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Sample records for stable primarily nonpolar

  1. Nonpolar solvation dynamics for a nonpolar solute in room ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 130; Issue 1. Nonpolar solvation ... Frank-Condon type excitation of the solute, previously in equilibrium inRTIL solvent, has been modelled by abruptly changing the Lennard-Jones(LJ) diameter of the solute atoms and thereby disrupting the equilibrium situation.

  2. Colloidosomes formed by nonpolar/polar/nonpolar nanoball amphiphiles

    International Nuclear Information System (INIS)

    Chang, Hung-Yu; Sheng, Yu-Jane; Tu, Sheng-Hung; Tsao, Heng-Kwong

    2014-01-01

    Fullerene-based amphiphiles are able to form bilayer vesicles in aqueous solution. In this study, the self-assembly behavior of polymer-tethered nanoballs (NBs) with nonpolar/polar/nonpolar (n-p-n ′ ) motif in a selective solvent is investigated by dissipative particle dynamics. A model NB bears two hydrophobic polymeric arms (n ′ -part) tethered on an extremely hydrophobic NB (n-part) with hydrophilic patch (p-part) patterned on its surface. Dependent on the hydrophobicity and length of tethered arms, three types of aggregates are exhibited, including NB vesicle, core-shell micelle, and segmented-worm. NB vesicles are developed for a wide range of hydrophobic arm lengths. The presence of tethered arms perturbs the bilayer structure formed by NBs. The structural properties including the order parameter, membrane thickness, and area density of the inner leaflet decrease with increasing the arm length. These results indicate that for NBs with longer arms, the extent of interdigitation in the membrane rises so that the overcrowded arms in the inner corona are relaxed. The transport and mechanical properties are evaluated as well. As the arm length grows, the permeability increases significantly because the steric bulk of tethered arms loosens the packing of NBs. By contrast, the membrane tension decreases owing to the reduction of NB/solvent contacts by the polymer corona. Although fusion can reduce membrane tension, NB vesicles show strong resistance to fusion. Moreover, the size-dependent behavior observed in small liposomes is not significant for NB vesicles due to isotropic geometry of NB. Our simulation results are consistent with the experimental findings

  3. Colloidosomes formed by nonpolar/polar/nonpolar nanoball amphiphiles

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Hung-Yu; Sheng, Yu-Jane, E-mail: yjsheng@ntu.edu.tw, E-mail: hktsao@cc.ncu.edu.tw [Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan (China); Tu, Sheng-Hung [Department of Chemical and Materials Engineering, National Central University, Jhongli 320, Taiwan (China); Tsao, Heng-Kwong, E-mail: yjsheng@ntu.edu.tw, E-mail: hktsao@cc.ncu.edu.tw [Department of Chemical and Materials Engineering and Department of Physics, National Central University, Jhongli 320, Taiwan (China)

    2014-08-07

    Fullerene-based amphiphiles are able to form bilayer vesicles in aqueous solution. In this study, the self-assembly behavior of polymer-tethered nanoballs (NBs) with nonpolar/polar/nonpolar (n-p-n{sup ′}) motif in a selective solvent is investigated by dissipative particle dynamics. A model NB bears two hydrophobic polymeric arms (n{sup ′}-part) tethered on an extremely hydrophobic NB (n-part) with hydrophilic patch (p-part) patterned on its surface. Dependent on the hydrophobicity and length of tethered arms, three types of aggregates are exhibited, including NB vesicle, core-shell micelle, and segmented-worm. NB vesicles are developed for a wide range of hydrophobic arm lengths. The presence of tethered arms perturbs the bilayer structure formed by NBs. The structural properties including the order parameter, membrane thickness, and area density of the inner leaflet decrease with increasing the arm length. These results indicate that for NBs with longer arms, the extent of interdigitation in the membrane rises so that the overcrowded arms in the inner corona are relaxed. The transport and mechanical properties are evaluated as well. As the arm length grows, the permeability increases significantly because the steric bulk of tethered arms loosens the packing of NBs. By contrast, the membrane tension decreases owing to the reduction of NB/solvent contacts by the polymer corona. Although fusion can reduce membrane tension, NB vesicles show strong resistance to fusion. Moreover, the size-dependent behavior observed in small liposomes is not significant for NB vesicles due to isotropic geometry of NB. Our simulation results are consistent with the experimental findings.

  4. 1 SUPPLEMENTARY INFORMATION Nonpolar Solvation Dynamics ...

    Indian Academy of Sciences (India)

    IITP

    Nonpolar Solvation Dynamics for a Nonpolar Solute in Room Temperature Ionic Liquid: A. Nonequilibrium Molecular Dynamics Simulation Study. SANDIPA INDRAa and SNEHASIS DASCHAKRABORTYb,* a19, Nischintapur Lane, Santipur, Nadia, West Bengal, 741 004 India. bDepartment of Chemistry, Indian Institute of ...

  5. Combination Bands of the Nonpolar OCS Dimer Involving Intermolecular Modes

    Science.gov (United States)

    Rezaei, M.; Oliaee, J. Norooz; Moazzen-Ahmadi, N.; McKellar, A. R. W.

    2012-06-01

    Spectra of the nonpolar carbonyl sulfide in the region of the OCS ν_1 fundamental band were observed in a supersonic slit-jet apparatus. The expansion gas was probed using radiation from a tunable diode laser employed in a rapid-scan signal averaging mode. Three bands centered at 2085.906, 2103.504, and 2114.979 cm-1 were observed and anlysed. The rotational assignment and fitting of the bands were made by fixing the lower state parameters to those for the ground state of nonpolar (OCS)_2, thus confirming that they were indeed combination bands of the of the most stable isomer of OCS dimer. The band centered at 2085.906 cm-1 is a combination of the forbidden A_g intramolecular mode plus the geared bend intermolecular mode and that centered at 2114.979 cm-1 is a combination of the allowed B_u intramolecular mode plus the intermolecular van der Waals stretch. The combination at 2103.504 cm-1 can be assigned as a band whose upper state involves four quanta of the intramolecular bend or the B_u intramolecular mode plus two quanta of the intermolecular torsional mode. Isotopic work is needed to conclusively identify the vibrational assignment of this band. Our experimental frequencies for the geared bend and van der Waals modes are in good agreement with a recent high level ab initio calculation by Brown et al. J. Brown, Xiao-Gang Wang, T. Carrington Jr. and Richard Dawes, Journal of Chemical Physics, submitted.

  6. EDITORIAL: Non-polar and semipolar nitride semiconductors Non-polar and semipolar nitride semiconductors

    Science.gov (United States)

    Han, Jung; Kneissl, Michael

    2012-02-01

    Throughout the history of group-III-nitride materials and devices, scientific breakthroughs and technological advances have gone hand-in-hand. In the late 1980s and early 1990s, the discovery of the nucleation of smooth (0001) GaN films on c-plane sapphire and the activation of p-dopants in GaN led very quickly to the realization of high-brightness blue and green LEDs, followed by the first demonstration of GaN-based violet laser diodes in the mid 1990s. Today, blue InGaN LEDs boast record external quantum efficiencies exceeding 80% and the emission wavelength of the InGaN-based laser diode has been pushed into the green spectral range. Although these tremenduous advances have already spurred multi-billion dollar industries, there are still a number of scientific questions and technological issues that are unanswered. One key challenge is related to the polar nature of the III-nitride wurtzite crystal. Until a decade ago all research activities had almost exclusively concentrated on (0001)-oriented polar GaN layers and heterostructures. Although the device characteristics seem excellent, the strong polarization fields at GaN heterointerfaces can lead to a significant deterioration of the device performance. Triggered by the first demonstration non-polar GaN quantum wells grown on LiAlO2 by Waltereit and colleagues in 2000, impressive advances in the area of non-polar and semipolar nitride semiconductors and devices have been achieved. Today, a large variety of heterostructures free of polarization fields and exhibiting exceptional electronic and optical properties have been demonstrated, and the fundamental understanding of polar, semipolar and non-polar nitrides has made significant leaps forward. The contributions in this Semiconductor Science and Technology special issue on non-polar and semipolar nitride semiconductors provide an impressive and up-to-date cross-section of all areas of research and device physics in this field. The articles cover a wide range of

  7. High molecular weight non-polar hydrocarbons as pure model substances and in motor oil samples can be ionized without fragmentation by atmospheric pressure chemical ionization mass spectrometry.

    Science.gov (United States)

    Hourani, Nadim; Kuhnert, Nikolai

    2012-10-15

    High molecular weight non-polar hydrocarbons are still difficult to detect by mass spectrometry. Although several studies have targeted this problem, lack of good self-ionization has limited the ability of mass spectrometry to examine these hydrocarbons. Failure to control ion generation in the atmospheric pressure chemical ionization (APCI) source hampers the detection of intact stable gas-phase ions of non-polar hydrocarbon in mass spectrometry. Seventeen non-volatile non-polar hydrocarbons, reported to be difficult to ionize, were examined by an optimized APCI methodology using nitrogen as the reagent gas. All these analytes were successfully ionized as abundant and intact stable [M-H](+) ions without the use of any derivatization or adduct chemistry and without significant fragmentation. Application of the method to real-life hydrocarbon mixtures like light shredder waste and car motor oil was demonstrated. Despite numerous reports to the contrary, it is possible to ionize high molecular weight non-polar hydrocarbons by APCI, omitting the use of additives. This finding represents a significant step towards extending the applicability of mass spectrometry to non-polar hydrocarbon analyses in crude oil, petrochemical products, waste or food. Copyright © 2012 John Wiley & Sons, Ltd.

  8. Determination of inorganic arsenic in algae using bromine halogenation and on-line nonpolar solid phase extraction followed by hydride generation atomic flourescence spectrometry

    Science.gov (United States)

    Accurate, stable and fast analysis of toxic inorganic arsenic (iAs) in complicated and arsenosugar-rich algae matrix is always a challenge. Herein, a novel analytical method for iAs in algae was reported, using bromine halogenation and on-line nonpolar solid phase extraction (SPE) followed by hydrid...

  9. In Vitro Anticancer Activity of a Nonpolar Fraction from Gynostemma pentaphyllum (Thunb. Makino

    Directory of Open Access Journals (Sweden)

    Yantao Li

    2016-01-01

    Full Text Available Gynostemma pentaphyllum (Thunb. Makino (GpM has been widely used in traditional Chinese medicine (TCM for the treatment of various diseases including cancer. Most previous studies have focused primarily on polar fractions of GpM for anticancer activities. In this study, a nonpolar fraction EA1.3A from GpM showed potent growth inhibitory activities against four cancer cell lines with IC50 ranging from 31.62 μg/mL to 38.02 μg/mL. Furthermore, EA1.3A also inhibited the growth of breast cancer cell MDA-MB-453 time-dependently, as well as its colony formation ability. EA1.3A induced apoptosis on MDA-MB-453 cells both dose-dependently and time-dependently as analyzed by flow cytometry and verified by western blotting analysis of apoptosis marker cleaved nuclear poly(ADP-ribose polymerase (cPARP. Additionally, EA1.3A induced cell cycle arrest in G0/G1 phase. Chemical components analysis of EA1.3A by GC-MS revealed that this nonpolar fraction from GpM contains 10 compounds including four alkaloids, three organic esters, two terpenes, and one catechol substance, and all these compounds have not been reported in GpM. In summary, the nonpolar fraction EA1.3A from GpM inhibited cancer cell growth through induction of apoptosis and regulation of cell cycle progression. Our study shed light on new chemical bases for the anticancer activities of GpM and feasibilities to develop new anticancer agents from this widely used medicinal plant.

  10. Long-Wavelength Phonon Scattering in Nonpolar Semiconductors

    DEFF Research Database (Denmark)

    Lawætz, Peter

    1969-01-01

    The long-wavelength acoustic- and optical-phonon scattering of carriers in nonpolar semiconductors is considered from a general point of view. The deformation-potential approximation is defined and it is shown that long-range electrostatic forces give a nontrivial correction to the scattering...... of the very-short-range nature of interactions in a covalent semiconductor....

  11. Solubility of non-polar gases in electrolyte solutions

    Science.gov (United States)

    Walker, R. L., Jr.

    1970-01-01

    Solubility theory describes the effects of both concentration and temperature on solute activity coefficients. It predicts the salting-out effect and the decrease in solubility of non-polar gases with increased electrolyte concentration, and can be used to calculate heats of solution, entropies, and partial molal volumes of dissolved gases

  12. Ab initio density functional theory study of non-polar (101¯0), (112¯0) and semipolar (202¯1) GaN surfaces

    International Nuclear Information System (INIS)

    Mutombo, P.; Romanyuk, O.

    2014-01-01

    The atomic structures of non-polar GaN(101 ¯ 0), (112 ¯ 0) and semipolar GaN(202 ¯ 1), (202 ¯ 1 ¯ ) surfaces were studied using ab initio calculations within density functional theory. The bulk-like truncated (1 × 1) structure with buckled Ga-N or Ga-Ga dimers was found stable on the non-polar GaN(101 ¯ 0) surface in agreement with previous works. Ga-N heterodimers were found energetically stable on the GaN(112 ¯ 0)-(1 × 1) surface. The formation of vacancies and substitution site defects was found unfavorable for non-polar GaN surfaces. Semipolar GaN(202 ¯ 1)-(1 × 1) surface unit cells consist of non-polar (101 ¯ 0) and semipolar (101 ¯ 1) nano-facets. The (101 ¯ 1) nano-facets consist of two-fold coordinated atoms, which form N-N dimers within a (2 × 1) surface unit cell on a GaN(202 ¯ 1) surface. Dimers are not formed on the GaN(202 ¯ 1 ¯ ) surface. The stability of the surfaces with single (101 ¯ 0) or (101 ¯ 1) nano-facets was analyzed. A single non-polar (101 ¯ 0)-(1 × 1) nano-facet was found stable on the GaN(202 ¯ 1) surface, but unstable on the GaN(202 ¯ 1 ¯ ) surface. A single (101 ¯ 1) nano-facet was found unstable. Semipolar GaN surfaces with (202 ¯ 1) and (202 ¯ 1 ¯ ) polarity can be stabilized with a Ga overlayer at Ga-rich experimental conditions.

  13. Electrokinetics of polar liquids in contact with nonpolar surfaces.

    Science.gov (United States)

    Lin, Chih-Hsiu; Ferguson, Gregory S; Chaudhury, Manoj K

    2013-06-25

    Zeta potentials of several polar protic (water, ethylene glycol, and formamide) as well as polar aprotic (dimethyl sulfoxide) liquids were measured in contact with three nonpolar surfaces using closed-cell electroosmosis. The test surfaces were chemisorbed monolayers of alkyl siloxanes, fluoroalkyl siloxanes, and polydimethylsiloxanes (PDMS) grafted on glass slides. All these liquids exhibited substantial electrokinetics in contact with the nonpolar surfaces with these observations: the electrokinetic effect on the fluorocarbon-coated surface is the strongest and on a PDMS grafted surface, the effect is the weakest. Even though these hygroscopic liquids contain small amounts of water, the current models of charging based on the adsorption of hydroxide ions at the interface or the dissociation of pre-existing functionalities (e.g., silanol groups) appear to be insufficient to account for the various facets of the experimental observations. The results illustrate how ubiquitous the phenomenon of electrokinetics is with polar liquids contacting such apparently passive nonpolar surfaces. We hope that these results will inspire further experimental and theoretical studies in this important area of research that has potential practical implications.

  14. Charge transport by inverse micelles in non-polar media

    Science.gov (United States)

    Strubbe, Filip; Neyts, Kristiaan

    2017-11-01

    Charged inverse micelles play an important role in the electrical charging and the electrodynamics of nonpolar colloidal dispersions relevant for applications such as electronic ink displays and liquid toner printing. This review examines the properties and the behavior of charged inverse micelles in microscale devices in the absence of colloidal particles. It is discussed how charge in nonpolar liquids is stabilized in inverse micelles and how conductivity depends on the inverse micelle size, water content and ionic impurities. Frequently used nonpolar surfactant systems are investigated with emphasis on aerosol-OT (AOT) and poly-isobutylene succinimide (PIBS) in dodecane. Charge generation in the bulk by disproportionation is studied from measurements of conductivity as a function of surfactant concentration and from generation currents in quasi steady-state. When a potential difference is applied, the steady-state situation can show electric field screening or complete charge separation. Different regimes of charge transport are identified when a voltage step is applied. It is shown how the transient and steady-state currents depend on the rate of bulk generation, on insulating layers and on the sticking or non-sticking behavior of charged inverse micelles at interfaces. For the cases of AOT and PIBS in dodecane, the magnitude of the generation rate and the type of interaction at the interface are very different.

  15. Foaming properties of monoglycerol fatty acid esters in nonpolar oil systems.

    Science.gov (United States)

    Shrestha, Lok Kumar; Aramaki, Kenji; Kato, Hiroyuki; Takase, Yoshihiko; Kunieda, Hironobu

    2006-09-26

    Foaming properties of monoglycerol fatty acid esters that have different alkyl chain lengths were studied in different nonpolar oils, namely liquid paraffin (LP 70), squalane, and squalene. The effect of the hydrocarbon chain length of the surfactant, the concentration, the nature of the oil, and the temperature on the nonaqueous foam stability was mainly studied. Five weight percent of glycerol alpha-monododecanoate (monolaurin) formed highly stable foams in squalane at 25 degrees C, and the foams were stable for more than 14 h. Foam stability of the monolaurin/LP 70 and the monolaurin/squalene systems are almost similar, and the foams were stable for more than 12 h. Foam stability was decreased as the hydrocarbon chain length of the monoglyceride decreased. In the glycerol alpha-monodecanoate (monocaprin)-oil systems, the foams were stable only for 3-4 h, depending on the nature of the oil. However, the foams formed in the glycerol alpha-monooctanoate (monocaprylin)-oil systems coarsened very quickly, leading to the progressive destruction of foam films, and all of the foams collapsed within a few minutes. Foam stability decreased when the oil was changed from squalane to squalene, in both monocaprin and monolaurin systems. It was observed that, in the dilute regions, these monoglycerides form fine solid dispersions in the aforementioned oils at 25 degrees C. At higher temperatures, the solid melts to isotropic single-liquid or two-liquid phases and the foams formed collapsed within 5 min. Judging from the wide-angle X-ray scattering (WAXS) and the foaming test, it is concluded that the stable foams are mainly caused by the dispersion of the surfactant solids (beta-crystal) and foam stability is largely influenced by the shape and size of the dispersed solid particles.

  16. Electrophoretic Retardation of Colloidal Particles in Nonpolar Liquids

    Directory of Open Access Journals (Sweden)

    Filip Strubbe

    2013-04-01

    Full Text Available We have measured the electrophoretic mobility of single, optically trapped colloidal particles, while gradually depleting the co-ions and counterions in the liquid around the particle by applying a dc voltage. This is achieved in a nonpolar liquid, where charged reverse micelles act as co-ions and counterions. By increasing the dc voltage, the mobility first increases when the concentrations of co-ions and counterions near the particle start to decrease. At sufficiently high dc voltage (around 2 V, the mobility reaches a saturation value when the co-ions and counterions are fully separated. The increase in mobility is larger when the equilibrium ionic strength is higher. The dependence of the experimental data on the equilibrium ionic strength and on the applied voltage is in good agreement with the standard theory of electrophoretic retardation, assuming that the bare particle charge remains constant. This method is useful for studying the electrophoretic retardation effect and charging mechanisms for nonpolar colloids, and it sheds light on previously unexplained particle acceleration in electronic ink devices.

  17. Different Types of Charged-Inverse Micelles in Nonpolar Media.

    Science.gov (United States)

    Prasad, Manoj; Strubbe, Filip; Beunis, Filip; Neyts, Kristiaan

    2016-06-14

    Over the last few years, the electrodynamics of charged inverse micelles (CIMs) in nonpolar liquids and the generation mechanism and properties of newly generated CIMs have been studied extensively for the model system of polyisobutylene succinimide in dodecane. However, the newly generated CIMs, which accumulate at the electrodes when a continuous voltage is applied, behave differently compared to the regular CIMs present in equilibrium in the absence of a field. In this work, we use transient current measurements to investigate the behavior of the newly generated CIMs when the field is reduced to zero or reversed. We demonstrate that the newly generated CIMs do not participate in the diffuse double layer near the electrode formed by the regular CIMs but form an interface layer at the electrode surface. A fraction of the newly generated negative CIMs can be released from this interface layer when the field there becomes zero. The findings of this study provide a better understanding of fundamental processes in nonpolar liquids and are relevant for applications such as electronic ink displays and liquid toner printing.

  18. Switching of charged inverse micelles in non-polar liquids.

    Science.gov (United States)

    Prasad, Manoj; Beunis, Filip; Neyts, Kristiaan; Strubbe, Filip

    2015-11-15

    The electrodynamics of micellar ions in nonpolar liquids are well understood for the case that a voltage is applied or switched off. In this work, the electrodynamics of charged inverse micelles (CIMs) are studied when the applied voltage is switched to the opposite polarity, which is relevant for applications such as electrophoretic displays and liquid toner printing. Transient current measurements are used to characterize the switching of CIMs formed in a solution of surfactant polyisobutylene succinimide in n-dodecane. For reverse voltages with amplitude below 10V the measurements are in good agreement with a drift and diffusion model, confirming the established understanding of CIMs in nonpolar liquids. When the charge content is high, the reversal current shows a characteristic peak which is explained on the basis of dynamic space-charge effects. However, for reverse voltages larger than 10V, the transient currents are influenced by electrohydrodynamic flow in the liquid causing the CIMs to switch faster than predicted by the model. The occurrence of electrohydrodynamic flow is verified by optical tracking of tracer particles. Also, when the polarizing voltage is applied for longer times, an additional current peak emerges which is due to the accumulation of newly generated charges at the electrodes. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Microfluidic mixing of nonpolar liquids by contact charge electrophoresis.

    Science.gov (United States)

    Cartier, Charles A; Drews, Aaron M; Bishop, Kyle J M

    2014-11-07

    We present a simple and effective ratcheted microfluidic mixer that uses contact charge electrophoresis (CCEP) of a micron-scale particle to rapidly mix nonpolar liquids. CCEP combines contact charging and electrostatic actuation to drive the continuous oscillatory motion of a conductive particle between two electrodes subject to a constant (DC) voltage. We show how this oscillatory motion can be harnessed to mix laminar flows by using dielectric "ramps" to direct the particle along non-reciprocal, orbital trajectories, which repeatedly stretch and fold the flowing streams. Complete mixing requires that the speed of the particle is much larger than the fluid velocity such that the particle completes many orbits as the fluid flows through the mixing region. The extent of mixing also depends strongly on the size of the particle and the shape of its trajectory; effective mixers relied on larger particles (comparable to the size of the channel) moving along non-reciprocal orbits. While the present study uses mineral oil as a convenient nonpolar liquid, we also screened fifteen common solvents to determine the applicability of CCEP for mixing other organic liquids. Owing to its simple design and low power requirements (~100 nW), the orbital mixer presented here demonstrates the utility and versatility of ratcheted electrostatic actuation in powering active microfluidic operations.

  20. On the interplay of point defects and Cd in non-polar ZnCdO films

    International Nuclear Information System (INIS)

    Zubiaga, A.; Reurings, F.; Tuomisto, F.; Plazaola, F.; García, J. A.; Kuznetsov, A. Yu.; Egger, W.; Zúñiga-Pérez, J.; Muñoz-Sanjosé, V.

    2013-01-01

    Non-polar ZnCdO films, grown over m- and r-sapphire with a Cd concentration ranging between 0.8% and 5%, have been studied by means of slow positron annihilation spectroscopy (PAS) combined with chemical depth profiling by secondary ion mass spectroscopy and Rutherford back-scattering. Vacancy clusters and Zn vacancies with concentrations up to 10 17 cm −3 and 10 18 cm −3 , respectively, have been measured inside the films. Secondary ion mass spectroscopy results show that most Cd stays inside the ZnCdO film but the diffused atoms can penetrate up to 1.3 μm inside the ZnO buffer. PAS results give an insight to the structure of the meta-stable ZnCdO above the thermodynamical solubility limit of 2%. A correlation between the concentration of vacancy clusters and Cd has been measured. The concentration of Zn vacancies is one order of magnitude larger than in as-grown non-polar ZnO films and the vacancy cluster are, at least partly, created by the aggregation of smaller Zn vacancy related defects. The Zn vacancy related defects and the vacancy clusters accumulate around the Cd atoms as a way to release the strain induced by the substitutional Cd Zn in the ZnO crystal.

  1. On the interplay of point defects and Cd in non-polar ZnCdO films

    Energy Technology Data Exchange (ETDEWEB)

    Zubiaga, A.; Reurings, F.; Tuomisto, F. [Department of Applied Physics, Aalto University, P.O. Box 11100, 00076 Aalto, Espoo (Finland); Plazaola, F. [Elektrizitatea eta Elektronika/Fisika Aplikatua II Sailak, Euskal Herriko Unibertsitatea, Posta Kutxatila 644, 48080 Bilbao (Spain); Garcia, J. A. [Fisika Aplikatua II Saila, Euskal Herriko Unibertsitatea, Posta Kutxatila 644, 48080 Bilbao (Spain); Kuznetsov, A. Yu. [Department of Physics, University of Oslo, P.O. Box 1048 Blindern, NO-0316 Oslo (Norway); Egger, W. [Inst. fuer Angewandte Physik und Messtechnik, Univ. der Bundeswehr Muenchen, 87755 Neubiberg (Germany); Zuniga-Perez, J. [CRHEA CNRS, F-06560 Valbonne (France); Munoz-Sanjose, V. [Dept. de Fisica Aplicada i Electromagnetisme, c/ Doctor Moliner 50, E-46100 Burjassot (Valencia) (Spain)

    2013-01-14

    Non-polar ZnCdO films, grown over m- and r-sapphire with a Cd concentration ranging between 0.8% and 5%, have been studied by means of slow positron annihilation spectroscopy (PAS) combined with chemical depth profiling by secondary ion mass spectroscopy and Rutherford back-scattering. Vacancy clusters and Zn vacancies with concentrations up to 10{sup 17} cm{sup -3} and 10{sup 18} cm{sup -3}, respectively, have been measured inside the films. Secondary ion mass spectroscopy results show that most Cd stays inside the ZnCdO film but the diffused atoms can penetrate up to 1.3 {mu}m inside the ZnO buffer. PAS results give an insight to the structure of the meta-stable ZnCdO above the thermodynamical solubility limit of 2%. A correlation between the concentration of vacancy clusters and Cd has been measured. The concentration of Zn vacancies is one order of magnitude larger than in as-grown non-polar ZnO films and the vacancy cluster are, at least partly, created by the aggregation of smaller Zn vacancy related defects. The Zn vacancy related defects and the vacancy clusters accumulate around the Cd atoms as a way to release the strain induced by the substitutional Cd{sub Zn} in the ZnO crystal.

  2. Electric field induced charging of colloidal particles in a nonpolar liquid.

    Science.gov (United States)

    Schreuer, Caspar; Vandewiele, Stijn; Strubbe, Filip; Neyts, Kristiaan; Beunis, Filip

    2018-04-01

    Colloidal particles in a pure nonpolar solvent are expected to be in a state of dynamic equilibrium where a particle's charge fluctuates around a stable mean value. However, we find that PHSA-coated PMMA microparticles in dodecane gain positive charge over time. We hypothesize that this phenomenon is prompted by the high electric field (∼1 V/µm) that is applied in these measurements. Hence, we expect the reaction rate at which charge builds up on the particle to change when modifying the measurement parameters. Single elementary charging and discharging events can be resolved by measuring the charge of PHSA-coated PMMA particles with optical trapping electrophoresis. With this technique, the influence of the electric field amplitude and frequency, particle size, electrode material and acquired charge can be investigated. The rate of the charging phenomenon is proportional to the amplitude of the applied electric field and the charging stops when the voltage is switched off. We propose a reaction mechanism where the particle sheds negatively charged ions. This mechanism can account for all the experimental observations of the electric field induced charging phenomenon. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Ginzburg-Landau-type theory of nonpolarized spin superconductivity

    Science.gov (United States)

    Lv, Peng; Bao, Zhi-qiang; Guo, Ai-Min; Xie, X. C.; Sun, Qing-Feng

    2017-01-01

    Since the concept of spin superconductor was proposed, all the related studies concentrate on the spin-polarized case. Here, we generalize the study to the spin-non-polarized case. The free energy of nonpolarized spin superconductor is obtained, and Ginzburg-Landau-type equations are derived by using the variational method. These Ginzburg-Landau-type equations can be reduced to the spin-polarized case when the spin direction is fixed. Moreover, the expressions of super linear and angular spin currents inside the superconductor are derived. We demonstrate that the electric field induced by the super spin current is equal to the one induced by an equivalent charge obtained from the second Ginzburg-Landau-type equation, which shows self-consistency of our theory. By applying these Ginzburg-Landau-type equations, the effect of electric field on the superconductor is also studied. These results will help us get a better understanding of the spin superconductor and related topics such as the Bose-Einstein condensate of magnons and spin superfluidity.

  4. Metabolic Activation of Nonpolar Sediment Extracts Results in enhanced Thyroid Hormone Disrupting Potency

    NARCIS (Netherlands)

    Montano, M.; Weiss, J.; Hoffmann, L.; Gutleb, A.C.; Murk, A.J.

    2013-01-01

    Traditional sediment risk assessment predominantly considers the hazard derived from legacy contaminants that are present in nonpolar sediment extracts, such as polychlorinated biphenyls (PCBs), dioxins, furans (PCDD/Fs), and polyaromatic hydrocarbons (PAHs). Although in vivo experiments with these

  5. Growth behavior of GaN film along non-polar [1 1 -2 0] directions

    International Nuclear Information System (INIS)

    Gong Xiaojing; Xu Ke; Wang Jianfeng; Yang Hui; Bian Lifeng; Zhang Jingping; Xu Zijian

    2011-01-01

    We studied the atomic assembly mechanisms of non-polar GaN films by the molecular dynamics method as a function of the N:Ga flux ratio at a fixed adatom energy on non-polar planes. Our study revealed that high quality crystal growth occurred only when off-lattice atoms (which are usually associated with amorphous embryos or defect complexes) formed during deposition were able to move to unoccupied lattice sites by thermally activated diffusion processes, which attests to the experimental difficulties in obtaining smooth surfaces due to dense stacking faults lying in non-polar GaN. Furthermore, surface structures on different planes played an important role. We further suggested favorable conditions for growing high quality GaN films and nano-structures along non-polar directions.

  6. Adsorption of polar, nonpolar, and substituted aromatics to colloidal graphene oxide nanoparticles

    NARCIS (Netherlands)

    Wang, Fang; Haftka, Joris J H; Sinnige, Theo L.; Hermens, Joop L M; Chen, Wei

    2014-01-01

    We conducted batch adsorption experiments to understand the adsorptive properties of colloidal graphene oxide nanoparticles (GONPs) for a range of environmentally relevant aromatics and substituted aromatics, including model nonpolar compounds (pyrene, phenanthrene, naphthalene, and

  7. Electrokinetics of Polar Liquids in Contact with Non-Polar Surfaces

    OpenAIRE

    Lin, Chih-Hsiu; Ferguson, Gregory S.; Chaudhury, Manoj K.

    2014-01-01

    Zeta potentials of several polar protic (water, ethylene glycol, formamide) as well as polar aprotic (dimethyl sulfoxide) liquids were measured in contact with three non-polar surfaces using closed-cell electro-osmosis. The test surfaces were chemisorbed monolayers of alkyl siloxanes, fluoroalkyl siloxanes and polydimethylsiloxanes (PDMS) grafted on glass slides. All these liquids exhibited substantial electrokinetics in contact with the non-polar surfaces with these observations: the electro...

  8. Acousto-optic modulation and deflection of terahertz electromagnetic radiation in nonpolar liquids

    Science.gov (United States)

    Nikitin, P. A.; Voloshinov, V. B.; Gerasimov, V. V.; Knyazev, B. A.

    2017-07-01

    The results of a series of experiments on controlled deflection of electromagnetic radiation of a free-electron laser upon diffraction by an acoustic wave in nonpolar liquids are presented. Acoustic and optical properties of liquids that are transparent in the terahertz range are discussed. It is demonstrated that nonpolar liquids may turn out to be a more efficient acousto-optic interaction medium than dielectric crystals or semiconductors.

  9. The influence of non-polar lipids on tear film dynamics

    KAUST Repository

    Bruna, M.

    2014-04-04

    © 2014 Cambridge University Press. In this paper we examine the effect that physiological non-polar lipids, residing on the surface of an aqueous tear film, have on the film evolution. In our model we track the evolution of the thickness of the non-polar lipid layer, the thickness of the aqueous layer and the concentration of polar lipids which reside at the interface between the two. We also utilise a force balance in the non-polar lipid layer in order to determine its velocity. We show how to obtain previous models in the literature from our model by making particular choices of the parameters. We see the formation of boundary layers in some of these submodels, across which the concentration of polar lipid and the non-polar lipid velocity and film thickness vary. We solve our model numerically for physically realistic parameter values, and we find that the evolution of the aqueous layer and the polar lipid layer are similar to that described by previous authors. However, there are interesting dynamics for the non-polar lipid layer. The effects of altering the key parameters are highlighted and discussed. In particular, we see that the Marangoni number plays a key role in determining how far over the eye the non-polar lipid spreads.

  10. Stable isotopes

    International Nuclear Information System (INIS)

    Evans, D.K.

    1986-01-01

    Seventy-five percent of the world's stable isotope supply comes from one producer, Oak Ridge Nuclear Laboratory (ORNL) in the US. Canadian concern is that foreign needs will be met only after domestic needs, thus creating a shortage of stable isotopes in Canada. This article describes the present situation in Canada (availability and cost) of stable isotopes, the isotope enrichment techniques, and related research programs at Chalk River Nuclear Laboratories (CRNL)

  11. Preparation of polymethylmethacrylate latices in non-polar media

    NARCIS (Netherlands)

    Pathmamanoharan, C.; Slob, C.; Lekkerkerker, H.N.W.

    1989-01-01

    The dispersion polymerization of methylmethacrylate stabilized by poly(12- hydroxy-stearic acid) in hydrocarbon media has been investigated. Unlike earlier results [7] it was found that stable latex particles can be prepared in the initial monomer concentration range 8.5 % to 34 %. To obtain

  12. Human punishment is not primarily motivated by inequality.

    Science.gov (United States)

    Marczyk, Jesse

    2017-01-01

    Previous theorizing about punishment has suggested that humans desire to punish inequality per se. However, the research supporting such an interpretation contains important methodological confounds. The main objective of the current experiment was to remove those confounds in order to test whether generating inequality per se is punished. Participants were recruited from an online market to take part in a wealth-alteration game with an ostensible second player. The participants were given an option to deduct from the other player's payment as punishment for their behavior during the game. The results suggest that human punishment does not appear to be motivated by inequality per se, as inequality that was generated without inflicting costs on others was not reliably punished. Instead, punishment seems to respond primarily to the infliction of costs, with inequality only becoming relevant as a secondary input for punishment decisions. The theoretical significance of this finding is discussed in the context of its possible adaptive value.

  13. Laboratory performance study for passive sampling of nonpolar chemicals in water

    NARCIS (Netherlands)

    Booij, Kees; Smedes, Foppe; Crum, Steven

    2017-01-01

    Two laboratory performance studies with 21 and 11 participants were carried out for passive sampling of nonpolar chemicals in water, using silicone samplers that were deployed for 7 wk and 13 wk at 2 river sites in the Netherlands. Target analytes were polychlorinated biphenyls, polycyclic aromatic

  14. Passive sampling in regulatory chemical monitoring of nonpolar organic compounds in the aquatic environment

    NARCIS (Netherlands)

    Booij, K.; Robinson, C.D.; Burgess, R.M.; Mayer, P.; Roberts, C.A.; Ahrens, L.; Allan, I.J.; Brant, J.; Jones, L.; Kraus, U.R.; Larsen, M.M.; Lepom, P.; Petersen, J.; Pröfrock, D.; Roose, P.; Schäfer, S.; Smedes, F.; Tixier, C.; Vorkamp, K.; Whitehouse, P.

    2016-01-01

    We reviewed compliance monitoring requirements in the EuropeanUnion, the United States, and the Oslo-Paris Convention for the protection of themarine environment of the North-East Atlantic, and evaluated if these are met bypassive sampling methods for nonpolar compounds. The strengths

  15. GC-MS Analysis and Antimicrobial Activities of the Non-polar ...

    African Journals Online (AJOL)

    NICO

    29.7 %) in the leaf extract, amorphene (34.4 %) and valencene (17.9 .... Table 2 Antimicrobial activity of Mundulea sericea non-polar extract. Extract. Microorganism and MIC in µg. S. aureus. B. subtilis. E. coli. P. aeruginosa. C. albicans. Twigs. 50.

  16. The combined toxic effects of nonpolar narcotic chemicals to Pseudokirchneriella subcapitata.

    Science.gov (United States)

    Hsieh, Shih-Hung; Tsai, Kuo-Pei; Chen, Chung-Yuan

    2006-06-01

    This paper presents the toxicity data of 10 nonpolar narcotic chemicals on Pseudokirchneriella subcapitata (green algae) assessed by a new algal toxicity testing technique conducted under air-tight environment. Based on DO production, median effective concentration (EC50) varies from 1.73 mg/L (1-octanol) to 8,040 mg/L (2-propanol). The endpoint of algal growth rate reveals similar sensitivity as that from DO production. Compared to literature data, Pseudokirchneriella subcapitata and Nitrosomonas are apparently more sensitive to nonpolar narcotics than other organisms such as minnow, daphnia, and Tetrahymena pyriformis. Furthermore, good correlations between toxic effects observed from Pseudokirchneriella subcapitata and other aquatic organisms were found. Hence, algal toxicity test can be considered as a surrogate test for estimating the toxicity of nonpolar chemicals to fathead minnow, Microtox, activated sludge, Daphina magna, and Tetrahymena pyriformis. The combined effects of 13 binary mixtures of nonpolar chemicals were investigated using both additive-index method and isobologram analysis. Overall speaking, the joint actions between these chemicals are strictly additive. Model analyses indicate that these compounds act on identical reaction sites or receptors, which verify that these chemicals are of the same toxicity mechanism (narcosis).

  17. Some remarks on the theory of the dielectric constant of non-polar dense gases

    NARCIS (Netherlands)

    Nijboer, B.R.A.

    1975-01-01

    It is pointed out that the usual simple theory of the dielectric constant in isotropic nonpolar media, based on a model with constant polarizability and with dipolar interaction between atoms, is consistent only if the atoms are assumed to have a hard core, so that they cannot approach each other

  18. A case of Choriocarcinoma primarily located in the urinary bladder

    Directory of Open Access Journals (Sweden)

    Gül Türkcü

    2015-12-01

    Full Text Available Choriocarcinoma is a tumor with poor prognosis which usually develops in the uterus and ovaries in females and testes in males. Choriocarcinomas primarily located in the urinary bladder occur extremely rare. In the radiological examination of the 28 year old male patient presented with cough, difficulty in breathing, dysuria and hematuria; lung lesions compatible with metastasis and a mass which was extending inside of the lumen in the anterior wall of the urinary bladder were determined. During the cystoscopic investigation, an incomplete transurethral resection was applied to the tumor. In the histopathological evaluation of the tumor tissue, cells compatible with syncytiotrophoblasts were observed among the polyhedral large mononuclear cells. While positive staining with pancytokeratin, cytokeratin 7, high molecular weight cytokeratin, human plasental lactogen, and human corionic gonadotrophin was observed in the tumor tissue, there was not any staining with epithelial membrane antigen, carcinoembryonic antigen, CD30, p63, and cytokeratin 20. Present histopathological and immunohistochemical findings were evaluated as compatible with coriocarcinoma. Because of being seen rarely, having poor prognosis, causing death due to metastasis, the necessity of holding in mind in the differential diagnosis of high grade urothelial carcinomas, it is purposed to present the case accompanied by literature information.

  19. Double emulsions for the compatibilization of hydrophilic nanocellulose with non-polar polymers and validation in the synthesis of composite fibers.

    Science.gov (United States)

    Carrillo, Carlos A; Nypelö, Tiina; Rojas, Orlando J

    2016-03-14

    A route for the compatibilization of aqueous dispersions of cellulose nanofibrils (CNFs) with a non-polar polymer matrix is proposed to overcome a major challenge in CNF-based material synthesis. Non-ionic surfactants were used in CNF aqueous dispersions equilibrated with an organic phase (for demonstration, a polystyrene solution, PS, was used). Stable water-in-oil-in-water (W/O/W) double emulsions were produced as a result of the compromise between composition and formulation variables. Most remarkably, the proposed route for CNF integration with hydrophobic polymers removed the need for drying or solvent-exchange of the CNF aqueous dispersion prior to processing. The rheological behavior of the double emulsions showed strong shear thinning behavior and facilitated CNF-PS co-mixing in solid nanofibers upon electrospinning. The morphology and thermal properties of the resultant nanofibers revealed that CNFs were efficiently integrated in the hydrophobic matrix which was consistent with the high interfacial area of the precursor double emulsion. In addition, the morphology and quality of the composite nanofibers can be controlled by the conductivity (ionic strength) of the CNF dispersion. Overall, double emulsion systems are proposed as a novel, efficient and scalable platform for CNF co-processing with non-polar systems and they open up the possibility for the redispersion of CNFs after removal of the organic phase.

