  2. cap alpha. /sub 2/-Adrenergic receptors in platelet membranes of depressed patients: no change in number of /sup 3/H-yohimbine affinity

    SciTech Connect

    Daiguji, M.I.; Meltzer, H.Y.; Tong, C.; U'Pritchard, D.C.; Young, M.; Kravitz, H.

    1981-11-16

    The ..cap alpha../sub 2/-adrenergic receptor density in platelet membranes from normal controls and depressed patients was studied using /sup 3/H-yohimbine, a potent ..cap alpha../sub 2/-adrenergic antagonist, as a radioligand. The KD values of /sup 3/H-yohimbine in control and depressed patient samples were 0.92 +/- 0.07 nM and 0.97 +/- 0.06 nM, respectively. The Bmax values of controls and depressed patients were 240 +/- 19 fmoles/mg protein (125 +/- 13 receptor/platelet, R/PL) and 204 +/- 20 fmoles/mg protein (130 +/- 14 R/PL), respectively. There were no significant differences between the KD and Bmax values of the two groups.

  3. Bioconversion of. cap alpha. -(/sup 14/C)Zearalenol and. beta. -(/sup 14/C)Zearalenol into (/sup 14/C)Zearalenone by Fusarium roseum Gibbosum

    SciTech Connect

    Richardson, K.E.; Hagler, W.M. Jr.; Hamilton, P.B.

    1984-06-01

    Cultures of Fusarium roseum Gibbosum on rice were treated with (/sup 14/C)zearalenone, ..cap alpha..-(/sup 14/C)zearalenol, or ..beta..-(/sup 14/C)zearalenol to determine whether a precursor-product relationship exists among these closely related fungal metabolites. Culture extracts were purified by silica gel column chromatography and fractionated by high-pressure liquid chromatography, and the level of radioactivity was determined. Within 7 days, the ..beta..-(/sup 14/C)zearalenol was converted to zearalenone, and no residual ..beta..-(/sup 14/C)zearalenol was detectable. Most of the ..cap alpha..-(/sup 14/C)zearalenol added was also converted into zearalenone within 14 days. In cultures treated with (/sup 14/C)zearalenone, no radioactivity was noted in any other components.

  4. Isophotes of a field in the Cygnus loop photographed in the (O III) and (N II)+H. cap alpha. lines

    SciTech Connect

    Sitnik, T.G.; Toropova, M.S.

    1982-11-01

    From interference-filter image-tube photographs of a 9' field in the western part of the Cygnus Loop supernova remnant, taken in the lambda5007 (O III) and lambdalambda 6584, 6563 (N II) + H..cap alpha.. lines, sets of isophotes are derived by an equidensitometry technique based on the Sabattier effect. The emission regions in these lines exhibit a relative displacement, interpreted as evidence for radiative cooling of the gas behind the shock generated in the supernova outburst. An explanation is offered for the differing morphology of the nebular filaments in the (O III) and (N II) + H..cap alpha.. lines. The anomalously high I/sub Otsi/II/I/sub H/..beta.. intensity ratio may reflect a spatial separation of the corresponding emission zones.

  5. Chiral effects on the /sup 13/C resonances of. cap alpha. -tocopherol and related compounds. A novel illustration of Newman's rule of six

    SciTech Connect

    Brownstein, S.; Burton, G.W.; Hughes, L.; Ingold, K.U.

    1989-02-03

    The 100-MHz /sup 13/C NMR spectrum of (2R,4'R,8'R)-..cap alpha..-tocopherol (natural vitamin E) has been completely assigned with the aid of a number of selectively deuteriated (2R,4'R,8'R)-..cap alpha..-tocopherols. The /sup 13/C NMR spectrum of (2RS,4'RS,8'RS)-..cap alpha..-tocopherol (all-racemic, synthetic vitamin E) has also been measured. Many of the individual carbons in this all-racemic mixture of eight ..cap alpha..-tocopherol stereoisomers give more than one resonance with eight of the carbons (2-CH/sub 3/, 2',3',4',4'-CH/sub 3/, 5', 8', and 9') giving the maximum number of four resonances from each of the four enantiomeric pairs; these resonances have also been assigned. The structurally related 5'-hydroxy-2-(4',8',12'-trimethyltridecyl)-2,4,6,7-tetramethyl-2,3,-dihydrobenzofuran (HTDBF) has been synthesized for the first time in the 2R,4'R,8'R and 2S,4'R,8'R configurations and their /sup 13/C resonances have been assigned. In its all-racemic form this compound also shows up to four resonances from a single carbon. Related observations have been made with phytol and isophytol. A careful examination of these chirally induced chemical shift differences for the individual carbon atoms, ..delta.., reveals a bond-alternation effect with maxima at a separation of one, three, and five bonds from the closest chiral center and with the maximum at a five-bond separation being greater than that at a three-bond separation. 32 references, 2 figures, 4 tables.

  6. Synthesis of 8-phenyl-10H-pyrido(1,2-. cap alpha. )indole salts from 2,3,3-trimethyl-3H-indole chlorides with cinnamaldehyde

    SciTech Connect

    Shachkus, A.A.; Degutis, Yu.A.

    1987-10-01

    Reaction of 2,3,3-trimethyl-3H-indole chloride with cinnamic and 4-dimethylaminocinnamic aldehydes led to salts of 8-phenyl and 8-(4-dimethylaminophenyl)-10,10-dimethyl-10H-pyrido(1,2-..cap alpha..)indole. PMR spectra were recorded on a Tesla BS-487C (80 MHz) instrument (internal standard HMDS) and IR spectra on a UR-20 spectrometer (KBr pellets).

  7. Comparative study of action of cell wall proteinases from various strains of Streptococcus cremoris on bovine. cap alpha. /sub s1/sup -//,. beta. -, and kappa-casein

    SciTech Connect

    Visser, S.; Exterkate, F.A.; Slangen, C.J.; de Veer, G.J.C.M.

    1986-11-01

    Experiments are described in which partially purified cell wall proteinases of eight strains of S. cremoris, including strain HP, were compared in their action on ..cap alpha../sub s1/sup -//, ..beta..-, and kappa-casein, as visualized by starch gel electrophoresis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and TLC, and also in their action on methyl-/sup 14/C-labeled ..beta..-casein.

  8. In-111 chelate conjugates of human transferrin (HTr) and mouse monoclonal anti human transferrin receptor antibody (. cap alpha. HTrR MoAb) for tumor imaging

    SciTech Connect

    Goodwin, D.A.; Meares, C.F.; Diamanti, C.I.; McCall, M.; McTigue, M.; Torti, F.; Martin, B.

    1984-01-01

    At least one of the major pathways of uptake of the commonly used tumor scanning agent Ga-67 is via the transferrin receptor. This suggested the use of stably radio-labeled HTr, and ..cap alpha..HTrR MoAb for tumor imaging in humans. HTr and mouse ..cap alpha..HTrR MoAb were alkylated with 1-(parabromacetamidobenzyl)-EDTA. The mM Alkylproteins, approx. =1 chelate/molecule were labeled with 1-3 mCi In-111 citrate pH/sub 5/ (Sp Act approx. = 100-300 Ci/m mole). Images were made 24 hours after 1 mCi IV and in some patients blood levels, urine excretion and digitized whole body scans were obtained at 1, 24,48 and 96 hours post injection. Ten patients with biopsy proven prostate cancer were studied with In-111 HTr, and four with In-111 ..cap alpha.. HTrR MoAb; all had positive mets on bone scan. In-111 HTr persisted in the circulation with a T1/2 of approx. = four days, approx. = 5%/day being excreted in the urine, to a total of approx. = 60% in 21 days. Nine of ten scans were false negative due to the high blood background. In-111 ..cap alpha..HTrR disappeared rapidly from the blood; with most in the bone marrow at 24 hours. ROI analysis of three patients showed whole body 94% at 24 hours, 89% at 48 hours, and 82% at 96 hours (T1/2 = 10.7 days); liver 19% at 1 hour, 25% at 24 hours, and 21% at 96 hours; spleen 3% at 1 hour, 8% at 24 hours, 7.3% at 48 hours, and 3% at 96 hours. The high bone marrow background allowed only a few of the bone mets seen as bone scan to be visualized. Other tumor types not located in bone may be more easily seen.

  9. Effects of kinase inhibitors and potassium phosphate (KPi) on site-specific phosphorylation of branched chain. cap alpha. -ketoacid dehydrogenase (BCKDH)

    SciTech Connect

    Kuntz, M.J.; Shimomura, Y.; Ozawa, T.; Harris, R.A.

    1987-05-01

    BCKDH is phosphorylated by a copurifying kinase at two serine residues on the El..cap alpha.. subunit. Phosphorylation of both sites occurs at about the same rate initially, but inactivation is believed associated only with site 1 phosphorylation. The effects of KPi and known inhibitors of BCKDH kinase, ..cap alpha..-chloroisocaproate (CIC) and branched chain ..cap alpha..-ketoacids (BCKA), on the phosphorylation of purified rat liver BCKDH were studied. Site-specific phosphorylation was quantitated by thin-layer electrophoresis of tryptic peptides followed by densitometric scanning of autoradiograms. Addition of 5 mM KPi was found necessary to stabilize the BCKDH activity at 37/sup 0/C. Increasing the KPi to 50 mM dramatically increased the CIC and BCKA inhibition of site 1 and site 2 phosphorylation. The finding of enhanced sensitivity of inhibitors with 50 mM KPi may facilitate identification of physiologically important kinase effectors. Regardless of the KPi concentration, CIC and the BCKA showed much more effective inhibition of site 2 than site 1 phosphorylation. Although site 1 is the primary inactivating site, predominant inhibition of site 2 phosphorylation may provide a means of modulating kinase/phosphatase control of BCKDH activity under steady state conditions.

  10. Human immunodeficiency virus contains an epitope immunoreactive with thymosin. cap alpha. /sub 1/ and the 30-amino acid synthetic p17 group-specific antigen peptide HGP-30

    SciTech Connect

    Naylor, P.H.; Naylor, C.W.; Badamchian, M.; Wada, S.; Goldstein, A.L.; Wang, S.S.; Sun, D.K.; Thornton, A.H.; Sarin, P.S.

    1987-05-01

    The authors have reported that an antiserum prepared against thymosin ..cap alpha../sub 1/ (which shares a region of homology with the p17 protein of the acquired immunodeficiency syndrome (AIDS)-associated human immunodeficiency virus) effectively neutralized the AIDs virus and prevented its replication in H9 cells. Using HPLC and immunoblot analysis, they have identified from a clone B, type III human T-lymphotropic virus (HTLV-IIIB) extracts a protein with a molecular weight of 17,000 that is immunoreactive with thymosin ..cap alpha../sub 1/. In contrast, no immunoreactivity was found in retroviral extracts from a number of nonhuman species including feline, bovine, simian, gibbon, and murine retroviruses. Heterologous antiserum prepared against a 30-amino acid synthetic peptide analogue (HGP-30) does not cross-react with thymosin ..cap alpha../sub 1/ but does react specifically with the p17 protein of the AIDS virus in a manner identical to that seen with an HTLV-IIIB p17-specific monoclonal antibody. The demonstration that this synthetic analogue is immunogenic and that antibodies to HGP-30 cross-react not only with synthetic peptide but also with the HTLV-IIIB p17 viral protein provides an additional, and potentially more specific, candidate for development of a synthetic peptide vaccine for AIDS. In addition, the p17 synthetic peptide (HGP-3) may prove to be useful in a diagnostic assay for the detection of AIDS virus infection in seronegative individuals.

  11. Human placental Na/sup +/, K/sup +/-ATPase. cap alpha. subunit: cDNA cloning, tissue expression, DNA polymorphism, and chromosomal localization

    SciTech Connect

    Chehab, F.F.; Kan, Y.W.; Law, M.L.; Hartz, J.; Kao, F.T.; Blostein, R.

    1987-11-01

    A 2.2-kilobase clone comprising a major portion of the coding sequence of the Na/sup +/, K/sup +/-ATPase ..cap alpha.. subunit was cloned from human placenta and its sequence was identical to that encoding the ..cap alpha.. subunit of human kidney and HeLa cells. Transfer blot analysis of the mRNA products of the Na/sup +/, K/sup +/-ATPase gene from various human tissues and cell lines revealed only one band (approx. = 4.7 kilobases) under low and high stringency washing conditions. The levels of expression in the tissues were intestine > placenta > liver > pancreas, and in the cell lines the levels were human erythroleukemia > butyrate-induced colon > colon > brain > HeLa cells. mRNA was undetectable in reticulocytes, consistent with the authors failure to detect positive clones in a size-selected ( > 2 kilobases) lambdagt11 reticulocyte cDNA library. DNA analysis revealed by a polymorphic EcoRI band and chromosome localization by flow sorting and in situ hybridization showed that the ..cap alpha.. subunit is on the short is on the short arm (band p11-p13) of chromosome 1.

  12. A comparison of H-alpha intensity and radio wave scattering on eight low-latitude lines of sight

    NASA Technical Reports Server (NTRS)

    Spangler, Steven R.; Reynolds, Ronald J.

    1990-01-01

    Radio scattering and H-alpha measurements for eight sources in Cygnus are compared. The diameter of the radio scattering disk at 1 GHz is found to be correlated with emission measure as determined from the H-alpha measurements, and that strong radio scattering characterized by a diameter of about 30 milliarcsec is produced in regions with emission measures of about 100/cm exp 6 pc or less. The slope of diameter-emission measure correlation is steeper than would be the case if all lines of sight were characterized by the same turbulent outer scale and modulation index. It is suggested that the lines of sight to unscattered or lightly scattered sources traverse only a diffuse medium which is revealed by H-alpha observations at high latitudes. Heavily scattered sources are viewed through an additional component of interstellar H II which has turbulence with different properties.

  13. Regio- and stereospecificity of 3. cap alpha. -hydroxysteroid/dihydrodiol dehydrogenase for trans-dihydrodiols of polycyclic aromatic hydrocarbons

    SciTech Connect

    Smithgall, T.E.; Harvey, R.G.; Penning, T.M.

    1986-03-01

    Homogeneous 3..cap alpha..-hydroxysteroid/dihydridiol dehydrogenase of rat liver cytosol catalyzes the NAD(P)-dependent oxidation of a variety of trans-dihydrodiols of aromatic hydrocarbons. V/sub max//K/sub m/ ratios indicate that benzenedihydrodiol and the trans-1,2- and trans-7,8-dihydrodiols of 5-methylchrysene are most efficiently oxidized, followed by the trans-7,8-dihydrodiol of benzo(a)pyrene. The enzyme displays rigid regio-selectivity, since it readily oxidizes non-K-region trans-dihydrodiols but not the corresponding K-region isomers. Using circular dichroism spectrometry the stereochemical course of the reaction was monitored. The dehydrogenase preferentially oxidizes the (+)-(1S,2S)-diols of benzene, naphthalene, phenanthrene, and chrysene. Apparent inversion of this preference occurs with the trans-7,8-dihydrodiol of 5-methylchrysene, as the (-)-enantiomer is utilized. No change in the sign of the Cotton Effect is observed following oxidation of the (+/-)-trans-7,8-dihydrodiol of benzo(a)pyrene. Incubation of the (/sup 3/H)-(+/-)-trans-7,8-dihydrodiol of benzo(a)pyrene with the purified dehydrogenase results in greater than 90% utilization of the potent proximate carcinogen, suggesting that both the (-)-(7R,8R)- and (+)-(7S,8S)-isomers are utilized. These data show that the dehydrogenase displays the appropriate regio-and stereospecificity to oxidized both the major and minor non-K-region trans-dihydrodiols that arise from the microsomal metabolism of benzo(a)pyrene in vivo.

  14. Interaction of isocitrate dehydrogenase with (RS)-3-bromo-2-ketoglutarate. A potential affinity label for. cap alpha. -ketoglutarate binding sites

    SciTech Connect

    Hartman, F.C.

    1981-01-01

    The interaction of oxidize nicotine adenine dinucleotide phosphate dependent isocitrate dehydrogenase (from pig heart) with (RS)-3-bromo-2-ketoglutarate was investigated in an effort to evaluate the reagent's potential as a selective reagent for ..cap alpha..-ketoglutarate binding sites. The enzyme is rapidly inactivated by 0.1 mM bromoketoglutarate at pH 7.4. With increasing concentration of reagent, the reaction shows a rate saturation; the minimum inactivation half-time is 3 min and K/sub inact/ for bromoketoglutarate is 250 ..mu..M. Isocitrate and NADP/sup +/ protect against inactivation, while ketoglutarate does not. When tested in the assay that monitors isocitrate oxidation, bromoketoglutarate is a competitive inhibitor (K/sub i/=100 ..mu..M) of the dehydrogenase. As judged by oxidation of NADPH, bromoketoglutarate is also a substrate for isocitrate dehydrogenase, exhibiting a K/sub m/ of 250 ..mu..M and a V/sub max/ comparable to that for isocitrate oxidation. The reduction of bromoketoglutarate is competitively inhibited by isocitrate (K/sub i/=3 ..mu..M) and ketoglutarate (K/sub i/=50 ..mu..M). Like the enzyme-catalyzed oxidation of isocitrate, the reduction of bromoketoglutarate is stereospecific, requires divalent metal ions, and shows absolute specificity for NADPH. However, since CO/sub 2/ is not required for catalytic turnover of bromoketoglutarate, its reduction is likely comparable to that of oxalosuccinate rather than the reductive carboxylation of ketoglutarate. Although bromoketoglutarate, as a substrate for isocitrate dehydrogenase, clearly has affinity for the active site, the irreversible inactivation of the enzyme by the reagent may result from modification outside the active-site region, since inactivation during catalytic turnover of bromoketoglutarate is not observed.

  15. Role of the inhibitory guanine nucleotide regulatory protein in high affinity. cap alpha. /sub 2/ adrenergic agonist binding

    SciTech Connect

    Kim, M.H.

    1987-01-01

    The purpose of this study was to determine whether regulatory protein, N/sub i/ was required for high affinity agonist binding to the a/sub 2/ adrenergic receptor in human platelet membranes. Human platelet membranes treated under alkaline conditions (pH 11.5) exhibited a selective and complete loss of high affinity agonist binding as measured by the parital agonist (/sup 3/H)-p-aminoclonidine and full agonist (/sup 3/H)UK 14,304 in direct binding studies. The binding parameters for (/sup 3/H)UK 14,304 are as follows: for control platelet membranes, the K/sub d/ was 0.88 +/- 0.17 and nM and the B/sub max/ was 280 +/- 20 fmol/mg compared to 1.89 +/- 0.34 nM and 75 fmol/mg for pH 11.5 treated membranes. For (/sup 3/H)p-aminoclonidine, the data for pH 11.5 treated membranes is as follows: B/sub max/ = 100 +/- 20 fmol/mg, K/sub d/ = 3.4 +/- 0.1 nM, compared to control membranes: (best fit with a two site fit) K/sub d1/ = 0.7 nM, K/sub d2/ = 8 nM, B/sub max1/ = 76 fmol/mg, B/sub max2/ = 198 fmol/mg. The ..cap alpha../sub 2/ antagonists, (/sup 3/H)yohimbine, was used to assess the presence of the receptor.

  16. Internode length in Pisum. Gene na may block gibberellin synthesis between ent-7. cap alpha. -hydroxykaurenoic acid and biggerellin A/sub 12/-aldehyde. [Pisum sativum

    SciTech Connect

    Ingram, T.J.; Reid, J.B.

    1987-04-01

    The elongation response of the gibberellin (GA) deficient genotypes na, ls, and lh of peas (Pisum sativum L.) to a range of GA-precursors was examined. Plants possessing gene na did not respond to precursors in the GA biosynthetic pathway prior to GA/sub 12/-aldehyde. In contrast, plants possessing lh and ls responded as well as wild-type plants (dwarfed with AMO-1618) to these compounds. The results suggest that GA biosynthesis is blocked prior to ent-kaurene in the lh and ls mutants and between ent-7..cap alpha..-hydroxykaurenoic acid and GA/sub 12/-aldehyde in the na mutant. Feeds of ent(/sup 3/H)kaurenoic acid and (/sup 2/H)GA/sub 12/-aldehyde to a range of genotypes supported the above conclusions. The na line WL1766 was shown by gas chromatography-mass spectrometry (GC-MS) to metabolize(/sup 2/H)GA/sub 12/-aldehyde to a number of (/sup 2/H)C/sub 19/-GAs including GA/sub 1/. However, there was no indication in na genotypes for the metabolism of ent-(/sup 3/H)kaurenoic acid to these GAs. In contrast, the expanding shoot tissue of all Na genotypes examined metabolized ent-(/sup 3/H)kaurenoic acid to radioactive compounds that co-chromatographed with GA/sub 1/, GA/sub 8/, GA/sub 20/, and GA/sub 29/. However, insufficient material was present for unequivocal identification of the metabolites. The radioactive profiles from HPLC of extracts of the node treated with ent-(/sup 3/H)kaurenoic acid were similar for both Na and na plants and contained ent-16..cap alpha..,17-dihydroxykaurenoic acid and ent-6..cap alpha..,7..cap alpha..,16..beta..,17-tetrahydroxykaurenoic acid (both characterized by GC-MS), suggesting that the metabolites arose from side branches of the main GA-biosynthetic pathway. Thus, both Na and na plants appear capable of ent-7..cap alpha..-hydroxylation.

  17. Perspectives of millimeter-wave collective Thomson scattering of confined alphas in ignited plasmas

    SciTech Connect

    Tartari, U.; Nowak, S.; Ramponi, G.

    1996-11-01

    Collective Thomson scattering on alpha density fluctuations in ignited plasma regimes is investigated with reference to a promising candidate source as the mm-wave gyrotron and a representative ITER-like plasma regime. It is shown that a number of intrinsic limitations characterize each of the equatorial scattering geometries selected as more promising, namely a backscattering geometry at {ital f}{sub 0}=80 GHz and two similar quasiorthogonal geometries at {ital f}{sub 0}=180 GHz. A lack of spatial resolution typical of the former geometry has to be contrasted with a significant limitation in plasma access typical of the remaining geometries. Other relevant differences concern the requirements in terms of gyrotron power, acceptable stray radiation levels, etc. Special emphasis is given in the work to a discussion of ECE noise, on which the feasibility itself of the alpha collective scattering diagnostics at mm-waves largely depends in the plasma regimes considered. {copyright} {ital 1996 American Institute of Physics.}

  18. Design of a Collective CO2 Scattering Measurement of Fusion Alphas on TFTR

    NASA Astrophysics Data System (ADS)

    Richards, R.; Hutchinson, D.; Bretz, N.

    1996-11-01

    A design study is presented for a collective CO2 Thomson scattering measurement of confined fusion alphas in high power, deuterium-tritium plasmas in TFTR. The collective regime for these plasmas (n_e=1.0x10^20 m-3, Te = 10 keV, Ti = 35 keV, nD = n_T, n_α/ne = 0.2%) requires scattering angles of about 0.5 deg (kλD = 0.5), resolution lengths along the beam of about 0.4 m, and access windows of 0.1 m diameter. A few spatial resolution elements in the alpha profile are possible. We assume a 50 MW, 1 μs, 30 pps laser and heterodyne detection with PN ~ 5x10-20 W/Hz resolving the alpha ion feature with Δ f ~ 2 GHz(Δ θ/θ = Δ v_α/v_α ~ 0.2). We estimate the maximum signal-to-noise per pulse of about 10 at 5 GHz for an equilibrium alpha slowing down spectrum. Detection is simplified with quantum well detectors which have a bandwidth of 30 GHz permitting double sideband detection and with the use of a hot CO2 gas absorption cell to eliminate the unscattered laser light from the detection. At 10 μm plasma light, refraction, and Faraday rotation are unimportant. Magnetic effects modify the spectrum only for k \\cdot B / kB < 0.1 and can be avoided. Estimates for TFTR are similar to those for ITER where the radial resolution can be better than 0.3 m across the full diameter of 5.8 m.

  19. Analysis of particulates for very light elements by forward scattering of alpha particles

    SciTech Connect

    Wolfe, G.W.

    1980-09-01

    PIXE analysis is limited to elements heavier than sodium. A technique has been developed for obtaining quantitative information about the levels of elements hydrogen through flourine by forward scattering of 18 MeV alphas, and may be obtained simultaneously with PIXE. Using substrate thicknesses less than 1 mg/cm/sup 2/, sensitivities from 2.7 ..mu..g/cm/sup 2/ for hydrogen to 124 ..mu..g/cm/sup 2/ for carbon, may be obtained after corrections, with determinations accurate to +- 15%, in 200 second irradiation times. Substantial corrections must be made.

  20. Solar wind latitude variations and multiple scattering from Galileo interplanetary Lyman-alpha observations

    NASA Technical Reports Server (NTRS)

    Ajello, Joseph M.; Pryor, Wayne R.; Barth, Charles A.; Hord, Charles W.; Simmons, Karen E.

    1993-01-01

    The Galileo Ultraviolet Spectrometer Experiment (UVS) obtained a map of the celestial sphere from interplanetary Lyman-alpha (IPLA) on 13, 14 December 1990 during the Earth1 encounter. The Galileo spacecraft was near the downwind interstellar axis during the encounter and the map view directions filled the downwind hemisphere. The ratio between the observation and a single scattering model is attributed to a direct measurement of the multiple scattering correction required to model IPLA in the inner solar system. Analysis of this data set, referred to as an antisun map, shows that the solar wind charge exchange rate with interplanetary gas is 25 percent less over the solar poles than in the ecliptic at solar maximum. A model of the interstellar wind based on the antisun map observation exhibits a number density of atomic hydrogen far from the solar system, inside the heliosphere, of 0.16 +/- 0.05/cu cm.

  1. Combined molecular dynamics and neutron scattering study of alpha-lactalbumin

    NASA Astrophysics Data System (ADS)

    Tarek, M.; Neumann, D. A.; Tobias, D. J.

    2002-03-01

    Molecular dynamics simulations and quasielastic neutron scattering have been used to elucidate differences in the dynamics of the native state and the partially folded, molten globule state of the protein, alpha-lactalbumin in solution. The neutron results, which are dominated by scattering from non-labile protons, demonstrate that the side-chains in the molten globules are significantly more mobile than those in the native protein. Molecular dynamics results, which reproduce the measured quasielastic neutron spectra extremely well, show that the observed dynamic changes arise primarily from the particular region of the protein that forms a beta sheet in the native state and unfolds to a random coil in the molten globule. Thus the spectroscopic results clearly reflect the formation of secondary structures that occurs as a protein folds.

  2. Structure-function relationships in the Na,K-ATPase. cap alpha. subunit: site-directed mutagenesis of glutamine-111 to arginine and asparagine-122 to aspartic acid generates a ouabain-resistant enzyme

    SciTech Connect

    Price, E.M.; Lingrel, J.B.

    1988-11-01

    Na,K-ATPases from various species differ greatly in their sensitivity to cardiac glycosides such as ouabain. The sheep and human enzymes are a thousand times more sensitive than the corresponding ones from rat and mouse. To define the region of the ..cap alpha..1 subunit responsible for this differential sensitivity, chimeric cDNAs of sheep and rat were constructed and expressed in ouabain-sensitive HeLa cells. The construct containing the amino-terminal half of the rat ..cap alpha..1 subunit coding region and carboxyl-terminal half of the sheep conferred the ouabain-resistant phenotype to HeLa cells while the reverse construct did not. This indicates that the determinants involved in ouabain sensitivity are located in the amino-terminal half of the Na,K-ATPase ..cap alpha.. subunit. By use of site-directed mutagenesis, the amino acid sequence of the first extracellular domain (H1-H2) of the sheep ..cap alpha..1 subunit was changed to that of the rat. When expressed in HeLa cells, this mutated sheep ..cap alpha..1 construct, like the rat/sheep chimera, was able to confer ouabain resistance to these cells. Furthermore, similar results were observed when HeLa cells were transfected with a sheep ..cap alpha..1 cDNA containing only two amino acid substitutions. The resistant cells, whether transfected with the rat ..cap alpha..1 cDNA, the rat/sheep chimera, or the mutant sheep ..cap alpha..1 cDNAs, exhibited identical biochemical characteristics including ouabain-inhibitable cell growth, /sup 86/Rb/sup +/ uptake, and Na,K-ATPase activity. These results demonstrate that the presence of arginine and aspartic acid on the amino end and carboxyl end, respectively, of the H1-H2 extracellular domain of the Na,K-ATPase ..cap alpha.. subunit together is responsible for the ouabain-resistant character of the rat enzyme and the corresponding residues in the sheep ..cap alpha..1 subunit (glutamine and asparagine) are somehow involved in ouabain binding.

  3. Quaternary structure of alpha-crustacyanin from lobster as seen by small-angle X-ray scattering.

    PubMed

    Dellisanti, Cosma D; Spinelli, Silvia; Cambillau, Christian; Findlay, John B C; Zagalsky, Peter F; Finet, Stéphanie; Receveur-Bréchot, Véronique

    2003-06-01

    The structure of alpha-crustacyanin, the blue carotenoprotein of lobster (Homarus gammarus) carapace, has been investigated for the first time using small-angle X-ray scattering. In this paper, we have determined the dimensions of this protein composed of eight heterodimeric subunits of beta-crustacyanin. Analysis of the scattering spectra and estimation of the shape of alpha-crustacyanin show that the protein fits into a cylinder with an axial length of 238 A and a radius of 47.5 A, in which the eight beta-crustacyanin molecules are probably arranged in a helical manner. PMID:12782314

  4. Optical Model Potential Parameters for p, d, {sup 3}He and Alpha-Particle Scattering on Lithium Nuclei

    SciTech Connect

    Burtebayev, N.; Nassurlla, Marzhan; Nassurlla, Maulen; Kerimkulov, Zh. K.; Sakuta, S. B.

    2008-11-11

    Analysis of the p, d, {sup 3}He and {alpha}-particles elastic scattering on the {sup 6}Li and {sup 7}Li nuclei has been done in the framework of the optical model at the beam energies up to 72 MeV. It was shown that the account of the cluster exchange mechanism together with the potential scattering allow reproducing the experimental cross-sections in the whole angular range.

  5. CArG boxes in the human cardiac. cap alpha. -actin gene are core binding sites for positive trans-acting regulatory factors

    SciTech Connect

    Miwa, T.; Boxer, L.M.; Kedes, L.

    1987-10-01

    Positively acting, rate-limiting regulatory factors that influence tissue-specific expression of the human cardiac ..cap alpha..-actin gene in a mouse muscle cell line are shown by in vivo competition and gel mobility-shift assays to bind to upstream regions of its promoter but to neither vector DNA not a ..beta..-globin promoter. Although the two binding regions are distinctly separated, each corresponds to a cis region required for muscle-specific transcriptional stimulation, and each contains a core CC(A+T-rich)/sub 6/GC sequence (designated CArG box), which is found in the promoter regions of several muscle-associated genes. Each site has an apparently different binding affinity for trans-acting factors, which may explain the different transcriptional stimulation activities of the two cis regions. Therefore, the authors conclude that the two CArG box regions are responsible for muscle-specific transcriptional activity of the cardiac ..cap alpha..-actin gene through a mechanism that involves their binding of a positive trans-acting factor in muscle cells.

  6. /sup 45/Ca efflux for myometrial cells: comparison of the effects of prostaglandin F/sub 2/. cap alpha. (PGF/sub 2/), oxytocin (OT) and arachidonate (A)

    SciTech Connect

    Katona, G.; Molnar, M.; Toth, M.; Hertelendy, F.

    1986-03-01

    The aim of this study was to measure PGF/sub 2..cap alpha../-induced Ca/sup 2 +/ release from uterine cells and to compare this to the actions of OT and A. Smooth muscle cells isolated from the uterus (shell gland) of laying hens were cultured for 7 days in M199 plus 10% fetal calf serum. The cells were treated with digitonin (20..mu..M) and preloaded with /sup 45/Ca for 40 min. Addition of PGF/sub 2..cap alpha../ caused a biphasic /sup 45/Ca-efflux. There was a small but significant /sup 45/Ca-release within 30 sec (rapid phase) followed by a larger one within 7 min (slow phase). In comparison, both OT and A stimulated /sup 45/Ca efflux during a single, slow phase. The maximal effect of A was observed at < 7 min, whereas that of OT was slower, peaking after 7 min. Mepacrin, an inhibitor of A release, attenuated the action of OT without having any effect on A promoted /sup 45/Ca-efflux. Indomethacin, an inhibitor of PG synthase, failed to suppress the Ca-releasing effect of A suggesting the A itself or a lipoxygenase product may have been responsible for the observed effects. Moreover, these results provide suggestive evidence that A release is an important step in the action of various uterotonic agents converging on the mobilization of intracellular Ca.

  7. Elastic deuteron scattering on {sup 12}C and {sup 16}O nuclei in the alpha-cluster model

    SciTech Connect

    Berezhnoy, Yu. A.; Mikhailyuk, V. P.; Pilipenko, V. V. Fedorchenko, D. V.

    2013-07-15

    On the basis of the dispersive alpha-cluster model for target nuclei and the theory of multiple diffractive scattering, differential cross sections and analyzing powers for the elastic scattering of 400 and 700-MeV deuterons on {sup 12}C and {sup 16}O target nuclei were calculated in the pointlike-deuteron approximation. In these calculations, the amplitude for incident-deuteron scattering on nuclei was constructed with the aid of amplitudes for d{alpha} scattering that were obtained from a fit to data on d{sup 16}O scattering. The same features were calculated on the basis of the diffraction approximation with allowance for the internal deuteron structure by using the amplitudes obtained earlier for nucleon scattering on {sup 12}C and {sup 16}O nuclei within the same dispersive alpha-clustermodel. The latter made it possible to perform calculations without employing adjustable parameters. The observables calculated on the basis of either approach agree with available experimental data.

  8. Reduction of. cap alpha. ,. beta. -unsaturated nitro compounds with boron hydrides: a new route to N-substituted hydroxylamines

    SciTech Connect

    Mourad, M.S.; Varma, R.S.; Kabalka, G.W.

    1985-01-11

    Sodium borohydride has been used to catalyze the reaction of borane complexes with alpha, beta-unsaturated nitroalkenes. The high purity hydroxylamines are readily isolated in high yield after hydrolysis. 12 references, 2 tables.

  9. Plasmonic coupling of SiO{sub 2}-Ag 'post-cap' nanostructures and silver film for surface enhanced Raman scattering

    SciTech Connect

    Wu, Hsin-Yu; Cunningham, Brian T.

    2011-04-11

    We demonstrate a surface enhanced Raman scattering (SERS) substrate consisting of SiO{sub 2}-Ag''post-cap'' nanostructures with an underlying silver film fabricated by the glancing angle deposition technique. Electromagnetic simulations predict that SERS enhancement is strongly polarization-dependent, consistent with experimental measurements. Optimized coupling between Ag cap nanoparticles and the underlying silver film can be achieved by controlling the thickness of SiO{sub 2} post sandwiched between them to significantly enhance local electric-field intensity and to increase the density of electromagnetic hot spots. A maximum SERS enhancement factor of 2.38x10{sup 9} within the hot spot region is demonstrated, providing sufficient sensitivity for many important applications.

  10. (I-125) 17. cap alpha. -Iodovinyl 11. beta. -methoxyestradiol: in vivo and in vitro properties of a high-affinity estrogen-receptor radiopharmaceutical

    SciTech Connect

    Jagoda, E.M.; Gibson, R.E.; Goodgold, H.; Ferreira, N.; Francis, B.E.; Reba, R.C.; Rzeszotarski, W.J.; Eckelman, W.C.

    1984-04-01

    17 ..cap alpha..-(/sup 125/I)Iodovinyl 11 ..beta..-methoxyestradiol ((I-125)MIVE/sub 2/) has been prepared with high specific activity (155-2000 Ci/mmol) and a high affinity for the estrogen receptor. In vivo distribution studies using immature rats result in high levels of activity in the uterus (20-30% dose/g) with uterus-to-plasma ratios on the order of 68 to 100. Peak activity in the uterus is obtained between 2 and 4 hr, and by 6 hr 50% of the activity has washed out. The radioactive labeling of MIVE/sub 2/ is sufficiently rapid so that (I-123)MIVE/sub 2/ has been synthesized and is currently in clinical trials. These results suggest that MIVE/sub 2/ would be an excellent agent for the study of estrogen receptors in vivo and in vitro.

  11. Amide proton exchange in the. cap alpha. -amylase polypeptide inhibitor tendamistat studied by two-dimensional /sup 1/H nuclear magnetic resonance

    SciTech Connect

    Wang, O.; Kline, A.D.; Wuethrich, K.

    1987-10-06

    The individual amide proton exchange rates in Tendamistat at pH 3.0 and 50/sup 0/C were measured by using two-dimensional ..cap alpha..H nuclear magnetic resonance. Overall, it was found that the distribution of exchange rates along the sequence is dominated by the interstrand hydrogen bonds of the ..beta..-sheet structures. The slowly exchanging protons in the core of the two ..beta..-sheets were shown to exchange via an EX2 mechanism. Further analysis of the data indicates that different large-scale structure fluctuations are responsible for the exchange from the two ..beta..-sheets, even though the three-dimensional structure of Tendamistat appears to consist of a single structural domain.

  12. Role of a guanine nucleotide-binding protein in. cap alpha. /sub 1/-adrenergic receptor-mediated Ca/sup 2 +/ mobilization in DDT/sub 1/ MF-2 cells

    SciTech Connect

    Cornett, L.E.; Norris, J.S.

    1987-11-01

    In this study the mechanisms involved in ..cap alpha../sub 1/-adrenergic receptor-mediated Ca/sup 2 +/ mobilization at the level of the plasma membrane were investigated. Stimulation of /sup 45/Ca/sup 2 +/ efflux from saponin-permeabilized DDT/sub 1/ MF-2 cells was observed with the addition of either the ..cap alpha../sub 1/-adrenergic agonist phenylephrine and guanosine-5'-triphosphate or the nonhydrolyzable guanine nucleotide guanylyl-imidodiphosphate. In the presence of (/sup 32/P) NAD, pertussis toxin was found to catalyze ADP-ribosylation of a M/sub r/ = 40,500 (n = 8) peptide in membranes prepared from DDT/sub 1/, MF-2 cells, possibly the ..cap alpha..-subunit of N/sub i/. However, stimulation of unidirectional /sup 45/Ca/sup 2 +/ efflux by phenylephrine was not affected by previous treatment of cells with 100 ng/ml pertussis toxin. These data suggest that the putative guanine nucleotide-binding protein which couples the ..cap alpha../sub 1/-adrenergic receptor to Ca/sup 2 +/ mobilization in DDT/sub 1/ MF-2 cells is not a pertussis toxin substrate and may possibly be an additional member of guanine nucleotide binding protein family.

  13. Observations of interplanetary Lyman-alpha with the Galileo Ultraviolet Spectrometer: Multiple scattering effects at solar maximum

    NASA Technical Reports Server (NTRS)

    Ajello, J. M.; Pryor, W. R.; Barth, C. A.; Hord, C. W.; Stewart, A. I. F.; Simmons, K. E.; Hall, D. T.

    1994-01-01

    The Galileo Ultravilet Spectrometer Experiment (UVS) obtained a partial celestial sphere map of interplanetary Lyman-alpha (IP L alpha) on 13-14 December 1990 during the first Earth encounter. The Galileo spacecraft was near the downwind axis of the local interstellar medium flow. These UVS measurements sampled the downwind, anti-sunward hemisphere. The data were modeled using a hot model of the interplanetary hydrogen density distribution with the goal of studying multiple scattering effects in the inner solar system. The derived ratio in the downwind direction of the observed brightness and a single scattering model brightness, both normalized to unity in the upwind direction, is 1.82 +/- 0.2. This brightness ratio requires a multiple scattering correction which is 36% larger than can be accounted for by theoretical calculations. The hot model may require: (1) a temperature perturbation of the interstellar wind velocity distribution or (2) an additional downstream source of interplanetary hydrogen. However, a more likely exlanation which affects the hot model is the latitude dependence of the radiation pressure. This dependence, based on the known solar L alpha flux latitude variation at solar maximum, causes a downwind brightness enhancement by preferential focusing of H-atoms with trajectory planes containing the solar poles. This result implies that radiation pressure near the solar poles is nearly independent of solar cycle and is insufficient to lead to a net repulsion of hydrogen atoms by the sun, as can occur near the ecliptic plane during the solar maximum. In addition, the UVS performed 13 observations of IP L alpha while in cruise between Venus and the Earth in 3 directions fixed in ecliptic coordinates.

  14. Use of antibodies specific to defined regions of scorpion. cap alpha. -toxin to study its interaction with its receptor site on the sodium channel

    SciTech Connect

    Ayeb, M.E.; Bahraoui, E.M.; Granier, C.; Rochat, H.

    1986-10-21

    Five antibody populations selected by immunoaffinity chromatography for the specificity toward various regions of toxin II of the scorpion Androctonus australis Hector were used to probe the interaction of this protein with its receptor site on the sodium channel. These studies indicate that two antigenic sites, one located around the disulfide bridge 12-63 and one encompassing residues 50-59, are involved in the molecular mechanisms of toxicity neutralization. Fab fragments specific to the region around disulfide bridge 12-63 inhibit binding of the /sup 125/I-labeled toxin to its receptor site. Also, these two antigenic regions are inaccessible to the antibodies when the toxin is bound to its receptor site. In contrast, the two other antigenic sites encompassing the only ..cap alpha..-helix region (residues 23-32) and a ..beta..-turn structure (residues 32-35) are accessible to the respective antibodies when the toxin is bound to its receptor. Together, these data support the recent proposal that a region made of residues that are conserved in the scorpion toxin family is involved in the binding of the toxin to the receptor.

  15. Solvent effects on the synthesis of ion-exchange membranes by radiation-induced graft polymerization of methyl. cap alpha. ,. beta. ,. beta. -trifluoroacrylate. [Freon 113

    SciTech Connect

    Omichi, H.; Okamoto, J.

    1982-06-01

    Methyl ..cap alpha..,..beta..,..beta..-trifluoroacrylate (MTFA) was grafted onto polyethylene (PE) film and fluorine-containing films to make ion-exchange membranes. In the case of PE the grafting yield was not influenced by the presence of trifluorotrichloroethane (Freon 113) in the reaction mixture, while the presence of methanol decreased the grafting yield. The transversal distribution of graft chains in the film observed by electron-probe x-ray microanalysis showed that when the grafting was carried out in the presence of Freon the amount of graft chains in the central part of PE film was much larger than that at the film surface and that the grafts obtained in the absence of Freon were located mainly at the film surface. The electric resistance of the graft PE film obtained in the presence of Freon decreased more than that of the one obtained in the absence of Freon. The weight loss of the graft films in H/sub 2/O/sub 2/ solution was negligibly small.

  16. 16. cap alpha. -(/sup 77/Br)bromoestradiol-17. beta. : a high specific-activity, gamma-emitting tracer with uptake in rat uterus and induced mammary tumors

    SciTech Connect

    Katzenellenbogen, J.A.; Senderoff, S.G.; McElvany, K.D.; O'Brien, H.A. Jr.; Welch, M.J.

    1981-01-01

    16..cap alpha..-(/sup 77/Br)bromoestradiol-17..beta.. (compound 1) has been synthesized by radiobromination of estrone enoldiacetate. Tissue uptake studies performed 1 hr after administration of compound 1 to immature or mature female rats showed uterus-to-blood ratios of 13, with nontarget tissue-to-blood ratios ranging from 0.6 to 2. Co-administration of unlabeled estradiol caused a selective depression in the uterine uptake with no effect on nontarget tissue uptake. In adult animals bearing adenocarcinomas induced by DMBA (7,12-dimethylbenz(a)anthracene), tumor-to-blood ratios of 6.3 were obtained, this uptake also being depressed in animals treated with unlabeled estradiol. The studies demonstrate that compound 1 has suitable binding properties and sufficiently high specific activity so that its uptake in estrogen target tissues in vivo is mediated primarily by the estrogen receptor. Furthermore, they suggest that this compound may be suitable for imaging human breast tumors that contain estrogen receptors.

  17. Mutations in a gene encoding the. cap alpha. subunit of a Saccharomyces cerevisiae G protein indicate a role in mating pheromone signaling

    SciTech Connect

    Jahng, K.Y.; Ferguson, J.; Reed, S.I.

    1988-06-01

    Mutations which allowed conjugation by Saccharomyces cerevisiae cells lacking a mating pheromone receptor gene were selected. One of the genes defined by such mutations was isolated from a yeast genomic library by complementation of a temperature-sensitive mutation and is identically to the gene GPA1 (also known as SCG1), recently shown to be highly homologous to gene encoding the ..cap alpha.. subunits of mammalian G proteins. Physiological analysis of temperature-sensitive gpal mutations suggests that the encoded G protein is involved in signaling in response to mating pheromones. Mutational disruption of G-protein activity causes cell-cycle arrest in G/sub 1/, deposition of mating-specific cell surface aggultinins, and induction of pheromone-specific mRNa, all of which are responses to pheromone in wild-type cells. In addition, mutants can conjugate without the benefit of mating pheromone or pheromone receptor. A model is presented where the activated G protein has a negative impact on a constitutive signal which normally keeps the pheromone response repressed.

  18. Remarks concerning the O(Z. cap alpha. /sup 2/) corrections to Fermi decays, conserved-vector-current predictions, and universality

    SciTech Connect

    Sirlin, A.

    1987-06-01

    Finite-nuclear-size contributions to the O(Z..cap alpha../sup 2/) corrections to Fermi decays are studied for realistic nuclear-charge distributions. In conjunction with the results of Koslowsky et al. and recent papers by the author and Zucchini and by Jaus and Rasche, these refinements lead to an average value scrFt = 3070.6 +- 1.6 s for the accurately measured superallowed Fermi transitions. Correspondingly, V/sub u//sub d/ = 0.9744 +- 0.0010 and V/sub u//sub d/ /sup 2/+V/sub us/ /sup 2/+V/sub ub/ /sup 2/ = 0.9979 +- 0.0021 in good agreement with the three-generation standard model at the level of its quantum corrections. The agreement with conserved-vector-current predictions is very good, with each of the eight transitions differing from the average by <1sigma. The consequences of using two other calculations of the nuclear mismatch correction delta/sub c/, Wilkinson's microscopic analysis and the recent results of Ormand and Brown, are briefly discussed. A useful upper bound on scrFt, independent of the delta/sub c/ calculation, is given.

  19. Benchmark and combined velocity-space tomography of fast-ion D-alpha spectroscopy and collective Thomson scattering measurements

    NASA Astrophysics Data System (ADS)

    Jacobsen, A. S.; Salewski, M.; Geiger, B.; Korsholm, S. B.; Leipold, F.; Nielsen, S. K.; Rasmussen, J.; Stejner, M.; Weiland, M.; the ASDEX Upgrade Team

    2016-04-01

    We demonstrate the combination of fast-ion D-alpha spectroscopy (FIDA) and collective Thomson scattering (CTS) measurements to determine a common best estimate of the fast-ion velocity distribution function by velocity-space tomography. We further demonstrate a benchmark of FIDA tomography and CTS measurements without using a numerical simulation as common reference. Combined velocity-space tomographies from FIDA and CTS measurements confirm that sawtooth crashes reduce the fast-ion phase-space densities in the plasma center and affect ions with pitches close to one more strongly than those with pitches close to zero.

  20. Experimental determination of the kerma factors for the reaction /sup 12/C(n,n'3. cap alpha. ) at E/sub n/ = 10-35 MeV

    SciTech Connect

    Antolkovic, B.; Slaus, I.; Plenkovic, D.

    1984-02-01

    Kerma factors for the reaction /sup 12/C(n,n'3..cap alpha..) have been experimentally determined performing kinematically complete measurement and using a continuous energy neutron beam up to 35 MeV. The results are compared with only one existing experiment at E/sub n/ = 27.4, 39.7, and 60.7 MeV and with a number of various model calculations.

  1. Mapping of the nucleotide-binding sites in the ADP/ATP carrier of beef heart mitochondria by photolabeling with 2-azido(. cap alpha. -/sup 32/P)adenosine diphosphate

    SciTech Connect

    Dalbon, P.; Brandolin, G.; Boulay, F.; Hoppe, J.; Vignais, P.V.

    1988-07-12

    2-Azido(..cap alpha..-/sup 32/P)adenosine diphosphate (2-azido(..cap alpha..-/sup 32/P)ADP) has been used to photolabel the ADP/ATP carrier in beef heart mitochondria. In reversible binding assays carried out in the dark, this photoprobe was found to inhibit ADP/ATP transport in beef heart mitochondria and to bind to two types of specific sites of the ADP/ATP carrier characterized by high-affinity binding (K/sub d/ = 20 ..mu..M) and low-affinity binding (K/sub d/ = 400 ..mu..M). In contrast, it was unable to bind to specific carrier sites in inverted submitochondrial particles. Upon photoirradiation of beef heart mitochondria in the presence of 2-azido(..cap alpha..-/sup 32/P)ADP, the ADP/ATP carrier was covalently labeled. After purification, the photolabeled carrier protein was cleaved chemically by acidolysis or cyanogen bromide and enzymatically with the Staphylococcus aureus V8 protease. In the ADP/ATP carrier protein, which is 297 amino acid residues in length, two discrete regions extending from Phe-153 to Met-200 and from Tyr-250 to Met-281 were labeled by 2-azido(..cap alpha..-/sup 32/P)ADP. The peptide fragments corresponding to these regions were sequenced, and the labeled amino acids were identified. As 2-azido-ADP is not transported into mitochondria and competes against transport of externally added ADP, it is concluded that the two regions of the carrier which are photolabeled are facing the cytosol. Whether the two photolabeled regions are located in a single peptide chain of the carrier or in different peptide chains of an oligomeric structure is discussed.

  2. Avian serum. cap alpha. /sub 1/-glycoprotein, hemopexin, differing significantly in both amino acid and carbohydrate composition from mammalian (. beta. -glycoprotein) counter parts

    SciTech Connect

    Goldfarb, V.; Trimble, R.B.; Falco, M.D.; Liem, H.H.; Metcalfe, S.A.; Wellner, D.; Muller-Eberhard, U.

    1986-10-21

    The physicochemical characteristics of chicken hemopexin, which can be isolated by heme-agarose affinity chromatography, is compared with representative mammalian hemopexins of rat, rabbit, and human. The avian polypeptide chain appears to be slightly longer (52 kDa) than the human, rat, or rabbit forms (49 kDa), and also the glycoprotein differs from the mammalian hemopexins in being an ..cap alpha../sub 1/-glycoprotein instead of a ..beta../sub 1/-glycoprotein. The distinct electrophoretic mobility probably arises from significant differences in the amino acid composition of the chicken form, which, although lower in serine and particularly in lysine, has a much higher glutamine/glutamate and agrinine content, and also a higher proline, glycine, and histidine content, than the mammalian hemopexins. Compositional analyses and /sup 125/I concanavalin A and /sup 125/I wheat germ agglutinin binding suggest that chicken hemopexin has a mixture of three fucose-free N-linked bi- and triantennary oligosaccharides. In contrast, human hemopexin has give N-linked oligosaccharides and an additional O-linked glycan blocking the N-terminal threonine residue, while the rabbit form has four N-linked oligosaccharides. In keeping with the finding of a simpler carbohydrate structure, the avian hemopexin shows only a single band on polyacrylamide gel electrophoresis under both nondenaturing and denaturing conditions, whereas the hemopexins of the three mammalian species tested show several bands. In contrast, the isoelectric focusing pattern of chicken hemopexin is very complex, revealing at least nine bands between pH 4.0 and pH band 5.0, while the other hemopexins show a broad smear of multiple ill-defined bands in the same region.Results indicate the hemopexin of avians differs substantially from the hemopexins of mammals, which show a notable similarity with regard to carbohydrate structure and amino acid composition.

  3. Effect of. cap alpha. -tocopherol, butylated-hydroxytoluene and hydroxy-anisole on the activation and binding of aflatoxin B/sub 1/ to macromolecules

    SciTech Connect

    Ch'ih, J.J.; Biedrzycka, D.; Devlin, T.M.

    1987-05-01

    The anti-oxidants, ..cap alpha..-tocopherol(TPA), butylated-hydroxy-toluene(BHT) and hydroxyanisole(BHA) inhibit the carcinogenic and toxic effects of a variety of chemical compounds, their effect on aflatoxin B/sub 1/ (AFB/sub 1/) activation and binding was examined utilizing rat liver microsomes and cells. With a NADPH generating system, oxygen, microsomes, (/sup 3/H)-AFB/sub 1/, 2.2 pmoles/h/mg protein was activated and bound to macromolecules. In hepatocytes, 3.4 and 1.4 pmoles of AFB/sub 1/ per 10/sup 6/ cells were taken up and bound to macromolecules, whereas the nucleic acid fraction contained 0.19 pmoles of bound AFB/sub 1/. Moderate decreases of AFB/sub 1/ activation and binding were observed when TPA was present in both cell-free and hepatocytes systems. Only in hepatocytes, BHT inhibited the AFB/sub 1/ uptake and binding to nucleic acids. BHA, however, inhibited microsomal activation of AFB/sub 1/ by 73%; maximum inhibition was reached at 1 mM. AFB/sub 1/ uptake, and binding to nucleic acids were inhibited by 65% and 79% by BHA. GSH-transferase activity of cells treated with these agents was not altered. The effect of BHA at various concentrations on AFB activation was compared with cytochrome P-450 inhibitors; the ED/sub 50/ of SKF 525A, BHA and metyrapone was 9 uM, 80 uM and 380 uM respectively. The data suggest that TPA, BHA and BHT exert their effect by different mechanisms.

  4. Cervical Cap

    MedlinePlus

    ... and remove the cap. How Much Does It Cost? A cervical cap costs about $70 and should be replaced every year. In addition, there is also the cost of the doctor's visit. Many health insurance plans ...

  5. Alpha-catenin-Dependent Recruitment of the Centrosomal Protein CAP350 to Adherens Junctions Allows Epithelial Cells to Acquire a Columnar Shape

    PubMed Central

    Zurbano, Angel; Formstecher, Etienne; Martinez-Morales, Juan R.; Bornens, Michel; Rios, Rosa M.

    2015-01-01

    Epithelial morphogenesis involves a dramatic reorganisation of the microtubule cytoskeleton. How this complex process is controlled at the molecular level is still largely unknown. Here, we report that the centrosomal microtubule (MT)-binding protein CAP350 localises at adherens junctions in epithelial cells. By two-hybrid screening, we identified a direct interaction of CAP350 with the adhesion protein α-catenin that was further confirmed by co-immunoprecipitation experiments. Block of epithelial cadherin (E-cadherin)-mediated cell-cell adhesion or α-catenin depletion prevented CAP350 localisation at cell-cell junctions. Knocking down junction-located CAP350 inhibited the establishment of an apico-basal array of microtubules and impaired the acquisition of columnar shape in Madin-Darby canine kidney II (MDCKII) cells grown as polarised epithelia. Furthermore, MDCKII cystogenesis was also defective in junctional CAP350-depleted cells. CAP350-depleted MDCKII cysts were smaller and contained either multiple lumens or no lumen. Membrane polarity was not affected, but cortical microtubule bundles did not properly form. Our results indicate that CAP350 may act as an adaptor between adherens junctions and microtubules, thus regulating epithelial differentiation and contributing to the definition of cell architecture. We also uncover a central role of α-catenin in global cytoskeleton remodelling, in which it acts not only on actin but also on MT reorganisation during epithelial morphogenesis. PMID:25764135

  6. High-repetition CO{sub 2} laser for collective Thomson scattering diagnostic of {alpha} particles in burning plasmas

    SciTech Connect

    Kondoh, T.; Hayashi, T.; Kawano, Y.; Kusama, Y.; Sugie, T.; Miura, Y.; Koseki, R.; Kawahara, Y.

    2006-10-15

    A high-repetition and high-energy transversely excited atmospheric carbon dioxide (CO{sub 2}) laser for a collective Thomson scattering (CTS) diagnostic has been developed to establish a diagnostic method of confined {alpha} particles in burning plasmas. To excite a single-transverse and single-longitudinal mode, a continuous wave seed laser was injected to an unstable resonator with a cavity length of {approx}4.4 m. Pulse energy of 10 J with a repetition rate of 10 Hz has been achieved in the single-mode operation. Pulse energies of 18 J with a repetition rate of 10 Hz and 36 J with single shot operation have also been achieved in the multimode operation. These results give a prospect for the CTS diagnostic on International Thermonuclear Experimental Reactor (ITER), which requires single-mode energy of 20 J with repetition rate of 40 Hz.

  7. Cobalt Coordination and Clustering in [alpha]-Co(OH)[subscript 2] Revealed by Synchrotron X-ray Total Scattering

    SciTech Connect

    Neilson, James R.; Kurzman, Joshua A.; Seshadri, Ram; Morse, Daniel E.

    2010-09-17

    Structures of layered metal hydroxides are not well described by traditional crystallography. Total scattering from a synthesis-controlled subset of these materials, as described here, reveals that different cobalt coordination polyhedra cluster within each layer on short length scales, offering new insights and approaches for understanding the properties of these and related layered materials. Structures related to that of brucite [Mg(OH){sub 2}] are ubiquitous in the mineral world and offer a variety of useful functions ranging from catalysis and ion-exchange to sequestration and energy transduction, including applications in batteries. However, it has been difficult to resolve the atomic structure of these layered compounds because interlayer disorder disrupts the long-range periodicity necessary for diffraction-based structure determination. For this reason, traditional unit-cell-based descriptions have remained inaccurate. Here we apply, for the first time to such layered hydroxides, synchrotron X-ray total scattering methods - analyzing both the Bragg and diffuse components - to resolve the intralayer structure of three different {alpha}-cobalt hydroxides, revealing the nature and distribution of metal site coordination. The different compounds with incorporated chloride ions have been prepared with kinetic control of hydrolysis to yield different ratios of octahedrally and tetrahedrally coordinated cobalt ions within the layers, as confirmed by total scattering. Real-space analyses indicate local clustering of polyhedra within the layers, manifested in the weighted average of different ordered phases with fixed fractions of tetrahedrally coordinated cobalt sites. These results, hidden from an averaged unit-cell description, reveal new structural characteristics that are essential to understanding the origin of fundamental material properties such as color, anion exchange capacity, and magnetic behavior. Our results also provide further insights into the

  8. Preliminary results from ASP on tests of QED to order. cap alpha. /sup 4/ in e/sup +/e/sup -/ annihilation at. sqrt. s = 29 GeV

    SciTech Connect

    Hawkins, C.A.

    1988-11-01

    Tests of QED to order ..cap alpha../sup 4/ performed with the ASP detector at PEP are presented. Measurements have been made of exclusive e/sup +/e/sup -/e/sup +/e/sup -/, e/sup +/e/sup -/..gamma gamma.. and ..gamma gamma gamma gamma.. final states with all particles above 50 milliradians with respect to the e/sup +/e/sup -/ beam line. These measurements represent a significant increase in statistics over previous measurements. All measurements agree well with theoretical predictions. 5 refs., 1 tab.

  9. Redetermination of the crystal structure of. cap alpha. -Bi/sub 2/O/sub 3/. 3MoO/sub 3/ By neutron diffraction and the catalytic oxidation of propene

    SciTech Connect

    Theobald, F.; Hewat, A.W.; Laarif, A.

    1985-06-01

    The powder profile obtained by neutron diffraction was analysed by the Rietveld method. The catalytic oxidation of propene over ..cap alpha..-Bi/sub 2/O/sub 3/.3MoO/sub 3/ is examined. The high activity is related to the fact that the principal cleavage plane contains together Bi and Mo ions. On the contrary ..gamma..-Bi/sub 2/O/sub 3/.MoO/sub 3/ is less active, probably because only small faces are active. The lone pairs disposition is not favorable to oxygen ionic conductivity; this rather low conductivity may favour a rather high selectivity in acrolein.

  10. Small-angle neutron scattering studies of mineralization on BSA coated citrate capped gold nanoparticles used as a model surface for membrane scaling in RO wastewater desalination.

    PubMed

    Dahdal, Y N; Pipich, V; Rapaport, H; Oren, Y; Kasher, R; Schwahn, D

    2014-12-23

    Bovine serum albumin (BSA) coated on citrate capped gold nanoparticles (BSA-GNPs) was exposed to a simulated wastewater effluent (SSE) in order to study the mineralization and thereby mimic scaling at biofouled membranes of reverse osmosis (RO) wastewater desalination plants. RO is a leading technology of achieving freshwater quality as it has the capability of removing both dissolved inorganic salts and organic contaminants from tertiary wastewater effluents. The aim was to better understand one of the major problems facing this technology which is fouling of the membranes, mainly biofouling and scaling by calcium phosphate. The experiments were performed using the small-angle neutron scattering (SANS) technique. The nanoparticles, GNPs, stabilized by the citrate groups showed 30 Å large particles having a homogeneous distribution of gold and citrate with a gold volume fraction of the order of 1%. On the average two BSA monomers are grafted at 2.4 GNPs. The exposed BSA-GNPs to SSE solution led to immediate mineralization of stable composite particles of the order of 0.2 μm diameter and a mineral volume fraction between 50% and 80%. The volume fraction of the mineral was of the order of 10(-5), which is roughly 3 times larger but an order of magnitude smaller than the maximum possible contents of respectively calcium phosphate and calcium carbonate in the SSE solution. Considering the extreme low solubility product of calcium phosphate, we suggest total calcium phosphate and partially (5-10%) calcium carbonate formation in the presence of BSA-GNPs.

  11. Small-angle neutron scattering studies of mineralization on BSA coated citrate capped gold nanoparticles used as a model surface for membrane scaling in RO wastewater desalination.

    PubMed

    Dahdal, Y N; Pipich, V; Rapaport, H; Oren, Y; Kasher, R; Schwahn, D

    2014-12-23

    Bovine serum albumin (BSA) coated on citrate capped gold nanoparticles (BSA-GNPs) was exposed to a simulated wastewater effluent (SSE) in order to study the mineralization and thereby mimic scaling at biofouled membranes of reverse osmosis (RO) wastewater desalination plants. RO is a leading technology of achieving freshwater quality as it has the capability of removing both dissolved inorganic salts and organic contaminants from tertiary wastewater effluents. The aim was to better understand one of the major problems facing this technology which is fouling of the membranes, mainly biofouling and scaling by calcium phosphate. The experiments were performed using the small-angle neutron scattering (SANS) technique. The nanoparticles, GNPs, stabilized by the citrate groups showed 30 Å large particles having a homogeneous distribution of gold and citrate with a gold volume fraction of the order of 1%. On the average two BSA monomers are grafted at 2.4 GNPs. The exposed BSA-GNPs to SSE solution led to immediate mineralization of stable composite particles of the order of 0.2 μm diameter and a mineral volume fraction between 50% and 80%. The volume fraction of the mineral was of the order of 10(-5), which is roughly 3 times larger but an order of magnitude smaller than the maximum possible contents of respectively calcium phosphate and calcium carbonate in the SSE solution. Considering the extreme low solubility product of calcium phosphate, we suggest total calcium phosphate and partially (5-10%) calcium carbonate formation in the presence of BSA-GNPs. PMID:25458085

  12. Revised alpha4 term of lepton g-2 from the Feynman diagrams containing an internal light-by-light scattering subdiagram.

    PubMed

    Kinoshita, T; Nio, M

    2003-01-17

    The alpha(4) contribution to the lepton g-2 from a gauge-invariant set of 18 Feynman diagrams containing a light-by-light scattering subdiagram internally has been reevaluated by a method independent of the previous approach. Comparison of two methods revealed a program error in the first version. Correcting this error, the contributions of these 18 diagrams become -0.990 72(10)(alpha/pi)(4) and -4.432 43(58)(alpha/pi)(4) for the electron and muon g-2, respectively. The correction is not large enough to affect the comparison between theory and experiment for the muon g-2, but it does alter the inferred value for the fine structure constant alpha(-1) by 6 ppb.

  13. Subunit structure of the dihydrolipoyl transacylase component of branched-chain. cap alpha. -keto acid dehydrogenase complex from bovine liver: mapping of the lipoyl-bearing domain by limited proteolysis

    SciTech Connect

    Not Available

    1986-01-05

    To characterize the lipoyl-bearing domain of the dihydrolipoyl transacylase (E/sub 2/) component, purified branched-chain ..cap alpha..-keto acid dehydrogenase complex from bovine liver was reductively acylated with (U-/sup 14/C)..cap alpha..-ketoisovalerate in the presence of thiamin pyrophosphate and N-ethylmaleimide. Digestion of the modified complex with increasing concentrations of trypsin sequentially cleaved the E/sub 2/ polypeptide chain (M/sub r/ = 52,000) into five radiolabeled lipoyl-containing fragments, L/sub 1/-L/sub 5/. In addition, a lipoate-free inner E/sub 2/ core consisting of fragment A and fragment B was produced. Fragment A contains the active site for transacylation reaction and fragment B is the subunit-binding domain. Fragment L/sub 5/ and fragment B were stable and resistant to further tryptic digestion. Mouse antiserium against E/sub 2/ reacted only with fragments L/sub 1/, L/sub 2/, and L/sub 3/, and did not bind fragments L/sub 4/, L/sub 5/, A, and B as judged by immunoblotting analysis. The anti-E/sub 2/ serum-strongly inhibited the overall reaction catalyzed by the complex, but was without effect on the transacylation activity of E/sub 2/. Measurement of incorporation of (1-/sup 14/C)isobutyryl groups into the E/sub 2/ subunit indicated the presence of 1 lipoyl residue/E/sub 2/ chain.

  14. Cradle cap

    MedlinePlus

    ... be prescribed. These may include medicated creams or shampoos. Most cases of cradle cap can be managed ... improve scalp circulation. Give your child daily, gentle shampoos with a mild shampoo as long as there ...

  15. Synthesis of tritium labeled Ac-(Nle/sup 4/, D-Phe/sup 7/)-. cap alpha. -MSH/sub 4-11/-NH/sub 2/: a superpotent melanotropin with prolonged biological activity

    SciTech Connect

    Wilkes, B.D.; Hruby, V.J.; Yamamura, H.I.; Akiyama, K.; Castrucci, A.M. de; Hadley, M.E.; Andrews, J.R.; Wan, Y.P.

    1984-03-05

    Ac-(Nle/sup 4/, D-Phe/sup 7/)-..cap alpha..-MSH/sub 4-11/-NH/sub 2/ an octapeptide, is a melanotropin analogue (Ac-Nle-Glu-His-D-Phe-Arg-Trp-Gly-Lys-NH/sub 2/), which is a superpotent agonist of frog and lizard skin melanocytes and mouse S 91 (Cloudman) melanoma cells. This melanotropin possesses ultraprolonged activity on melanocytes, both in vitro and in vivo, and the peptide is resistant to inactivation by serum enzymes. The tritium-labeled congener was prepared by direct incorporation of (/sup 3/H)-labeled norleucine into the peptide. The melanotropic activity of the labeled peptide is identical to the unlabeled analogue. This labeled peptide should be useful for studies on the localization and characterization of melanotropin receptors.

  16. Cytochrome P450c17 (steroid 17. cap alpha. -hydroxylase/17,20 lyase): cloning of human adrenal and testis cDNAs indicates the same gene is expressed in both tissues

    SciTech Connect

    Chung, B.; Picado-Leonard, J.; Haniu, M.; Bienkowski, M.; Hall, P.F.; Shively, J.E.; Miller, W.L.

    1987-01-01

    P450c17 is the single enzyme mediating both 17..cap alpha..-hydroxylase (steroid 17..cap alpha..-monooxygenase, EC 1.14.99.9) and 17,20 lyase activities in the synthesis of steroid hormones. It has been suggested that different P450c17 isozymes mediate these activities in the adrenal gland and testis. The authors sequenced 423 of the 509 amino acids (83%) of the porcine adrenal enzyme; based on this partial sequence, a 128-fold degenerate 17-mer was synthesized and used to screen a porcine adrenal cDNA library. This yielded a 380-base cloned cDNA, which in turn was used to isolate several human adrenal cDNAs. The longest of these, lambda hac 17-2, is 1754 base pairs long and includes the full-length coding region, the complete 3'-untranslated region, and 41 bases of the 5'-untranslated region. This cDNA encodes a protein of 508 amino acids having a predicted molecular weight of 57,379.82. High-stringency screening of a human testicular cDNA library yielded a partial clone containing 1303 identical bases. RNA gel blots and nuclease S1-protection experiments confirm that the adrenal and testicular P450c17 mRNAs are indistinguishable. These data indicate that the testis possesses a P450c17 identical to that in the adrenal. The human amino acid sequence is 66.7% homologous to the corresponding regions of the porcine sequence, and the human cDNA and amino acid sequences are 80.1 and 70.3% homologous, respectively, to bovine adrenal P450c17 cDNA. Both comparisons indicate that a central region comprising amino acid residues 160-268 is hypervariable among these species of P450c17.

  17. On capturing the grain-scale elastic and plastic anisotropy of alpha-Ti with spherical nanoindentation and electron back-scattered diffraction

    DOE PAGESBeta

    Weaver, Jordan S.; Priddy, Matthew W.; McDowell, David L.; Kalidindi, Surya R.

    2016-07-10

    Here, spherical nanoindentation combined with electron back-scattered diffraction has been employed to characterize the grain-scale elastic and plastic anisotropy of single crystal alpha-Ti of two different compositions (in two different titanium alloys). Data analyses protocols needed to reliably extract the desired properties of interest are extended and demonstrated in this paper. Specifically, the grain-scale mechanical response is extracted in the form of indentation stress-strain curves for commercially pure (CP-Ti) alpha-Ti and alloyed (Ti-64) titanium from measurements on polycrystalline samples. The results are compared with responses of single crystals and nanoindentation tests (hardness and modulus) from the literature, and the measuredmore » indentation moduli are validated using crystal-elastic finite element simulations. The results obtained in this study show that (i) it is possible to characterize reliably the elastic and plastic anisotropy of alpha-Ti (hcp) of varying alloying contents with spherical nanoindentation stress-strain curves, (ii) the indentation modulus of alpha-Ti-64 is 5–10% less than CP-Ti, and (iii) the indentation yield strength of alpha-Ti-64 is 50–80% higher than CP-Ti.« less

  18. ITER Plasma at Ion Cyclotron Frequency Domain: The Fusion Alpha Particles Diagnostics Based on the Stimulated Raman Scattering of Fast Magnetosonic Wave off High Harmonic Ion Bernstein Modes

    NASA Astrophysics Data System (ADS)

    Stefan, V. Alexander

    2014-10-01

    A novel method for alpha particle diagnostics is proposed. The theory of stimulated Raman scattering, SRS, of the fast wave and ion Bernstein mode, IBM, turbulence in multi-ion species plasmas, (Stefan University Press, La Jolla, CA, 2008). is utilized for the diagnostics of fast ions, (4)He (+2), in ITER plasmas. Nonlinear Landau damping of the IBM on fast ions near the plasma edge leads to the space-time changes in the turbulence level, (inverse alpha particle channeling). The space-time monitoring of the IBM turbulence via the SRS techniques may prove efficient for the real time study of the fast ion velocity distribution function, spatial distribution, and transport. Supported by Nikola Tesla Labs., La Jolla, CA 92037.

  19. Measurement of elastic 12C+alpha scattering: details of the experiment, analysis, and discussion of phase shifts

    SciTech Connect

    Couture, Aaron Joseph; Detwiler, Rebecca; Gorres, Joachim; Stech, Edward J; Ugalde, Claudio; Wiescher, Michael C F; Heil, Michael; Kappeler, Franz; Azuma, Richard E; Buchmann, Lothar

    2009-01-01

    Recent global analyses of {sup 12}C({alpha},{gamma}){sup 16}O have incorporated both elastic-scallering and {beta}-decay data in addition to direct measurements. In that context, it has been shown that an improvement in the available elastic-scallering data could help determine the contribution of the two subthreshold states, 6.92(2{sup +}) and 7.12(1{sup -}) MeV, and with excellent statistics could restrict resonance parameters above the threshold. To this end angular distributions of {sup 12}C({alpha}, {alpha}){sup 12}C in the {alpha}-energy range of 2.6-8.2 MeV, at angles from 24 to 166 have been measured at the University of Notre Dame using an array of 32 silicon detectors. Details of the experiment are reported. In the present analysis, the phase shifts have been determined from our previously reported R-matrix fit to these data. The uncertainties in the R-matrix phase shifts ({ell} = 0...6) are derived by a new Monte Carlo analysis technique as described in the article. We provide these phase shifts here for general use, in particular for the improved analysis and extrapolation of the {alpha} radiative capture to low energies.

  20. How Large is an [alpha]-Helix? Studies of the Radii of Gyration of Helical Peptides by Small-angle X-ray Scattering and Molecular Dynamics

    SciTech Connect

    Zagrovic, Bojan; Jayachandran, Guha; Millett, Ian S.; Doniach, Sebastian; Pande, Vijay S.

    2010-11-30

    Using synchrotron radiation and the small-angle X-ray scattering technique we have measured the radii of gyration of a series of alanine-based alpha-helix-forming peptides of the composition Ace-(AAKAA)(n)-GY-NH(2), n=2-7, in aqueous solvent at 10(+/-1) degrees C. In contrast to other techniques typically used to study alpha-helices in isolation (such as nuclear magnetic resonance and circular dichroism), small-angle X-ray scattering reports on the global structure of a molecule and, as such, provides complementary information to these other, more sequence-local measuring techniques. The radii of gyration that we measure are, except for the 12-mer, lower than the radii of gyration of ideal alpha-helices or helices with frayed ends of the equivalent sequence-length. For example, the measured radius of gyration of the 37-mer is 14.2(+/-0.6)A, which is to be compared with the radius of gyration of an ideal 37-mer alpha-helix of 17.6A. Attempts are made to analyze the origin of this discrepancy in terms of the analytical Zimm-Bragg-Nagai (ZBN) theory, as well as distributed computing explicit solvent molecular dynamics simulations using two variants of the AMBER force-field. The ZBN theory, which treats helices as cylinders connected by random walk segments, predicts markedly larger radii of gyration than those measured. This is true even when the persistence length of the random walk parts is taken to be extremely short (about one residue). Similarly, the molecular dynamics simulations, at the level of sampling available to us, give inaccurate values of the radii of gyration of the molecules (by overestimating them by around 25% for longer peptides) and/or their helical content. We conclude that even at the short sequences examined here (< or =37 amino acid residues), these alpha-helical peptides behave as fluctuating semi-broken rods rather than straight cylinders with frayed ends.

  1. Purification of the labeled cyanogen bromide peptides of the. cap alpha. polypeptide from sodium and potassium ion-activated adenosinetriphosphatase modified with N-(/sup 3/H)ethylmaleimide

    SciTech Connect

    Le, D.T.

    1985-01-01

    Sodium and potassium ion-activated adenosinetriphosphatase, isolated from canine kidney, was reacted with N-(/sup 3/H)ethylmaleimide under three different conditions, defined by particular concentrations of ligands for the enzyme, such that after the same amount of time the remaining activity of then enzyme varied from 90% to 30%. The conformation of the enzyme also differed among the three conditions. In all cases, the ..cap alpha..-polypeptide was purified and subjected to cyanogen bromide digestion. Two distinct, radioactive peptides were separated by gel filtration of the cyanogen bromide digest on a column of Sephadex LH-60 equilibrated with 95% ethanol: 88% formic acid:4:1. One of the radioactive peptides was shown to contain the sulfhydryl residue whose reaction with N-ethylmaleimide inactivates the enzyme. The other radioactive peptide contained a sulfhydryl residue that seems to react with N-ethylmaleimide only when the binding site for ATP is not occupied. Alkylation of this residue, however, does not result in inactivation of enzyme. Both peptides were purified further by high-pressure liquid chromatography, and their amino-terminal sequences were determined by the manual dansyl-Edman or solid-phase techniques. The peptide containing the sulfhydryl protected by ATP has, as its amino terminus, the lysine that reacts exclusively with fluorescein-5'-isothiocyanate.

  2. Onset of the alpha-relaxation in the glass-forming solution LiCl-6H2O revealed by Brillouin scattering techniques.

    PubMed

    Santucci, S C; Comez, L; Scarponi, F; Monaco, G; Verbeni, R; Legrand, J-F; Masciovecchio, C; Gessini, A; Fioretto, D

    2009-10-21

    We measured the dynamic structure factor of the liquid and glassy phases of the LiCl-6H(2)O solution by means of inelastic scattering of radiation in the visible, UV, and x-ray range, between 1 GHz and 10 THz, and by means of photon-correlation spectroscopy, between 0.01 Hz and 20 kHz. The measurements were performed in the temperature range between 353 and 80 K. Our data show that a single-relaxation process exists at high temperature, which has features similar to those of the single relaxation of pure water. Upon cooling the system below approximately 220 K, this single mode starts to differentiate two processes, a structural (alpha-) and a secondary (beta-) relaxation. As the temperature is decreased, the beta-relaxation is the vanishing continuation of the single, high-temperature process, while the onset of the alpha-relaxation occurs at the expense of the beta-process. PMID:20568872

  3. Refinement of the Compton-Rayleigh scatter ratio method for use on the Mars Science Laboratory alpha particle X-ray spectrometer: II - Extraction of invisible element content

    NASA Astrophysics Data System (ADS)

    Perrett, Glynis M.; Campbell, John L.; Gellert, Ralf; King, Penelope L.; Nield, Emily; O'Meara, Joanne M.; Pradler, Irina

    2016-02-01

    The intensity ratio C/R between Compton and Rayleigh scatter peaks of the exciting Pu L X-rays in the alpha particle X-ray spectrometer (APXS) is strongly affected by the presence of very light elements such as oxygen which cannot be detected directly by the APXS. C/R values are determined along with element concentrations by fitting APXS spectra of geochemical reference materials (GRMs) with the GUAPX code. A quantity K is defined as the ratio between the C/R value determined by Monte Carlo simulation based on the measured element concentrations and the fitted C/R value from the spectrum. To ensure optimally accurate K values, the choice of appropriate GRMs is explored in detail, with attention paid to Rb and Sr, whose characteristic Kα X-ray peaks overlap the Pu Lα scatter peaks. The resulting relationship between the ratio K and the overall oxygen fraction is linear. This provides a calibration from which the concentration of additional light invisible constituents (ALICs) such as water may be estimated in unknown rock and conglomerate samples. Several GRMs are used as 'unknowns' in order to evaluate the accuracy of ALIC concentrations derived in this manner.

  4. Modeling the Scattering Polarization of the Hydrogen Ly-alpha Line Observed by CLASP in a Filament Channel

    NASA Technical Reports Server (NTRS)

    Stepan, J.; Trujillo Bueno, J.; Gunar, S.; del Pino Aleman, T.; Heinzel, P.; Kano, R.; Ishikawa, R.; Narukage, M.; Bando, T.; Winebarger, Amy; Kobayashi, K.; Auchere, F.

    2016-01-01

    The 400 arcsec spectrograph slit of CLASP crossed predominantly quiet regions of the solar chromosphere, from the limb towards the solar disk center. Interestingly, in the CLASP slit-jaw images and in the SDO images of the He I line at 304 A, we can identify a filament channel (FC) extending over more than 60 arcsec crossing the spectrograph slit. In order to interpret the peculiar spatial variation of the Q/1 and U/1 signals observed by CLASP in the hydrogen Ly-alpha line (1216 A) and in the Si Ill line (1206 A) in such a filament channel, it is necessary to perform multi-dimensional radiative transfer modeling. In this contribution, we show the first results of the two-dimensional calculations we are carrying out in given filament models, with the aim of determining the filament thermal and magnetic structure by comparing the theoretical and the observed polarization signals.

  5. Cu²⁺ functionalized N-acetyl-L-cysteine capped CdTe quantum dots as a novel resonance Rayleigh scattering probe for the recognition of phenylalanine enantiomers.

    PubMed

    Yang, Jidong; Tan, Xuanping; Zhang, Xiaoning; Yang, Qiong; Shen, Yizhong

    2015-01-01

    A simple protocol that can be used to simultaneously determinate enantiomers is extremely intriguing and useful. In this study, we proposed a low-cost, facile, sensitive method for simultaneous determination. The molecular recognition of Cu(2+) functionalized N-acetyl-l-cysteine capped CdTe quantum dots (Cu(2+)-NALC/CdTe QDs) with phenylalanine (PA) enantiomers was investigated based on the resonance Rayleigh scattering (RRS) spectral technique. The RRS intensity of NALC/CdTe QDs is very weak, but Cu(2+) functionalized NALC/CdTe QDs have extremely high RRS intensity, the most important observations are that PA could quench the RRS intensity of Cu(2+)-NALC/CdTe QDs, and that l-PA and d-PA have different degree of influence. In addition, those experimental factors such as acidity, concentration of Cu(2+) and reaction time were investigated in regards to their effects on enantioselective interaction. Finally, the applicability of the chiral recognized sensor for the analysis of chiral mixtures on enantiomers has been demonstrated, and the results that were obtained high precision (<4.63%) and low error (<3.06%).

  6. A small-angle X-ray scattering study of alpha-synuclein from human red blood cells

    PubMed Central

    Araki, Katsuya; Yagi, Naoto; Nakatani, Rie; Sekiguchi, Hiroshi; So, Masatomo; Yagi, Hisashi; Ohta, Noboru; Nagai, Yoshitaka; Goto, Yuji; Mochizuki, Hideki

    2016-01-01

    α-synuclein (α-syn) is the main component of Lewy bodies, which are neuropathological hallmarks of patients with Parkinson’s disease. As it has been controversial whether human α-syn from erythrocytes exists as a tetramer under physiological conditions, we tried solving this issue by the small-angle X-ray solution scattering method. Under two different conditions (high ionic strength with a Tris buffer and low ionic strength with an ammonium acetate buffer), no evidence was found for the presence of tetramer. When comparing erythrocyte and recombinant α-syn molecules, we found no significant difference of the molecular weight and the secondary structure although the buffer conditions strongly affect the radius of gyration of the protein. The results indicate that, even though a stable tetramer may not be formed, conformation of α-syn depends much on its environment, which may be the reason for its tendency to aggregate in cells. PMID:27469540

  7. A small-angle X-ray scattering study of alpha-synuclein from human red blood cells.

    PubMed

    Araki, Katsuya; Yagi, Naoto; Nakatani, Rie; Sekiguchi, Hiroshi; So, Masatomo; Yagi, Hisashi; Ohta, Noboru; Nagai, Yoshitaka; Goto, Yuji; Mochizuki, Hideki

    2016-01-01

    α-synuclein (α-syn) is the main component of Lewy bodies, which are neuropathological hallmarks of patients with Parkinson's disease. As it has been controversial whether human α-syn from erythrocytes exists as a tetramer under physiological conditions, we tried solving this issue by the small-angle X-ray solution scattering method. Under two different conditions (high ionic strength with a Tris buffer and low ionic strength with an ammonium acetate buffer), no evidence was found for the presence of tetramer. When comparing erythrocyte and recombinant α-syn molecules, we found no significant difference of the molecular weight and the secondary structure although the buffer conditions strongly affect the radius of gyration of the protein. The results indicate that, even though a stable tetramer may not be formed, conformation of α-syn depends much on its environment, which may be the reason for its tendency to aggregate in cells. PMID:27469540

  8. THE SCATTERING POLARIZATION OF THE Ly{alpha} LINES OF H I AND He II TAKING INTO ACCOUNT PARTIAL FREQUENCY REDISTRIBUTION AND J-STATE INTERFERENCE EFFECTS

    SciTech Connect

    Belluzzi, Luca; Trujillo Bueno, Javier; Stepan, Jiri

    2012-08-10

    Recent theoretical investigations have pointed out that the cores of the Ly{alpha} lines of H I and He II should show measurable scattering polarization signals when observing the solar disk, and that the magnetic sensitivity, through the Hanle effect, of such linear polarization signals is suitable for exploring the magnetism of the solar transition region. Such investigations were carried out in the limit of complete frequency redistribution (CRD) and neglecting quantum interference between the two upper J-levels of each line. Here we relax both approximations and show that the joint action of partial frequency redistribution and J-state interference produces much more complex fractional linear polarization (Q/I) profiles, with large amplitudes in their wings. Such wing polarization signals turn out to be very sensitive to the temperature structure of the atmospheric model, so that they can be exploited for constraining the thermal properties of the solar chromosphere. Finally, we show that the approximation of CRD without J-state interference is however suitable for estimating the amplitude of the linear polarization signals in the core of the lines, where the Hanle effect operates.

  9. Peroxidation of the dried thin film of lipid by high-energy alpha particles from a cyclotron

    SciTech Connect

    Agarwal, S.; Chatterjee, S.N.

    1984-11-01

    High-energy ..cap alpha.. particles produced a dose-dependent linear increase in different lipid peroxidation products (e.g., malondialdehyde (MDA), conjugated dienes, and hydroperoxides) in the dried thin film state. An inverse dose-rate effect was observed when the dose rate was varied by changing either the ..cap alpha..-particle fluence rate or the ..cap alpha..-particle energy. The antioxidants ..cap alpha..-tocopherol and butylated hydroxytoluene (BHT) suppressed the ..cap alpha..-particle-induced lipid peroxidation in the dried thin film state, and in this respect ..cap alpha..-tocopherol was found superior to BHT. It was found that ..cap alpha..-tocopherol was equally efficient in inhibiting lipid peroxidations by ..cap alpha.. particles and ultraviolet light.

  10. Thomson scattering as a method for laser plasma diagnostics

    SciTech Connect

    Alayi, Y.

    1983-12-01

    The Thomson scattering has been used to determine the density and temperature of an inhomogeneous nonstationary plasma. A common method to calibrate the Thomson scattering device consists in replacing the plasma by a gas and measuring the Rayleigh scattering cross section. The angular distribution of the scattered light in Argon is measured, the incident light is a ruby laser with ..delta..t = 30ns and lambda = 6943nm and vertically polarized. We have found that angular distribution is strongly favored in the forward direction (30/sup 0/, 45/sup 0/, 60/sup 0/) and defavored for backward direction (90/sup 0/, 120/sup 0/, 135/sup 0/, 150/sup 0/) in agreement with the results of George, et al, but in disagreement with the Rayleigh theory which assumes a uniform distribution. Our results may be related to the form of the scattered light spectrum which undergoes a dramatic change through the kinetic-hydrodynamic transition. The general form of the spectrum is determined by the parameter y = 1/Kl (where K = 4..pi.. sin (theta/2)/lambda, theta is the scattering angle and l is the free path path), which increases in the direction of the hydrodynamic regime (small angles). By analogy, the Thomson scattering presents the same aspects with ..cap alpha.. = 1/Klambda /SUB D/ (where lambda /SUB D/ is the Debye length). The deviation from the uniform distribution provides the possibility to determine the plasma turbulence spectrum from the scattered light.

  11. Vinyl capped addition polyimides

    NASA Technical Reports Server (NTRS)

    Vannucci, Raymond D. (Inventor); Malarik, Diane C. (Inventor); Delvigs, Peter (Inventor)

    1991-01-01

    Polyimide resins (PMR) are generally useful where high strength and temperature capabilities are required (at temperatures up to about 700 F). Polyimide resins are particularly useful in applications such as jet engine compressor components, for example, blades, vanes, air seals, air splitters, and engine casing parts. Aromatic vinyl capped addition polyimides are obtained by reacting a diamine, an ester of tetracarboxylic acid, and an aromatic vinyl compound. Low void materials with improved oxidative stability when exposed to 700 F air may be fabricated as fiber reinforced high molecular weight capped polyimide composites. The aromatic vinyl capped polyimides are provided with a more aromatic nature and are more thermally stable than highly aliphatic, norbornenyl-type end-capped polyimides employed in PMR resins. The substitution of aromatic vinyl end-caps for norbornenyl end-caps in addition polyimides results in polymers with improved oxidative stability.

  12. Mars ice caps.

    PubMed

    Leovy, C

    1966-12-01

    Minimum atmospheric temperatures required to prevent CO(2) condensatio in the Mars polar caps are higher than those obtained in a computer experiment to simulate the general circulation of the Mars atmosphere. This observation supports the view that the polar caps are predominantly solid CO(2). However, thin clouds of H(2)0 ice could substantially reduce the surface condensation rate.

  13. Opposite responses of rabbit and human globin mRNAs to translational inhibition by cap analogues

    SciTech Connect

    Shakin, S.H.; Liebhaber, S.A.

    1987-11-03

    The translational efficiency of an mRNA may be determined at the step of translational initiation by the efficiency of its interaction with the cap binding protein complex. To further investigate the role of these interactions in translational control, the authors compare in vitro the relative sensitivities of rabbit and human ..cap alpha..- and ..beta..-globin mRNAs to translational inhibition by cap analogues. They find that rabbit ..beta..-globin mRNA is more resistant to translational inhibition by cap analogues than rabbit ..cap alpha..-globin mRNA, while in contrast, human ..beta..-globin mRNA is more sensitive to cap analogue inhibition than human ..cap alpha..- and ..beta..-globin mRNAs is unexpected as direct in vivo and in vitro comparisons of polysome profiles reveal parallel translational handling of the ..cap alpha..- and ..beta..-globin mRNAs from these two species. This discordance between the relative translational sensitivities of these mRNAs to cap analogues and their relative ribosome loading activities suggests that cap-dependent events may not be rate limiting in steady-state globin translation.

  14. CCiCap: Boeing

    NASA Video Gallery

    NASA announced today its plans to partner with The Boeing Company for the next phase of the agency's Commercial Crew Program (CCP). Called Commercial Crew integrated Capability (CCiCap), the initia...

  15. CENTRIFUGE END CAP

    DOEpatents

    Beams, J.W.; Snoddy, L.B.

    1960-08-01

    An end cap for ultra-gas centrifuges is designed to impart or remove angular momentum to or from the gas and to bring the entering gas to the temperature of the gas inside the centrifuge. The end cap is provided with slots or fins for adjusting the temperature and the angular momentum of the entering gas to the temperature and momentum of the gas in the centrifuge and is constructed to introduce both the inner and the peripheral stream into the centrifuge.

  16. ROTOR END CAP

    DOEpatents

    Rushing, F.C.