  20. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1994-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets, with a few more additions - with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers - exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the foree of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc. (orig.)

  1. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1993-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets. with a few more additions -- with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers-exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the forte of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc

  2. Coaxial nanowire resonant tunneling diodes from non-polar AlN/GaN on silicon

    Science.gov (United States)

    Carnevale, S. D.; Marginean, C.; Phillips, P. J.; Kent, T. F.; Sarwar, A. T. M. G.; Mills, M. J.; Myers, R. C.

    2012-04-01

    Resonant tunneling diodes are formed using AlN/GaN core-shell nanowire heterostructures grown by plasma assisted molecular beam epitaxy on n-Si(111) substrates. By using a coaxial geometry, these devices take advantage of non-polar (m-plane) nanowire sidewalls. Device modeling predicts non-polar orientation should enhance resonant tunneling compared to a polar structure, and that AlN double barriers will lead to higher peak-to-valley current ratios compared to AlGaN barriers. Electrical measurements of ensembles of nanowires show negative differential resistance appearing only at cryogenic temperature. Individual nanowire measurements show negative differential resistance at room temperature with peak current density of 5 × 105 A/cm2.

  3. Structural, morphological, and magnetic characteristics of Cu-implanted nonpolar GaN films

    International Nuclear Information System (INIS)

    Sun Lili; Yan Fawang; Zhang Huixiao; Wang Junxi; Zeng Yiping; Wang Guohong; Li Jinmin

    2009-01-01

    Diluted magnetic nonpolar GaN:Cu films have been fabricated by implanting Cu ions into unintentionally doped nonpolar a-plane(112-bar 0) GaN films and a subsequent thermal annealing process. The structural, morphological and magnetic characteristics of the samples have been investigated by means of high-resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM), and superconducting quantum interference device (SQUID). The sample shows a clear ferromagnetism behavior at room temperature. It is significantly shown that with a Cu concentration as low as 0.75% the sample exhibits a saturation magnetization about 0.65 μ B /Cu atom. Moreover, the possible origin of the ferromagnetism for the sample was also discussed briefly.

  4. Broadband non-polarizing terahertz beam splitters with variable split ratio

    KAUST Repository

    Wei, Minggui

    2017-08-15

    Seeking effective terahertz functional devices has always aroused extensive attention. Of particular interest is the terahertz beam splitter. Here, we have proposed, designed, manufactured, and tested a broadband non-polarizing terahertz beam splitter with a variable split ratio based on an all-dielectric metasurface. The metasurface was created by patterning a dielectric surface of the N-step phase gradient and etching to a few hundred micrometers. The conversion efficiency as high as 81% under the normal incidence at 0.7 THz was achieved. Meanwhile, such a splitter works well over a broad frequency range. The split ratio of the proposed design can be continuously tuned by simply shifting the metasurface, and the angle of emergences can also be easily adjusted by choosing the step of phase gradients. The proposed design is non-polarizing, and its performance is kept under different polarizations.

  5. Aromatic residue position on the nonpolar face of class a amphipathic helical peptides determines biological activity.

    Science.gov (United States)

    Datta, Geeta; Epand, Raquel F; Epand, Richard M; Chaddha, Manjula; Kirksey, Matthew A; Garber, David W; Lund-Katz, Sissel; Phillips, Michael C; Hama, Susan; Navab, Mohamad; Fogelman, Alan M; Palgunachari, Mayakonda N; Segrest, Jere P; Anantharamaiah, G M

    2004-06-18

    The apolipoprotein A-I mimetic peptide 4F (Ac-DWFKAFYDKVAEKFKEAF-NH(2)), with four Phe residues on the nonpolar face of the amphipathic alpha-helix, is strongly anti-inflammatory, whereas two 3F analogs (3F(3) and 3F(14)) are not. To understand how changes in helix nonpolar face structure affect function, two additional 3F analogs, Ac-DKLKAFYDKVFEWAKEAF-NH(2) (3F-1) and Ac-DKWKAVYDKFAEAFKEFL-NH(2) (3F-2), were designed using the same amino acid composition as 3F(3) and 3F(14). The aromatic residues in 3F-1 and 3F-2 are near the polar-nonpolar interface and at the center of the nonpolar face of the helix, respectively. Like 4F, but in contrast to 3F(3) and 3F(14), these peptides effectively inhibited lytic peptide-induced hemolysis, oxidized phospholipid-induced monocyte chemotaxis, and scavenged lipid hydroperoxides from low density lipoprotein. High pressure liquid chromatography retention times and monolayer exclusion pressures indicated that there is no direct correlation of peptide function with lipid affinity. Fluorescence studies suggested that, although the peptides bind phospholipids similarly, the Trp residue in 4F, 3F-1, and 3F-2 is less motionally restricted than in 3F(3) and 3F(14). Based on these results and molecular modeling studies, we propose that the arrangement of aromatic residues in class A amphipathic helical molecules regulates entry of reactive oxygen species into peptide-phospholipid complexes, thereby reducing the extent of monocyte chemotaxis, an important step in atherosclerosis.

  6. Observations of Rabi oscillations in a non-polar InGaN quantum dot

    International Nuclear Information System (INIS)

    Reid, Benjamin P. L.; Chan, Christopher C. S.; Taylor, Robert A.; Kocher, Claudius; Zhu, Tongtong; Oehler, Fabrice; Emery, Robert; Oliver, Rachel A.

    2014-01-01

    Experimental observation of Rabi rotations between an exciton excited state and the crystal ground state in a single non-polar InGaN quantum dot is presented. The exciton excited state energy is determined by photoluminescence excitation spectroscopy using two-photon excitation from a pulsed laser. The population of the exciton excited state is seen to undergo power dependent damped Rabi oscillations.

  7. Influence of hydrophobization of fumed oxides on interactions with polar and nonpolar adsorbates

    Science.gov (United States)

    Gun'ko, V. M.; Pakhlov, E. M.; Goncharuk, O. V.; Andriyko, L. S.; Marynin, A. I.; Ukrainets, A. I.; Charmas, B.; Skubiszewska-Zięba, J.; Blitz, J. P.

    2017-11-01

    A variety of unmodified and modified fumed silica A-300 and silica/titania (ST20 and ST76 at 20 and 76 wt.% of titania, respectively) was prepared to analyze features of their interactions with polar and nonpolar adsorbates. The materials were studied using nitrogen adsorption-desorption, ethanol evaporation kinetics, infrared (IR) spectroscopy, thermogravimetry (TG), photon correlation spectroscopy, differential scanning calorimetry (DSC), DSC and TG thermoporometry, and quantum chemistry. Changes in surface structure of modified nanooxides with increasing hydrophobization degree (ΘMS) from 20% to 100% have a strong affect on the textural characteristics of the materials and adsorption-desorption of various adsorbates. Confined space effects enhanced due to the location of adsorbates in narrow voids between nanoparticles lead to freezing-melting point depression for bound polar and nonpolar adsorbates. The behavior of particles of modified nanooxides in aqueous and water/ethanol media is strongly altered due to enhanced aggregations with increasing value of ΘMS. All of these change are non-monotonic functions of ΘMS which affects (i) rearrangement of nanoparticles, (ii) interactions with polar and nonpolar adsorbates, (iii) location of adsorbates in voids of different sizes, (iv) the clustering of adsorbates and formation of nearly bulk structures.

  8. NMR-Based Identification of Metabolites in Polar and Non-Polar Extracts of Avian Liver.

    Science.gov (United States)

    Fathi, Fariba; Brun, Antonio; Rott, Katherine H; Falco Cobra, Paulo; Tonelli, Marco; Eghbalnia, Hamid R; Caviedes-Vidal, Enrique; Karasov, William H; Markley, John L

    2017-11-16

    Metabolites present in liver provide important clues regarding the physiological state of an organism. The aim of this work was to evaluate a protocol for high-throughput NMR-based analysis of polar and non-polar metabolites from a small quantity of liver tissue. We extracted the tissue with a methanol/chloroform/water mixture and isolated the polar metabolites from the methanol/water layer and the non-polar metabolites from the chloroform layer. Following drying, we re-solubilized the fractions for analysis with a 600 MHz NMR spectrometer equipped with a 1.7 mm cryogenic probe. In order to evaluate the feasibility of this protocol for metabolomics studies, we analyzed the metabolic profile of livers from house sparrow ( Passer domesticus ) nestlings raised on two different diets: livers from 10 nestlings raised on a high protein diet (HP) for 4 d and livers from 12 nestlings raised on the HP diet for 3 d and then switched to a high carbohydrate diet (HC) for 1 d. The protocol enabled the detection of 52 polar and nine non-polar metabolites in ¹H NMR spectra of the extracts. We analyzed the lipophilic metabolites by one-way ANOVA to assess statistically significant concentration differences between the two groups. The results of our studies demonstrate that the protocol described here can be exploited for high-throughput screening of small quantities of liver tissue (approx. 100 mg wet mass) obtainable from small animals.

  9. Analysis of Compounds Dissolved in Nonpolar Solvents by Electrospray Ionization on Conductive Nanomaterials

    Science.gov (United States)

    Xia, Bing; Gao, Yuanji; Ji, Baocheng; Ma, Fengwei; Ding, Lisheng; Zhou, Yan

    2018-03-01

    Electrospray ionization mass spectrometry (ESI-MS) technique has limitations in analysis of compounds that are dissolved in nonpolar solvents. In this study, ambient ionization of compounds in solvents that are not "friendly" to electrospray ionization, such as n-hexane, is achieved by conductive nanomaterials spray ionization (CNMSI) on nanomaterial emitters, including carbon nanotubes paper and mesodendritic silver covered metal, which applies high voltages to emitters made of these materials without the assistance of polar solvents. Although the time intensity curves (TIC) commonly vary from 4.5% to 23.7% over analyses, protonated molecular ions were found to be the most abundant species, demonstrating good reproducibility of the technique in terms of ionized species. Higher mass spectrometric responses are observed in analyzing nonpolar systems than polar systems. 2-Methoxyacetophenone, 4-methylacetophenone, benzothiazole, quinolone, and cycloheptanone as low as 2 pg in n-hexane can be directly detected using the developed method. The developed technique expands the analysis capability of ESI-MS for direct, online analysis of nonpolar systems, such as low polarity extracts, normal phase liquid chromatography eluates, and synthetic mixtures. [Figure not available: see fulltext.

  10. Charge transport in non-polar and semi-polar III-V nitride heterostructures

    International Nuclear Information System (INIS)

    Konar, Aniruddha; Verma, Amit; Fang, Tian; Zhao, Pei; Jana, Raj; Jena, Debdeep

    2012-01-01

    Compared to the intense research focus on the optical properties, the transport properties in non-polar and semi-polar III-nitride semiconductors remain relatively unexplored to date. The purpose of this paper is to discuss charge-transport properties in non-polar and semi-polar orientations of GaN in a comparative fashion to what is known for transport in polar orientations. A comprehensive approach is adopted, starting from an investigation of the differences in the electronic bandstructure along different polar orientations of GaN. The polarization fields along various orientations are then discussed, followed by the low-field electron and hole mobilities. A number of scattering mechanisms that are specific to non-polar and semi-polar GaN heterostructures are identified, and their effects are evaluated. Many of these scattering mechanisms originate due to the coupling of polarization with disorder and defects in various incarnations depending on the crystal orientation. The effect of polarization orientation on carrier injection into quantum-well light-emitting diodes is discussed. This paper ends with a discussion of orientation-dependent high-field charge-transport properties including velocity saturation, instabilities and tunneling transport. Possible open problems and opportunities are also discussed. (paper)

  11. The structure, morphology and Raman scattering study on Mn-implanted nonpolar a-plane GaN films

    International Nuclear Information System (INIS)

    Sun Lili; Yan Fawang; Zhang Huixiao; Wang Junxi; Zeng Yiping; Wang Guohong; Li Jinmin

    2009-01-01

    Dilute magnetic nonpolar GaN films with a Curie temperature above room temperature have been fabricated by implanting Mn ions into unintentionally doped nonpolar a-plane (112-bar0) GaN films and a subsequent rapid thermal annealing (RTA) process. The impact of the implantation and RTA on the structure and morphology of the nonpolar GaN films is studied in this paper. The scanning electron microscopy analysis shows that the RTA process can effectively recover the implantation-induced damage to the surface morphology of the sample. The X-ray diffraction and micro-Raman scattering spectroscopy analyses show that the RTA process can just partially recover the implantation-induced crystal deterioration. Therefore, the quality of the Mn-implanted nonpolar GaN films should be improved further for the application in spintronic devices.

  12. Stable beams

    CERN Multimedia

    2015-01-01

    Stable beams: two simple words that carry so much meaning at CERN. When LHC page one switched from "squeeze" to "stable beams" at 10.40 a.m. on Wednesday, 3 June, it triggered scenes of jubilation in control rooms around the CERN sites, as the LHC experiments started to record physics data for the first time in 27 months. This is what CERN is here for, and it’s great to be back in business after such a long period of preparation for the next stage in the LHC adventure.   I’ve said it before, but I’ll say it again. This was a great achievement, and testimony to the hard and dedicated work of so many people in the global CERN community. I could start to list the teams that have contributed, but that would be a mistake. Instead, I’d simply like to say that an achievement as impressive as running the LHC – a machine of superlatives in every respect – takes the combined effort and enthusiasm of everyone ...

  13. Stable isotopes and biomarkers in microbial ecology

    NARCIS (Netherlands)

    Boschker, H.T.S.; Middelburg, J.J.

    2002-01-01

    The use of biomarkers in combination with stable isotope analysis is a new approach in microbial ecology and a number of papers on a variety of subjects have appeared. We will first discuss the techniques for analysing stable isotopes in biomarkers, primarily gas chromatography-combustion-isotope

  14. Comparison of nonpolar III-nitride vertical-cavity surface-emitting lasers with tunnel junction and ITO intracavity contacts

    KAUST Repository

    Leonard, J. T.

    2016-03-01

    We report on the lasing of III-nitride nonpolar, violet, vertical-cavity surface-emitting lasers (VCSELs) with III-nitride tunnel-junction (TJ) intracavity contacts and ion implanted apertures (IIAs). The TJ VCSELs are compared to similar VCSELs with tin-doped indium oxide (ITO) intracavity contacts. Prior to analyzing device results, we consider the relative advantages of III-nitride TJs for blue and green emitting VCSELs. The TJs are shown to be most advantageous for violet and UV VCSELs, operating near or above the absorption edge for ITO, as they significantly reduce the total internal loss in the cavity. However, for longer wavelength III-nitride VCSELs, TJs primarily offer the advantage of improved cavity design flexibility, allowing one to make the p-side thicker using a thick n-type III-nitride TJ intracavity contact. This offers improved lateral current spreading and lower loss, compare to using ITO and p-GaN, respectively. These aspects are particularly important for achieving high-power CW VCSELs, making TJs the ideal intracavity contact for any III-nitride VCSEL. A brief overview of III-nitride TJ growth methods is also given, highlighting the molecular-beam epitaxy (MBE) technique used here. Following this overview, we compare 12 mu m aperture diameter, violet emitting, TJ and ITO VCSEL experimental results, which demonstrate the significant improvement in differential efficiency and peak power resulting from the reduced loss in the TJ design. Specifically, the TJ VCSEL shows a peak power of similar to 550 mu W with a threshold current density of similar to 3.5 kA/cm(2), while the ITO VCSELs show peak powers of similar to 80 mu W and threshold current densities of similar to 7 kA/cm

  15. Comparison of nonpolar III-nitride vertical-cavity surface-emitting lasers with tunnel junction and ITO intracavity contacts

    Science.gov (United States)

    Leonard, J. T.; Young, E. C.; Yonkee, B. P.; Cohen, D. A.; Shen, C.; Margalith, T.; Ng, T. K.; DenBaars, S. P.; Ooi, B. S.; Speck, J. S.; Nakamura, S.

    2016-02-01

    We report on the lasing of III-nitride nonpolar, violet, vertical-cavity surface-emitting lasers (VCSELs) with IIInitride tunnel-junction (TJ) intracavity contacts and ion implanted apertures (IIAs). The TJ VCSELs are compared to similar VCSELs with tin-doped indium oxide (ITO) intracavity contacts. Prior to analyzing device results, we consider the relative advantages of III-nitride TJs for blue and green emitting VCSELs. The TJs are shown to be most advantageous for violet and UV VCSELs, operating near or above the absorption edge for ITO, as they significantly reduce the total internal loss in the cavity. However, for longer wavelength III-nitride VCSELs, TJs primarily offer the advantage of improved cavity design flexibility, allowing one to make the p-side thicker using a thick n-type III-nitride TJ intracavity contact. This offers improved lateral current spreading and lower loss, compare to using ITO and p-GaN, respectively. These aspects are particularly important for achieving high-power CW VCSELs, making TJs the ideal intracavity contact for any III-nitride VCSEL. A brief overview of III-nitride TJ growth methods is also given, highlighting the molecular-beam epitaxy (MBE) technique used here. Following this overview, we compare 12 μm aperture diameter, violet emitting, TJ and ITO VCSEL experimental results, which demonstrate the significant improvement in differential efficiency and peak power resulting from the reduced loss in the TJ design. Specifically, the TJ VCSEL shows a peak power of ~550 μW with a threshold current density of ~3.5 kA/cm2, while the ITO VCSELs show peak powers of ~80 μW and threshold current densities of ~7 kA/cm2.

  16. Determination of inorganic arsenic in algae using bromine halogenation and on-line nonpolar solid phase extraction followed by hydride generation atomic fluorescence spectrometry.

    Science.gov (United States)

    Zhang, Weihong; Qi, Yuehan; Qin, Deyuan; Liu, Jixin; Mao, Xuefei; Chen, Guoying; Wei, Chao; Qian, Yongzhong

    2017-08-01

    Accurate, stable and fast analysis of toxic inorganic arsenic (iAs) in complicated and arsenosugar-rich algae matrix is always a challenge. Herein, a novel analytical method for iAs in algae was reported, using bromine halogenation and on-line nonpolar solid phase extraction (SPE) followed by hydride generation atomic fluorescence spectrometry (HG-AFS). The separation of iAs from algae was first performed by nonpolar SPE sorbent using Br - for arsenic halogenation. Algae samples were extracted with 1% perchloric acid. Then, 1.5mL extract was reduced by 1% thiourea, and simultaneously reacted (for 30min) with 50μL of 10% KBr for converting iAs to AsBr 3 after adding 3.5mL of 70% HCl to 5mL. A polystyrene (PS) resin cartridge was employed to retain arsenicals, which were hydrolyzed, eluted from the PS resin with H 2 O, and categorized as iAs. The total iAs was quantified by HG-AFS. Under optimum conditions, the spiked recoveries of iAs in real algae samples were in the 82-96% range, and the method achieved a desirable limit of detection of 3μgkg -1 . The inter-day relative standard deviations were 4.5% and 4.1% for spiked 100 and 500μgkg -1 respectively, which proved acceptable for this method. For real algae samples analysis, the highest presence of iAs was found in sargassum fusiforme, followed by kelp, seaweed and laver. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Sorption of polar and nonpolar organic contaminants by oil-contaminated soil.

    Science.gov (United States)

    Chen, Hong; Chen, Shuo; Quan, Xie; Zhao, Huimin; Zhang, Yaobin

    2008-12-01

    Sorption of nonpolar (phenanthrene and butylate) and polar (atrazine and diuron) organic chemicals to oil-contaminated soil was examined to investigate oil effects on sorption of organic chemicals and to derive oil-water distribution coefficients (K(oil)). The resulting oil-contaminated soil-water distribution coefficients (K(d)) for phenanthrene demonstrated sorption-enhancing effects at both lower and higher oil concentrations (C(oil)) but sorption-reducing (competitive) effects at intermediate C(oil) (approximately 1 g kg(-1)). Rationalization of the different dominant effects was attempted in terms of the relative aliphatic carbon content which determines the accessibility of the aromatic cores to phenanthrene. Little or no competitive effect occurred for butylate because its sorption was dominated by partitioning. For atrazine and diuron, the changes in K(d) at C(oil) above approximately 1 g kg(-1) were negligible, indicating that the presently investigated oil has little or no effect on the two tested compounds even though the polarity of the oil is much less than soil organic matter (SOM). Therefore, specific interactions with the active groups (aromatic and polar domains) are dominantly responsible for the sorption of polar sorbates, and thus their sorption is controlled by available sorption sites. This study showed that the oil has the potential to be a dominant sorptive phase for nonpolar pollutants when compared to SOM, but hardly so for polar compounds. The results may aid in a better understanding of the role of the aliphatic and aromatic domains in sorption of nonpolar and polar organic pollutants.

  18. Construction of non-polar mutants in Haemophilus influenzae using FLP recombinase technology

    Directory of Open Access Journals (Sweden)

    Baker Beth D

    2008-11-01

    Full Text Available Abstract Background Nontypeable Haemophilus influenzae (NTHi is a gram-negative bacterium that causes otitis media in children as well as other infections of the upper and lower respiratory tract in children and adults. We are employing genetic strategies to identify and characterize virulence determinants in NTHi. NTHi is naturally competent for transformation and thus construction of most mutants by common methodologies is relatively straightforward. However, new methodology was required in order to construct unmarked non-polar mutations in poorly expressed genes whose products are required for transformation. We have adapted the lambda red/FLP-recombinase-mediated strategy used in E. coli for use in NTHi. Results A cassette containing a spectinomycin resistance gene and an rpsL gene flanked by FRT sites was constructed. A PCR amplicon containing 50 base pairs of DNA homologous to the 5' and 3' ends of the gene to be disrupted and the cassette was generated, then recombineered into the target NTHi gene, cloned on a plasmid, using the lambda recombination proteins expressed in E. coli DY380. Thus, the gene of interest was replaced by the cassette. The construct was then transformed into a streptomycin resistant NTHi strain and mutants were selected on spectinomycin-containing growth media. A plasmid derived from pLS88 with a temperature sensitive replicon expressing the FLP recombinase gene under the control of the tet operator/repressor was constructed. This plasmid was electroporated into the NTHi mutant at the permissive temperature and FLP expression was induced using anhydrotetracycline. The recombinase recognizes the FRT sites and eliminates the antibiotic cassette by site-specific recombination, creating the unmarked non-polar mutation. The plasmid is cured by growth of cells at the restrictive temperature. Conclusion The products of the genes in the NTHi pilABCD operon are required for type IV pilus biogenesis and have a role in

  19. Finite element modelling of semi and nonpolar GaN/AlN quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Jurczak, Grzegorz, E-mail: gjurcz@ippt.pan.pl [Department of Computational Science, Institute of Fundamental Technological Research Polish Academy of Sciences, ul. Pawinskiego 5b, 02-106 Warsaw (Poland); Young, Toby D. [Department of Computational Science, Institute of Fundamental Technological Research Polish Academy of Sciences, ul. Pawinskiego 5b, 02-106 Warsaw (Poland)

    2012-11-01

    Highlights: Black-Right-Pointing-Pointer (112{sup Macron }2) and (112{sup Macron }0) GaN/AlN quantum dots as a candidate for light emitting devices. Black-Right-Pointing-Pointer Elastic relaxation scheme shows similarity regardless the type of growth. Black-Right-Pointing-Pointer Spontaneous polarisation follows polar [0 0 0 1] orientation and localisation phenomena is observed. Black-Right-Pointing-Pointer Semipolar-to-nonpolar orientations of a buried QD results in reduction of the electrostatic potential value, peak-to-peak potential drop, and electric field. - Abstract: This paper describes results of a finite element analysis of the elastic and electric field distribution in a semipolar and a nonpolar isolated quantum dot based on previously obtained measurements from transmission electron microscopy. The two quantum dot orientations are each investigated and compared in terms of the resultant piezoelectric fields and their redistribution due to growth orientation and quantum dot geometry/surface effects. Alongside that, a standard polar quantum dot is investigated as a reference-state system. It is found that the geometry of quantum dots grown in alternative orientations affect the elastic strain and, along with orientation dependent spontaneous polarisation, modify the electrostatic potential and the built-in electric fields. A theoretical verification of a reduction in the quantum confined Stark effect by determining the band edge splitting energies for electron and hole states is given.

  20. Nonpolar III-nitride vertical-cavity surface-emitting lasers incorporating an ion implanted aperture

    KAUST Repository

    Leonard, J. T.

    2015-07-06

    © 2015 AIP Publishing LLC. We report on our recent progress in improving the performance of nonpolar III-nitride vertical-cavity surface-emitting lasers (VCSELs) by using an Al ion implanted aperture and employing a multi-layer electron-beam evaporated ITO intracavity contact. The use of an ion implanted aperture improves the lateral confinement over SiNx apertures by enabling a planar ITO design, while the multi-layer ITO contact minimizes scattering losses due to its epitaxially smooth morphology. The reported VCSEL has 10 QWs, with a 3nm quantum well width, 1nm barriers, a 5nm electron-blocking layer, and a 6.95- λ total cavity thickness. These advances yield a single longitudinal mode 406nm nonpolar VCSEL with a low threshold current density (∼16kA/cm2), a peak output power of ∼12μW, and a 100% polarization ratio. The lasing in the current aperture is observed to be spatially non-uniform, which is likely a result of filamentation caused by non-uniform current spreading, lateral optical confinement, contact resistance, and absorption loss.

  1. Dispersing surface-modified imogolite nanotubes in polar and non-polar solvents

    Science.gov (United States)

    Li, Ming; Brant, Jonathan A.

    2018-02-01

    Furthering the development of nanocomposite structures, namely membranes for water treatment applications, requires that methods be developed to ensure nanoparticle dispersion in polar and non-polar solvents, as both are widely used in associated synthesis techniques. Here, we report on a two-step method to graft polyvinylpyrrolidone (PVP), and a one-step method for octadecylphosphonic acid (OPA), onto the outer surfaces of imogolite nanotubes. The goal of these approaches was to improve and maintain nanotube dispersion in polymer compatible polar and non-polar solvents. The PVP coating modified the imogolite surface charge from positive to weakly negative at pH ≤ 9; the OPA made it weakly positive at acidic pH values to negative at pH ≥ 7. The PVP surface coating stabilized the nanotubes through steric hindrance in polar protic, dipolar aprotic, and chloroform. In difference to the PVP, the OPA surface coating allowed the nanotubes to be dispersed in n-hexane and chloroform, but not in the polar solvents. The lack of miscibility in the polar solvents, as well as the better dispersion in n-hexane, was attributed to the stronger hydrophobicity of the OPA polymer relative to the PVP. [Figure not available: see fulltext.

  2. Non-Polar Natural Products from Bromelia laciniosa, Neoglaziovia variegata and Encholirium spectabile (Bromeliaceae

    Directory of Open Access Journals (Sweden)

    Ole Johan Juvik

    2017-09-01

    Full Text Available Extensive regional droughts are already a major problem on all inhabited continents and severe regional droughts are expected to become an increasing and extended problem in the future. Consequently, extended use of available drought resistant food plants should be encouraged. Bromelia laciniosa, Neoglaziovia variegata and Encholirium spectabile are excellent candidates in that respect because they are established drought resistant edible plants from the semi-arid Caatinga region. From a food safety perspective, increased utilization of these plants would necessitate detailed knowledge about their chemical constituents. However, their chemical compositions have previously not been determined. For the first time, the non-polar constituents of B. laciniosa, N. variegata and E. spectabile have been identified. This is the first thorough report on natural products from N. variegata, E. spectabile, and B. laciniosa. Altogether, 20 non-polar natural products were characterized. The identifications were based on hyphenated gas chromatography-high resolution mass spectrometry (GC-HRMS and supported by 1D and 2D Nuclear Magnetic Resonance (NMR plant metabolomics.

  3. Non-Polar Natural Products from Bromelia laciniosa, Neoglaziovia variegata and Encholirium spectabile (Bromeliaceae).

    Science.gov (United States)

    Juvik, Ole Johan; Holmelid, Bjarte; Francis, George W; Lie Andersen, Heidi; de Oliveira, Ana Paula; Gonçalves de Oliveira Júnior, Raimundo; Guedes da Silva Almeida, Jackson Roberto; Fossen, Torgils

    2017-09-06

    Extensive regional droughts are already a major problem on all inhabited continents and severe regional droughts are expected to become an increasing and extended problem in the future. Consequently, extended use of available drought resistant food plants should be encouraged. Bromelia laciniosa , Neoglaziovia variegata and Encholirium spectabile are excellent candidates in that respect because they are established drought resistant edible plants from the semi-arid Caatinga region. From a food safety perspective, increased utilization of these plants would necessitate detailed knowledge about their chemical constituents. However, their chemical compositions have previously not been determined. For the first time, the non-polar constituents of B. laciniosa , N. variegata and E. spectabile have been identified. This is the first thorough report on natural products from N. variegata , E. spectabile , and B. laciniosa . Altogether, 20 non-polar natural products were characterized. The identifications were based on hyphenated gas chromatography-high resolution mass spectrometry (GC-HRMS) and supported by 1D and 2D Nuclear Magnetic Resonance (NMR) plant metabolomics.

  4. Broadband non-polarizing beam splitter based on guided mode resonance effect

    International Nuclear Information System (INIS)

    Ma Jian-Yong; Xu Cheng; Qiang Ying-Huai; Zhu Ya-Bo

    2011-01-01

    A broadband non-polarizing beam splitter (NPBS) operating in the telecommunication C+L band is designed by using the guided mode resonance effect of periodic silicon-on-insulator (SOI) elements. It is shown that this double layer SOI structure can provide ∼50/50 beam ratio with the maximum divergences between reflection and transmission being less than 8% over the spectrum of 1.4 μm∼1.7 μm and 1% in the telecommunication band for both TE and TM polarizations. The physical basis of this broadband non-polarizing property is on the simultaneous excitation of the TE and TM strong modulation waveguide modes near the designed spectrum band. Meanwhile, the electric field distributions for both TE and TM polarizations verify the resonant origin of spectrum in the periodic SOI structure. Furthermore, it is demonstrated with our calculations that the beam splitter proposed here is tolerant to the deviations of incident angle and structure parameters, which make it very easy to be fabricated with current IC technology. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  5. Transient molecular dynamics simulations of liquid viscosity for nonpolar and polar fluids

    Science.gov (United States)

    Thomas, Jason C.; Rowley, Richard L.

    2011-01-01

    A transient molecular dynamics (TMD) method for obtaining fluid viscosity is extended to multisite, force-field models of both nonpolar and polar liquids. The method overlays a sinusoidal velocity profile over the peculiar particle velocities and then records the transient decay of the velocity profile. The viscosity is obtained by regression of the solution of the momentum equation with an appropriate constitutive equation and initial and boundary conditions corresponding to those used in the simulation. The transient velocity decays observed appeared to include both relaxation and retardation effects. The Jeffreys viscoelastic model was found to model accurately the transient responses obtained for multisite models for n-butane, isobutane, n-hexane, water, methanol, and 1-hexanol. TMD viscosities obtained for saturated liquids over a wide range of densities agreed well for the polar fluids, both with nonequilibrium molecular dynamics (NEMD) results using the same force-field models and with correlations based on experimental data. Viscosities obtained for the nonpolar fluids agreed well with the experimental and NEMD results at low to moderate densities, but underpredicted experimental values at higher densities where shear-thinning effects and viscous heating may impact the TMD simulations.

  6. Nonpolar InGaN/GaN Core-Shell Single Nanowire Lasers.

    Science.gov (United States)

    Li, Changyi; Wright, Jeremy B; Liu, Sheng; Lu, Ping; Figiel, Jeffrey J; Leung, Benjamin; Chow, Weng W; Brener, Igal; Koleske, Daniel D; Luk, Ting-Shan; Feezell, Daniel F; Brueck, S R J; Wang, George T

    2017-02-08

    We report lasing from nonpolar p-i-n InGaN/GaN multi-quantum well core-shell single-nanowire lasers by optical pumping at room temperature. The nanowire lasers were fabricated using a hybrid approach consisting of a top-down two-step etch process followed by a bottom-up regrowth process, enabling precise geometrical control and high material gain and optical confinement. The modal gain spectra and the gain curves of the core-shell nanowire lasers were measured using micro-photoluminescence and analyzed using the Hakki-Paoli method. Significantly lower lasing thresholds due to high optical gain were measured compared to previously reported semipolar InGaN/GaN core-shell nanowires, despite significantly shorter cavity lengths and reduced active region volume. Mode simulations show that due to the core-shell architecture, annular-shaped modes have higher optical confinement than solid transverse modes. The results show the viability of this p-i-n nonpolar core-shell nanowire architecture, previously investigated for next-generation light-emitting diodes, as low-threshold, coherent UV-visible nanoscale light emitters, and open a route toward monolithic, integrable, electrically injected single-nanowire lasers operating at room temperature.

  7. A polarity-induced defect mechanism for conductivity and magnetism at polar-nonpolar oxide interfaces.

    Science.gov (United States)

    Yu, Liping; Zunger, Alex

    2014-10-13

    The discovery of conductivity and magnetism at the polar-nonpolar interfaces of insulating nonmagnetic oxides such as LaAlO3 and SrTiO3 has raised prospects for attaining interfacial functionalities absent in the component materials. Yet, the microscopic origin of such emergent phenomena remains unclear, posing obstacles to design of improved functionalities. Here we present first principles calculations of electronic and defect properties of LaAlO3/SrTiO3 interfaces and reveal a unifying mechanism for the origins of both conductivity and magnetism. We demonstrate that the polar discontinuity across the interface triggers thermodynamically the spontaneous formation of certain defects that in turn cancel the polar field induced by the polar discontinuity. The ionization of the spontaneously formed surface oxygen vacancy defects leads to interface conductivity, whereas the unionized Ti-on-Al antisite defects lead to interface magnetism. The proposed mechanism suggests practical design principles for inducing and controlling both conductivity and magnetism at general polar-nonpolar interfaces.

  8. The atomic structure of polar and non-polar InGaN quantum wells and the green gap problem

    Energy Technology Data Exchange (ETDEWEB)

    Humphreys, C.J., E-mail: colin.humphreys@msm.cam.ac.uk [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Griffiths, J.T., E-mail: jg641@cam.ac.uk [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Tang, F., E-mail: ft274@cam.ac.uk [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Oehler, F., E-mail: fabrice.oehler@lpn.cnrs.fr [CNRS/C2N, Paris Sud University, Route de Nozay, 91460 Marcoussis (France); Findlay, S.D., E-mail: scott.findlay@monash.edu [School of Physics and Astronomy, Monash University, Victoria 3800 (Australia); Zheng, C., E-mail: changlin.zheng@monash.edu [Monash Centre for Electron Microscopy, Monash University, Victoria 3800 (Australia); Etheridge, J., E-mail: joanne.etheridge@mcem.monash.edu [Department of Materials Science and Engineering, Monash University, Victoria 3800 (Australia); Martin, T.L., E-mail: tomas.martin@materials.ox.ac.uk [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Bagot, P.A.J., E-mail: paul.bagot@materials.ox.ac.uk [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Moody, M.P., E-mail: michael.moody@materials.ox.ac.uk [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Sutherland, D., E-mail: danny.sutherland@manchester.ac.uk [School of Physics and Astronomy, Photon Science Institute, University of Manchester, Manchester M13 9PL (United Kingdom); Dawson, P., E-mail: philip.dawson@manchester.ac.uk [School of Physics and Astronomy, Photon Science Institute, University of Manchester, Manchester M13 9PL (United Kingdom); Schulz, S., E-mail: stefan.schulz@tyndall.ie [Tyndall National Institute, Lee Maltings Complex, Dyke Parade, Cork (Ireland); and others

    2017-05-15

    Highlights: • We have studied the atomic structure of polar and non-polar InGaN quantum wells. • The non-polar (11-20) InGaN quantum wells contain indium-rich clusters, unlike the polar (0001) quantum wells. • The electrons and holes in the quantum wells are localised by different mechanisms. - Abstract: We have used high resolution transmission electron microscopy (HRTEM), aberration-corrected quantitative scanning transmission electron microscopy (Q-STEM), atom probe tomography (APT) and X-ray diffraction (XRD) to study the atomic structure of (0001) polar and (11-20) non-polar InGaN quantum wells (QWs). This paper provides an overview of the results. Polar (0001) InGaN in QWs is a random alloy, with In replacing Ga randomly. The InGaN QWs have atomic height interface steps, resulting in QW width fluctuations. The electrons are localised at the top QW interface by the built-in electric field and the well-width fluctuations, with a localisation energy of typically 20 meV. The holes are localised near the bottom QW interface, by indium fluctuations in the random alloy, with a localisation energy of typically 60 meV. On the other hand, the non-polar (11-20) InGaN QWs contain nanometre-scale indium-rich clusters which we suggest localise the carriers and produce longer wavelength (lower energy) emission than from random alloy non-polar InGaN QWs of the same average composition. The reason for the indium-rich clusters in non-polar (11-20) InGaN QWs is not yet clear, but may be connected to the lower QW growth temperature for the (11-20) InGaN QWs compared to the (0001) polar InGaN QWs.

  9. Room-temperature ferromagnetism and in-plane magnetic anisotropy characteristics of nonpolar GaN:Mn films

    International Nuclear Information System (INIS)

    Sun Lili; Yan Fawang; Zhang Huixiao; Wang Junxi; Wang Guohong; Zeng Yiping; Li Jinmin

    2009-01-01

    Diluted magnetic nonpolar GaN:Mn films have been fabricated by implanting Mn ions into nonpolar a-plane (112-bar 0) p-type GaN films and a subsequent rapid thermal annealing process. The ferromagnetism properties of the films were studied by means of superconducting quantum interference device (SQUID). Clearly in-plane magnetic anisotropy characteristics of the sample at 10 K were revealed with the direction of the applied magnetic field rotating along the in-plane [0 0 0 1]-axis. Moreover, obvious ferromagnetic properties of the sample up to 350 K were detected by means of the temperature-dependent SQUID.

  10. Precise Molecular Sieving Architectures with Janus Pathways for Both Polar and Nonpolar Molecules.

    Science.gov (United States)

    Liu, Jiangtao; Hua, Dan; Zhang, Yu; Japip, Susilo; Chung, Tai-Shung

    2018-03-01

    Precise molecular sieving architectures with Janus superhighways are constructed via a molecularly engineered interfacial reaction between cyclodextrin (CD) and trimesoyl chloride (TMC). Interestingly, the CD/TMC nanofilms constructed with both hydrophobic inner cavities and hydrophilic channels exhibit exceptionally high permeances for both polar and nonpolar solvents. The precise molecular sieving functions are determined by the type of CD building blocks and the inner cavities of intrinsic 3D hollow bowls. Positron annihilation spectroscopy (PAS) confirms that a larger inner CD cavity tends to generate a larger free volume and higher microporosity. Based on the rejection ratio of various dyes, the estimated molecular weight cutoff of CD/TMC nanofilms follows the trend of α-CD/TMC (320 Da) sieving membrane with intrinsic microporosity containing tunable pore size and sharp pore-size distribution can effectively discriminate molecules with different 3D sizes. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Role of the electronegativity for the interface properties of non-polar heterostructures

    KAUST Repository

    Nazir, Safdar

    2012-04-01

    Density functional theory is used to investigate the interfaces in the non-polar ATiO 3/SrTiO 3 (A=Pb, Ca, Ba) heterostructures. All TiO 2-terminated interfaces show an insulating behavior. By reduction of the O content in the AO, SrO, and TiO 2 layers, metallic interface states develop, due to the occupation of the Ti 3d orbitals. For PbTiO 3/SrTiO 3, the Pb 6p states cross the Fermi energy. O vacancy formation energies depend strictly on the electronegativity and the effective volume of the A ion, while the main characteristics of the interface electronic states are maintained. © Europhysics Letters Association, 2012.

  12. Electrokinetics and behavior near the interface of colloidal particles in non-polar dispersions.

    Science.gov (United States)

    Prasad, Manoj; Strubbe, Filip; Beunis, Filip; Neyts, Kristiaan

    2017-08-23

    The electrokinetics and charging of nonpolar colloidal dispersions subjected to a voltage are investigated by electric current and optical measurements. From electric current measurements in response to an alternating triangular voltage with a peak value of a few hundred volts, we find that polystyrene toner particles are compacted near the electrodes and their charge increases by more than a factor of 20. The important increase of charge is interpreted by a mechanism in which counter charges, which are originally at the particle surface, are desorbed. Optical measurements performed under a dc voltage of the order of a few hundred volts demonstrate that the charge of the particles can again decrease or even be inverted. These phenomena are attributed to the movement of counter charged species from the interface layers onto the surface of the particles. The findings of this study are relevant for electrophoretic displays and liquid toner printing.