    1959-02-01

    An improved end cap is described for the cylindrical rotor or bowl of a high-speed centrifugal separator adapted to permit free and efficient continuous counter current flow of gas therethrough for isotope separation. The end cap design provides for securely mounting the same to the hollow central shaft and external wall of the centrifuge. Passageways are incorporated and so arranged as to provide for continuous counter current flow of the light and heavy portions of the gas fed to the centrifuge.

  17. Detection of auroral hydrogen Lyman-Alpha emission from Uranus

    SciTech Connect

    Clarke, J.T.

    1982-12-15

    A series of observations of Uranus obtained with the short-wavelength spectrographs of the International Ultraviolet Explorer Observatory in 1982 April and June have revealed unexpectedly strong H Ly..cap alpha.. emission which varied between 430 and 850 Rayleighs in observed disk-averaged brightness over the course of these observations. The variability of the emission alone indicates that much of the emission must be produced by charged particle excitation of H in Uranus's upper atmosphere. In addition, comparison of these data with a model for resonant scattering of solar H Ly..cap alpha.. emission indicates that, over a wide range of model conditions, an emission brightness of even 430 Rayleighs (which was the lowest observed value) corresponds to an H column density on the order of 10/sup 17/ cm/sup -2/ in Uranus's upper atmosphere. At 20 AU from the Sun, solar EUV photodissociation of H/sub 2/ is insufficient to produce such a high column abundance of H, further supporting the identification of charged particle precipitation in Uranus's upper atmosphere. These data thus offer the first strong evidence for the presence of aurorae and therefore a magnetic field on Uranus.

  18. Do Porins Pass CAPs?

    NASA Astrophysics Data System (ADS)

    Hanna, C. B.; Pink, D. A.; Gill, T. A.; Beveridge, T. J.; Quinn, B. E.; Durrant, J. J.; Jericho, M. H.

    2008-03-01

    The cationic antimicrobial peptide (CAP) protamine is known to inhibit bacterial survival (Pink et al., Langmuir 19, 8852 (2003), and references therein), but the mechanism of attack is as yet undetermined. For Gram-negative bacteria, two pathways have been proposed: (a) self-promoted uptake, and (b) passage through porins. Here, we study the latter possibility, and model part of the outer membrane of a Gram-negative bacterium in an aqueous solution containing multivalent ions and CAPs. The intent is to determine whether CAPs could pass through porins and, if so, what aspects of external (e.g., ionic concentration) and internal (e.g., porin and O-sidechain characteristics) parameters affect their passage. This study is accomplished via Monte Carlo computer simulations of a ``minimal model'' of the outer membrane of a Gram-negative bacterium with an embedded porin.

  19. Magnetospheric polar cap

    NASA Astrophysics Data System (ADS)

    Akasofu, S. I.; Kan, J. R.

    Mount Denali (McKinley), the Alaska Range, and countless glaciers welcomed all 86 participants of the Chapman Conference on the Magnetospheric Polar Cap, which was held on the University of Alaska, Fairbanks campus (UAF), on August 6-9, 1984. The magnetospheric polar cap is the highest latitude region of the earth which is surrounded by the ring of auroras (the auroral oval). This particular region of the earth has become a focus of magnetospheric physicists during the last several years. This is because a number of upper atmospheric phenomena in the polar cap are found to be crucial in understanding the solar wind—magnetosphere interaction. The conference was opened by J. G. Roederer, who was followed by the UAF Chancellor, P. J. O'Rourke, who officially welcomed the participants.

  20. North Polar Cap

    NASA Technical Reports Server (NTRS)

    2004-01-01

    7 September 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a 1.4 m/pixel (5 ft/pixel) view of a typical martian north polar ice cap texture. The surface is pitted and rough at the scale of several meters. The north polar residual cap of Mars consists mainly of water ice, while the south polar residual cap is mostly carbon dioxide. This picture is located near 85.2oN, 283.2oW. The image covers an area approximately 1 km wide by 1.4 km high (0.62 by 0.87 miles). Sunlight illuminates this scene from the lower left.

  1. Commercialization Assistance Program (CAP)

    SciTech Connect

    Jenny C. Servo, Ph.D.

    2004-07-12

    In order to fulfill the objective of Small Business Innovation Research Program (SBIR), the Department of Energy funds an initiative referred to as the Commercialization Assistance Program (CAP). The over-arching purpose of the CAP is to facilitate transition of the SBIR-funded technology to Phase III defined as private sector investment or receipt of non-sbir dollars to further the commercialization of the technology. Phase III also includes increased sales. This report summarizes the stages involved in the implementation of the Commercialization Assistance Program, a program which has been most successful in fulfilling its objectives.

  2. Ice caps on venus?

    PubMed

    Libby, W F

    1968-03-01

    The data on Venus obtained by Mariner V and Venera 4 are interpreted as evidence of giant polar ice caps holding the water that must have come out of the volcanoes with the observed carbon dioxide, on the assumption that Earth and Venus are of similar composition and volcanic history. The measurements by Venera 4 of the equatorial surface temperature indicate that the microwave readings were high, so that the polar ice caps may be allowed to exist in the face of the 10-centimeter readings of polar temperature. Life seems to be distinctly possible at the edges of the ice sheets.

  3. South Polar Cap

    NASA Technical Reports Server (NTRS)

    2005-01-01

    8 December 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows landforms created by sublimation processes on the south polar residual cap of Mars. The bulk of the ice in the south polar residual cap is frozen carbon dioxide.

    Location near: 86.6oS, 342.2oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

  4. [Capping strategies in RNA viruses].

    PubMed

    Bouvet, Mickaël; Ferron, François; Imbert, Isabelle; Gluais, Laure; Selisko, Barbara; Coutard, Bruno; Canard, Bruno; Decroly, Etienne

    2012-04-01

    Most viruses use the mRNA-cap dependent cellular translation machinery to translate their mRNAs into proteins. The addition of a cap structure at the 5' end of mRNA is therefore an essential step for the replication of many virus families. Additionally, the cap protects the viral RNA from degradation by cellular nucleases and prevents viral RNA recognition by innate immunity mechanisms. Viral RNAs acquire their cap structure either by using cellular capping enzymes, by stealing the cap of cellular mRNA in a process named "cap snatching", or using virus-encoded capping enzymes. Many viral enzymes involved in this process have recently been structurally and functionally characterized. These studies have revealed original cap synthesis mechanisms and pave the way towards the development of specific inhibitors bearing antiviral drug potential. PMID:22549871

  5. 3. CAP; CONICAL CAP HAS BOWED RAFTERS MORTISED INTO A ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. CAP; CONICAL CAP HAS BOWED RAFTERS MORTISED INTO A BOSS; ALSO SEEN ARE THE BRAKE WHEEL, WINDSHAFT AND TOP BEARING OF THE UPRIGHT SHAFT - Hayground Windmill, Windmill Lane, East Hampton, Suffolk County, NY

  6. Advising. CAP Job Function.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This Job Function Book (Advising) is one of the 14 components (see note) of the Career Alert Planning (CAP) program, a set of individualized materials designed to help participants find out about themselves and about the kind of work for which they are suited. In this program, participants become acquainted with occupations that are representative…

  7. Guard For Fuse Caps

    NASA Technical Reports Server (NTRS)

    Atwell, D. C.

    1985-01-01

    L-shaped guard attached to fuse holder. Guard prevents casual tampering with fuses in electrical junction box or fuse block. Protects fuses from being damaged by handling or by rope or string used to secure them. With fuse-cap guard, only responsible people have access to fuses.

  8. Arranging. CAP Job Function.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This Job Function Booklet (Arranging) is one of the 14 components (see note) of the Career Alert Planning (CAP) program, a set of individualized materials designed to help participants find out about themselves and about the kind of work for which they are suited. In this program, participants become acquainted with occupations that are…

  9. Anisotropic alpha emission from on-line separated isotopes

    SciTech Connect

    Wouters, J.; Vandeplassche, D.; van Walle, E.; Severijns, N.; Vanneste, L.

    1986-05-05

    A systematic on-line nuclear-orientation study of heavy isotopes using anisotropic ..cap alpha.. emission is reported for the first time. The anisotrophies recorded for /sup 199/At, /sup 201/At, and /sup 203/At are remarkably pronounced and strongly varying. At lower neutron number the ..cap alpha.. particles are more preferentially emitted perpendicularly to the nuclear-spin direction. This may be interpreted in terms of the high sensitivity of the ..cap alpha..-emission probability to changes in the nuclear shape.

  10. Cap protects aircraft nose cone

    NASA Technical Reports Server (NTRS)

    Bryan, C. F., Jr.; Bryan, D. C.

    1981-01-01

    Inexpensive, easily fabricated cap protects aircraft nose cone from erosion. Made of molded polycarbonate, cap has been flight tested at both subsonic and supesonic speeds. Its strength and erosion characteristics are superior to those of fiberglass cones.

  11. Reviews Book: Marie Curie and Her Daughters Resource: Cumulus Equipment: Alpha Particle Scattering Apparatus Equipment: 3D Magnetic Tube Equipment: National Grid Transmission Model Book: Einstein's Physics Equipment: Barton's Pendulums Equipment: Weather Station Web Watch

    NASA Astrophysics Data System (ADS)

    2013-09-01

    WE RECOMMEND Marie Curie and Her Daughters An insightful study of a resilient and ingenious family and their achievements Cumulus Simple to install and operate and with obvious teaching applications, this weather station 'donationware' is as easy to recommend as it is to use Alpha Particle Scattering Apparatus Good design and construction make for good results National Grid Transmission Model Despite its expense, this resource offers excellent value Einstein's Physics A vivid, accurate, compelling and rigorous treatment, but requiring an investment of time and thought WORTH A LOOK 3D Magnetic Tube Magnetic fields in three dimensions at a low cost Barton's Pendulums A neat, well-made and handy variant, but not a replacement for the more traditional version Weather Station Though not as robust or substantial as hoped for, this can be put to good use with the right software WEB WATCH An online experiment and worksheet are useful for teaching motor efficiency, a glance at CERN, and NASA's interesting information on the alpha-magnetic spectrometer and climate change

  12. Designing Smart Charter School Caps

    ERIC Educational Resources Information Center

    Dillon, Erin

    2010-01-01

    In 2007, Andrew J. Rotherham proposed a new approach to the contentious issue of charter school caps, the statutory limits on charter school growth in place in several states. Rotherham's proposal, termed "smart charter school caps," called for quality sensitive caps that allow the expansion of high-performing charter schools while also…

  13. Summer South Polar Cap

    NASA Technical Reports Server (NTRS)

    2004-01-01

    13 April 2004 The martian south polar residual ice cap is composed mainly of frozen carbon dioxide. Each summer, a little bit of this carbon dioxide sublimes away. Pits grow larger, and mesas get smaller, as this process continues from year to year. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a view of a small portion of the south polar cap as it appeared in mid-summer in January 2004. The dark areas may be places where the frozen carbon dioxide contains impurities, such as dust, or places where sublimation of ice has roughened the surface so that it appears darker because of small shadows cast by irregularities in the roughened surface. The image is located near 86.9oS, 7.6oW. The image covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the upper left.

  14. Performance of blasting caps

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J. (Inventor); Schimmel, Morry L. (Inventor); Perry, Ronnie B. (Inventor)

    1993-01-01

    Common blasting caps are made from an aluminum shell in the form of a tube which is closed at both ends. One end, which is called the output end, terminates in a principal side or face, and contains a detonating agent which communicates with a means for igniting the detonating agent. The improvement of the present invention is a flat, steel foil bonded to the face in a position which is aligned perpendicularly to the longitudinal axis of the tube.

  15. North Polar Ice Cap

    NASA Technical Reports Server (NTRS)

    1997-01-01

    North polar ice cap of Mars, as seen during mid summer in the northern hemisphere. The reddish areas consist of eolian dust, bright white areas consist of a mixture of water ice and dust, and the dark blue areas consist of sand dunes forming a huge 'collar' around the polar ice cap. (The colors have been enhanced with a decorrelation stretch to better show the color variability.) Shown here is an oblique view of the polar region, as seen with the Viking 1 spacecraft orbiting Mars over latitude 39 degrees north. The spiral bands consist of valleys which form by a combination of the Coriolis forces, wind erosion, and differential sublimation and condensation. In high-resolution images the polar caps are seen to consist of thick sequences of layered deposits, suggesting that cyclical climate changes have occurred on Mars. Cyclical climate changes are readily explained by quasi-periodic changes in the amount and distribution of solar heating resulting from perturbations in orbital and axial elements. Variations in the Earth's orbit have also been linked to the terrestrial climate changes during the ice ages.

  16. Direct Measurement of {sup 21}Na+{alpha} Stellar Reaction

    SciTech Connect

    Binh, D. N.; Kubono, S.; Yamaguchi, H.; Hayakawa, S.; Hashimoto, T.; Kahl, D.; Teranishi, T.; Iwasa, N.; Kume, N.; Kato, S.; Khiem, L. H.; Tho, N. T.; Wakabayashi, Y.

    2010-08-12

    The measurement of the resonant alpha scattering and the {sup 21}Na({alpha}, p) reaction were performed for the first time in inverse kinematics with the thick target method using a {sup 21}Na radioisotope (RI) beam. This paper reports the current result of alpha scattering measurement and its astrophysics implication.

  17. Saltstone Clean Cap Formulation

    SciTech Connect

    Langton, C

    2005-04-22

    The current operation strategy for using Saltstone Vault 4 to receive 0.2 Ci/gallon salt solution waste involves pouring a clean grout layer over the radioactive grout prior to initiating pour into another cell. This will minimize the radiating surface area and reduce the dose rate at the vault and surrounding area. The Clean Cap will be used to shield about four feet of Saltstone poured into a Z-Area vault cell prior to moving to another cell. The minimum thickness of the Clean Cap layer will be determined by the cesium concentration and resulting dose levels and it is expected to be about one foot thick based on current calculations for 0.1 Ci Saltstone that is produced in the Saltstone process by stabilization of 0.2 Ci salt solution. This report documents experiments performed to identify a formulation for the Clean Cap. Thermal transient calculations, adiabatic temperature rise measurements, pour height, time between pour calculations and shielding calculations were beyond the scope and time limitations of this study. However, data required for shielding calculations (composition and specific gravity) are provided for shielding calculations. The approach used to design a Clean Cap formulation was to produce a slurry from the reference premix (10/45/45 weight percent cement/slag/fly ash) and domestic water that resembled as closely as possible the properties of the Saltstone slurry. In addition, options were investigated that may offer advantages such as less bleed water and less heat generation. The options with less bleed water required addition of dispersants. The options with lower heat contained more fly ash and less slag. A mix containing 10/45/45 weight percent cement/slag/fly ash with a water to premix ratio of 0.60 is recommended for the Clean Cap. Although this mix may generate more than 3 volume percent standing water (bleed water), it has rheological, mixing and flow properties that are similar to previously processed Saltstone. The recommended

  18. DEAD ZONE IN THE POLAR-CAP ACCELERATOR OF PULSARS

    SciTech Connect

    Chen, Alexander Y.; Beloborodov, Andrei M.

    2013-01-10

    We study plasma flows above pulsar polar caps using time-dependent simulations of plasma particles in the self-consistent electric field. The flow behavior is controlled by the dimensionless parameter {alpha} = j/c{rho}{sub GJ}, where j is the electric current density and {rho}{sub GJ} is the Goldreich-Julian charge density. The region of the polar cap where 0 < {alpha} < 1 is a {sup d}ead zone{sup -}in this zone, particle acceleration is inefficient and pair creation is not expected even for young, rapidly rotating pulsars. Pulsars with polar caps near the rotation axis are predicted to have a hollow-cone structure of radio emission, as the dead zone occupies the central part of the polar cap. Our results apply to charge-separated flows of electrons (j < 0) or ions (j > 0). In the latter case, we consider the possibility of a mixed flow consisting of different ion species, and observe the development of two-stream instability. The dead zone at the polar cap is essential for the development of an outer gap near the null surface {rho}{sub GJ} = 0.

  19. Alpha-decay of light protactinium isotopes

    SciTech Connect

    Faestermann, T.; Gillitzer, A.; Hartel, K.; Henning, W.; Kienle, P.

    1987-12-10

    Light protactinium isotopes have been produced with /sup 204/Pb (/sup 19/F,xn) reactions. ..cap alpha..-activities with E/sub ..cap alpha../ = 9.90(5) MeV, T/sub 1/2/ = 53(10) ns and E/sub ..cap alpha../ = 9.65(5) MeV, T/sub 1/2/ = 0.78(16) ..mu..s could be attributed to the previously unobserved nuclei /sup 219/Pa and /sup 220/Pa with the help of excitation functions. The peak cross sections for the 4n and 3n evaporation channels are on the order of 10 ..mu..b. The decay energies as well as the halflives fit well into the systematics of these nuclei close to the magic neutron number N = 126. /sup 219/Pa is the shortest lived nuclide known with directly measured halflife.

  20. Vinyl capped addition polyimides

    NASA Technical Reports Server (NTRS)

    Vannucci, Raymond D. (Inventor); Malarik, Diane C. (Inventor); Delvigs, Peter (Inventor)

    1990-01-01

    Polyimide resins having improved thermo-oxidative stability are provided having aromatic vinyl end-caps. The polyimides are prepared by the reaction of a mixture of monomers comprising (1) a diamine, (2) an ester of tetracarboxylic acid and (3) an aromatic vinyl compound in a molar ratio of 1:2:3 of n: (n + 1):2 when the aromatic vinyl compound contains nitrogen and in a ratio of (n + 1):n:2 when the aromatic vinyl compound does not contain nitrogen, wherein n ranges from about 5 to about 20.

  1. Novel Multipin Electrode Cap System for Dry Electroencephalography.

    PubMed

    Fiedler, P; Pedrosa, P; Griebel, S; Fonseca, C; Vaz, F; Supriyanto, E; Zanow, F; Haueisen, J

    2015-09-01

    Current usage of electroencephalography (EEG) is limited to laboratory environments. Self-application of a multichannel wet EEG caps is practically impossible, since the application of state-of-the-art wet EEG sensors requires trained laboratory staff. We propose a novel EEG cap system with multipin dry electrodes overcoming this problem. We describe the design of a novel 24-pin dry electrode made from polyurethane and coated with Ag/AgCl. A textile cap system holds 97 of these dry electrodes. An EEG study with 20 volunteers compares the 97-channel dry EEG cap with a conventional 128-channel wet EEG cap for resting state EEG, alpha activity, eye blink artifacts and checkerboard pattern reversal visual evoked potentials. All volunteers report a good cap fit and good wearing comfort. Average impedances are below 150 kΩ for 92 out of 97 dry electrodes, enabling recording with standard EEG amplifiers. No significant differences are observed between wet and dry power spectral densities for all EEG bands. No significant differences are observed between the wet and dry global field power time courses of visual evoked potentials. The 2D interpolated topographic maps show significant differences of 3.52 and 0.44% of the map areas for the N75 and N145 VEP components, respectively. For the P100 component, no significant differences are observed. Dry multipin electrodes integrated in a textile EEG cap overcome the principle limitations of wet electrodes, allow rapid application of EEG multichannel caps by non-trained persons, and thus enable new fields of application for multichannel EEG acquisition.

  2. Polar Cap Pits

    NASA Technical Reports Server (NTRS)

    2005-01-01

    17 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows kidney bean-shaped pits, and other pits, formed by erosion in a landscape of frozen carbon dioxide. This images shows one of about a dozen different patterns that are common in various locations across the martian south polar residual cap, an area that has been receiving intense scrutiny by the MGS MOC this year, because it is visible on every orbit and in daylight for most of 2005.

    Location near: 86.9oS, 6.9oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  3. South Polar Ice Cap

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-337, 21 April 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the 'swiss cheese' pattern of frozen carbon dioxide on the south polar residual cap. Observation of these materials over two Mars years has revealed that the scarps that bound the mesas and small buttes are retreating-the carbon dioxide ice is subliming away-at a rate of about 3 meters (3 yards) per Mars year in some places. The picture covers an area about 900 m (about 900 yards) wide near 87.1oS, 93.7oW. Sunlight illuminates the scene from the upper left.

  4. Laser rods with undoped, flanged end-caps for end-pumped laser applications

    DOEpatents

    Meissner, Helmuth E.; Beach, Raymond J.; Bibeau, Camille; Sutton, Steven B.; Mitchell, Scott; Bass, Isaac; Honea, Eric

    1999-01-01

    A method and apparatus for achieving improved performance in a solid state laser is provided. A flanged, at least partially undoped end-cap is attached to at least one end of a laserable medium. Preferably flanged, undoped end-caps are attached to both ends of the laserable medium. Due to the low scatter requirements for the interface between the end-caps and the laser rod, a non-adhesive method of bonding is utilized such as optical contacting combined with a subsequent heat treatment of the optically contacted composite. The non-bonded end surfaces of the flanged end-caps are coated with laser cavity coatings appropriate for the lasing wavelength of the laser rod. A cooling jacket, sealably coupled to the flanged end-caps, surrounds the entire length of the laserable medium. Radiation from a pump source is focussed by a lens duct and passed through at least one flanged end-cap into the laser rod.

  5. Measurement of. cap alpha. /sub s/. [Strong fine structure constant

    SciTech Connect

    Clavelli, L.

    1983-01-01

    We point out that a number of QCD tests, relatively free of obvious nonperturbative corrections and other theoretical problems, are now available in e/sup +/e/sup -/ annihilation. By focusing on these tests, one can see the beginning of a confirmation of the running of the strong-coupling constant predicted by the renormalization group.

  6. South Polar Cap

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 8 March 2004

    The Odyssey spacecraft has completed a full Mars year of observations of the red planet. For the next several weeks the Image of the Day will look back over this first mars year. It will focus on four themes: 1) the poles - with the seasonal changes seen in the retreat and expansion of the caps; 2) craters - with a variety of morphologies relating to impact materials and later alteration, both infilling and exhumation; 3) channels - the clues to liquid surface flow; and 4) volcanic flow features. While some images have helped answer questions about the history of Mars, many have raised new questions that are still being investigated as Odyssey continues collecting data as it orbits Mars.

    This image was collected March 5, 2002 during the southern summer season. Layering in the South polar cap interior is readily visible and may indicate yearly ice/dust deposition.

    Image information: VIS instrument. Latitude -86.6, Longitude 156.8 East (203.2 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the

  7. Method for determining fast-alpha-particle confinement in tokamak plasmas using resonant nuclear reactors

    SciTech Connect

    Cecil, F.E.; Zweben, S.J.; Medley, S.S.

    1986-03-01

    The resonant nuclear reactions D(..cap alpha..,..gamma..)/sup 6/Li, /sup 6/Li(..cap alpha..,..gamma..)/sup 10/B, and /sup 7/Li(..cap alpha..,..gamma..)/sup 11/B are examined as diagnostics of fast-alpha-particle confinement in tokamak plasmas. Gamma rays from these resonant reactions with energies from 2.1 MeV to 9.2 MeV may be used to infer the alpha-particle population between energies of 0.4 MeV and 2.6 MeV. The ratio of these alpha-burnup reactions to the reactions T(D,..gamma..)/sup 5/He and /sup 3/He(D,..gamma..)/sup 5/Li provides a technique for the measurement of alpha confinement.

  8. Small-angle x-ray scattering studies of calmodulin mutants with deletions in the linker region of the central helix indicate that the linker region retains a predominantly. alpha. -helical conformation

    SciTech Connect

    Kataoka, Mikio; Engelman, D.M. ); Head, J.F. ); Persechini, A.; Kretsinger, R.H. )

    1991-02-05

    Two mutant forms of calmodulin were examined by small-angle X-ray scattering in solution and compared with the wild-type protein. Each mutant has deletions in the linker region of the central helix: one lacks residues Glu-83 and Glu-84 (Des2) and the other lacks residues Ser-81 through Glu-84 (Des4). The deletions change both the radii of gyration and the maximum dimensions of the molecules. In the presence of Ca{sup 2+}, the observed radii of gyration are 22.4 {angstrom} for wild-type bacterially expressed calmodulin, 19.5 {angstrom} for Des2 calmodulin, and 20.3 {angstrom} for Des4 calmodulin. A reduction in the radius of gyration by 1-2 {angstrom} on removal of calcium, previously observed in the native protein, was also found in the wild type and the Des4 mutant; however, no significant size change was observed in the Des2 mutant. The large calcium-dependent conformational change in calmodulin induced by the binding of melittin was observed in all the bacterially expressed proteins. Each protein appears to undergo a transition from a dumbbell shape to a more globular conformation on binding melittin in the presence of calcium, although quantitatively the changes in the wild-type and Des4 proteins greatly exceed those in Des2. Modeling shows that the structural properties of the deletion mutants are well described by modifications of an {alpha} helix in the central linker region of the molecule. Thus, the structure of the linker region is stable enough to maintain the average orientation and separation of the lobes yet flexible enough to permit the lobes to approach each other upon binding a peptide.

  9. Genetics Home Reference: cap myopathy

    MedlinePlus

    ... Groote C, de Jonghe P, Marttila M, Laing NG, Pelin K, Wallgren-Pettersson C. Cap disease caused ... E, Wallefeld W, Memo M, Donner K, Laing NG, Marston S, Grönholm M, Wallgren-Pettersson C. Abnormal actin ...

  10. Stuck fuel rod capping sleeve

    DOEpatents

    Gorscak, Donald A.; Maringo, John J.; Nilsen, Roy J.

    1988-01-01

    A stuck fuel rod capping sleeve to be used during derodding of spent fuel assemblies if a fuel rod becomes stuck in a partially withdrawn position and, thus, has to be severed. The capping sleeve has an inner sleeve made of a lower work hardening highly ductile material (e.g., Inconel 600) and an outer sleeve made of a moderately ductile material (e.g., 304 stainless steel). The inner sleeve may be made of an epoxy filler. The capping sleeve is placed on a fuel rod which is then severed by using a bolt cutter device. Upon cutting, the capping sleeve deforms in such a manner as to prevent the gross release of radioactive fuel material

  11. Biologically inspired stealth peptide-capped gold nanoparticles.

    PubMed

    Nowinski, Ann K; White, Andrew D; Keefe, Andrew J; Jiang, Shaoyi

    2014-02-25

    Introduction into the human body makes most nanoparticle systems susceptible to aggregation via nonspecific protein binding. Here, we developed a peptide-capped gold nanoparticle platform that withstands aggregation in undiluted human serum at 37 °C for 24 h. This biocompatible and natural system is based on mimicking human proteins which are enriched in negatively charged glutamic acid and positively charged lysine residues on their surface. The multifunctional EKEKEKE-PPPPC-Am peptide sequence consists of a stealth glutamic acid/lysine portion combined with a surface anchoring linker containing four prolines and a cysteine. Particle stability was measured via optical spectroscopy and dynamic light scattering in single protein, high salt, and undiluted human serum solutions. In vitro cell experiments demonstrate EKEKEKE-PPPPC-Am capped gold nanoparticles effectively minimize nonspecific cell uptake by nonphagocytic bovine aortic endothelial cells and phagocytic murine macrophage RAW 264.7 cells. Cytotoxicity studies show that peptide-capped gold nanoparticles do not affect cell viability. Finally, the peptide EKEKEKE-PPPPC-Am was extended with cyclic RGD to demonstrate specific cell targeting and stealth without using poly(ethylene glycol). Adding the functional peptide via peptide sequence extension avoids complex conjugation chemistries that are used for connection to synthetic materials. Inductively coupled plasma mass spectroscopy results indicate high aortic bovine endothelial cell uptake of c[RGDfE(SGG-KEKEKE-PPPPC-Am)] capped gold nanoparticles and low uptake of the control scrambled sequence c[RDGfE(SGG-KEKEKE-PPPPC-Am)] capped gold nanoparticles.

  12. Polar cap auroral arcs: Observations, theories, and a numerical model

    SciTech Connect

    Berg, G.A.

    1993-12-31

    This thesis reports the results of probably the most completely documented study of auroras near the polar cap boundary performed to date. Three fully instrumented rockets flew into the morning sector of the polar cap, complemented on the ground by a digital all-sky camera and incoherent scatter radar. Additionally, DMSP satellite passes over the polar cap bracketed the launches. We use these data to address two main issues: (1) the relationship between the state of the magnetosphere and the formation of polar cap arcs, and (2) the character of the current systems associated with polar cap arcs. The data indicate that in a decaying magnetosphere sun-aligned arcs erupt into the polar cap at high velocity from regions of enhanced brightness in the auroral oval. Two bright polar cap arcs formed in this manner in the region sampled by the rockets. The most equatorward of the arcs, sampled by two of the rockets during its lifetime, erupted into a region already characterized by strong sunward convection. The most poleward, however, which formed after the rockets had passed, pushed into a region where anti-sunward convection pertained less than two minutes earlier. It is likely that the boundary between sunward and anti-sunward convection shifted poleward so that sunward convection pertained at this arc as well. One of the payloads measured, with high resolution, both E and {delta}B as well as energetic particle flux. This permitted an in-depth study of the current systems flown through. The correlation between {delta}E and {delta}B is classic, both fields indicating upward field-aligned currents in virtually every region of enhanced electron precipitation. However, the currents deduced from the electrons do not agree in magnitude with those deduced from the fields. The conclusion is that for arcs embedded in a region of low {Sigma}{sub P} a current composed of upward thermal electrons flows concurrently with the precipitating electrons.

  13. A study of auroral activity in the nightside polar cap

    SciTech Connect

    Wu, Q.

    1989-01-01

    Using various ground observations at South Pole, Antarctica (invariant magnetic latitude -74{degree}) and its conjugate point, Frobisher Bay, Canada, the author has studied the following aspects of nightside polar cap auroral activity: the appearance and disappearance of polar cap auroras (diffuse and discrete) associated with substorms and interplanetary magnetic field (IMF) variations; auroral optical emission line intensities; and the seasonal variation of auroral conjugacy. The observations show that the polar cap auroras usually fade away before the expansive phase of a substorm and bright auroral arcs reach high latitude (-74{degree}) near the recovery phase. Just before the auroras fade away the discrete polar cap auroral arcs, which are usually on the poleward boundary of the diffuse aurora, intensify for 1 to 2 minutes. The observations also indicate the IMF may have stronger control over polar cap auroral activity than do substorms. A search for energy spectral variation of precipitating electrons using the intensities of 630.0 nm (0) and 427 nm (N{sub 2}{sup +}) auroral emission lines reveals no dramatic changes in the energy spectrum; instead, the data show possible atmospheric scattering and geometric effects on the photometric measurements while the bright auroral arc is moving into the polar cap. The conjugate observations show that the stormtime auroral electrojet current, which is associated with the bright auroral arc, in most cases reaches higher (lower) latitudes in the winter (summer) hemisphere. An asymmetric plasma sheet (with respect to the neutral sheet) is proposed, which expands deeper into the winter lobe, under a tilted geomagnetic dipole. Accordingly, the winter polar cap would have smaller area and the auroral electrojet would be at higher latitude.

  14. Polar Cap Colors

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 12 May 2004 This daytime visible color image was collected on June 6, 2003 during the Southern Spring season near the South Polar Cap Edge.

    The THEMIS VIS camera is capable of capturing color images of the martian surface using its five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from the use of multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    Image information: VIS instrument. Latitude -77.8, Longitude 195 East (165 West). 38 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA

  15. Alpha Thalassemia

    MedlinePlus

    ... an apparently normal individual has a child with hemoglobin H disease or alpha thalassemia minor. It can ... gene on one chromosome 25% 25% 25% 25% hemoglobin H disease there is a 25% chance with ...

  16. Mathematical modeling of cold cap

    SciTech Connect

    Pokorny, Richard; Hrma, Pavel R.

    2012-10-13

    The ultimate goal of studies of cold cap behavior in glass melters is to increase the rate of glass processing in an energy-efficient manner. Regrettably, mathematical models, which are ideal tools for assessing the responses of melters to process parameters, have not paid adequate attention to the cold cap. In this study, we consider a cold cap resting on a pool of molten glass from which it receives a steady heat flux while temperature, velocity, and extent of conversion are functions of the position along the vertical coordinate. A one-dimensional (1D) mathematical model simulates this process by solving the differential equations for mass and energy balances with appropriate boundary conditions and constitutive relationships for material properties. The sensitivity analyses on the effects of incoming heat fluxes to the cold cap through its lower and upper boundaries show that the cold cap thickness increases as the heat flux from above increases, and decreases as the total heat flux increases. We also discuss the effects of foam, originating from batch reactions and from redox reactions in molten glass and argue that models must represent the foam layer to achieve a reliable prediction of the melting rate as a function of feed properties and melter conditions.

  17. Polar Cap Plasma and Convection

    NASA Technical Reports Server (NTRS)

    Elliott, Heather A.; Craven, Paul D.; Comfort, Richard H.; Chandler, Michael O.; Moore, Thomas E.; Ruohoniemi, J. M.

    1998-01-01

    This presentation will describe the character of the polar cap plasma in 10% AGU Spring 1998 particular the convection velocities at the perigee (about 1.8 Re) and apogee( about 8.9 Re) of Polar in relationship to Interplanetary Magnetic Field (IMF) and solar wind parameters. This plasma is thought to be due to several sources; the polar wind, cleft ion fountain, and auroral outflow. The plasma in the polar cap tends to be mostly field-aligned. At any given point in the polar cap, this plasma could be from a different regions since convection of magnetic field lines can transport this material. it is quite difficult to study such a phenomena with single point measurements. Current knowledge of the polar cap plasma obtained by in situ measurements will be presented along with recent results from the Polar mission. This study also examines the direct electrical coupling between the magnetosphere and ionosphere by comparing convection velocities measured by the Thermal Ion Dynamics Experiment (TIDE) and Magnetic Field Experiment (MFE) instruments in magnetosphere and measurements of the ionosphere by ground-based radars. At times such a comparison is difficult because the Polar satellite at apogee spends a large amount of time in the polar cap which is a region that is not coverage well by the current SuperDam coherent radars. This is impart due to the lack of irregularities that returns the radar signal.

  18. South Polar Residual Ice Cap

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This mosaic is composed of 18 Viking Orbiter images (6 each in red, green, and violet filters), acquired on September 28, 1977, during revolution 407 of Viking Orbiter 2. The south pole is located just off the lower left edge of the polar cap, and the 0 degree longitude meridian extends toward the top of the mosaic. The large crater near the right edge (named 'South') is about 100 km in diameter. These images were acquired during southern summer on Mars (Ls = 341 degrees); the sub-solar declination was 8 degrees S., and the south polar cap was nearing its final stage of retreat just prior to vernal equinox. The south residual cap is approximately 400 km across, and the exposed surface is thought to consist dominantly of carbon-dioxide frost. This is in contrast to the water-ice surface of the north polar residual cap. It is likely that water ice is present in layers that underlie the south polar cap and that comprise the surrounding layered terrains. Near the top of this image, irregular pits with sharp-rimmed cliffs appear 'etched', presumably by wind. A series of rugged mountains (extending toward the upper right corner of the image) are of unknown origin.

  19. Studies of alpha-induced astrophysical reactions at CRIB

    SciTech Connect

    Yamaguchi, H.; Hashimoto, T.; Hayakawa, S.; Binh, D. N.; Kahl, D.; Kubono, S.

    2010-08-12

    CRIB (CNS Radioactive Ion Beam separator) is a low-energy RI beam separator at the Center for Nuclear Study (CNS) of the University of Tokyo. Using the RI beams at CRIB, many measurements on proton alpha resonance scatterings, ({alpha},p) reactions, and others were performed in recent years mainly for studying astrophysical reactions and exotic nuclear structure. Among them, the results on the {sup 7}Li+{alpha} resonance scatterings are presented.

  20. THE LYMAN ALPHA REFERENCE SAMPLE: EXTENDED LYMAN ALPHA HALOS PRODUCED AT LOW DUST CONTENT

    SciTech Connect

    Hayes, Matthew; Oestlin, Goeran; Duval, Florent; Guaita, Lucia; Melinder, Jens; Sandberg, Andreas; Schaerer, Daniel; Verhamme, Anne; Orlitova, Ivana; Mas-Hesse, J. Miguel; Oti-Floranes, Hector; Adamo, Angela; Atek, Hakim; Cannon, John M.; Herenz, E. Christian; Kunth, Daniel; Laursen, Peter

    2013-03-10

    We report on new imaging observations of the Lyman alpha emission line (Ly{alpha}), performed with the Hubble Space Telescope, that comprise the backbone of the Lyman alpha Reference Sample. We present images of 14 starburst galaxies at redshifts 0.028 < z < 0.18 in continuum-subtracted Ly{alpha}, H{alpha}, and the far ultraviolet continuum. We show that Ly{alpha} is emitted on scales that systematically exceed those of the massive stellar population and recombination nebulae: as measured by the Petrosian 20% radius, R{sub P20}, Ly{alpha} radii are larger than those of H{alpha} by factors ranging from 1 to 3.6, with an average of 2.4. The average ratio of Ly{alpha}-to-FUV radii is 2.9. This suggests that much of the Ly{alpha} light is pushed to large radii by resonance scattering. Defining the Relative Petrosian Extension of Ly{alpha} compared to H{alpha}, {xi}{sub Ly{alpha}} = R {sup Ly{alpha}}{sub P20}/R {sup H{alpha}}{sub P20}, we find {xi}{sub Ly{alpha}} to be uncorrelated with total Ly{alpha} luminosity. However, {xi}{sub Ly{alpha}} is strongly correlated with quantities that scale with dust content, in the sense that a low dust abundance is a necessary requirement (although not the only one) in order to spread Ly{alpha} photons throughout the interstellar medium and drive a large extended Ly{alpha} halo.

  1. Crystal structure of Bacillus anthracis transpeptidase enzyme CapD.

    SciTech Connect

    Wu, R.; Richter, S.; Zhang, R.; Anderson, V. J.; Missiakas, D.; Joachimiak, A.; Biosciences Division; Univ. of Chicago

    2009-09-04

    Bacillus anthracis elaborates a poly-{gamma}-d-glutamic acid capsule that protects bacilli from phagocytic killing during infection. The enzyme CapD generates amide bonds with peptidoglycan cross-bridges to anchor capsular material within the cell wall envelope of B. anthracis. The capsular biosynthetic pathway is essential for virulence during anthrax infections and can be targeted for anti-infective inhibition with small molecules. Here, we present the crystal structures of the {gamma}-glutamyltranspeptidase CapD with and without {alpha}-l-Glu-l-Glu dipeptide, a non-hydrolyzable analog of poly-{gamma}-d-glutamic acid, in the active site. Purified CapD displays transpeptidation activity in vitro, and its structure reveals an active site broadly accessible for poly-{gamma}-glutamate binding and processing. Using structural and biochemical information, we derive a mechanistic model for CapD catalysis whereby Pro{sup 427}, Gly{sup 428}, and Gly{sup 429} activate the catalytic residue of the enzyme, Thr{sup 352}, and stabilize an oxyanion hole via main chain amide hydrogen bonds.

  2. Polar Cap Formation on Ganymede

    NASA Technical Reports Server (NTRS)

    Pilcher, C. B.; Shaya, E. J.

    1985-01-01

    Since thermal migration is not an effective mechanism for water transport in the polar regions at the Galilean satellites, some other process must be responsible for the formation of Ganymede's polar caps. It is proposed that Ganymede's polar caps are the optical manifestation of a process that began with the distribution of an ice sheet over the surface of Ganymede. The combined processes of impact gardening and thermal migration led, in regions at latitudes less than 40 to 45 deg., to the burial of some fraction of this ice, the migration of some to the polar caps margins, and a depletion of free ice in the optical surface. At higher latitudes, no process was effective in removing ice from the optical surface, so the remanants of the sheet are visible today.

  3. Polar cap formation on Ganymede

    NASA Technical Reports Server (NTRS)

    Shaya, E. J.; Pilcher, C. B.

    1984-01-01

    It is argued that Ganymede's polar caps are the remnants of a more extensive covering of water ice that formed during a period in which the satellite was geologically active. It is inferred that the initial thickness of this covering was a significant fraction of the gardening depth since the covering formed. This suggests an initial thickness of at least a few meters over heavily cratered regions such as the south polar grooved terrain. The absence of similar polar caps on Callisto apparently reflects the absence of comparable geologic activity in the history of this satellite.

  4. The Enigmatic Martian Polar Caps

    SciTech Connect

    James, Philip

    2005-08-17

    The Martian polar caps have puzzled astronomers for over a century. Extensive study by many instruments on various spacecraft has resolved many questions but has at the same time created a new generation of puzzles. The polar caps are intimately coupled to the current Martian climate and volatile cycles. They also hold clues to climate variations on a variety of longer time scales. The results of recent missions will be reviewed, and the potential outlook for resolution of the outstanding questions will be examined.

  5. Structural characterisation of alkyl amine-capped zinc sulphide nanoparticles

    PubMed Central

    Kremser, Gabriele; Rath, Thomas; Kunert, Birgit; Edler, Michael; Fritz-Popovski, Gerhard; Resel, Roland; Letofsky-Papst, Ilse; Grogger, Werner; Trimmel, Gregor

    2012-01-01

    Nanoparticles capped with amine ligands with different steric properties, dodecylamine and oleylamine, respectively, are investigated in the solid state as well as in solution. A combined X-ray diffraction, small angle X-ray scattering and electron microscopy investigation showed that the nanoparticles exhibit the sphalerite modification of ZnS as crystal phase with a diameter of 3–5 nm. A close packing of the monocrystalline nanoparticles in the solid state is observed. However, in the dodecylamine sample, besides spherical particles, a fraction of the nanoparticles is elongated. The nanoparticles are readily resoluble in apolar solvents like hexane. Dynamic light scattering (DLS) and SAXS investigations of the solutions reveal that the nanoparticles are dissolved as singular particles. In the case of oleylamine-capped ZnS, a defined core–shell structure with a ZnS core with a diameter of 4 nm and an organic shell with a thickness of approximately 2 nm have been found. Dodecylamine-capped nanoparticles slightly tend to form agglomerates with a diameter of approximately 40 nm. PMID:22239986

  6. Structural characterisation of alkyl amine-capped zinc sulphide nanoparticles.

    PubMed

    Kremser, Gabriele; Rath, Thomas; Kunert, Birgit; Edler, Michael; Fritz-Popovski, Gerhard; Resel, Roland; Letofsky-Papst, Ilse; Grogger, Werner; Trimmel, Gregor

    2012-03-01

    Nanoparticles capped with amine ligands with different steric properties, dodecylamine and oleylamine, respectively, are investigated in the solid state as well as in solution. A combined X-ray diffraction, small angle X-ray scattering and electron microscopy investigation showed that the nanoparticles exhibit the sphalerite modification of ZnS as crystal phase with a diameter of 3-5 nm. A close packing of the monocrystalline nanoparticles in the solid state is observed. However, in the dodecylamine sample, besides spherical particles, a fraction of the nanoparticles is elongated. The nanoparticles are readily resoluble in apolar solvents like hexane. Dynamic light scattering (DLS) and SAXS investigations of the solutions reveal that the nanoparticles are dissolved as singular particles. In the case of oleylamine-capped ZnS, a defined core-shell structure with a ZnS core with a diameter of 4 nm and an organic shell with a thickness of approximately 2 nm have been found. Dodecylamine-capped nanoparticles slightly tend to form agglomerates with a diameter of approximately 40 nm. PMID:22239986

  7. Enhanced thermal stability of phosphate capped magnetite nanoparticles

    SciTech Connect

    Muthukumaran, T.; Philip, John

    2014-06-14

    We have studied the effect of phosphate capping on the high temperature thermal stability and magnetic properties of magnetite (Fe{sub 3}O{sub 4}) nanoparticles synthesized through a single-step co-precipitation method. The prepared magnetic nanoparticles are characterized using various techniques. When annealed in air, the phosphate capped nanoparticle undergoes a magnetic to non-magnetic phase transition at a temperature of 689 °C as compared to 580 °C in the uncoated nanoparticle of similar size. The observed high temperature phase stability of phosphate capped nanoparticle is attributed to the formation of a phosphocarbonaceous shell over the nanoparticles, which acts as a covalently attached protective layer and improves the thermal stability of the core material by increasing the activation energy. The phosphocarbonaceous shell prevents the intrusion of heat, oxygen, volatiles, and mass into the magnetic core. At higher temperatures, the coalescence of nanoparticles occurs along with the restructuring of the phosphocarbonaceous shell into a vitreous semisolid layer on the nanoparticles, which is confirmed from the small angle X-ray scattering, Fourier transform infra red spectroscopy, and transmission electron microscopy measurements. The probable mechanism for the enhancement of thermal stability of phosphocarbonaceous capped nanoparticles is discussed.

  8. Indirect pulp capping: a survey.

    PubMed

    Kaplowitz, G J

    1992-01-01

    This study addresses the acceptance of the clinical practice of indirect pulp capping. State and regional dental boards and postgraduate dental education programs throughout the United States were surveyed. Results indicate that no clear consensus exists for the acceptance of this clinical procedure.

  9. From Blogs to Bottle Caps

    ERIC Educational Resources Information Center

    Edinger, Ted

    2012-01-01

    There is a wonderful community of art educators connecting a once-isolated profession through blogging. Art educators around the world are sharing ideas and communicating with their peers through this amazing resource. In this article, the author describes the bottle cap mural at Tulip Grove Elementary School which was inspired by this exchange of…

  10. Alpha-1 Antitrypsin Deficiency

    MedlinePlus

    ... Liver Disease Information > Alpha-1 Antitrypsin Deficiency Alpha-1 Antitrypsin Deficiency Explore this section to learn more about alpha-1 antitrypsin deficiency, including a description of the disorder ...

  11. Polar cap F layer patches: structure and dynamics

    SciTech Connect

    Weber, E.J.; Klobuchar, J.A.; Buchau, J.; Carlson, H.C.; Livingston, R.C.

    1986-11-01

    Coordinated measurements of F-region plasma patches were conducted on February 3/4, 1984, from Thule and Sondrestrom, Greenland. Optical, ionsonde, amplitude scintillation, total electron content (TEC), and incoherent scatter radar measurements were combined to reveal several new aspects of the structure and transport of these localized regions of enhanced F region ionization. For the first time, these patches were directly tracked flowing in the antisunward direction over distances of 3000 km from the center of the polar cap to the poleward edge of the auroral oval. Quantative measurements of TEC show increases of 10-15 TEC units within the patches, above a background polar cap value of 5 TEC units. Amplitude scintillation measurements show the presence of ionospheric irregularities through the entire patch, with a weak indication of stronger scintillation on the trailing (or E x B unstable) edge.

  12. Polar cap F layer patches: structure and dynamics

    SciTech Connect

    Weber, E.J.; Klobuchar, J.A.; Buchau, J.; Carlson H.C. Jr.; Livingston, R.C.; De La Beaujardiere, O.; McCready, M.; Moore, J.G.; Bishop, G.J.

    1986-11-01

    Coordinated measurements of F region plasma patches were conducted on February 3/4, 1984, from Thule and Sondrestrom, Greenland. Optical, ionosonde, amplitude scintillation, total electron content (TEC), and incoherent scatter radar measurements were combined to reveal several new aspects of the structure and transport of these localized regions of enhanced F region ionization. For the first time these patches were directly tracked flowing in the antisunward direction over distances of 3000 km from the center of the polar cap to the poleward edge of the auroral oval. Quantitative measurements of TEC show increases of 10--15 TEC units within the patches, above a background polar cap value of 5 TEC units. Amplitude scintillation measurements show the presence of ionospheric irregularities through the entire patch, with a weak indication of stronger scintillation on the trailing (or E x B unstable) edge.

  13. Tip cap for a rotor blade

    NASA Technical Reports Server (NTRS)

    Kofel, W. K.; Tuley, E. N.; Gay, C. H., Jr.; Troeger, R. E.; Sterman, A. P. (Inventor)

    1983-01-01

    A replaceable tip cap for attachment to the end of a rotor blade is described. The tip cap includes a plurality of walls defining a compartment which, if desired, can be divided into a plurality of subcompartments. The tip cap can include inlet and outlet holes in walls thereof to permit fluid communication of a cooling fluid there through. Abrasive material can be attached with the radially outer wall of the tip cap.

  14. 47 CFR 54.507 - Cap.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Universal Service Support for Schools and Libraries § 54.507 Cap. (a) Amount of the annual cap. The annual funding cap on federal universal service support for schools and libraries shall be $2.25 billion per... into subsequent funding years for use in the schools and libraries support mechanism in accordance...

  15. Dynamic Modeling of an Evapotranspiration Cap

    SciTech Connect

    Jacob J. Jacobson; Steven Piet; Rafael Soto; Gerald Sehlke; Harold Heydt; John Visser

    2005-10-01

    The U.S. Department of Energy is scheduled to design and install hundreds of landfill caps/barriers over the next several decades and these caps will have a design life expectancy of up to 1,000 years. Other landfill caps with 30 year design lifetimes are reaching the end of their original design life; the changes to these caps need to be understood to provide a basis for lifetime extension. Defining the attributes that make a successful cap (one that isolates the waste from the environment) is crucial to these efforts. Because cap systems such as landfill caps are dynamic in nature, it is impossible to understand, monitor, and update lifetime predictions without understanding the dynamics of cap degradation, which is most often due to multiple interdependent factors rather than isolated independent events. In an attempt to understand the dynamics of cap degradation, a computer model using system dynamics is being developed to capture the complex behavior of an evapotranspiration cap. The specific objectives of this project are to capture the dynamic, nonlinear feedback loop structures underlying an evapotranspiration cap and, through computer simulation, gain a better understanding of long-term behavior, influencing factors, and, ultimately, long-term cap performance.

  16. Indoleacetic acid movement in the root cap.

    PubMed

    Pernet, J J; Pilet, P E

    1976-01-01

    When applied on the root cap of Zea mays L., indol-3yl-acetic acid (IAA) may enter the root tip and move basipetally inside the cap. From the cap to the apex (quiescent centre and meristem) the IAA transport is very slow. Polarity of IAA movement, in relation to growth, is discussed.

  17. 21 CFR 888.3000 - Bone cap.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Bone cap. 888.3000 Section 888.3000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3000 Bone cap. (a) Identification. A bone cap is a...

  18. 21 CFR 888.3000 - Bone cap.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Bone cap. 888.3000 Section 888.3000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3000 Bone cap. (a) Identification. A bone cap is a...

  19. 21 CFR 888.3000 - Bone cap.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Bone cap. 888.3000 Section 888.3000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3000 Bone cap. (a) Identification. A bone cap is a...

  20. 47 CFR 54.507 - Cap.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... schools and libraries support mechanism in accordance with the public interest and notwithstanding the... schools and libraries mechanism in accordance with the public interest and notwithstanding the annual cap... Universal Service Support for Schools and Libraries § 54.507 Cap. (a) Amount of the annual cap. In...

  1. 47 CFR 54.507 - Cap.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... schools and libraries support mechanism in accordance with the public interest and notwithstanding the... schools and libraries mechanism in accordance with the public interest and notwithstanding the annual cap... Universal Service Support for Schools and Libraries § 54.507 Cap. (a) Amount of the annual cap. In...

  2. 21 CFR 888.3000 - Bone cap.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bone cap. 888.3000 Section 888.3000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3000 Bone cap. (a) Identification. A bone cap is a...

  3. 21 CFR 884.5250 - Cervical cap.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cervical cap. 884.5250 Section 884.5250 Food and... OBSTETRICAL AND GYNECOLOGICAL DEVICES Obstetrical and Gynecological Therapeutic Devices § 884.5250 Cervical cap. (a) Identification. A cervical cap is a flexible cuplike receptacle that fits over the cervix...

  4. 21 CFR 884.5250 - Cervical cap.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cervical cap. 884.5250 Section 884.5250 Food and... OBSTETRICAL AND GYNECOLOGICAL DEVICES Obstetrical and Gynecological Therapeutic Devices § 884.5250 Cervical cap. (a) Identification. A cervical cap is a flexible cuplike receptacle that fits over the cervix...

  5. 21 CFR 884.5250 - Cervical cap.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cervical cap. 884.5250 Section 884.5250 Food and... OBSTETRICAL AND GYNECOLOGICAL DEVICES Obstetrical and Gynecological Therapeutic Devices § 884.5250 Cervical cap. (a) Identification. A cervical cap is a flexible cuplike receptacle that fits over the cervix...

  6. 21 CFR 884.5250 - Cervical cap.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cervical cap. 884.5250 Section 884.5250 Food and... OBSTETRICAL AND GYNECOLOGICAL DEVICES Obstetrical and Gynecological Therapeutic Devices § 884.5250 Cervical cap. (a) Identification. A cervical cap is a flexible cuplike receptacle that fits over the cervix...

  7. Helix Capping in RNA Structure

    PubMed Central

    Lee, Jung C.; Gutell, Robin R.

    2014-01-01

    Helices are an essential element in defining the three-dimensional architecture of structured RNAs. While internal basepairs in a canonical helix stack on both sides, the ends of the helix stack on only one side and are exposed to the loop side, thus susceptible to fraying unless they are protected. While coaxial stacking has long been known to stabilize helix ends by directly stacking two canonical helices coaxially, based on analysis of helix-loop junctions in RNA crystal structures, herein we describe helix capping, topological stacking of a helix end with a basepair or an unpaired nucleotide from the loop side, which in turn protects helix ends. Beyond the topological protection of helix ends against fraying, helix capping should confer greater stability onto the resulting composite helices. Our analysis also reveals that this general motif is associated with the formation of tertiary structure interactions. Greater knowledge about the dynamics at the helix-junctions in the secondary structure should enhance the prediction of RNA secondary structure with a richer set of energetic rules and help better understand the folding of a secondary structure into its three-dimensional structure. These together suggest that helix capping likely play a fundamental role in driving RNA folding. PMID:24691270

  8. Phytoremediation -- a practical capping alternative

    SciTech Connect

    Beath, J.M.; Peak, M.J.

    1997-12-31

    Much literature has been devoted recently to the use of various plant species for the uptake of heavy metals and organic contaminants. Other uses for plants as part of the remediation process are growing in perceived effectiveness. Consequently, this paper deals with two other equally important potential uses of plants to address environmental problems that are just now evolving to the field trial stage: the use of plants to remediate organic pollutants; and the use of plants to control the rainfall-driven leaching of contaminants and the subsequent delivery to underlying groundwater. The traditional Resource Conservation and Recovery Act (RCRA) approach to capping landfills will be contrasted with the potential benefits of using plants that can balance incoming rainfall with evapotranspiration, as well as plants which can act on organic constituents in soil or sludge by either uptake or by promoting microbial activity in soil. This paper compares traditional RCRA capping costs to those for a phytoremediation capping alternative, whose benefits include significantly lower implementation cost and continued remediation. This paper discusses important elements of a successful approach to phytoremediation including: species selection, implementation techniques, cost-efficient monitoring, regulatory aspects, project timing, and realistic expectations.

  9. Structure of acetylcholine receptor dimer determined by neutron scattering and electron microscopy

    SciTech Connect

    Wise, D.S.; Schoenborn, B.P.; Karlin, A.

    1981-04-10

    Previous work has shown that the predominant native form of the acetylcholine receptor from the electric tissue of Torpedo californica is a dimer of M/sub r/ = 500,000, cross-linked by a disulfide bond between the largest (delta) of the five chains (..cap alpha../sub 2/..beta gamma..delta) that comprise the monomer. Small-angle neutron scattering of purified receptor dimer in Triton X-100 solution containing 18% D/sub 2/O, in which the Triton X-100 is contrast-matched, yields a radius of gyration of the dimer of 66 A. Based on the assumptions that the dimer is symmetrical and that the radius of gyration of the monomer does not change in forming dimer, this value, together with the radius of gyration of the receptor monomer (46 A), determined previously, allows the calculation of the distance separating the centers of neutron scattering density of monomers in a dimer; the result is 96 A. Electron microscopy of negatively stained dimers permits an independent measurement of the distance between the apparent centers of mass of the monomers; the average is 96 A, in agreement with the result of the neutron scattering analysis. The electron micrographs of dimer also permit the location of the delta chains at the region of contact of the monomers. A model for the receptor dimer consistent with all available structural information is presented.

  10. Application of alpha spectrometry to the discovery of new elements by heavy-ion-beam bombardment

    SciTech Connect

    Nitschke, J.M.

    1983-05-01

    Starting with polonium in 1898, ..cap alpha..-spectrometry has played a decisive role in the discovery of new, heavy elements. For even-even nuclei, ..cap alpha..-spectra have proved simple to interpret and exhibit systematic trends that allow extrapolation to unknown isotopes. The early discovery of the natural ..cap alpha..-decay series led to the very powerful method of genetically linking the decay of new elements to the well-established ..cap alpha..-emission of daughter and granddaughter nuclei. This technique has been used for all recent discoveries of new elements including Z = 109. Up to mendelevium (Z = 101), thin samples suitable for ..cap alpha..-spectrometry were prepared by chemical methods. With the advent of heavy-ion accelerators new sample preparation methods emerged. These were based on the large momentum transfer associated with heavy-ion reactions, which produced energetic target recoils that, when ejected from the target, could be thermalized in He gas. Subsequent electrical deposition or a He-jet technique yielded samples that were not only thin enough for ..cap alpha..-spectroscopy, but also for ..cap alpha..- and ..beta..-recoil experiments. Many variations of these methods have been developed and are discussed. For the synthesis of element 106 an aerosol-based recoil transport technique was devised. In the most recent experiments, ..cap alpha..-spectrometry has been coupled with the magnetic analysis of the recoils. The time from production to analysis of an isotope has thereby been reduced to 10/sup -6/ s; while it was 10/sup -1/ to 10/sup 0/ s for He-jets and 10/sup 1/ to 10/sup 3/ s for rapid chemical separations. Experiments are now in progress to synthesize super heavy elements (SHE) and to analyze them with these latest techniques. Again, ..cap alpha..-spectrometry will play a major role since the expected signature for the decay of a SHE is a sequence of ..cap alpha..-decays followed by spontaneous fission.

  11. Neutron total and scattering cross sections of /sup 6/Li in the few MeV region

    SciTech Connect

    Smith, A.; Guenther, P.; Whalen, J.

    1980-02-01

    Neutron total cross sections of /sup 6/Li are measured from approx. 0.5 to approx. 4.8 MeV at intervals of approx.< 10 keV. Neutron differential elastic-scattering cross sections are measured from 1.5 to 4.0 MeV at approx.> 10 scattering angles and at incident-neutron intervals of approx.< 100 keV. Neutron differential inelastic-scattering cross sections are measured in the incident-energy range 3.5 to 4.0 MeV. The experimental results are extended to lower energies using measured neutron total cross sections recently reported elsewhere by the authors. The composite experimental data (total cross sections from 0.1 to 4.8 MeV and scattering cross sections from 0.22 to 4.0 MeV) are interpreted in terms of a simple two-level R-matrix model which describes the observed cross sections and implies the reaction cross section in unobserved channels; notably the (n;..cap alpha..)t reaction (Q = 4.783 MeV). The experimental and calculational results are compared with previously reported results as summarized in the ENDF/B-V evaluated nuclear data file.

  12. Relationship between cap structure and energy gap in capped carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Ono, Shota; Tanikawa, Kousei; Kuwahara, Riichi; Ohno, Kaoru

    2016-07-01

    Revealing a universal relation between geometrical structures and electronic properties of capped carbon nanotubes (CNTs) is one of the current objectives in nanocarbon community. Here, we investigate the local curvature of capped CNTs and define the cap region by a crossover behavior of the curvature energy versus the number of carbon atoms integrated from the tip to the tube region. Clear correlations among the energy gap of the cap localized states, the curvature energy, the number of carbon atoms in the cap region, and the number of specific carbon clusters are observed. The present analysis opens the way to understand the cap states.

  13. Relationship between cap structure and energy gap in capped carbon nanotubes.

    PubMed

    Ono, Shota; Tanikawa, Kousei; Kuwahara, Riichi; Ohno, Kaoru

    2016-07-14

    Revealing a universal relation between geometrical structures and electronic properties of capped carbon nanotubes (CNTs) is one of the current objectives in nanocarbon community. Here, we investigate the local curvature of capped CNTs and define the cap region by a crossover behavior of the curvature energy versus the number of carbon atoms integrated from the tip to the tube region. Clear correlations among the energy gap of the cap localized states, the curvature energy, the number of carbon atoms in the cap region, and the number of specific carbon clusters are observed. The present analysis opens the way to understand the cap states. PMID:27421422

  14. Polar cap auroral arcs: Observations, theories, and a numerical model. Ph.D. Thesis

    SciTech Connect

    Berg, G.A.

    1993-01-01

    This thesis reports the results of probably the most completely documented study of auroras near the polar cap boundary performed to date. Three fully instrumented rockets flew into the morning sector of the polar cap, complemented on the ground by a digital all-sky camera and incoherent scatter radar. Additionally, DMSP satellite passes over the polar cap bracketed the launches. The authors use these data to address two main issues: (1) the relationship between the state of the magnetosphere and the formation of polar cap arcs, and (2) the character of the current systems associated with polar cap arcs. The data indicate that in a decaying magnetosphere sun-aligned arcs erupt into the polar cap at high velocity from regions of enhanced brightness in the auroral oval. Two bright polar cap arcs formed in this manner in the region sampled by the rockets. The most equatorward of the arcs, sampled by two of the rockets during its lifetime, erupted into a region already characterized by strong sunward convection. The most poleward, however, which formed after the rockets had passed, pushed into a region where anti-sunward convection pertained less than two minutes earlier. It is likely that the boundary between sunward and anti-sunward convection shifted poleward so that sunward convection pertained at this arc as well. The formation of polar cap arcs may be tied closely to the reconfiguration of the magnetosphere into a system characterized by a smaller polar cap. One of the payloads measured, with high resolution, both E and delta B as well as energetic particle flux. This permitted an in-depth study of the current systems flown through. The correlation between delta E and delta B is classic, both fields indicating upward field-aligned currents in virtually every region of enhanced electron precipitation. However, the currents deduced from the electrons do not agree in magnitude with those deduced from the fields.

  15. Giant Resonances in the Alpha-Nucleus Interaction

    SciTech Connect

    Karpeshin, F. F.

    2010-04-30

    Tunneling of alpha particles through the Coulomb barrier for the source {sup 135}Pr nucleus is consecutively considered. The effect of sharp peaks arising in the case of coincidence of the alpha energy with that of a quasistationary state within the barrier is elucidated. Peaks' energy depend on the alpha-nucleus potential. They can give rise to 'anomalous' properties of some neutron resonances. The peaks can also be observed in the incoming alpha-nucleus channel. The method can be applied for solution of the reverse problem of the alpha-nucleus scattering.

  16. Mountain Glaciers and Ice Caps

    USGS Publications Warehouse

    Ananichheva, Maria; Arendt, Anthony; Hagen, Jon-Ove; Hock, Regine; Josberger, Edward G.; Moore, R. Dan; Pfeffer, William Tad; Wolken, Gabriel J.

    2011-01-01

    Projections of future rates of mass loss from mountain glaciers and ice caps in the Arctic focus primarily on projections of changes in the surface mass balance. Current models are not yet capable of making realistic forecasts of changes in losses by calving. Surface mass balance models are forced with downscaled output from climate models driven by forcing scenarios that make assumptions about the future rate of growth of atmospheric greenhouse gas concentrations. Thus, mass loss projections vary considerably, depending on the forcing scenario used and the climate model from which climate projections are derived. A new study in which a surface mass balance model is driven by output from ten general circulation models (GCMs) forced by the IPCC (Intergovernmental Panel on Climate Change) A1B emissions scenario yields estimates of total mass loss of between 51 and 136 mm sea-level equivalent (SLE) (or 13% to 36% of current glacier volume) by 2100. This implies that there will still be substantial glacier mass in the Arctic in 2100 and that Arctic mountain glaciers and ice caps will continue to influence global sea-level change well into the 22nd century.

  17. Rapid surface enhanced Raman scattering detection method for chloramphenicol residues.

    PubMed

    Ji, Wei; Yao, Weirong

    2015-06-01

    Chloramphenicol (CAP) is a widely used amide alcohol antibiotics, which has been banned from using in food producing animals in many countries. In this study, surface enhanced Raman scattering (SERS) coupled with gold colloidal nanoparticles was used for the rapid analysis of CAP. Density functional theory (DFT) calculations were conducted with Gaussian 03 at the B3LYP level using the 3-21G(d) and 6-31G(d) basis sets to analyze the assignment of vibrations. Affirmatively, the theoretical Raman spectrum of CAP was in complete agreement with the experimental spectrum. They both exhibited three strong peaks characteristic of CAP at 1104 cm(-1), 1344 cm(-1), 1596 cm(-1), which were used for rapid qualitative analysis of CAP residues in food samples. The use of SERS as a method for the measurements of CAP was explored by comparing use of different solvents, gold colloidal nanoparticles concentration and absorption time. The method of the detection limit was determined as 0.1 μg/mL using optimum conditions. The Raman peak at 1344 cm(-1) was used as the index for quantitative analysis of CAP in food samples, with a linear correlation of R(2)=0.9802. Quantitative analysis of CAP residues in foods revealed that the SERS technique with gold colloidal nanoparticles was sensitive and of a good stability and linear correlation, and suited for rapid analysis of CAP residue in a variety of food samples. PMID:25754387

  18. Rapid surface enhanced Raman scattering detection method for chloramphenicol residues

    NASA Astrophysics Data System (ADS)

    Ji, Wei; Yao, Weirong

    2015-06-01

    Chloramphenicol (CAP) is a widely used amide alcohol antibiotics, which has been banned from using in food producing animals in many countries. In this study, surface enhanced Raman scattering (SERS) coupled with gold colloidal nanoparticles was used for the rapid analysis of CAP. Density functional theory (DFT) calculations were conducted with Gaussian 03 at the B3LYP level using the 3-21G(d) and 6-31G(d) basis sets to analyze the assignment of vibrations. Affirmatively, the theoretical Raman spectrum of CAP was in complete agreement with the experimental spectrum. They both exhibited three strong peaks characteristic of CAP at 1104 cm-1, 1344 cm-1, 1596 cm-1, which were used for rapid qualitative analysis of CAP residues in food samples. The use of SERS as a method for the measurements of CAP was explored by comparing use of different solvents, gold colloidal nanoparticles concentration and absorption time. The method of the detection limit was determined as 0.1 μg/mL using optimum conditions. The Raman peak at 1344 cm-1 was used as the index for quantitative analysis of CAP in food samples, with a linear correlation of R2 = 0.9802. Quantitative analysis of CAP residues in foods revealed that the SERS technique with gold colloidal nanoparticles was sensitive and of a good stability and linear correlation, and suited for rapid analysis of CAP residue in a variety of food samples.

  19. Additional {alpha}-particle optical potential tests below the Coulomb barrier

    SciTech Connect

    Avrigeanu, M.; Avrigeanu, V.

    2010-03-15

    New results of ({alpha},{gamma}) and ({alpha},n) reaction cross section measurements close to the reaction thresholds support the setting up of recent parameters of the {alpha}-particle optical model potential (OMP) below the Coulomb barrier. Particular features of the {alpha}-particle optical potential at energies below the Coulomb barrier explain the failure of using the OMP parameters obtained by analysis of only {alpha}-particle elastic scattering at higher energies.

  20. Alpha-adrenergic regulation of angiotensin II receptors in neuronal cultures from rat brain

    SciTech Connect

    Sumners, C.; Watkins, L.L.; Raizada, M.K.

    1986-03-05

    Our previous studies have suggested that endogenous catecholamine (CA) levels are important regulators of angiotensin II receptors (AngII-R) in neuronal cultures. The present study was undertaken to determine the possible mechanisms by which CA exert their effects on AngII-R. Incubation of neuronal cultures with norepinephrine (NE) resulted in time and dose dependent decreases in (/sup 125/I)-AngII specific binding. A maximal effect of 60-70% was observed between 4-8 hours at 1..mu..M NE, which was the result of a decrease in Bmax (104 +/- 16.3 fmol/mg protein in controls vs 41.4 +/- 9.3 fmol/mg protein in NE treated) and little change in Kd. Similar effects were observed when neuronal cultures were incubated with dopamine (DA) or phenylephrine, but serotonin, epinephrine and isoproterenol had no effect. The NE and DA stimulated decrease in AngII-R appears to be an ..cap alpha../sub 1/=adrenergic receptor mediated phenomenon because it is abolished by coincubation with prazosin (..cap alpha../sub 1/-antagonist) and not by ..cap alpha../sub 2/- or ..beta..-antagonists. Similar incubations of neuronal cultures with NE also caused a time and dose dependent downregulation of ..cap alpha../sub 1/-adrenergic receptors. Taken together these observations indicate that the NE induced downregulation of AngII-R is mediated by ..cap alpha../sub 1/-receptors, and suggest that one possible mechanism may be the cointernalization of both ..cap alpha../sub 1/- and AngII-R stimulated by ..cap alpha../sub 1/-adrenergic agonists.

  1. Alpha-1 Antitrypsin Deficiency

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Alpha-1 Antitrypsin Deficiency? Alpha-1 antitrypsin (an-tee-TRIP-sin) deficiency, or AAT ... as it relates to lung disease. Overview Alpha-1 antitrypsin, also called AAT, is a protein made ...

  2. Glutathione-capped CdTe nanocrystals as probe for the determination of fenbendazole.

    PubMed

    Li, Qin; Tan, Xuanping; Li, Jin; Pan, Li; Liu, Xiaorong

    2015-04-15

    Water-soluble glutathione (GSH)-capped CdTe quantum dots (QDs) were synthesized. In pH 7.1 PBS buffer solution, the interaction between GSH-capped CdTe QDs and fenbendazole (FBZ) was investigated by spectroscopic methods, including fluorescence spectroscopy, ultraviolet-visible absorption spectroscopy, and resonance Rayleigh scattering (RRS) spectroscopy. In GSH-capped CdTe QDs solution, the addition of FBZ results in the fluorescence quenching and RRS enhancement of GSH-capped CdTe QDs. And the quenching intensity (enhanced RRS intensity) was proportional to the concentration of FBZ in a certain range. Investigation of the interaction mechanism, proved that the fluorescence quenching and RRS enhancement of GSH-capped CdTe QDs by FBZ is the result of electrostatic attraction. Based on the quenching of fluorescence (enhancement of RRS) of GSH-capped CdTe QDs by FBZ, a novel, simple, rapid and specific method for FBZ determination was proposed. The detection limit for FBZ was 42 ng mL(-1) (3.4 ng mL(-1)) and the quantitative determination range was 0-2.8 μg mL(-1) with a correlation of 0.9985 (0.9979). The method has been applied to detect FBZ in real simples and with satisfactory results.

  3. Glutathione-capped CdTe nanocrystals as probe for the determination of fenbendazole

    NASA Astrophysics Data System (ADS)

    Li, Qin; Tan, Xuanping; Li, Jin; Pan, Li; Liu, Xiaorong

    2015-04-01

    Water-soluble glutathione (GSH)-capped CdTe quantum dots (QDs) were synthesized. In pH 7.1 PBS buffer solution, the interaction between GSH-capped CdTe QDs and fenbendazole (FBZ) was investigated by spectroscopic methods, including fluorescence spectroscopy, ultraviolet-visible absorption spectroscopy, and resonance Rayleigh scattering (RRS) spectroscopy. In GSH-capped CdTe QDs solution, the addition of FBZ results in the fluorescence quenching and RRS enhancement of GSH-capped CdTe QDs. And the quenching intensity (enhanced RRS intensity) was proportional to the concentration of FBZ in a certain range. Investigation of the interaction mechanism, proved that the fluorescence quenching and RRS enhancement of GSH-capped CdTe QDs by FBZ is the result of electrostatic attraction. Based on the quenching of fluorescence (enhancement of RRS) of GSH-capped CdTe QDs by FBZ, a novel, simple, rapid and specific method for FBZ determination was proposed. The detection limit for FBZ was 42 ng mL-1 (3.4 ng mL-1) and the quantitative determination range was 0-2.8 μg mL-1 with a correlation of 0.9985 (0.9979). The method has been applied to detect FBZ in real simples and with satisfactory results.

  4. Laser rods with undoped, flanged end-caps for end-pumped laser applications

    DOEpatents

    Meissner, H.E.; Beach, R.J.; Bibeau, C.; Sutton, S.B.; Mitchell, S.; Bass, I.; Honea, E.

    1999-08-10

    A method and apparatus for achieving improved performance in a solid state laser is provided. A flanged, at least partially undoped end-cap is attached to at least one end of a laserable medium. Preferably flanged, undoped end-caps are attached to both ends of the laserable medium. Due to the low scatter requirements for the interface between the end-caps and the laser rod, a non-adhesive method of bonding is utilized such as optical contacting combined with a subsequent heat treatment of the optically contacted composite. The non-bonded end surfaces of the flanged end-caps are coated with laser cavity coatings appropriate for the lasing wavelength of the laser rod. A cooling jacket, sealably coupled to the flanged end-caps, surrounds the entire length of the laserable medium. Radiation from a pump source is focused by a lens duct and passed through at least one flanged end-cap into the laser rod. 14 figs.

  5. Some photometric properties of the Martian south polar cap region during the 1971 apparition

    NASA Technical Reports Server (NTRS)

    Lumme, K.; James, P. B.

    1984-01-01

    High-quality earth-based photographs from the Lowell Observatory Planetary Research Center collection have been analyzed to derive some photometric parameters for the Martian south polar cap region during the 1971 apparition. The optical thickness of the atmosphere above the cap varied with wavelength from 0.35 + or - 0.05 in red light to 0.58 + or 0.06 in UV light. The effective geometric albedo is calculated from the 30 deg phase data assuming isotropic scattering: it varies from 0.85 + or - 0.04 (in red light) to 0.63 + or 0.05 (in UV light).

  6. Alpha decay self-damage in cubic and monoclinic zirconolite

    SciTech Connect

    Clinard, F.W. Jr.; Land, C.C.; Peterson, D.E.; Rohr, D.L.; Roof, R.B.

    1981-01-01

    Samples of primarily-monoclinic /sup 238/Pu-doped zirconolite were stored at ambient temperature to allow accumulation of alpha decay self-damage to a dose of 1 x 10/sup 24/ ..cap alpha../m/sup 3/ (equivalent to a SYNROC age of approx. 10/sup 3/y). Bulk swelling reached 2.3 vol% with no tendency toward saturation, a damage response similar to that observed for cubic Pu-doped zirconolite. X-ray volumetric swelling at 4 x 10/sup 24/ ..cap alpha../m/sup 3/ was 1 vol%, considerably less than that for the cubic material. Changes in cell dimensions differed significantly from those reported by others for a monoclinic natural mineral. Extensive microcracking was observed, and is attributed at least partially to swelling differences between the matrix and minor phases.

  7. Small angle elastic scattering of protons off of spinless nuclei

    SciTech Connect

    Ling, A.G.

    1988-07-01

    Elastic differential cross sections and analyzing powers for 800 MeV protons incident on /sup 12/C, /sup 40/Ca, and /sup 208/Pb in the momentum transfer range 20 MeV/c < q < 130 MeV/c have been measured. The data was taken with the High Resolution Spectrometer (HRS) at the Los Alamos Meson Physics Facility. Special delay-line drift chambers with dead regions for the beam to pass through them were used to obtain the data. Through the interference of the Coulomb and nuclear contributions to the differential cross section in the small angle region, the ratio of the real to imaginary part of the forward nuclear amplitude ..cap alpha../sub n/(0) = Ref/sub n/(0)/Imf/sub n/(0) is extracted. The importance of knowing this quantity at lower energies in order to study the differences between relativistic and non-relativistic scattering theories is discussed. 130 refs., 60 figs., 12 tabs.

  8. Postsynaptic alpha-adrenoceptors, calcium mobilization and (/sup 3/H), 4-dihydropyridine binding in vascular smooth muscle of rat tail artery

    SciTech Connect

    Su, C.M.

    1985-01-01

    Pharmacologic characterization of post-synaptic ..cap alpha..-adrenoceptors in rat tail artery was examined by using selective agonists and antagonists. In this tissue, the ..cap alpha..-adrenoceptor agonists employed all produced concentration-dependent mechanical responses with rank order of potency, clonidine > norepinephrine > norepinephrine > phenylephrine > UK > 14304 > B-HT 920. This order of agonists activities not consistent with a simple classification into ..cap alpha../sub 1/- and ..cap alpha../sub 2/-adrenoceptors in the rat tail artery. Antagonism by prazosin and yohimbine of phenylephrine, norepinephrine and clonidine responses did not reveal the anticipated discrimination between ..cap alpha../sub 1/- and ..cap alpha../sub 2/-adrenoceptors. Potassium depolarization-induced responses were very sensitive to antagonism by the Ca/sup 2 +/ antagonists nifedipine and D 600. The sensitivity sequence of ..cap alpha..-adrenoceptor agonist induced responses to nifedipine and D 600 is H-HT 920 (> clonidine) > phenylephrine > norepinephrine. This disagrees with the thesis that ..cap alpha../sub 2/-adrenoceptor mediated responses in vascular smooth muscle are more sensitive than are ..cap alpha../sub 1/-adrenoceptor mediated responses to Ca/sup 2 +/ channel antagonists. Radioligand binding studies of (/sup 3/H)nitrendipine and (/sup 3/H)Bay K 8644 to microsomal preparations of tail artery membrane a single set of high affinity binding sites and there is a good correlation between the pharmacological potencies and binding affinities of these agents. In addition, study of the displacement of (/sup 3/H)nitrendipine by Bay K 8644 revealed IC/sub 50/ and K/sub l/ values which are in approximate accord with those determined for pharmacologic experiments.

  9. CAPS Capsule. Volume 5, Number 1.

    ERIC Educational Resources Information Center

    Walz, Garry, Ed.; And Others

    Published 3 times yearly by the ERIC Clearinghouse on Counseling and Personnel Services, CAPS Capsule acquaints the reader with recent projects, meetings, publications and materials which are of interest to those in the helping professions. This issue introduces several new publications offered by CAPS under the name, "The Counselor's S x-Pack."…

  10. 31 CFR 50.15 - Cap disclosure.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false Cap disclosure. 50.15 Section 50.15 Money and Finance: Treasury Office of the Secretary of the Treasury TERRORISM RISK INSURANCE PROGRAM Disclosures as Conditions for Federal Payment § 50.15 Cap disclosure. (a) General. Under section 103(e)(2)...

  11. 31 CFR 50.15 - Cap disclosure.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false Cap disclosure. 50.15 Section 50.15 Money and Finance: Treasury Office of the Secretary of the Treasury TERRORISM RISK INSURANCE PROGRAM Disclosures as Conditions for Federal Payment § 50.15 Cap disclosure. (a) General. Under section 103(e)(2)...

  12. 31 CFR 50.15 - Cap disclosure.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Cap disclosure. 50.15 Section 50.15 Money and Finance: Treasury Office of the Secretary of the Treasury TERRORISM RISK INSURANCE PROGRAM Disclosures as Conditions for Federal Payment § 50.15 Cap disclosure. (a) General. Under section 103(e)(2)...

  13. 31 CFR 50.15 - Cap disclosure.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance: Treasury 1 2012-07-01 2012-07-01 false Cap disclosure. 50.15 Section 50.15 Money and Finance: Treasury Office of the Secretary of the Treasury TERRORISM RISK INSURANCE PROGRAM Disclosures as Conditions for Federal Payment § 50.15 Cap disclosure. (a) General. Under section 103(e)(2)...

  14. 31 CFR 50.15 - Cap disclosure.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Cap disclosure. 50.15 Section 50.15 Money and Finance: Treasury Office of the Secretary of the Treasury TERRORISM RISK INSURANCE PROGRAM Disclosures as Conditions for Federal Payment § 50.15 Cap disclosure. (a) General. Under section 103(e)(2)...

  15. Purification and Biophysical Characterization of the CapA Membrane Protein FTT0807 from Francisella tularensis

    PubMed Central

    2015-01-01

    The capA gene (FTT0807) from Francisella tularensis subsp. tularensis SCHU S4 encodes a 44.4 kDa integral membrane protein composed of 403 amino acid residues that is part of an apparent operon that encodes at least two other membrane proteins, CapB, and CapC, which together play a critical role in the virulence and pathogenesis of this bacterium. The capA gene was overexpressed in Escherichia coli as a C-terminal His6-tagged fusion with a folding reporter green fluorescent protein (frGFP). Purification procedures using several detergents were developed for the fluorescing and membrane-bound product, yielding approximately 30 mg of pure protein per liter of bacterial culture. Dynamic light scattering indicated that CapA-frGFP was highly monodisperse, with a size that was dependent upon both the concentration and choice of detergent. Circular dichroism showed that CapA-frGFP was stable over the range of 3–9 for the pH, with approximately half of the protein having well-defined α-helical and β-sheet secondary structure. The addition of either sodium chloride or calcium chloride at concentrations producing ionic strengths above 0.1 M resulted in a small increase of the α-helical content and a corresponding decrease in the random-coil content. Secondary-structure predictions on the basis of the analysis of the sequence indicate that the CapA membrane protein has two transmembrane helices with a substantial hydrophilic domain. The hydrophilic domain is predicted to contain a long disordered region of 50–60 residues, suggesting that the increase of α-helical content at high ionic strength could arise because of electrostatic interactions involving the disordered region. CapA is shown to be an inner-membrane protein and is predicted to play a key cellular role in the assembly of polysaccharides. PMID:24593131

  16. Determination of alpha/sub s/ from energy-energy correlations in e/sup +/e/sup -/ annihilation at 29 GeV

    SciTech Connect

    Wood, D.R.

    1987-10-01

    We have studied the energy-energy correlation in e/sup +/e/sup -/ annihilation into hadrons at ..sqrt..s = 29 GeV using the Mark II detector at PEP. We find to O(..cap alpha../sub s//sup 2/) that ..cap alpha../sub s/ = 0.158 +- .003 +- .008 if hadronization is described by string fragmentation. Independent fragmentation schemes give ..cap alpha../sub s/ = .10 - .14, and give poor agreement with the data. A leading-log shower fragmentation model is found to describe the data well.

  17. Creatine kinase and alpha-actin mRNA levels decrease in diabetic rat hearts

    SciTech Connect

    Popovich, B.; Barrieux, A.; Dillmann, W.H.

    1987-05-01

    Diabetic cardiomyopathy is associated with cardiac atrophy and isoenzyme redistribution. To determine if tissue specific changes occur in mRNAs coding for ..cap alpha..-actin and creatine kinase (CK), they performed RNA blot analysis. Total ventricular RNA from control (C) and 4 wk old diabetic (D) rats were hybridized with /sup 32/P cDNA probes for ..cap alpha..-actin and CK. A tissue independent cDNA probe, CHOA was also used. Signal intensity was quantified by photodensitometry. D CK mRNA was 47 +/- 16% lower in D vs C. Insulin increases CK mRNA by 20% at 1.5 hs, and completely reverses the deficit after 4 wks. D ..cap alpha..-actin mRNA is 66 +/- 18% lower in D vs C. Insulin normalized ..cap alpha..-actin mRNA by 5 hs. CHOA mRNA is unchanged in D vs C, but D + insulin CHOA mRNA is 30 +/- 2% lower than C. In rats with diabetic cardiomyopathy, muscle specific CK and ..cap alpha..-actin mRNAs are decreased. Insulin treatment reverses these changes.

  18. Alpha-irradiation-induced G2 delay: a period of cell recovery

    SciTech Connect

    Lucke-Huhle, C.

    1982-02-01

    Exponentially growing Chinese hamster V79 cells were delayed in G2 very efficiently by 3.4-MeV ..cap alpha.. particles. In comparison with the effect caused by sparsely ionizing /sup 60/Co ..gamma.. rays, G2 delay after ..cap alpha.. irradiation was greater by a factor of 6.7 and 4.2 for doses <0.5 Gy and >0.5 Gy, respectively, if the slopes of the dose-effect curves are compared. While at low doses (0.03-0.5 Gy) G2 arrest was reversible within 10 hr, increasing doses (0.5-4.38 Gy) of ..cap alpha.. irradiation blocked increasing fractions of cells for more than 16 hr, as determined by flow cytometry, and only some of these were able to complete mitosis. Addition of caffeine, however, reduced G2 arrest considerably if given directly after irradiation and reversed G2 arrest if added 8 hr after 4.38 Gy of ..cap alpha.. particles, a time when most of the cells already had accumulated in G2, caffeine treatment during G2 decreased survival after ..cap alpha.. irradiation by factors of 1.3 and 1.7 for 1 and 2 mM caffeine, respectively.

  19. A model for the disc Lyman alpha emission of Uranus

    SciTech Connect

    Jaffel, L.B.; Vidal-Madjar, A. ); Prange, R.; Emerich, C. ); McConnell, J.C. )

    1991-06-01

    A new efficient radiative transfer algorithm for inhomogeneous atmospheres has been used to simulate the limb to limb Lyman {alpha} reflectivities observed with the Voyager ultraviolet spectrometer during the flyby of Uranus. It was shown that complete frequency redistribution should be adequate to describe the disc emissions. The model atmosphere used was derived using a combination of Voyager measurements and modeling. Atomic H densities calculated had sources derivable directly from solar FUV and EUV fluxes. To fit the observations, four contributions are evaluated: (1) the resonance scattering of solar Lyman {alpha} radiation, (2) Rayleigh-Raman scattering of solar Lyman {alpha} radiation, (3) the resonance scattering of interplanetary Lyman {alpha} radiation, and (4) a possible internal source of unknown origin. From comparison with the observations, and provided that the published Voyager calibrations are correct, it is shown that only atmospheres with low eddy diffusion coefficients (K{sub H}{le}100 cm{sup 2} s{sup {minus}1}) and an internal source could simulate both the shape and the strength of the measured disc emission. The main results are then that the direct solar Lyman {alpha} scattering contribution (type 1 plus type 2) is of the order of 760 R, the scattering of interplanetary Lyman {alpha} contributes about 320 R, and a small additional internal source providing about 100-500 R is needed to match the measurements. Further, the analysis of the disc intensities suggests that there is no strong variation of K with latitude.

  20. Model for Formation of Martian Residual Cap Depressions (Swiss Cheese)

    NASA Astrophysics Data System (ADS)

    Byrne, S.; Ingersoll, A. P.

    2001-12-01

    In an effort for explain the formation of the `Swiss-cheese' terrain visible on the southern residual cap of Mars (Thomas et al., Nature, 404,2000); we have developed a radiative model to follow the growth/decay of an initial depression due to sublimation/condensation of carbon dioxide. The pits making up this terrain have many distinctive features; they are shallow (~10m deep), with steep walls and flat floors and contain an interior moat that runs along the bottom of the walls. Their diameters range from a few 10's of meters to a kilometer. The model accounts for incident sunlight, emitted thermal radiation, and scattered short and long wave radiation. We have included the effects of a layer of water ice placed under the carbon dioxide at adjustable depth. The water ice layer is free to store heat during the summer (when the carbon dioxide has been removed) through subsurface diffusion of heat. Release of this heat at the end of the summer can inhibit frost formation. We have investigated many cases involving pure dry ice with constant albedo, albedo as a function of insolation, and differing albedo for fresh and residual frost (the latter has lower albedo). In most cases the initial depressions heal themselves and disappear into the surrounding terrain. Cases involving the layer of water ice provide a much closer approximation to the shape of the observed features (especially the flat bottoms). A problem arises of how much exposed water ice we can have during the summer season and still have temperatures averaged over the footprint of the Thermal Emission Spectrometer be close to the carbon dioxide sublimation temperatures. The depth to the water ice layer is a strong controlling factor of the evolution of depression shape and depth in our model. Matching this shape with observations yields important information regarding the depth to any putative water ice layer within the residual cap itself. It is known from laboratory measurements that carbon dioxide is too

  1. Fourier spectra from exoplanets with polar caps and ocean glint

    NASA Astrophysics Data System (ADS)

    Visser, P. M.; van de Bult, F. J.

    2015-07-01

    Context. The weak orbital-phase dependent reflection signal of an exoplanet contains information on the planet surface, such as the distribution of continents and oceans on terrestrial planets. This light curve is usually studied in the time domain, but because the signal from a stationary surface is (quasi)periodic, analysis of the Fourier series may provide an alternative, complementary approach. Aims: We study Fourier spectra from reflected light curves for geometrically simple configurations. Depending on its atmospheric properties, a rotating planet in the habitable zone could have circular polar ice caps. Tidally locked planets, on the other hand, may have symmetric circular oceans facing the star. These cases are interesting because the high-albedo contrast at the sharp edges of the ice-sheets and the glint from the host star in the ocean may produce recognizable light curves with orbital periodicity, which could also be interpreted in the Fourier domain. Methods: We derive a simple general expression for the Fourier coefficients of a quasiperiodic light curve in terms of the albedo map of a Lambertian planet surface. Analytic expressions for light curves and their spectra are calculated for idealized situations, and dependence of the spectral peaks on the key parameters inclination, obliquity, and cap size is studied. Results: The ice-scattering and ocean glint contributions can be separated out, because the coefficients for glint are all positive, whereas ice sheets lead to even-numbered, higher harmonics. An in-view polar cap on a planet without axial tilt only produces a single peak. The special situation of edge-on observation, which is important for planets in transit, leads to the most pronounced spectral behavior. Then the respective spectra from planets with a circumventing ocean, a circular ocean (eyeball world), polar caps, and rings, have characteristic power-law tails n-2, n-7/2, n-4, and (-1)n + 1n-2. Conclusions: Promising recently discovered

  2. CAPS and INMS Major Accomplishments

    NASA Astrophysics Data System (ADS)

    Waite, J. Hunter

    2014-05-01

    The Cassini-Huygens Ion Neutral Mass Spectrometer (Cassini INMS) and the Cassini Plasma Spectrometer (CAPS) have provided "discovery" science at Titan, Enceladus, Rhea/Dione, and throughout the magnetosphere of Saturn during the course of the mission. In this talk we will review some of the major scientific achievements: 1) the discovery of an extremely complex ion neutral organic chemistry in Titan's upper atmosphere that forms the building blocks for aerosol processes below, 2) the discovery of gases and grains emanating from Enceladus' cryo-geysers that tell us about chemical processes in an interior sea, 3) the first direct compositional measurements of sputtered icy moon surfaces, 4) the clearest example to date of the complex plasma interchange processes that occur in rapidly rotating magnetospheres of gas giants, initiating global dynamic processes that enable Saturn to shed the plasma from Enceladus' plume, and complete with a myriad of longitudinal and solar local-time variations, and 5) the dominance of Enceladus water outgassing as a source of magnetospheric plasma that stretches out to Titan and provides oxygen that can convert Titan's rich nitrile populations into amino acids.