  13. Sorptive capacities of lipids determined by passive dosing of non-polar organic chemicals

    DEFF Research Database (Denmark)

    Jahnke, Annika; Kierkegaard, Amelie; Bolinius, Damien

    Lipids often are considered the major partitioning phase for non-polar organic chemicals. What is referred to as “lipid”, however, is a complex matrix consisting of a highly variable mixture of neutral (‘storage’) and polar (‘membrane’) lipids that usually is operationally defined by the extraction......VMS), chlorobenzenes and polychlorinated biphenyls via a common headspace over an olive oil donor phase to transfer the same chemical activity into the samples; iii) sampling of EOM and olive oil controls at different time points; iv) purge-and-trap extraction of the model chemicals onto ENV+ SPE cartridges, elution...... and GC/MS analysis; v) characterization of the lipid composition in all samples via NMR. Our experiments demonstrate that the sorptive capacities of the EOM samples do not differ significantly from the olive oil controls if the EOM consists of neutral lipids only. However, the EOM samples show small...

  14. Investigating stacking faults in nonpolar gallium nitride films using X-ray diffraction

    International Nuclear Information System (INIS)

    Moram, M.A.; Johnston, C.F.; Kappers, M.J.; Humphreys, C.J.

    2009-01-01

    Nonpolar (11-20) GaN films with different basal-plane stacking fault (BSF) densities (determined using transmission electron microscopy) were investigated using X-ray diffraction. Diffuse streaking from I 1 and I 2 BSFs was observed in reciprocal space maps of the 10-10 and 20-20 reflections. X-ray calibration curves for BSF density determination can be plotted using the diffusely scattered intensity of open detector 10-10 or 20-20 ω-scans measured at a fixed, large separation from the peak maximum. However, ab initio determination of stacking fault densities is not possible due to additional broadening from other defects. Similarly, ω-scan peak widths are poor indicators of BSF densities.

  15. Application of classical thermodynamics to the conductivity in non-polar media

    Energy Technology Data Exchange (ETDEWEB)

    Gourdin-Bertin, S.; Chassagne, C. [Environmental Fluid Mechanics, Faculty of Civil Engineering and Geosciences, Delft University of Technology, 2600 GA Delft (Netherlands)

    2016-06-28

    Electrical conductivity in non-polar media is a subject which recently regained interest. If most of experiments and theoretical developments were done more than 50 years ago, new experiments and theories have been recently published. As the electrical conductivity describes, at low field, the equilibrium state of a system, it is natural to apply theories based on equilibrium thermodynamics. In this article, well-established classical thermodynamics and solvations models are applied to recently published data. This enables to get a new insight in intriguing phenomena, such as the linear dependence of the conductivity on the concentration of ionic surfactant and the evaluation of conductivity for the mixture of two miscible fluids, such as alcohol and alcane, which have very different conductivities.

  16. Lipophilic polyelectrolyte gels as super-absorbent polymers for nonpolar organic solvents

    Science.gov (United States)

    Ono, Toshikazu; Sugimoto, Takahiro; Shinkai, Seiji; Sada, Kazuki

    2007-06-01

    Polyelectrolyte gels that are known as super-absorbent polymers swell and absorb water up to several hundred times their dried weights and have become ubiquitous and indispensable materials in many applications. Their superior swelling abilities originate from the electrostatic repulsion between the charges on the polymer chains and the osmotic imbalance between the interior and exterior of the gels. However, no super-absorbent polymers for volatile organic compounds (VOCs), and especially for nonpolar organic solvents (ɛpolymer networks. This expands the potential of polyelectrolytes that have been used only in aqueous solutions or highly polar solvents, and provides soft materials that swell in a variety of media. These materials could find applications as protective barriers for VOCs spilled in the environment and as absorbents for waste oil.

  17. Interaction of polar and nonpolar organic pollutants with soil organic matter: sorption experiments and molecular dynamics simulation.

    Science.gov (United States)

    Ahmed, Ashour A; Thiele-Bruhn, Sören; Aziz, Saadullah G; Hilal, Rifaat H; Elroby, Shaaban A; Al-Youbi, Abdulrahman O; Leinweber, Peter; Kühn, Oliver

    2015-03-01

    The fate of organic pollutants in the environment is influenced by several factors including the type and strength of their interactions with soil components especially SOM. However, a molecular level answer to the question "How organic pollutants interact with SOM?" is still lacking. In order to explore mechanisms of this interaction, we have developed a new SOM model and carried out molecular dynamics (MD) simulations in parallel with sorption experiments. The new SOM model comprises free SOM functional groups (carboxylic acid and naphthalene) as well as SOM cavities (with two different sizes), simulating the soil voids, containing the same SOM functional groups. To examine the effect of the hydrophobicity on the interaction, the organic pollutants hexachlorobenzene (HCB, non-polar) and sulfanilamide (SAA, polar) were considered. The experimental and theoretical investigations explored four major points regarding sorption of SAA and HCB on soil, yielding the following results. 1--The interaction depends on the SOM chemical composition more than the SOM content. 2--The interaction causes a site-specific adsorption on the soil surfaces. 3--Sorption hysteresis occurs, which can be explained by inclusion of these pollutants inside soil voids. 4--The hydrophobic HCB is adsorbed on soil stronger than the hydrophilic SAA. Moreover, the theoretical results showed that HCB forms stable complexes with all SOM models in the aqueous solution, while most of SAA-SOM complexes are accompanied by dissociation into SAA and the free SOM models. The SOM-cavity modeling had a significant effect on binding of organic pollutants to SOM. Both HCB and SAA bind to the SOM models in the order of models with a small cavity>a large cavity>no cavity. Although HCB binds to all SOM models stronger than SAA, the latter is more affected by the presence of the cavity. Finally, HCB and SAA bind to the hydrophobic functional group (naphthalene) stronger than to the hydrophilic one (carboxylic acid

  18. Technetium-99m labelled N,N-ethyldithiocarbamate, a non-polar complex with slow hepatic clearance

    International Nuclear Information System (INIS)

    Pojer, P.M.; Baldas, J.

    1980-05-01

    A sup(99m)Tc-N,N-diethyldithiocarbamate (DDC) complex was prepared using formamidine sulphinic acid as the reducing agent for pertechnetate sup(99m) Tc. The complex was found to be non-polar. In mice the complex localised in the liver and intestines. Urinary excretion was very low and hepatic clearance relatively slow

  19. Creation of High Mobility Two-Dimensional Electron Gases via Strain Induced Polarization at an Otherwise Nonpolar Complex Oxide Interface

    DEFF Research Database (Denmark)

    Chen, Yunzhong; Trier, Felix; Kasama, Takeshi

    2015-01-01

    The discovery of two-dimensional electron gases (2DEGs) in SrTiO3-based heterostructures provides new opportunities for nanoelectronics. Herein, we create a new type of oxide 2DEG by the epitaxial-strain-induced polarization at an otherwise nonpolar perovskite-type interface of CaZrO3/SrTiO3. Rem...

  20. Evaluation of Extraction Protocols for Simultaneous Polar and Non-Polar Yeast Metabolite Analysis Using Multivariate Projection Methods

    Directory of Open Access Journals (Sweden)

    Nicolas P. Tambellini

    2013-07-01

    Full Text Available Metabolomic and lipidomic approaches aim to measure metabolites or lipids in the cell. Metabolite extraction is a key step in obtaining useful and reliable data for successful metabolite studies. Significant efforts have been made to identify the optimal extraction protocol for various platforms and biological systems, for both polar and non-polar metabolites. Here we report an approach utilizing chemoinformatics for systematic comparison of protocols to extract both from a single sample of the model yeast organism Saccharomyces cerevisiae. Three chloroform/methanol/water partitioning based extraction protocols found in literature were evaluated for their effectiveness at reproducibly extracting both polar and non-polar metabolites. Fatty acid methyl esters and methoxyamine/trimethylsilyl derivatized aqueous compounds were analyzed by gas chromatography mass spectrometry to evaluate non-polar or polar metabolite analysis. The comparative breadth and amount of recovered metabolites was evaluated using multivariate projection methods. This approach identified an optimal protocol consisting of 64 identified polar metabolites from 105 ion hits and 12 fatty acids recovered, and will potentially attenuate the error and variation associated with combining metabolite profiles from different samples for untargeted analysis with both polar and non-polar analytes. It also confirmed the value of using multivariate projection methods to compare established extraction protocols.

  1. Non-polar lipids accumulate during storage of transfusion products and do not contribute to the onset of transfusion-related acute lung injury.

    Science.gov (United States)

    Peters, A L; Vervaart, M A T; van Bruggen, R; de Korte, D; Nieuwland, R; Kulik, W; Vlaar, A P J

    2017-01-01

    The accumulation of non-polar lipids arachidonic acid, 5-hydroxyeicosatetraenoic acid (HETE), 12-HETE and 15-HETE during storage of transfusion products may play a role in the onset of transfusion-related acute lung injury (TRALI), a syndrome of respiratory distress after transfusion. We investigated non-polar lipid accumulation in red blood cells (RBCs) stored for 42 days, plasma stored for 7 days at either 4 or 20°C and platelet (PLT) transfusion products stored for 7 days. Furthermore, we investigated whether transfusion of RBCs with increased levels of non-polar lipids induces TRALI in a 'two-hit' human volunteer model. All products were produced following Dutch Blood Bank protocols and are according to European standards. Non-polar lipids were measured with high-performance liquid chromotography followed by mass spectrometry. All non-polar lipids increased in RBCs after 21 days of storage compared to baseline. The non-polar lipid concentration in plasma increased significantly, and the increase was even more pronounced in products stored at 20°C. In platelets, baseline levels of 5-HETE and 15-HETE were higher than in RBCs or plasma. However, the non-polar lipids did not change significantly during storage of PLT products. Infusion of RBCs with increased levels of non-polar lipids did not induce TRALI in LPS-primed human volunteers. We conclude that non-polar lipids accumulate in RBC and plasma transfusion products and that accumulation is temperature dependent. Accumulation of non-polar lipids does not appear to explain the onset of TRALI (Dutch Trial Register - NTR4455). © 2016 International Society of Blood Transfusion.

  2. Stable Isotope Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tissue samples (skin, bone, blood, muscle) are analyzed for stable carbon, stable nitrogen, and stable sulfur analysis. Many samples are used in their entirety for...

  3. Heme and non-heme iron transporters in non-polarized and polarized cells

    Directory of Open Access Journals (Sweden)

    Yasui Yumiko

    2010-06-01

    Full Text Available Abstract Background Heme and non-heme iron from diet, and recycled iron from hemoglobin are important products of the synthesis of iron-containing molecules. In excess, iron is potentially toxic because it can produce reactive oxygen species through the Fenton reaction. Humans can absorb, transport, store, and recycle iron without an excretory system to remove excess iron. Two candidate heme transporters and two iron transporters have been reported thus far. Heme incorporated into cells is degraded by heme oxygenases (HOs, and the iron product is reutilized by the body. To specify the processes of heme uptake and degradation, and the reutilization of iron, we determined the subcellular localizations of these transporters and HOs. Results In this study, we analyzed the subcellular localizations of 2 isoenzymes of HOs, 4 isoforms of divalent metal transporter 1 (DMT1, and 2 candidate heme transporters--heme carrier protein 1 (HCP1 and heme responsive gene-1 (HRG-1--in non-polarized and polarized cells. In non-polarized cells, HCP1, HRG-1, and DMT1A-I are located in the plasma membrane. In polarized cells, they show distinct localizations: HCP1 and DMT1A-I are located in the apical membrane, whereas HRG-1 is located in the basolateral membrane and lysosome. 16Leu at DMT1A-I N-terminal cytosolic domain was found to be crucial for plasma membrane localization. HOs are located in smooth endoplasmic reticulum and colocalize with NADPH-cytochrome P450 reductase. Conclusions HCP1 and DMT1A-I are localized to the apical membrane, and HRG-1 to the basolateral membrane and lysosome. These findings suggest that HCP1 and DMT1A-I have functions in the uptake of dietary heme and non-heme iron. HRG-1 can transport endocytosed heme from the lysosome into the cytosol. These localization studies support a model in which cytosolic heme can be degraded by HOs, and the resulting iron is exported into tissue fluids via the iron transporter ferroportin 1, which is

  4. Breaking the polar-nonpolar division in solvation free energy prediction.

    Science.gov (United States)

    Wang, Bao; Wang, Chengzhang; Wu, Kedi; Wei, Guo-Wei

    2018-02-05

    Implicit solvent models divide solvation free energies into polar and nonpolar additive contributions, whereas polar and nonpolar interactions are inseparable and nonadditive. We present a feature functional theory (FFT) framework to break this ad hoc division. The essential ideas of FFT are as follows: (i) representability assumption: there exists a microscopic feature vector that can uniquely characterize and distinguish one molecule from another; (ii) feature-function relationship assumption: the macroscopic features, including solvation free energy, of a molecule is a functional of microscopic feature vectors; and (iii) similarity assumption: molecules with similar microscopic features have similar macroscopic properties, such as solvation free energies. Based on these assumptions, solvation free energy prediction is carried out in the following protocol. First, we construct a molecular microscopic feature vector that is efficient in characterizing the solvation process using quantum mechanics and Poisson-Boltzmann theory. Microscopic feature vectors are combined with macroscopic features, that is, physical observable, to form extended feature vectors. Additionally, we partition a solvation dataset into queries according to molecular compositions. Moreover, for each target molecule, we adopt a machine learning algorithm for its nearest neighbor search, based on the selected microscopic feature vectors. Finally, from the extended feature vectors of obtained nearest neighbors, we construct a functional of solvation free energy, which is employed to predict the solvation free energy of the target molecule. The proposed FFT model has been extensively validated via a large dataset of 668 molecules. The leave-one-out test gives an optimal root-mean-square error (RMSE) of 1.05 kcal/mol. FFT predictions of SAMPL0, SAMPL1, SAMPL2, SAMPL3, and SAMPL4 challenge sets deliver the RMSEs of 0.61, 1.86, 1.64, 0.86, and 1.14 kcal/mol, respectively. Using a test set of 94

  5. Stable convergence and stable limit theorems

    CERN Document Server

    Häusler, Erich

    2015-01-01

    The authors present a concise but complete exposition of the mathematical theory of stable convergence and give various applications in different areas of probability theory and mathematical statistics to illustrate the usefulness of this concept. Stable convergence holds in many limit theorems of probability theory and statistics – such as the classical central limit theorem – which are usually formulated in terms of convergence in distribution. Originated by Alfred Rényi, the notion of stable convergence is stronger than the classical weak convergence of probability measures. A variety of methods is described which can be used to establish this stronger stable convergence in many limit theorems which were originally formulated only in terms of weak convergence. Naturally, these stronger limit theorems have new and stronger consequences which should not be missed by neglecting the notion of stable convergence. The presentation will be accessible to researchers and advanced students at the master's level...

  6. Sublimation growth of nonpolar AlN single crystals and defect characterization

    Energy Technology Data Exchange (ETDEWEB)

    Satoh, Issei; Arakawa, Satoshi; Tanizaki, Keisuke; Miyanaga, Michimasa; Yamamoto, Yoshiyuki [Sumitomo Electric Industries, Ltd., 1-1-1 Koyakita, Itami, Hyogo 664-0016 (Japan)

    2010-07-15

    Sublimation growth of nonpolar AlN single crystals was investigated. The crystals were prepared in two methods: By slicing along the m -plane from c -plane-grown thick crystals, and by heteroepitaxial growth on m -plane SiC substrates. Defects of the crystals were observed by high-resolution transmission electron microscope. Dislocation density in AlN/SiC (0001) decreased significantly at about 1.5 {mu}m above the interface, while stacking faults initiated from the interface toward the growth surface in AlN/SiC (1-100). With increasing crystal thickness, the dislocation density decreases up to 5 x 10{sup 4}/cm{sup 2} at the thickness of 10 mm. In the AlN single crystal grown on SiC (0001), it is noteworthy that the dislocations are localized around the AlN/SiC interface and that far fewer dislocations occur near the growth surface. High-crystallinity AlN thick single crystals could be grown on SiC (0001) substrates. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Investigating roles of organic and inorganic soil components in sorption of polar and nonpolar aromatic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Shi Xin; Ji Liangliang [State Key Laboratory of Pollution Control and Resource Reuse/School of the Environment, Nanjing University, Jiangsu 210093 (China); Zhu Dongqiang, E-mail: zhud@nju.edu.c [State Key Laboratory of Pollution Control and Resource Reuse/School of the Environment, Nanjing University, Jiangsu 210093 (China)

    2010-01-15

    The main objective of the present study was to assess the roles of various soil components in sorption of organic compounds differing in polarity. Removal of the whole soil organic matter decreased sorption by approximately 86% for nonpolar 1,3,5-trichlorobenzene (TCB), but only 34-54% for highly polar 1,3,5-trinitrobenzene (TNB); however, removal of the extractable humic/fulvic acids did not much affect sorption of the two sorbates. With normalization of solute hydrophobicity, TNB exhibits several orders of magnitude stronger sorption compared with TCB to maize burn residue (black carbon), extracted humic acid and Na{sup +}-saturated montmorillonite clay, suggesting specific sorptive interactions for TNB with the individual model soil components. It was proposed that sorption of TCB to the bulk soil was dominated by hydrophobic partition to the condensed, non-extractable fraction of organic matters (humin/kerogen and black carbon), while interactions with soil clay minerals were an important additional factor for sorption of TNB. - Soil humin and black carbon play a predominant role in sorption of 1,3,5-trichlorobenzene, while polar interactions with soil clay minerals are an important additional factor for sorption of 1,3,5-trinitrobenzene.

  8. Passive sampling for target and nontarget analyses of moderately polar and nonpolar substances in water.

    Science.gov (United States)

    Allan, Ian J; Harman, Christopher; Ranneklev, Sissel B; Thomas, Kevin V; Grung, Merete

    2013-08-01

    The applicability of silicone rubber and low-density polyethylene (LDPE) as passive sampling materials for target and nontarget analyses of moderately polar and nonpolar substances was assessed through a field deployment of samplers along a small, polluted stream in Oslo, Norway. Silicone and LDPE samplers of identical surface area (but different volumes) were deployed at 6 sites in the River Alna for 49 d. Quantitative target analysis by gas chromatography-mass spectrometry (quadrupole, single-ion monitoring mode) demonstrated that masses of polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine compounds absorbed in the 2 polymeric materials were consistent with the current understanding of the control and mode of accumulation in these sampler materials. Some deviation was observed for decabromodiphenyl ether (BDE-209) and may be linked to the large molecular size of this substance, resulting in lower diffusivity in the LDPE. Target and nontarget analyses with gas chromatography coupled to high resolution time-of-flight mass spectrometry allowed the identification of a wide range of chemicals, including organophosphate compounds (OPCs) and musk compounds (galaxolide and tonalid). Semiquantitative analysis revealed enhanced quantities of the OPCs in silicone material, indicating some limitation in the absorption and diffusion of these substances in LDPE. Overall, silicone allows nontarget screening analysis for compounds with a wider range of log octanol-water partition coefficient values than what can be achieved with LDPE. Copyright © 2013 SETAC.

  9. Single charging events on colloidal particles in a nonpolar liquid with surfactant

    Science.gov (United States)

    Schreuer, Caspar; Vandewiele, Stijn; Brans, Toon; Strubbe, Filip; Neyts, Kristiaan; Beunis, Filip

    2018-01-01

    Electrical charging of colloidal particles in nonpolar liquids due to surfactant additives is investigated intensively, motivated by its importance in a variety of applications. Most methods rely on average electrophoretic mobility measurements of many particles, which provide only indirect information on the charging mechanism. In the present work, we present a method that allows us to obtain direct information on the charging mechanism, by measuring the charge fluctuations on individual particles with a precision higher than the elementary charge using optical trapping electrophoresis. We demonstrate the capabilities of the method by studying the influence of added surfactant OLOA 11000 on the charging of single colloidal PMMA particles in dodecane. The particle charge and the frequency of charging events are investigated both below and above the critical micelle concentration (CMC) and with or without applying a DC offset voltage. It is found that at least two separate charging mechanisms are present below the critical micelle concentration. One mechanism is a process where the particle is stripped from negatively charged ionic molecules. An increase in the charging frequency with increased surfactant concentration suggests a second mechanism that involves single surfactant molecules. Above the CMC, neutral inverse micelles can also be involved in the charging process.

  10. Modern estuarine siliceous spiculites, Tasmania, Australia: A non-polar link to Phanerozoic spiculitic cherts

    Science.gov (United States)

    Reid, C. M.; James, N. P.; Kyser, T. K.; Barrett, N.; Hirst, A. J.

    2008-02-01

    Biosiliceous sedimentary rocks are well known from the geologicrecord and many are correctly interpreted to have formed indeep-water or cold-water environments. Shallow non-polar spiculitesare also known from the rock record, yet no modern analog hasbeen documented for such environments. Bathurst Harbour, anestuarine system in southwest Tasmania, provides this much-neededmodern analog. In this system a sharp halocline separates tannin-richlow-salinity surface waters from clear marine bottom waters.Tannins supply few nutrients and substantially reduce lightpenetration to bottom environments, resulting in a thinned photiczone and the mixing of deeper-water sub-photic biotas of softcorals, bryozoans, and sponges with other organisms more typicalof this temperate shallow-water environment. The well-definedhalocline allows a typically marine biota, including echinoderms,to live in bottom waters of this estuarine setting. The bioclasticfactory, producing both carbonate and siliceous particles, existsin marine subphotic bottom waters of incised channel and shallowrocky environments along the shoreline. Extensive organic-richsoft sediments in protected embayments generate few bioclasts,but contain allochthonous sponge spicules transported from theadjacent bioclastic factory. Trapping of organic material withinthe estuarine system lowers sediment pH and promotes dissolutionof carbonate biofragments, resulting in preferential preservationof siliceous sponge spicules. This situation implies that manybiosiliceous neritic deposits in the rock record may be theresult of similar preferential preservation.

  11. Piezoelectricity and rotostriction through polar and non-polar coupled instabilities in bismuth-based piezoceramics.

    Science.gov (United States)

    Acosta, Matias; Schmitt, Ljubomira A; Cazorla, Claudio; Studer, Andrew; Zintler, Alexander; Glaum, Julia; Kleebe, Hans-Joachim; Donner, Wolfgang; Hoffman, Mark; Rödel, Jürgen; Hinterstein, Manuel

    2016-07-01

    Coupling of order parameters provides a means to tune functionality in advanced materials including multiferroics, superconductors, and ionic conductors. We demonstrate that the response of a frustrated ferroelectric state leads to coupling between order parameters under electric field depending on grain orientation. The strain of grains oriented along a specific crystallographic direction, 〈h00〉, is caused by converse piezoelectricity originating from a ferrodistortive tetragonal phase. For 〈hhh〉 oriented grains, the strain results from converse piezoelectricity and rotostriction, as indicated by an antiferrodistortive instability that promotes octahedral tilting in a rhombohedral phase. Both strain mechanisms combined lead to a colossal local strain of (2.4 ± 0.1) % and indicate coupling between oxygen octahedral tilting and polarization, here termed "rotopolarization". These findings were confirmed with electromechanical experiments, in situ neutron diffraction, and in situ transmission electron microscopy in 0.75Bi1/2Na1/2TiO3-0.25SrTiO3. This work demonstrates that polar and non-polar instabilities can cooperate to provide colossal functional responses.

  12. Nanoparticle charge control in nonpolar liquids: insights from small-angle neutron scattering and microelectrophoresis.

    Science.gov (United States)

    Kemp, Roger; Sanchez, Rodrigo; Mutch, Kevin J; Bartlett, Paul

    2010-05-18

    Electrostatic forces are typically produced in low polarity solvents by the addition of surfactants or charge-control additives. Although widely used, there is no consensus on the mechanism by which surfactants control the level of particle charge. We report an investigation using highly sensitive, single particle optical microelectrophoresis measurements combined with a small-angle neutron scattering study to establish the mechanism of charging by the surfactant AOT in the nonpolar solvent n-dodecane. We show that polymer-grafted particles with no chemically bound surface charges only charge above the critical micellar concentration of the surfactant. The surface potential increases gradually with increasing surfactant concentration c, before finally saturating at high c. The increase in the surface potential is correlated to the amount of surfactant adsorbed onto the surface of the particle. Using deuterated AOT and contrast variation techniques, we demonstrate that the surfactant is adsorbed within the polymer layer surrounding the particle core, probably as individual molecules rather than surfactant aggregates. A simple thermodynamic model accounts for the concentration dependence of the observed surface potential.

  13. Investigating roles of organic and inorganic soil components in sorption of polar and nonpolar aromatic compounds.

    Science.gov (United States)

    Shi, Xin; Ji, Liangliang; Zhu, Dongqiang

    2010-01-01

    The main objective of the present study was to assess the roles of various soil components in sorption of organic compounds differing in polarity. Removal of the whole soil organic matter decreased sorption by approximately 86% for nonpolar 1,3,5-trichlorobenzene (TCB), but only 34-54% for highly polar 1,3,5-trinitrobenzene (TNB); however, removal of the extractable humic/fulvic acids did not much affect sorption of the two sorbates. With normalization of solute hydrophobicity, TNB exhibits several orders of magnitude stronger sorption compared with TCB to maize burn residue (black carbon), extracted humic acid and Na(+)-saturated montmorillonite clay, suggesting specific sorptive interactions for TNB with the individual model soil components. It was proposed that sorption of TCB to the bulk soil was dominated by hydrophobic partition to the condensed, non-extractable fraction of organic matters (humin/kerogen and black carbon), while interactions with soil clay minerals were an important additional factor for sorption of TNB.

  14. Piezoelectricity and rotostriction through polar and non-polar coupled instabilities in bismuth-based piezoceramics

    Science.gov (United States)

    Acosta, Matias; Schmitt, Ljubomira A.; Cazorla, Claudio; Studer, Andrew; Zintler, Alexander; Glaum, Julia; Kleebe, Hans-Joachim; Donner, Wolfgang; Hoffman, Mark; Rödel, Jürgen; Hinterstein, Manuel

    2016-07-01

    Coupling of order parameters provides a means to tune functionality in advanced materials including multiferroics, superconductors, and ionic conductors. We demonstrate that the response of a frustrated ferroelectric state leads to coupling between order parameters under electric field depending on grain orientation. The strain of grains oriented along a specific crystallographic direction, , is caused by converse piezoelectricity originating from a ferrodistortive tetragonal phase. For oriented grains, the strain results from converse piezoelectricity and rotostriction, as indicated by an antiferrodistortive instability that promotes octahedral tilting in a rhombohedral phase. Both strain mechanisms combined lead to a colossal local strain of (2.4 ± 0.1) % and indicate coupling between oxygen octahedral tilting and polarization, here termed “rotopolarization”. These findings were confirmed with electromechanical experiments, in situ neutron diffraction, and in situ transmission electron microscopy in 0.75Bi1/2Na1/2TiO3-0.25SrTiO3. This work demonstrates that polar and non-polar instabilities can cooperate to provide colossal functional responses.

  15. Structural investigation of diglycerol monolaurate reverse micelles in nonpolar oils cyclohexane and octane

    International Nuclear Information System (INIS)

    Shrestha, Lok Kumar; Aramaki, Kenji

    2009-01-01

    Structure of diglycerol monolaurate (abbreviated as C 12 G 2 ) micelles in nonpolar oils cyclohexane and n-octane as a function of compositions, temperatures, and surfactant chain length has been investigated by small-angle X-ray scattering (SAXS). The SAXS data were evaluated by the generalized indirect Fourier transformation (GIFT) method and real-space structural information of particles was achieved. Conventional poly(oxyethylene) type nonionic surfactants do not form reverse micelles in oils unless a trace water is added. However, present surfactant C 12 G 2 formed reverse micelle (RM) in cyclohexane and n-octane without addition of water at normal room temperature. A clear signature of one dimensional (1-D) micellar growth was found with increasing C 12 G 2 concentration. On the other hand, increasing temperature or hydrocarbon chain length of surfactant shorten the length of RM, which is essentially a cylinder-to-sphere type transition in the aggregate structure. Drastic changes in the structure of RM, namely, transition of ellipsoidal prolate to long rod-like micelles was observed upon changing oil from cyclohexane to octane. All the microstructural transitions were explained in terms of critical packing parameter. (author)

  16. Homoepitaxial nonpolar (10-10) ZnO/ZnMgO monolithic microcavities: Towards reduced photonic disorder

    Energy Technology Data Exchange (ETDEWEB)

    Zuniga-Perez, J., E-mail: jzp@crhea.cnrs.fr; Kappei, L.; Deparis, C.; Chenot, S.; Leroux, M. [CRHEA-CNRS, Rue Bernard Gregory, 06560 Valbonne (France); Reveret, F.; Jamadi, O.; Leymarie, J. [Clermont Université, Institut Pascal (IP), BP 10448, F-63000 Clermont-Ferrand (France); CNRS, UMR 6602, IP, F-63171 Aubière (France); Grundmann, M. [CRHEA-CNRS, Rue Bernard Gregory, 06560 Valbonne (France); Institut für Experimentelle Physik II, Fakultät für Physik und Geowissenschaften, Universität Leipzig, Linnestr. 5, 04103 Leipzig (Germany); Prado, E. de [CRHEA-CNRS, Rue Bernard Gregory, 06560 Valbonne (France); Departamento de Física Aplicada y Electromagnetismo, Universitat de Valencia, c/Dr Moliner 50, Burjassot, Valencia 46100 (Spain)

    2016-06-20

    Nonpolar ZnO/ZnMgO-based optical microcavities have been grown on (10-10) m-plane ZnO substrates by plasma-assisted molecular beam epitaxy. Reflectivity measurements indicate an exponential increase of the cavity quality factor with the number of layers in the distributed Bragg reflectors. Most importantly, microreflectivity spectra recorded with a spot size in the order of 2 μm show a negligible photonic disorder (well below 1 meV), leading to local quality factors equivalent to those obtained by macroreflectivity. The anisotropic character of the nonpolar heterostructures manifests itself both in the surface features, elongated parallel to the in-plane c direction, and in the optical spectra, with two cavity modes being observed at different energies for orthogonal polarizations.

  17. Wetting behavior of nonpolar nanotubes in simple dipolar liquids for varying nanotube diameter and solute-solvent interactions.

    Science.gov (United States)

    Rana, Malay Kumar; Chandra, Amalendu

    2015-01-21

    Atomistic simulations of model nonpolar nanotubes in a Stockmayer liquid are carried out for varying nanotube diameter and nanotube-solvent interactions to investigate solvophobic interactions in generic dipolar solvents. We have considered model armchair type single-walled nonpolar nanotubes with increasing radii from (5,5) to (12,12). The interactions between solute and solvent molecules are modeled by the well-known Lennard-Jones and repulsive Weeks-Chandler-Andersen potentials. We have investigated the density profiles and microscopic arrangement of Stockmayer molecules, orientational profiles of their dipole vectors, time dependence of their occupation, and also the translational and rotational motion of solvent molecules in confined environments of the cylindrical nanopores and also in their external peripheral regions. The present results of structural and dynamical properties of Stockmayer molecules inside and near atomistically rough nonpolar surfaces including their wetting and dewetting behavior for varying interactions provide a more generic picture of solvophobic effects experienced by simple dipolar liquids without any specific interactions such as hydrogen bonds.

  18. stableGP

    Data.gov (United States)

    National Aeronautics and Space Administration — The code in the stableGP package implements Gaussian process calculations using efficient and numerically stable algorithms. Description of the algorithms is in the...

  19. Effect of polar and non-polar surfaces of ZnO nanostructures on photocatalytic properties

    International Nuclear Information System (INIS)

    Yang Jinghai; Wang Jian; Li Xiuyan; Lang Jihui; Liu Fuzhu; Yang Lili; Zhai Hongju; Gao Ming; Zhao Xiaoting

    2012-01-01

    Highlights: ► Large-scale arrayed ZnO nanocrystals including ZnO hexagonal platforms and hamburger-like samples have been successfully fabricated by a simple hydrothermal method. ► ZnO with hexagonal platform-like morphology exhibited higher photocatalytic activity compared with that of the hamburger-like ZnO nanostructures. ► The theories of expose surfaces and oxygen vacancies were utilized to explain the photocatalytic mechanism. - Abstract: Large-scale arrayed ZnO nanocrystals with two different expose surfaces, including ZnO hexagonal nanoplatforms with the major expose plane of (0 0 0 1) and hamburger-like samples with the nonpolar planes of {101 ¯ 0} mainly exposed, were successfully fabricated by a simple hydrothermal method. Mechanisms for compare the photocatalytic activity of two typical ZnO nanostructures were systematic explained as the key point in the paper. Compared with the hamburger-like ZnO nanostructures, the ZnO with hexagonal platform-like morphology exhibited improved ability on the photocatalytic degradation of Rhodamine B (RhB) in aqueous solution under UV radiation. The relative higher photocatalytic activity of the ZnO hexagonal nanoplatforms was attributed to the exposed polar surfaces and the content of oxygen vacancy on the nanostructures surface. The Zn-terminated (0 0 0 1) polar face and the surface defects are facile to adsorb O 2− and OH − ions, resulting in a greater production rate of O 2 · − and OH· − , hence promoting the photocatalysis reaction.

  20. Interface characterization of atomic layer deposited high-k on non-polar GaN

    Science.gov (United States)

    Jia, Ye; Zeng, Ke; Singisetti, Uttam

    2017-10-01

    The interface properties between dielectrics and semiconductors are crucial for electronic devices. In this work, we report the electrical characterization of the interface properties between atomic layer deposited Al2O3 and HfO2 on non-polar a-plane ( 11 2 ¯ 0 ) and m-plane ( 1 1 ¯ 00 ) GaN grown by hybrid vapor phase epitaxy. A metal oxide semiconductor capacitor (MOSCAP) structure was used to evaluate the interface properties. The impact of annealing on the interface properties was also investigated. The border trap in the oxide, characterized by the capacitance-voltage (C-V) hysteresis loop, was low. The interface state density (Dit), extracted using the ac conductance method, is in the range of 0.5 × 1012/cm2 eV to 7.5 × 1011/cm2 eV within an energy range from 0.2 eV to 0.5 eV below the conduction band minimum. The m-plane GaN MOSCAPs exhibited better interface properties than the a-plane GaN MOSCAPs after annealing. Without annealing, Al2O3 dielectrics had higher border trap density and interface state density compared to HfO2 dielectrics. However, the annealing had different impacts on Al2O3 dielectrics as compared to HfO2. Our results showed that the annealing degraded the quality of the interface in HfO2, but it improved the quality of the interface in Al2O3 devices. The annealing also reduced the positive trapped oxide charge, resulting in a shift of C-V curves towards the positive bias region.

  1. Na+ -K+ -2Cl- Cotransporter (NKCC) Physiological Function in Nonpolarized Cells and Transporting Epithelia.

    Science.gov (United States)

    Delpire, Eric; Gagnon, Kenneth B

    2018-03-25

    Two genes encode the Na + -K + -2Cl - cotransporters, NKCC1 and NKCC2, that mediate the tightly coupled movement of 1Na + , 1K + , and 2Cl - across the plasma membrane of cells. Na + -K + -2Cl - cotransport is driven by the chemical gradient of the three ionic species across the membrane, two of them maintained by the action of the Na + /K + pump. In many cells, NKCC1 accumulates Cl - above its electrochemical potential equilibrium, thereby facilitating Cl - channel-mediated membrane depolarization. In smooth muscle cells, this depolarization facilitates the opening of voltage-sensitive Ca 2+ channels, leading to Ca 2+ influx, and cell contraction. In immature neurons, the depolarization due to a GABA-mediated Cl - conductance produces an excitatory rather than inhibitory response. In many cell types that have lost water, NKCC is activated to help the cells recover their volume. This is specially the case if the cells have also lost Cl - . In combination with the Na + /K + pump, the NKCC's move ions across various specialized epithelia. NKCC1 is involved in Cl - -driven fluid secretion in many exocrine glands, such as sweat, lacrimal, salivary, stomach, pancreas, and intestine. NKCC1 is also involved in K + -driven fluid secretion in inner ear, and possibly in Na + -driven fluid secretion in choroid plexus. In the thick ascending limb of Henle, NKCC2 activity in combination with the Na + /K + pump participates in reabsorbing 30% of the glomerular-filtered Na + . Overall, many critical physiological functions are maintained by the activity of the two Na + -K + -2Cl - cotransporters. In this overview article, we focus on the functional roles of the cotransporters in nonpolarized cells and in epithelia. © 2018 American Physiological Society. Compr Physiol 8:871-901, 2018. Copyright © 2018 American Physiological Society. All rights reserved.

  2. Effect of polar and non-polar surfaces of ZnO nanostructures on photocatalytic properties

    Energy Technology Data Exchange (ETDEWEB)

    Yang Jinghai, E-mail: jhyang1@jlnu.edu.cn [Institute of Condensed State Physics, Jilin Normal University, Siping 136000 (China); Key Laboratory of Functional Materials Physics and Chemistry (Jilin Normal University), Ministry of Education, Siping 136000 (China); Wang Jian; Li Xiuyan; Lang Jihui; Liu Fuzhu; Yang Lili; Zhai Hongju; Gao Ming; Zhao Xiaoting [Institute of Condensed State Physics, Jilin Normal University, Siping 136000 (China); Key Laboratory of Functional Materials Physics and Chemistry (Jilin Normal University), Ministry of Education, Siping 136000 (China)

    2012-07-05

    Highlights: Black-Right-Pointing-Pointer Large-scale arrayed ZnO nanocrystals including ZnO hexagonal platforms and hamburger-like samples have been successfully fabricated by a simple hydrothermal method. Black-Right-Pointing-Pointer ZnO with hexagonal platform-like morphology exhibited higher photocatalytic activity compared with that of the hamburger-like ZnO nanostructures. Black-Right-Pointing-Pointer The theories of expose surfaces and oxygen vacancies were utilized to explain the photocatalytic mechanism. - Abstract: Large-scale arrayed ZnO nanocrystals with two different expose surfaces, including ZnO hexagonal nanoplatforms with the major expose plane of (0 0 0 1) and hamburger-like samples with the nonpolar planes of {l_brace}101{sup Macron }0{r_brace} mainly exposed, were successfully fabricated by a simple hydrothermal method. Mechanisms for compare the photocatalytic activity of two typical ZnO nanostructures were systematic explained as the key point in the paper. Compared with the hamburger-like ZnO nanostructures, the ZnO with hexagonal platform-like morphology exhibited improved ability on the photocatalytic degradation of Rhodamine B (RhB) in aqueous solution under UV radiation. The relative higher photocatalytic activity of the ZnO hexagonal nanoplatforms was attributed to the exposed polar surfaces and the content of oxygen vacancy on the nanostructures surface. The Zn-terminated (0 0 0 1) polar face and the surface defects are facile to adsorb O{sup 2-} and OH{sup -} ions, resulting in a greater production rate of O{sup 2}{center_dot}{sup -} and OH{center_dot}{sup -}, hence promoting the photocatalysis reaction.

  3. Nitrobenzene anti-parallel dimer formation in non-polar solvents

    Directory of Open Access Journals (Sweden)

    Toshiyuki Shikata

    2014-06-01

    Full Text Available We investigated the dielectric and depolarized Rayleigh scattering behaviors of nitrobenzene (NO2-Bz, which is a benzene mono-substituted with a planar molecular frame bearing the large electric dipole moment 4.0 D, in non-polar solvents solutions, such as tetrachloromethane and benzene, at up to 3 THz for the dielectric measurements and 8 THz for the scattering experiments at 20 °C. The dielectric relaxation strength of the system was substantially smaller than the proportionality to the concentration in a concentrated regime and showed a Kirkwood correlation factor markedly lower than unity; gK ∼ 0.65. This observation revealed that NO2-Bz has a tendency to form dimers, (NO2-Bz2, in anti-parallel configurations for the dipole moment with increasing concentration of the two solvents. Both the dielectric and scattering data exhibited fast and slow Debye-type relaxation modes with the characteristic time constants ∼7 and ∼50 ps in a concentrated regime (∼15 and ∼30 ps in a dilute regime, respectively. The fast mode was simply attributed to the rotational motion of the (monomeric NO2-Bz. However, the magnitude of the slow mode was proportional to the square of the concentration in the dilute regime; thus, the mode was assigned to the anti-parallel dimer, (NO2-Bz2, dissociation process, and the slow relaxation time was attributed to the anti-parallel dimer lifetime. The concentration dependencies of both the dielectric and scattering data show that the NO2-Bz molecular processes are controlled through a chemical equilibrium between monomers and anti-parallel dimers, 2NO2-Bz ↔ (NO2-Bz2, due to a strong dipole-dipole interaction between nitro groups.