  3. Edge of polar cap patches

    NASA Astrophysics Data System (ADS)

    Hosokawa, K.; Taguchi, S.; Ogawa, Y.

    2016-04-01

    On the night of 4 December 2013, a sequence of polar cap patches was captured by an all-sky airglow imager (ASI) in Longyearbyen, Norway (78.1°N, 15.5°E). The 630.0 nm airglow images from the ASI of 4 second exposure time, oversampled the emission of natural lifetime (with quenching) of at least ˜30 sec, introduce no observational blurring effects. By using such high-quality ASI images, we succeeded in visualizing an asymmetry in the gradients between the leading/trailing edges of the patches in a 2-D fashion. The gradient in the leading edge was found to be 2-3 times steeper than that in the trailing edge. We also identified fingerlike structures, appearing only along the trailing edge of the patches, whose horizontal scale size ranged from 55 to 210 km. These fingers are considered to be manifestations of plasma structuring through the gradient-drift instability (GDI), which is known to occur only along the trailing edge of patches. That is, the current 2-D observations visualized, for the first time, how GDI stirs the patch plasma and such a mixing process makes the trailing edge more gradual. This result strongly implies a close connection between the GDI-driven plasma stirring and the asymmetry in the large-scale shape of patches and then suggests that the fingerlike structures can be used as markers to estimate the fine-scale structure in the plasma flow within patches.

  4. Genetic basis for the synthesis of the immunomodulatory mannose caps of lipoarabinomannan in Mycobacterium tuberculosis.

    PubMed

    Dinadayala, Premkumar; Kaur, Devinder; Berg, Stefan; Amin, Anita G; Vissa, Varalakshmi D; Chatterjee, Delphi; Brennan, Patrick J; Crick, Dean C

    2006-07-21

    Lipoarabinomannan (LAM) is a high molecular weight, heterogenous lipoglycan present in abundant quantities in Mycobacterium tuberculosis and many other actinomycetes. In M. tuberculosis, the non-reducing arabinan termini of the LAM are capped with alpha1-->2 mannose residues; in some other species, the arabinan of LAM is not capped or is capped with inositol phosphate. The nature and extent of this capping plays an important role in disease pathogenesis. MT1671 in M. tuberculosis CDC1551 was identified as a glycosyltransferase that could be involved in LAM capping. To determine the function of this protein a mutant strain of M. tuberculosis CDC1551 was studied, in which MT1671 was disrupted by transposition. SDS-PAGE analysis showed that the LAM of the mutant strain migrated more rapidly than that of the wild type and did not react with concanavalin A as did wild-type LAM. Structural analysis using NMR, gas chromatography/mass spectrometry, endoarabinanase digestion, Dionex high pH anion exchange chromatography, and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry demonstrated that the LAM of the mutant strain was devoid of mannose capping. Since an ortholog of MT1671 is not present in Mycobacterium smegmatis mc(2)155, a recombinant strain was constructed that expressed this protein. Analysis revealed that the LAM of the recombinant strain was larger than that of the wild type, had gained concanavalin A reactivity, and that the arabinan termini were capped with a single mannose residue. Thus, MT1671 is the mannosyltransferase involved in deposition of the first of the mannose residues on the non-reducing arabinan termini and the basis of much of the interaction between the tubercle bacillus and the host cell.

  5. The pharmaceutical vial capping process: Container closure systems, capping equipment, regulatory framework, and seal quality tests.

    PubMed

    Mathaes, Roman; Mahler, Hanns-Christian; Buettiker, Jean-Pierre; Roehl, Holger; Lam, Philippe; Brown, Helen; Luemkemann, Joerg; Adler, Michael; Huwyler, Joerg; Streubel, Alexander; Mohl, Silke

    2016-02-01

    Parenteral drug products are protected by appropriate primary packaging to protect against environmental factors, including potential microbial contamination during shelf life duration. The most commonly used CCS configuration for parenteral drug products is the glass vial, sealed with a rubber stopper and an aluminum crimp cap. In combination with an adequately designed and controlled aseptic fill/finish processes, a well-designed and characterized capping process is indispensable to ensure product quality and integrity and to minimize rejections during the manufacturing process. In this review, the health authority requirements and expectations related to container closure system quality and container closure integrity are summarized. The pharmaceutical vial, the rubber stopper, and the crimp cap are described. Different capping techniques are critically compared: The most common capping equipment with a rotating capping plate produces the lowest amount of particle. The strength and challenges of methods to control the capping process are discussed. The residual seal force method can characterize the capping process independent of the used capping equipment or CCS. We analyze the root causes of several cosmetic defects associated with the vial capping process.

  6. Tip cap for a turbine rotor blade

    DOEpatents

    Kimmel, Keith D

    2014-03-25

    A turbine rotor blade with a spar and shell construction, and a tip cap that includes a row of lugs extending from a bottom side that form dovetail grooves that engage with similar shaped lugs and grooves on a tip end of the spar to secure the tip cap to the spar against radial displacement. The lug on the trailing edge end of the tip cap is aligned perpendicular to a chordwise line of the blade in the trailing edge region in order to minimize stress due to the lugs wanting to bend under high centrifugal loads. A two piece tip cap with lugs at different angles will reduce the bending stress even more.

  7. The ATLAS TRT end-cap detectors

    NASA Astrophysics Data System (ADS)

    ATLAS TRT Collaboration; Abat, E.; Addy, T. N.; Åkesson, T. P. A.; Alison, J.; Anghinolfi, F.; Arik, E.; Arik, M.; Atoian, G.; Auerbach, B.; Baker, O. K.; Banas, E.; Baron, S.; Bault, C.; Becerici, N.; Beddall, A.; Beddall, A. J.; Bendotti, J.; Benjamin, D. P.; Bertelsen, H.; Bingul, A.; Blampey, H.; Bocci, A.; Bochenek, M.; Bondarenko, V. G.; Bychkov, V.; Callahan, J.; Capeáns Garrido, M.; Cardiel Sas, L.; Catinaccio, A.; Cetin, S. A.; Chandler, T.; Chritin, R.; Cwetanski, P.; Dam, M.; Danielsson, H.; Danilevich, E.; David, E.; Degenhardt, J.; Di Girolamo, B.; Dittus, F.; Dixon, N.; Dobos, D.; Dogan, O. B.; Dolgoshein, B. A.; Dressnandt, N.; Driouchi, C.; Ebenstein, W. L.; Eerola, P.; Egede, U.; Egorov, K.; Evans, H.; Farthouat, P.; Fedin, O. L.; Fowler, A. J.; Fratina, S.; Froidevaux, D.; Fry, A.; Gagnon, P.; Gavrilenko, I. L.; Gay, C.; Ghodbane, N.; Godlewski, J.; Goulette, M.; Gousakov, I.; Grigalashvili, N.; Grishkevich, Y.; Grognuz, J.; Hajduk, Z.; Hance, M.; Hansen, F.; Hansen, J. B.; Hansen, J. D.; Hansen, P. H.; Hare, G. A.; Harvey, A., Jr.; Hauviller, C.; High, A.; Hulsbergen, W.; Huta, W.; Issakov, V.; Istin, S.; Jain, V.; Jarlskog, G.; Jeanty, L.; Kantserov, V. A.; Kaplan, B.; Kapliy, A. S.; Katounine, S.; Kayumov, F.; Keener, P. T.; Kekelidze, G. D.; Khabarova, E.; Khristachev, A.; Kisielewski, B.; Kittelmann, T. H.; Kline, C.; Klinkby, E. B.; Klopov, N. V.; Ko, B. R.; Koffas, T.; Kondratieva, N. V.; Konovalov, S. P.; Koperny, S.; Korsmo, H.; Kovalenko, S.; Kowalski, T. Z.; Krüger, K.; Kramarenko, V.; Kudin, L. G.; LeBihan, A.-C.; LeGeyt, B. C.; Levterov, K.; Lichard, P.; Lindahl, A.; Lisan, V.; Lobastov, S.; Loginov, A.; Loh, C. W.; Lokwitz, S.; Long, M. C.; Lucas, S.; Lucotte, A.; Luehring, F.; Lundberg, B.; Mackeprang, R.; Maleev, V. P.; Manara, A.; Mandl, M.; Martin, A. J.; Martin, F. F.; Mashinistov, R.; Mayers, G. M.; McFarlane, K. W.; Mialkovski, V.; Mills, B. M.; Mindur, B.; Mitsou, V. A.; Mjörnmark, J. U.; Morozov, S. V.; Morris, E.; Mouraviev, S. V.; Muir, A. M.; Munar, A.; Nadtochi, A. V.; Nesterov, S. Y.; Newcomer, F. M.; Nikitin, N.; Novgorodova, O.; Novodvorski, E. G.; Ogren, H.; Oh, S. H.; Oleshko, S. B.; Olivito, D.; Olszowska, J.; Ostrowicz, W.; Passmore, M. S.; Patrichev, S.; Penwell, J.; Perez-Gomez, F.; Peshekhonov, V. D.; Petersen, T. C.; Petti, R.; Placci, A.; Poblaguev, A.; Pons, X.; Price, M. J.; hne, O. Rø; Reece, R. D.; Reilly, M. B.; Rembser, C.; Romaniouk, A.; Rousseau, D.; Rust, D.; Ryabov, Y. F.; Ryjov, V.; Söderberg, M.; Savenkov, A.; Saxon, J.; Scandurra, M.; Schegelsky, V. A.; Scherzer, M. I.; Schmidt, M. P.; Schmitt, C.; Sedykh, E.; Seliverstov, D. M.; Shin, T.; Shmeleva, A.; Sivoklokov, S.; Smirnov, S. Yu; Smirnova, L.; Smirnova, O.; Smith, P.; Sosnovtsev, V. V.; Sprachmann, G.; Subramania, S.; Suchkov, S. I.; Sulin, V. V.; Szczygiel, R. R.; Tartarelli, G.; Thomson, E.; Tikhomirov, V. O.; Tipton, P.; Valls Ferrer, J. A.; Van Berg, R.; Vassilakopoulos, V. I.; Vassilieva, L.; Wagner, P.; Wall, R.; Wang, C.; Whittington, D.; Williams, H. H.; Zhelezko, A.; Zhukov, K.

    2008-10-01

    The ATLAS TRT end-cap is a tracking drift chamber using 245,760 individual tubular drift tubes. It is a part of the TRT tracker which consist of the barrel and two end-caps. The TRT end-caps cover the forward and backward pseudo-rapidity region 1.0 < |η| < 2.0, while the TRT barrel central η region |η| < 1.0. The TRT system provides a combination of continuous tracking with many measurements in individual drift tubes (or straws) and of electron identification based on transition radiation from fibers or foils interleaved between the straws themselves. Along with other two sub-system, namely the Pixel detector and Semi Conductor Tracker (SCT), the TRT constitutes the ATLAS Inner Detector. This paper describes the recently completed and installed TRT end-cap detectors, their design, assembly, integration and the acceptance tests applied during the construction.

  8. Commercial Crew Program CCiCap Partners

    NASA Video Gallery

    NASA's Commercial Crew Program and its newest Commercial Crew Integrated Capability (CCiCap) partners are embracing the American spirit as they advance their integrated rocket and spacecraft design...

  9. DESIGN CONSIDERATION INVOLVING ACTIVE SEDIMENT CAPS

    EPA Science Inventory

    When contaminated sediments pose unacceptable risks to human health and the environment, management activities such as removal, treatment, or isolation of contaminated sediments may be required. Various capping designs are being considered for isolating contaminated sediment are...

  10. DESIGN CONSIDERATION INVOLVING ACTIVE SEDIMENT CAPS (PRESENTATION)

    EPA Science Inventory

    When contaminated sediments pose unacceptable risks to human health and the environment, management activities such as removal, treatment, or isolation of contaminated sediments may be required. Various capping designs are being considered for isolating contaminated sediment are...

  11. Textures in south polar ice cap #1

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Textures of the south polar permanent residual ice cap and polar layered terrains. This 30 x 29 km area image (frame 7709) is centered near 87 degrees south, 77 degrees west.

    Figure caption from Science Magazine

  12. Textures in south polar ice cap #2

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Textures of the south polar permanent residual ice cap and polar layered terrains. This 15 x 14 km area image (frame 7306) is centered near 87 degrees south, 341 degrees west.

    Figure caption from Science Magazine

  13. CCiCap: Sierra Nevada Corporation

    NASA Video Gallery

    NASA announced today its plans to partner with Sierra Nevada Corp. (SNC) for the next phase of the agency's Commercial Crew Program (CCP). Called Commercial Crew integrated Capability (CCiCap), the...

  14. Perfluorocarbon vapor tagging of blasting cap detonators

    DOEpatents

    Dietz, R.N.; Senum, G.I.

    A plug for a blasting cap is made of an elastomer in which is dissolved a perfluorocarbon. The perfluorocarbon is released as a vapor into the ambient over a long period of time to serve as a detectable taggant.

  15. The backward end-cap for the PANDA electromagnetic calorimeter

    NASA Astrophysics Data System (ADS)

    Capozza, L.; Maas, F. E.; Noll, O.; Rodriguez Pineiro, D.; Valente, R.

    2015-02-01

    The PANDA experiment at the new FAIR facility will cover a broad experimental programme in hadron structure and spectroscopy. As a multipurpose detector, the PANDA spectrometer needs to ensure almost 4π coverage of the scattering solid angle, full and accurate multiple-particle event reconstruction and very good particle identification capabilities. The electromagnetic calorimeter (EMC) will be a key item for many of these aspects. Particle energies ranging from some MeVs to several GeVs have to be measured with a relative resolution of 1% ⊕ 2%/√E/GeV . It will be a homogeneous calorimeter made of PbWO4 crystals and will be operated at -25°C, in order to improve the scintillation light yield. With the exception of the very forward section, the light will be detected by large area avalanche photodiodes (APDs). The current pulses from the APDs will be integrated, amplified and shaped by ASIC chips which were developed for this purpose. The whole calorimeter has been designed in three sections: a forward end-cap, a central barrel and a backward end-cap (BWEC). In this contribution, a status report on the development of the BWEC is presented.

  16. Secondary capping beams for offshore drilling platforms

    SciTech Connect

    Albaugh, E. K.

    1985-08-13

    A pair of I-shaped elongated girders secured to, and extending outwardly from, the capping beams of a four pile platform, to form cantilever secondary capping beams which support modified self-contained drilling rigs of a size and weight normally installed on eight pile platforms. Rig modifications comprise separation of pump and engine packages, a pipe rack extension, and a novel skidding system.

  17. Truncated Dual-Cap Nucleation Site Development

    NASA Technical Reports Server (NTRS)

    Matson, Douglas M.; Sander, Paul J.

    2012-01-01

    During heterogeneous nucleation within a metastable mushy-zone, several geometries for nucleation site development must be considered. Traditional spherical dual cap and crevice models are compared to a truncated dual cap to determine the activation energy and critical cluster growth kinetics in ternary Fe-Cr-Ni steel alloys. Results of activation energy results indicate that nucleation is more probable at grain boundaries within the solid than at the solid-liquid interface.

  18. Accurate Measurements of Aircraft Engine Soot Emissions Using a CAPS PMssa Monitor

    NASA Astrophysics Data System (ADS)

    Onasch, Timothy; Thompson, Kevin; Renbaum-Wolff, Lindsay; Smallwood, Greg; Make-Lye, Richard; Freedman, Andrew

    2016-04-01

    We present results of aircraft engine soot emissions measurements during the VARIAnT2 campaign using CAPS PMssa monitors. VARIAnT2, an aircraft engine non-volatile particulate matter (nvPM) emissions field campaign, was focused on understanding the variability in nvPM mass measurements using different measurement techniques and accounting for possible nvPM sampling system losses. The CAPS PMssa monitor accurately measures both the optical extinction and scattering (and thus single scattering albedo and absorption) of an extracted sample using the same sample volume for both measurements with a time resolution of 1 second and sensitivity of better than 1 Mm-1. Absorption is obtained by subtracting the scattering signal from the total extinction. Given that the single scattering albedo of the particulates emitted from the aircraft engine measured at both 630 and 660 nm was on the order of 0.1, any inaccuracy in the scattering measurement has little impact on the accuracy of the ddetermined absorption coefficient. The absorption is converted into nvPM mass using a documented Mass Absorption Coefficient (MAC). Results of soot emission indices (mass soot emitted per mass of fuel consumed) for a turbojet engine as a function of engine power will be presented and compared to results obtained using an EC/OC monitor.

  19. Alpha particles in effective field theory

    SciTech Connect

    Caniu, C.

    2014-11-11

    Using an effective field theory for alpha (α) particles at non-relativistic energies, we calculate the strong scattering amplitude modified by Coulomb corrections for a system of two αs. For the strong interaction, we consider a momentum-dependent interaction which, in contrast to an energy dependent interaction alone [1], could be more useful in extending the theory to systems with more than two α particles. We will present preliminary results of our EFT calculations for systems with two alpha particles.

  20. The effect of polar caps on obliquity

    NASA Technical Reports Server (NTRS)

    Lindner, B. L.

    1993-01-01

    Rubincam has shown that the Martian obliquity is dependent on the seasonal polar caps. In particular, Rubincam analytically derived this dependence and showed that the change in obliquity is directly proportional to the seasonal polar cap mass. Rubincam concludes that seasonal friction does not appear to have changed Mars' climate significantly. Using a computer model for the evolution of the Martian atmosphere, Haberle et al. have made a convincing case for the possibility of huge polar caps, about 10 times the mass of the current polar caps, that exist for a significant fraction of the planet's history. Since Rubincam showed that the effect of seasonal friction on obliquity is directly proportional to polar cap mass, a scenario with a ten-fold increase in polar cap mass over a significant fraction of the planet's history would result in a secular increase in Mars' obliquity of perhaps 10 degrees. Hence, the Rubincam conclusion of an insignificant contribution to Mars' climate by seasonal friction may be incorrect. Furthermore, if seasonal friction is an important consideration in the obliquity of Mars, this would significantly alter the predictions of past obliquity.

  1. alpha-Hexachlorocyclohexane (alpha-HCH)

    Integrated Risk Information System (IRIS)

    alpha - Hexachlorocyclohexane ( alpha - HCH ) ; CASRN 319 - 84 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Ass

  2. Local Structure and Vibrational Properties of alpha-Pu, alpha-U, and the alpha-U Charge Density Wave

    SciTech Connect

    Nelson, E J; Allen, P G; Blobaum, K M; Wall, M A; Booth, C H

    2004-08-10

    The local atomic environment and vibrational properties of atoms in monoclinic pure {alpha}-plutonium as well as orthorhombic pure {alpha}-uranium and its low-temperature charge-density-wave (CDW) modulation are examined by extended x-ray absorption fine structure spectroscopy (EXAFS). Pu L{sub III}-edge and U L{sub III}-edge EXAFS data measured at low temperatures verify the crystal structures of {alpha}-U and {alpha}-Pu samples previously determined by x-ray diffraction and neutron scattering. Debye-Waller factors from temperature-dependent EXAFS measurements are fit with a correlated Debye model. The observed Pu-Pu bond correlated Debye temperature of {theta}{sub cD}({alpha}-Pu) = 162 {+-} 5 K for the pure {alpha}-Pu phase agrees with our previous measurement of the correlated Debye temperature of the gallium-containing {alpha}'-Pu phase in a mixed phase 1.9 at% Ga-doped {alpha}'-Pu/{delta}-Pu alloy. The temperature dependence of the U-U nearest neighbor Debye-Waller factor exhibits a sharp discontinuity in slope near T{sub CDW} = 43 K, the transition temperature at which the charge-density wave (CDW) in {alpha}-U condenses from a soft phonon mode along the (100) direction. Our measurement of the CDW using EXAFS is the first observation of the structure of the CDW in polycrystalline {alpha}-U. The different temperature dependence of the Debye-Waller factor for T < T{sub CDW} can be modeled by the change in bond length distributions resulting from condensation of the charge density wave. For T > T{sub CDW}, the observed correlated Debye temperature of {theta}{sub cD}({alpha}-U) = 199 {+-} 3 K is in good agreement with other measurements of the Debye temperature for polycrystalline {alpha}-U. CDW structural models fit to the {alpha}-U EXAFS data support a squared CDW at the lowest temperatures, with a displacement amplitude of {var_epsilon} = 0.05 {+-} 0.02 {angstrom}.

  3. Alpha-1 Antitrypsin Test

    MedlinePlus

    ... measures the level of the protein AAT in blood. Alpha-1 antitrypsin phenotype testing evaluates the amount and type of AAT being produced and compares it to normal patterns. Alpha-1 antitrypsin genotype testing ( DNA testing) can ...

  4. Alpha-1 antitrypsin test

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003715.htm Alpha-1 antitrypsin test To use the sharing features on this page, please enable JavaScript. Alpha-1 antitrypsin is a laboratory test to measure the ...

  5. A novel self-guided approach to alpha activity training.

    PubMed

    van Boxtel, Geert J M; Denissen, Ad J M; Jäger, Mark; Vernon, David; Dekker, Marian K J; Mihajlović, Vojkan; Sitskoorn, Margriet M

    2012-03-01

    Fifty healthy participants took part in a double-blind placebo-controlled study in which they were either given auditory alpha activity (8-12Hz) training (N=18), random beta training (N=12), or no training at all (N=20). A novel wireless electrode system was used for training without instructions, involving water-based electrodes mounted in an audio headset. Training was applied approximately at central electrodes. Post-training measurement using a conventional full-cap EEG system revealed a 10% increase in alpha activity at posterior sites compared to pre-training levels, when using the conventional index of alpha activity and a non-linear regression fit intended to model individual alpha frequency. This statistically significant increase was present only in the group that received the alpha training, and remained evident at a 3 month follow-up session, especially under eyes open conditions where an additional 10% increase was found. In an exit interview, approximately twice as many participants in the alpha training group (53%) mentioned that the training was relaxing, compared to those in either the beta (20%) or no training (21%) control groups. Behavioural measures of stress and relaxation were indicative of effects of alpha activity training but failed to reach statistical significance. These results are discussed in terms of a lack of statistical power. Overall, results suggest that self-guided alpha activity training using this novel system is feasible and represents a step forward in the ease of instrumental conditioning of brain rhythms.

  6. The Alpha Centauri System.

    ERIC Educational Resources Information Center

    Soderblom, David R.

    1987-01-01

    Describes the Alpha Centauri star system, which is the closest star system to the sun. Discusses the difficulties associated with measurements involving Alpha Centauri, along with some of the recent advances in stellar seismology. Raises questions about the possibilities of planets around Alpha Centauri. (TW)

  7. 75 FR 49527 - Caps Visual Communications, LLC; Black Dot Group; Formerly Known as Caps Group Acquisition, LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-13

    ... Employment and Training Administration Caps Visual Communications, LLC; Black Dot Group; Formerly Known as... Adjustment Assistance on June 24, 2010, applicable to workers of Caps Visual Communications, LLC, Black Dot..., Caps Visual Communications, LLC, Black Dot Group, formerly known as Caps Group Acquisition,...

  8. Binding of protein synthesis initiation factor 4E to oligoribonucleotides: effects of cap accessibility and secondary structure.

    PubMed

    Carberry, S E; Friedland, D E; Rhoads, R E; Goss, D J

    1992-02-11

    The binding of rabbit globin mRNA to the 25-kDa cap binding protein eIF-4E from human erythrocytes was found to be 5.3-fold stronger than the binding of the cap analogue m7GpppG to eIF-4E [Gross et al. (1990) Biochemistry 29, 5008-5012]. In order to investigate whether this effect is due to the longer sequence of nucleotides in globin mRNA or to other features such as cap accessibility or secondary structure, oligoribonucleotide analogues of rabbit alpha-globin mRNA were synthesized by T7 RNA polymerase from a synthetic oligodeoxynucleotide template in the presence of m7GpppG; these oligoribonucleotide analogues possess varying degrees of cap accessibility and secondary structure. Equilibrium association constants for the interaction of these oligoribonucleotides and purified human erythrocyte eIF-4E were obtained from direct fluorescence titration experiments. The data indicate that while the presence of the m7G cap is required for efficient recognition by eIF-4E, the cap need not be completely sterically accessible, since other structural features within the mRNA also influence binding.

  9. Actin capping proteins, CapZ (β-actinin) and tropomodulin in amphioxus striated muscle.

    PubMed

    Bao, Yulong; Kake, Takei; Hanashima, Akira; Nomiya, Yui; Kubokawa, Kaoru; Kimura, Sumiko

    2012-11-15

    CapZ (β-actinin) and tropomodulin (Tmod) are capping proteins involved in the maintenance of thin filaments in vertebrate skeletal muscles. In this study, we focused on amphioxus, the most primitive chordate. We searched for CapZ and Tmod genes in the amphioxus genome and determined their primary structures. Amphioxus possess one CapZα gene (CAPZA) and one CapZβ gene (CAPZB), and the transcripts of these genes were found to be 67%-85% identical to those of human CapZ genes. On the other hand, amphioxus contain one Tmod gene (TMOD), and the product of this gene has an identity of approximately 50% with human Tmod genes 1-4. However, helix 2 of amphioxus Tmod, which is involved in protein-binding to tropomyosin, was highly conserved with approximately 74% identity to human Tmod genes. Western blotting indicated the presence of CapZ and Tmod in the striated muscle of amphioxus. These results suggest that unlike most of vertebrates, such as fish, amphibian, bird, and mammal, CapZ from amphioxus striated muscle is derived from two genes CAPZA and CAPZB, and Tmod is derived from one TMOD gene.

  10. CAP - JET PROPULSION LABORATORY CONTAMINATION ANALYSIS PROGRAM

    NASA Technical Reports Server (NTRS)

    Millard, J. M.

    1994-01-01

    The Jet Propulsion Laboratory Contamination Analysis Program (CAP) is a generalized transient executive analysis computer code which solves realistic mass transport problems in the free molecular flow environment. These transport problems involve mass flux from surface source emission and re-emission, venting, and engine emission. CAP solution capability allows for one-bounce mass reflections if required. CAP was developed to solve thin-film contamination problems in the free molecular flow environment, the intent being to provide a powerful analytic tool for evaluating spacecraft contamination problems. The solution procedure uses an enclosure method based on a lumped-parameter multinodal approach with mass exchange between nodes. Transient solutions are computed by the finite difference Euler method. First-order rate theory is used to represent surface emission and reemission (user care must be taken to insure the problem is appropriate for such behavior), and all surface emission and reflections are assumed diffuse. CAP does not include the effects of post-deposition chemistry or interaction with the ambient atmosphere. CAP reads in a model represented by a multiple-block data stream. CAP allows the user to edit the input data stream and stack sequential editing operations (or cases) in order to make complex changes in behavior (surface temperatures, engine start-up and shut-down, etc.) in a single run if desired. The eight data blocks which make up the input data stream consist of problem control parameters, nodal data (area, temperature, mass, etc.), engine or vent distribution factors (based upon plume definitions), geometric configuration factors (diffuse surface emission), surface capture coefficient tables, source emission rate constant tables, reemission rate constant tables, and partial node to body collapse capability (for deposition rates only). The user must generate this data stream, since neither the problem-specific geometric relationships, the

  11. Transmission Through Carbon Nanotubes with Polyhedral Caps

    NASA Technical Reports Server (NTRS)

    Anantram, M. P.; Govindan, T. R.

    1999-01-01

    We study electron transport between capped carbon nanotubes and a substrate, and relate this transport to the local density of states in the cap. Our results show that that the transmission probability mimics the behavior of the density of states at all energies except those that correspond to localized states. For a capped carbon nanotube that is not connected to a substrate, the localized states do not couple to the coexisting continuum states. However, close proximity of a substrate causes hybridization between these states. As a result, new transmission paths open from substrate states to nanotube continuum states via the localized states in the cap. We show that the interference between various paths gives rise to transmission antiresonances with the minimum equal to zero at the energy of the localized state. The presence of defects in the tube places close to the cap transforms antiresonances into resonances. Depending on the spatial position of defects, these resonant states are capable of carrying a large current. The results of this paper are of relevance to carbon nanotube based studies on molecular electronics and probe tip applications.

  12. Eddy intrustion of hot plasma into the polar cap and formation of polar-cap arcs

    NASA Technical Reports Server (NTRS)

    Chiu, Y. T.; Gorney, D. J.

    1983-01-01

    Under the simple postulate that multiple large scale detachable magnetospheric convection eddies can exist in the vicinity of the convection reversal boundary and in the polar cap, by Kelvin-Helmholtz instability or otherwise, it is shown that a number of seemingly disconnected plasma and electric field observations in the polar cap can be organized into a theory of magnetosheath and plasmasheet plasma intrusion into the polar cap. Current theory of inverted V structures then predicts existence of similar, but weaker, structures at the eddy convection reversal boundaries in the polar cap. A possible consequence is that the polar cap auroras are natural offshoots from discrete oval arcs and evidently are formed by similar processes. The two arc systems can occassionally produce an optical image in the form of the theta aurora.

  13. Embryotoxic effects of benzo(. cap alpha. )pyrene, chrysene, and 7,12-dimethylbenz(. cap alpha. )anthracene in petroleum hydrocarbon mixtures in mallard ducks

    SciTech Connect

    Hoffman, D.J.; Gay, M.L.

    1981-05-01

    In the present study the effects of three polycyclic aromatic hydrocarbons identified in petroleum were examined on mallard (Anas platyrhynchos) embryo development. Addition of benzo(a)pyrene (BaP), chrysene, or 7,12-dimethylbenz(a)anthracene (DMBA) to a synthetic petroleum hydrocarbon mixture of known composition and relatively low embryotoxicity resulted in embryotoxicity that was enhanced or equal to that of crude oil when 10 ..mu../ was applied externally to eggs at 72 h of development. The order of ability to enhance embryotoxicity was DMBA > BaP > chrysene. The temporal pattern of embryonic death was similar to that reported after exposure to crude oil. Retarded growth was accompanied by teratogenicity. Gas chromatographic-mass spectral analysis of externally treated eggs showed the passage of aromatic hydrocarbons including chrysene through the shell and shell membranes to the developing embryos. These findings suggest that the presence of polycyclic aromatic hydrocarbons in petroleum, including BaP, chrysene, and DMBA, significantly enhances the overall embryotoxicity in avian species.

  14. Alpha-induced reaction studies using low-energy RI beams at CRIB

    SciTech Connect

    Yamaguchi, H.; Kahl, D.; Hu, J.; Kubono, S.; Hayakawa, S.; Hashimoto, T.

    2012-11-12

    CRIB (CNS Radioactive Ion Beam separator) is a low-energy RI beam separator at the Center for Nuclear Study (CNS) of the University of Tokyo. Studies on proton and alpha resonance scatterings, ({alpha}, p) reactions, and other types of measurements ({beta}-decay lifetimes etc.) have been performed using RI beams at CRIB, motivated by interests on astrophysical reactions and exotic nuclear structure. Among the studies at CRIB, the measurement of {sup 7}Li+{alpha}/{sup 7}Be+{alpha} resonant scatterings are presented.

  15. Martian north polar cap summer water cycle

    NASA Astrophysics Data System (ADS)

    Brown, Adrian J.; Calvin, Wendy M.; Becerra, Patricio; Byrne, Shane

    2016-10-01

    A key outstanding question in Martian science is "are the polar caps gaining or losing mass and what are the implications for past, current and future climate?" To address this question, we use observations from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) of the north polar cap during late summer for multiple Martian years, to monitor the summertime water cycle in order to place quantitative limits on the amount of water ice deposited and sublimed in late summer. We establish here for the first time the summer cycle of water ice absorption band signatures on the north polar cap. We show that in a key region in the interior of the north polar cap, the absorption band depths grow until Ls = 120, when they begin to shrink, until they are obscured at the end of summer by the north polar hood. This behavior is transferable over the entire north polar cap, where in late summer regions 'flip' from being net sublimating into net condensation mode. This transition or 'mode flip' happens earlier for regions closer to the pole, and later for regions close to the periphery of the cap. The observations and calculations presented herein estimate that on average a water ice layer ∼70 microns thick is deposited during the Ls = 135-164 period. This is far larger than the results of deposition on the south pole during summer, where an average layer 0.6-6 microns deep has been estimated by Brown et al. (2014) Earth Planet. Sci. Lett., 406, 102-109.

  16. Photoactivable caps for reactive metal nanoparticles

    NASA Astrophysics Data System (ADS)

    Patel, Ashish

    The synthesis and stabilization of reactive metal nanoparticles is often challenging under normal atmospheric conditions. This problem can be alleviated by capping and passivation. Our lab has focused on forming polymer coatings on the surface of reactive metal nanoparticles. We discovered a convenient and effective route for stabilization of aluminum nanoparticles (Al NPs), which uses the nascent metal core as a polymerization initiator for various organic monomers. In our previous work, we used this method to passivate the Al NPs using variety of epoxides and copolymers of epoxides and alkenes. These products have demonstrated air stability for weeks to months with little to no degradation in the active Al content. Since our previously synthesized Al NP's were not beneficial for rapid and efficient thermodynamic access to the active Al core, our goal was find polymers that could easily be photochemically activated to enhance such access. Since poly(methyl methacrylate) (PMMA) has photodegrading properties, we used PMMA as a capping agent to passivate Al NPs. In this work, we present capping and stabilization of Al NPs with PMMA, and also with 1,2-epoxyhexane/ PMMA. In our previous work, we increased the stability of Al NP capped with 1,2-epoxy-9-decene by adding 1,13-tetradecadiene as a cross-linker. Here, we used the methyl methacrylate (MMA) monomer as cross-linker for Al NP capped with 1,2-epoxy-9-decene. We have also used the MMA as capping agent. We use powder x-ray diffractametry (PXRD), differential scanning calorimetry (DSC), and thermogravity analysis (TGA) to confirm the presence of elemental Al and ATR-FTIR to confirm the presence of polymers.

  17. Landfill capping: The Croton Point Landfill experience

    SciTech Connect

    Srinivasaraghaven, R.; Gavin, J.M.; Landi, A.M.; Ritchie, M.D.

    1996-12-31

    The Croton Point Landfill Capping involved the installation of an impermeable, geosynthetic cap and the attendant geotechnical cover soils over a 113 acre hazardous waste landfill in Croton-On-Hudson, New York. The remediation process - Remedial Investigation, Feasibility Study (RI/FS) Remedial Design and Remedial Construction lasted six years. This paper sets forth some of the insights and experiences gained during that process and provides some practical recommendations. In particular, the paper evaluates the Croton Landfill experience in regard to Health and Safety; Stormwater Control; erosion and sediment control; QA/QC; leachate treatment and disposal; and wildlife control.

  18. Valve Cap For An Electric Storage Cell

    DOEpatents

    Verhoog, Roelof; Genton, Alain

    2000-04-18

    The valve cap for an electric storage cell includes a central annular valve seat (23) and a membrane (5) fixed by its peripheral edge and urged against the seat by a piston (10) bearing thereagainst by means of a spring (12), the rear end of said spring (12) bearing on the endwall (8) of a chamber (20) formed in the cap and containing the piston (10) and the spring. A vent (19) puts the chamber (20) into communication with the atmosphere. A central orifice (26, 28) through the piston (10) and the membrane (5), enables gas from within the cell to escape via the top vent (19) when the valve opens.

  19. Steel Foil Improves Performance Of Blasting Caps

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Perry, Ronnie; Schimmel, Morry L.

    1990-01-01

    Blasting caps, which commonly include deep-drawn aluminum cups, give significantly higher initiation performance by application of steel foils on output faces. Steel closures 0.005 in. (0.13 mm) thick more effective than aluminum. Caps with directly bonded steel foil produce fragment velocities of 9,300 ft/s (2.8 km/s) with large craters and unpredictable patterns to such degree that no attempts made to initiate explosions. Useful in military and aerospace applications and in specialized industries as mining and exploration for oil.

  20. Pharmacy benefit caps and the chronically ill.

    PubMed

    Joyce, Geoffrey F; Goldman, Dana P; Karaca-Mandic, Pinar; Zheng, Yuhui

    2007-01-01

    In this paper we examine medication use among retirees with employer-sponsored drug coverage both with and without annual benefit limits. We find that pharmacy benefit caps are associated with higher rates of medication discontinuation across the most common therapeutic classes and that only a minority of those who discontinue use reinitiate therapy once coverage resumes. Plan members who reach their cap are more likely than others to switch plans and increase their rate of generic use; however, in most cases, the shift is temporary. Given the similarities between these plans and Part D, we make some inferences about reforms for Medicare.

  1. Supercarrier effective mass isotope effect by interband scattering

    SciTech Connect

    Kristoffel, N.; Oerd, T.

    1999-11-01

    Supercarrier effective mass isotope effect (exponent {beta}) is investigated using a two-band model with interband pair scattering. The corresponding repulsive interaction incorporates besides the dominating electronic (Coulomb) part an electron-phonon contribution inversely proportional to the ionic mass factor. Calculations illustrating the behavior of {Tc}, its isotope exponent {alpha}, and {beta} with doping in La{sub 2{minus}x}Sr{sub x}CuO{sub 4} type underdoped system reflect the observed tendencies. Both {alpha} and {beta} diminish with doping, the sign of {beta} is opposite to {alpha}. A typical estimation gives {vert{underscore}bar}{beta}{vert{underscore}bar} {approximately} 0.2{alpha}.

  2. Approximate formulation of redistribution in the Ly-alpha, Ly-beta, H-alpha system

    NASA Technical Reports Server (NTRS)

    Cooper, J.; Ballagh, R. J.; Hubeny, I.

    1989-01-01

    Simple approximate formulas are given for the coupled redistribution of Ly-alpha, Ly-beta, and H-alpha, by using well-defined approximations to an essentially exact formulation. These formulas incorporate all the essential physics including Raman scattering, lower state radiative decay, and correlated terms representing emission during a collision which must be retained in order that the emission coefficients are properly behaved in the line wings. Approximate expressions for the appropriate line broadening parameters are collected. Finally, practical expressions for the source functions are given. These are formulated through newly introduced nonimpact redistribution functions, which are shown to be reasonably approximated by existing (ordinary and generalized) redistribution functions.

  3. Electron microscope characteristics of dentin repair after hydroxylapatite direct pulp capping in rats.

    PubMed

    Jaber, L; Mascrès, C; Donohue, W B

    1991-11-01

    In order to study the osteogenic action of hydroxylapatite (HA) on the dental pulp, a pulp capping experiment was designed using the rat upper molar. Under general anesthesia, molar teeth in 14 male Sprague-Dawley rats were pulp capped with Osteogen (HA) or with Dycal as a control material. After pulp capping, the maxillary molars cavities were restored with amalgam and a pedodontic steel crown was adjusted and sealed over the molar teeth on either side of the maxilla. After 7 days, the areas of necrosis and acute inflammation were more evident in the pulps treated with Dycal than with Osteogen. Hard tissue formation began to appear around dentinal chips in the pulp and extended from the cavity walls into the pulp regardless of the material that was used. Furthermore, this calcified material was scattered throughout the pulp when Osteogen was used, but was not observed in the Dycal treated pulps. The hard tissue formation was thought to be due to the putative fibroblasts and odontoblasts found in the pulp. After 28 days dense dentinal tissue was observed bridging the exposure site when Dycal was used. The dentinal tissues formed with Osteogen was always of a globular type, and showed an irregular distribution. Since Osteogen tends to cause areas of dystrophic calcification in the pulp, its use is not be recommended for pulp capping purposes in humans, because these areas of calcification would make future endodontic treatment difficult. PMID:1661333

  4. Alkylamine capped metal nanoparticle "inks" for printable SERS substrates, electronics and broadband photodetectors.

    PubMed

    Polavarapu, Lakshminarayana; Manga, Kiran Kumar; Yu, Kuai; Ang, Priscilla Kailian; Cao, Hanh Duyen; Balapanuru, Janardhan; Loh, Kian Ping; Xu, Qing-Hua

    2011-05-01

    We report a facile and general method for the preparation of alkylamine capped metal (Au and Ag) nanoparticle "ink" with high solubility. Using these metal nanoparticle "inks", we have demonstrated their applications for large scale fabrication of highly efficient surface enhanced Raman scattering (SERS) substrates by a facile solution processing method. These SERS substrates can detect analytes down to a few nM. The flexible plastic SERS substrates have also been demonstrated. The annealing temperature dependent conductivity of the nanoparticle films indicated a transition temperature above which high conductivity was achieved. The transition temperature could be tailored to the plastic compatible temperatures by using proper alkylamine as the capping agent. The ultrafast electron relaxation studies of the nanoparticle films demonstrated that faster electron relaxation was observed at higher annealing temperatures due to stronger electronic coupling between the nanoparticles. The applications of these highly concentrated alkylamine capped metal nanoparticle inks for the printable electronics were demonstrated by printing the oleylamine capped gold nanoparticles ink as source and drain for the graphene field effect transistor. Furthermore, the broadband photoresponse properties of the Au and Ag nanoparticle films have been demonstrated by using visible and near-infrared lasers. These investigations demonstrate that these nanoparticle "inks" are promising for applications in printable SERS substrates, electronics, and broadband photoresponse devices.

  5. Survey of Enabling Technologies for CAPS

    NASA Technical Reports Server (NTRS)

    Antol, Jeffrey; Mazanek, Daniel D.; Koons, Robert H.

    2005-01-01

    The enabling technologies required for the development of a viable Comet/Asteroid Protection System (CAPS) can be divided into two principal areas: detection and deflection/orbit modification. With the proper funding levels, many of the technologies needed to support a CAPS architecture could be achievable within the next 15 to 20 years. In fact, many advanced detection technologies are currently in development for future in-space telescope systems such as the James Webb Space Telescope (JWST), formerly known as the Next Generation Space Telescope. It is anticipated that many of the JWST technologies would be available for application for CAPS detection concepts. Deflection/orbit modification technologies are also currently being studied as part of advanced power and propulsion research. However, many of these technologies, such as extremely high-output power systems, advanced propulsion, heat rejection, and directed energy systems, would likely be farther term in availability than many of the detection technologies. Discussed subsequently is a preliminary examination of the main technologies that have been identified as being essential to providing the element functionality defined during the CAPS conceptual study. The detailed requirements for many of the technology areas are still unknown, and many additional technologies will be identified as future in-depth studies are conducted in this area.

  6. Plasma structuring in the polar cap

    SciTech Connect

    Basu, S.; Basu, S.; Weber, E.J.; Bishop, G.J.

    1990-01-01

    Propagation experiments providing scintillation, total electron content and drift data in the field of view of an all-sky imager near the magnetic polar in Greenland are utilized to investigate the manner in which ionospheric plasma becomes structured within the polar cap. It is found that under IMF Bz southward conditions, large scale ionization patches which are convected through the dayside cusp into the polar cap get continually structured. The structuring occurs through the ExB gradient drift instability process which operates through an interaction between the antisunward plasma convection in the neutral rest frame and large scale plasma density gradients that exist at the edges of the ionization patches. It is shown that with the increase of solar activity the strength of the irregularities integrated through the ionosphere is greatly increased. Under the IMF Bz northward conditions, the plasma structuring occurs around the polar cap arcs in the presence of inhomogeneous electric field or disordered plasma convection. In that case, the irregularity generation is caused by the competing processes of non-linear Kelvin-Helmholtz instability driven by sheared plasma flows and the gradient drift instability process which operates in the presence of dawn-dusk motion of arc structures. The integrated strength of this class of irregularities also exhibits marked increase with increasing solar activity presumably because the ambient plasma density over the polar cap is enhanced.

  7. 47 CFR 54.675 - Cap.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 3 2013-10-01 2013-10-01 false Cap. 54.675 Section 54.675 Telecommunication..., the Administrator shall implement a filing window period that treats all eligible health care providers filing within the window period as if their applications were simultaneously received. (3) (4)...

  8. Capping blowouts from Iran's 8-year war

    SciTech Connect

    Sayers, B. )

    1991-07-01

    Control well blown up by the Iraqi military were a 2 1/2 year legacy left the National Iranian Oil Co. at the end of this long conflict. This final installment of a 2-part series describes capping of the largest wind oil well.

  9. 21 CFR 884.5250 - Cervical cap.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cervical cap. 884.5250 Section 884.5250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES... collect menstrual flow or to aid artificial insemination. This generic type of device is not...

  10. Natural attenuation processes during in situ capping.

    PubMed

    Himmelheber, David W; Pennell, Kurt D; Hughes, Joseph B

    2007-08-01

    Chlorinated solvents are common groundwater contaminants that threaten surface water quality and benthic health when present in groundwater seeps. Aquatic sediments can act as natural biobarriers to detoxify chlorinated solvent plumes via reductive dechlorination. In situ sediment capping, a remedial technique in which clean material is placed at the sediment-water interface, may alter sedimentary natural attenuation processes. This research explores the potential of Anacostia River sediment to naturally attenuate chlorinated solvents under simulated capping conditions. Results of microcosm studies demonstrated that intrinsic dechlorination of dissolved-phase PCE to ethene was possible, with electron donor availability controlling microbial activity. A diverse microbial community was present in the sediment, including multiple Dehalococcoides strains indicated by the amplification of the reductive dehalogenases tceA, vcrA, and bvcA. An upflow column simulating a capped sediment bed subject to PCE-contaminated groundwater seepage lost dechlorination activity with time and only achieved complete dechlorination when microorganisms present in the sediment were provided electron donor. Increases in effluent chloroethene concentrations during the period of biostimulation were attributed to biologically enhanced desorption and the formation of less sorptive dechlorination products. These findings suggest that in situ caps should be designed to account for reductions in natural biobarrier reactivity and for the potential breakthrough of groundwater contaminants. PMID:17822095

  11. Shrinking ice caps in the spotlight.

    PubMed

    Gross, Michael

    2014-10-01

    From the disappearing sea ice of the Arctic to the thriving microbial communities in subglacial lakes of Antarctica, the Earth's ice caps have often made the news in recent months and years, and polar science has emerged as being crucial to our understanding of our planet's biology and climate. Michael Gross reports.

  12. 47 CFR 54.507 - Cap.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... yearly average GDP-CPI is determined, the Wireline Competition Bureau shall publish a public notice in... category one services, the Administrator, at the direction of the Wireline Competition Bureau, shall direct... notwithstanding the annual cap. The Chief, Wireline Competition Bureau, is delegated authority to determine...

  13. Science CAP: Curriculum Assistance Program. [Multimedia.

    ERIC Educational Resources Information Center

    DEMCO, Inc., Madison, WI.

    Science Curriculum Assistance Program (Science CAP(TM)) is a multimedia package developed to create a model for preserving classroom science activities that can be shared and customized by teachers. This program is designed to assist teachers in preparing classroom science activities for grades five through eight, and to foster an environment of…

  14. Natural attenuation processes during in situ capping.

    PubMed

    Himmelheber, David W; Pennell, Kurt D; Hughes, Joseph B

    2007-08-01

    Chlorinated solvents are common groundwater contaminants that threaten surface water quality and benthic health when present in groundwater seeps. Aquatic sediments can act as natural biobarriers to detoxify chlorinated solvent plumes via reductive dechlorination. In situ sediment capping, a remedial technique in which clean material is placed at the sediment-water interface, may alter sedimentary natural attenuation processes. This research explores the potential of Anacostia River sediment to naturally attenuate chlorinated solvents under simulated capping conditions. Results of microcosm studies demonstrated that intrinsic dechlorination of dissolved-phase PCE to ethene was possible, with electron donor availability controlling microbial activity. A diverse microbial community was present in the sediment, including multiple Dehalococcoides strains indicated by the amplification of the reductive dehalogenases tceA, vcrA, and bvcA. An upflow column simulating a capped sediment bed subject to PCE-contaminated groundwater seepage lost dechlorination activity with time and only achieved complete dechlorination when microorganisms present in the sediment were provided electron donor. Increases in effluent chloroethene concentrations during the period of biostimulation were attributed to biologically enhanced desorption and the formation of less sorptive dechlorination products. These findings suggest that in situ caps should be designed to account for reductions in natural biobarrier reactivity and for the potential breakthrough of groundwater contaminants.

  15. Nuclear waste vitrification efficiency: cold cap reactions

    SciTech Connect

    Hrma, Pavel R.; Kruger, Albert A.; Pokorny, Richard

    2012-12-15

    The cost and schedule of nuclear waste treatment and immobilization are greatly affected by the rate of glass production. Various factors influence the performance of a waste-glass melter. One of the most significant, and also one of the least understood, is the process of batch melting. Studies are being conducted to gain fundamental understanding of the batch reactions, particularly those that influence the rate of melting, and models are being developed to link batch makeup and melter operation to the melting rate. Batch melting takes place within the cold cap, i.e., a batch layer floating on the surface of molten glass. The conversion of batch to glass consists of various chemical reactions, phase transitions, and diffusion-controlled processes. These include water evaporation (slurry feed contains as high as 60% water), gas evolution, the melting of salts, the formation of borate melt, reactions of borate melt with molten salts and with amorphous oxides (Fe2O3 and Al2O3), the formation of intermediate crystalline phases, the formation of a continuous glass-forming melt, the growth and collapse of primary foam, and the dissolution of residual solids. To this list we also need to add the formation of secondary foam that originates from molten glass but accumulates on the bottom of the cold cap. This study presents relevant data obtained for a high-level-waste melter feed and introduces a one-dimensional (1D) mathematical model of the cold cap as a step toward an advanced three-dimensional (3D) version for a complete model of the waste glass melter. The 1D model describes the batch-to-glass conversion within the cold cap as it progresses in a vertical direction. With constitutive equations and key parameters based on measured data, and simplified boundary conditions on the cold-cap interfaces with the glass melt and the plenum space of the melter, the model provides sensitivity analysis of the response of the cold cap to the batch makeup and melter conditions

  16. NUCLEAR WASTE VITRIFICATION EFFICIENCY COLD CAP REACTIONS

    SciTech Connect

    KRUGER AA; HRMA PR; POKORNY R

    2011-07-29

    The cost and schedule of nuclear waste treatment and immobilization are greatly affected by the rate of glass production. Various factors influence the performance of a waste-glass melter. One of the most significant, and also one of the least understood, is the process of batch melting. Studies are being conducted to gain fundamental understanding of the batch reactions, particularly those that influence the rate of melting, and models are being developed to link batch makeup and melter operation to the melting rate. Batch melting takes place within the cold cap, i.e., a batch layer floating on the surface of molten glass. The conversion of batch to glass consists of various chemical reactions, phase transitions, and diffusion-controlled processes. These include water evaporation (slurry feed contains as high as 60% water), gas evolution, the melting of salts, the formation of borate melt, reactions of borate melt with molten salts and with amorphous oxides (Fe{sub 2}O{sub 3} and Al{sub 2}O{sub 3}), the formation of intermediate crystalline phases, the formation of a continuous glass-forming melt, the growth and collapse of primary foam, and the dissolution of residual solids. To this list we also need to add the formation of secondary foam that originates from molten glass but accumulates on the bottom of the cold cap. This study presents relevant data obtained for a high-level-waste melter feed and introduces a one-dimensional (1D) mathematical model of the cold cap as a step toward an advanced three-dimensional (3D) version for a complete model of the waste glass melter. The 1D model describes the batch-to-glass conversion within the cold cap as it progresses in a vertical direction. With constitutive equations and key parameters based on measured data, and simplified boundary conditions on the cold-cap interfaces with the glass melt and the plenum space of the melter, the model provides sensitivity analysis of the response of the cold cap to the batch makeup

  17. Studies of alpha-induced astrophysical reactions at CRIB

    NASA Astrophysics Data System (ADS)

    Yamaguchi, H.; Hashimoto, T.; Hayakawa, S.; Binh, D. N.; Kahl, D.; Kubono, S.

    2010-08-01

    CRIB (CNS Radioactive Ion Beam separator ) is a low-energy RI beam separator at the Center for Nuclear Study (CNS) of the University of Tokyo. Using the RI beams at CRIB, many measurements on proton alpha resonance scatterings, (α,p) reactions, and others were performed in recent years mainly for studying astrophysical reactions and exotic nuclear structure. Among them, the results on the 7Li+α resonance scatterings are presented.

  18. Sublimation Model for Formation of Martian Residual Cap Depressions

    NASA Astrophysics Data System (ADS)

    Byrne, S.; Ingersoll, A. P.

    2000-10-01

    In an effort for explain the formation of the 'Swiss-cheese' terrain visible on the southern residual cap of Mars, we have developed a radiative model to follow the growth/decay of an initial depression due to sublimation/condensation of carbon dioxide. The pits making up this terrain have many distinctive features, they are shallow ( 10m deep), with steep walls and flat floors and contain an interior moat which runs along the bottom of the walls. They have lateral sizes ranging from a few 10's of meters to a kilometer and are quasi-circular. The model accounts for incident sunlight, emitted thermal radiation, and scattered short and long wave radiation. We have investigated many cases involving pure dry-ice with constant albedo, albedo as a function of insolation, and differing albedo for fresh and residual frost (the latter has lower albedo). The last case mentioned shows the most promising results to date. With these conditions it is possible for the depressions to grow and develop flat central portions although they still lack the observed steep walls of the pits. In the other cases mentioned the initial depressions heal themselves and disappear into the surrounding terrain. Other processes or materials could be responsible for the remainder of the observed features. Water ice stored a few meters under a carbon dioxide covering would have dramatic effects on the growth of any depression which encounters it, both due to its low sublimation rate and its ability to store heat. We will extend the current model to include a water ice layer and account for the subsequent heat storage which could possibly follow. For water ice models, a challenge is to reproduce the low brightness temperatures that persist throughout the summer at the residual south polar cap.

  19. High-pressure jet cutters improve capping operations

    SciTech Connect

    Abel, L.W.; Campbell, P.J.; Bowden, J.R. Sr.

    1995-05-08

    Advances in abrasive cutting technology have improved the methods for removing damaged equipment and preparing wellheads for capping. This technology, much of which was refined during well control operations in Kuwait in 1991, can improve the safety and efficiency of capping jobs by cutting wellheads or casing quickly and cleanly. The majority of well control jobs involve one of three types of capping operations: capping to a flange, capping by installing a wellhead, or capping to a casing stub. Capping operations are often the first major step in regaining control of the well during blowout intervention. Proper planning of a capping operation must take into account the mass flow rate, combustible nature of the flow, well bore geometry, and operations in the post-capping phase of the project. The paper discusses capping vehicles, tree removal, jet cutters, capping to a flange, capping to a stub, swallowing the stub, spin-on technique, capping on fire, stinging, offshore blowouts, firefighting, pollution control, intervention equipment, and rig removal.

  20. Pauli-blocking effects in neutron-alpha reactions

    SciTech Connect

    Avrigeanu, M. |; Avrigeanu, V.; Antonov, A.N.; Chadwick, M.B.; Hodgson, P.E.; Stoitsov, M.V.

    1994-06-01

    We present a knockout model for direct (n,{alpha}) reactions in which the residual nucleus is left in a continuum excited state. The interaction of the neutron with a preformed alpha particle inside the nucleus is related to the free neutron-alpha scattering cross-section, with modifications to account for nuclear medium effects, including Fermi motion, Pauli-blocking, and barrier penetration. Phase space restrictions for the four nucleons of the alpha-particle after the knockout are imposed by a Pauli-blocking function. We apply this model, along with evaporation contributions, to analyze excitation functions of (n,{alpha} reactions on {sup 48}Ti, {sup 51}V, {sup 52}Cr, {sup 54}Fe, {sup 55}Mn, and {sup 59}Co. Good agreement is obtained between our calculations and experimental measurements. Values for the local Fermi energy in the region from where knockout occurs indicate a surface reaction.

  1. Entropy-Alpha Classification Alternative for Polarimetric SAR Image

    NASA Astrophysics Data System (ADS)

    Praks, J.; Hallikainen, M.

    2003-04-01

    In this work we discuss SAR target entropy and alpha angle relations to other scattering covariance matrix characteristics and similarity invariants. It is shown that the sum of squared elements of the coherency matrix, normalized by its trace and determinant, has many common features with target entropy parameter. The first element of the matrix is very similar to alpha angle parameter describing scattering mechanism. Possibilities to use the sum of squared elements, determinant and first element of normalized coherency matrix for classification are studied. It appears that classification schemes very similar to entropy-alpha can be established. However, classification results differ slightly from those of entropy-alpha classification as here discussed two-parameter classifications depend on three variables, although parameters are in all cases the same. As an example, NASA/JPL AIRSAR L-Band image of the San Francisco Bay was classified with both proposed schemes and original entropy-alpha classification. The size of the used image was 224 x 256 pixels. The new algorithms classified 97% and 96%, respectively, of pixels to the same classes as entropy-alpha classification. The discussed similarity invariants are straightforward to calculate and they have been used to describe covariance matrix properties in statistics. Virtually are proposed classification algorithms equivalent with entropy-alpha classification because all three use the same amount of information from covariance matrix. However, proposed parameter pairs are much easier to calculate, as they do not require the computation of eigenvalues and eigenvectors.

  2. Structure, stability and folding of the alpha-helix.

    PubMed

    Doig, A J; Andrew, C D; Cochran, D A; Hughes, E; Penel, S; Sun, J K; Stapley, B J; Clarke, D T; Jones, G R

    2001-01-01

    Pauling first described the alpha-helix nearly 50 years ago, yet new features of its structure continue to be discovered, using peptide model systems, site-directed mutagenesis, advances in theory, the expansion of the Protein Data Bank and new experimental techniques. Helical peptides in solution form a vast number of structures, including fully helical, fully coiled and partly helical. To interpret peptide results quantitatively it is essential to use a helix/coil model that includes the stabilities of all these conformations. Our models now include terms for helix interiors, capping, side-chain interactions, N-termini and 3(10)-helices. The first three amino acids in a helix (N1, N2 and N3) and the preceding N-cap are unique, as their amide NH groups do not participate in backbone hydrogen bonding. We surveyed their structures in proteins and measured their amino acid preferences. The results are predominantly rationalized by hydrogen bonding to the free NH groups. Stabilizing side-chain-side-chain energies, including hydrophobic interactions, hydrogen bonding and polar/non-polar interactions, were measured accurately in helical peptides. Helices in proteins show a preference for having approximately an integral number of turns so that their N- and C-caps lie on the same side. There are also strong periodic trends in the likelihood of terminating a helix with a Schellman or alpha L C-cap motif. The kinetics of alpha-helix folding have been studied with stopped-flow deep ultraviolet circular dichroism using synchrotron radiation as the light source; this gives a far superior signal-to-noise ratio than a conventional instrument. We find that poly(Glu), poly(Lys) and alanine-based peptides fold in milliseconds, with longer peptides showing a transient overshoot in helix content.

  3. Low flammability cap-sensitive flexible explosive composition

    DOEpatents

    Wagner, Martin G.

    1992-01-14

    A cap-sensitive flexible explosive composition of reduced flammability is provided by incorporating a finely divided, cap-sensitive explosive in a flame resistant polymeric binder system which contains a compatible flame retardant material.

  4. Development of an unbonded capping system for clay masonry prisms

    SciTech Connect

    Crouch, L.K.; Henderson, R.C.; Sneed, W.A. Jr.

    1999-07-01

    To ascertain if an unbonded capping system was feasible for clay masonry prisms, the compressive strengths of thirty clay masonry prisms capped with an unbonded capping system modeled after ASTM C 1231 were compared with those of thirty masonry prisms capped with ASTM C 67 approved high-strength gypsum cement at the ages of 7 and 28 days. All prisms were constructed by a professional mason using Grade SW, Type FBS cored face brick from the same lot and ASTM C 270 Type S PC-lime mortar. There was no significant difference in mean compressive strength for the two capping methods at either age. In addition, capping with the unbonded capping system was faster and easier. Further, 28-day results obtained using the unbonded capping system had a lower coefficient of variation and higher mean compressive strength than those obtained with high-strength gypsum.

  5. Crystalline Gibbs monolayers of DNA-capped nanoparticles at the air-liquid interface.

    PubMed

    Campolongo, Michael J; Tan, Shawn J; Smilgies, Detlef-M; Zhao, Mervin; Chen, Yi; Xhangolli, Iva; Cheng, Wenlong; Luo, Dan

    2011-10-25

    Using grazing-incidence small-angle X-ray scattering in a special configuration (parallel SAXS, or parSAXS), we mapped the crystallization of DNA-capped nanoparticles across a sessile droplet, revealing the formation of crystalline Gibbs monolayers of DNA-capped nanoparticles at the air-liquid interface. We showed that the spatial crystallization can be regulated by adjusting both ionic strength and DNA sequence length and that a modified form of the Daoud-Cotton model could describe and predict the resulting changes in interparticle spacing. Gibbs monolayers at the air-liquid interface provide an ideal platform for the formation and study of equilibrium nanostructures and may afford exciting routes toward the design of programmable 2D plasmonic materials and metamaterials.

  6. Rocket measurements within a polar cap arc - Plasma, particle, and electric circuit parameters

    NASA Technical Reports Server (NTRS)

    Weber, E. J.; Ballenthin, J. O.; Basu, S.; Carlson, H. C.; Hardy, D. A.; Maynard, N. C.; Kelley, M. C.; Fleischman, J. R.; Pfaff, R. F.

    1989-01-01

    Results are presented from the Polar Ionospheric Irregularities Experiment (PIIE), conducted from Sondrestrom, Greenland, on March 15, 1985, designed for an investigation of processes which lead to the generation of small-scale (less than 1 km) ionospheric irregularities within polar-cap F-layer auroras. An instrumented rocket was launched into a polar cap F layer aurora to measure energetic electron flux, plasma, and electric circuit parameters of a sun-aligned arc, coordinated with simultaneous measurements from the Sondrestrom incoherent scatter radar and the AFGL Airborne Ionospheric Observatory. Results indicated the existence of two different generation mechanisms on the dawnside and duskside of the arc. On the duskside, parameters are suggestive of an interchange process, while on the dawnside, fluctuation parameters are consistent with a velocity shear instability.

  7. Determination of Alpha

    NASA Astrophysics Data System (ADS)

    Chmeissani, Mokhtar Abdallah

    The determination of the strong coupling constant alpha_ s, using Energy-Energy Correlation Asymmetry and jet mass difference with Mark II data at SLC (91 GeV) is presented. In Energy-Energy Correlation Asymmetry (EECA), we used the same systematic procedure used to determine alpha_ s with MARK II data at PEP (29 GeV). The chi^2 fit suggests that alpha_ s = 0.119 +/- 0.007(stat.) +/- 0.007(syst.). In addition, we used the EECA method to determine the QCD scale parameter Lambda_{LLA}. The chi^2 fit suggests that Lambda _{LLA} = 420 +/- 90(stat.) MeV. In the jet mass difference method, the determination of alpha_ s is based on QCD calculations up to 2nd order. We showed that in this method we are able to reproduce the value of alpha _ s from a Monte Carlo sample to a very high accuracy. The result with this method is alpha _ s = 0.134 +/- 0.085(stat.) +/- 0.004(syst.). The two values of alpha_ s presented in this work are in agreement within the error bars and in a good agreement with recent results of alpha_ s published from other e^+e^- experiments.

  8. Convergence of the nucleus-nucleus Glauber multiple scattering series

    SciTech Connect

    Usmani, A.A.; Ahmad, I. )

    1991-05-01

    The Glauber {ital S}-matrix operator for nucleus-nucleus scattering is expressed as a finite series of matrix elements involving Bell's polynomials. Analyzing {alpha}{sup 4}He elastic-scattering data at the incident momentum of 4.32 GeV/{ital c}, we infer that our expansion is appreciably converging. Further, by applying closure over target and projectile states and neglecting a certain class of terms involving intermediate excitations, we arrive at a recurrence relation for nucleus-nucleus multiple scattering series terms, which invites further study as it seems to provide a simple method for calculating the nucleus-nucleus elastic-scattering cross section.

  9. Beta scattering and beta back-scattering from a thin target

    SciTech Connect

    Bafandeh, H.R.

    1992-01-01

    An experimental and theoretical technique is presented to determine the distribution of transmitted and back scattered beta particles as a function of angle of incident radiation on a target. Scatterers used consisted of metallic foils of various thicknesses and atomic number, such as Al, Zn, Fe, Ag, and Zr. Three pure beta-emitting radionuclides, [sup 32]P, [sup 204]Tl, and [sup 147]Pm characterized by end-point energies of 1.71 Mev, 0.769 Mev, and 0.225 Mev, respectively, were prepared as individual sources and used in the experimental work. A scintillation detector used in conjunction with the target scatterer and a specially designed fixture that allowed rotation about its vertical rotation axis provided the proper geometry and shielding for this experiment. Finally, the author attempted to compare experimental results with computer calculations and derived an algebraic equation to predict the intensity of beta particle back-scattered radiation as a function of energy of the source material, the scattering angle, scatterer thickness, and the material of the target scatterer. Unlike the case of heavy charged particles such as alpha particles, the effects of beta particle back scattering on dose calculations cannot be ignored. Scattering effects also have important implications with respect to the measurement of beta-emitting radionuclides and the measurements of beta radiation dose.

  10. Improved color coordinates of green monochromatic pc-LED capped with a band-pass filter.

    PubMed

    Oh, Ji Hye; Yang, Su Ji; Sung, Yeon-Goog; Do, Young Rag

    2013-02-25

    This study introduces a "greener" green monochromatic phosphor-converted light-emitting diode (pc-LED) using a band-pass filter (BPF) combined with a long-pass dichroic filter (LPDF) and a short-pass dichroic filter (SPDF) to improve the color quality of our previously developed LPDF-capped green pc-LED. This can also address the drawbacks of III-V semiconductor-type green LEDs, which show a low luminous efficacy and a poor current dependence of the efficacy and color coordinates compared to blue semiconductor-type LEDs. The optical properties of green monochromatic pc-LEDs using a BPF are compared with those of LPDF-capped green pc-LEDs, which have a broad band spectrum, and III-V semiconductor-type green LEDs by changing the transmittance wavelength range of the BPF and the peak wavelength of the green phosphors. BPF-capped green monochromatic pc-LEDs provide a high luminous efficacy (134 lm/W at 60 mA), and "greener" 1931 Commission Internationale d'Eclairage (CIE; CIEx, CIEy) color coordinates (0.24, 0.66) owing to the narrowed emission spectrum. We also propose a two-dimensional (2D) polystyrene (PS) microbead (2-μm diameter) monolayer as a scattering layer to overcome the poor angular dependence of the color coordinates of the transmitted light through a nano-multilayered dichroic filter such as an LPDF or BPF. The 2D PS scattering layer improves the angular dependence of the green color emitted from a BPF-capped green pc-LED with only 3% loss of luminous efficacy.

  11. Event counting alpha detector

    DOEpatents

    Bolton, R.D.; MacArthur, D.W.

    1996-08-27

    An electrostatic detector is disclosed for atmospheric radon or other weak sources of alpha radiation. In one embodiment, nested enclosures are insulated from one another, open at the top, and have a high voltage pin inside and insulated from the inside enclosure. An electric field is produced between the pin and the inside enclosure. Air ions produced by collision with alpha particles inside the decay volume defined by the inside enclosure are attracted to the pin and the inner enclosure. With low alpha concentrations, individual alpha events can be measured to indicate the presence of radon or other alpha radiation. In another embodiment, an electrical field is produced between parallel plates which are insulated from a single decay cavity enclosure. 6 figs.

  12. Event counting alpha detector

    DOEpatents

    Bolton, Richard D.; MacArthur, Duncan W.

    1996-01-01

    An electrostatic detector for atmospheric radon or other weak sources of alpha radiation. In one embodiment, nested enclosures are insulated from one another, open at the top, and have a high voltage pin inside and insulated from the inside enclosure. An electric field is produced between the pin and the inside enclosure. Air ions produced by collision with alpha particles inside the decay volume defined by the inside enclosure are attracted to the pin and the inner enclosure. With low alpha concentrations, individual alpha events can be measured to indicate the presence of radon or other alpha radiation. In another embodiment, an electrical field is produced between parallel plates which are insulated from a single decay cavity enclosure.

  13. Imaging alpha particle detector

    DOEpatents

    Anderson, D.F.

    1980-10-29

    A method and apparatus for detecting and imaging alpha particles sources is described. A dielectric coated high voltage electrode and a tungsten wire grid constitute a diode configuration discharge generator for electrons dislodged from atoms or molecules located in between these electrodes when struck by alpha particles from a source to be quantitatively or qualitatively analyzed. A thin polyester film window allows the alpha particles to pass into the gas enclosure and the combination of the glass electrode, grid and window is light transparent such that the details of the source which is imaged with high resolution and sensitivity by the sparks produced can be observed visually as well. The source can be viewed directly, electronically counted or integrated over time using photographic methods. A significant increase in sensitivity over other alpha particle detectors is observed, and the device has very low sensitivity to gamma or beta emissions which might otherwise appear as noise on the alpha particle signal.

  14. Imaging alpha particle detector

    DOEpatents

    Anderson, David F.

    1985-01-01

    A method and apparatus for detecting and imaging alpha particles sources is described. A conducting coated high voltage electrode (1) and a tungsten wire grid (2) constitute a diode configuration discharge generator for electrons dislodged from atoms or molecules located in between these electrodes when struck by alpha particles from a source (3) to be quantitatively or qualitatively analyzed. A thin polyester film window (4) allows the alpha particles to pass into the gas enclosure and the combination of the glass electrode, grid and window is light transparent such that the details of the source which is imaged with high resolution and sensitivity by the sparks produced can be observed visually as well. The source can be viewed directly, electronically counted or integrated over time using photographic methods. A significant increase in sensitivity over other alpha particle detectors is observed, and the device has very low sensitivity to gamma or beta emissions which might otherwise appear as noise on the alpha particle signal.

  15. 31 CFR 50.90 - Cap on annual liability.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Cap on annual liability. 50.90 Section 50.90 Money and Finance: Treasury Office of the Secretary of the Treasury TERRORISM RISK INSURANCE PROGRAM Cap on Annual Liability § 50.90 Cap on annual liability. Pursuant to Section 103 of the Act,...

  16. mRNA capping: biological functions and applications.

    PubMed

    Ramanathan, Anand; Robb, G Brett; Chan, Siu-Hong

    2016-09-19

    The 5' m7G cap is an evolutionarily conserved modification of eukaryotic mRNA. Decades of research have established that the m7G cap serves as a unique molecular module that recruits cellular proteins and mediates cap-related biological functions such as pre-mRNA processing, nuclear export and cap-dependent protein synthesis. Only recently has the role of the cap 2'O methylation as an identifier of self RNA in the innate immune system against foreign RNA has become clear. The discovery of the cytoplasmic capping machinery suggests a novel level of control network. These new findings underscore the importance of a proper cap structure in the synthesis of functional messenger RNA. In this review, we will summarize the current knowledge of the biological roles of mRNA caps in eukaryotic cells. We will also discuss different means that viruses and their host cells use to cap their RNA and the application of these capping machineries to synthesize functional mRNA. Novel applications of RNA capping enzymes in the discovery of new RNA species and sequencing the microbiome transcriptome will also be discussed. We will end with a summary of novel findings in RNA capping and the questions these findings pose. PMID:27317694

  17. 31 CFR 50.90 - Cap on annual liability.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false Cap on annual liability. 50.90 Section 50.90 Money and Finance: Treasury Office of the Secretary of the Treasury TERRORISM RISK INSURANCE PROGRAM Cap on Annual Liability § 50.90 Cap on annual liability. Pursuant to Section 103 of the Act,...

  18. mRNA capping: biological functions and applications.

    PubMed

    Ramanathan, Anand; Robb, G Brett; Chan, Siu-Hong

    2016-09-19

    The 5' m7G cap is an evolutionarily conserved modification of eukaryotic mRNA. Decades of research have established that the m7G cap serves as a unique molecular module that recruits cellular proteins and mediates cap-related biological functions such as pre-mRNA processing, nuclear export and cap-dependent protein synthesis. Only recently has the role of the cap 2'O methylation as an identifier of self RNA in the innate immune system against foreign RNA has become clear. The discovery of the cytoplasmic capping machinery suggests a novel level of control network. These new findings underscore the importance of a proper cap structure in the synthesis of functional messenger RNA. In this review, we will summarize the current knowledge of the biological roles of mRNA caps in eukaryotic cells. We will also discuss different means that viruses and their host cells use to cap their RNA and the application of these capping machineries to synthesize functional mRNA. Novel applications of RNA capping enzymes in the discovery of new RNA species and sequencing the microbiome transcriptome will also be discussed. We will end with a summary of novel findings in RNA capping and the questions these findings pose.

  19. mRNA capping: biological functions and applications

    PubMed Central

    Ramanathan, Anand; Robb, G. Brett; Chan, Siu-Hong

    2016-01-01

    The 5′ m7G cap is an evolutionarily conserved modification of eukaryotic mRNA. Decades of research have established that the m7G cap serves as a unique molecular module that recruits cellular proteins and mediates cap-related biological functions such as pre-mRNA processing, nuclear export and cap-dependent protein synthesis. Only recently has the role of the cap 2′O methylation as an identifier of self RNA in the innate immune system against foreign RNA has become clear. The discovery of the cytoplasmic capping machinery suggests a novel level of control network. These new findings underscore the importance of a proper cap structure in the synthesis of functional messenger RNA. In this review, we will summarize the current knowledge of the biological roles of mRNA caps in eukaryotic cells. We will also discuss different means that viruses and their host cells use to cap their RNA and the application of these capping machineries to synthesize functional mRNA. Novel applications of RNA capping enzymes in the discovery of new RNA species and sequencing the microbiome transcriptome will also be discussed. We will end with a summary of novel findings in RNA capping and the questions these findings pose. PMID:27317694

  20. 31 CFR 50.90 - Cap on annual liability.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Cap on annual liability. 50.90 Section 50.90 Money and Finance: Treasury Office of the Secretary of the Treasury TERRORISM RISK INSURANCE PROGRAM Cap on Annual Liability § 50.90 Cap on annual liability. Pursuant to Section 103 of the Act,...

  1. 31 CFR 50.90 - Cap on annual liability.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false Cap on annual liability. 50.90 Section 50.90 Money and Finance: Treasury Office of the Secretary of the Treasury TERRORISM RISK INSURANCE PROGRAM Cap on Annual Liability § 50.90 Cap on annual liability. Pursuant to Section 103 of the Act,...

  2. 31 CFR 50.90 - Cap on annual liability.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance: Treasury 1 2012-07-01 2012-07-01 false Cap on annual liability. 50.90 Section 50.90 Money and Finance: Treasury Office of the Secretary of the Treasury TERRORISM RISK INSURANCE PROGRAM Cap on Annual Liability § 50.90 Cap on annual liability. Pursuant to Section 103 of the Act,...

  3. An Historical Look at a Contemporary Question: The Cervical Cap.

    ERIC Educational Resources Information Center

    Zimmet, Judy A.; Reagan, Patricia A.

    1986-01-01

    The history of the use of cervical caps as a birth control method is recounted in the areas of (1) revival of the cervical cap; (2) repopularization of the cervical cap; (3) empirical research; (4) nonbehavioral factors; (5) behavioral problems; and (6) health problems. (CB)

  4. Quantum three-body calculation of nonresonant triple-alpha reaction rate at low temperatures

    SciTech Connect

    Ogata, Kazuyuki; Kan, Masataka; Kamimura, Masayasu

    2010-06-01

    Triple-alpha reaction rate is re-evaluated by directly solving the three-body Schroedinger equation. The resonant and nonresonant processes are treated on the same footing using the continuum-discretized coupled-channels method for three-body scattering. An accurate description of the alpha-alpha nonresonant states significantly quenches the Coulomb barrier between the first two alpha-particles and the third alpha-particle. Consequently, the alpha-alpha nonresonant continuum states give a markedly larger contribution at low temperatures than that reported in previous studies. We show that Nomoto's method for three-body nonresonant capture processes, which is adopted in the NACRE compilation and many other studies, is a crude approximation of the accurate quantum three-body model calculation. We find an increase in triple-alpha reaction rate by 26 orders of magnitude around 10{sup 7} K compared with the rate of NACRE.

  5. Quantum three-body calculation of nonresonant triple-{alpha} reaction rate at low temperatures

    SciTech Connect

    Ogata, Kazuyuki; Kan, Masataka; Kamimura, Masayasu

    2010-08-12

    Triple-{alpha} reaction rate is re-evaluated by directly solving the three-body Schroedinger equation. The resonant and nonresonant processes are treated on the same footing using the continuum-discretized coupled-channels method for three-body scattering. An accurate description of the {alpha}-{alpha} nonresonant states significantly quenches the Coulomb barrier between the first two {alpha}-particles and the third {alpha}-particle. Consequently, the{alpha}-{alpha} nonresonant continuum states give a markedly larger contribution at low temperatures than that reported in previous studies. We show that Nomoto's method for three-body nonresonant capture processes, which is adopted in the NACRE compilation and many other studies, is a crude approximation of the accurate quantum three-body model calculation. We find an increase in triple-{alpha} reaction rate by about 20 orders of magnitude around 10{sup 7} K compared with the rate of NACRE.

  6. Variability of Mars' North Polar Water Ice Cap: I. Analysis of Mariner 9 and Viking Orbiter Imaging Data

    USGS Publications Warehouse

    Bass, D.S.; Herkenhoff, K. E.; Paige, D.A.

    2000-01-01

    Previous studies interpreted differences in ice coverage between Mariner 9 and Viking Orbiter observations of Mars' north residual polar cap as evidence of interannual variability of ice deposition on the cap. However, these investigators did not consider the possibility that there could be significant changes in the ice coverage within the northern residual cap over the course of the summer season. Our more comprehensive analysis of Mariner 9 and Viking Orbiter imaging data shows that the appearance of the residual cap does not show large-scale variance on an interannual basis. Rather we find evidence that regions that were dark at the beginning of summer look bright by the end of summer and that this seasonal variation of the cap repeats from year to year. Our results suggest that this brightening was due to the deposition of newly formed water ice on the surface. We find that newly formed ice deposits in the summer season have the same red-to-violet band image ratios as permanently bright deposits within the residual cap. We believe the newly formed ice accumulates in a continuous layer. To constrain the minimum amount of deposited ice, we used observed albedo data in conjunction with calculations using Mie theory for single scattering and a delta-Eddington approximation of radiative transfer for multiple scattering. The brightening could have been produced by a minimum of (1) a ???35-??m-thick layer of 50-??m-sized ice particles with 10% dust or (2) a ???14-??m-thick layer of 10-??m-sized ice particles with 50% dust. ?? 2000 Academic Press.

  7. Binding properties of aminophenyl carboxamide derivatives of the alpha/sub 2/-adrenergic receptor antagonists, rauwolscine and yohimbine: spatial and stereochemical considerations

    SciTech Connect

    Lanier, S.M.; Hess, H.J.; Grodsky, A.; Homcy, C.J.; Graham, R.M.

    1986-05-01

    The authors have recently characterized the radioiodinated analog of a carboxamide derivative of rauwolscine (RAU) (17 ..cap alpha..-hydroxy-20..cap alpha..-yohimban-16..beta..-(N-4-aminophenethyl)carboxamide) as a high-affinity probe for ..cap alpha../sub 2/-adrenergic receptors (..cap alpha../sub 2/-R). To investigate the spatial requirements of the receptor's ligand-binding site, the authors have synthesized carboxamide derivatives of RAU in which the aminophenyl group is separated from the parent compound by 0 (I), 2 (II) or 4 (III) atoms. In competition studies with /sup 3/H-RAU utilizing rat kidney membranes, I, RAU, II and III exhibited K/sub i/'s of 1.9 +/- 0.1, 4.7 +/- 0.2, 13 +/- 0.5 and 16 +/- 0.7 nM, respectively. The stereochemical requirements of the receptor's ligand binding site were also studied following the synthesis of similar carboxamide derivatives of yohimbine (YOH), a diastereoisomer of rauwolscine. In contrast to the high affinity observed with I and II, the corresponding derivatives of YOH exhibited 15 to 100-fold lower affinity. Iodination of I yields a radioligand (2175Ci/mmol) of high-affinity (K/sub D/ = 600pM) at the renal ..cap alpha../sub 2/-R and this compound should prove useful in biochemical studies of this ..cap alpha..-adrenergic receptor subtype. These data indicate that the spatial orientation of the aminophenyl substituent is an important determinant of high-affinity binding at ..cap alpha../sub 2/-R.

  8. The Phase Composition of Triton's Polar Caps.

    PubMed

    Duxbury, N S; Brown, R H

    1993-08-01

    Triton's polar caps are modeled as permanent nitrogen deposits hundreds of meters thick. Complex temperature variations on Triton's surface induce reversible transitions between the cubic and hexagonal phases of solid nitrogen, often with two coexisting propagating transition fronts. Subsurface temperature distributions are calculated using a two-dimensional thermal model with phase changes. The phase changes fracture the upper nitrogen layer, increasing its reflectivity and thus offering an explanation for the surprisingly high southern polar cap albedo (approximately 0.8) seen during the Voyager 2 flyby. The model has other implications for the phase transition phenomena on Triton, such as a plausible mechanism for the origin of geyser-like plume vent areas and a mechanism of energy transport toward them.

  9. The phase composition of Triton's polar caps

    NASA Technical Reports Server (NTRS)

    Duxbury, N. S.; Brown, R. H.

    1993-01-01

    Triton's polar caps are modeled as permanent nitrogen deposits hundreds of meters thick. Complex temperature variations on Triton's surface induce reversible transitions between the cubic and hexagonal phases of solid nitrogen, often with two coexisting propagating transition fronts. Subsurface temperature distributions are calculated using a two-dimensional thermal model with phase changes. The phase changes fracture the upper nitrogen layer, increasing its reflectivity and thus offering an explanation for the surprisingly high southern polar cap albedo (approximately 0.8) seen during the Voyager 2 flyby. The model has other implications for the phase transition phenomena on Triton, such as a plausible mechanism for the origin of geyser-like plume vent areas and a mechanism of energy transport toward them.

  10. The Phase Composition of Triton's Polar Caps.

    PubMed

    Duxbury, N S; Brown, R H

    1993-08-01

    Triton's polar caps are modeled as permanent nitrogen deposits hundreds of meters thick. Complex temperature variations on Triton's surface induce reversible transitions between the cubic and hexagonal phases of solid nitrogen, often with two coexisting propagating transition fronts. Subsurface temperature distributions are calculated using a two-dimensional thermal model with phase changes. The phase changes fracture the upper nitrogen layer, increasing its reflectivity and thus offering an explanation for the surprisingly high southern polar cap albedo (approximately 0.8) seen during the Voyager 2 flyby. The model has other implications for the phase transition phenomena on Triton, such as a plausible mechanism for the origin of geyser-like plume vent areas and a mechanism of energy transport toward them. PMID:17757213

  11. The phase composition of Triton's polar caps

    NASA Astrophysics Data System (ADS)

    Duxbury, N. S.; Brown, R. H.

    1993-08-01

    Triton's polar caps are modeled as permanent nitrogen deposits hundreds of meters thick. Complex temperature variations on Triton's surface induce reversible transitions between the cubic and hexagonal phases of solid nitrogen, often with two coexisting propagating transition fronts. Subsurface temperature distributions are calculated using a two-dimensional thermal model with phase changes. The phase changes fracture the upper nitrogen layer, increasing its reflectivity and thus offering an explanation for the surprisingly high southern polar cap albedo (approximately 0.8) seen during the Voyager 2 flyby. The model has other implications for the phase transition phenomena on Triton, such as a plausible mechanism for the origin of geyser-like plume vent areas and a mechanism of energy transport toward them.

  12. Process for making surfactant capped nanocrystals

    DOEpatents

    Alivisatos, A Paul; Rockenberger, Joerg

    2002-01-01

    Disclosed is a process for making surfactant capped nanocrystals of transition metal oxides. The process comprises reacting a metal cupferron complex of the formula M Cup, wherein M is a transition metal, and Cup is a cupferron, with a coordinating surfactant, the reaction being conducted at a temperature ranging from about 250 to about 300 C., for a period of time sufficient to complete the reaction.

  13. Morphology of Mars North Polar Ice Cap

    NASA Technical Reports Server (NTRS)

    Zwally, H. J.; Fountain, A.; Kargel, J.; Kouvaris, L.; Lewis, K.; MacAyeal, D.; Pfeffer, T.; Saba, J. L.

    2000-01-01

    The northern ice cap of Mars consists of a parabolic dome centered within 13 km of the pole, plus an arm-like ridge extending from the dome between about 135 and 225 east. Chasma Boreale lies between the dome and the extended ridge. The base of the dome is approximately elliptical with a major axis of 1100 km along the 90 east to 270 east direction and minor axis of 700 km along zero east to 180 deg. The heights of the dome and the extended ridge are respectively 2900 inches and 1700 inches above the surrounding basin. Least-squares fitting of a parabola through height profiles of the dome along longitudes 90 deg to 270 deg and zero deg to 180 deg gives an elliptic-paraboloid equation for the dome: Z(m) = 2800 - [(X-x)(exp 2)/113.6] - [(Y-y)(exp 2)/50.3], where X is the 90 deg to 270 deg axis, x = 9.90 km, y = 13.32 km, and the slightly-different fitted heights for the two axes are averaged. The center of the dome is shifted 13.32 km from the pole along zero deg longitude and 9.90 km along 90 deg longitude. Typical mean surface slopes on the ice cap are the order of 1/100 (0.6 deg), A small central portion of the cap, about 100 km by 200 km, extends in elevation about 200 inches above the parabolic shape of the cap. Additional information is contained in the original extended abstract.

  14. Mars South Polar Cap 'Fingerprint' Terrain

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This picture is illuminated by sunlight from the upper left.

    Some portions of the martian south polar residual cap have long, somewhat curved troughs instead of circular pits. These appear to form in a layer of material that may be different than that in which 'swiss cheese' circles and pits form, and none of these features has any analog in the north polar cap or elsewhere on Mars. This picture shows the 'fingerprint' terrain as a series of long, narrow depressions considered to have formed by collapse and widening by sublimation of ice. Unlike the north polar cap, the south polar region stays cold enough in summer to retain frozen carbon dioxide. Viking Orbiter observations during the late 1970s showed that very little water vapor comes off the south polar cap during summer, indicating that any frozen water that might be there remains solid throughout the year.

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image was obtained in early southern spring on August 4, 1999. It shows an area 3 x 5 kilometers (1.9 x 3.1 miles) at a resolution of about 7.3 meters (24 ft) per pixel. Located near 86.0oS, 53.9oW.

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  15. Kinetics of chaperoning of dithiothreitol-denatured alpha-lactalbumin by alpha-crystallin.

    PubMed

    Bettelheim, Frederick A

    2002-06-18

    Molecular chaperones prevent the aggregation of partially folded or misfolded forms of protein. alpha-Crystallin performs such a function in the ocular lens. Dynamic light scattering (DLS) measurements were performed to gain insight into the kinetics and mechanism of alpha-crystallin chaperoning. Experiments were conducted as a function of alpha-lactalbumin concentration as well as the alpha-crystallin/alpha-lactalbumin ratio over a 24 h period. In the particle distribution patterns the lactalbumin concentration was partitioned into three compartments: (a) monomeric free lactalbumin; (b) lactalbumin in the chaperoning complex; and (c) lactalbumin aggregates. DLS intensities were converted to molar concentrations by assuming a model of a spherical chaperoning complex. In the model, alpha-crystallin is the central core and alpha-lactalbumin molecules occupy a ring surrounding the core. The kinetics of chaperoning was studied by proposing a simple scheme with four rate constants. The reversible reaction of the formation of the chaperoning complex is characterized by rate constants k(1) and k(2). The rate constants k(3) and k(4) govern the irreversible aggregation of lactalbumin: the former from the free monomeric lactalbumin pool and the latter describing the aggregation of the denatured lactalbumin released from the chaperoning complex. The rate constants, k(3) and k(4) are four magnitudes larger than k(1) and k(2). The equilibrium constant of chaperoning complex formation lies in favor of the reactants. k(4) is somewhat faster than k(3) and it is three times faster than k(s) governing the self-aggregation of lactalbumin in the absence of alpha-crystallin.

  16. Lobe cell convection and polar cap precipitation

    NASA Astrophysics Data System (ADS)

    Eriksson, S.; Peria, W. J.; Bonnell, J. W.; Su, Y.-J.; Ergun, R. E.; Tung, Y.-K.; Parks, G. K.; Carlson, C. W.

    2003-05-01

    The characteristic electric and magnetic field signature of lobe cells as observed by the low-altitude FAST satellite in 55 dawn-dusk passes are compared with Polar ultraviolet images of polar cap auroral activity. Initial results from 34 events of UV image coverage suggest that there is an intimate coupling between the sunward convection flow of the lobe cell and transpolar auroral arcs or diffuse polar cap precipitation in ˜62% of these cases. However, in some cases where the field signatures are suggestive of lobe cell convection, there is no detectable particle precipitation either in Polar UVI or the FAST data sets. Moreover, the presence of lobe cells coincide with UV data intensifications in the premidnight 2000-2400 MLT sector and/or the postnoon 1500 MLT region in ˜59% of all cases with UVI coverage. The magnetic local time dependence of the lobe cells and polar cap precipitation on the interplanetary magnetic field (IMF) are examined using the upstream Wind monitor. The relative importance of the IMF By and Bz components are investigated and compared with the predictions of the antiparallel merging model and strongly suggests a connection with the magnetospheric sash, as is further implied by the mapping of magnetic field lines using the [2002] (T01) model. It was also noted that a majority of lobe cell events occurred during enhanced AE index substorm-like conditions and that generally stronger AE indices are measured for stronger IMF By magnitudes during these events.

  17. Lobe Cell Convection and Polar cap Precipitation

    NASA Astrophysics Data System (ADS)

    Eriksson, S.; Peria, W. J.; Su, Y.; Ergun, R. E.; Tung, Y.; Parks, G.; Carlson, C. W.