  4. Which sensory perception is primarily considered, in consumers’ hedonic evaluation of foods?

    DEFF Research Database (Denmark)

    Andersen, Barbara Vad; Brockhoff, Per B.; Hyldig, Grethe

    the consumers primarily paid attention to when rating overall liking and sensory satisfaction, respectively. Four apple-cherry fruit drinks were used, varying in: type of sweetener, and addition of aroma and fibre. The fruit drinks were used in a in a cross-over consumer study on 67 subjects together...... of appearance, odour, taste and texture respectively, and sensory satisfaction. Further, liking of sensory properties differed in relation to overall liking and sensory satisfaction, respectively. Consumers primarily paid attention to liking of taste, when evaluating overall liking and sensory satisfaction...

  5. 29 CFR 780.607 - “Primarily employed” in agriculture.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false âPrimarily employedâ in agriculture. 780.607 Section 780... AGRICULTURE, PROCESSING OF AGRICULTURAL COMMODITIES, AND RELATED SUBJECTS UNDER THE FAIR LABOR STANDARDS ACT Employment in Agriculture and Livestock Auction Operations Under the Section 13(b)(13) Exemption Requirements...

  6. M-CARS and EFISHG study of the influence of a static electric field on a non-polar molecule

    Science.gov (United States)

    Capitaine, E.; Louot, C.; Ould-Moussa, N.; Lefort, C.; Kaneyasu, J. F.; Kano, H.; Pagnoux, D.; Couderc, V.; Leproux, P.

    2016-03-01

    The influence of a static electric field on a non-polar molecule has been studied by means of multiplex coherent anti-Stokes Raman scattering (M-CARS). A parallel measurement of electric field induced second harmonic generation (EFISHG) has also been led. Both techniques suggest a reorientation of the molecule due to the presence of an electric field. This phenomenon can be used to increase the chemical selectivity and the signal to non-resonant background ratio, namely, the sensitivity of the M-CARS spectroscopy.

  7. Free ion yields for nonpolar liquids exposed to 1.6-3.5 keV X-rays

    CERN Document Server

    Holroyd, R A

    1998-01-01

    The yields of free ions formed following absorption of 1.6-3.5 keV X-rays were determined for several nonpolar liquids using a conductivity technique. The yields are much less for X-rays than for gamma rays; this effect is largest for branched hydrocarbons. A minimum in yield is observed around 2 keV. The dependence of G sub f sub i sup o on X-ray energy is in good agreement with computer simulations. For tetramethylsilane a sharp dip in ion yield is observed at the Si ls -> sigma sup * resonance, indicating that the free electron yield is even less at this energy.

  8. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    1982-09-01

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  9. Stable Boundary Layer Issues

    NARCIS (Netherlands)

    Steeneveld, G.J.

    2012-01-01

    Understanding and prediction of the stable atmospheric boundary layer is a challenging task. Many physical processes are relevant in the stable boundary layer, i.e. turbulence, radiation, land surface coupling, orographic turbulent and gravity wave drag, and land surface heterogeneity. The

  10. Evolutionary Stable Strategy

    Indian Academy of Sciences (India)

    IAS Admin

    After Maynard-Smith and Price [1] mathematically derived why a given behaviour or strategy was adopted by a certain proportion of the population at a given time, it was shown that a strategy which is currently stable in a population need not be stable in evolutionary time (across generations). Additionally it was sug-.

  11. Inhibition of cyclophosphamide-induced oxidative stress in rat brain by polar and non-polar extracts of Annatto (Bixa orellana) seeds.

    Science.gov (United States)

    Oboh, Ganiyu; Akomolafe, Toyin L; Adefegha, Stephen A; Adetuyi, Abayomi O

    2011-03-01

    Annatto (Bixa orellana) seeds are widely distributed throughout the Tropics and have been used to provide both colour and flavour to food. This study sought to assess the ability of dietary inclusion of polar (water) and non-polar (chloroform) extracts of Annatto (B. orellana) seeds on cyclophosphamide-induced oxidative stress in rat brain. The total phenol content and antioxidant activities of polar (water) and non-polar (chloroform) extracts of Annatto seeds were determined in vitro and in vivo. The results of the study showed that intraperitoneal administration of cyclophosphamide (75 mg/kg of body weight) caused a significant increase (PAnnatto seed extracts (0.1% and 0.2%) caused dose-dependent significant decrease (P<0.05) in the MDA content of the brain. Likewise, the extracts also caused dose-dependent inhibition of the elevated serum glutamate oxaloacetate transaminase (SGOT), glutamate pyruvate transaminase (SGPT), alkaline phosphatase and total bilirubin. However, the non-polar extract had significantly higher inhibitory effects on the elevated MDA production in brain and serum liver function markers. This higher protective effect of the non-polar extract could be attributed to its higher antioxidant properties as typified by its significantly higher (P<0.05) reducing power, free-radical scavenging and Fe (II) chelating ability. Therefore, dietary inclusion of Annato seed extracts as food colourant could prevent oxidative stress occasioned by cyclophosphamide administration, but the non-polar extract is a better protectant. Copyright © 2010 Elsevier GmbH. All rights reserved.

  12. Nonpolar Surface Modification Using Fatty Acids and Its Effect on Calcite from Mineral Carbonation of Desulfurized Gypsum

    Directory of Open Access Journals (Sweden)

    Chi Wan Jeon

    2018-01-01

    Full Text Available CaCO3 is often used as an additive in many industries. However, additional functions are required to expand its applicability. This entails modification of its physicochemical properties. Accordingly, in this study, a particle surface modification treatment was performed on CaCO3 produced from desulfurized gypsum for a range of industrial applications. In the experiment, fatty acids were used to modify the CaCO3 surface, and the scale of the modification effect was based on the degree of change associated with a polar surface taking on nonpolar surface properties. In the preliminary modification experiment, stearic acid was dissolved in 2-propanol or chloroform, and the extent of the reaction and the active ratio were measured according to the stearic acid concentration. The results showed that the effective active ratio, considering the activity to unit adsorption, was higher in 2-propanol than in chloroform. Consequently, the modification solvent used in the experiment changed the CaCO3 surface from a hydrophilic, polarized form to a hydrophobic, nonpolarized form. These results will also allow the CaCO3 produced to be used as a filler in a range of chemical industries.

  13. Controlling Surface Morphology and Circumventing Secondary Phase Formation in Non-polar m-GaN by Tuning Nitrogen Activity

    Science.gov (United States)

    Chang, C. W.; Wadekar, P. V.; Guo, S. S.; Cheng, Y. J.; Chou, M.; Huang, H. C.; Hsieh, W. C.; Lai, W. C.; Chen, Q. Y.; Tu, L. W.

    2018-01-01

    For the development of non-polar nitrides based optoelectronic devices, high-quality films with smooth surfaces, free of defects or clusters, are critical. In this work, the mechanisms governing the topography and single phase epitaxy of non-polar m-plane gallium nitride ( m-GaN) thin films are studied. The samples were grown using plasma-assisted molecular beam epitaxy on m-plane sapphire substrates. Growth of pure m-GaN thin films, concomitant with smooth surfaces is possible at low radio frequency powers and high growth temperatures as judged by the high resolution x-ray diffraction, field emission scanning electron microscopy, and atomic force microscopy measurements. Defect types and densities are quantified using transmission electron microscopy, while Raman spectroscopy was used to analyze the in-plane stress in the thin films which matches the lattice mismatch analysis. Energy dispersive spectroscopy and cathodoluminescence support a congruent growth and a dominant near band edge emission. From the analysis, a narrow growth window is discovered wherein epitaxial growth of pure m-plane GaN samples free of secondary phases with narrow rocking curves and considerable smooth surfaces are successfully demonstrated.

  14. Solvent-assisted electrospray ionization for direct analysis of various compounds (complex) from low/nonpolar solvents and eluents.

    Science.gov (United States)

    Zhang, Jun-Ting; Wang, Hao-Yang; Zhu, Wei; Cai, Ting-Ting; Guo, Yin-Long

    2014-09-16

    Electrospray ionization (ESI) is a powerful ionization technique with a wide range of applications. However, the analytes in low/nonpolar solvents cannot be analyzed directly in electrospray ionization-mass spectrometry (ESI-MS), because low/nonpolar solvents are incompatible with ESI, because of their low conductivity. To circumvent this problem, we introduce an electrospray-based ionization method termed solvent-assisted electrospray ionization (SAESI). With the help of electrospray solvents at the tip of the spray needle, compounds in "non-electrospray ionization-friendly" solvents can be ionized directly using solvent-assisted electrospray ionization-mass spectrometry (SAESI-MS). The key features that the assistant solvent can be chosen flexibly and makes little interference to samples lead to better ionization performance in detection of organic reaction intermediates and real-time analysis of polymers and chiral drugs separated by gel permeation chromatography (GPC) and normal phase liquid chromatography (NPLC). Furthermore, it can achieve online hydrogen/deuterium (H/D) exchange reaction and even mitigate the signal suppression caused by strong acid modifiers in liquid chromatography. In addition, all parts of this device are commercially available and it only requires two parameters to be optimized, which makes SAESI easy to handle.

  15. Environmental changes affect the assembly of soil bacterial community primarily by mediating stochastic processes.

    Science.gov (United States)

    Zhang, Ximei; Johnston, Eric R; Liu, Wei; Li, Linghao; Han, Xingguo

    2016-01-01

    Both 'species fitness difference'-based deterministic processes, such as competitive exclusion and environmental filtering, and 'species fitness difference'-independent stochastic processes, such as birth/death and dispersal/colonization, can influence the assembly of soil microbial communities. However, how both types of processes are mediated by anthropogenic environmental changes has rarely been explored. Here we report a novel and general pattern that almost all anthropogenic environmental changes that took place in a grassland ecosystem affected soil bacterial community assembly primarily through promoting or restraining stochastic processes. We performed four experiments mimicking 16 types of environmental changes and separated the compositional variation of soil bacterial communities caused by each environmental change into deterministic and stochastic components, with a recently developed method. Briefly, because the difference between control and treatment communities is primarily caused by deterministic processes, the deterministic change was quantified as (mean compositional variation between treatment and control) - (mean compositional variation within control). The difference among replicate treatment communities is primarily caused by stochastic processes, so the stochastic change was estimated as (mean compositional variation within treatment) - (mean compositional variation within control). The absolute of the stochastic change was greater than that of the deterministic change across almost all environmental changes, which was robust for both taxonomic and functional-based criterion. Although the deterministic change may become more important as environmental changes last longer, our findings showed that changes usually occurred through mediating stochastic processes over 5 years, challenging the traditional determinism-dominated view. © 2015 John Wiley & Sons Ltd.

  16. Normal modified stable processes

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Shephard, N.

    2002-01-01

    This paper discusses two classes of distributions, and stochastic processes derived from them: modified stable (MS) laws and normal modified stable (NMS) laws. This extends corresponding results for the generalised inverse Gaussian (GIG) and generalised hyperbolic (GH) or normal generalised inverse...... Gaussian (NGIG) laws. The wider framework thus established provides, in particular, for added flexibility in the modelling of the dynamics of financial time series, of importance especially as regards OU based stochastic volatility models for equities. In the special case of the tempered stable OU process...

  17. Applications of stable isotopes

    International Nuclear Information System (INIS)

    Letolle, R.; Mariotti, A.; Bariac, T.

    1991-06-01

    This report reviews the historical background and the properties of stable isotopes, the methods used for their measurement (mass spectrometry and others), the present technics for isotope enrichment and separation, and at last the various present and foreseeable application (in nuclear energy, physical and chemical research, materials industry and research; tracing in industrial, medical and agronomical tests; the use of natural isotope variations for environmental studies, agronomy, natural resources appraising: water, minerals, energy). Some new possibilities in the use of stable isotope are offered. A last chapter gives the present state and forecast development of stable isotope uses in France and Europe

  18. Temporal integration of loudness in listeners with hearing losses of primarily cochlear origin

    DEFF Research Database (Denmark)

    Buus, Søren; Florentine, Mary; Poulsen, Torben

    1999-01-01

    To investigate how hearing loss of primarily cochlear origin affects the loudness of brief tones, loudness matches between 5- and 200-ms tones were obtained as a function of level for 15 listeners with cochlear impairments and for seven age-matched controls. Three frequencies, usually 0.5, 1, and 4...... kHz, were tested in each listener using a two-interval, two-alternative forced-choice (2I, 2AFC) paradigm with a roving-level, up–down adaptive procedure. Results for the normal listeners generally were consistent with published data [e.g., , J. Acoust Soc. Am. 99, 1633–1644 (1996)]. The amount...

  19. Bilateral Krukenberg Tumours Diagnosed Primarily by Transabdominal Sonography- A Case Report

    Science.gov (United States)

    Padala, Krishna Prasanthi; Mahesh; Gowda, Gautham; Pailoor, Aruna

    2015-01-01

    Krukenberg tumour, also known as carcinoma mucocellulare, is a metastatic adenocarcinoma of ovaries from different primary tumour sites. Gastric carcinoma is most common primary tumour responsible for approximately 50% of Krukenberg tumours. Discrimination between primary ovarian cancer and metastatic tumours in the ovary is important, because their management is different. Here we present a case of female suffering from gastric carcinoma with bilateral Krukenberg tumours, diagnosed primarily by transabdominal sonography. The patient was referred to higher centre for further treatment and followed up. PMID:26816967

  20. Analysing Stable Time Series

    National Research Council Canada - National Science Library

    Adler, Robert

    1997-01-01

    We describe how to take a stable, ARMA, time series through the various stages of model identification, parameter estimation, and diagnostic checking, and accompany the discussion with a goodly number...

  1. Lamin A/C mutation affecting primarily the right side of the heart

    Directory of Open Access Journals (Sweden)

    Laura Ollila

    2013-04-01

    Full Text Available LMNA mutations are amongst the most important causes of familial dilated cardiomyopathy. The most important cause of arrhythmogenic right ventricular cardiomyopathy (ARVC is desmosomal pathology. The aim of the study was to elucidate the role of LMNA mutations among Finnish cardiomyopathy patients. We screened 135 unrelated cardiomyopathy patients for LMNA mutations. Because of unusual phenotype, two patients were screened for the known Finnish ARVC-related mutations of desmosomal genes, and their Plakophilin-2b gene was sequenced. Myocardial samples from two patients were examined by immunohistochemical plakoglobin staining and in one case by electron microscopy. We found a new LMNA mutation Phe237Ser in a family of five affected members with a cardiomyopathy affecting primarily the right side of the heart. The phenotype resembles ARVC but does not fulfill the Task Force Criteria. The main clinical manifestations of the mutation were severe tricuspid insufficiency, right ventricular enlargement and failure. Three of the affected patients died of the heart disease, and the two living patients received heart transplants at ages 44 and 47. Electron microscopy showed nuclear blebbing compatible with laminopathy. Immunohisto - chemical analysis did not suggest desmosomal pathology. No desmosomal mutations were found. The Phe237Ser LMNA mutation causes a phenotype different from traditional cardiolaminopathy. Our findings suggest that cardiomyopathy affecting primarily the right side of the heart is not always caused by desmosomal pathology. Our observations highlight the challenges in classifying cardiomyopathies, as there often is significant overlap between the traditional categories.

  2. Material and device studies for the development of ultra-violet light emitting diodes (UV-LEDS) along polar, non-polar and semi-polar directions

    Science.gov (United States)

    Chandrasekaran, Ramya

    Over the past few years, significant effort was dedicated to the development of ultraviolet light emitting diodes (UV-LEDs) for a variety of applications. Such applications include chemical and biological detection, water purification and solid-state lighting. III-Nitride LEDs based on multiple quantum wells (MQWs) grown along the conventional [0001] (polar) direction suffer from the quantum confined Stark effect (QCSE), due to the existence of strong electric fields that arise from spontaneous and piezoelectric polarization. Thus, there is strong motivation to develop MQW-based III-nitride LED structures grown along non-polar and semi-polar directions. The goal of this dissertation is to develop UV-LEDs along the [0001] polar and [11 2¯ 0] non-polar directions by the method of Molecular Beam Epitaxy (MBE). The polar and non-polar LEDs were grown on the C-plane and R-plane sapphire substrates respectively. This work is a combination of materials science studies related to the nucleation, growth and n- and p-type doping of III-nitride films on these two substrates, as well as device studies related to fabrication and characterization of UV-LEDs. It was observed that the crystallographic orientation of the III-nitride films grown on R-plane sapphire depends strongly on the kinetic conditions of growth of the Aluminum Nitride (AIN) buffer. Specifically, growth of the AIN buffer under group III-rich conditions leads to nitride films having the (11 2¯ 0) non polar planes parallel to the sapphire surface, while growth of the buffer under nitrogen rich conditions leads to nitride films with the (11 2¯ 6) semi-polar planes parallel to the sapphire surface. The electron concentration and mobility for the films grown along the polar, non-polar and semi-polar directions were investigated. P-type doping of Gallium Nitride (GaN) films grown on the nonpolar (11 2¯ 0) plane do not suffer from polarity inversion and thus the material was doped p-type with a hole concentration

  3. Nonpolar organic compounds as PM2.5 source tracers: Investigation of their sources and degradation in the Pearl River Delta, China

    Science.gov (United States)

    Wang, Qiongqiong; Feng, Yongming; Huang, X. H. Hilda; Griffith, Stephen M.; Zhang, Ting; Zhang, Qingyan; Wu, Dui; Yu, Jian Zhen

    2016-10-01

    A group of nonpolar organic compounds (NPOCs) in five compound classes including alkanes, polycyclic aromatic hydrocarbons (PAHs), hopanes, steranes, and 1,3,5-triphenylbenzene were quantified in samples of particulate matter of aerodynamic diameter less than 2.5 μm collected at four sites in the Pearl River Delta (PRD) region, China, over a 2 year period from 2011 to 2012. The four sites include industrial (Nanhai), urban (Guangzhou), urban outskirt (Dongguan), and suburban (Nansha) locations. Some NPOCs are uniquely emitted from particular combustion sources and thereby serving as markers in source apportionment. Based on this multiyear and multisite NPOC data set, spatial and seasonal variations, correlation analysis, and ratio-ratio plots were used to investigate the source information and degradation of NPOC tracers. In summer, NPOCs showed distinct local emission characteristics, with urban sites having much higher concentrations than suburban sites. In winter, regional transport was an important influence on NPOC levels, driving up concentrations at all sampling sites and diminishing an urban-suburban spatial gradient. The lighter NPOCs exhibited more prominent seasonal variations. Such spatiotemporal features suggest that their particle-phase abundance is more influenced by temperature, which is a critical factor in controlling the extent of semivolatile organics partitioned into the aerosol phase. The heavier NPOCs, especially PAHs, showed negligible correlation among the four sites, suggesting more influence from local emissions. Ratio-ratio plots indicate photodegradation and mixing of various sources for the NPOCs in the PRD. A positive matrix factorization (PMF) analysis of this large NPOC data set suggests that heavier NPOCs are more suitable source indicators than lighter NPOCs. Incorporating particle-phase light NPOC concentrations in PMF produces a separate factor, which primarily contains those light NPOCs and likely is not a source factor. Total

  4. Non-polar organic compounds as PM2.5 source tracers: Investigation of their sources and degradation in the Pearl River Delta, China

    Science.gov (United States)

    Wang, Q.; Feng, Y.; Huang, X. H. H.; Griffith, S.; Zhang, T.; Zhang, Q.; Wu, D.; Yu, J.

    2016-12-01

    Nonpolar organic compounds (NPOCs) including alkanes, polycyclic aromatic hydrocarbons (PAHs), hopanes, steranes, and 1,3,5-triphenylbenzene, were quantified in PM2.5 samples at four sites in the Pearl River Delta (PRD) region, China over a two-year period from 2011 to 2012. The four sites include one industrial zone (Nanhai), one urban (Guangzhou), one urban outskirt (Dongguan) and one suburban (Nansha) locations. Some NPOCs are uniquely emitted from particular combustion sources, and thereby serving as convenient markers in source apportionment. Based on this multi-year and multi-site data set, spatial and seasonal variations, correlation analysis and ratio-ratio plots were used to investigate the source information and degradation of NPOC tracers. In summer, NPOCs showed distinct local emission characteristics, with urban sites having much higher concentrations than suburban site. In winter, regional transport was an important influence on NPOC levels, driving up concentrations at all sampling sites and diminishing an urban-suburban spatial gradient. The lighter NPOCs exhibited more prominent seasonal variations, suggesting their particle-phase abundance is more influenced by temperature, a critical factor in controlling the extent of semi-volatile organics partitioned into the aerosol phase. The heavier NPOCs, especially PAHs, showed negligible correlation among the four sites, suggesting more influence from local emissions. Ratio-ratio plots indicate photo-degradation and mixing of various sources for the NPOCs in the PRD. A positive matrix factorization (PMF) analysis of this large NPOC data set suggests that heavier NPOCs are more suitable source indicators than lighter NPOCs. Incorporating particle-phase light NPOC concentrations in PMF produces a separate factor, which primarily contains those light NPOCs and likely is not a source factor. Total NPOC concentrations predicted using Pankow partitioning theory were explored as PMF inputs, however, the PMF

  5. Use of polar and nonpolar fractions as additional information sources for studying thermoxidized virgin olive oils by FTIR

    Directory of Open Access Journals (Sweden)

    Tena, N.

    2014-09-01

    Full Text Available Fourier transform infrared (FTIR spectroscopy has been proposed to study the degradation of virgin olive oils (VOO in samples undergoing thermoxidation. The polar and nonpolar fractions of oxidized oils have been analyzed by FTIR to provide further information on the minor spectral changes taking place during thermoxidation. This information assists in the interpretation of the spectra of the samples. For this purpose polar and nonpolar fractions of 47 VOO samples thermoxidized (190 °C in a fryer were analyzed by FTIR. The time-course change of the band area assigned to single cis double bonds was explained by their correlation with the decrease in oleic acid (adjusted-R2=0.93. The bands assigned to the hydroxyl groups and the first overtone of ester groups was better studied in the spectra collected for the polar and nonpolar fractions, respectively. The bands assigned to peroxide, epoxy, tertiary alcohols and fatty acids were clearly observed in the spectra of the polar fraction while they are not noticeable in the spectra of the oils.La espectroscopía de infrarrojos por transformada de Fourier (FTIR se ha propuesto para estudiar la degradación de los aceites de oliva vírgenes (AOV sujetas a termoxidación. Las fracciones polares y no polares de aceites oxidados se analizaron mediante FTIR para obtener más información sobre los cambios espectrales menores que tienen lugar durante la termoxidación. Esa información ayuda en la interpretación de los espectros de las muestras puras. Con este objetivo, fracciones polares y no polares de 47 AOV termoxidados (190 °C en una freidora se analizaron mediante FTIR. La banda asignada a dobles enlaces cis se explica por su correlación con la disminución de ácido oleico (R2-ajustado=0,93. Las bandas asignadas a los grupos hidroxilos y del primer sobretono de los grupos éster se estudió mejor en los espectros recogidos para la fracción polar y no polar, respectivamente. Grupos asignados a per

  6. The Serotonin Transporter Undergoes Constitutive Internalization and Is Primarily Sorted to Late Endosomes and Lysosomal Degradation*

    Science.gov (United States)

    Rahbek-Clemmensen, Troels; Bay, Tina; Eriksen, Jacob; Gether, Ulrik; Jørgensen, Trine Nygaard

    2014-01-01

    The serotonin transporter (SERT) plays a critical role in regulating serotonin signaling by mediating reuptake of serotonin from the extracellular space. The molecular and cellular mechanisms controlling SERT levels in the membrane remain poorly understood. To study trafficking of the surface resident SERT, two functional epitope-tagged variants were generated. Fusion of a FLAG-tagged one-transmembrane segment protein Tac to the SERT N terminus generated a transporter with an extracellular epitope suited for trafficking studies (TacSERT). Likewise, a construct with an extracellular antibody epitope was generated by introducing an HA (hemagglutinin) tag in the extracellular loop 2 of SERT (HA-SERT). By using TacSERT and HA-SERT in antibody-based internalization assays, we show that SERT undergoes constitutive internalization in a dynamin-dependent manner. Confocal images of constitutively internalized SERT demonstrated that SERT primarily co-localized with the late endosomal/lysosomal marker Rab7, whereas little co-localization was observed with the Rab11, a marker of the “long loop” recycling pathway. This sorting pattern was distinct from that of a prototypical recycling membrane protein, the β2-adrenergic receptor. Furthermore, internalized SERT co-localized with the lysosomal marker LysoTracker and not with transferrin. The sorting pattern was further confirmed by visualizing internalization of SERT using the fluorescent cocaine analog JHC1-64 and by reversible and pulse-chase biotinylation assays showing evidence for lysosomal degradation of the internalized transporter. Finally, we found that SERT internalized in response to stimulation with 12-myristate 13-acetate co-localized primarily with Rab7- and LysoTracker-positive compartments. We conclude that SERT is constitutively internalized and that the internalized transporter is sorted mainly to degradation. PMID:24973209

  7. Calcium stable isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  8. Determination of basicity of neutral organic phosphorus extractants in nonpolar solvents by the 31P NMR method

    International Nuclear Information System (INIS)

    Yakshin, V.V.; Meshcheryakov, N.M.; Il'in, E.G.; Ignatov, M.E.; Laskorin, B.N.

    1984-01-01

    The variant of the NMR method application is developed for quantitative description of acidic-basic properties of neutral organic phosphorus extractants, R 3 P--O (NPE), in non-polar organic solvents. For the NPE basicity determination the dependence of the chemical shift value in NMR 31 P spectra of 0.1 M NPE solutions in the dodecane on sulfuric acid acitivity in aqueous phase at 0-12 M acidity is studied. The linear equation relating NPE basicity and electronic structure of these compounds expressed through the sum: of Kabachnik reaction constants is derived. Linear dependences between the NPE basicity value in dodecane and NPE basicity in nitromethane as well as enthalpies of complexes formation with charge transport with standard acid-iodine in heptane, enthalpies of hydrogen complexes formation with phenol and water have been found

  9. Critical thickness for the formation of misfit dislocations originating from prismatic slip in semipolar and nonpolar III-nitride heterostructures

    KAUST Repository

    Smirnov, A. M.

    2016-01-20

    We calculate the critical thickness for misfit dislocation (MD) formation in lattice mismatched semipolar and nonpolar III-nitride wurtzite semiconductor layers for the case of MDs originated from prismatic slip (PSMDs). It has been shown that there is a switch of stress relaxation modes from generation of basal slip originated MDs to PSMDs after the angle between c-axis in wurtzite crystal structure and the direction of semipolar growth reaches a particular value, e.g., ∼70° for Al0.13Ga0.87N/GaN (h0h̄ 1) semipolar heterostructures. This means that for some semipolar growth orientations of III-nitride heterostructures biaxial relaxation of misfit stress can be realized. The results of modeling are compared to experimental data on the onset of plastic relaxation in AlxGa1−xN/GaN heterostructures.

  10. Measuring polarization dependent dispersion of non-polarizing beam splitter cubes with spectrally resolved white light interferometry

    Science.gov (United States)

    Csonti, K.; Hanyecz, V.; Mészáros, G.; Kovács, A. P.

    2017-06-01

    In this work we have measured the group-delay dispersion of an empty Michelson interferometer for s- and p-polarized light beams applying two different non-polarizing beam splitter cubes. The interference pattern appearing at the output of the interferometer was resolved with two different spectrometers. It was found that the group-delay dispersion of the empty interferometer depended on the polarization directions in case of both beam splitter cubes. The results were checked by inserting a glass plate in the sample arm of the interferometer and similar difference was obtained for the two polarization directions. These results show that to reach high precision, linearly polarized white light beam should be used and the residual dispersion of the empty interferometer should be measured at both polarization directions.

  11. Thermodynamic stability of hydrogen-bonded systems in polar and nonpolar environments.

    Science.gov (United States)

    Pasalić, Hasan; Aquino, Adélia J A; Tunega, Daniel; Haberhauer, Georg; Gerzabek, Martin H; Georg, Herbert C; Moraes, Tatiane F; Coutinho, Kaline; Canuto, Sylvio; Lischka, Hans

    2010-07-30

    The thermodynamic properties of a selected set of benchmark hydrogen-bonded systems (acetic acid dimer and the complexes of acetic acid with acetamide and methanol) was studied with the goal of obtaining detailed information on solvent effects on the hydrogen-bonded interactions using water, chloroform, and n-heptane as representatives for a wide range in the dielectric constant. Solvent effects were investigated using both explicit and implicit solvation models. For the explicit description of the solvent, molecular dynamics and Monte Carlo simulations in the isothermal-isobaric (NpT) ensemble combined with the free energy perturbation technique were performed to determine solvation free energies. Within the implicit solvation approach, the polarizable continuum model and the conductor-like screening model were applied. Combination of gas phase results with the results obtained from the different solvation models through an appropriate thermodynamic cycle allows estimation of complexation free energies, enthalpies, and the respective entropic contributions in solution. Owing to the strong solvation effects of water the cyclic acetic acid dimer is not stable in aqueous solution. In less polar solvents the double hydrogen bond structure of the acetic acid dimer remains stable. This finding is in agreement with previous theoretical and experimental results. A similar trend as for the acetic acid dimer is also observed for the acetamide complex. The methanol complex was found to be thermodynamically unstable in gas phase as well as in any of the three solvents. 2010 Wiley Periodicals, Inc.

  12. Development of On-Demand Non-Polar and Semi-Polar Bulk Gallium Nitride Materials for Next Generation Electronic and Optoelectrode Devices

    National Research Council Canada - National Science Library

    Fini, P

    2007-01-01

    ...) wafers that will act as seeds for subsequent GaN boule growth in Phase II. Inlustra developed non-polar a-plane and m-plane GaN films with smooth surfaces and minimal wafer bowing and cracking...

  13. Defensive Armor of Potato Tubers: Nonpolar Metabolite Profiling, Antioxidant Assessment, and Solid-State NMR Compositional Analysis of Suberin-Enriched Wound-Healing Tissues.

    Science.gov (United States)

    Dastmalchi, Keyvan; Kallash, Linda; Wang, Isabel; Phan, Van C; Huang, Wenlin; Serra, Olga; Stark, Ruth E

    2015-08-05

    The cultivation, storage, and distribution of potato tubers are compromised by mechanical damage and suboptimal healing. To investigate wound-healing progress in cultivars with contrasting russeting patterns, metabolite profiles reported previously for polar tissue extracts were complemented by GC/MS measurements for nonpolar extracts and quantitative (13)C NMR of interfacial solid suspensions. Potential marker compounds that distinguish cultivar type and wound-healing time point included fatty acids, fatty alcohols, alkanes, glyceryl esters, α,ω-fatty diacids, and hydroxyfatty acids. The abundant long-chain fatty acids in nonpolar extracts and solids from the smooth-skinned Yukon Gold cultivar suggested extensive suberin biopolymer formation; this hypothesis was supported by high proportions of arenes, alkenes, and carbonyl groups in the solid and among the polar markers. The absence of many potential marker classes in nonpolar Atlantic extracts and interfacial solids suggested a limited extent of suberization. Modest scavenging activities of all nonpolar extracts indicate that the majority of antioxidants produced in response to wounding are polar.

  14. Ab initio density functional theory study of non-polar (10-10), (11-20) and semipolar {20-21} GaN surfaces

    Czech Academy of Sciences Publication Activity Database

    Mutombo, Pingo; Romanyuk, Olexandr

    2014-01-01

    Roč. 115, č. 20 (2014), "203508-1"-"203508-5" ISSN 0021-8979 Grant - others:AVČR(CZ) M100101201 Institutional support: RVO:68378271 Keywords : non-polar GaN * semipolar GaN * surface reconstructions * DFT Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.183, year: 2014

  15. Intramolecular proton-transfer processes starting at higher excited states: a fluorescence study on 2-butylamino-6-methyl-4-nitropyridine N-oxide in nonpolar solutions

    NARCIS (Netherlands)

    de Klerk, J.S.; Szemik-Hojniak, A.; Ariese, F.; Gooijer, C.

    2007-01-01

    This article describes the exceptional photophysics of 2-butylamino-6- methyl-4-nitropyridine N-oxide (2B6M). It is known from the literature that this compound may undergo excited-state intra- or intermolecular protontransfer reactions. In nonpolar solvents, 2B6M exhibits an unusual fluorescence

  16. An on-line normal-phase high performance liquid chromatography method for the rapid detection of radical scavengers in non-polar food matrixes

    NARCIS (Netherlands)

    Zhang, Q.; Klift, van der E.J.C.; Janssen, H.G.; Beek, van T.A.

    2009-01-01

    An on-line method for the rapid pinpointing of radical scavengers in non-polar mixtures like vegetable oils was developed. To avoid problems with dissolving the sample, normal-phase chromatography on bare silica gel was used with mixtures of hexane and methyl tert-butyl ether as the eluent. The high

  17. The development and characterization of a primarily mineral calcium phosphate - poly(epsilon-caprolactone) biocomposite

    Science.gov (United States)

    Dunkley, Ian Robert

    Orthopaedic reconstruction often involves the surgical introduction of structural implants that provide for rigid fixation, skeletal stabilization, and bone integration. The high stresses incurred by these implanted devices have historically limited material choices to metallic and select polymeric formulations. While mechanical requirements are achieved, these non-degradable materials do not participate actively in the remodeling of the skeleton and present the possibility of long-term failure or rejection. This is particularly relevant in cervical fusion, an orthopaedic procedure to treat damaged, degenerative or diseased intervertebral discs. A significant improvement on the available synthetic bone replacement/regeneration options for implants to treat these conditions in the cervical spine may be achieved with the development of primarily mineral biocomposites comprised of a bioactive ceramic matrix reinforced with a biodegradable polymer. Such a biocomposite may be engineered to possess the clinically required mechanical properties of a particular application, while maintaining the ability to be remodeled completely by the body. A biocomposite of Si-doped calcium phosphate (Si-CaP) and poly(epsilon-caprolactone) (PCL) was developed for application as such a synthetic bone material for potential use as a fusion device in the cervical spine. In this thesis, a method by which high mineral content Si-CaP/PCL biocomposites with interpenetrating matrices of mineral and polymer phases may be prepared will be demonstrated, in addition to the effects of the various preparation parameters on the biocomposite density, porosity and mechanical properties. This new technique by which dense, primarily ceramic Si-CaP/PCL biocomposites were prepared, allowed for the incorporation of mineral contents ranging between 45-97vol%. Polymer infiltration, accomplished solely by passive capillary uptake over several days, was found to be capable of fully infiltrating the microporosity

  18. Floral biology of two Vanilloideae (Orchidaceae) primarily adapted to pollination by euglossine bees.

    Science.gov (United States)

    Pansarin, E R; Pansarin, L M

    2014-11-01

    Vanilloideae comprises 15 genera distributed worldwide, among which are Vanilla and Epistephium (tribe Vanilleae). Based on field and laboratory investigations, the pollination biology of V. dubia and E. sclerophyllum was analysed. The former was surveyed in a semi-deciduous mesophytic forest at the biological reserve of Serra do Japi and in a marshy forest at the city of Pradópolis, southeastern Brazil. The latter was examined in rocky outcrop vegetation in the Chapada Diamantina, northeastern Brazil. In the studied populations, the tubular flowers of V. dubia and E. sclerophyllum were pollinated by bees. Pollen was deposited on either their scutellum (V. dubia) or scutum (E. sclerophyllum). The mentum region of V. dubia is dry, whereas that of E. sclerophyllum presents a small quantity of dilute nectar. Flowers of E. sclerophyllum are scentless, while those of V. dubia are odoriferous. Although V. dubia is self-compatible, it needs a pollinator to produce fruit. In contrast, E. sclerophyllum sets fruit through spontaneous self-pollination, but biotic pollination also occurs. Both species are primarily adapted to pollination by euglossine bees. Pollination by Euglossina seems to have occurred at least twice during the evolution of Vanilleae. Furthermore, shifts between rewarding and reward-free flowers and between autogamous and allogamous species have been reported among vanillas. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  19. Perceptions of Mindfulness in a Low-income, Primarily African American Treatment-Seeking Sample.

    Science.gov (United States)

    Spears, Claire Adams; Houchins, Sean C; Bamatter, Wendy P; Barrueco, Sandra; Hoover, Diana Stewart; Perskaudas, Rokas

    2017-12-01

    Individuals with low socioeconomic status (SES) and members of racial/ethnic minority groups often experience profound disparities in mental health and physical well-being. Mindfulness-based interventions show promise for improving mood and health behaviors in higher-SES and non-Latino White populations. However, research is needed to explore what types of adaptations, if any, are needed to best support underserved populations. This study used qualitative methods to gain information about a) perceptions of mindfulness, b) experiences with meditation, c) barriers to practicing mindfulness, and d) recommendations for tailoring mindfulness-based interventions in a low-income, primarily African American treatment-seeking sample. Eight focus groups were conducted with 32 adults (16 men and 16 women) currently receiving services at a community mental health center. Most participants (91%) were African American. Focus group data were transcribed and analyzed using NVivo 10. A team of coders reviewed the transcripts to identify salient themes. Relevant themes included beliefs that mindfulness practice might improve mental health (e.g., managing stress and anger more effectively) and physical health (e.g., improving sleep and chronic pain, promoting healthier behaviors). Participants also discussed ways in which mindfulness might be consistent with, and even enhance, their religious and spiritual practices. Results could be helpful in tailoring mindfulness-based treatments to optimize feasibility and effectiveness for low-SES adults receiving mental health services.

  20. Time to Stop Telling Biophysics Students that Light Is Primarily a Wave.

    Science.gov (United States)

    Nelson, Philip C

    2018-02-27

    Standard pedagogy introduces optics as though it were a consequence of Maxwell's equations and only grudgingly admits, usually in a rushed aside, that light has a particulate character that can somehow be reconciled with the wave picture. Recent revolutionary advances in optical imaging, however, make this approach more and more unhelpful: How are we to describe two-photon imaging, FRET, localization microscopy, and a host of related techniques to students who think of light primarily as a wave? I was surprised to find that everything I wanted my biophysics students to know about light, including image formation, x-ray diffraction, and even Bessel beams, could be expressed as well (or better) from the quantum viewpoint pioneered by Richard Feynman. Even my undergraduate students grasp this viewpoint as well as (or better than) the traditional one, and by mid-semester they are already well positioned to integrate the latest advances into their understanding. Moreover, I have found that this approach clarifies my own understanding of new techniques. Copyright © 2018 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  1. Notionally steady background noise acts primarily as a modulation masker of speech.

    Science.gov (United States)

    Stone, Michael A; Füllgrabe, Christian; Moore, Brian C J

    2012-07-01

    Stone et al. [J. Acoust. Soc Am. 130, 2874-2881 (2011)], using vocoder processing, showed that the envelope modulations of a notionally steady noise were more effective than the envelope energy as a masker of speech. Here the same effect is demonstrated using non-vocoded signals. Speech was filtered into 28 channels. A masker centered on each channel was added to the channel signal at a target-to-background ratio of -5 or -10 dB. Maskers were sinusoids or noise bands with bandwidth 1/3 or 1 ERB(N) (ERB(N) being the bandwidth of "normal" auditory filters), synthesized with Gaussian (GN) or low-noise (LNN) statistics. To minimize peripheral interactions between maskers, odd-numbered channels were presented to one ear and even to the other. Speech intelligibility was assessed in the presence of each "steady" masker and that masker 100% sinusoidally amplitude modulated (SAM) at 8 Hz. Intelligibility decreased with increasing envelope fluctuation of the maskers. Masking release, the difference in intelligibility between the SAM and its "steady" counterpart, increased with bandwidth from near-zero to around 50 percentage points for the 1-ERB(N) GN. It is concluded that the sinusoidal and GN maskers behaved primarily as energetic and modulation maskers, respectively.

  2. Asthma prevalence and risk factor assessment of an underserved and primarily Latino child population in Colorado.

    Science.gov (United States)

    Clark, Maggie L; Reynolds, Stephen J; Hendrikson, Edward; Peel, Jennifer L

    2014-01-01

    Asthma is a substantialpublic health burden among children. Disease and risk-factor discrepancies have been identified among racial, ethnic, and socioeconomic groups. At a rural health clinic (Salud Family Health Center) with primarily underserved and Latino patients in Colorado, the authors evaluated 250 medical records and administered 57 parental surveys to describe this population with respect to asthma diagnosis, asthma-like symptoms, and environmental/occupational risk factors among children. Wheeze and asthma were indicated in 9.7% and 8.9% of medical records, respectively. Twenty parents (35.7%) reported in a questionnaire that their child had experienced wheezing or whistling in the chest. Parents reported that children play in farming fields (21.8%) and feed livestock/animals (10.9%). Additionally, 13.2% and 9.4% of children have a household member who works around livestock or around grain, feed, or dust, respectively. Information from the Salud population can be used to develop larger-scale research and public health initiatives to eliminate health and risk factor disparities among underserved children.

  3. Evolutionary Stable Strategy

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 9. Evolutionary Stable Strategy: Application of Nash Equilibrium in Biology. General ... Using some examples of classical games, we show how evolutionary game theory can help understand behavioural decisions of animals.

  4. The Stable Concordance Genus

    OpenAIRE

    Kearney, M. Kate

    2013-01-01

    The concordance genus of a knot is the least genus of any knot in its concordance class. Although difficult to compute, it is a useful invariant that highlights the distinction between the three-genus and four-genus. In this paper we define and discuss the stable concordance genus of a knot, which describes the behavior of the concordance genus under connected sum.

  5. Manifolds admitting stable forms

    Czech Academy of Sciences Publication Activity Database

    Le, Hong-Van; Panák, Martin; Vanžura, Jiří

    2008-01-01

    Roč. 49, č. 1 (2008), s. 101-11 ISSN 0010-2628 R&D Projects: GA ČR(CZ) GP201/05/P088 Institutional research plan: CEZ:AV0Z10190503 Keywords : stable forms * automorphism groups Subject RIV: BA - General Mathematics

  6. Stable isotope studies

    International Nuclear Information System (INIS)

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs

  7. Interactive Stable Ray Tracing

    DEFF Research Database (Denmark)

    Dal Corso, Alessandro; Salvi, Marco; Kolb, Craig

    2017-01-01

    Interactive ray tracing applications running on commodity hardware can suffer from objectionable temporal artifacts due to a low sample count. We introduce stable ray tracing, a technique that improves temporal stability without the over-blurring and ghosting artifacts typical of temporal post-pr...

  8. The stable subgroup graph

    Directory of Open Access Journals (Sweden)

    Behnaz Tolue

    2018-07-01

    Full Text Available In this paper we introduce stable subgroup graph associated to the group $G$. It is a graph with vertex set all subgroups of $G$ and two distinct subgroups $H_1$ and $H_2$ are adjacent if $St_{G}(H_1\\cap H_2\

  9. Influence of Nonpolar Substances on the Extraction Efficiency of Six Alkaloids in Zoagumhwan Investigated by Ultra Performance Liquid Chromatography and Photodiode Array Detection

    Directory of Open Access Journals (Sweden)

    Shijing Liu

    2012-11-01

    Full Text Available A reverse phase ultra performance liquid chromatography and photodiode array (UPLC-PDA detection method was established for the determination of six alkaloids in Zoagumhwan (ZGW, and further for investigating the influence of nonpolar substances on the extraction efficiency of these alkaloids. The method was based on a BEH C18 (50 mm × 2.1 mm, 1.7 μm column and mobile phase of aqueous phosphoric acid and acetonitrile including 0.05% buffer solution under gradient elution. ZGW samples of ZGW I, II, III and IV were obtained and prepared by pre-processing the crude materials of Coptidis rhizoma and Evodiae fructus using four technologies, namely direct water decoction, removal of nonpolar substances in Evodiae fructus by supercritical fluid extraction (SFE, removal of nonpolar substances in ZGW by SFE and removal of nonpolar substances in ZGW by steam distillation. The developed and validated UPLC-PDA method was precise, accurate and sensitive enough based on the facts that the six alkaloids showed good regression (r > 0.9998, the limit of detections and quantifications for six alkaloids were less than 28.8 and 94.5 ng/mL, respectively, and the recovery was in the range of 98.56%–103.24%. The sequence of the total contents of six alkaloids in these samples was ZGW II > ZGW IV > ZGW III > ZGW I. ZGW II, in which nonpolar substances, including essential oils, were firstly removed from Evodiae fructus by SFE, had the highest content of the total alkaloids, indicating that extraction efficiency of the total alkaloids could be remarkably increased after Evodiae fructus being extracted by SFE.

  10. Geometry of simple molecules: nonbonded interactions, not bonding orbitals, and primarily determine observed geometries.

    Science.gov (United States)

    See, R F; Dutoi, A D; McConnell, K W; Naylor, R M

    2001-03-28

    The forces responsible for the observed geometries of the YX(3) (Y = N or P; X = H, F, or Cl) molecules were studied through ab initio computations at the HF-SCF/6-31G level. The calculated molecular orbitals were grouped as contributing primarily to (a) the covalent bonds, (b) the terminal atom nonbonding electrons (for X = F or Cl), and (c) the central atom nonbonding electrons. This grouping was accomplished through 3-D plotting and an atomic population analysis of the molecular orbitals. The molecules were then moved through a X-Y-X angular range from 90 degrees to 119 degrees, in four or five degree increments. Single-point calculations were done at each increment, so as to quantify the energy changes in the molecular orbital groups as a function of geometry. These calculations show that the nonbonding electrons are much more sensitive to geometry change than are the bonding orbitals, particularly in the trihalide compounds. The molecular orbitals representing the nonbonding electrons on the terminal atoms (both valence and core electrons) contribute to the spreading forces, as they favor a wider X-Y-X angle. The contracting forces, which favor a smaller X-Y-X angle, consist of the orbitals comprising the nonbonding electrons on the central atom (again, both valence and core electrons). The observed geometry is seen as the balance point between these two sets of forces. A simple interaction-distance model of spreading and contracting forces supports this hypothesis. Highly linear trends are obtained for both the nitrogen trihalides (R(2) = 0.981) and phosphorus trihalides (R(2) = 0.992) when the opposing forces are plotted against each other. These results suggest that a revision of the popular conceptual models (hybridization and VSEPR) of molecular geometry might be appropriate.

  11. 49 CFR 178.337 - Specification MC 331; cargo tank motor vehicle primarily for transportation of compressed gases...

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Specification MC 331; cargo tank motor vehicle primarily for transportation of compressed gases as defined in subpart G of part 173 of this subchapter. 178... MC 331; cargo tank motor vehicle primarily for transportation of compressed gases as defined in...

  12. Polar and Nonpolar Gallium Nitride and Zinc Oxide based thin film heterostructures Integrated with Sapphire and Silicon

    Science.gov (United States)

    Gupta, Pranav

    This dissertation work explores the understanding of the relaxation and integration of polar and non-polar of GaN and ZnO thin films with Sapphire and silicon substrates. Strain management and epitaxial analysis has been performed on wurtzitic GaN(0001) thin films grown on c-Sapphire and wurtzitic non-polar a-plane GaN(11-20) thin films grown on r-plane Sapphire (10-12) by remote plasma atomic nitrogen source assisted UHV Pulsed Laser Deposition process. It has been established that high-quality 2-dimensional c-axis GaN(0001) nucleation layers can be grown on c-Sapphire by PLD process at growth temperatures as low as ˜650°C. Whereas the c-axis GaN on c-sapphire has biaxially negative misfit, the crystalline anisotropy of the a-plane GaN films on r-Sapphire results in compressive and tensile misfits in the two major orthogonal directions. The measured strains have been analyzed in detail by X-ray, Raman spectroscopy and TEM. Strain relaxation in GaN(0001)/Sapphire thin film heterostructure has been explained by the principle of domain matched epitaxial growth in large planar misfit system and has been demonstrated by TEM study. An attempt has been made to qualitatively understand the minimization of free energy of the system from the strain perspective. Analysis has been presented to quantify the strain components responsible for the compressive strain observed in the GaN(0001) thin films on c-axis Sapphire substrates. It was also observed that gallium rich deposition conditions in PLD process lead to smoother nucleation layers because of higher ad-atom mobility of gallium. We demonstrate near strain relaxed epitaxial (0001) GaN thin films grown on (111) Si substrates using TiN as intermediate buffer layer by remote nitrogen plasma assisted UHV pulsed laser deposition (PLD). Because of large misfits between the TiN/GaN and TiN/Si systems the TIN buffer layer growth occurs via nucleation of interfacial dislocations under domain matching epitaxy paradigm. X-ray and

  13. Stable isotope analysis

    International Nuclear Information System (INIS)

    Tibari, Elghali; Taous, Fouad; Marah, Hamid

    2014-01-01

    This report presents results related to stable isotopes analysis carried out at the CNESTEN DASTE in Rabat (Morocco), on behalf of Senegal. These analyzes cover 127 samples. These results demonstrate that Oxygen-18 and Deuterium in water analysis were performed by infrared Laser spectroscopy using a LGR / DLT-100 with Autosampler. Also, the results are expressed in δ values (‰) relative to V-SMOW to ± 0.3 ‰ for oxygen-18 and ± 1 ‰ for deuterium.

  14. Forensic Stable Isotope Biogeochemistry

    Science.gov (United States)

    Cerling, Thure E.; Barnette, Janet E.; Bowen, Gabriel J.; Chesson, Lesley A.; Ehleringer, James R.; Remien, Christopher H.; Shea, Patrick; Tipple, Brett J.; West, Jason B.

    2016-06-01

    Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements. Although this review is written in the context of US law, many of the considerations of scientific reproducibility and acceptance of relevant scientific data span other legal systems that might apply different legal principles and therefore reach different conclusions. Stable isotopes are used in legal situations for comparing samples for authenticity or evidentiary considerations, in understanding trade patterns of illegal materials, and in understanding the origins of unknown decedents. Isotope evidence is particularly useful when considered in the broad framework of physiochemical processes and in recognizing regional to global patterns found in many materials, including foods and food products, drugs, and humans. Stable isotopes considered in the larger spatial context add an important dimension to forensic science.

  15. Passerine Exposure to Primarily PCDFs and PCDDs in the River Floodplains Near Midland, Michigan, USA

    Science.gov (United States)

    Zwiernik, Matthew J.; Seston, Rita M.; Coefield, Sarah J.; Plautz, Stephanie C.; Tazelaar, Dustin L.; Shotwell, Melissa S.; Bradley, Patrick W.; Kay, Denise P.; Giesy, John P.

    2009-01-01

    House wren (Troglodytes aedon), tree swallow (Tachycineta bicolor), and eastern bluebird (Sialia sialis) tissues collected in study areas (SAs) downstream of Midland, Michigan (USA) contained concentrations of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) greater than in upstream reference areas (RAs) in the region. The sum of concentrations of PCDD/DFs (ΣPCDD/DFs) in eggs of house wrens and eastern bluebirds from SAs were 4- to 22-fold greater compared to those from RAs, whereas concentrations in tree swallow eggs were similar among areas. Mean concentrations of ΣPCDD/DFs and sum 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (ΣTEQsWHO-Avian), based on 1998 WHO avian toxic equivalency factors, in house wren and eastern bluebird eggs ranged from 860 (430) to 1500 (910) ng/kg wet weight (ww) and 470 (150) to 1100 (510) ng/kg ww, respectively, at the most contaminated study areas along the Tittabawassee River, whereas mean concentrations in tree swallow eggs ranged from 280 (100) to 760 (280) ng/kg ww among all locations. Concentrations of ΣPCDD/DFs in nestlings of all studied species at SAs were 3- to 50-fold greater compared to RAs. Mean house wren, tree swallow, and eastern bluebird nestling concentrations of ΣPCDD/DFs and ΣTEQsWHO-Avian ranged from 350 (140) to 610 (300) ng/kg ww, 360 (240) to 1100 (860) ng/kg ww, and 330 (100) to 1200 (690) ng/kg ww, respectively, at SAs along the Tittabawassee River. Concentrations of ΣTEQsWHO-Avian were positively correlated with ΣPCDD/DF concentrations in both eggs and nestlings of all species studied. Profiles of relative concentrations of individual congeners were dominated by furan congeners (69–84%), primarily 2,3,7,8-tetrachlorodibenzofuran and 2,3,4,7,8-pentachlorodibenzofuran, for all species at SAs on the Tittabawassee and Saginaw rivers but were dominated by dioxin congeners at upstream RAs. Electronic supplementary material The online version of this article (doi:10

  16. Suppression of progesterone synthesis in human trophoblast cells by fine particulate matter primarily derived from industry.

    Science.gov (United States)

    Wang, Cui; Yang, Jinhuan; Hao, Zhengliang; Gong, Chenxue; Tang, Lihua; Xu, Yingling; Lu, Dezhao; Li, Zhuoyu; Zhao, Meirong

    2017-12-01

    Epidemiological studies have exhibited a positive association between fine particulate matter (PM 2.5 ) exposure and adverse pregnancy outcome (APO). However, source-related effect and the potential mechanism have not been thoroughly elucidated in toxicology. In this study, PM 2.5 was collected during a severe winter haze episode in an energy-base city of China. We coupled this approach with the source appointment by applying the Lagrangian Integrated Trajectory and Concentration Weighted Trajectory model. We observed that the primary trajectory with high polluted air mass came from the northwest of the sampling site. Approximately 90% or more of PM 2.5 was derived from the industry at this haze period. Next, the sampled PM 2.5 was used to study the classical hormone synthesis pathway on trophoblast JEG-3 cells. PM 2.5 induced the secretion of human chorionic gonadotrophin (HCG) and the proliferation of JEG-3 cells at a noncytotoxic concentration. However, the synthesis of progesterone was significantly suppressed, even if both hCG and cyclic adenosine monophosphate (cAMP) were increased, suggesting that PM 2.5 may interfere the downstream of cAMP. As expected, the phosphorylated activity of protein kinase A (PKA) was attenuated. Subsequently, the downstream molecules of steroidogenesis, such as ferredoxin reductase (FDXR), CYP11A1 (encoded P450scc), and 3β-Hydroxysteroid dehydrogenase type 1 (3β-HSD1), were inhibited. Therefore, PM 2.5, primarily derived from industry, may directly inhibit the phosphorylation status of PKA in JEG-3 which, in turn, inhibited the proteins expression in progesterone-synthesis to suppress progesterone levels. Considering the pivotal role of progesterone in pregnancy maintenance, the mechanism on hormone synthesis may provide a better understanding for PM 2.5 -caused APO. Industry-emanated PM 2.5 , though not specific, could threaten the placenta, which needs to be verified by further epidemiological studies. Copyright © 2017

  17. Adsorption Study of a Water Molecule on Vacancy-Defected Nonpolar CdS Surfaces

    Science.gov (United States)

    2017-01-01

    A detailed understanding of the water–semiconductor interface is of major importance for elucidating the molecular interactions at the photocatalyst’s surface. Here, we studied the effect of vacancy defects on the adsorption of a water molecule on the (101̅0) and (112̅0) CdS surfaces, using spin-polarized density functional theory. We observed that the local spin polarization did not persist for most of the cationic vacancies on the surfaces, unlike in bulk, owing to surface reconstructions caused by displaced S atoms. This result suggests that cationic vacancies on these surfaces may not be the leading cause of the experimentally observed magnetism in CdS nanostructures. The surface vacancies are predominantly nonmagnetic except for one case, where a magnetic cationic vacancy is relatively stable due to constraints posed by the (101̅0) surface geometry. At this particular magnetic defect site, we found a very strong interaction with the H2O molecule leading to a case of chemisorption, where the local spin polarization vanishes concurrently. At the same defect site, adsorption of an O2 molecule was also simulated, and the results were found to be consistent with experimental electron paramagnetic resonance findings for powdered CdS. The anion vacancies on these surfaces were always found to be nonmagnetic and did not affect the water adsorption at these surfaces. PMID:28539988

  18. Analysis of survival for patients with chronic kidney disease primarily related to renal cancer surgery.

    Science.gov (United States)

    Wu, Jitao; Suk-Ouichai, Chalairat; Dong, Wen; Antonio, Elvis Caraballo; Derweesh, Ithaar H; Lane, Brian R; Demirjian, Sevag; Li, Jianbo; Campbell, Steven C

    2018-01-01

    To evaluate predictors of long-term survival for patients with chronic kidney disease primarily due to surgery (CKD-S). Patients with CKD-S have generally good survival that approximates patients who do not have CKD even after renal cancer surgery (RCS), yet there may be heterogeneity within this cohort. From 1997 to 2008, 4 246 patients underwent RCS at our centre. The median (interquartile range [IQR]) follow-up was 9.4 (7.3-11.0) years. New baseline glomerular filtration rate (GFR) was defined as highest GFR between nadir and 6 weeks after RCS. We retrospectively evaluated three cohorts: no-CKD (new baseline GFR of ≥60 mL/min/1.73 m 2 ); CKD-S (new baseline GFR of cancer-related survival (NRCRS) for the CKD-S cohort. Kaplan-Meier analysis assessed the longitudinal impact of new baseline GFR (45-60 mL/min/1.73 m 2 vs <45 mL/min/1.73 m 2 ) and Cox regression evaluated relative impact of preoperative GFR, new baseline GFR, and relevant demographics/comorbidities. Of the 4 246 patients who underwent RCS, 931 had CKD-S and 1 113 had CKD-M/S, whilst 2 202 had no-CKD even after RCS. Partial/radical nephrectomy (PN/RN) was performed in 54%/46% of the patients, respectively. For CKD-S, 641 patients had a new baseline GFR of 45-60 mL/min/1.73 m 2 and 290 had a new baseline GFR of <45 mL/min/1.73 m 2 . Kaplan-Meier analysis showed significantly reduced NRCRS for patients with CKD-S with a GFR of <45 mL/min/1.73 m 2 compared to those with no-CKD or CKD-S with a GFR of 45-60 mL/min/1.73 m 2 (both P ≤ 0.004), and competing risk analysis confirmed this (P < 0.001). Age, gender, heart disease, and new baseline GFR were all associated independently with NRCRS for patients with CKD-S (all P ≤ 0.02). Our data suggest that CKD-S is heterogeneous, and patients with a reduced new baseline GFR have compromised survival, particularly if <45 mL/min/1.73 m 2 . Our findings may have implications regarding choice of PN/RN in patients at risk of developing

  19. Strontium stable isotope behaviour accompanying basalt weathering

    Science.gov (United States)

    Burton, K. W.; Parkinson, I. J.; Gíslason, S. G. R.

    2016-12-01

    The strontium (Sr) stable isotope composition of rivers is strongly controlled by the balance of carbonate to silicate weathering (Krabbenhöft et al. 2010; Pearce et al. 2015). However, rivers draining silicate catchments possess distinctly heavier Sr stable isotope values than their bedrock compositions, pointing to significant fractionation during weathering. Some have argued for preferential release of heavy Sr from primary phases during chemical weathering, others for the formation of secondary weathering minerals that incorporate light isotopes. This study presents high-precision double-spike Sr stable isotope data for soils, rivers, ground waters and estuarine waters from Iceland, reflecting both natural weathering and societal impacts on those environments. The bedrock in Iceland is dominantly basaltic, d88/86Sr ≈ +0.27, extending to lighter values for rhyolites. Geothermal waters range from basaltic Sr stable compositions to those akin to seawater. Soil pore waters reflect a balance of input from primary mineral weathering, precipitation and litter recycling and removal into secondary phases and vegetation. Rivers and ground waters possess a wide range of d88/86Sr compositions from +0.101 to +0.858. Elemental and isotope data indicate that this fractionation primarily results from the formation or dissolution of secondary zeolite (d88/86Sr ≈ +0.10), but also carbonate (d88/86Sr ≈ +0.22) and sometimes anhydrite (d88/86Sr ≈ -0.73), driving the residual waters to heavier or lighter values, respectively. Estuarine waters largely reflect mixing with seawater, but are also be affected by adsorption onto particulates, again driving water to heavy values. Overall, these data indicate that the stability and nature of secondary weathering phases, exerts a strong control on the Sr stable isotope composition of silicate rivers. [1] Krabbenhöft et al. (2010) Geochim. Cosmochim. Acta 74, 4097-4109. [2] Pearce et al. (2015) Geochim. Cosmochim. Acta 157, 125-146.

  20. Tip-induced domain growth on the non-polar cuts of lithium niobate single-crystals

    Science.gov (United States)

    Alikin, D. O.; Ievlev, A. V.; Turygin, A. P.; Lobov, A. I.; Kalinin, S. V.; Shur, V. Ya.

    2015-05-01

    Currently, ferroelectric materials with designed domain structures are considered as a perspective material for new generation of photonic, data storage, and data processing devices. Application of external electric field is the most convenient way of the domain structure formation. Lots of papers are devoted to the investigation of domain kinetics on polar surface of crystals while the forward growth remains one of the most mysterious stages due to lack of experimental methods allowing to study it. Here, we performed tip-induced polarization reversal on X- and Y-non-polar cuts in single-crystal of congruent lithium niobate which allows us to study the forward growth with high spatial resolution. The revealed difference in the shape and length of domains induced on X- and Y-cuts is beyond previously developed theoretical approaches used for the theoretical consideration of the domains growth at non-polar ferroelectric surfaces. To explain experimental results, we used kinetic approach with anisotropy of screening efficiency along different crystallographic directions.

  1. Study of polar and nonpolar substituted benzenes and aromatic isomers on carbon-coated zirconia and alkyl bonded phases.

    Science.gov (United States)

    Jackson, Paul T; Carr, Peter W

    2002-06-07

    Retention factors of polar and non-polar mono- and di-substituted benzene derivatives were measured on carbon coated zirconia (C/ZrO2) and an alkyl modified silica using water-acetonitrile mobile phases. Published data on porous graphitic carbon phases (PGC) were used to facilitate comparisons between the two types of carbon media. This work showed that retention on both C/ZrO2 and PGC is much more sensitive to the solute polarizability, dipolarity, and shape than on aliphatic phases. For simple disubstituted benzenes there was no general clear cut advantage in terms of chromatographic selectivity to using a carbon-based phase over a bonded phase silica; however, the selectivities towards such isomers are quite different on the two types of media. In contradistinction to their effect on alkyl bonded phase retention, addition of a dipolar substituent and weak hydrogen bond acceptor to a benzene ring almost always increases the solute's retention on C/ZrO2 and PGC.

  2. Chemically assisted ion beam etching of laser diode facets on nonpolar and semipolar orientations of GaN

    Science.gov (United States)

    Kuritzky, L. Y.; Becerra, D. L.; Saud Abbas, A.; Nedy, J.; Nakamura, S.; DenBaars, S. P.; Cohen, D. A.

    2016-07-01

    We demonstrate a vertical (devices. The etch profiles were achieved with photoresist masks and optimized CAIBE chamber conditions including the platen tilt angle and Cl2 flow rate. Co-loaded studies showed similar etch rates of ˜60 nm min-1 for (20\\bar{2}\\bar{1}),(20\\bar{2}1), and m-plane orientations. The etched surfaces of LD facets on these orientations are chemically dissimilar (Ga-rich versus N-rich), but were visually indistinguishable, thus confirming the negligible orientation dependence of the etch. Continuous-wave blue LDs were fabricated on the semipolar (20\\bar{2}\\bar{1}) plane to compare CAIBE and reactive ion etch (RIE) facet processes. The CAIBE process resulted in LDs with lower threshold current densities due to reduced parasitic mirror loss compared with the RIE process. The LER, degree of verticality, and model of the 1D vertical laser mode were used to calculate a maximum uncoated facet reflection of 17% (94% of the nominal) for the CAIBE facet. The results demonstrate the suitability of CAIBE for forming high quality facets for high performance nonpolar and semipolar III-N LDs.

  3. Human Cytotoxic T Lymphocytes Form Dysfunctional Immune Synapses with B Cells Characterized by Non-Polarized Lytic Granule Release

    Directory of Open Access Journals (Sweden)

    Anna Kabanova

    2016-04-01

    Full Text Available Suppression of the cytotoxic T cell (CTL immune response has been proposed as one mechanism for immune evasion in cancer. In this study, we have explored the underlying basis for CTL suppression in the context of B cell malignancies. We document that human B cells have an intrinsic ability to resist killing by freshly isolated cytotoxic T cells (CTLs, but are susceptible to lysis by IL-2 activated CTL blasts and CTLs isolated from immunotherapy-treated patients with chronic lymphocytic leukemia (CLL. Impaired killing was associated with the formation of dysfunctional non-lytic immune synapses characterized by the presence of defective linker for activation of T cells (LAT signaling and non-polarized release of the lytic granules transported by ADP-ribosylation factor-like protein 8 (Arl8. We propose that non-lytic degranulation of CTLs are a key regulatory mechanism of evasion through which B cells may interfere with the formation of functional immune synapses by CTLs.

  4. Nodular melanoma: five consecutive cases in a general practice with polarized and non-polarized dermatoscopy and dermatopathology.

    Science.gov (United States)

    Rosendahl, Cliff; Hishon, Matthew; Cameron, Alan; Barksdale, Sarah; Weedon, David; Kittler, Harald

    2014-04-01

    The incidence of nodular melanoma (NM) has been consistently described as at least 10-15% of total melanomas for over 15 years despite advances in diagnostic algorithms and medical technology. NMs are strongly correlated with faster rates of growth and poorer prognosis and thus provide clinicians with a challenge for early recognition. To evaluate diagnostic clues of consecutive histopathologically proven NMs in one general practice with particular emphasis on dermatoscopic characteristics and compare this to the published literature. A retrospective observational study was performed of five consecutive histologically proven NM, from a total of 212 consecutive melanomas from a general practice in Brisbane, Queensland, Australia. Dermatoscopic images, both polarized and non-polarized, which appears to be a unique resource, and dermatopathologic slides were available for all lesions. All of the NMs in this series were pigmented although one was hypomelanotic. Two of them were symmetrical. The most highly sensitive clues to NM were gray or blue structures and polarizing-specific white lines. Due to the small number of NMs in this report no statistical significance can be attributed to the observational findings. THIS SMALL SERIES SUPPORTS WHAT IS ALREADY KNOWN: that a significant proportion of NMs may be dermatoscopically symmetrical but that known clues to melanoma are frequently present. Nodular lesions, pigmented or non-pigmented, should be excised to exclude NM if there is any clue to malignancy, regardless of symmetry, unless a confident specific benign diagnosis can be made.

  5. TEM studies of GaN layers grown in non-polar direction: Laterally overgrown and pendeo-epitaxial layers

    Science.gov (United States)

    Liliental-Weber, Z.

    2008-08-01

    The formation of structural defects in GaN grown in non-polar directions is reviewed based on transmission electron microscopy (TEM) studies. Stacking faults (SFs) formed on c-planes and also on prismatic planes bounded by partial dislocations, in addition to full dislocations, are major defects in these layers. Since c-planes are arranged perpendicular to the substrate, these defects propagate to the sample surface through the active areas of the devices and become detrimental for device applications. An established method to decrease the defect density is lateral epitaxial overgrowth (LEO) and pendeo-epitaxy. The measured density of SFs in the seed areas is ˜1.3×10 6 cm -1and in the 'wing' areas ˜1.2×10 4 cm -1; a decrease of almost of two orders of magnitude. For overgrown samples, two opposite wings grow in opposite polar directions: [0 0 0 1] (Ga-growth polarity) and [0 0 0 1] (N-growth polarity) confirmed by convergent beam electron diffraction. Ga-polar wings are wider and often have different height than those grown with N-polarity, therefore planarity of these layers and cracking at the meeting front of two wings often occur. It is shown that two-step growth using MOCVD leads to satisfactory layer planarity.

  6. Marginally Stable Nuclear Burning

    Science.gov (United States)

    Strohmayer, Tod E.; Altamirano, D.

    2012-01-01

    Thermonuclear X-ray bursts result from unstable nuclear burning of the material accreted on neutron stars in some low mass X-ray binaries (LMXBs). Theory predicts that close to the boundary of stability oscillatory burning can occur. This marginally stable regime has so far been identified in only a small number of sources. We present Rossi X-ray Timing Explorer (RXTE) observations of the bursting, high- inclination LMXB 4U 1323-619 that reveal for the first time in this source the signature of marginally stable burning. The source was observed during two successive RXTE orbits for approximately 5 ksec beginning at 10:14:01 UTC on March 28, 2011. Significant mHz quasi- periodic oscillations (QPO) at a frequency of 8.1 mHz are detected for approximately 1600 s from the beginning of the observation until the occurrence of a thermonuclear X-ray burst at 10:42:22 UTC. The mHz oscillations are not detected following the X-ray burst. The average fractional rms amplitude of the mHz QPOs is 6.4% (3 - 20 keV), and the amplitude increases to about 8% below 10 keV.This phenomenology is strikingly similar to that seen in the LMXB 4U 1636-53. Indeed, the frequency of the mHz QPOs in 4U 1323-619 prior to the X-ray burst is very similar to the transition frequency between mHz QPO and bursts found in 4U 1636-53 by Altamirano et al. (2008). These results strongly suggest that the observed QPOs in 4U 1323-619 are, like those in 4U 1636-53, due to marginally stable nuclear burning. We also explore the dependence of the energy spectrum on the oscillation phase, and we place the present observations within the context of the spectral evolution of the accretion-powered flux from the source.

  7. Nonpolar III-nitride vertical-cavity surface-emitting laser with a photoelectrochemically etched air-gap aperture

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, J. T., E-mail: jtleona01@gmail.com; Yonkee, B. P.; Cohen, D. A.; Megalini, L.; Speck, J. S. [Materials Department, University of California, Santa Barbara, California 93106 (United States); Lee, S. [Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106 (United States); DenBaars, S. P.; Nakamura, S. [Materials Department, University of California, Santa Barbara, California 93106 (United States); Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106 (United States)

    2016-01-18

    We demonstrate a III-nitride nonpolar vertical-cavity surface-emitting laser (VCSEL) with a photoelectrochemically (PEC) etched aperture. The PEC lateral undercut etch is used to selectively remove the multi-quantum well (MQW) region outside the aperture area, defined by an opaque metal mask. This PEC aperture (PECA) creates an air-gap in the passive area of the device, allowing one to achieve efficient electrical confinement within the aperture, while simultaneously achieving a large index contrast between core of the device (the MQW within the aperture) and the lateral cladding of the device (the air-gap formed by the PEC etch), leading to strong lateral confinement. Scanning electron microscopy and focused ion-beam analysis is used to investigate the precision of the PEC etch technique in defining the aperture. The fabricated single mode PECA VCSEL shows a threshold current density of ∼22 kA/cm{sup 2} (25 mA), with a peak output power of ∼180 μW, at an emission wavelength of 417 nm. The near-field emission profile shows a clearly defined single linearly polarized (LP) mode profile (LP{sub 12,1}), which is in contrast to the filamentary lasing that is often observed in III-nitride VCSELs. 2D mode profile simulations, carried out using COMSOL, give insight into the different mode profiles that one would expect to be displayed in such a device. The experimentally observed single mode operation is proposed to be predominantly a result of poor current spreading in the device. This non-uniform current spreading results in a higher injected current at the periphery of the aperture, which favors LP modes with high intensities near the edge of the aperture.

  8. Site-specific hydration dynamics in the nonpolar core of a molten globule by dynamic nuclear polarization of water.

    Science.gov (United States)

    Armstrong, Brandon D; Choi, Jennifer; López, Carlos; Wesener, Darryl A; Hubbell, Wayne; Cavagnero, Silvia; Han, Songi

    2011-04-20

    Water-protein interactions play a direct role in protein folding. The chain collapse that accompanies protein folding involves extrusion of water from the nonpolar core. For many proteins, including apomyoglobin (apoMb), hydrophobic interactions drive an initial collapse to an intermediate state before folding to the final structure. However, the debate continues as to whether the core of the collapsed intermediate state is hydrated and, if so, what the dynamic nature of this water is. A key challenge is that protein hydration dynamics is significantly heterogeneous, yet suitable experimental techniques for measuring hydration dynamics with site-specificity are lacking. Here, we introduce Overhauser dynamic nuclear polarization at 0.35 T via site-specific nitroxide spin labels as a unique tool to probe internal and surface protein hydration dynamics with site-specific resolution in the molten globular, native, and unfolded protein states. The (1)H NMR signal enhancement of water carries information about the local dynamics of the solvent within ∼10 Å of a spin label. EPR is used synergistically to gain insights on local polarity and mobility of the spin-labeled protein. Several buried and solvent-exposed sites of apoMb are examined, each bearing a covalently bound nitroxide spin label. We find that the nonpoloar core of the apoMb molten globule is hydrated with water bearing significant translational dynamics, only 4-6-fold slower than that of bulk water. The hydration dynamics of the native state is heterogeneous, while the acid-unfolded state bears fast-diffusing hydration water. This study provides a high-resolution glimpse at the folding-dependent nature of protein hydration dynamics.

  9. Antidiabetic, cytotoxic, antioxidant and antitrematodal medicinal efficacy of polar and non-polar phytochemicals of Balanites aegyptiaca Del.

    Directory of Open Access Journals (Sweden)

    Hanan Abd Al-Hay Saied Al-Ashaal

    2017-11-01

    Full Text Available Objective: To investigate the biological activities of polar and non-polar extracts of Balanites aegyptiaca fruits. Methods: Antihyperglycemic activity using alloxan induced diabetic rats was evaluated. In vitro cytotoxicity against human carcinoma cell lines activity in addition to antioxidant and antitrematodal effects were investigated. Phytochemicals were determined using chromatographic and spectral analyses including TLC, GC and LC/MS/MS methods. Results: The reduction in blood glucose level reached 64.13%, 69.07% and 77.01% for hexane, chloroform and methanol extract, respectively. Isolated organs and histopathological examination illustrated improvement in treated animal's pancreas which is the master gland in controlling glucose level. The highest in vitro free radical scavenging capacity was achieved by chloroform extract (75.72%. Meanwhile, hexane and methanol extracts exhibited 44.01% and 41.77% scavenging capacity, respectively. Cytotoxic activity against human carcinoma cell lines illustrated efficacious influence against brain, liver, lung, breast and lymphoblastic leukemia cell lines. Brain cell line was the most susceptible cell line by both chloroform and methanol extracts. In vitro antitrematodal effectiveness showed that 100% mortality of Schistosoma worms was induced at the 3rd and 5th days for methanol and chloroform extracts. Meanwhile, both extracts exhibited antifasciolosis activity with LC50 of 63.19 and 55.15 mg/L, respectively. Conclusions: The current results illustrated that Balanites aegyptiaca phytochemicals induced potent hypoglycemic activity and potent to moderate antioxidant and cytotoxic effects. Chloroform and methanol extracts were found to have antitrematodal efficacy against Schistosoma mansoni and Fasciola gigantica hepatic worms.

  10. Prognostic cell biological markers in cervical cancer patients primarily treated with (chemo)radiation : a systematic review

    NARCIS (Netherlands)

    Noordhuis, Maartje G; Eijsink, Jasper J H; Roossink, Frank; de Graeff, Pauline; Pras, Elisabeth; Schuuring, Ed; Wisman, G Bea A; de Bock, Geertruida H; van der Zee, Ate G J

    2011-01-01

    The aim of this study was to systematically review the prognostic and predictive significance of cell biological markers in cervical cancer patients primarily treated with (chemo)radiation. A PubMed, Embase, and Cochrane literature search was performed. Studies describing a relation between a cell

  11. Dynamical attraction to stable processes

    OpenAIRE

    Fisher, Albert M.; Talet, Marina

    2012-01-01

    We apply dynamical ideas within probability theory, proving an almost-sure invariance principle in log density for stable processes. The familiar scaling property (self-similarity) of the stable process has a stronger expression, that the scaling flow on Skorokhod path space is a Bernoulli flow. We prove that typical paths of a random walk with i.i.d. increments in the domain of attraction of a stable law can be paired with paths of a stable process so that, after applying a non-random regula...

  12. ELECTRONS IN NONPOLAR LIQUIDS.

    Energy Technology Data Exchange (ETDEWEB)

    HOLROYD,R.A.

    2002-10-22

    Excess electrons can be introduced into liquids by absorption of high energy radiation, by photoionization, or by photoinjection from metal surfaces. The electron's chemical and physical properties can then be measured, but this requires that the electrons remain free. That is, the liquid must be sufficiently free of electron attaching impurities for these studies. The drift mobility as well as other transport properties of the electron are discussed here as well as electron reactions, free-ion yields and energy levels, Ionization processes typically produce electrons with excess kinetic energy. In liquids during thermalization, where this excess energy is lost to bath molecules, the electrons travel some distance from their geminate positive ions. In general the electrons at this point are still within the coulombic field of their geminate ions and a large fraction of the electrons recombine. However, some electrons escape recombination and the yield that escapes to become free electrons and ions is termed G{sub fi}. Reported values of G{sub fi} for molecular liquids range from 0.05 to 1.1 per 100 eV of energy absorbed. The reasons for this 20-fold range of yields are discussed here.

  13. Thermal properties of some small peptides (N-acetyl-amino acid-N′-methylamides) with non-polar side groups

    International Nuclear Information System (INIS)

    Badea, Elena; Della Gatta, Giuseppe; Pałecz, Bartłomiej

    2014-01-01

    Highlights: • T fus and Δ fus H m of methylamides of N-acetyl substituted non-polar amino acids were measured. • T fus and Δ fus H m increased as a function of the molar mass of the alkyl side chains. • DL racemates showed T fus of about 40 °C lower than those of the corresponding pure L enantiomers. • Ideal solubility of solids at T = 298.15 K was estimated based on their T fus and Δ fus S m . - Abstract: Temperatures and molar enthalpies of fusion of a series of uncharged small peptides, namely the methylamides of N-acetyl substituted glycine, α-amino-butyric acid, alanine, valine, norvaline, leucine, isoleucine, norleucine, and proline, were measured by differential scanning calorimetry (d.s.c.), and molar entropies of fusion were derived. Both L- and DL-compunds were taken into account for the chiral molecules. No solid-to-solid transitions were detected from room temperature to fusion except for N-acetyl-N′-methyl alaninamide. Comparisons were made with the values for the N-acetyl amides of the corresponding amino acids previously reported. Both L enantiomers and DL racemates of α-aminobutyric acid, alanine, valine and isoleucine methylamides displayed temperatures of fusion sharply increasing as a function of molar mass, whereas much lower values, in countertendency with their molar mass increase, were found for proline and leucine methylamides. The racemic DL crystals showed temperatures of fusion of about 40 °C lower than those of the corresponding pure L enantiomers, except for proline and leucine derivatives. The enthalpies and entropies of fusion also varied as a function of molar mass following a similar trend with that of temperatures of fusion, except for alanine derivatives which showed lower values than expected. The values of ideal solubility of solids at T = 298.15 K were estimated based on their temperatures and molar entropies of fusion. Results were discussed with reference to the packing patterns based on hydrogen bonding and

  14. Using ZnO-Cr2O3-ZnO heterostructures to characterize polarization penetration depth through non-polar films.

    Science.gov (United States)

    Zhu, Xiaodong; Jhang, Jin-Hao; Zhou, Chao; Dagdeviren, Omur E; Chen, Zheng; Schwarz, Udo D; Altman, Eric I

    2017-12-13

    The ability to affect the surface properties of non-polar Cr 2 O 3 films through polar ZnO(0001) and (0001[combining macron]) supports was investigated by characterizing the polarity of ZnO films grown on top of the Cr 2 O 3 surfaces. The growth and geometric and electronic structures of the ZnO films were characterized with X-ray photoelectron spectroscopy, ultra-violet photoelectron spectroscopy, reflection high-energy electron diffraction, low-energy electron diffraction, and X-ray diffraction. The ZnO growth mode was Stranski-Krastanov, which can be attributed to the ZnO layers initially adopting a non-polar structure with a lower surface tension before transitioning to the polar bulk structure with a higher surface energy. A similar result has been reported for ZnO growth on α-Al 2 O 3 (0001), which is isostructural with Cr 2 O 3 . The polarity of the added ZnO layer was determined by examining the surface morphology following wet chemical etching with atomic force microscopy and by characterizing the surface reactivity via temperature-programmed desorption of alcohols, which strongly depends on the ZnO polarization direction. Consistent with prior work on ZnO growth on bulk Cr 2 O 3 (0001), both measurements indicate that thick Cr 2 O 3 layers support ZnO(0001[combining macron]) growth regardless of the underlying ZnO substrate polarization; however, the polarization direction of ZnO films grown on Cr 2 O 3 films less than three repeat units thick follows the direction of the underlying substrate polarization. These findings show that it is possible to manipulate the surface properties of non-polar materials with a polar substrate, but that the effect does not penetrate past just a couple of repeat units.

  15. Behavioral and electroencephalographic evaluation of the anticonvulsive activity of Moringa oleifera leaf non-polar extracts and one metabolite in PTZ-induced seizures.

    Science.gov (United States)

    González-Trujano, María Eva; Martínez-González, Claudia Lizbeth; Flores-Carrillo, Maricela; Luna-Nophal, Sara Ibeth; Contreras-Murillo, Gerardo; Magdaleno-Madrigal, Víctor Manuel

    2018-01-15

    Moringa oleifera Lamarck is a species that has long been used in high demand in folk medicine, including for the treatment of epilepsy. Nevertheless, scientific studies demonstrating its anticonvulsant properties and the nature of the bioactive constituents are lacking. The aim of this study was to evaluate the anticonvulsant activities of the Moringa oleifera leaves in non-polar vs. polar extracts using behavioral and electroencephalographic (EEG) analyses in rodents. First, PTZ (80 mg/kg, i.p.)-induced tonic-clonic seizures were assayed via a dose-response (100, 200 and 300 mg/kg, i.p.) evaluation in mice. Then, a dosage of the extracts (100 or 300 mg/kg) and one metabolite (30 mg/kg, i.p.) was selected to evaluate its effect on PTZ (35 mg/kg, i.p.)-induced EEG paroxystic activities in rats compared to the effects of ethosuximide (reference anticonvulsant drug, 100 mg/kg, i.p.). Latent onset of the first paroxystic spike, first seizure and frequency as well as seizure severity, were determined using Racine's scale. Moringa oleifera ethanol and hexane extracts produced a delay in the seizure latency in mice and rats; this effect was improved in the presence of the hexane extract containing the active metabolite hexadecanoic acid. The anticonvulsant effects were corroborated in the spectral analysis by the potency of the EEG due to a reduction in the spike frequency and amplitude, as well as in the duration and severity of the seizures. The effects of the hexane extract resembled those observed in the reference antiepileptic drug ethosuximide. Moringa oleifera leaves possess anticonvulsant activities due to the complementary of the non-polar and polar constituents. However, the non-polar constituents appear to exert an important influence via the partial participation of fatty acids, providing evidence of the effects of this plant in epilepsy therapy. Copyright © 2017. Published by Elsevier GmbH.