    2002-12-01

    The characteristic electric and magnetic field signature of lobe cells as observed by the low-altitude FAST satellite are compared with Polar ultraviolet images of polar cap auroral activity. Initial results from 55 events suggest that there is an intimate coupling between the sunward convection flow of the lobe cell and transpolar auroral arcs or diffuse polar cap precipitation. Moreover, the presence of lobe cells coincide with UV data intensifications in the premidnight 2100-2400 MLT sector and/or the postnoon 1500 MLT region in ~54% of all cases with UVI coverage. The magnetic local time dependence of the lobe cells and polar cap precipitation on the interplanetary magnetic field (IMF) are examined using the upstream Wind monitor. The relative importance of the IMF By and Bz components are investigated and compared with the predictions of the antiparallel merging model and strongly suggests a connection with the magnetospheric sash, as is further implied by the mapping of magnetic field lines using the Tsyganenko [2002] (T01) model. It was also noted that a majority of events occurred during enhanced AE index substorm-like conditions and that generally stronger AE indices are measured for stronger IMF By magnitudes.

  18. MycoCAP - Mycobacterium Comparative Analysis Platform

    PubMed Central

    Choo, Siew Woh; Ang, Mia Yang; Dutta, Avirup; Tan, Shi Yang; Siow, Cheuk Chuen; Heydari, Hamed; Mutha, Naresh V. R.; Wee, Wei Yee; Wong, Guat Jah

    2015-01-01

    Mycobacterium spp. are renowned for being the causative agent of diseases like leprosy, Buruli ulcer and tuberculosis in human beings. With more and more mycobacterial genomes being sequenced, any knowledge generated from comparative genomic analysis would provide better insights into the biology, evolution, phylogeny and pathogenicity of this genus, thus helping in better management of diseases caused by Mycobacterium spp.With this motivation, we constructed MycoCAP, a new comparative analysis platform dedicated to the important genus Mycobacterium. This platform currently provides information of 2108 genome sequences of at least 55 Mycobacterium spp. A number of intuitive web-based tools have been integrated in MycoCAP particularly for comparative analysis including the PGC tool for comparison between two genomes, PathoProT for comparing the virulence genes among the Mycobacterium strains and the SuperClassification tool for the phylogenic classification of the Mycobacterium strains and a specialized classification system for strains of Mycobacterium abscessus. We hope the broad range of functions and easy-to-use tools provided in MycoCAP makes it an invaluable analysis platform to speed up the research discovery on mycobacteria for researchers. Database URL: http://mycobacterium.um.edu.my PMID:26666970

  19. Comparison of Detector Technologies for CAPS

    NASA Technical Reports Server (NTRS)

    Stockum, Jana L.

    2005-01-01

    In this paper, several different detectors are examined for use in a Comet/Asteroid Protection System (CAPS), a conceptual study for a possible future space-based system. Each detector will be examined for its future (25 years or more in the future) ability to find and track near-Earth Objects (NEOs) from a space-based detection platform. Within the CAPS study are several teams of people who each focus on different aspects of the system concept. This study s focus is on detection devices. In particular, evaluations on the following devices have been made: charge-coupled devices (CCDs), charge-injected devices (CIDs), superconducting tunneling junctions (STJs), and transition edge sensors (TESs). These devices can be separated into two main categories; the first category includes detectors that are currently being widely utilized, such as CCDs and CIDs. The second category includes experimental detectors, such as STJs and TESs. After the discussion of the detectors themselves, there will be a section devoted to the explicit use of these detectors with CAPS.

  20. Protein synthesis in geostimulated root caps

    NASA Technical Reports Server (NTRS)

    Feldman, L. J.

    1982-01-01

    A study is presented of the processes occurring in the root cap of corn which are requisite for the formation of root cap inhibitor and which can be triggered or modulated by both light and gravity. The results of this study indicate the importance of protein synthesis for light-induced gravitropic bending in roots. Root caps in which protein synthesis is prevented are unable to induce downward bending. This suggests that light acts by stimulating proteins which are necessary for the translation of the gravitropic stimulus into a growth response (downward bending). The turnover of protein with time was also examined in order to determine whether light acts by stimulating the synthesis of unique proteins required for downward growth. It is found that auxin in combination with light allows for the translation of the gravitropic stimulus into a growth response at least in part through the modification of protein synthesis. It is concluded that unique proteins are stimulated by light and are involved in promoting the downward growth in roots which are responding to gravity.

  1. MycoCAP - Mycobacterium Comparative Analysis Platform.

    PubMed

    Choo, Siew Woh; Ang, Mia Yang; Dutta, Avirup; Tan, Shi Yang; Siow, Cheuk Chuen; Heydari, Hamed; Mutha, Naresh V R; Wee, Wei Yee; Wong, Guat Jah

    2015-01-01

    Mycobacterium spp. are renowned for being the causative agent of diseases like leprosy, Buruli ulcer and tuberculosis in human beings. With more and more mycobacterial genomes being sequenced, any knowledge generated from comparative genomic analysis would provide better insights into the biology, evolution, phylogeny and pathogenicity of this genus, thus helping in better management of diseases caused by Mycobacterium spp.With this motivation, we constructed MycoCAP, a new comparative analysis platform dedicated to the important genus Mycobacterium. This platform currently provides information of 2108 genome sequences of at least 55 Mycobacterium spp. A number of intuitive web-based tools have been integrated in MycoCAP particularly for comparative analysis including the PGC tool for comparison between two genomes, PathoProT for comparing the virulence genes among the Mycobacterium strains and the SuperClassification tool for the phylogenic classification of the Mycobacterium strains and a specialized classification system for strains of Mycobacterium abscessus. We hope the broad range of functions and easy-to-use tools provided in MycoCAP makes it an invaluable analysis platform to speed up the research discovery on mycobacteria for researchers. Database URL: http://mycobacterium.um.edu.my.

  2. The alpha channeling effect

    SciTech Connect

    Fisch, N. J.

    2015-12-10

    Alpha particles born through fusion reactions in a tokamak reactor tend to slow down on electrons, but that could take up to hundreds of milliseconds. Before that happens, the energy in these alpha particles can destabilize on collisionless timescales toroidal Alfven modes and other waves, in a way deleterious to energy confinement. However, it has been speculated that this energy might be instead be channeled into useful energy, so as to heat fuel ions or to drive current. Such a channeling needs to be catalyzed by waves Waves can produce diffusion in energy of the alpha particles in a way that is strictly coupled to diffusion in space. If these diffusion paths in energy-position space point from high energy in the center to low energy on the periphery, then alpha particles will be cooled while forced to the periphery. The energy from the alpha particles is absorbed by the wave. The amplified wave can then heat ions or drive current. This process or paradigm for extracting alpha particle energy collisionlessly has been called alpha channeling. While the effect is speculative, the upside potential for economical fusion is immense. The paradigm also operates more generally in other contexts of magnetically confined plasma.

  3. Tunable plasmonic characteristics at asymmetric double metal caps on a dielectric nanosphere

    NASA Astrophysics Data System (ADS)

    Yun, Hansik; Park, Hyeonsoo; Lee, Byoungho

    2015-07-01

    The plasmonics is expected to be a potential candidate of future sensing technologies, such as single-molecular detections and surface-enhanced Raman scattering, because of concentrated and enhanced electric fields at a sharp edge of a metallic nanostructure. In particular, breaking symmetry of a plasmonic structure results in anisotropic angular optical responses and allows a broad tunability of surface plasmons. In this study, we suggest a structure of asymmetric double metal caps on a dielectric nanosphere in order to increase the asymmetry of component structures and to improve the tunability of a plasmonic sensor.

  4. Facile biosynthesis of phosphate capped gold nanoparticles by a bacterial isolate Stenotrophomonas maltophilia

    NASA Astrophysics Data System (ADS)

    Nangia, Yogesh; Wangoo, Nishima; Sharma, Saurabh; Wu, Jin-Song; Dravid, Vinayak; Shekhawat, G. S.; Raman Suri, C.

    2009-06-01

    We report intracellular biosynthesis of gold nanoparticles (GNPs) by a strain Stenotrophomonas maltophilia (AuRed02) isolated from the soil samples of Singhbhum gold mines, India. An aqueous solution of gold chloride was reduced to metallic gold in a suspension of disrupted cell mass of AuRed02, which progressively turns into cherry red within 8 h of incubation at 25 °C. The optical spectrum showed the plasmon resonance at 530 nm and analysis by transmission electron microscopy and dynamic light scattering confirmed the formation of around 40 nm GNPs. Zeta potential and Fourier transform infrared measurements confirmed GNPs are capped by negatively charged phosphate groups of NADP.

  5. Facile biosynthesis of phosphate capped gold nanoparticles by a bacterial isolate Stenotrophomonas maltophilia

    SciTech Connect

    Nangia, Yogesh; Wangoo, Nishima; Raman Suri, C.; Sharma, Saurabh; Wu, J.-S.; Dravid, Vinayak; Shekhawat, G. S.

    2009-06-08

    We report intracellular biosynthesis of gold nanoparticles (GNPs) by a strain Stenotrophomonas maltophilia (AuRed02) isolated from the soil samples of Singhbhum gold mines, India. An aqueous solution of gold chloride was reduced to metallic gold in a suspension of disrupted cell mass of AuRed02, which progressively turns into cherry red within 8 h of incubation at 25 deg. C. The optical spectrum showed the plasmon resonance at 530 nm and analysis by transmission electron microscopy and dynamic light scattering confirmed the formation of around 40 nm GNPs. Zeta potential and Fourier transform infrared measurements confirmed GNPs are capped by negatively charged phosphate groups of NADP.

  6. What Lies Below a Martian Ice Cap

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for larger annotated version

    This image (top) taken by the Shallow Radar instrument on NASA's Mars Reconnaissance Orbiter reveals the layers of ice, sand and dust that make up the north polar ice cap on Mars. It is the most detailed look to date at the insides of this ice cap. The colored map below the radar picture shows the topography of the corresponding Martian terrain (red and white represent higher ground, and green and yellow lower).

    The radar image reveals four never-before-seen thick layers of ice and dust separated by layers of nearly pure ice. According to scientists, these thick ice-free layers represent approximately one-million-year-long cycles of climate change on Mars caused by variations in the planet's tilted axis and its eccentric orbit around the sun. Adding up the entire stack of ice gives an estimated age for the north polar ice cap of about 4 million years a finding that agrees with previous theoretical estimates. The ice cap is about 2 kilometers (1.2 miles) thick.

    The radar picture also shows that the boundary between the ice layers and the surface of Mars underneath is relatively flat (bottom white line on the right). This implies that the surface of Mars is not sagging, or bending, under the weight of the ice cap and this, in turn, suggests that the planet's lithosphere, a combination of the crust and the strong parts of the upper mantle, is thicker than previously thought.

    A thicker lithosphere on Mars means that temperatures increase more gradually with depth toward the interior. Temperatures warm enough for water to be liquid are therefore deeper than previously thought. Likewise, if liquid water does exist in aquifers below the surface of Mars, and if there are any organisms living in that water, they would have to be located deeper in the planet.

    The topography data are from Mars Orbiter Laser Altimeter, which was flown on NASA's Mars Global

  7. Cap buckling as a potential mechanism of atherosclerotic plaque vulnerability.

    PubMed

    Abdelali, Maria; Reiter, Steven; Mongrain, Rosaire; Bertrand, Michel; L'Allier, Philippe L; Kritikou, Ekaterini A; Tardif, Jean-Claude

    2014-04-01

    Plaque rupture in atherosclerosis is the primary cause of potentially deadly coronary events, yet about 40% of ruptures occur away from the plaque cap shoulders and cannot be fully explained with the current biomechanical theories. Here, cap buckling is considered as a potential destabilizing factor which increases the propensity of the atherosclerotic plaque to rupture and which may also explain plaque failure away from the cap shoulders. To investigate this phenomenon, quasistatic 2D finite element simulations are performed, considering the salient geometrical and nonlinear material properties of diverse atherosclerotic plaques over the range of physiological loads. The numerical results indicate that buckling may displace the location of the peak von Mises stresses in the deflected caps. Plaque buckling, together with its deleterious effects is further observed experimentally in plaque caps using a physical model of deformable mock coronary arteries with fibroatheroma. Moreover, an analytical approach combining quasistatic equilibrium equations with the Navier-Bresse formulas is used to demonstrate the buckling potential of a simplified arched slender cap under intraluminal pressure and supported by foundations. This analysis shows that plaque caps - calcified, fibrotic or cellular - may buckle in specific undulated shapes once submitted to critical loads. Finally, a preliminary analysis of intravascular ultrasonography recordings of patients with atherosclerotic coronary arteries corroborates the numerical, experimental and theoretical findings and shows that various plaque caps buckle in vivo. By displacing the sites of high stresses in the plaque cap, buckling may explain the atherosclerotic plaque cap rupture at various locations, including cap shoulders.

  8. Purification, characterization, and immunofluorescence localization of Saccharomyces cerevisiae capping protein.

    PubMed

    Amatruda, J F; Cooper, J A

    1992-06-01

    Capping protein binds the barbed ends of actin filaments and nucleates actin filament assembly in vitro. We purified capping protein from Saccharomyces cervisiae. One of the two subunits is the product of the CAP2 gene, which we previously identified as the gene encoding the beta subunit of capping protein based on its sequence similarity to capping protein beta subunits in chicken and Dictyostelium (Amatruda, J. F., J. F. Cannon, K. Tatchell, C. Hug, and J. A. Cooper. 1990. Nature (Lond.) 344:352-354). Yeast capping protein has activity in critical concentration and low-shear viscometry assays consistent with barbed-end capping activity. Like chicken capping protein, yeast capping protein is inhibited by PIP2. By immunofluorescence microscopy yeast capping protein colocalizes with cortical actin spots at the site of bud emergence and at the tips of growing buds and shmoos. In contrast, capping protein does not colocalize with actin cables or with actin rings at the site of cytokinesis. PMID:1315784

  9. Human recombinant cementum attachment protein (hrPTPLa/CAP) promotes hydroxyapatite crystal formation in vitro and bone healing in vivo.

    PubMed

    Montoya, Gonzalo; Arenas, Jesús; Romo, Enrique; Zeichner-David, Margarita; Alvarez, Marco; Narayanan, A Sampath; Velázquez, Ulises; Mercado, Gabriela; Arzate, Higinio

    2014-12-01

    Cementum extracellular matrix is similar to other mineralized tissues; however, this unique tissue contains molecules only present in cementum. A cDNA of these molecules, cementum attachment protein (hrPTPLa/CAP) was cloned and expressed in a prokaryotic system. This molecule is an alternative splicing of protein tyrosine phosphatase-like A (PTPLa). In this study, we wanted to determine the structural and functional characteristics of this protein. Our results indicate that hrPTPLa/CAP contains a 43.2% α-helix, 8.9% β-sheet, 2% β-turn and 45.9% random coil secondary structure. Dynamic light scattering shows that this molecule has a size distribution of 4.8 nm and aggregates as an estimated mass of 137 kDa species. AFM characterization and FE-SEM studies indicate that this protein self-assembles into nanospheres with sizes ranging from 7.0 to 27 nm in diameter. Functional studies demonstrate that hrPTPLa/CAP promotes hydroxyapatite crystal nucleation: EDS analysis revealed that hrPTPLa/CAP-induced crystals had a 1.59 ± 0.06 Ca/P ratio. Further confirmation with MicroRaman spectrometry and TEM confirm the presence of hydroxyapatite. In vivo studies using critical-size defects in rat cranium showed that hrPTPLa/CAP promoted 73% ± 2.19% and 87% ± 1.97% new bone formation at 4 and 8 weeks respectively. Although originally identified in cementum, PTPLa/CAP is very effective at inducing bone repair and healing and therefore this novel molecule has a great potential to be used for mineralized tissue bioengineering and tissue regeneration. PMID:25263524

  10. Human recombinant cementum attachment protein (hrPTPLa/CAP) promotes hydroxyapatite crystal formation in vitro and bone healing in vivo.

    PubMed

    Montoya, Gonzalo; Arenas, Jesús; Romo, Enrique; Zeichner-David, Margarita; Alvarez, Marco; Narayanan, A Sampath; Velázquez, Ulises; Mercado, Gabriela; Arzate, Higinio

    2014-12-01

    Cementum extracellular matrix is similar to other mineralized tissues; however, this unique tissue contains molecules only present in cementum. A cDNA of these molecules, cementum attachment protein (hrPTPLa/CAP) was cloned and expressed in a prokaryotic system. This molecule is an alternative splicing of protein tyrosine phosphatase-like A (PTPLa). In this study, we wanted to determine the structural and functional characteristics of this protein. Our results indicate that hrPTPLa/CAP contains a 43.2% α-helix, 8.9% β-sheet, 2% β-turn and 45.9% random coil secondary structure. Dynamic light scattering shows that this molecule has a size distribution of 4.8 nm and aggregates as an estimated mass of 137 kDa species. AFM characterization and FE-SEM studies indicate that this protein self-assembles into nanospheres with sizes ranging from 7.0 to 27 nm in diameter. Functional studies demonstrate that hrPTPLa/CAP promotes hydroxyapatite crystal nucleation: EDS analysis revealed that hrPTPLa/CAP-induced crystals had a 1.59 ± 0.06 Ca/P ratio. Further confirmation with MicroRaman spectrometry and TEM confirm the presence of hydroxyapatite. In vivo studies using critical-size defects in rat cranium showed that hrPTPLa/CAP promoted 73% ± 2.19% and 87% ± 1.97% new bone formation at 4 and 8 weeks respectively. Although originally identified in cementum, PTPLa/CAP is very effective at inducing bone repair and healing and therefore this novel molecule has a great potential to be used for mineralized tissue bioengineering and tissue regeneration.

  11. Biocompatible capped iron oxide nanoparticles for Vibrio cholerae detection

    NASA Astrophysics Data System (ADS)

    Sharma, Anshu; Baral, Dinesh; Rawat, Kamla; Solanki, Pratima R.; Bohidar, H. B.

    2015-05-01

    We report the studies relating to fabrication of an efficient immunosensor for Vibrio cholerae detection. Magnetite (iron oxide (Fe3O4)) nanoparticles (NPs) have been synthesized by the co-precipitation method and capped by citric acid (CA). These NPs were electrophoretically deposited onto indium-tin-oxide (ITO)-coated glass substrate and used for immobilization of monoclonal antibodies against Vibrio cholerae (Ab) and bovine serum albumin (BSA) for Vibrio cholerae detection using an electrochemical technique. The structural and morphological studies of Fe3O4 and CA-Fe3O4/ITO were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and dynamic light scattering (DLS) techniques. The average crystalline size of Fe3O4, CA-Fe3O4 nanoparticles obtained were about 29 ± 1 nm and 37 ± 1 nm, respectively. The hydrodynamic radius of the nanoparticles was found to be 77.35 nm (Fe3O4) and 189.51 nm (CA-Fe3O4) by DLS measurement. The results of electrochemical response studies of the fabricated BSA/Ab/CA-Fe2O3/ITO immunosensor exhibits a good detection range of 12.5-500 ng mL-1 with a low detection limit of 0.32 ng mL-1, sensitivity 0.03 Ω/ng ml-1 cm-2, and reproducibility more than 11 times.

  12. Biocompatible capped iron oxide nanoparticles for Vibrio cholerae detection.

    PubMed

    Sharma, Anshu; Baral, Dinesh; Rawat, Kamla; Solanki, Pratima R; Bohidar, H B

    2015-05-01

    We report the studies relating to fabrication of an efficient immunosensor for Vibrio cholerae detection. Magnetite (iron oxide (Fe(3)O(4))) nanoparticles (NPs) have been synthesized by the co-precipitation method and capped by citric acid (CA). These NPs were electrophoretically deposited onto indium-tin-oxide (ITO)-coated glass substrate and used for immobilization of monoclonal antibodies against Vibrio cholerae (Ab) and bovine serum albumin (BSA) for Vibrio cholerae detection using an electrochemical technique. The structural and morphological studies of Fe(3)O(4) and CA-Fe(3)O(4)/ITO were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and dynamic light scattering (DLS) techniques. The average crystalline size of Fe(3)O(4), CA-Fe(3)O(4) nanoparticles obtained were about 29 ± 1 nm and 37 ± 1 nm, respectively. The hydrodynamic radius of the nanoparticles was found to be 77.35 nm (Fe(3)O(4)) and 189.51 nm (CA-Fe(3)O(4)) by DLS measurement. The results of electrochemical response studies of the fabricated BSA/Ab/CA-Fe(2)O(3)/ITO immunosensor exhibits a good detection range of 12.5-500 ng mL(-1) with a low detection limit of 0.32 ng mL(-1), sensitivity 0.03 Ω/ng ml(-1) cm(-2), and reproducibility more than 11 times.

  13. Alkanethiol capping-induced changes in the magnetoresistance of Co

    NASA Astrophysics Data System (ADS)

    Knaus, Brad; Garzon, Samir; Crawford, Thomas M.

    2008-03-01

    We demonstrate that chemisorption of a ˜ 1 nm thick dodecanethiol (C12H25SH) self-assembled monolayer on the surface of an Au film alters the magnetotransport of an underlying Co film. Giant paramagnetism has been previously detected in Au thin films and nanoparticles capped with alkanethiols via SQUID magnetometry. By observing the impact of Au-thiol magnetism on a ferromagnetic thin film we avoid background subtraction and the influence of impurities. After thiolation, significant changes are observed in the anisotropic magnetoresistance (AMR) and planar Hall effect (PHE) from Co/Au bilayers (30 nm/5-60 nm) patterned into 1 x 5 mm^2 bars. Driven with nearly perpendicular external fields, we observed domain nucleation shifts of ˜0.65 T and changes in the FWHM of the AMR. We have also measured differences in the MR as a function of ambient exposure time presumably due to oxidation effects known to occur in alkanethiols. Effects of surface scattering were eliminated with the introduction of a 12nm Al2O3 insulation barrier between Co and Au. We have calculated that the effects of magnetostriction are too small by more than two orders of magnitude to explain our observations. We therefore hypothesize that Au-thiol magnetization acts as a source of magnetic field which biases the underlying Co film.

  14. Identification of an endogenous alpha-adrenergic receptor antagonist: studies on its possible role in endocrine and cardiovascular function

    SciTech Connect

    Dunbar, J.C.; Wider, M.; House, F.; Campbell, R.

    1986-03-01

    The concept of ..cap alpha.. and ..beta.. adrenergic receptors that are regulated by epinephrine or norepinephrine (NE) is well established. The reported receptor antagonists have been synthetic. A peptide extracted from the duodenal mucosa with ..cap alpha..-2 antagonist properties has been identified. It specifically inhibits /sup 3/H-yohimbine binding (..cap alpha..-2) but not /sup 3/H dihydroalprenolol (..beta..) binding in whole brain membranes. Partially purified preparations of the alpha receptor binding inhibitor (ABI) were tested for endocrine pancreatic and cardiovascular effects. When isolated islets were incubated in the presence of ABI with and without NE, ABI along did not alter insulin secretion but completely reversed the NE suppression of glucose stimulated insulin release. Glucagon secretion by these same islets was enhanced by ABI and augmented the stimulatory effect of NE. Intravenous (I.V.) infusion of ABI increased serum insulin in the presence of NE and decreased the serum glucose response to a glucose load. Infusion of ABI into the 4th ventricle, or I.V. resulted in a decrease (50-60%) in systolic and diastolic blood pressure as well as a decrease (10-20%) in heart rate. From these studies the authors conclude that a duodenal peptide with the capacity to inhibit ..cap alpha..-2 agonist binding may play a role in endocrine and cardiovascular functions.

  15. Jet production in deep inelastic scattering at HERA

    SciTech Connect

    Sutton, M. R.

    2006-04-11

    A number of the most recent results from the wealth of precision HERA data on high transverse energy jet production in deep inelastic scattering are reviewed. These measurements are confronted with predictions from next-to-leading order (NLO) Quantum Chromodynamics and allow the extraction of the strong coupling constant, {alpha}s, and have been used in QCD fits of the parton distribution functions in the proton.

  16. Scatter of elastic waves by a thin flat elliptical inhomogeneity

    NASA Technical Reports Server (NTRS)

    Fu, L. S.

    1983-01-01

    Elastodynamic fields of a single, flat, elliptical inhomogeneity embedded in an infinite elastic medium subjected to plane time harmonic waves are studied. Scattered displacement amplitudes and stress intensities are obtained in series form for an incident wave in an arbitrary direction. The cases of a penny shaped crack and an elliptical crack are given as examples. The analysis is valid for alpha a up to about two, where alpha is longitudinal wave number and a is a typical geometric parameter.

  17. Alpha One Foundation

    MedlinePlus

    ... related programs More News Our Number One Goal: Find a cure for Alpha-1. Website Sponsors Helpful Links 3300 Ponce de Leon Blvd. Coral Gables, FL 33134 Phone: (877) 228-7321 Email: info@alphaone.org Copyright ...

  18. Cold atmospheric plasma (CAP) changes gene expression of key molecules of the wound healing machinery and improves wound healing in vitro and in vivo.

    PubMed

    Arndt, Stephanie; Unger, Petra; Wacker, Eva; Shimizu, Tetsuji; Heinlin, Julia; Li, Yang-Fang; Thomas, Hubertus M; Morfill, Gregor E; Zimmermann, Julia L; Bosserhoff, Anja-Katrin; Karrer, Sigrid

    2013-01-01

    Cold atmospheric plasma (CAP) has the potential to interact with tissue or cells leading to fast, painless and efficient disinfection and furthermore has positive effects on wound healing and tissue regeneration. For clinical implementation it is necessary to examine how CAP improves wound healing and which molecular changes occur after the CAP treatment. In the present study we used the second generation MicroPlaSter ß® in analogy to the current clinical standard (2 min treatment time) in order to determine molecular changes induced by CAP using in vitro cell culture studies with human fibroblasts and an in vivo mouse skin wound healing model. Our in vitro analysis revealed that the CAP treatment induces the expression of important key genes crucial for the wound healing response like IL-6, IL-8, MCP-1, TGF-ß1, TGF-ß2, and promotes the production of collagen type I and alpha-SMA. Scratch wound healing assays showed improved cell migration, whereas cell proliferation analyzed by XTT method, and the apoptotic machinery analyzed by protein array technology, was not altered by CAP in dermal fibroblasts. An in vivo wound healing model confirmed that the CAP treatment affects above mentioned genes involved in wound healing, tissue injury and repair. Additionally, we observed that the CAP treatment improves wound healing in mice, no relevant side effects were detected. We suggest that improved wound healing might be due to the activation of a specified panel of cytokines and growth factors by CAP. In summary, our in vitro human and in vivo animal data suggest that the 2 min treatment with the MicroPlaSter ß® is an effective technique for activating wound healing relevant molecules in dermal fibroblasts leading to improved wound healing, whereas the mechanisms which contribute to these observed effects have to be further investigated.

  19. Debye series for light scattering by a coated nonspherical particle

    SciTech Connect

    Xu Feng; Lock, James A.

    2010-06-15

    By using the extended boundary condition method, the Debye series is developed for light scattered by a coated nonspherical particle in order to interpret the angular dependence of the scattered intensity in terms of various physical processes. Numerical calculations are performed to study the influence of the coating thickness and the ellipticity of a coated spheroid on the angular position of the {alpha} and {beta} primary rainbows, which are produced by partial waves experiencing one internal reflection. The hyperbolic umbilic focal section is demonstrated and is analyzed for both the {alpha} and the {beta} rainbows.

  20. Alpha Particle Diagnostic

    SciTech Connect

    Fisher, Ray, K.

    2009-05-13

    The study of burning plasmas is the next frontier in fusion energy research, and will be a major objective of the U.S. fusion program through U.S. collaboration with our international partners on the ITER Project. For DT magnetic fusion to be useful for energy production, it is essential that the energetic alpha particles produced by the fusion reactions be confined long enough to deposit a significant fraction of their initial ~3.5 MeV energy in the plasma before they are lost. Development of diagnostics to study the behavior of energetic confined alpha particles is a very important if not essential part of burning plasma research. Despite the clear need for these measurements, development of diagnostics to study confined the fast confined alphas to date has proven extremely difficult, and the available techniques remain for the most part unproven and with significant uncertainties. Research under this grant had the goal of developing diagnostics of fast confined alphas, primarily based on measurements of the neutron and ion tails resulting from alpha particle knock-on collisions with the plasma deuterium and tritium fuel ions. One of the strengths of this approach is the ability to measure the alphas in the hot plasma core where the interesting ignition physics will occur.

  1. Decoupling single nanowire mobilities limited by surface scattering and bulk impurity scattering

    SciTech Connect

    Khanal, D. R.; Levander, A. X.; Wu, J.; Yu, K. M.; Liliental-Weber, Z.; Walukiewicz, W.; Grandal, J.; Sanchez-Garcia, M. A.; Calleja, E.

    2011-08-01

    We demonstrate the isolation of two free carrier scattering mechanisms as a function of radial band bending in InN nanowires via universal mobility analysis, where effective carrier mobility is measured as a function of effective electric field in a nanowire field-effect transistor. Our results show that Coulomb scattering limits effective mobility at most effective fields, while surface roughness scattering only limits mobility under very high internal electric fields. High-energy {alpha} particle irradiation is used to vary the ionized donor concentration, and the observed decrease in mobility and increase in donor concentration are compared to Hall effect results of high-quality InN thin films. Our results show that for nanowires with relatively high doping and large diameters, controlling Coulomb scattering from ionized dopants should be given precedence over surface engineering when seeking to maximize nanowire mobility.

  2. Detection system for a gas chromatograph. [. cap alpha. -methylnaphthalene,. beta. -methylnapthalene

    DOEpatents

    Hayes, J.M.; Small, G.J.

    1982-04-26

    A method and apparatus are described for the quantitative analysis of vaporizable compounds, and in particular of polycyclic aromatic hydrocarbons which may be induced to fluoresce. The sample to be analyzed is injected into a gas chromatography column and is eluted through a narrow orifice into a vacuum chamber. The free expansion of the eluted sample into the vacuum chamber creates a supersonic molecular beam in which the sample molecules are cooled to the extent that the excited vibrational and rotational levels are substantially depopulated. The cooled molecules, when induced to fluoresce by laser excitation, give greatly simplified spectra suitable for analytical purposes. The laser induced fluorimetry provides great selectivity, and the gas chromatograph provides quantitative transfer of the sample to the molecular beam. 3 figures, 2 tables.

  3. Cytostatic effect of L-lysine-. cap alpha. -oxidase from Trichoderma harzianum Rifai and Trichoderma viride

    SciTech Connect

    Khaduev, S.Kh.; Zhukova, O.S.; Dobrynin, Ya.V.; Soda, K.; Berezov, T.T.

    1987-09-01

    Comparative data is given on the effect of the new antitumor enzyme LO, obtained from a Soviet strain of Trichoderma harzianum Rifai and from Trichoderma viride from Japan, on DNA and RNA synthesis in human ovarian carcinoma cells in culture and also the results of the action of LO from Tr. harzianum Rifai on protein synthesis. Specific precursors were added to the samples 1 hour before the end of incubation time: /sup 3/H-thymidine, the precursor for DNA synthesis, /sup 3/H-uridine for RNA synthesis, and /sup 3/H-leucine for protein synthesis.

  4. Biodistribution and metabolism of 16. cap alpha. -((/sup 18/F)-fluoro)-17. beta. -estradiol

    SciTech Connect

    Mathias, C.J.; Brodack, J.W.; Kilbourn, M.R.; Carlson, K.A.; Katzenellenbogen, J.A.; Welch, M.J.

    1985-05-01

    The uptake of receptor-mediated radiopharmaceuticals as measured by target to non-target uptake ratios depends upon many parameters. These include blood flow to the tissue, blood volume, receptor concentration as well as metabolism of the tracer. In a rat tumor model (DMBA) induced mammary tumors with high concentration of estrogen receptors) uptake of /sup 18/F-estradiol was studied while blood flow was measured with the use of /sup 125/I-iodoantipyrine, blood volume was measured with the use of /sup 99m/Tc-labeled red blood cells, and the receptor concentration by in vitro assay. The results demonstrate no correlation between blood flow and uptake of ligand, or between receptor concentration and uptake of ligand. No correlation existed between blood volume and uptake or /sup 18/F-estradiol, even though the blood volume varied by a factor of --20 in the tumors studied. The distribution of the fluorine-18 may depend upon metabolites of the ligand rather than the ligand itself. The authors have developed a technique to separate metabolites from the administered compound in blood and tissues. The distribution of the compound in the blood at times >30 mins after injection was primarily within the red blood cells in a chemical form that was not extractable even in lysed blood samples. By injecting blood from one rate into another the authors have shown that the activity in blood 2 hours after injection of /sup 18/F-estradiol is not available for uptake in receptor rich tissue but remains in the blood and non-target tissues.

  5. Effects of zinc, copper, and lead toxicity on. cap alpha. -aminolevulinic acid dehydratase activity. [Rats

    SciTech Connect

    Shafiq-ur-Rehman

    1984-07-01

    The distribution of lead, zinc and copper in the human environment has been recognized as a major toxicological factor. Lead ions have been shown to inhibit the activity of delta-aminolevulinic acid dehydratase (delta-ALAD), which is involved in the biosynthesis of heme. Copper also has its inhibitory effect on delta-ALAD activity. A study has shown that the delta-ALAD was activated by zinc ions at physiological concentrations. In view of these reports, it was considered worthwhile to study the poisoning effects of lead, zinc and copper on delta-ALAD activity along with the concentrations of these metal ions in the blood. A possible role of Zn/sup + +/, Cu/sup + +/, and Pb/sup + +/ interaction and their influence on delta-ALAD has been explored in the present paper.

  6. Phosphogypsum capping depth affects revegetation and hydrology in Western Canada.

    PubMed

    Jackson, Mallory E; Naeth, M Anne; Chanasyk, David S; Nichol, Connie K

    2011-01-01

    Phosphogypsum (PG), a byproduct of phosphate fertilizer manufacturing, is commonly stacked and capped with soil at decommissioning. Shallow (0, 8, 15, and 30 cm) and thick (46 and 91 cm) sandy loam caps on a PG stack near Fort Saskatchewan, Alberta, Canada, were studied in relation to vegetation establishment and hydrologic properties. Plant response was evaluated over two growing seasons for redtop ( L.), slender wheatgrass ( (Link) Malte ex H.F. Lewis), tufted hairgrass ( (L.) P. Beauv.), and sheep fescue ( L.) and for a mix of these grasses with alsike clover ( L.). Water content below the soil-PG interface was monitored with time-domain reflectometry probes, and leachate water quantity and quality at a depth of 30 cm was measured using lysimeters. Vegetation responded positively to all cap depths relative to bare PG, with few significant differences among cap depths. Slender wheatgrass performed best, and tufted hairgrass performed poorly. Soil caps <1 m required by regulation were sufficient for early revegetation. Soil water fluctuated more in shallow than in thick caps, and water content was generally between field capacity and wilting point regardless of cap depth. Water quality was not affected by cap depths ≤30 cm. Leachate volumes at 30 cm from distinct rainfall events were independent of precipitation amount and cap depth. The study period had lower precipitation than normal, yet soil caps were hospitable for plant growth in the first 2 yr of establishment.

  7. IAA transport in corn roots includes the root cap

    SciTech Connect

    Hasenstein, K.H. )

    1989-04-01

    In earlier reports we concluded that auxin is the growth regulator that controls gravicurvature in roots and that the redistribution of auxin occurs within the root cap. Since other reports did not detect auxin in the root cap, we attempted to confirm the IAA does move through the cap. Agar blocks containing {sup 3}H-IAA were applied to the cut surface of 5 mm long apical segments of primary roots of corn (mo17xB73). After 30 to 120 min radioactivity (RA) of the cap and root tissue was determined. While segments suspended in water-saturated air accumulated very little RA in the cap, application of 0.5 {mu}1 of dist. water to the cap (=controls) increased RA of the cap dramatically. Application to the cap of 0.5 {mu}1 of sorbitol or the Ca{sup 2+} chelator EGTA reduced cap RA to 46% and 70% respectively compared to water, without affecting uptake. Control root segments gravireacted faster than non-treated or osmoticum or EGTA treated segments. The data indicate that both the degree of hydration and calcium control the amount of auxin moving through the cap.

  8. Genetic ablation of root cap cells in Arabidopsis

    NASA Technical Reports Server (NTRS)

    Tsugeki, R.; Fedoroff, N. V.

    1999-01-01

    The root cap is increasingly appreciated as a complex and dynamic plant organ. Root caps sense and transmit environmental signals, synthesize and secrete small molecules and macromolecules, and in some species shed metabolically active cells. However, it is not known whether root caps are essential for normal shoot and root development. We report the identification of a root cap-specific promoter and describe its use to genetically ablate root caps by directing root cap-specific expression of a diphtheria toxin A-chain gene. Transgenic toxin-expressing plants are viable and have normal aerial parts but agravitropic roots, implying loss of root cap function. Several cell layers are missing from the transgenic root caps, and the remaining cells are abnormal. Although the radial organization of the roots is normal in toxin-expressing plants, the root tips have fewer cytoplasmically dense cells than do wild-type root tips, suggesting that root meristematic activity is lower in transgenic than in wild-type plants. The roots of transgenic plants have more lateral roots and these are, in turn, more highly branched than those of wild-type plants. Thus, root cap ablation alters root architecture both by inhibiting root meristematic activity and by stimulating lateral root initiation. These observations imply that the root caps contain essential components of the signaling system that determines root architecture.

  9. Quantifying Solar Wind-Polar Cap Interactions

    NASA Astrophysics Data System (ADS)

    Urban, K. D.; Gerrard, A. J.; Lanzerotti, L. J.; Weatherwax, A. T.; Huang, Y.

    2015-12-01

    It is well known that the solar wind is a major driver of ultra-low frequency [ULF] power at ground locations from low to high latitudes. However, due to the scarcity of deep polar cap magnetometer sites, it is not clear when, where, or if this is true deep inside the polar cap on open field lines where interplanetary magnetic field [IMF] ULF waves could possibly be directly detected. Given recent observations of very large Joule heating estimates from DMSP data, together with the large heating reported by the CHAMP satellite, it is important to understand the degree to which ULF waves in the solar wind can directly cause such heating. Using a time series of lagged correlation sequences ("dynamic correlograms") between GSM Bz ULF power (computed via data obtained from NASA's Advanced Composition Explorer [ACE] ahead of Earth in the solar wind) and the horizontal ULF power (H^2=N^2+E^2) from ground-based magnetometers in Earth's southern polar cap, we investigate the direct penetration of ULF waves from the solar wind into the polar ionosphere during a gamut of space weather conditions at a distributed network of Automated Geophysical Observatories [AGOs] in Antarctica. To infer causation, a predicted lag correlation maximum at each time step is computed by simply dividing the associated distance of ACE from Earth by the concurrent bulk solar wind speed. This technique helps parse out direct penetration of solar wind ULF waves from other sources (e.g., via leakage from closed field line resonances due to the bulk solar wind plasma viscously interacting at dawn/dusk flanks inducing Kelvin-Helmholtz instabilities [KHI] or compressional modes induced by impulses in solar wind dynamic pressure). The identified direct-penetrating ULF waves are related to the DMSP-derived Poynting fluxes by regression analysis, and conclusions are drawn for the importance of the ULF source for the measured heating.

  10. Underwater Christmas tree cap and lockdown apparatus

    SciTech Connect

    Best, M.J.A.

    1983-09-20

    A cap is disclosed for an underwater Christmas tree having locking probes to lock down the operating rods of a connector connecting the Christmas tree to an underwater wellhead housing. The tops of the operating rods are housed within hollow canisters at the top of the Christmas tree. The cap includes a body having circumferentially disposed locking dogs housed therein for engagement with the top of the Christmas tree. The dogs are actuated by a cam ring which telescopically receive the body and has a tapered surface for sliding over a correlatively tapered surface on each of the dogs. The body includes a metal gasket seal for sealing engagement with the top of the Christmas tree, and seals are provided between the cam ring and body. The cap has downwardly extending locking probes which extend telescopically into the canisters above the operating rods. The locking probes each include a housing and a releasable tubular piston slidably disposed in the housing. The piston is biased in a downward direction, and is held in a cocked or loaded raised position prior to release by a trigger held in engagement with the piston and housing a pin on a running tool telescopically slidably disposed in the piston. The piston is released by removal of the pin, which cams the trigger out of engagement with the housing. Upon release the piston is biased into engagement with the rod. The piston is provided with locking dogs which engage the walls of the housing and prevent upward movement of the piston and rod after release of the piston.

  11. MARK II end cap calorimeter electronics

    SciTech Connect

    Jared, R.C.; Haggerty, J.S.; Herrup, D.A.; Kirsten, F.A.; Lee, K.L.; Olson, S.R.; Wood, D.R.

    1985-10-01

    An end cap calorimeter system has been added to the MARK II detector in preparation for its use at the SLAC Linear Collider. The calorimeter uses 8744 rectangular proportional counter tubes. This paper describes the design features of the data acquisition electronics that has been installed on the calorimeter. The design and use of computer-based test stands for the amplification and signal-shaping components is also covered. A portion of the complete system has been tested in a beam at SLAC. In these initial tests, using only the calibration provided by the test stands, a resolution of 18%/..sqrt..E was achieved.

  12. Capsaicin-capped silver nanoparticles: its kinetics, characterization and biocompatibility assay

    NASA Astrophysics Data System (ADS)

    Amruthraj, Nagoth Joseph; Preetam Raj, John Poonga; Lebel, Antoine

    2015-04-01

    Capsaicin was used as a bio-reductant for the reduction of silver nitrate to form silver nanoparticles. The formation of the silver nanoparticles was initially confirmed by color change and Tyndall effect of light scattering. It was characterized with UV-visible spectroscopy, FTIR and TEM. Hemagglutination (H) test and H-inhibition assay were performed in the presence of AgNPs-capsaicin conjugates. The silver colloid solution after complete reduction turned into pale gray color. The characteristic surface plasmon resonance of silver nanoparticles (SNPs) was observed at 450 nm. Time taken for complete bio-reduction of silver nitrate and capping was found to be 16 hours. The amount of capsaicin required to reduce 20 ml of 1 mM silver nitrate solution was found to be 40 μg approximately. The FTIR results confirmed the capping of capsaicin on the silver metal. The particle size was within the range of 20-30 nm. The hemagglutination and H-inhibition test was negative for all the blood groups. The capsaicin-capped silver nanoparticles were compatible with blood cells in hemagglutination test implying biocompatibility as future therapeutic drug.

  13. On the polarization of Alpha Orionis

    NASA Technical Reports Server (NTRS)

    Doherty, L. R.

    1986-01-01

    Much of the complex behavior of the polarization observed in the M2 supergiant Alpha Ori can be explained in terms of the combined effects of Rayleigh scattering in the photosphere and scattering by circumstellar dust in the presence of one or more photospheric hot spots. The ad hoc scattering layer of electrons which Schwarz and Clarke employed in their models reported in 1984 can be avoided, eliminating the conflict with the much lower column densities found in other studies of the extended chromosphere of this star. The transfer of polarized continuum radiation in cool model atmospheres has been treated fully. Under conditions of optimal spot area and location on the disk and large temperature differences (up to 1000 K) between the spot and normal photosphere, it is possible to get a net polarization up to about 0.3 percent in the blue in the direct starlight. The effects of spot limb darkening on the polarization of scattered spot light have been evaluated. Narrow-band observations that include molecular bands are encouraged for their diagnostic value.

  14. Stable proline box motif at the N-terminal end of alpha-helices.

    PubMed Central

    Viguera, A. R.; Serrano, L.

    1999-01-01

    We describe a novel N-terminal alpha-helix local motif that involves three hydrophobic residues and a Pro residue (Pro-box motif). Database analysis shows that when Pro is the N-cap of an alpha-helix the distribution of amino acids in adjacent positions changes dramatically with respect to the average distribution in an alpha-helix, but not when Pro is at position N1. N-cap Pro residues are usually associated to Ile and Leu, at position N', Val at position N3 and a hydrophobic residue (h) at position N4. The side chain of the N-cap Pro packs against Val, while the hydrophobic residues at positions N' and N4 make favorable interactions. To analyze the role of this putative motif (sequence fingerprint hPXXhh), we have synthesized a series of peptides and analyzed them by circular dichroism (CD) and NMR. We find that this motif is formed in peptides, and that the accompanying hydrophobic interactions contribute up to 1.2 kcal/mol to helix stability. The fact that some of the residues in this fingerprint are not good N-cap and helix formers results in a small overall stabilization of the alpha-helix with respect to other peptides having Gly as the N-cap and Ala at N3 and N4. This suggests that the Pro-box motif will not specially contribute to protein stability but to the specificity of its fold. In fact, 80% of the sequences that contain the fingerprint sequence in the protein database are adopting the described structural motif, and in none of them is the helix extended to place Pro at the more favorable N1 position. PMID:10493574

  15. THE LINE POLARIZATION WITHIN A GIANT Ly{alpha} NEBULA

    SciTech Connect

    Prescott, Moire K. M.; Smith, Paul S.; Schmidt, Gary D.; Dey, Arjun

    2011-04-01

    Recent theoretical work has suggested that Ly{alpha} nebulae could be substantially polarized in the Ly{alpha} emission line, depending on the geometry, kinematics, and powering mechanism at work. Polarization observations can therefore provide a useful constraint on the source of ionization in these systems. In this Letter, we present the first Ly{alpha} polarization measurements for a giant Ly{alpha} nebula at z{approx} 2.656. We do not detect any significant linear polarization of the Ly{alpha} emission: P{sub Ly{alpha}} = 2.6% {+-} 2.8% (corrected for statistical bias) within a single large aperture. The current data also do not show evidence for the radial polarization gradient predicted by some theoretical models. These results rule out singly scattered Ly{alpha} (e.g., from the nearby active galactic nucleus, AGN) and may be inconsistent with some models of backscattering in a spherical outflow. However, the effects of seeing, diminished signal-to-noise ratio, and angle averaging within radial bins make it difficult to put strong constraints on the radial polarization profile. The current constraints may be consistent with higher density outflow models, spherically symmetric infall models, photoionization by star formation within the nebula or the nearby AGN, resonant scattering, or non-spherically symmetric cold accretion (i.e., along filaments). Higher signal-to-noise ratio data probing to higher spatial resolution will allow us to harness the full diagnostic power of polarization observations in distinguishing between theoretical models of giant Ly{alpha} nebulae.

  16. Rainbow Scattering by a Coated Sphere

    NASA Technical Reports Server (NTRS)

    Lock, James A.; Jamison, J. Michael; Lin, Chih-Yang

    1994-01-01

    We examine the behavior of the first-order rainbow for a coated sphere by using both ray theory and Aden-Kerker wave theory as the radius of the core alpha(sub 12) and the thickness of the coating beta are varied. As the ratio beta/alpha(sub 12) increases from 10(sup -4) to 0.33, we find three classes of rainbow phenomena that cannot occur for a homogeneous-sphere rainbow. For beta/alpha(sub 12) approx less than 10(sup -3), the rainbow intensity is an oscillatory function of the coating thickness, for beta/alpha(sub 12) approx. 10(sup -2), the first-order rainbow breaks into a pair of twin rainbows, and for beta/alpha(sub 12) approx. 0.33, various rainbow-extinction transitions occur. Each of these effects is analyzed, and their physical interpretations are given. A Debye series decomposition of coated-sphere partial-wave scattering amplitudes is also performed and aids in the analysis.

  17. Incorporating Wind Generation in Cap and Trade Programs

    SciTech Connect

    Bluestein, J.; Salerno, E.; Bird, L.; Vimmerstedt, L.

    2006-07-01

    Cap and trade programs are increasingly being used to reduce emissions from electricity generation in the United States. Cap and trade programs primarily target emitting generators, but programs have also included renewable generators, such as wind generators. States cite several reasons why they have considered the policy option of including renewable generators in cap and trade programs: to provide an incentive for lower-emitting generation, to achieve emissions reductions in non-capped pollutants, and to gain local economic benefits associated with renewable energy projects. The U.S. Environmental Protection Agency also notes these rationales for considering this policy alternative, and the National Association of Regulatory Commissioners (NARUC) passed a resolution supporting the inclusion of renewable energy in cap and trade programs. This report explores why states consider this policy option, what participation could mean for wind generators, and how wind generation can most effectively be included in state, federal, and regional cap and trade programs.

  18. Magnetically capped rolled-up nanomembranes.

    PubMed

    Streubel, Robert; Thurmer, Dominic J; Makarov, Denys; Kronast, Florian; Kosub, Tobias; Kravchuk, Volodymyr; Sheka, Denis D; Gaididei, Yuri; Schäfer, Rudolf; Schmidt, Oliver G

    2012-08-01

    Modifying the curvature in magnetic nanostructures is a novel and elegant way toward tailoring physical phenomena at the nanoscale, allowing one to overcome limitations apparent in planar counterparts. Here, we address curvature-driven changes of static magnetic properties in cylindrically curved magnetic segments with different radii of curvature. The curved architectures are prepared by capping nonmagnetic micrometer- and nanometer-sized rolled-up membranes with a soft-magnetic 20 nm thick permalloy (Ni(80)Fe(20)) film. A quantitative comparison between the magnetization reversal processes in caps with different diameters is given. The phase diagrams of magnetic equilibrium domain patterns (diameter versus length) are generated. For this, joint experimental, including X-ray magnetic circular dichroism photoelectron emission microscopy (XMCD-PEEM), and theoretical studies are carried out. The anisotropic magnetostatic interaction in cylindrically curved architectures originating from the thickness gradient reduces substantially the magnetostatic interaction between closely packed curved nanowires. This feature is beneficial for racetrack memory devices, since a much higher areal density might be achieved than possible with planar counterparts.

  19. Comparison of Polar Cap (PC) index calculations.

    NASA Astrophysics Data System (ADS)

    Stauning, P.

    2012-04-01

    The Polar Cap (PC) index introduced by Troshichev and Andrezen (1985) is derived from polar magnetic variations and is mainly a measure of the intensity of the transpolar ionospheric currents. These currents relate to the polar cap antisunward ionospheric plasma convection driven by the dawn-dusk electric field, which in turn is generated by the interaction of the solar wind with the Earth's magnetosphere. Coefficients to calculate PCN and PCS index values from polar magnetic variations recorded at Thule and Vostok, respectively, have been derived by several different procedures in the past. The first published set of coefficients for Thule was derived by Vennerstrøm, 1991 and is still in use for calculations of PCN index values by DTU Space. Errors in the program used to calculate index values were corrected in 1999 and again in 2001. In 2005 DMI adopted a unified procedure proposed by Troshichev for calculations of the PCN index. Thus there exists 4 different series of PCN index values. Similarly, at AARI three different sets of coefficients have been used to calculate PCS indices in the past. The presentation discusses the principal differences between the various PC index procedures and provides comparisons between index values derived from the same magnetic data sets using the different procedures. Examples from published papers are examined to illustrate the differences.

  20. Backward pion-nucleon scattering

    SciTech Connect

    F. Huang; Sibirtsev, Alex; Haidenbauer, Johann; Meissner, Ulf-G.

    2010-02-01

    A global analysis of the world data on differential cross sections and polarization asymmetries of backward pion-nucleon scattering for invariant collision energies above 3 GeV is performed in a Regge model. Including the $N_\\alpha$, $N_\\gamma$, $\\Delta_\\delta$ and $\\Delta_\\beta$ trajectories, we reproduce both angular distributions and polarization data for small values of the Mandelstam variable $u$, in contrast to previous analyses. The model amplitude is used to obtain evidence for baryon resonances with mass below 3 GeV. Our analysis suggests a $G_{39}$ resonance with a mass of 2.83 GeV as member of the $\\Delta_{\\beta}$ trajectory from the corresponding Chew-Frautschi plot.

  1. Acoustic Monitoring of the Arctic Ice Cap

    NASA Astrophysics Data System (ADS)

    Porter, D. L.; Goemmer, S. A.; Chayes, D. N.

    2012-12-01

    Introduction The monitoring of the Arctic Ice Cap is important economically, tactically, and strategically. In the scenario of ice cap retreat, new paths of commerce open, e.g. waterways from Northern Europe to the Far East. Where ship-going commerce is conducted, the U.S. Navy and U.S. Coast Guard have always stood guard and been prepared to assist from acts of nature and of man. It is imperative that in addition to measuring the ice from satellites, e.g. Icesat, that we have an ability to measure the ice extent, its thickness, and roughness. These parameters play an important part in the modeling of the ice and the processes that control its growth or shrinking and its thickness. The proposed system consists of three subsystems. The first subsystem is an acoustic source, the second is an array of geophones and the third is a system to supply energy and transmit the results back to the analysis laboratory. The subsystems are described below. We conclude with a plan on how to tackle this project and the payoff to the ice cap modeler and hence the users, i.e. commerce and defense. System Two historically tested methods to generate a large amplitude multi-frequency sound source include explosives and air guns. A new method developed and tested by the University of Texas, ARL is a combustive Sound Source [Wilson, et al., 1995]. The combustive sound source is a submerged combustion chamber that is filled with the byproducts of the electrolysis of sea water, i.e. Hydrogen and Oxygen, an explosive mixture which is ignited via a spark. Thus, no additional compressors, gases, or explosives need to be transported to the Arctic to generate an acoustic pulse capable of the sediment and the ice. The second subsystem would be geophones capable of listening in the O(10 Hz) range and transmitting that data back to the laboratory. Thus two single arrays of geophones arranged orthogonal to each other with a range of 1000's of kilometers and a combustive sound source where the two

  2. Microfine toe caps: an innovative and cost-saving solution.

    PubMed

    Elwell, Rebecca; Wigg, Jane

    2015-04-01

    This article discusses the use of Microfine toe caps (Haddenham, UK) for the treatment of digit swelling. It will discuss the indications and contraindications of the device and offers some case studies where toe caps have been used in clinical practice. The use of the Microfine toe cap offers an alternative to toe bandaging, has many different applications and can be safe and time-saving to apply when used appropriately following a full and holistic assessment.

  3. Capped bit patterned media for high density magnetic recording

    NASA Astrophysics Data System (ADS)

    Li, Shaojing; Livshitz, Boris; Bertram, H. Neal; Inomata, Akihiro; Fullerton, Eric E.; Lomakin, Vitaliy

    2009-04-01

    A capped composite patterned medium design is described which comprises an array of hard elements exchange coupled to a continuous cap layer. The role of the cap layer is to lower the write field of the individual hard element and introduce ferromagnetic exchange interactions between hard elements to compensate the magnetostatic interactions. Modeling results show significant reduction in the reversal field distributions caused by the magnetization states in the array which is important to prevent bit errors and increase achievable recording densities.

  4. Preform spar cap for a wind turbine rotor blade

    DOEpatents

    Livingston, Jamie T.; Driver, Howard D.; van Breugel, Sjef; Jenkins, Thomas B.; Bakhuis, Jan Willem; Billen, Andrew J.; Riahi, Amir

    2011-07-12

    A spar cap for a wind turbine rotor blade. The spar cap may include multiple preform components. The multiple preform components may be planar sheets having a swept shape with a first end and a second end. The multiple preform components may be joined by mating the first end of a first preform component to the second end of a next preform component, forming the spar cap.

  5. Alpha/sub 1/ receptor coupling events initiated by methoxy-substituted tolazoline partial agonists

    SciTech Connect

    Wick, P.; Keung, A.; Deth, R.

    1986-03-01

    A series of mono- and dimethyoxy substituted tolazoline derivatives, known to be partial agonists at the alpha/sub 1/ receptor, were compared with the ..cap alpha../sub 1/ selective full agonist phenylephrine (PE) on isolated strips of rabbit aorta Agonist activity was evaluated in contraction, /sup 45/Ca influx, /sup 45/Ca efflux, and /sup 32/P-Phospholipid labelling studies. Maximum contractile responses for the 2-, 3-, and 3, 5- methoxy substituted tolazoline derivatives (10/sup -5/M) were 53.8, 67.6 and 99.7% of the PE (10/sup -5/M) response respectively. These same partial agonists caused a stimulation of /sup 45/Ca influx to the extent of 64, 86, and 95% of the PE response respectively. In /sup 45/Ca efflux studies, (a measure of the intracellular Ca/sup +2/ release) the tolazolines caused: 30%, 63%, and 78% of the PE stimulated level. /sup 32/P-Phosphatidic acid (PA) labelling was measured as an index of PI turnover after ..cap alpha../sub 1/ receptor stimulation. Compared to PE, the 2-, 3-, and 3,5- methoxy substituted tolazoline derivatives caused 22, 46, and 72% PA labelling. The above values are all in reasonable accord with the rank order or agonist activity shown in maximum contractile responses. The results of this investigation suggest that partial agonists stimulate ..cap alpha.. receptor coupling events at a level which is quantitatively comparable to their potencies in causing contraction of arterial smooth muscle.

  6. ALPHA MIS: Reference manual

    SciTech Connect

    Lovin, J.K.; Haese, R.L.; Heatherly, R.D.; Hughes, S.E.; Ishee, J.S.; Pratt, S.M.; Smith, D.W.

    1992-02-01

    ALPHA is a powerful and versatile management information system (MIS) initiated and sponsored and by the Finance and Business Management Division of Oak Ridge National Laboratory, who maintain and develop it in concert with the Business Systems Division for its Information Center. A general-purpose MIS, ALPHA allows users to access System 1022 and System 1032 databases to obtain and manage information. From a personal computer or a data terminal, Energy Systems employees can use ALPHA to control their own report reprocessing. Using four general commands (Database, Select, Sort, and Report) they can (1) choose a mainframe database, (2) define subsets within it, (3) sequentially order a subset by one or more variables, and (4) generate a report with their own or a canned format.

  7. Preparation and Properties of Nanoparticles of Calcium Phosphates With Various Ca/P Ratios.

    PubMed

    Sun, Limin; Chow, Laurence C; Frukhtbeyn, Stanislav A; Bonevich, John E

    2010-01-01

    This study aimed at preparing and studying the properties of nanoparticles of calcium phosphate (nCaP) with Ca/P ratios ranging from 1.0 to 1.67 using a spray-drying technique. Micro-structural analyses suggested that the nCaPs with Ca/P ratios of 1.67 to 1.33 were nano-sized amorphous calcium phosphate (ACP) containing varying amounts of acid phosphate and carbonate. The nCaP with Ca/P ratio of 1 contained only nano-sized low crystalline dicalcium phosphate (DCP). BET measurements of the nCaPs showed specific surface areas of (12 ± 2 to 50 ± 1) m(2)/g, corresponding to estimated equivalent spherical diameters of (38 to 172) nm. However, dynamic light scattering measurements revealed much larger particles of (380 ± 49 to 768 ± 111) nm, owing to agglomeration of the smaller primary nano particles as revealed by Scanning Electron Microscopy (SEM). Thermodynamic solubility measurements showed that the nCaPs with Ca/P ratio of 1.33 - 1.67 all have similar solubility behavior. The materials were more soluble than the crystalline hydroxyapatite (HA) at pH greater than about 4.7, and more soluble than β-tricalcium phosphate (β-TCP), octacalcium phosphate (OCP) and DCP at pH above 5.5. Their solubility approached that of α-tricalcium phosphate (α-TCP) at about pH 7. These nCaPs, which cannot be readily prepared by other currently available methods for nanoparticle preparation, have potential biomedical applications.

  8. Preparation and Properties of Nanoparticles of Calcium Phosphates With Various Ca/P Ratios

    PubMed Central

    Sun, Limin; Chow, Laurence C.; Frukhtbeyn, Stanislav A.; Bonevich, John E.

    2010-01-01

    This study aimed at preparing and studying the properties of nanoparticles of calcium phosphate (nCaP) with Ca/P ratios ranging from 1.0 to 1.67 using a spray-drying technique. Micro-structural analyses suggested that the nCaPs with Ca/P ratios of 1.67 to 1.33 were nano-sized amorphous calcium phosphate (ACP) containing varying amounts of acid phosphate and carbonate. The nCaP with Ca/P ratio of 1 contained only nano-sized low crystalline dicalcium phosphate (DCP). BET measurements of the nCaPs showed specific surface areas of (12 ± 2 to 50 ± 1) m2/g, corresponding to estimated equivalent spherical diameters of (38 to 172) nm. However, dynamic light scattering measurements revealed much larger particles of (380 ± 49 to 768 ± 111) nm, owing to agglomeration of the smaller primary nano particles as revealed by Scanning Electron Microscopy (SEM). Thermodynamic solubility measurements showed that the nCaPs with Ca/P ratio of 1.33 – 1.67 all have similar solubility behavior. The materials were more soluble than the crystalline hydroxyapatite (HA) at pH greater than about 4.7, and more soluble than β-tricalcium phosphate (β-TCP), octacalcium phosphate (OCP) and DCP at pH above 5.5. Their solubility approached that of α-tricalcium phosphate (α-TCP) at about pH 7. These nCaPs, which cannot be readily prepared by other currently available methods for nanoparticle preparation, have potential biomedical applications. PMID:21037948

  9. Ultrasensitive optical detection of trinitrotoluene by ethylenediamine-capped gold nanoparticles.

    PubMed

    Lin, Dongyue; Liu, Honglin; Qian, Kai; Zhou, Xia; Yang, Liangbao; Liu, Jinhuai

    2012-09-26

    This study found that 1,2-ethylenediamine (EDA) as a primary amine could be modified onto the surface of citrate-stabilized gold nanoparticles (Au NPs), and the EDA-capped Au NPs were successfully used as an ultrasensitive optical probe for TNT detection. The strong donor-acceptor (D-A) interactions between EDA and trinitrotoluene (TNT) at the Au NP/solution interface induced significant aggregation of the EDA-capped Au NPs, and enabled to easily realize the direct colorimetric detection of ultratrace TNT. The results showed that such a color change was readily seen by the naked eye, and the colorimetric detection could be down to 400 pM level of TNT with excellent discrimination against other nitro compounds. UV-vis absorption spectroscopy was used to examine the TNT-induced changes in local surface plasmon resonance (LSPR) of EDA-capped Au NPs, and a new LSPR band at ca. 630 nm arose along with the addition of TNT, which produced a detection limit of TNT down to ca. 40 pM. Furthermore, dynamic light scattering measurements evidenced the ultratrace TNT-induced small changes in the size of the EDA-capped Au NPs, and realized the quick and accurate detection of TNT in 0.4 pM level. These results demonstrated the ultrahigh sensitivity of this optical probe for TNT detection. Moreover, this optical probe is sample, stable, low-cost, and these excellent properties make it quite promising for infield and rapid detection of TNT.

  10. Trap door and underside of cap stone of pyramid ion ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Trap door and underside of cap stone of pyramid ion - Washington Monument, High ground West of Fifteenth Street, Northwest, between Independence & Constitution Avenues, Washington, District of Columbia, DC

  11. Design and Performance of Capping Layers for EUV Multilayer Mirrors

    SciTech Connect

    Bajt, S; Chapman, H N; Nuygen, N; Alameda, J; Robinson, J C; Malinowski, M; Gullikson, E; Aquila, A; Tarrio, C; Grantham, S

    2003-03-10

    The reflectance stability of multilayer coatings for extreme ultraviolet lithography (EUVL) in a commercial tool environment is of uttermost importance to ensure continuous exposures with minimum maintenance cost. We have made substantial progress in designing the protective capping layer coatings, understanding their performance and estimating their lifetimes based on accelerated electron beam and EUV exposure studies. Our current capping layer coatings have about 40 times longer lifetimes than Si-capped multilayer optics. Nevertheless, the lifetime of current Ru-capped multilayers is too short to satisfy commercial tool requirements and further improvements are essential.

  12. The size of the EB cap determines instantaneous microtubule stability

    PubMed Central

    Duellberg, Christian; Cade, Nicholas I; Holmes, David; Surrey, Thomas

    2016-01-01

    The function of microtubules relies on their ability to switch between phases of growth and shrinkage. A nucleotide-dependent stabilising cap at microtubule ends is thought to be lost before this switch can occur; however, the nature and size of this protective cap are unknown. Using a microfluidics-assisted multi-colour TIRF microscopy assay with close-to-nm and sub-second precision, we measured the sizes of the stabilizing cap of individual microtubules. We find that the protective caps are formed by the extended binding regions of EB proteins. Cap lengths vary considerably and longer caps are more stable. Nevertheless, the trigger of instability lies in a short region at the end of the cap, as a quantitative model of cap stability demonstrates. Our study establishes the spatial and kinetic characteristics of the protective cap and provides an insight into the molecular mechanism by which its loss leads to the switch from microtubule growth to shrinkage. DOI: http://dx.doi.org/10.7554/eLife.13470.001 PMID:27050486

  13. Generalized method for constructing the atomic coordinates of nanotube caps

    NASA Astrophysics Data System (ADS)

    Robinson, M.; Suarez-Martinez, I.; Marks, N. A.

    2013-04-01

    A practical numerical method for the rapid construction of nanotube caps is proposed. Founded upon the notion of lattice duality, the algorithm considers the face dual representation of a given nanotube which is used to solve an energy minimization problem analogous to The Thomson Problem. Not only does this produce caps for nanotubes of arbitrary chirality, but the caps generated will be physically sensible and in most cases the lowest energy structure. To demonstrate the applicability of the technique, caps of the (5,5) and the (10,0) nanotubes are investigated by means of density-functional tight binding (DFTB). The calculation of cap energies highlights the ability of the algorithm to produce lowest energy caps. Due to the preferential construction of spherical caps, the technique is particularly well suited for the construction of capped multiwall nanotubes (MWNTs). To validate this proposal and the overall robustness of the algorithm, a MWNT is constructed containing the chiralities (9,2)@(15,6)@(16,16). The algorithm presented paves the way for future computational investigations into the physics and chemistry of capped nanotubes.

  14. Intercomparison Study of the CAPS PMex (Cavity Attenuated Phase Shift Particle Light Extinction Monitor) with the combination of an Integrating Nephelometer and a Particle Soot Absorption Photometer

    NASA Astrophysics Data System (ADS)

    Petzold, A.; Onasch, T.; Kebabian, P.; Freedman, A.

    2012-10-01

    An evaluation of the Cavity Attenuated Phase Shift particle light extinction monitor (CAPS PMex) by means of a combination of a 3-wavelength Integrating Nephelometer (NEPH; TSI Model 3563) and a 3-wavelength filter-based Particle Soot Absorption Photometer (PSAP) was carried out using both laboratory generated test particles and ambient aerosols. An accurate determination of a fixed pathlength correction for the CAPS PMex was made by comparing extinction measurements using polystyrene latex (PSL) spheres in combination with Mie scattering calculations to account for the presence of PSL conglomerates. These studies yielded a linear instrument response over the investigated dynamical range from 20 to 450 M m-1 (10-6 m-1) with a linear correlation coefficient of R2 > 0.98. The adjustment factor was determined to be 1.05 times that previously reported. Correlating CAPS extinction to extinction measured by the NEPH-PSAP combination using laboratory-generated polydisperse mixtures of purely scattering ammonium sulfate and highly absorbing black carbon provided a linear regression line with slope m = 0.99 (R2 = 0.996) for single-scattering albedo values (λ = 630 nm) ranging from 0.35 (black carbon) to 1.00 (ammonium sulfate). For ambient aerosol, light extinction measured by CAPS PMex was highly correlated (R2 = 0.995) to extinction measured by the NEPH-PSAP combination with slope m = 0.95.

  15. Intercomparison of a Cavity Attenuated Phase Shift-based extinction monitor (CAPS PMex) with an integrating nephelometer and a filter-based absorption monitor

    NASA Astrophysics Data System (ADS)

    Petzold, A.; Onasch, T.; Kebabian, P.; Freedman, A.

    2013-05-01

    An evaluation of the Cavity Attenuated Phase Shift particle light extinction monitor (CAPS PMex) using a combination of a 3-wavelength Integrating Nephelometer (NEPH) and a 3-wavelength filter-based Particle Soot Absorption Photometer (PSAP) was carried out using both laboratory-generated test particles and ambient aerosols. An accurate determination of a fixed pathlength correction for the CAPS PMex was made by comparing extinction measurements using monodisperse PSL spheres in combination with Mie scattering calculations to account for the presence of PSL conglomerates. These studies yielded a linear instrument response over the investigated dynamical range from 20 to 450 Mm-1 (10-6 m-1) with a linear correlation coefficient of R2 > 0.98. The adjustment factor was determined to be 1.05 times that previously reported. Correlating CAPS extinction to extinction measured by the NEPH + PSAP combination using laboratory-generated polydisperse mixtures of purely scattering ammonium sulfate and highly absorbing black carbon provided a linear regression line with slope m = 1.00 (R2 = 0.994) for single-scattering albedo values (λ = 630 nm) ranging from 0.35 (black carbon) to 1.00 (ammonium sulfate). For ambient aerosol, light extinction measured by CAPS was highly correlated (R2 = 0.995) to extinction measured by the NEPH + PSAP combination with slope m = 0.95.

  16. Portable alpha spectrometer.

    PubMed

    Martín Sánchez, A; de la Torre Pérez, J

    2012-09-01

    Many portable devices have been designed to detect γ-rays or alpha and beta particles. Most of the α-particle detectors give the total count as a result, without identifying the radionuclides existing in the sample. The development of a device allowing rapid and straightforward α-particle spectrometry would be very useful for detecting the radioactive contents of unknown samples. This work describes the construction of a portable device using silicon semiconductor detectors designed to rapidly detect and possibly identify alpha-emitting radionuclides.

  17. The Apollo Alpha Spectrometer.

    NASA Technical Reports Server (NTRS)

    Jagoda, N.; Kubierschky, K.; Frank, R.; Carroll, J.

    1973-01-01

    Located in the Science Instrument Module of Apollo 15 and 16, the Alpha Particle Spectrometer was designed to detect and measure the energy of alpha particles emitted by the radon isotopes and their daughter products. The spectrometer sensor consisted of an array of totally depleted silicon surface barrier detectors. Biased amplifier and linear gate techniques were utilized to reduce resolution degradation, thereby permitting the use of a single 512 channel PHA. Sensor identification and in-flight radioactive calibration were incorporated to enhance data reduction.

  18. Measurements of the spin-correlation parameters A/sub 00k/k, A/sub 00k/s, and A/sub 00s/s in p-p elastic scattering between 400 and 600 MeV

    SciTech Connect

    Aprile, E.; Hausammann, R.; Heer, E.; Hess, R.; Lechanoine-Leluc, C.; Leo, W.R.; Morenzoni, S.; Onel, Y.; Rapin, D.; Mango, S.

    1983-07-01

    We have measured the spin-correlation parameters A/sub 00k/k, A/sub 00k/s, and A/sub 00s/s in p-p scattering between 400 and 600 MeV using a longitudinally polarized beam and a butanol target polarized in the horizontal plane. Owing to the restrictive geometrical acceptance of the target, the polarization axis of the target was oriented at an angle ..cap alpha.. with respect to beam direction. The parameters A/sub 00k/k and A/sub 00k/s were therefore measured as a linear combination at 577, 536, 514, 494, and 445 MeV. These experiments were extended to the measurement of A/sub 00k/s and A/sub 00s/s by using a transversely polarized beam. We present the results, which are compared with phase-shift predictions.

  19. Scattering from binary optics

    NASA Technical Reports Server (NTRS)

    Ricks, Douglas W.

    1993-01-01

    There are a number of sources of scattering in binary optics: etch depth errors, line edge errors, quantization errors, roughness, and the binary approximation to the ideal surface. These sources of scattering can be systematic (deterministic) or random. In this paper, scattering formulas for both systematic and random errors are derived using Fourier optics. These formulas can be used to explain the results of scattering measurements and computer simulations.

  20. Approximations for photoelectron scattering

    NASA Astrophysics Data System (ADS)

    Fritzsche, V.

    1989-04-01

    The errors of several approximations in the theoretical approach of photoelectron scattering are systematically studied, in tungsten, for electron energies ranging from 10 to 1000 eV. The large inaccuracies of the plane-wave approximation (PWA) are substantially reduced by means of effective scattering amplitudes in the modified small-scattering-centre approximation (MSSCA). The reduced angular momentum expansion (RAME) is so accurate that it allows reliable calculations of multiple-scattering contributions for all the energies considered.

  1. Inclusive inelastic scattering of heavy ions and nuclear correlations

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Townsend, Lawrence W.; Wilson, John W.; Khandelwal, Govind S.

    1990-01-01

    Calculations of inclusive inelastic scattering distributions for heavy ion collisions are considered within the high energy optical model. Using ground state sum rules, the inclusive projectile and complete projectile-target inelastic angular distributions are treated in both independent particle and correlated nuclear models. Comparisons between the models introduced are made for alpha particles colliding with He-4, C-12, and O-16 targets and protons colliding with O-16. Results indicate that correlations contribute significantly, at small momentum transfers, to the inelastic sum. Correlation effects are hidden, however, when total scattering distributions are considered because of the dominance of elastic scattering at small momentum transfers.

  2. Impact of B4C capping layer for EUV mask on the sensitivity of patterned mask inspection using projection electron microscope

    NASA Astrophysics Data System (ADS)

    Iida, Susumu; Hirano, Ryoichi; Amano, Tsuyoshi; Watanabe, Hidehiro

    2014-10-01

    The inspection sensitivity of a patterned extreme ultraviolet (EUV) mask with B4C capped multilayer (ML) was investigated using a simulated projection electron microscope (PEM) image. Extrusion and intrusion defects with 16 nm in size were detected with their intensity of > 10 times the standard deviation of the background level on a half-pitch (hp) 64 nm line and space pattern. The defect detection sensitivity in this case was higher than that of Ru capped ML sample, and has a potential to meet the requirement for beyond 16 nm node generation from the standpoint of patterned mask inspection using the PEM technique. These results indicate that B4C capping layer besides its good durability has an advantage for high sensitivity of patterned mask inspection. The optimal condition of the incident beam energy was found to be 500 and 1000 eV for the samples of B4C capped ML and B4C buffered Ru capped ML, respectively. The sensitivity of defect detection was strongly affected by the difference of secondary electron emission coefficients (SEECs) between the absorber layer and capping layer. However, severely scattered electrons near the pattern edge become a source of noise and then they block the effect of large SEEC difference. Thus, the small incident beam energy was found to be preferable when the SEEC difference was relatively high.

  3. Actin filament barbed-end capping activity in neutrophil lysates: the role of capping protein-beta 2.

    PubMed

    DiNubile, M J; Cassimeris, L; Joyce, M; Zigmond, S H

    1995-12-01

    A barbed-end capping activity was found in high speed supernates of neutrophils lysed in submicromolar calcium. In dilute supernate (> or = 100-fold dilution of cytoplasm), this activity accounted for most of the inhibition of barbed-end elongation of pyrenyl-G-actin from spectrin-F-actin seeds. Pointed-end elongation from gelsolin-capped F-actin seeds was not inhibited at comparable concentrations of supernate, thus excluding actin monomer sequestration as a cause of the observed inhibition. Most of the capping activity was due to capping protein-beta 2 (a homologue of cap Z). Thus, while immunoadsorption of > or = 95% of the gelsolin in the supernate did not decrease capping activity, immunoadsorption of capping protein-beta 2 reduced capping activity proportionally to the amount of capping protein-beta 2 adsorbed. Depletion of > 90% of capping protein-beta 2 from the supernate removed 90% of its capping activity. The functional properties of the capping activity were defined. The dissociation constant for binding to barbed ends (determined by steady state and kinetic analyses) was approximately 1-2 nM; the on-rate of capping was between 7 x 10(5) and 5 x 10(6) M-1 s-1; and the off-rate was approximately 2 x 10(-3) s-1. The concentration of capper free in the intact cell (determined by adsorption of supernate with spectrin-actin seeds) was estimated to be approximately 1-2 microM. Thus, there appeared to be enough high affinity capper to cap all the barbed ends in vivo. Nevertheless, immediately after lysis with detergent, neutrophils contained sites that nucleate barbed-end elongation of pyrenyl-G-actin. These barbed ends subsequently become capped with a time course and concentration dependence similar to that of spectrin-F-actin seeds in high speed supernates. These observations suggest that, despite the excess of high affinity capper, some ends either are not capped in vivo or are transiently uncapped upon lysis and dilution. PMID:8590796

  4. Alpha-Decay Half-Lives of Superheavy Nuclei

    SciTech Connect

    Budaca, A. I.; Silisteanu, I.; Silisteanu, A. O.; Anghel, C. I.

    2010-11-24

    Half-lives given by self-consistent models for the {alpha}-clustering and resonance scattering are calculated and compared with data and empirical estimates. The major influence of the pairing, deformed shell closures and screening corrections is evidenced in the systematics of half-lives and provides a convenient basis for the interpretation of observed trends of the data and for prediction of new results. The very small widths of {alpha}-resonances observed experimentally in fusion-evaporation reactions, are interpreted as resonance levels of radioactive products, and such a correlation contributes directly to the study of the nuclear structure on the basis of decay data.

  5. Interannual variability of Mars' south polar CAP

    NASA Astrophysics Data System (ADS)

    James, P. B.; Malolepszy, K. M.; Martin, L. J.

    1987-08-01

    Published observational data on the seasonal recession of the south polar cap on Mars (covering the period 1903-1977) are compiled in tables and graphs and analyzed statistically. The basic data set (photographic observations obtained at Lowell Observatory) of Fischbacher et al. (1960) and James and Lumme (1982) and the reduction procedures described by Baum and Martin (1973) are employed, and Viking data from 1977 are used for comparison; the early onset (relative to the mean) of the 1956 recession is characterized in detail. A list of photographically documented large dust storms is provided, and it is suggested that in years with early spring storms, recession may be slower than in years without such storms.

  6. Optimized capping layers for EUV multilayers

    DOEpatents

    Bajt, Sasa; Folta, James A.; Spiller, Eberhard A.

    2004-08-24

    A new capping multilayer structure for EUV-reflective Mo/Si multilayers consists of two layers: A top layer that protects the multilayer structure from the environment and a bottom layer that acts as a diffusion barrier between the top layer and the structure beneath. One embodiment combines a first layer of Ru with a second layer of B.sub.4 C. Another embodiment combines a first layer of Ru with a second layer of Mo. These embodiments have the additional advantage that the reflectivity is also enhanced. Ru has the best oxidation resistance of all materials investigated so far. B.sub.4 C is an excellent barrier against silicide formation while the silicide layer formed at the Si boundary is well controlled.

  7. Glass microstructure capping and bonding techniques.

    PubMed

    Mazurczyk, Radoslaw; Mansfield, Colin D; Lygan, Marcin

    2013-01-01

    The capping of microfluidic features fabricated in glass substrates is achievable by various technological methods. Of the entire spectrum of possibilities (gluing, glass bonding via intermediate layers, pressure or plasma-assisted glass bonding, etc.) a detailed description of three techniques is presented here. The first is a low temperature PDMS-glass adhesion bonding, the second is medium temperature pressure assisted glass-glass bonding, and finally, high temperature glass-glass fusion bonding. All these protocols allow completion of the manufacturing process for a fully enclosed microfluidic chip. Nevertheless, as they are complementary rather than competing methods, they effectively extend the range of tools available to fabricate lab-on-a-chip microdevices. Each has its own merits and each could feasibly be used at different developmental stages of a given microfluidic device.

  8. Glaciers and ice caps outside Greenland

    USGS Publications Warehouse

    Sharp, Marin; Wolken, G.; Burgess, D.; Cogley, J.G.; Copland, L.; Thomson, L.; Arendt, A.; Wouters, B.; Kohler, J.; Andreassen, L.M.; O'Neel, Shad; Pelto, M.

    2015-01-01

    Mountain glaciers and ice caps cover an area of over 400 000 km2 in the Arctic, and are a major influence on global sea level (Gardner et al. 2011, 2013; Jacob et al. 2012). They gain mass by snow accumulation and lose mass by meltwater runoff. Where they terminate in water (ocean or lake), they also lose mass by iceberg calving. The climatic mass balance (Bclim, the difference between annual snow accumulation and annual meltwater runoff) is a widely used index of how glaciers respond to climate variability and change. The total mass balance (ΔM) is defined as the difference between annual snow accumulation and annual mass losses (by iceberg calving plus runoff).

  9. [alpha]-Oxocarboxylic Acids

    ERIC Educational Resources Information Center

    Kerber, Robert C.; Fernando, Marian S.

    2010-01-01

    Several [alpha]-oxocarboxylic acids play key roles in metabolism in plants and animals. However, there are inconsistencies between the structures as commonly portrayed and the reported acid ionization constants, which result because the acids are predominantly hydrated in aqueous solution; that is, the predominant form is RC(OH)[subscript 2]COOH…

  10. From Alpha to Omega

    ERIC Educational Resources Information Center

    Czaja, Paul Clement

    2006-01-01

    The Alpha point of the authors' life as a Montessori educator began in 1959, when he was a graduate student studying philosophy at Fordham University in the Bronx, New York. While studying the works of the great American philosopher William James, the author came across the writings of Maria Montessori and immediately became captivated by her…

  11. Scattering in optical materials

    SciTech Connect

    Musikant, S.

    1983-01-01

    Topics discussed include internal scattering and surface scattering, environmental effects, and various applications. Papers are presented on scattering in ZnSe laser windows, the far-infrared reflectance spectra of optical black coatings, the effects of standard optical shop practices on scattering, and the damage susceptibility of ring laser gyro class optics. Attention is also given to the infrared laser stimulated desorption of pyridine from silver surfaces, to electrically conductive black optical paint, to light scattering from an interface bubble, and to the role of diagnostic testing in identifying and resolving dimensional stability problems in electroplated laser mirrors.

  12. Lyman-Alpha aurora

    SciTech Connect

    Durrance, S.T.; Clarke, J.T.

    1984-10-01

    The existence of intense and variable H Ly a emission from Uranus is demonstrated utilizing the monochromatic imaging capabilities of the International Ultraviolet Explorer satellite. A series of 14 observations, using the IUE short wavelength spectrograph in low dispersion and covering the period from 3 March 1982 through 2 September 1983, shows the disk averaged Ly a brightness of Uranus to vary between 690 and 2230 Rayleighs. Model calculations indicates that 400 R of this emission can be attributed to resonant scattering of solar Ly a radiation. An upper limit of 100 R is obtained for the Raman scattering of solar Ly a by H2 (1280 A). This implies that 300 R is contributed to the planetary Ly a emission by Rayleigh scattering. In addition to being unexpectedly strong, the Uranian Ly a emission has been observed to vary by a factor of two in one 24 hr period and by about 50% in one 5 hr period.

  13. ASYMMETRIC ABSORPTION PROFILES OF Ly{alpha} AND Ly{beta} IN DAMPED Ly{alpha} SYSTEMS

    SciTech Connect

    Lee, Hee-Won

    2013-08-01

    Damped Ly{alpha} systems observed in the quasar spectra are characterized by a high neutral hydrogen column density, N{sub HI} > 2 x 10{sup 20} cm{sup -2}. The absorption wing profiles are often fitted using the Voigt function due to the fact that the scattering cross section near the resonant line center is approximately described by the Lorentzian function. Since a hydrogen atom has infinitely many p states that participate in the electric dipole interaction, the cross section starts to deviate from the Lorentzian in an asymmetric way in the line wing regions. We investigate this asymmetry in the absorption line profiles around Ly{alpha} and Ly{beta} as a function of the neutral hydrogen column density N{sub HI}. In terms of {Delta}{lambda} {identical_to} {lambda} - {lambda}{sub {alpha}}, we expand the Kramers-Heisenberg formula around Ly{alpha} to find {sigma}({lambda}) {approx_equal} (0.5f{sub 12}){sup 2}{sigma}{sub T}({Delta}{lambda}/{lambda}{sub {alpha}}){sup -2}[1 + 3.792({Delta}{lambda}/{lambda}{sub {alpha}})], where f{sub 12} and {sigma}{sub T} are the oscillator strength of Ly{alpha} and the Thomson scattering cross section, respectively. In terms of {Delta}{lambda}{sub 2} {identical_to} {lambda} - {lambda}{sub {beta}} in the vicinity of Ly{beta}, the total scattering cross section, given as the sum of cross sections for Rayleigh and Raman scattering, is shown to be {sigma}({lambda}) {approx_equal} {sigma}{sub T}(0.5f{sub 13}){sup 2}(1 + R{sub 0})({Delta}{lambda}{sub 2}/{lambda}{sub {beta}}){sup -2}[1 - 24.68({Delta}{lambda}{sub 2}/{lambda}{sub {beta}})] with f{sub 13} and the factor R{sub 0} = 0.1342 being the oscillator strength for Ly{beta} and the ratio of the Raman cross section to Rayleigh cross section, respectively. A redward asymmetry develops around Ly{alpha}, whereas a blue asymmetry is obtained for Ly{beta}. The absorption center shifts are found to be almost proportional to the neutral hydrogen column density.

  14. Temperature Distribution within a Cold Cap during Nuclear Waste Vitrification

    SciTech Connect

    Dixon, Derek R.; Schweiger, Michael J.; Riley, Brian J.; Pokorny, Richard; Hrma, Pavel R.

    2015-07-21

    The kinetics of the feed-to-glass conversion affects the waste vitrification rate in an electric melter. The primary area of interest in this conversion process is the cold cap, a layer of reacting feed on top of molten glass. Knowing the temperature profile within a cold cap will help determine its characteristics and relate them to the rate of glass production. The work presented here provides an experimental determination of the temperature distribution within the cold cap. Since a direct measurement of the temperature field within the cold cap is impracticable, an indirect method was developed where the textural features in a laboratory-made cold cap with a high-level waste feed were mapped as a function of position using optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. To correlate the temperature distribution to microstructures within the cold cap, microstructures were identified of individual feed samples that were heat treated to set temperatures between 400°C and 1200°C and quenched. The temperature distribution within the cold cap was then established by correlating cold-cap regions with the feed samples of nearly identical structures and was compared with the temperature profile from a mathematical model.

  15. 47 CFR 61.41 - Price cap requirements generally.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... party to a merger, acquisition, or similar transaction shall continue to be subject to price cap... no later than one year following the effective date of such merger, acquisition, or similar... subject to price cap regulation, as that term is defined in § 61.3(ee), which are involved in...

  16. IN SITU REMEDIATION OF CONTAMINATED SEDIMENTS - ACTIVE CAPPING TECHNOLOGY

    SciTech Connect

    Knox, A.; Roberts, J.; Paller, M.; Reible, D.

    2010-09-02

    Active capping is a relatively new approach for treating contaminated sediments. It involves applying chemically reactive amendments to the sediment surface. The main role of active caps is to stabilize contaminants in contaminated sediments, lower the bioavailable pool of contaminants, and reduce the release of contaminants to the water column. Metals are common contaminants in many marine and fresh water environments as a result of industrial and military activities. The mobile, soluble forms of metals are generally considered toxic. Induced chemical precipitation of these metals can shift toxic metals from the aqueous phase to a solid, precipitated phase which is often less bioavailable. This approach can be achieved through application of sequestering agents such as rock phosphates, organoclays, zeolites, clay minerals, and biopolymers (e.g., chitosan) in active capping technology. Active capping holds great potential for a more permanent solution that avoids residual risks resulting from contaminant migration through the cap or breaching of the cap. In addition to identifying superior active capping agents, research is needed to optimize application techniques, application rates, and amendment combinations that maximize sequestration of contaminants. A selected set of active capping treatment technologies has been demonstrated at a few sites, including a field demonstration at the Savannah River Site, Aiken, SC. This demonstration has provided useful information on the effects of sequestering agents on metal immobilization, bioavailability, toxicity, and resistance to mechanical disturbance.

  17. Devon island ice cap: core stratigraphy and paleoclimate.

    PubMed

    Koerner, R M

    1977-04-01

    Valuable paleoclimatic information can be gained by studying the distribution of melt layers in deep ice cores. A profile representing the percentage of ice in melt layers in a core drilled from the Devon Island ice cap plotted against both time and depth shows that the ice cap has experienced a period of very warm summers since 1925, following a period of colder summers between about 1600 and 1925. The earlier period was coldest between 1680 and 1730. There is a high correlation between the melt-layer ice percentage and the mass balance of the ice cap. The relation between them suggests that the ice cap mass balance was zero (accumulation equaled ablation) during the colder period but is negative in the present warmer one. There is no firm evidence of a present cooling trend in the summer conditions on the ice cap. A comparison with the melt-layer ice percentage in cores from the other major Canadian Arctic ice caps shows that the variation of summer conditions found for the Devon Island ice cap is representative for all the large ice caps for about 90 percent of the time. There is also a good correlation between melt-layer percentage and summer sea-ice conditions in the archipelago. This suggests that the search for the northwest passage was influenced by changing climate, with the 19th-century peak of the often tragic exploration coinciding with a period of very cold summers. PMID:17733504

  18. Devon island ice cap: core stratigraphy and paleoclimate.

    PubMed

    Koerner, R M

    1977-04-01

    Valuable paleoclimatic information can be gained by studying the distribution of melt layers in deep ice cores. A profile representing the percentage of ice in melt layers in a core drilled from the Devon Island ice cap plotted against both time and depth shows that the ice cap has experienced a period of very warm summers since 1925, following a period of colder summers between about 1600 and 1925. The earlier period was coldest between 1680 and 1730. There is a high correlation between the melt-layer ice percentage and the mass balance of the ice cap. The relation between them suggests that the ice cap mass balance was zero (accumulation equaled ablation) during the colder period but is negative in the present warmer one. There is no firm evidence of a present cooling trend in the summer conditions on the ice cap. A comparison with the melt-layer ice percentage in cores from the other major Canadian Arctic ice caps shows that the variation of summer conditions found for the Devon Island ice cap is representative for all the large ice caps for about 90 percent of the time. There is also a good correlation between melt-layer percentage and summer sea-ice conditions in the archipelago. This suggests that the search for the northwest passage was influenced by changing climate, with the 19th-century peak of the often tragic exploration coinciding with a period of very cold summers.

  19. Better End-Cap Processing for Oxidation-Resistant Polyimides

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann B.; Frimer, Aryeh A.

    2004-01-01

    A class of end-cap compounds that increase the thermo-oxidative stab ility of polyimides of the polymerization of monomeric reactants (PM R) type has been extended. In addition, an improved processing proto col for this class of end-cap compounds has been invented.

  20. Summary of Alpha Particle Transport

    SciTech Connect

    Medley, S.S.; White, R.B.; Zweben, S.J.

    1998-08-19

    This paper summarizes the talks on alpha particle transport which were presented at the 5th International Atomic Energy Agency's Technical Committee Meeting on "Alpha Particles in Fusion Research" held at the Joint European Torus, England in September 1997.