  16. Polar and non-polar organic aerosols from large-scale agricultural-waste burning emissions in Northern India: Implications to organic mass-to-organic carbon ratio.

    Science.gov (United States)

    Rajput, Prashant; Sarin, M M

    2014-05-01

    This study focuses on characteristics of organic aerosols (polar and non-polar) and total organic mass-to-organic carbon ratio (OM/OC) from post-harvest agricultural-waste (paddy- and wheat-residue) burning emissions in Northern India. Aerosol samples from an upwind location (Patiala: 30.2°N, 76.3°E) in the Indo-Gangetic Plain were analyzed for non-polar and polar fractions of organic carbon (OC1 and OC2) and their respective mass (OM1 and OM2). On average, polar organic aerosols (OM2) contribute nearly 85% of the total organic mass (OM) from the paddy- and wheat-residue burning emissions. The water-soluble-OC (WSOC) to OC2 ratio, within the analytical uncertainty, is close to 1 from both paddy- and wheat-residue burning emissions. However, temporal variability and relatively low WSOC/OC2 ratio (Av: 0.67±0.06) is attributed to high moisture content and poor combustion efficiency during paddy-residue burning, indicating significant contribution (∼30%) of aromatic carbon to OC2. The OM/OC ratio for non-polar (OM1/OC1∼1.2) and polar organic aerosols (OM2/OC2∼2.2), hitherto unknown for open agricultural-waste burning emissions, is documented in this study. The total OM/OC ratio is nearly identical, 1.9±0.2 and 1.8±0.2, from paddy- and wheat-residue burning emissions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. X-ray and CT signs of connective tissue dysplasia in patients with primarily diagnosed infiltrative pulmonary tuberculosis

    International Nuclear Information System (INIS)

    Sukhanova, L.A.; Sharmazanova, O.P.

    2009-01-01

    The x-ray signs of connective tissue systemic dysplasia (CTSD) in patients with primarily diagnosed pulmonary tuberculosis was investigated. Fifty-four patients (28 med and 26 women aged 18-70) with primarily diagnosed infiltrative pulmonary tuberculosis underwent x-ray study. In patients with infiltration pulmonary tuberculosis CTSD in the lungs manifests by their diminishing, deformity of the lung pattern, high position of the diaphragm cupola, mediastinum shift to the side of the pathology, which is better seen on CT. The degree of CTSD x-ray signs in the lungs depends on the number of phenotypical signs that is the degree of the disease manifestation. CT allows more accurate determining of the signs of connective tissue dysplasia in which tuberculosis develops

  18. Application of enriched stable isotopes as tracers in biological systems

    DEFF Research Database (Denmark)

    Stürup, Stefan; Hansen, Helle Rüsz; Gammelgaard, Bente

    2008-01-01

    The application of enriched stable isotopes of minerals and trace elements as tracers in biological systems is a rapidly growing research field that benefits from the many new developments in inorganic mass spectrometric instrumentation, primarily within inductively coupled plasma mass spectrometry...... (ICP-MS) instrumentation, such as reaction/collision cell ICP-MS and multicollector ICP-MS with improved isotope ratio measurement and interference removal capabilities. Adaptation and refinement of radioisotope tracer experiment methodologies for enriched stable isotope experiments......, and the development of new methodologies coupled with more advanced compartmental and mathematical models for the distribution of elements in living organisms has enabled a broader use of enriched stable isotope experiments in the biological sciences. This review discusses the current and future uses of enriched...

  19. Assessment of Vegetation Variation on Primarily Creation Zones of the Dust Storms Around the Euphrates Using Remote Sensing Images

    Directory of Open Access Journals (Sweden)

    Jamil Amanollahi

    2012-06-01

    Full Text Available Recently, period frequency and effect domain of the dust storms that enter Iran from Iraq have increased. In this study, in addition to detecting the creation zones of the dust storms, the effect of vegetation cover variation on their creation was investigated using remote sensing. Moderate resolution image Spectroradiometer (MODIS and Landsat Thematic Mapper (TM5 have been utilized to identify the primarily creation zones of the dust storms and to assess the vegetation cover variation, respectively. Vegetation cover variation was studied using Normalized Differences Vegetation Index (NDVI obtained from band 3 and band 4 of the Landsate satellite. The results showed that the surrounding area of the Euphrates in Syria, the desert in the vicinity of this river in Iraq, including the deserts of Alanbar Province, and the north deserts of Saudi Arabia are the primarily creation zones of the dust storms entering west and south west of Iran. The results of NDVI showed that excluding the deserts in the border of Syria and Iraq, the area with very weak vegetation cover have increased between 2.44% and 20.65% from 1991 to 2009. In the meanwhile, the retention pound surface areas in the south deserts of Syria as well as the deserts in its border with Iraq have decreased 6320 and 4397 hectares, respectively. As it can be concluded from the findings, one of the main environmental parameters initiating these dust storms is the decrease in the vegetation cover in their primarily creation zones.

  20. The Formation of Self-Organized Domain Structures at Non-Polar Cuts of Lithium Niobate as a Result of Local Switching by an SPM Tip

    Directory of Open Access Journals (Sweden)

    Anton Turygin

    2017-09-01

    Full Text Available We have studied experimentally the interaction of isolated needle-like domains created in an array via local switching using a biased scanning probe microscope (SPM tip and visualized via piezoelectric force microscopy (PFM at the non-polar cuts of MgO-doped lithium niobate (MgOLN crystals. It has been found that the domain interaction leads to the intermittent quasiperiodic and chaotic behavior of the domain length in the array in a manner similar to that of polar cuts, but with greater spacing between the points of bias application and voltage amplitudes. It has also been found that the polarization reversal at the non-polar cuts and domain interaction significantly depend on humidity. The spatial distribution of the surface potential measured by Kelvin probe force microscopy in the vicinity of the charged domain walls revealed the decrease of the domain length as a result of the partial backswitching after pulse termination. The phase diagram of switching behavior as a function of tip voltage and spacing between the points of bias application has been plotted. The obtained results provide new insight into the problem of the domain interaction during forward growth and can provide a basis for useful application in nanodomain engineering and development of non-linear optical frequency converters, data storage, and computing devices.

  1. Atmospheric pressure chemical ionization studies of non-polar isomeric hydrocarbons using ion mobility spectrometry and mass spectrometry with different ionization techniques

    Science.gov (United States)

    Borsdorf, H.; Nazarov, E. G.; Eiceman, G. A.

    2002-01-01

    The ionization pathways were determined for sets of isomeric non-polar hydrocarbons (structural isomers, cis/trans isomers) using ion mobility spectrometry and mass spectrometry with different techniques of atmospheric pressure chemical ionization to assess the influence of structural features on ion formation. Depending on the structural features, different ions were observed using mass spectrometry. Unsaturated hydrocarbons formed mostly [M - 1]+ and [(M - 1)2H]+ ions while mainly [M - 3]+ and [(M - 3)H2O]+ ions were found for saturated cis/trans isomers using photoionization and 63Ni ionization. These ionization methods and corona discharge ionization were used for ion mobility measurements of these compounds. Different ions were detected for compounds with different structural features. 63Ni ionization and photoionization provide comparable ions for every set of isomers. The product ions formed can be clearly attributed to the structures identified. However, differences in relative abundance of product ions were found. Although corona discharge ionization permits the most sensitive detection of non-polar hydrocarbons, the spectra detected are complex and differ from those obtained with 63Ni ionization and photoionization. c. 2002 American Society for Mass Spectrometry.

  2. Interfacial B-site atomic configuration in polar (111) and non-polar (001) SrIrO3/SrTiO3 heterostructures

    Science.gov (United States)

    Anderson, T. J.; Zhou, H.; Xie, L.; Podkaminer, J. P.; Patzner, J. J.; Ryu, S.; Pan, X. Q.; Eom, C. B.

    2017-09-01

    The precise control of interfacial atomic arrangement in ABO3 perovskite heterostructures is paramount, particularly in cases where the subsequent electronic properties of the material exhibit geometrical preferences along polar crystallographic directions that feature inevitably complex surface reconstructions. Here, we present the B-site interfacial structure in polar (111) and non-polar (001) SrIrO3/SrTiO3 interfaces. The heterostructures were examined using scanning transmission electron microscopy and synchrotron-based coherent Bragg rod analysis. Our results reveal the preference of B-site intermixing across the (111) interface due to the polarity-compensated SrTiO3 substrate surface prior to growth. By comparison, the intermixing at the non-polar (001) interface is negligible. This finding suggests that the intermixing may be necessary to mitigate epitaxy along heavily reconstructed and non-stoichiometric (111) perovskite surfaces. Furthermore, this preferential B-site configuration could allow the geometric design of the interfacial perovskite structure and chemistry to selectively engineer the correlated electronic states of the B-site d-orbital.

  3. Hexagonal SiC with spatially separated active sites on polar and nonpolar facets achieving enhanced hydrogen production from photocatalytic water reduction.

    Science.gov (United States)

    Wang, Da; Liu, Ning; Guo, Zhongnan; Wang, Wenjun; Guo, Liwei; Yuan, Wenxia; Chen, Xiaolong

    2018-02-14

    Sufficient spatial separation of photo-generated electrons and holes plays a significant role in affecting the efficiency for solar energy conversion. Non-equivalent facets of a catalyst are known to possess different charge distribution properties. Here, we report that hexagonal 6H-SiC, a metal-free, environmentally friendly, polar semiconductor, exhibits different charge distribution and photocatalytic properties on naturally occurring Si-{0001} and {10-10} facets. Very strong selectivity of metals in situ photodeposition occurs in these two facets, demonstrating that the photo-excited electrons are assembled only on polar Si-{0001} facets while the holes are assembled on non-polar {10-10} facets. Consequently, reduction reactions occur only on the Si-{0001} facets with noble metals, and meantime oxidation occurs only in {10-10} with metal oxide. We show that the activity of photocatalytic water splitting is significantly enhanced by this kind of selective depositions resulting from the charge spatial separation. The underlying mechanism is investigated in terms of experimental evidence and first principles calculations. Our results demonstrate that the utilization of facets with opposite catalytic characteristics could be a feasible means to enhance the photocatalytic performance in diverse semiconducting materials. This is, in particular, of interest for polar semiconductors, as their particles always naturally occur in both polar facets and non-polar ones without needing facet engineering.

  4. Growth of non-polar (11-20 InGaN quantum dots by metal organic vapour phase epitaxy using a two temperature method

    Directory of Open Access Journals (Sweden)

    J. T. Griffiths

    2014-12-01

    Full Text Available Non-polar (11-20 InGaN quantum dots (QDs were grown by metal organic vapour phase epitaxy. An InGaN epilayer was grown and subjected to a temperature ramp in a nitrogen and ammonia environment before the growth of the GaN capping layer. Uncapped structures with and without the temperature ramp were grown for reference and imaged by atomic force microscopy. Micro-photoluminescence studies reveal the presence of resolution limited peaks with a linewidth of less than ∼500 μeV at 4.2 K. This linewidth is significantly narrower than that of non-polar InGaN quantum dots grown by alternate methods and may be indicative of reduced spectral diffusion. Time resolved photoluminescence studies reveal a mono-exponential exciton decay with a lifetime of 533 ps at 2.70 eV. The excitonic lifetime is more than an order of magnitude shorter than that for previously studied polar quantum dots and suggests the suppression of the internal electric field. Cathodoluminescence studies show the spatial distribution of the quantum dots and resolution limited spectral peaks at 18 K.

  5. Interfacial B-site atomic configuration in polar (111 and non-polar (001 SrIrO3/SrTiO3 heterostructures

    Directory of Open Access Journals (Sweden)

    T. J. Anderson

    2017-09-01

    Full Text Available The precise control of interfacial atomic arrangement in ABO3 perovskite heterostructures is paramount, particularly in cases where the subsequent electronic properties of the material exhibit geometrical preferences along polar crystallographic directions that feature inevitably complex surface reconstructions. Here, we present the B-site interfacial structure in polar (111 and non-polar (001 SrIrO3/SrTiO3 interfaces. The heterostructures were examined using scanning transmission electron microscopy and synchrotron-based coherent Bragg rod analysis. Our results reveal the preference of B-site intermixing across the (111 interface due to the polarity-compensated SrTiO3 substrate surface prior to growth. By comparison, the intermixing at the non-polar (001 interface is negligible. This finding suggests that the intermixing may be necessary to mitigate epitaxy along heavily reconstructed and non-stoichiometric (111 perovskite surfaces. Furthermore, this preferential B-site configuration could allow the geometric design of the interfacial perovskite structure and chemistry to selectively engineer the correlated electronic states of the B-site d-orbital.

  6. Analysis and study of the distribution of polar and non-polar pesticides in wastewater effluents from modern and conventional treatments.

    Science.gov (United States)

    Barco-Bonilla, Nieves; Romero-González, Roberto; Plaza-Bolaños, Patricia; Garrido Frenich, Antonia; Martínez Vidal, José Luis

    2010-12-10

    The analysis of a wide range of pesticides in wastewaters (WWs) undergoing different treatments (both modern and conventional) has been studied. The need for optimizing specific extraction methods for each WW effluent based on their physico-chemical characteristics has been considered. A distribution study was performed to establish if the filtration step before extraction is a correct procedure since pesticides can be more prone to be in the aqueous or the solid phase, depending on their hydrophobicity. This evaluation demonstrated that pesticides are distributed between the aqueous phase and the suspended particulate matter (SPM; e.g. pyrethroids are only found in the SPM). The proposed methodologies involved the determination of 39 polar and 139 non-polar pesticides using solid-phase extraction (SPE) and pressurized-liquid extraction (PLE) for the extraction of the aqueous phase and the SPM, respectively. Ultra high pressure liquid chromatography and gas chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS, GC-MS/MS) were used in the determination stage. WW samples from four different technologies were evaluated: membrane bioreactor, extended aeration, maturation pond and anaerobic pond. Validation data for the four effluents studied were generated, obtaining adequate precision values (estimated as % relative standard deviation, RSD) in almost all cases (treatment plant, detecting non-polar and polar pesticides at concentrations in the range 0.02-1.94μgL(-1) and 0.02-0.33μgL(-1), respectively. Copyright © 2010 Elsevier B.V. All rights reserved.

  7. Shelf-Stable Food Safety

    Science.gov (United States)

    ... is an MRE? Is an MRE shelf stable? What foods are packaged in retort packages? What is aseptic ... type of package is used for aseptic processing? What foods are packaged in aseptic packages? Can I microwave ...

  8. Pharmaceuticals labelled with stable isotopes

    International Nuclear Information System (INIS)

    Krumbiegel, P.

    1986-11-01

    The relatively new field of pharmaceuticals labelled with stable isotopes is reviewed. Scientific, juridical, and ethical questions are discussed concerning the application of these pharmaceuticals in human medicine. 13 C, 15 N, and 2 H are the stable isotopes mainly utilized in metabolic function tests. Methodical contributions are given to the application of 2 H, 13 C, and 15 N pharmaceuticals showing new aspects and different states of development in the field under discussion. (author)

  9. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1984-03-01

    This report contains a listing of electromagnetically separated stable isotopes which are available at the Oak Ridge National Laboratory for distribution for nondestructive research use on a loan basis. This inventory includes all samples of stable isotopes in the Research Materials Collection and does not designate whether a sample is out on loan or is in reprocessing. For some of the high abundance naturally occurring isotopes, larger amounts can be made available; for example, Ca-40 and Fe-56

  10. Stable Boundary Layer Education (STABLE) Final Campaign Summary

    Energy Technology Data Exchange (ETDEWEB)

    Turner, David D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-01

    The properties of, and the processes that occur in, the nocturnal stable boundary layer are not well understood, making it difficult to represent adequately in numerical models. The nocturnal boundary layer often is characterized by a temperature inversion and, in the Southern Great Plains region, a low-level jet. To advance our understanding of the nocturnal stable boundary layer, high temporal and vertical resolution data on the temperature and wind properties are needed, along with both large-eddy simulation and cloud-resolving modeling.

  11. One-pot synthesis of stable colloidal solutions of MFe2O4 nanoparticles using oleylamine as solvent and stabilizer

    International Nuclear Information System (INIS)

    Pérez-Mirabet, Leonardo; Solano, Eduardo; Martínez-Julián, Fernando; Guzmán, Roger; Arbiol, Jordi; Puig, Teresa; Obradors, Xavier; Pomar, Alberto; Yáñez, Ramón; Ros, Josep; Ricart, Susagna

    2013-01-01

    Highlights: ► One-pot synthesis of ferrite magnetic nanoparticles ( 3 and M(acac) 2 (M = Co, Mn, Cu and Zn) in oleylamine, which also acts as a capping ligand, by producing stable colloidal dispersions of nanoparticles in non-polar solvents. The properties of the nanoparticles have been studied via different techniques, such as transmission electron microscopy, which shows that nanoparticles are monocrystallines and a narrow dispersion in size; magnetic analyses have demonstrated that the resulting ferrite nanoparticles show high saturation values and superparamagnetic behavior at room temperature; X-ray diffraction has also been performed, and it confirms that the synthesized nanoparticles have a spinel structure. Complementarily, ligand exchange has been also carried out in order to produce dispersions of the synthesized nanoparticles in polar media

  12. Interdomain Linker Determines Primarily the Structural Stability of Dystrophin and Utrophin Tandem Calponin-Homology Domains Rather than Their Actin-Binding Affinity.

    Science.gov (United States)

    Bandi, Swati; Singh, Surinder M; Mallela, Krishna M G

    2015-09-08

    Tandem calponin-homology (CH) domains are the most common actin-binding domains in proteins. However, structural principles underlying their function are poorly understood. These tandem domains exist in multiple conformations with varying degrees of inter-CH-domain interactions. Dystrophin and utrophin tandem CH domains share high sequence similarity (∼82%), yet differ in their structural stability and actin-binding affinity. We examined whether the conformational differences between the two tandem CH domains can explain differences in their stability and actin binding. Dystrophin tandem CH domain is more stable by ∼4 kcal/mol than that of utrophin. Individual CH domains of dystrophin and utrophin have identical structures but differ in their relative orientation around the interdomain linker. We swapped the linkers between dystrophin and utrophin tandem CH domains. Dystrophin tandem CH domain with utrophin linker (DUL) has similar stability as that of utrophin tandem CH domain. Utrophin tandem CH domain with dystrophin linker (UDL) has similar stability as that of dystrophin tandem CH domain. Dystrophin tandem CH domain binds to F-actin ∼30 times weaker than that of utrophin. After linker swapping, DUL has twice the binding affinity as that of dystrophin tandem CH domain. Similarly, UDL has half the binding affinity as that of utrophin tandem CH domain. However, changes in binding free energies due to linker swapping are much lower by an order of magnitude compared to the corresponding changes in unfolding free energies. These results indicate that the linker region determines primarily the structural stability of tandem CH domains rather than their actin-binding affinity.

  13. Multi-Province Listeriosis Outbreak Linked to Contaminated Deli Meat Consumed Primarily in Institutional Settings, Canada, 2008.

    Science.gov (United States)

    Currie, Andrea; Farber, Jeffrey M; Nadon, Céline; Sharma, Davendra; Whitfield, Yvonne; Gaulin, Colette; Galanis, Eleni; Bekal, Sadjia; Flint, James; Tschetter, Lorelee; Pagotto, Franco; Lee, Brenda; Jamieson, Fred; Badiani, Tina; MacDonald, Diane; Ellis, Andrea; May-Hadford, Jennifer; McCormick, Rachel; Savelli, Carmen; Middleton, Dean; Allen, Vanessa; Tremblay, Francois-William; MacDougall, Laura; Hoang, Linda; Shyng, Sion; Everett, Doug; Chui, Linda; Louie, Marie; Bangura, Helen; Levett, Paul N; Wilkinson, Krista; Wylie, John; Reid, Janet; Major, Brian; Engel, Dave; Douey, Donna; Huszczynski, George; Di Lecci, Joe; Strazds, Judy; Rousseau, Josée; Ma, Kenneth; Isaac, Leah; Sierpinska, Urszula

    2015-08-01

    A multi-province outbreak of listeriosis occurred in Canada from June to November 2008. Fifty-seven persons were infected with 1 of 3 similar outbreak strains defined by pulsed-field gel electrophoresis, and 24 (42%) individuals died. Forty-one (72%) of 57 individuals were residents of long-term care facilities or hospital inpatients during their exposure period. Descriptive epidemiology, product traceback, and detection of the outbreak strains of Listeria monocytogenes in food samples and the plant environment confirmed delicatessen meat manufactured by one establishment and purchased primarily by institutions was the source of the outbreak. The food safety investigation identified a plant environment conducive to the introduction and proliferation of L. monocytogenes and persistently contaminated with Listeria spp. This outbreak demonstrated the need for improved listeriosis surveillance, strict control of L. monocytogenes in establishments producing ready-to-eat foods, and advice to vulnerable populations and institutions serving these populations regarding which high-risk foods to avoid.

  14. Accumulation of a poly(hydroxyalkanoate) copolymer containing primarily 3-hydroxyvalerate from simple carbohydrate substrates by Rhodococcus sp. NCIMB 40126.

    Science.gov (United States)

    Haywood, G W; Anderson, A J; Williams, D R; Dawes, E A; Ewing, D F

    1991-04-01

    A number of taxonomically-related bacteria have been identified which accumulate poly(hydroxyalkanoate) (PHA) copolymers containing primarily 3-hydroxyvalerate (3HV) monomer units from a range of unrelated single carbon sources. One of these, Rhodococcus sp. NCIMB 40126, was further investigated and shown to produce a copolymer containing 75 mol% 3HV and 25 mol% 3-hydroxybutyrate (3HB) from glucose as sole carbon source. Polyesters containing both 3HV and 3HB monomer units, together with 4-hydroxybutyrate (4HB), 5-hydroxyvalerate (5HV) or 3-hydroxyhexanoate (3HHx), were also produced by this organism from certain accumulation substrates. With valeric acid as substrate, almost pure (99 mol% 3HV) poly(3-hydroxyvalerate) was produced. N.m.r. analysis confirmed the composition of these polyesters. The thermal properties and molecular weight of the copolymer produced from glucose were comparable to those of PHB produced by Alcaligenes eutrophus.

  15. Y-chromosomal analysis of Greek Cypriots reveals a primarily common pre-Ottoman paternal ancestry with Turkish Cypriots

    Science.gov (United States)

    Fernández-Domínguez, Eva; Bertoncini, Stefania; Chimonas, Marios; Christofi, Vasilis; King, Jonathan; Budowle, Bruce; Manoli, Panayiotis

    2017-01-01

    Genetics can provide invaluable information on the ancestry of the current inhabitants of Cyprus. A Y-chromosome analysis was performed to (i) determine paternal ancestry among the Greek Cypriot (GCy) community in the context of the Central and Eastern Mediterranean and the Near East; and (ii) identify genetic similarities and differences between Greek Cypriots (GCy) and Turkish Cypriots (TCy). Our haplotype-based analysis has revealed that GCy and TCy patrilineages derive primarily from a single gene pool and show very close genetic affinity (low genetic differentiation) to Calabrian Italian and Lebanese patrilineages. In terms of more recent (past millennium) ancestry, as indicated by Y-haplotype sharing, GCy and TCy share much more haplotypes between them than with any surrounding population (7–8% of total haplotypes shared), while TCy also share around 3% of haplotypes with mainland Turks, and to a lesser extent with North Africans. In terms of Y-haplogroup frequencies, again GCy and TCy show very similar distributions, with the predominant haplogroups in both being J2a-M410, E-M78, and G2-P287. Overall, GCy also have a similar Y-haplogroup distribution to non-Turkic Anatolian and Southwest Caucasian populations, as well as Cretan Greeks. TCy show a slight shift towards Turkish populations, due to the presence of Eastern Eurasian (some of which of possible Ottoman origin) Y-haplogroups. Overall, the Y-chromosome analysis performed, using both Y-STR haplotype and binary Y-haplogroup data puts Cypriot in the middle of a genetic continuum stretching from the Levant to Southeast Europe and reveals that despite some differences in haplotype sharing and haplogroup structure, Greek Cypriots and Turkish Cypriots share primarily a common pre-Ottoman paternal ancestry. PMID:28622394

  16. Healthy younger and older adults control foot placement to avoid small obstacles during gait primarily by modulating step width

    Directory of Open Access Journals (Sweden)

    Schulz Brian W

    2012-10-01

    Full Text Available Abstract Background Falls are a significant problem in the older population. Most falls occur during gait, which is primarily regulated by foot placement. Variability of foot placement has been associated with falls, but these associations are inconsistent and generally for smooth, level flooring. This study investigates the control of foot placement and the associated gait variability in younger and older men and women (N=7/group, total N=28 while walking at three different speeds (slow, preferred, and fast across a control surface with no obstacles and surfaces with multiple (64 small (10cm long ×13mm high visible and hidden obstacles. Results Minimum obstacle distance between the shoe and nearest obstacle during each footfall was greater on the visible obstacles surface for older subjects because some of them chose to actively avoid obstacles. This obstacle avoidance strategy was implemented primarily by modulating step width and to a lesser extent step length as indicated by linear regressions of step width and length variability on minimum obstacle distance. Mean gait speed, step length, step width, and step time did not significantly differ by subject group, flooring surface, or obstacle avoidance strategy. Conclusions Some healthy older subjects choose to actively avoid small obstacles that do not substantially perturb their gait by modulating step width and, to a lesser extent, step length. It is not clear if this obstacle avoidance strategy is appropriate and beneficial or overcautious and maladaptive, as it results in fewer obstacles encountered at a consequence of a less efficient gait pattern that has been shown to indicate increased fall risk. Further research is needed on the appropriateness of strategy selection when the environmental demands and/or task requirements have multiple possible completion strategies with conflicting objectives (i.e. perceived safety vs. efficiency.

  17. Development and Sensitivity Analysis of a Frost Risk model based primarily on freely distributed Earth Observation data

    Science.gov (United States)

    Louka, Panagiota; Petropoulos, George; Papanikolaou, Ioannis

    2015-04-01

    The ability to map the spatiotemporal distribution of extreme climatic conditions, such as frost, is a significant tool in successful agricultural management and decision making. Nowadays, with the development of Earth Observation (EO) technology, it is possible to obtain accurately, timely and in a cost-effective way information on the spatiotemporal distribution of frost conditions, particularly over large and otherwise inaccessible areas. The present study aimed at developing and evaluating a frost risk prediction model, exploiting primarily EO data from MODIS and ASTER sensors and ancillary ground observation data. For the evaluation of our model, a region in north-western Greece was selected as test site and a detailed sensitivity analysis was implemented. The agreement between the model predictions and the observed (remotely sensed) frost frequency obtained by MODIS sensor was evaluated thoroughly. Also, detailed comparisons of the model predictions were performed against reference frost ground observations acquired from the Greek Agricultural Insurance Organization (ELGA) over a period of 10-years (2000-2010). Overall, results evidenced the ability of the model to produce reasonably well the frost conditions, following largely explainable patterns in respect to the study site and local weather conditions characteristics. Implementation of our proposed frost risk model is based primarily on satellite imagery analysis provided nowadays globally at no cost. It is also straightforward and computationally inexpensive, requiring much less effort in comparison for example to field surveying. Finally, the method is adjustable to be potentially integrated with other high resolution data available from both commercial and non-commercial vendors. Keywords: Sensitivity analysis, frost risk mapping, GIS, remote sensing, MODIS, Greece

  18. Radiation-stable polyolefin compositions

    International Nuclear Information System (INIS)

    Rekers, J.W.

    1986-01-01

    This invention relates to compositions of olefinic polymers suitable for high energy radiation treatment. In particular, the invention relates to olefinic polymer compositions that are stable to sterilizing dosages of high energy radiation such as a gamma radiation. Stabilizers are described that include benzhydrol and benzhydrol derivatives; these stabilizers may be used alone or in combination with secondary antioxidants or synergists

  19. Monitoring of stable glaucoma patients

    NARCIS (Netherlands)

    K.M. Holtzer-Goor (Kim); N.S. Klazinga (Niek); M.A. Koopmanschap (Marc); H.G. Lemij (Hans); T. Plochg; E. van Sprundel (Esther)

    2010-01-01

    textabstractA high workload for ophthalmologists and long waiting lists for patients challenge the organization of ophthalmic care. Tasks that require less specialized skills, like the monitoring of stable (well controlled) glaucoma patients could be substituted from ophthalmologists to other

  20. Diet Quality and Nutrient Intake of Urban Overweight and Obese Primarily African American Older Adults with Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Sevasti Vergis

    2018-04-01

    Full Text Available Diet quality may be a unique target for preventing and managing obesity-related osteoarthritis (OA. Using the Healthy Eating Index-2010 (HEI-2010, this study examined the nutrient intake and diet quality of 400 urban overweight and obese primarily African American older adults with self-reported lower extremity OA. Associations between sociodemographic and health-related factors and diet quality were explored. Participants (mean age 67.8 years, SD 5.9 were included. Habitual dietary intake was assessed using a food frequency questionnaire (FFQ. Nutrient intake and diet quality were calculated from the FFQ. Results indicated that diet quality needs improvement (HEI-2010: 66.3 (SD 10.5. Age, body mass index, employment (multivariable model only, and OA severity (bivariate model only were significant predictors of HEI-2010 total score in linear models. Mean intakes for fiber, calcium, and vitamin D were below recommendations, while percentage of calories as total fat exceeded recommendations. These findings can inform future dietary intervention trials and public health messaging for a sub-population at a high risk for obesity-related OA.

  1. Semi-synthetic vNAR libraries screened against therapeutic antibodies primarily deliver anti-idiotypic binders.

    Science.gov (United States)

    Könning, Doreen; Rhiel, Laura; Empting, Martin; Grzeschik, Julius; Sellmann, Carolin; Schröter, Christian; Zielonka, Stefan; Dickgießer, Stephan; Pirzer, Thomas; Yanakieva, Desislava; Becker, Stefan; Kolmar, Harald

    2017-08-29

    Anti-idiotypic binders which specifically recognize the variable region of monoclonal antibodies have proven to be robust tools for pharmacokinetic studies of antibody therapeutics and for the development of cancer vaccines. In the present investigation, we focused on the identification of anti-idiotypic, shark-derived IgNAR antibody variable domains (vNARs) targeting the therapeutic antibodies matuzumab and cetuximab for the purpose of developing specific capturing ligands. Using yeast surface display and semi-synthetic, CDR3-randomized libraries, we identified several highly specific binders targeting both therapeutic antibodies in their corresponding variable region, without applying any counter selections during screening. Importantly, anti-idiotypic vNAR binders were not cross-reactive towards cetuximab or matuzumab, respectively, and comprised good target recognition in the presence of human and mouse serum. When coupled to magnetic beads, anti-idiotypic vNAR variants could be used as efficient capturing tools. Moreover, a two-step procedure involving vNAR-functionalized beads was employed for the enrichment of potentially bispecific cetuximab × matuzumab antibody constructs. In conclusion, semi-synthetic and CDR3-randomized vNAR libraries in combination with yeast display enable the fast and facile identification of anti-idiotypic vNAR domains targeting monoclonal antibodies primarily in an anti-idiotypic manner.

  2. Adolescent Pornography Use and Dating Violence among a Sample of Primarily Black and Hispanic, Urban-Residing, Underage Youth

    Directory of Open Access Journals (Sweden)

    Emily F. Rothman

    2015-12-01

    Full Text Available This cross-sectional study was designed to characterize the pornography viewing preferences of a sample of U.S.-based, urban-residing, economically disadvantaged, primarily Black and Hispanic youth (n = 72, and to assess whether pornography use was associated with experiences of adolescent dating abuse (ADA victimization. The sample was recruited from a large, urban, safety net hospital, and participants were 53% female, 59% Black, 19% Hispanic, 14% Other race, 6% White, and 1% Native American. All were 16–17 years old. More than half (51% had been asked to watch pornography together by a dating or sexual partner, and 44% had been asked to do something sexual that a partner saw in pornography. Adolescent dating abuse (ADA victimization was associated with more frequent pornography use, viewing pornography in the company of others, being asked to perform a sexual act that a partner first saw in pornography, and watching pornography during or after marijuana use. Approximately 50% of ADA victims and 32% of non-victims reported that they had been asked to do a sexual act that their partner saw in pornography (p = 0.15, and 58% did not feel happy to have been asked. Results suggest that weekly pornography use among underage, urban-residing youth is common, and may be associated with ADA victimization.

  3. Adolescent Pornography Use and Dating Violence among a Sample of Primarily Black and Hispanic, Urban-Residing, Underage Youth

    Science.gov (United States)

    Rothman, Emily F.; Adhia, Avanti

    2015-01-01

    This cross-sectional study was designed to characterize the pornography viewing preferences of a sample of U.S.-based, urban-residing, economically disadvantaged, primarily Black and Hispanic youth (n = 72), and to assess whether pornography use was associated with experiences of adolescent dating abuse (ADA) victimization. The sample was recruited from a large, urban, safety net hospital, and participants were 53% female, 59% Black, 19% Hispanic, 14% Other race, 6% White, and 1% Native American. All were 16–17 years old. More than half (51%) had been asked to watch pornography together by a dating or sexual partner, and 44% had been asked to do something sexual that a partner saw in pornography. Adolescent dating abuse (ADA) victimization was associated with more frequent pornography use, viewing pornography in the company of others, being asked to perform a sexual act that a partner first saw in pornography, and watching pornography during or after marijuana use. Approximately 50% of ADA victims and 32% of non-victims reported that they had been asked to do a sexual act that their partner saw in pornography (p = 0.15), and 58% did not feel happy to have been asked. Results suggest that weekly pornography use among underage, urban-residing youth may be common, and may be associated with ADA victimization. PMID:26703744

  4. Toward Practical Secure Stable Matching

    Directory of Open Access Journals (Sweden)

    Riazi M. Sadegh

    2017-01-01

    Full Text Available The Stable Matching (SM algorithm has been deployed in many real-world scenarios including the National Residency Matching Program (NRMP and financial applications such as matching of suppliers and consumers in capital markets. Since these applications typically involve highly sensitive information such as the underlying preference lists, their current implementations rely on trusted third parties. This paper introduces the first provably secure and scalable implementation of SM based on Yao’s garbled circuit protocol and Oblivious RAM (ORAM. Our scheme can securely compute a stable match for 8k pairs four orders of magnitude faster than the previously best known method. We achieve this by introducing a compact and efficient sub-linear size circuit. We even further decrease the computation cost by three orders of magnitude by proposing a novel technique to avoid unnecessary iterations in the SM algorithm. We evaluate our implementation for several problem sizes and plan to publish it as open-source.

  5. Y-Chromosomal Diversity in Europe Is Clinal and Influenced Primarily by Geography, Rather than by Language

    Science.gov (United States)

    Rosser, Zoë H.; Zerjal, Tatiana; Hurles, Matthew E.; Adojaan, Maarja; Alavantic, Dragan; Amorim, António; Amos, William; Armenteros, Manuel; Arroyo, Eduardo; Barbujani, Guido; Beckman, Gunhild; Beckman, Lars; Bertranpetit, Jaume; Bosch, Elena; Bradley, Daniel G.; Brede, Gaute; Cooper, Gillian; Côrte-Real, Helena B. S. M.; de Knijff, Peter; Decorte, Ronny; Dubrova, Yuri E.; Evgrafov, Oleg; Gilissen, Anja; Glisic, Sanja; Gölge, Mukaddes; Hill, Emmeline W.; Jeziorowska, Anna; Kalaydjieva, Luba; Kayser, Manfred; Kivisild, Toomas; Kravchenko, Sergey A.; Krumina, Astrida; Kučinskas, Vaidutis; Lavinha, João; Livshits, Ludmila A.; Malaspina, Patrizia; Maria, Syrrou; McElreavey, Ken; Meitinger, Thomas A.; Mikelsaar, Aavo-Valdur; Mitchell, R. John; Nafa, Khedoudja; Nicholson, Jayne; Nørby, Søren; Pandya, Arpita; Parik, Jüri; Patsalis, Philippos C.; Pereira, Luísa; Peterlin, Borut; Pielberg, Gerli; Prata, Maria João; Previderé, Carlo; Roewer, Lutz; Rootsi, Siiri; Rubinsztein, D. C.; Saillard, Juliette; Santos, Fabrício R.; Stefanescu, Gheorghe; Sykes, Bryan C.; Tolun, Aslihan; Villems, Richard; Tyler-Smith, Chris; Jobling, Mark A.

    2000-01-01

    Clinal patterns of autosomal genetic diversity within Europe have been interpreted in previous studies in terms of a Neolithic demic diffusion model for the spread of agriculture; in contrast, studies using mtDNA have traced many founding lineages to the Paleolithic and have not shown strongly clinal variation. We have used 11 human Y-chromosomal biallelic polymorphisms, defining 10 haplogroups, to analyze a sample of 3,616 Y chromosomes belonging to 47 European and circum-European populations. Patterns of geographic differentiation are highly nonrandom, and, when they are assessed using spatial autocorrelation analysis, they show significant clines for five of six haplogroups analyzed. Clines for two haplogroups, representing 45% of the chromosomes, are continentwide and consistent with the demic diffusion hypothesis. Clines for three other haplogroups each have different foci and are more regionally restricted and are likely to reflect distinct population movements, including one from north of the Black Sea. Principal-components analysis suggests that populations are related primarily on the basis of geography, rather than on the basis of linguistic affinity. This is confirmed in Mantel tests, which show a strong and highly significant partial correlation between genetics and geography but a low, nonsignificant partial correlation between genetics and language. Genetic-barrier analysis also indicates the primacy of geography in the shaping of patterns of variation. These patterns retain a strong signal of expansion from the Near East but also suggest that the demographic history of Europe has been complex and influenced by other major population movements, as well as by linguistic and geographic heterogeneities and the effects of drift. PMID:11078479

  6. Australian general practitioners initiate statin therapy primarily on the basis of lipid levels; New Zealand general practitioners use absolute risk.

    Science.gov (United States)

    Schilling, Chris; Knight, Josh; Mortimer, Duncan; Petrie, Dennis; Clarke, Philip; Chalmers, John; Kerr, Andrew; Jackson, Rod

    2017-12-01

    To compare the determinants of initial statin prescribing between New Zealand and Australia. New Zealand has a system-wide absolute risk-based approach to primary care cardiovascular disease (CVD) management, while Australia has multiple guidelines. Classification and Regression Tree (CART) analysis of two observational studies of primary care CVD management from New Zealand (PREDICT-CVD) and Australia (AusHeart). Over 80% of eligible New Zealanders have been screened for CVD risk. PREDICT-CVD is used by approximately one-third of New Zealand GPs to perform web-based CVD risk assessment in routine practice, with the sample consisting of 126,519 individuals risk assessed between 1 January 2007 and 30 June 2014. AusHeart is a cluster-stratified survey of primary care CVD management that enrolled 534 GPs from across Australia, who in turn recruited 1381 patients between 1 April and 30 June 2008. Eligibility was restricted to 55-74year old patients without prior CVD. The CART analyses demonstrated that New Zealand GPs prescribe statins primarily on the basis of absolute risk, while their Australian counterparts are influenced by a variety of individual risk factors, including total cholesterol, LDL cholesterol and diabetes. Countries seeking to improve their management of CVD should consider adopting a 'whole of system' absolute risk-based approach with clear guidelines that are consistent with drug reimbursement rules; and include computerized decision-support tools that aid decision-making and allow monitoring of outcomes and continual improvement of practice. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Ah receptor mediated suppression of the antibody response in mice is primarily dependent on the Ah phenotype of lymphoid tissue

    International Nuclear Information System (INIS)

    Silkworth, J.B.; Antrim, L.A.; Sack, G.

    1986-01-01

    Halogenated aromatic hydrocarbons act through the aromatic hydrocarbon (Ah) receptor in mice to produce a series of toxic effects of the immune system. The receptor protein is a product of the Ah gene locus. Ah responsive (Ahb/Ahb) mice express a high affinity receptor in both lymphoid and nonlymphoid tissues whereas nonresponsive Ahd/Ahd mice express a poor affinity receptor. To determine the role of the Ah receptor of lymphoid tissue relative to that of nonlymphoid tissue in the induction of immune impairment, bone marrow was used to reconstitute lethally irradiated mice of the same or opposite Ah phenotype. All mice were given 3,3',4,4'-tetrachlorobiphenyl (35 and 350 mumol/kg) ip 2 days before immunization with sheep erythrocytes (SRBC). The immune response to this T dependent antigen and organ weights were determined 5 or 7 days later in normal or chimeric mice, respectively. Monoclonal Lyt 1.1 and Lyt 1.2 antibodies were used to establish the origin of the cells which repopulated the chimeric thymuses. The immune responses of both BALB/cBy (Ahb/Ahb) and the BALB/cBy X DBA/2 hybrid, CByD2F1 (Ahb/Ahd), were significantly suppressed but DBA/2 mice were unaffected. The immune responses of chimeric BALB/cBy----BALB/cBy and BALB/cBy----DBA/2 (donor----recipient) mice were also significantly suppressed and thymic atrophy was observed in both cases. The serum anti-SRBC antibody titers of DBA/2----BALB/cBy chimeras were also significantly decreased although not to the same extent as in BALB/cBy----DBA/2 mice. Chimeric DBA/2----DBA/2 mice were not affected. These results indicate that the sensitivity to Ah receptor mediated suppression of the antibody response is primarily determined by the Ah phenotype of the lymphoid tissue

  8. Social Media Use and its Association with Sexual Risk and Parental Monitoring among a Primarily Hispanic Adolescent Population.

    Science.gov (United States)

    Romo, Dina L; Garnett, Chelsea; Younger, Alayna P; Stockwell, Melissa S; Soren, Karen; Catallozzi, Marina; Neu, Natalie

    2017-08-01

    In this study we assessed the association between social media (SM) use with sexual risk, and with parental monitoring among Hispanic adolescents. Self-administered anonymous survey. Urban primary care clinics. Primarily Hispanic adolescents ages 13-21 years old. Chi-square and regression analyses controlling for age and gender were used to assess associations between SM use or sexting and sexual behaviors (kissing, touching genitals, vaginal oral, and anal sex), sexual risk (≥4 lifetime partners, >1 recent partner, inconsistent condom use, and history of sexually transmitted infection diagnosis) and contraceptive use. Similar analyses were used to assess relationships between adolescent-reported parental monitoring and SM use, and sexting. Participants with frequent SM use (social networking sites or apps) had greater odds of all sexual activity. Ever sexters had greater odds of penetrative sex only (oral, vaginal, and anal sex) as well as use of hormonal contraception (except long-acting reversible contraception). Approximately half of the participants reported parental access to profiles on SM. Female participants had higher odds of parental access to online profiles and having a parental discussion of privacy settings. Those having privacy discussions had greater odds of "private" profiles on SM and lower odds of ever sexting. Frequent SM use and sexting was associated with an increase in all types of sexual behaviors; sexting alone was associated with more lifetime and recent sexual partners. Parental discussion of privacy settings was found to be protective. Providers and parents should be aware of the effect of SM use on sexual behaviors. Copyright © 2017 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

  9. Towards stable acceleration in LINACS

    CERN Document Server

    Dubrovskiy, A D

    2014-01-01

    Ultra-stable and -reproducible high-energy particle beams with short bunches are needed in novel linear accelerators and, in particular, in the Compact Linear Collider CLIC. A passive beam phase stabilization system based on a bunch compression with a negative transfer matrix element R56 and acceleration at a positive off-crest phase is proposed. The motivation and expected advantages of the proposed scheme are outlined.

  10. Unencapsulated Air-stable Organic Field Effect Transistor by All Solution Processes for Low Power Vapor Sensing

    Science.gov (United States)

    Feng, Linrun; Tang, Wei; Zhao, Jiaqing; Yang, Ruozhang; Hu, Wei; Li, Qiaofeng; Wang, Ruolin; Guo, Xiaojun

    2016-02-01

    With its excellent mechanical flexibility, low-cost and low-temperature processing, the solution processed organic field-effect transistor (OFET) is a promising platform technology for developing ubiquitous sensor applications in digital health, environment monitoring and Internet of Things. However, a contradiction between achieving low voltage operation and having stable performance severely hinder the technology to become commercially viable. This work shows that, by reducing the sub-gap density of states (DOS) at the channel for low operation voltage and using a proper low-k non-polar polymer dielectric layer, such an issue can be addressed. Stable electrical properties after either being placed for weeks or continuously prolonged bias stressing for hours in ambient air are achieved for all solution processed unencapsulated OFETs with the channel being exposed to the ambient air for analyte detection. The fabricated device presents a steep subthreshold swing less than 100 mV/decade, and an ON/OFF ratio of 106 at a voltage swing of 3 V. The low voltage and stable operation allows the sensor made of the OFET to be incorporated into a battery-powered electronic system for continuously reliable sensing of ammonia vapor in ambient air with very small power consumption of about 50 nW.

  11. 49 CFR 37.195 - Purchase or lease of OTRBs by private entities not primarily in the business of transporting people.

    Science.gov (United States)

    2010-10-01

    ... primarily in the business of transporting people. 37.195 Section 37.195 Transportation Office of the... transporting people. This section applies to all purchases or leases of new vehicles by private entities which are not primarily engaged in the business of transporting people, with respect to buses delivered to...

  12. TRPA1 is functionally expressed primarily by IB4-binding, non-peptidergic mouse and rat sensory neurons.

    Directory of Open Access Journals (Sweden)

    Marie E Barabas

    functionally expressed primarily in the IB4-positive, CGRP-negative subpopulation of small lumbar DRG neurons from rodents. Thus, IB4 binding is a better indicator than neuropeptides for TRPA1 expression.

  13. One-pot synthesis of stable colloidal solutions of MFe{sub 2}O{sub 4} nanoparticles using oleylamine as solvent and stabilizer

    Energy Technology Data Exchange (ETDEWEB)

    Pérez-Mirabet, Leonardo [Departament de Química, Universitat Autònoma de Barcelona, Campus de la UAB, 08193 Bellaterra (Spain); Solano, Eduardo, E-mail: eduardo.solano@uab.cat [Departament de Química, Universitat Autònoma de Barcelona, Campus de la UAB, 08193 Bellaterra (Spain); Martínez-Julián, Fernando; Guzmán, Roger [Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus de la UAB, 08193 Bellaterra (Spain); Arbiol, Jordi [Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus de la UAB, 08193 Bellaterra (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA), 08019 Barcelona (Spain); Puig, Teresa; Obradors, Xavier; Pomar, Alberto [Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus de la UAB, 08193 Bellaterra (Spain); Yáñez, Ramón; Ros, Josep [Departament de Química, Universitat Autònoma de Barcelona, Campus de la UAB, 08193 Bellaterra (Spain); Ricart, Susagna [Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus de la UAB, 08193 Bellaterra (Spain)

    2013-03-15

    Highlights: ► One-pot synthesis of ferrite magnetic nanoparticles (<10 nm) in non-polar media. ► Nanoparticles present high monocrystal quality and monodispersion. ► Superparamagnetic behavior at room temperature. ► Nanoparticles transfer to polar media via ligand exchange. - Abstract: An easy, efficient, reproducible and scalable one-pot synthetic methodology to obtain magnetic spinel ferrite nanoparticles has been developed. This approach is based on one-pot thermal decomposition of Fe(acac){sub 3} and M(acac){sub 2} (M = Co, Mn, Cu and Zn) in oleylamine, which also acts as a capping ligand, by producing stable colloidal dispersions of nanoparticles in non-polar solvents. The properties of the nanoparticles have been studied via different techniques, such as transmission electron microscopy, which shows that nanoparticles are monocrystallines and a narrow dispersion in size; magnetic analyses have demonstrated that the resulting ferrite nanoparticles show high saturation values and superparamagnetic behavior at room temperature; X-ray diffraction has also been performed, and it confirms that the synthesized nanoparticles have a spinel structure. Complementarily, ligand exchange has been also carried out in order to produce dispersions of the synthesized nanoparticles in polar media.

  14. Stable Hemiaminals: 2-Aminopyrimidine Derivatives

    Directory of Open Access Journals (Sweden)

    Anna Kwiecień

    2015-08-01

    Full Text Available Stable hemiaminals can be obtained in the one-pot reaction between 2-aminopyrimidine and nitrobenzaldehyde derivatives. Ten new hemiaminals have been obtained, six of them in crystal state. The molecular stability of these intermediates results from the presence of both electron-withdrawing nitro groups as substituents on the phenyl ring and pyrimidine ring, so no further stabilisation by intramolecular interaction is required. Hemiaminal molecules possess a tetrahedral carbon atom constituting a stereogenic centre. As the result of crystallisation in centrosymmetric space groups both enantiomers are present in the crystal structure.

  15. Organic synthesis with stable isotopes

    International Nuclear Information System (INIS)

    Daub, G.H.; Kerr, V.N.; Williams, D.L.; Whaley, T.W.

    1978-01-01

    Some general considerations concerning organic synthesis with stable isotopes are presented. Illustrative examples are described and discussed. The examples include DL-2-amino-3-methyl- 13 C-butanoic-3,4- 13 C 2 acid (DL-valine- 13 C 3 ); methyl oleate-1- 13 C; thymine-2,6- 13 C 2 ; 2-aminoethanesulfonic- 13 C acid (taurine- 13 C); D-glucose-6- 13 C; DL-2-amino-3-methylpentanoic-3,4- 13 C 2 acid (DL-isoleucine- 13 C 2 ); benzidine- 15 N 2 ; and 4-ethylsulfonyl-1-naphthalene-sulfonamide- 15 N

  16. Stable agents for imaging investigations

    International Nuclear Information System (INIS)

    Tofe, A.J.

    1976-01-01

    This invention concerns highly stable compounds useful in preparing technetium 99m based scintiscanning exploration agents. The compounds of this invention include a pertechnetate reducing agent or a solution of oxidized pertechnetate and an efficient proportion, sufficient to stabilize the compounds in the presence of oxygen and of radiolysis products, of ascorbic acid or a pharmaceutically acceptable salt or ester of this acid. The invention also concerns a perfected process for preparing a technetium based exploration agent, consisting in codissolving the ascorbic acid or a pharmaceutically acceptable salt or ester of such an acid and a pertechnetate reducing agent in a solution of oxidized pertechnetate [fr

  17. New Vistas on the Anionic Polymerization of Styrene in Non-Polar Solvents by Means of Density Functional Theory

    Directory of Open Access Journals (Sweden)

    Hideo Morita

    2016-10-01

    Full Text Available The elementary processes of anionic styrene polymerization in the gas phase and in cyclohexane were studied using M062X (a recently developed density functional theory (DFT method combined with the 6-31+G(d basis sets, in order to clarify the complicated phenomena caused by the association of the active chain-ends and elucidate the details of the polymerization mechanism. Three types of HSt2Li (a model structure of polystyryllithium chain-ends were obtained; the well-known first structure in which Li is coordinated to the side chain, the second structure in which Li is coordinated to the phenyl ring, (both without the penultimate unit coordination, and the third structure in which Li is coordinated to both the chain-end unit and the penultimate styrene unit. Although the third HSt2Li is the most stable as expected, the free energy for the transition state of its reaction with styrene is higher than those for the other two transition states due to its steric hindrance. The free energy for the transition state of the reaction of the second HSt2Li with styrene is the lowest, suggesting that the route through it is the predominant reaction path. The penultimate unit effect, slower addition of styrene to HSt2Li than to HStLi, is attributed to coordination of the penultimate styrene units of the polystyryllithium dimer (one of the starting materials to its Li atoms. The calculated enthalpy for the reaction barrier of the second HSt2Li with styrene in cyclohexane was found to agree with the observed apparent activation energy in benzene.

  18. A HIGH SENSITIVE MICROWAVE MEASURING DEVICE OF THE MOISTURE CONTENT IN THE NON-POLAR DIELECTRIC LIQUIDS BASED ON AN INHOMOGENEOUS STEP COAXIAL RESONATOR

    Directory of Open Access Journals (Sweden)

    V. V. Rudakov

    2016-11-01

    Full Text Available Purpose. Objective is to create a moisture meter for non-polar liquid dielectrics with low volumetric moisture content of more than 10‑3 %. Methodology. Moisture measuring is based on dielcometric method. It is implemented as a resonant method of determining a capacitance measuring transducer. Measuring transducer capacitive type has a working and parasitic capacitance. It was suggested the definition of moisture on four of resonance frequencies: when the measuring transducer is turned off, one by one filled with air, «dry» and investigated liquid, to determine the parasitic capacitance of the measuring generator, and the parasitic capacitance of the measuring transducer and humidity. Measurement frequency was increased up to microwave range to increase the sensitivity. Measuring transducer with distributed parameters representing a step heterogeneous coaxial resonator is used by. This measuring transducer has a zero stray capacitance, because the potential electrode has a galvanic connection with an external coaxial electrode. Inductive ties loop is used to neglect parasitic capacitance of the measuring generator, and to increase the quality factor of the system. Measuring moisture is reduced to measuring the two frequencies of resonance frequency and «dry» and investigated liquid. Resonant characteristics transducer in a step inhomogeneous coaxial resonator have been investigated to determine the quality factor of filled with air and transformer oil, and experiments to measure the moisture content in transformer oil have been conducted. Results. Measuring transducer of distributed type is developed and researched – it is step inhomogeneous coaxial resonator. It has a smaller geometric length and larger scatter of the first and second resonant frequencies. Expression is obtained for determination of moisture on the basis of two resonant frequencies. The formula of the two frequencies to determine the moisture is correct. Resonant

  19. Stable cosmology in chameleon bigravity

    Science.gov (United States)

    De Felice, Antonio; Mukohyama, Shinji; Oliosi, Michele; Watanabe, Yota

    2018-02-01

    The recently proposed chameleonic extension of bigravity theory, by including a scalar field dependence in the graviton potential, avoids several fine-tunings found to be necessary in usual massive bigravity. In particular it ensures that the Higuchi bound is satisfied at all scales, that no Vainshtein mechanism is needed to satisfy Solar System experiments, and that the strong coupling scale is always above the scale of cosmological interest all the way up to the early Universe. This paper extends the previous work by presenting a stable example of cosmology in the chameleon bigravity model. We find a set of initial conditions and parameters such that the derived stability conditions on general flat Friedmann background are satisfied at all times. The evolution goes through radiation-dominated, matter-dominated, and de Sitter eras. We argue that the parameter space allowing for such a stable evolution may be large enough to encompass an observationally viable evolution. We also argue that our model satisfies all known constraints due to gravitational wave observations so far and thus can be considered as a unique testing ground of gravitational wave phenomenologies in bimetric theories of gravity.

  20. Stable isotope mass spectrometry in petroleum exploration

    International Nuclear Information System (INIS)

    Mathur, Manju

    1997-01-01

    The stable isotope mass spectrometry plays an important role to evaluate the stable isotopic composition of hydrocarbons. The isotopic ratios of certain elements in petroleum samples reflect certain characteristics which are useful for petroleum exploration

  1. Optical properties of InN nanocolumns: Electron accumulation at InN non-polar surfaces and dependence on the growth conditions

    Energy Technology Data Exchange (ETDEWEB)

    Segura-Ruiz, J.; Cantarero, A. [Materials Science Institute, University of Valencia (Spain); Garro, N. [Materials Science Institute, University of Valencia (Spain); Fundacio General de la Universitat de Valencia, Valencia (Spain); Iikawa, F. [Instituto de Fisica ' ' Gleb Wataghin' ' , UNICAMP, Campinas-SP (Brazil); Denker, C.; Malindretos, J.; Rizzi, A. [IV. Physikalisches Institut, Georg-August Universitaet Goettingen (Germany)

    2009-06-15

    InN nanocolumns grown by plasma-assisted molecular beam epitaxy have been studied by photoluminescence (PL) and photoluminescence excitation (PLE). The PL peak energy was red-shifted with respect to the PLE onset and both energies were higher than the low temperature band-gap reported for InN. PL and PLE experiments for different excitation and detection energies indicated that the PL peaks were homogeneously broadened. This overall phenomenology has been attributed to the effects of an electron accumulation layer present at the non-polar surfaces of the InN nanocolumns. Variations in the growth conditions modify the edge of the PLE spectra and the PL peak energies evidencing that the density of free electrons can be somehow controlled by the growth parameters. It was observed that In-BEP and substrate temperature leading to shorter In diffusion lengths diminished the effects of the electron accumulation layer on the optical properties. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Optical properties of InN nanocolumns: Electron accumulation at InN non-polar surfaces and dependence on the growth conditions

    International Nuclear Information System (INIS)

    Segura-Ruiz, J.; Cantarero, A.; Garro, N.; Iikawa, F.; Denker, C.; Malindretos, J.; Rizzi, A.

    2009-01-01

    InN nanocolumns grown by plasma-assisted molecular beam epitaxy have been studied by photoluminescence (PL) and photoluminescence excitation (PLE). The PL peak energy was red-shifted with respect to the PLE onset and both energies were higher than the low temperature band-gap reported for InN. PL and PLE experiments for different excitation and detection energies indicated that the PL peaks were homogeneously broadened. This overall phenomenology has been attributed to the effects of an electron accumulation layer present at the non-polar surfaces of the InN nanocolumns. Variations in the growth conditions modify the edge of the PLE spectra and the PL peak energies evidencing that the density of free electrons can be somehow controlled by the growth parameters. It was observed that In-BEP and substrate temperature leading to shorter In diffusion lengths diminished the effects of the electron accumulation layer on the optical properties. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Uptake calibration of polymer-based passive samplers for monitoring priority and emerging organic non-polar pollutants in WWTP effluents.

    Science.gov (United States)

    Posada-Ureta, Oscar; Olivares, Maitane; Zatón, Leire; Delgado, Alejandra; Prieto, Ailette; Vallejo, Asier; Paschke, Albrecht; Etxebarria, Nestor

    2016-05-01

    The uptake calibration of more than 12 non-polar organic contaminants by 3 polymeric materials is shown: bare polydimetilsiloxane (PDMS, stir-bars), polyethersulfone tubes and membranes (PES) and polyoxymethylene membranes (POM), both in their free form and membrane-enclosed sorptive coating (MESCO). The calibration process was carried out exposing the samplers to a continuous flow of contaminated water at 100 ng mL(-1) for up to 28 days, and, consequently, the sampling rates (Rs, mL day(-1)) of several organic microcontaminants were provided for the first time. In situ Rs values were also determined disposing the samplers in the effluent of a wastewater treatment plant. Finally, these passive samplers were applied to monitor the effluents of two wastewater treatment plants. This application lead to the confirmation of the presence of galaxolide, tonalide and 4-tert-octylphenol at high ng mL(-1) levels, as well as the identification of compounds like some phthalates and alkylphenols at levels below the detection limits for active sampling methods.

  4. How do glycerol and dimethyl sulphoxide affect local tetrahedral structure of water around a nonpolar solute at low temperature? Importance of preferential interaction

    Science.gov (United States)

    Daschakraborty, Snehasis

    2018-04-01

    Glycerol and dimethyl sulphoxide (DMSO) have vital roles in cryoprotection of living cells, tissues, etc. The above action has been directly linked with disruption of hydrogen (H-) bond structure and dynamics of water by these cosolvents at bulk region and around various complex units, such as peptide, amino acid, protein, and lipid membrane. However, the disruption of the local structure of the water solvent around a purely hydrophobic solute is still not studied extensively. The latter is also important in the context of stabilization of protein from cold denaturation. Through all-atom molecular dynamics simulation, we have investigated the comparative effect of glycerol and DMSO on the orientational order of water around a nonpolar solute at -5 °C. A steady reduction of the tetrahedral order of water is observed at bulk (>10 Å distance from the solute) and solute interface (determines whether the involvement of the cosolvent molecules in H-bonding with solvent water in the interface is akin to the bulk region or not.

  5. Study of 3D-growth conditions for selective area MOVPE of high aspect ratio GaN fins with non-polar vertical sidewalls

    Science.gov (United States)

    Hartmann, Jana; Steib, Frederik; Zhou, Hao; Ledig, Johannes; Nicolai, Lars; Fündling, Sönke; Schimpke, Tilman; Avramescu, Adrian; Varghese, Tansen; Trampert, Achim; Straßburg, Martin; Lugauer, Hans-Jürgen; Wehmann, Hergo-Heinrich; Waag, Andreas

    2017-10-01

    GaN fins are 3D architectures elongated in one direction parallel to the substrate surface. They have the geometry of walls with a large height to width ratio as well as small footprints. When appropriate symmetry directions of the GaN buffer are used, the sidewalls are formed by non-polar {1 1 -2 0} planes, making the fins particularly suitable for many device applications like LEDs, FETs, lasers, sensors or waveguides. The influence of growth parameters like temperature, pressure, V/III ratio and total precursor flow on the fin structures is analyzed. Based on these results, a 2-temperature-step-growth was developed, leading to fins with smooth side and top facets, fast vertical growth rates and good homogeneity along their length as well as over different mask patterns. For the core-shell growth of fin LED heterostructures, the 2-temperature-step-growth shows much smoother sidewalls and less crystal defects in the InGaN QW and p-GaN shell compared to structures with cores grown in just one step. Electroluminescence spectra of the 2-temperature-step-grown fin LED are demonstrated.

  6. Nonpolar nitrous oxide dimer: Observation of combination bands of (14N2O)2 and (15N2O)2 involving the torsion and antigeared bending modes

    Science.gov (United States)

    Rezaei, M.; Michaelian, K. H.; Moazzen-Ahmadi, N.

    2012-03-01

    Spectra of the nonpolar nitrous oxide dimer in the region of the N2O ν1 fundamental band were observed in a supersonic slit-jet apparatus. The expansion gas was probed using radiation from a quantum cascade or a tunable diode laser, with both lasers employed in a rapid-scan signal averaging mode. Four bands were observed and analyzed: new combination bands involving the intermolecular conrotation of the monomers (Ag antigeared bend) for (14N2O)2 and (15N2O)2, the previously reported torsional combination band for (14N2O)2 with improved signal-to-noise ratio, and the same torsional combination band for (15N2O)2. The resulting frequencies for the intermolecular antigeared mode are 96.0926(1) and 95.4912(1) cm-1 for (14N2O)2 and (15N2O)2, respectively. This is the third of the four intermolecular frequencies which has now been measured experimentally, the others being the out-of-plane torsion and the geared bend modes. Our experimental results are in good agreement with two recent high level ab initio theoretical calculations.

  7. In vitro biocompatibility and proliferative effects of polar and non-polar extracts of cucurbita ficifolia on human mesenchymal stem cells.

    Science.gov (United States)

    Aristatile, Balakrishnan; Alshammari, Ghedeir M

    2017-05-01

    Cucurbita ficifolia (C. ficifolia) has been traditionally known for its medicinal properties as an antioxidant, anti-diabetic and anti-inflammatory agent. However, there has been an enduring attention towards the identification of unique method, to isolate the natural components for therapeutic applications. Our study focuses on different polar and non-polar solvents (methanol, hexane and chloroform) to extract the bioactive components from C. ficifolia (pumpkin) and to study the biocompatibility and cytotoxicity effects on human bone marrow-mesenchymal stem cells (hBM-MSCs). The extracts were screened for their effects on cytotoxicity, cell proliferation and cell cycle on the hBM-MSCs cell line. The assays demonstrated that the chloroform extract was highly biocompatible, with less cytotoxic effect, and enhanced the cell proliferation. The methanol extract did not exhibit significant cytotoxicity when compare to the control. Concordantly, the cell cycle analysis confirmed that chloroform extract enhances the proliferation at lower concentrations. On the other hand, hexane extract showed high level of cytotoxicity with apoptotic and necrotic changes in hBM-MSCs. Collectively, our data revealed that chloroform is a good candidate to extract the bioactive components from C. ficifolia. Furthermore, our results suggest that specific gravity and density of the solvent might play a crucial role in the extraction process, which warrants further investigations. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  8. Structural TEM study of nonpolar a-plane gallium nitride grown on(112_0) 4H-SiC by organometallic vapor phase epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Zakharov, Dmitri N.; Liliental-Weber, Zuzanna; Wagner, Brian; Reitmeier,Zachary J.; Preble, Edward A.; Davis, Robert F.

    2005-04-05

    Conventional and high resolution electron microscopy havebeen applied for studying lattice defects in nonpolar a-plane GaN grownon a 4H-SiC substrate with an AlN buffer layer. Samples in plan-view andcross-section configurations have been investigated. Basal and prismaticstacking faults together with Frank and Shockley partial dislocationswere found to be the main defects in the GaN layers. High resolutionelectron microscopy in combination with image simulation supported Drum smodel for the prismatic stacking faults. The density of basal stackingfaults was measured to be ~;1.6_106cm-1. The densities of partialdislocations terminating I1 and I2 types of intrinsic basal stackingfaults were ~;4.0_1010cm-2 and ~;0.4_1010cm-2, respectively. The energyof the I2 stacking fault in GaN was estimated to be (40+-4) erg/cm2 basedon the separation of Shockley partial dislocations. To the best of ourknowledge, the theoretically predicted I3 basal stacking fault in GaN wasobserved experimentally for the first time.

  9. The 2140 cm(exp -1) (4.673 Microns) Solid CO Band: The Case for Interstellar O2 and N2 and the Photochemistry of Non-Polar Interstellar Ice Analogs

    Science.gov (United States)

    Elsila, Jamie; Allamandola, Louis J.; Sandford, Scott A.; Witteborn, Fred C. (Technical Monitor)

    1996-01-01

    The infrared spectra of CO frozen in non-polar ices containing N2, CO2, O2, and H2O, and the ultraviolet photochemistry of these interstellar/precometary ice analogs are reported. The spectra are used to test the hypothesis that the narrow 2140/cm (4.673 micrometer) interstellar absorption feature attributed to solid CO might be produced by CO frozen in ices containing non-polar species such as N2 and O2. It is shown that mixed molecular ices containing CO, N2, O2, and CO2 provide a very good match to the interstellar band at all temperatures between 12 and 30 K both before and after photolysis. The optical constants (real and imaginary parts of the index of refraction) in the region of the solid CO feature are reported for several of these ices.

  10. Stable rotating dipole solitons in nonlocal media

    DEFF Research Database (Denmark)

    Lopez-Aguayo, Servando; Skupin, Stefan; Desyatnikov, Anton S.

    2006-01-01

    We present the first example of stable rotating two-soliton bound states in nonlinear optical media with nonlocal response. We show that, in contrast to media with local response, nonlocality opens possibilities to generate stable azimuthons.......We present the first example of stable rotating two-soliton bound states in nonlinear optical media with nonlocal response. We show that, in contrast to media with local response, nonlocality opens possibilities to generate stable azimuthons....

  11. Uses of stable isotopes in fish ecology

    Science.gov (United States)

    Analyses of fish tissues (other than otoliths) for stable isotope ratios can provide substantial information on fish ecology, including physiological ecology. Stable isotopes of nitrogen and carbon frequently are used to determine the mix of diet sources for consumers. Stable i...

  12. Periodicity of the stable isotopes

    CERN Document Server

    Boeyens, J C A

    2003-01-01

    It is demonstrated that all stable (non-radioactive) isotopes are formally interrelated as the products of systematically adding alpha particles to four elementary units. The region of stability against radioactive decay is shown to obey a general trend based on number theory and contains the periodic law of the elements as a special case. This general law restricts the number of what may be considered as natural elements to 100 and is based on a proton:neutron ratio that matches the golden ratio, characteristic of biological and crystal growth structures. Different forms of the periodic table inferred at other proton:neutron ratios indicate that the electronic configuration of atoms is variable and may be a function of environmental pressure. Cosmic consequences of this postulate are examined. (author)

  13. Stable States of Biological Organisms

    Science.gov (United States)

    Yukalov, V. I.; Sornette, D.; Yukalova, E. P.; Henry, J.-Y.; Cobb, J. P.

    2009-04-01

    A novel model of biological organisms is advanced, treating an organism as a self-consistent system subject to a pathogen flux. The principal novelty of the model is that it describes not some parts, but a biological organism as a whole. The organism is modeled by a five-dimensional dynamical system. The organism homeostasis is described by the evolution equations for five interacting components: healthy cells, ill cells, innate immune cells, specific immune cells, and pathogens. The stability analysis demonstrates that, in a wide domain of the parameter space, the system exhibits robust structural stability. There always exist four stable stationary solutions characterizing four qualitatively differing states of the organism: alive state, boundary state, critical state, and dead state.

  14. Theory of stable allocations II

    Directory of Open Access Journals (Sweden)

    Pantelić Svetlana

    2015-01-01

    Full Text Available The Swedish Royal Academy awarded the 2012 Nobel Prize in Economics to Lloyd Shapley and Alvin Roth, for the theory of stable allocations and the practice of market design. These two American researchers worked independently from each other, combining basic theory and empirical investigations. Through their experiments and practical design they generated a flourishing field of research and improved the performance of many markets. Shapley provided the fundamental theoretical contribution to this field of research, whereas Roth, a professor at the Harvard University in Boston, developed and upgraded these theoretical investigations by applying them to the American market of medical doctors. Namely, their research helps explain the market processes at work, for instance, when doctors are assigned to hospitals, students to schools and human organs for transplant to recipients.

  15. Stable massive particles at colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fairbairn, M.; /Stockholm U.; Kraan, A.C.; /Pennsylvania U.; Milstead, D.A.; /Stockholm U.; Sjostrand, T.; /Lund U.; Skands, P.; /Fermilab; Sloan, T.; /Lancaster U.

    2006-11-01

    We review the theoretical motivations and experimental status of searches for stable massive particles (SMPs) which could be sufficiently long-lived as to be directly detected at collider experiments. The discovery of such particles would address a number of important questions in modern physics including the origin and composition of dark matter in the universe and the unification of the fundamental forces. This review describes the techniques used in SMP-searches at collider experiments and the limits so far obtained on the production of SMPs which possess various colour, electric and magnetic charge quantum numbers. We also describe theoretical scenarios which predict SMPs, the phenomenology needed to model their production at colliders and interactions with matter. In addition, the interplay between collider searches and open questions in cosmology such as dark matter composition are addressed.

  16. Stable Treemaps via Local Moves.

    Science.gov (United States)

    Sondag, Max; Speckmann, Bettina; Verbeek, Kevin

    2018-01-01

    Treemaps are a popular tool to visualize hierarchical data: items are represented by nested rectangles and the area of each rectangle corresponds to the data being visualized for this item. The visual quality of a treemap is commonly measured via the aspect ratio of the rectangles. If the data changes, then a second important quality criterion is the stability of the treemap: how much does the treemap change as the data changes. We present a novel stable treemapping algorithm that has very high visual quality. Whereas existing treemapping algorithms generally recompute the treemap every time the input changes, our algorithm changes the layout of the treemap using only local modifications. This approach not only gives us direct control over stability, but it also allows us to use a larger set of possible layouts, thus provably resulting in treemaps of higher visual quality compared to existing algorithms. We further prove that we can reach all possible treemap layouts using only our local modifications. Furthermore, we introduce a new measure for stability that better captures the relative positions of rectangles. We finally show via experiments on real-world data that our algorithm outperforms existing treemapping algorithms also in practice on either visual quality and/or stability. Our algorithm scores high on stability regardless of whether we use an existing stability measure or our new measure.

  17. Chemokine Receptor Expression Identifies Pre–T Helper (Th)1, Pre–Th2, and Nonpolarized Cells among Human CD4+ Central Memory T Cells

    Science.gov (United States)

    Rivino, Laura; Messi, Mara; Jarrossay, David; Lanzavecchia, Antonio; Sallusto, Federica; Geginat, Jens

    2004-01-01

    We previously reported that central–memory T cells (TCM cells), which express lymph node homing receptors CCR7 and CD62L, are largely devoid of effector functions but acquire characteristics of effector–memory T cells (TEM cells) (i.e., CCR7− T helper [Th]1 or Th2 cells) after stimulation with T cell receptor agonists or homeostatic cytokines. Here we show that three chemokine receptors identify functional subsets within the human CD4+ TCM cell pool. TCM cells expressing CXCR3 secreted low amounts of interferon γ, whereas CCR4+ TCM cells produced some interleukin (IL)-4, but not IL-5. In response to IL-7 and IL-15, CXCR3+ TCM and CCR4+ TCM cells invariably generated fully differentiated CCR7− Th1 and Th2 cells, respectively, suggesting that they represent pre-Th1 and pre-Th2 cells. Conversely, CXCR5+ TCM cells lacking CXCR3 and CCR4 remained nonpolarized and retained CCR7 and CD62L expression upon cytokine-driven expansion. Unlike naive cells, all memory subsets had a low T cell receptor rearrangement excision circle content, spontaneously incorporated bromodeoxyuridine ex vivo, and contained cells specific for tetanus toxoid. Conversely, recall responses to cytomegalovirus and vaccinia virus were largely restricted to CXCR3+ TCM and TEM cells. We conclude that antigen-specific memory T cells are distributed between TEM cells and different subsets of TCM cells. Our results also explain how the quality of primary T cell responses could be maintained by TCM cells in the absence of antigen. PMID:15381728

  18. Nonpolar a-plane GaN grown on r-plane sapphire using multilayer AlN buffer by metalorganic chemical vapor deposition

    International Nuclear Information System (INIS)

    Chiang, C.H.; Chen, K.M.; Wu, Y.H.; Yeh, Y.S.; Lee, W.I.; Chen, J.F.; Lin, K.L.; Hsiao, Y.L.; Huang, W.C.; Chang, E.Y.

    2011-01-01

    Mirror-like and pit-free non-polar a-plane (1 1 -2 0) GaN films are grown on r-plane (1 -1 0 2) sapphire substrates using metalorganic chemical vapor deposition (MOCVD) with multilayer high-low-high temperature AlN buffer layers. The buffer layer structure and film quality are essential to the growth of a flat, crack-free and pit-free a-plane GaN film. The multilayer AlN buffer structure includes a thin low-temperature-deposited AlN (LT-AlN) layer inserted into the high-temperature-deposited AlN (HT-AlN) layer. The results demonstrate that the multilayer AlN buffer structure can improve the surface morphology of the upper a-plane GaN film. The grown multilayer AlN buffer structure reduced the tensile stress on the AlN buffer layers and increased the compressive stress on the a-plane GaN film. The multilayer AlN buffer structure markedly improves the surface morphology of the a-plane GaN film, as revealed by scanning electron microscopy. The effects of various growth V/III ratios was investigated to obtain a-plane GaN films with better surface morphology. The mean roughness of the surface was 1.02 nm, as revealed by atomic force microscopy. Accordingly, the multilayer AlN buffer structure improves the surface morphology and facilitates the complete coalescence of the a-plane GaN layer.

  19. Characterization of HDEHP-lanthanide complexes formed in a non-polar organic phase using 31P NMR and ESI-MS.

    Science.gov (United States)

    Marie, Cécile; Hiscox, Bill; Nash, Kenneth L

    2012-01-21

    HDEHP (di-2-ethylhexylphosphoric acid) is one of the extractant molecules most intensively used in liquid-liquid extraction systems. Of particular interest in this investigation is its application in the TALSPEAK process, which is among the methods currently considered to be ready for technological deployment for the separation of trivalent actinides (Am(III) and Cm(III)) from lanthanide (Ln(III)) cations. However, several fundamental features of the chemistry of this separation system are not well understood. It has become clear that the lactic acid (LacH), which is employed as a buffer in the aqueous phase, plays a very complex role in the biphasic chemistry of the system. In this study, Nuclear Magnetic Resonance ((31)P NMR) was used to investigate the rate of HDEHP (AH) exchange occurring in the binary complexes Ln(AHA)(3) (Ln = La and Sm), which are usually considered to be the predominant species present in a non-polar organic phase (1,3-diisopropylbenzene). The rate data indicate considerably faster ligand exchange kinetics for La(AHA)(3) than is seen for Sm(AHA)(3), with a corresponding shift from a dissociative interchange to an associative process. With the introduction of lactic acid (LacH) and higher concentrations of lanthanides into the system, ternary complexes (Ln(3+)-HDEHP-lactate) become dominant, as demonstrated using (31)P NMR and Electrospray Ionization Mass Spectrometry (ESI-MS). Lactate partitioning experiments indicate that the amount of lactate extracted is correlated with the concentration of Ln(3+). The terminal ternary complex species appears to have the general stoichiometry 1 : 2 : 1 (Ln(3+) : HDEHP : lactate). The detection of bimetallic ternary complexes (by ESI-MS) with La(3+) and the observation of multiple phosphorus environments (by NMR) suggest the presence of polymetallic complexes with the general formula (LaA(2)Lac)(n). A model is proposed in which DEHP(-) molecules bridge two metal ions.

  20. Molecular dynamics studies of InGaN growth on nonpolar (11 2 \\xAF0 ) GaN surfaces

    Science.gov (United States)

    Chu, K.; Gruber, J.; Zhou, X. W.; Jones, R. E.; Lee, S. R.; Tucker, G. J.

    2018-01-01

    We have performed direct molecular dynamics (MD) simulations of heteroepitaxial vapor deposition of I nxG a1 -xN films on nonpolar (11 2 ¯0 ) wurtzite-GaN surfaces to investigate strain relaxation by misfit-dislocation formation. The simulated growth is conducted on an atypically large scale by sequentially injecting nearly a million individual vapor-phase atoms towards a fixed GaN substrate. We apply time-and-position-dependent boundary constraints to affect the appropriate environments for the vapor phase, the near-surface solid phase, and the bulklike regions of the growing layer. The simulations employ a newly optimized Stillinger-Weber In-Ga-N system interatomic potential wherein multiple binary and ternary structures are included in the underlying density-functional theory and experimental training sets to improve the treatment of the In-Ga-N related interactions. To examine the effect of growth conditions, we study a matrix of 63 different MD-growth simulations spanning seven I nxG a1 -xN -alloy compositions ranging from x =0.0 to x =0.8 and nine growth temperatures above half the simulated melt temperature. We found a composition dependent temperature range where all kinetically trapped defects were eliminated, leaving only quasiequilibrium misfit and threading dislocations present in the simulated films. Based on the MD results obtained in this temperature range, we observe the formation of interfacial misfit and threading dislocation arrays with morphologies strikingly close to those seen in experiments. In addition, we compare the MD-observed thickness-dependent onset of misfit-dislocation formation to continuum-elasticity-theory models of the critical thickness and find reasonably good agreement. Finally, we use the three-dimensional atomistic details uniquely available in the MD-growth histories to directly observe the nucleation of dislocations at surface pits in the evolving free surface.

  1. Phenotype of hepatic infiltrates and hepatic lymph nodes of lambs primarily and challenge infected with Fasciola hepatica, with and without triclabendazole treatment.

    Science.gov (United States)

    Pérez, José; Ortega, Joaquín; Bravo, Ana; Díez-Baños, Pablo; Morrondo, Patrocinio; Moreno, Teodoro; Martínez-Moreno, Alvaro

    2005-01-01

    The phenotype of the hepatic inflammatory infiltrate and hepatic lymph nodes (HLN) was analysed in lambs primarily and challenge infected with Fasciola hepatica. Group 1 was primarily and challenge infected with two doses of 200 metacercariae (mc) each and was non-treated. Trickle infection was administered to five groups: group 2 was challenge infected and non-treated; group 3 was primarily infected and non-treated; group 4 was primarily infected and treated with triclabendazole (TCBZ) at 12 weeks postinfection (wpi); group 5 was treated at 4 wpi and challenge infected and group 6 was treated at 12 wpi and challenge infected. An uninfected group was used as the control. The distribution of T cell subpopulations (CD3, CD4 and CD8), and B cells (CD79alpha, IgM, IgG) was analysed. The hepatic inflammatory infiltrate was represented mainly by CD3 and CD4 T cells, and B cells (CD79alpha, IgG). These infiltrates were more severe (P < 0.05) in primarily (group 3) or challenge (groups 2, 5 and 6) trickle infected lambs than in the group single challenge infected (group 1). Cellular changes in HLN consisted in an increase of CD4 over CD8 T cells and an increase of B cells and IgG+ plasma cells, and they were more severe in primarily and challenge trickle infected groups than in the group infected with two larger doses of mc, although significant differences were not found with respect to all challenge trickle infected groups. The strong local cellular and humoral immune responses did not protect against subsequent infections, neither in non-treated lambs (group 2) nor in lambs treated with TCBZ at 4 wpi (group 5) or 12 wpi (group 6).

  2. Advanced thermally stable jet fuels

    Energy Technology Data Exchange (ETDEWEB)

    Schobert, H.H.

    1999-01-31

    The Pennsylvania State University program in advanced thermally stable coal-based jet fuels has five broad objectives: (1) Development of mechanisms of degradation and solids formation; (2) Quantitative measurement of growth of sub-micrometer and micrometer-sized particles suspended in fuels during thermal stressing; (3) Characterization of carbonaceous deposits by various instrumental and microscopic methods; (4) Elucidation of the role of additives in retarding the formation of carbonaceous solids; (5) Assessment of the potential of production of high yields of cycloalkanes by direct liquefaction of coal. Future high-Mach aircraft will place severe thermal demands on jet fuels, requiring the development of novel, hybrid fuel mixtures capable of withstanding temperatures in the range of 400--500 C. In the new aircraft, jet fuel will serve as both an energy source and a heat sink for cooling the airframe, engine, and system components. The ultimate development of such advanced fuels requires a thorough understanding of the thermal decomposition behavior of jet fuels under supercritical conditions. Considering that jet fuels consist of hundreds of compounds, this task must begin with a study of the thermal degradation behavior of select model compounds under supercritical conditions. The research performed by The Pennsylvania State University was focused on five major tasks that reflect the objectives stated above: Task 1: Investigation of the Quantitative Degradation of Fuels; Task 2: Investigation of Incipient Deposition; Task 3: Characterization of Solid Gums, Sediments, and Carbonaceous Deposits; Task 4: Coal-Based Fuel Stabilization Studies; and Task 5: Exploratory Studies on the Direct Conversion of Coal to High Quality Jet Fuels. The major findings of each of these tasks are presented in this executive summary. A description of the sub-tasks performed under each of these tasks and the findings of those studies are provided in the remainder of this volume

  3. Template-directed synthesis of kinetically and thermodynamically stable molecular necklace using ring closing metathesis.

    Science.gov (United States)

    Dasgupta, Suvankar; Wu, Jishan

    2011-05-07

    We report the template-directed synthesis of a well-defined, kinetically stable [5]molecular necklace with dialkylammonium ion (R(2)NH(2)(+)) as recognition site and DB24C8 as macrocycle. A thread containing four dialkylammonium ions with olefin at both ends was first synthesized and then subjected to threading with an excess amount of DB24C8 to form pseudo[5]rotaxane, which in situ undergoes ring closing metathesis at the termini with second generation Grubbs catalyst to yield the desired [5]molecular necklace. The successful synthesis of [5]molecular necklace is mainly attributed to the self-assembly and dynamic covalent chemistry which allows the formation of thermodynamically most stable product. The self-assembly of the DB24C8 ring onto the recognition site known as templating effect was driven by noncovalent stabilizing interactions like [N(+)-H···O], [C-H···O] hydrogen bonds as well as [π···π] interactions which is facilitated in non-polar solvents. The reversible nature of olefin metathesis reaction makes it suitable for dynamic covalent chemistry since proof-reading and error-checking operates until it generates thermodynamically the most stable interlocked molecule. Riding on the success of [5]molecular necklace, we went a step further and attempted to synthesize [7]molecular necklace using the same protocol. This led to the synthesis of another thread with olefin at both ends but having six dibenzylammonium ions along the thread. However, the extremely poor solubility of this thread containing six secondary ammonium ions limits the self-assembly process even after we replaced the typical PF(6)(-) counter anion with a more lipophilic BPh(4)(-) anion. Although the poor solubility of the thread remains the bottleneck for making higher order molecular necklaces yet this approach of "threading-followed-by-ring-closing-metathesis" for the first time produces kinetically and thermodynamically stable, well-defined, homogeneous molecular necklace which

  4. Population Games, Stable Games, and Passivity

    Directory of Open Access Journals (Sweden)

    Michael J. Fox

    2013-10-01

    Full Text Available The class of “stable games”, introduced by Hofbauer and Sandholm in 2009, has the attractive property of admitting global convergence to equilibria under many evolutionary dynamics. We show that stable games can be identified as a special case of the feedback-system-theoretic notion of a “passive” dynamical system. Motivated by this observation, we develop a notion of passivity for evolutionary dynamics that complements the definition of the class of stable games. Since interconnections of passive dynamical systems exhibit stable behavior, we can make conclusions about passive evolutionary dynamics coupled with stable games. We show how established evolutionary dynamics qualify as passive dynamical systems. Moreover, we exploit the flexibility of the definition of passive dynamical systems to analyze generalizations of stable games and evolutionary dynamics that include forecasting heuristics as well as certain games with memory.

  5. Nonpolar solvation dynamics for a nonpolar solute in room ...

    Indian Academy of Sciences (India)

    Sandipa Indra

    2018-01-30

    Jan 30, 2018 ... a cubic box; the configuration is generated using PACK-. MOL package.59 The required box length is calculated from the previously simulated equilibrium density of this RTIL. (4.705 mol ...... Saven J S and Skinner J L 1993 A molecular theory of the line shape: Inhomogeneous and homogeneous electronic ...

  6. Nonpolar solvation dynamics for a nonpolar solute in room ...

    Indian Academy of Sciences (India)

    Sandipa Indra

    2018-01-30

    Jan 30, 2018 ... work.60 Detailed description of the potential form including the meaning of the terms is presented ... tion 3.0 ns starting from the end point of the previous 1 ns equilibrium trajectory. The first nonequilibrium ...... Measurements of Polar Solvation. Dynamics: Coumarin 153 Revisited J. Phys. Chem. 99. 17311.

  7. Nanoparticles affect PCR primarily via surface interactions with PCR components: using amino-modified silica-coated magnetic nanoparticles as a main model

    Science.gov (United States)

    Nanomaterials have been widely reported to affect the polymerase chain reaction (PCR). However, many studies in which these effects were observed were not comprehensive, and many of the proposed mechanisms have been primarily speculative. In this work, we used amino-modified silica-coated magnetic n...

  8. Gas phase thermal diffusion of stable isotopes

    International Nuclear Information System (INIS)

    Eck, C.F.

    1979-01-01

    The separation of stable isotopes at Mound Facility is reviewed from a historical perspective. The historical development of thermal diffusion from a laboratory process to a separation facility that handles all the noble gases is described. In addition, elementary thermal diffusion theory and elementary cascade theory are presented along with a brief review of the uses of stable isotopes

  9. physico-chemical and stable isotopes

    African Journals Online (AJOL)

    This paper details the mineralogical, chemical and stable isotope abundances of calcrete in the Letlhakeng fossil valley. The stable isotope abundances (O and C) of calcretes yielded some values which were tested against the nature of the calcretes – pedogenic or groundwater type. The Kgalagadi (Kalahari) is a vast ...

  10. Modelling stable atmospheric boundary layers over snow

    NARCIS (Netherlands)

    Sterk, H.A.M.

    2015-01-01

    Thesis entitled:

    Modelling Stable Atmospheric Boundary Layers over Snow

    H.A.M. Sterk

    Wageningen, 29th of April, 2015

    Summary

    The emphasis of this thesis is on the understanding and forecasting of the Stable Boundary Layer (SBL) over snow-covered surfaces. SBLs

  11. Modelling stable atmospheric boundary layers over snow

    NARCIS (Netherlands)

    Sterk, H.A.M.

    2015-01-01

    Thesis entitled: Modelling Stable Atmospheric Boundary Layers over Snow H.A.M. Sterk Wageningen, 29th of April, 2015 Summary The emphasis of this thesis is on the understanding and forecasting of the Stable Boundary Layer (SBL) over snow-covered surfaces. SBLs typically form at night and in polar

  12. Stable Agrobacterium -mediated transformation of the halophytic ...

    African Journals Online (AJOL)

    Stable Agrobacterium-mediated transformation of the halophytic Leymus chinensis (Trin.) Yan-Lin Sun, Soon-Kwan Hong. Abstract. In this study, an efficient procedure for stable Agrobacterium-mediated transformation of Leymus chinensis (Trin.) was established. Agrobacterium tumefaciens strain EHA105, harboring a ...

  13. Structure of acid-stable carmine.

    Science.gov (United States)

    Sugimoto, Naoki; Kawasaki, Yoko; Sato, Kyoko; Aoki, Hiromitsu; Ichi, Takahito; Koda, Takatoshi; Yamazaki, Takeshi; Maitani, Tamio

    2002-02-01

    Acid-stable carmine has recently been distributed in the U.S. market because of its good acid stability, but it is not permitted in Japan. We analyzed and determined the structure of the major pigment in acid-stable carmine, in order to establish an analytical method for it. Carminic acid was transformed into a different type of pigment, named acid-stable carmine, through amination when heated in ammonia solution. The features of the structure were clarified using a model compound, purpurin, in which the orientation of hydroxyl groups on the A ring of the anthraquinone skeleton is the same as that of carminic acid. By spectroscopic means and the synthesis of acid-stable carmine and purpurin derivatives, the structure of the major pigment in acid-stable carmine was established as 4-aminocarminic acid, a novel compound.

  14. Stable Fly, (L., Dispersal and Governing Factors

    Directory of Open Access Journals (Sweden)

    Allan T. Showler

    2015-01-01

    Full Text Available Although the movement of stable fly, Stomoxys calcitrans (L., has been studied, its extent and significance has been uncertain. On a local scale (13 km is mainly wind-driven by weather fronts that carry stable flies from inland farm areas for up to 225 km to beaches of northwestern Florida and Lake Superior. Stable flies can reproduce for a short time each year in washed-up sea grass, but the beaches are not conducive to establishment. Such movement is passive and does not appear to be advantageous to stable fly's survival. On a regional scale, stable flies exhibit little genetic differentiation, and on the global scale, while there might be more than one “lineage”, the species is nevertheless considered to be panmictic. Population expansion across much of the globe likely occurred from the late Pleistocene to the early Holocene in association with the spread of domesticated nomad livestock and particularly with more sedentary, penned livestock.

  15. Characterization of nonpolar a-plane GaN epi-layers grown on high-density patterned r-plane sapphire substrates

    Science.gov (United States)

    Jinno, Daiki; Otsuki, Shunya; Sugimori, Shogo; Daicho, Hisayoshi; Iwaya, Motoaki; Takeuchi, Tetsuya; Kamiyama, Satoshi; Akasaki, Isamu

    2018-02-01

    To reduce the number of threading dislocations (TDs) in nonpolar a-plane GaN (a-GaN) epi-layers grown on flat r-plane sapphire substrates (r-FSS), we investigated the effects on the crystalline quality of the a-GaN epi-layers of high-density patterned r-plane sapphire substrates (r-HPSS), the patterns of which were placed at intervals of several hundred nanometers. Two types of r-HPSS, the patterns of which had diameters and heights on the order of several hundred nanometers (r-NHPSS) or several micrometers (r-MHPSS), were prepared with conventional r-FSS. The effect of these r-HPSS on the a-GaN epi-layers was demonstrated by evaluating the surface morphology and the crystalline quality of the epi-layers. The surfaces of the a-GaN epi-layer grown on r-FSS and r-NHPSS were pit-free and mirror-like, whereas the surface of the a-GaN epi-layer grown on r-MHPSS was very rough due to the large, irregular GaN islands that grew on the patterns, mainly at the initial growth stage. The crystalline quality of the a-GaN epi-layer grown on r-NHPSS was better than that of the a-GaN epi-layer grown on r-FSS. We confirmed that there were fewer TDs in the a-GaN epi-layer grown on r-NHPSS than there were in the a-GaN epi-layer grown on r-FSS. The TDs propagating to the surface in a-GaN epi-layer grown on r-NHPSS were mainly generated on the flat sapphire regions between the patterns. Interestingly, it was also found that the TDs that propagated to the surface concentrated with a periodic pitch along the c-axis direction. The TD densities of a-GaN epi-layers grown on r-FSS and r-NHPSS were estimated to be approximately 5.0 × 1010 and 1.5 × 109 cm-2, respectively. This knowledge will contribute to the further development of a-GaN epi-layers for high-performance devices.

  16. Energy efficiency for the removal of non-polar pollutants during ultraviolet irradiation, visible light photocatalysis and ozonation of a wastewater effluent.

    Science.gov (United States)

    Santiago-Morales, Javier; Gómez, María José; Herrera-López, Sonia; Fernández-Alba, Amadeo R; García-Calvo, Eloy; Rosal, Roberto

    2013-10-01

    This study aims to assess the removal of a set of non-polar pollutants in biologically treated wastewater using ozonation, ultraviolet (UV 254 nm low pressure mercury lamp) and visible light (Xe-arc lamp) irradiation as well as visible light photocatalysis using Ce-doped TiO2. The compounds tracked include UV filters, synthetic musks, herbicides, insecticides, antiseptics and polyaromatic hydrocarbons. Raw wastewater and treated samples were analyzed using stir-bar sorptive extraction coupled with comprehensive two-dimensional gas chromatography (SBSE-CG × GC-TOF-MS). Ozone treatment could remove most pollutants with a global efficiency of over 95% for 209 μM ozone dosage. UV irradiation reduced the total concentration of the sixteen pollutants tested by an average of 63% with high removal of the sunscreen 2-ethylhexyl trans-4-methoxycinnamate (EHMC), the synthetic musk 7-acetyl-1,1,3,4,4,6-hexamethyltetrahydronaphthalene (tonalide, AHTN) and several herbicides. Visible light Ce-TiO2 photocatalysis reached ~70% overall removal with particularly high efficiency for synthetic musks. In terms of power usage efficiency expressed as nmol kJ(-1), the results showed that ozonation was by far the most efficient process, ten-fold over Xe/Ce-TiO2 visible light photocatalysis, the latter being in turn considerably more efficient than UV irradiation. In all cases the efficiency decreased along the treatments due to the lower reaction rate at lower pollutant concentration. The use of photocatalysis greatly improved the efficiency of visible light irradiation. The collector area per order decreased from 9.14 ± 5.11 m(2) m(-3) order(-1) for visible light irradiation to 0.16 ± 0.03 m(2) m(-3) order(-1) for Ce-TiO2 photocatalysis. The toxicity of treated wastewater was assessed using the green alga Pseudokirchneriella subcapitata. Ozonation reduced the toxicity of treated wastewater, while UV irradiation and visible light photocatalysis limited by 20-25% the algal growth due to

  17. Dormancy and Impotency of Cocklebur Seeds VIII. : Lack of Germination Responsiveness in Primarily Dormant Seeds to Cyanide, Azide, Anoxia and Chilling

    OpenAIRE

    Yohji, Esashi; Hiromitsu, Komatsu; Nobuyori, Ishihara; Kimiharu, Ishizawa; Department of Biological Science, Tohoku University; Department of Biological Science, Tohoku University; Department of Biological Science, Tohoku University; Department of Biological Science, Tohoku University

    1982-01-01

    Germination responsiveness to KCN, NaN_3, chilling or anoxia and respiration activity was compared between non-after-ripened and after-ripened upper cocklebur (Xanthium pennsylvanicum Wallr.) seeds. The latter, coat-imposed dormant seeds, could germinate in response to the above chemicals and conditions, whereas the former, primarily dormant seeds, could not respond. There was little difference in the respiratory properties of both types of seeds.

  18. Stable Organic Neutral Diradical via Reversible Coordination.

    Science.gov (United States)

    Lu, Zhenpin; Quanz, Henrik; Burghaus, Olaf; Hofmann, Jonas; Logemann, Christian; Beeck, Sebastian; Schreiner, Peter R; Wegner, Hermann A

    2017-12-27

    We report the formation of a stable neutral diboron diradical simply by coordination of an aromatic dinitrogen compound to an ortho-phenyldiborane. This process is reversible upon addition of pyridine. The diradical species is stable above 200 °C. Computations are consistent with an open-shell triplet diradical with a very small open-shell singlet-triplet energy gap that is indicative of the electronic disjointness of the two radical sites. This opens a new way of generating stable radicals with fascinating electronic properties useful for a large variety of applications.

  19. Stable, Fluorescent Polymethylmethacrylate Particles for the Long-Term Observation of Slow Colloidal Dynamics.

    Science.gov (United States)

    Kodger, Thomas E; Lu, Peter J; Wiseman, G Reid; Weitz, David A

    2017-06-27

    Suspensions of solid micron-scale colloidal particles in liquid solvents are a foundational model system used to explore a wide range of phase transitions, including crystallization, gelation, spinodal decomposition, and the glass transition. One of the most commonly used systems for these investigations is the fluorescent spherical particles of polymethylmethacrylate (PMMA) suspended in a mixture of nonpolar solvents that match the density and the refractive index of the particles to minimize sedimentation and scattering. However, the particles can swell in these solvents, changing their size and density, and may leak the fluorescent dye over days to weeks; this constrains the exploration of slow and kinetically limited processes, such as near-boundary phase separation or the glass transition. In this paper, we produce PMMA colloidal particles that employ polymerizable and photostable cyanine-based fluorescent monomers spanning the range of visible wavelengths and a polymeric stabilizer prepared from polydimethylsiloxane, PDMS-graft-PMMA. Using microcalorimetry, we characterize the thermodynamics of an accelerated equilibration process for these dispersions in the buoyancy- and refractive-index-matching solvents. We use confocal differential dynamic microscopy to demonstrate that they behave as hard spheres. The suspended particles are stable for months to years, maintaining fixed particle size and density, and do not leak dye. Thus, these particles enable longer term experiments than may have been possible earlier; we demonstrate this by observing spinodal decomposition in a mixture of these particles with a depletant polymer in the microgravity environment of the International Space Station. Using fluorescence microscopy, we observe coarsening over several months and measure the growth of the characteristic length scale to be a fraction of a picometer per second; this rate is among the slowest observed in a phase-separating system. Our protocols should

  20. Stable Isotope Group 1983 progress report

    International Nuclear Information System (INIS)

    Stewart, M.K.

    1984-06-01

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and related fields, and mass spectrometer instrumentation, during 1983, is described

  1. Stable Isotope Group 1982 progress report

    International Nuclear Information System (INIS)

    Stewart, M.K.

    1983-06-01

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences during 1982, in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and mass spectrometer instrumentation, is described

  2. Bartolome Island, Galapagos Stable Oxygen Calibration Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Galapagos Coral Stable Oxygen Calibration Data. Sites: Bartolome Island: 0 deg, 17'S, 90 deg 33' W. Champion Island: 1 deg, 15'S, 90 deg, 05' W. Urvina Bay (Isabela...

  3. Allan Hills Stable Water Isotopes, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes stable water isotope values at 10 m resolution along an approximately 5 km transect through the main icefield of the Allan Hills Blue Ice...

  4. Applications of stable isotopes in clinical pharmacology

    Science.gov (United States)

    Schellekens, Reinout C A; Stellaard, Frans; Woerdenbag, Herman J; Frijlink, Henderik W; Kosterink, Jos G W

    2011-01-01

    This review aims to present an overview of the application of stable isotope technology in clinical pharmacology. Three main categories of stable isotope technology can be distinguished in clinical pharmacology. Firstly, it is applied in the assessment of drug pharmacology to determine the pharmacokinetic profile or mode of action of a drug substance. Secondly, stable isotopes may be used for the assessment of drug products or drug delivery systems by determination of parameters such as the bioavailability or the release profile. Thirdly, patients may be assessed in relation to patient-specific drug treatment; this concept is often called personalized medicine. In this article, the application of stable isotope technology in the aforementioned three areas is reviewed, with emphasis on developments over the past 25 years. The applications are illustrated with examples from clinical studies in humans. PMID:21801197

  5. Tannaka duality and stable infinity-categories

    OpenAIRE

    Iwanari, Isamu

    2014-01-01

    We introduce the notion of fine tannakian infinity-categories and prove Tannaka duality results for symmetric monoidal stable infinity-categories over a field of characteristic zero. We also discuss several examples.

  6. On Stable Marriages and Greedy Matchings

    Energy Technology Data Exchange (ETDEWEB)

    Manne, Fredrik; Naim, Md; Lerring, Hakon; Halappanavar, Mahantesh

    2016-12-11

    Research on stable marriage problems has a long and mathematically rigorous history, while that of exploiting greedy matchings in combinatorial scientific computing is a younger and less developed research field. In this paper we consider the relationships between these two areas. In particular we show that several problems related to computing greedy matchings can be formulated as stable marriage problems and as a consequence several recently proposed algorithms for computing greedy matchings are in fact special cases of well known algorithms for the stable marriage problem. However, in terms of implementations and practical scalable solutions on modern hardware, the greedy matching community has made considerable progress. We show that due to the strong relationship between these two fields many of these results are also applicable for solving stable marriage problems.

  7. The Reactivity of Stable Metallacyclobutenes and Vinylcarbenes

    OpenAIRE

    Holland, Ryan Lynn

    2016-01-01

    Chapter 1. Historical Development of Stable Metallacyclobutenes Fred Tebbe and co-workers synthesized the first stable metallacyclobutene complexes in the late 1970’s by treatment of an intermediate titanium methylene species – later popularized as the “Tebbe reagent” – with acetylenes. Robert Grubbs at Caltech further studied this system, using it to detail a degenerate metathesis reaction and to isolate a metallacyclobutane complex – which was implicated in the emerging field of alkene meta...

  8. Stable atomic hydrogen: Polarized atomic beam source

    International Nuclear Information System (INIS)

    Niinikoski, T.O.; Penttilae, S.; Rieubland, J.M.; Rijllart, A.

    1984-01-01

    We have carried out experiments with stable atomic hydrogen with a view to possible applications in polarized targets or polarized atomic beam sources. Recent results from the stabilization apparatus are described. The first stable atomic hydrogen beam source based on the microwave extraction method (which is being tested ) is presented. The effect of the stabilized hydrogen gas density on the properties of the source is discussed. (orig.)

  9. Selective area growth of AlN/GaN nanocolumns on (0001) and (11-22) GaN/sapphire for semi-polar and non-polar AlN pseudo-templates

    Science.gov (United States)

    Bengoechea-Encabo, A.; Albert, S.; Müller, M.; Xie, M.–Y.; Veit, P.; Bertram, F.; Sanchez-Garcia, M. A.; Zúñiga-Pérez, J.; de Mierry, P.; Christen, J.; Calleja, E.

    2017-09-01

    Despite the strong interest in optoelectronic devices working in the deep ultraviolet range, no suitable low cost, large-area, high-quality AlN substrates have been available up to now. The aim of this work is the selective area growth of AlN nanocolumns by plasma assisted molecular beam epitaxy on polar (0001) and semi-polar (11-22) GaN/sapphire templates. The resulting AlN nanocolumns are vertically oriented with semi-polar {1-103} top facets when grown on (0001) GaN/sapphire, or oriented at 58° from the template normal and exposing {1-100} non-polar top facets when growing on (11-22) GaN/sapphire, in both cases reaching filling factors ≥80%. In these kinds of arrays each nanostructure could function as a building block for an individual nano-device or, due to the large filling factor values, the overall array top surfaces could be seen as a quasi (semi-polar or non-polar) AlN pseudo-template.

  10. Local Search Approaches in Stable Matching Problems

    Directory of Open Access Journals (Sweden)

    Toby Walsh

    2013-10-01

    Full Text Available The stable marriage (SM problem has a wide variety of practical applications, ranging from matching resident doctors to hospitals, to matching students to schools or, more generally, to any two-sided market. In the classical formulation, n men and n women express their preferences (via a strict total order over the members of the other sex. Solving an SM problem means finding a stable marriage where stability is an envy-free notion: no man and woman who are not married to each other would both prefer each other to their partners or to being single. We consider both the classical stable marriage problem and one of its useful variations (denoted SMTI (Stable Marriage with Ties and Incomplete lists where the men and women express their preferences in the form of an incomplete preference list with ties over a subset of the members of the other sex. Matchings are permitted only with people who appear in these preference lists, and we try to find a stable matching that marries as many people as possible. Whilst the SM problem is polynomial to solve, the SMTI problem is NP-hard. We propose to tackle both problems via a local search approach, which exploits properties of the problems to reduce the size of the neighborhood and to make local moves efficiently. We empirically evaluate our algorithm for SM problems by measuring its runtime behavior and its ability to sample the lattice of all possible stable marriages. We evaluate our algorithm for SMTI problems in terms of both its runtime behavior and its ability to find a maximum cardinality stable marriage. Experimental results suggest that for SM problems, the number of steps of our algorithm grows only as O(n log(n, and that it samples very well the set of all stable marriages. It is thus a fair and efficient approach to generate stable marriages. Furthermore, our approach for SMTI problems is able to solve large problems, quickly returning stable matchings of large and often optimal size, despite the

  11. Evaluating a County-Sponsored Social Marketing Campaign to Increase Mothers’ Initiation of HPV Vaccine for their Pre-teen Daughters in a Primarily Rural Area

    Science.gov (United States)

    Cates, Joan R.; Shafer, Autumn; Diehl, Sandra J.; Deal, Allison M.

    2011-01-01

    Routine vaccination against human papillomavirus (HPV), the main cause of cervical cancer, is recommended for 11–12 year old girls, yet vaccine uptake is low. This study evaluates a social marketing campaign initiated by 13 North Carolina counties to raise awareness among parents and reduce barriers to accessing the vaccine in a primarily rural area. The 3-month campaign targeted mothers of girls ages 11–12 and healthcare practices serving pre-teen girls in four counties. Principles of social marketing were: product (recommended vaccine against HPV), price (cost, perception of safety and efficacy, and access), promotion (posters, brochures, website, news releases, doctor’s recommendation), and place (doctors’ offices, retail outlets). We analyzed (1) website traffic, hotline calls, and media placement; (2) cross-sectional surveys of mothers and providers; and (3) HPV immunization rates in intervention versus non-intervention counties. Of respondent mothers (n=225), 82% heard or saw campaign messages or materials. Of respondent providers (n=35), 94% used campaign brochures regularly or occasionally in conversations with parents. HPV vaccination rates within six months of campaign launch were 2% higher for 9–13 year old girls in two of the four intervention counties compared to 96 non-intervention counties. This evaluation supports campaign use in other primarily rural and underserved areas. PMID:21804767

  12. Evaluating a County-Sponsored Social Marketing Campaign to Increase Mothers' Initiation of HPV Vaccine for their Pre-teen Daughters in a Primarily Rural Area.

    Science.gov (United States)

    Cates, Joan R; Shafer, Autumn; Diehl, Sandra J; Deal, Allison M

    2011-01-01

    Routine vaccination against human papillomavirus (HPV), the main cause of cervical cancer, is recommended for 11-12 year old girls, yet vaccine uptake is low. This study evaluates a social marketing campaign initiated by 13 North Carolina counties to raise awareness among parents and reduce barriers to accessing the vaccine in a primarily rural area. The 3-month campaign targeted mothers of girls ages 11-12 and healthcare practices serving pre-teen girls in four counties. Principles of social marketing were: product (recommended vaccine against HPV), price (cost, perception of safety and efficacy, and access), promotion (posters, brochures, website, news releases, doctor's recommendation), and place (doctors' offices, retail outlets). We analyzed (1) website traffic, hotline calls, and media placement; (2) cross-sectional surveys of mothers and providers; and (3) HPV immunization rates in intervention versus non-intervention counties. Of respondent mothers (n=225), 82% heard or saw campaign messages or materials. Of respondent providers (n=35), 94% used campaign brochures regularly or occasionally in conversations with parents. HPV vaccination rates within six months of campaign launch were 2% higher for 9-13 year old girls in two of the four intervention counties compared to 96 non-intervention counties. This evaluation supports campaign use in other primarily rural and underserved areas.

  13. A randomized trial of a DWI intervention program for first offenders: intervention outcomes and interactions with antisocial personality disorder among a primarily American-Indian sample.

    Science.gov (United States)

    Woodall, W Gill; Delaney, Harold D; Kunitz, Stephen J; Westerberg, Verner S; Zhao, Hongwei

    2007-06-01

    Randomized trial evidence on the effectiveness of incarceration and treatment of first-time driving while intoxicated (DWI) offenders who are primarily American Indian has yet to be reported in the literature on DWI prevention. Further, research has confirmed the association of antisocial personality disorder (ASPD) with problems with alcohol including DWI. A randomized clinical trial was conducted, in conjunction with 28 days of incarceration, of a treatment program incorporating motivational interviewing principles for first-time DWI offenders. The sample of 305 offenders including 52 diagnosed as ASPD by the Diagnostic Interview Schedule were assessed before assignment to conditions and at 6, 12, and 24 months after discharge. Self-reported frequency of drinking and driving as well as various measures of drinking over the preceding 90 days were available at all assessments for 244 participants. Further, DWI rearrest data for 274 participants were available for analysis. Participants randomized to receive the first offender incarceration and treatment program reported greater reductions in alcohol consumption from baseline levels when compared with participants who were only incarcerated. Antisocial personality disorder participants reported heavier and more frequent drinking but showed significantly greater declines in drinking from intake to posttreatment assessments. Further, the treatment resulted in larger effects relative to the control on ASPD than non-ASPD participants. Nonconfrontational treatment may significantly enhance outcomes for DWI offenders with ASPD when delivered in an incarcerated setting, and in the present study, such effects were found in a primarily American-Indian sample.

  14. Stable chaos in fluctuation driven neural circuits

    International Nuclear Information System (INIS)

    Angulo-Garcia, David; Torcini, Alessandro

    2014-01-01

    Highlights: • Nonlinear instabilities in fluctuation driven (balanced) neural circuits are studied. • Balanced networks display chaos and stable phases at different post-synaptic widths. • Linear instabilities coexists with nonlinear ones in the chaotic regime. • Erratic motion appears also in linearly stable phase due to stable chaos. - Abstract: We study the dynamical stability of pulse coupled networks of leaky integrate-and-fire neurons against infinitesimal and finite perturbations. In particular, we compare mean versus fluctuations driven networks, the former (latter) is realized by considering purely excitatory (inhibitory) sparse neural circuits. In the excitatory case the instabilities of the system can be completely captured by an usual linear stability (Lyapunov) analysis, whereas the inhibitory networks can display the coexistence of linear and nonlinear instabilities. The nonlinear effects are associated to finite amplitude instabilities, which have been characterized in terms of suitable indicators. For inhibitory coupling one observes a transition from chaotic to non chaotic dynamics by decreasing the pulse-width. For sufficiently fast synapses the system, despite showing an erratic evolution, is linearly stable, thus representing a prototypical example of stable chaos

  15. Metabolic studies in man using stable isotopes

    International Nuclear Information System (INIS)

    Faust, H.; Jung, K.; Krumbiegel, P.

    1993-01-01

    In this project, stable isotope compounds and stable isotope pharmaceuticals were used (with emphasis on the application of 15 N) to study several aspects of nitrogen metabolism in man. Of the many methods available, the 15 N stable isotope tracer technique holds a special position because the methodology for application and nitrogen isotope analysis is proven and reliable. Valid routine methods using 15 N analysis by emission spectrometry have been demonstrated. Several methods for the preparation of biological material were developed during our participation in the Coordinated Research Programme. In these studies, direct procedures (i.e. use of diluted urine as a samples without chemical preparation) or rapid isolation methods were favoured. Within the scope of the Analytical Quality Control Service (AQCS) enriched stable isotope reference materials for medical and biological studies were prepared and are now available through the International Atomic Energy Agency. The materials are of special importance as the increasing application of stable isotopes as tracers in medical, biological and agricultural studies has focused interest on reliable measurements of biological material of different origin. 24 refs

  16. Temperature and Humidity Control in Livestock Stables

    DEFF Research Database (Denmark)

    Hansen, Michael; Andersen, Palle; Nielsen, Kirsten M.

    2010-01-01

    The paper describes temperature and humidity control of a livestock stable. It is important to have a correct air flow pattern in the livestock stable in order to achieve proper temperature and humidity control as well as to avoid draught. In the investigated livestock stable the air flow...... is controlled using wall mounted ventilation flaps. In the paper an algorithm for air flow control is presented meeting the needs for temperature and humidity while taking the air flow pattern in consideration. To obtain simple and realisable controllers a model based control design method is applied....... In the design dynamic models for temperature and humidity are very important elements and effort is put into deriving and testing the models. It turns out that non-linearities are dominating in both models making feedback linearization the natural design method. The air controller as well as the temperature...

  17. On some topological properties of stable measures

    DEFF Research Database (Denmark)

    Nielsen, Carsten Krabbe

    1996-01-01

    Summary The paper shows that the set of stable probability measures and the set of Rational Beliefs relative to a given stationary measure are closed in the strong topology, but not closed in the topology of weak convergence. However, subsets of the set of stable probability measures which...... are characterized by uniformity of convergence of the empirical distribution are closed in the topology of weak convergence. It is demonstrated that such subsets exist. In particular, there is an increasing sequence of sets of SIDS measures who's union is the set of all SIDS measures generated by a particular...... system and such that each subset consists of stable measures. The uniformity requirement has a natural interpretation in terms of plausibility of Rational Beliefs...

  18. Concentration of stable elements in food products

    Energy Technology Data Exchange (ETDEWEB)

    Montford, M.A.; Shank, K.E.; Hendricks, C.; Oakes, T.W.

    1980-01-01

    Food samples were taken from commercial markets and analyzed for stable element content. The concentrations of most stable elements (Ag, Al, As, Au, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Cu, Fe, Hf, I, K, La, Mg, Mn, Mo, Na, Rb, Sb, Sc, Se, Sr, Ta, Th, Ti, V, Zn, Zr) were determined using multiple-element neutron activation analysis, while the concentrations of other elements (Cd, Hg, Ni, Pb) were determined using atomic absorption. The relevance of the concentrations found are noted in relation to other literature values. An earlier study was extended to include the determination of the concentration of stable elements in home-grown products in the vicinity of the Oak Ridge National Laboratory. Comparisons between the commercial and local food-stuff values are discussed.

  19. Faster and Simpler Approximation of Stable Matchings

    Directory of Open Access Journals (Sweden)

    Katarzyna Paluch

    2014-04-01

    Full Text Available We give a 3 2 -approximation algorithm for finding stable matchings that runs in O(m time. The previous most well-known algorithm, by McDermid, has the same approximation ratio but runs in O(n3/2m time, where n denotes the number of people andm is the total length of the preference lists in a given instance. In addition, the algorithm and the analysis are much simpler. We also give the extension of the algorithm for computing stable many-to-many matchings.

  20. Stable isotopes in Lithuanian bioarcheological material

    Science.gov (United States)

    Skipityte, Raminta; Jankauskas, Rimantas; Remeikis, Vidmantas

    2015-04-01

    Investigation of bioarcheological material of ancient human populations allows us to understand the subsistence behavior associated with various adaptations to the environment. Feeding habits are essential to the survival and growth of ancient populations. Stable isotope analysis is accepted tool in paleodiet (Schutkowski et al, 1999) and paleoenvironmental (Zernitskaya et al, 2014) studies. However, stable isotopes can be useful not only in investigating human feeding habits but also in describing social and cultural structure of the past populations (Le Huray and Schutkowski, 2005). Only few stable isotope investigations have been performed before in Lithuanian region suggesting a quite uniform diet between males and females and protein intake from freshwater fish and animal protein. Previously, stable isotope analysis has only been used to study a Stone Age population however, more recently studies have been conducted on Iron Age and Late medieval samples (Jacobs et al, 2009). Anyway, there was a need for more precise examination. Stable isotope analysis were performed on human bone collagen and apatite samples in this study. Data represented various ages (from 5-7th cent. to 18th cent.). Stable carbon and nitrogen isotope analysis on medieval populations indicated that individuals in studied sites in Lithuania were almost exclusively consuming C3 plants, C3 fed terrestrial animals, and some freshwater resources. Current investigation demonstrated social differences between elites and country people and is promising in paleodietary and daily life reconstruction. Acknowledgement I thank prof. dr. G. Grupe, Director of the Anthropological and Palaeoanatomical State Collection in Munich for providing the opportunity to work in her laboratory. The part of this work was funded by DAAD. Antanaitis-Jacobs, Indre, et al. "Diet in early Lithuanian prehistory and the new stable isotope evidence." Archaeologia Baltica 12 (2009): 12-30. Le Huray, Jonathan D., and Holger

  1. Bordism, stable homotopy and adams spectral sequences

    CERN Document Server

    Kochman, Stanley O

    1996-01-01

    This book is a compilation of lecture notes that were prepared for the graduate course "Adams Spectral Sequences and Stable Homotopy Theory" given at The Fields Institute during the fall of 1995. The aim of this volume is to prepare students with a knowledge of elementary algebraic topology to study recent developments in stable homotopy theory, such as the nilpotence and periodicity theorems. Suitable as a text for an intermediate course in algebraic topology, this book provides a direct exposition of the basic concepts of bordism, characteristic classes, Adams spectral sequences, Brown-Peter

  2. Modelling stable water isotopes: Status and perspectives

    Directory of Open Access Journals (Sweden)

    Werner M.

    2010-12-01

    Full Text Available Modelling of stable water isotopes H2 18O and HDO within various parts of the Earth’s hydrological cycle has clearly improved our understanding of the interplay between climatic variations and related isotope fractionation processes. In this article key principles and major research results of stable water isotope modelling studies are described. Emphasis is put on research work using explicit isotope diagnostics within general circulation models as this highly complex model setup bears many resemblances with studies using simpler isotope modelling approaches.

  3. Engaging Undergraduates in a Unique Neuroscience Research Opportunity: A Collaborative Research Experience Between a Primarily Undergraduate Institution (PUI) and a Major Research Institution.

    Science.gov (United States)

    Kreitzer, Matthew A; Malchow, Robert P

    2013-01-01

    This report describes a unique undergraduate research and teaching collaboration between investigators at two institutions, one a relatively small, primarily undergraduate institution and the other a large, urban research-intensive university. The program incorporates three major facets. First, undergraduates participate in a weekly collaborative lab meeting involving instructors from both institutions and held via remote video. Student-led discussions and presentations dominate these meetings, and the unique format promotes novel interactions between students and instructors. Second, students carry out investigative studies centered on understanding the role extracellular pH dynamics play in regulating neuronal processing. Students carry out studies on isolated neurons and glia throughout the fall and spring semesters, and primarily use a noninvasive electrophysiological technique, termed self-referencing, for extracellular pH measurements. The technique is relatively simple and readily learned and employed by undergraduates, while still being powerful enough to provide novel and meaningful research results. The research component is expanded for several students each summer who are selected to participate in summer research with both PIs and graduate students at the major research institution. Finally results gathered during the year and over the summer are disseminated at institutional symposia, undergraduate neuroscience symposia, national society meetings, and in submitted journal manuscripts. Preliminary observations and findings over three years support the aim of this research experience; to create a productive environment that facilitates deep-level understanding of neurophysiological concepts at the undergraduate level and promotes intellectual development while cultivating an excitement for scientific inquiry in the present and future.

  4. Engaging Undergraduates in a Unique Neuroscience Research Opportunity: A Collaborative Research Experience Between a Primarily Undergraduate Institution (PUI) and a Major Research Institution

    Science.gov (United States)

    Kreitzer, Matthew A.; Malchow, Robert P.

    2013-01-01

    This report describes a unique undergraduate research and teaching collaboration between investigators at two institutions, one a relatively small, primarily undergraduate institution and the other a large, urban research-intensive university. The program incorporates three major facets. First, undergraduates participate in a weekly collaborative lab meeting involving instructors from both institutions and held via remote video. Student-led discussions and presentations dominate these meetings, and the unique format promotes novel interactions between students and instructors. Second, students carry out investigative studies centered on understanding the role extracellular pH dynamics play in regulating neuronal processing. Students carry out studies on isolated neurons and glia throughout the fall and spring semesters, and primarily use a noninvasive electrophysiological technique, termed self-referencing, for extracellular pH measurements. The technique is relatively simple and readily learned and employed by undergraduates, while still being powerful enough to provide novel and meaningful research results. The research component is expanded for several students each summer who are selected to participate in summer research with both PIs and graduate students at the major research institution. Finally results gathered during the year and over the summer are disseminated at institutional symposia, undergraduate neuroscience symposia, national society meetings, and in submitted journal manuscripts. Preliminary observations and findings over three years support the aim of this research experience; to create a productive environment that facilitates deep-level understanding of neurophysiological concepts at the undergraduate level and promotes intellectual development while cultivating an excitement for scientific inquiry in the present and future. PMID:24319396

  5. Stable isotopes provide insight into population structure and segregation in eastern North Atlantic sperm whales

    DEFF Research Database (Denmark)

    Borrell, Asunción; Velásquez Vacca, Adriana; Pinela, Ana M.

    2013-01-01

    highly mobile, shows indication of structuring in the eastern North Atlantic, an ocean basin in which a single population is believed to occur. To do so, we examined stable isotope values in sequential growth layer groups of teeth from individuals sampled in Denmark and NW Spain. In each layer we...... measured oxygen-isotope ratios (delta O-18) in the inorganic component (hydroxyapatite), and nitrogen and carbon isotope ratios (delta N-15: delta C-13) in the organic component (primarily collagenous). We found significant differences between Denmark and NW Spain in delta N-15 and delta O-18 values...

  6. Stable isotope analysis of dynamic lipidomics.

    Science.gov (United States)

    Brandsma, Joost; Bailey, Andrew P; Koster, Grielof; Gould, Alex P; Postle, Anthony D

    2017-08-01

    Metabolic pathway flux is a fundamental element of biological activity, which can be quantified using a variety of mass spectrometric techniques to monitor incorporation of stable isotope-labelled substrates into metabolic products. This article contrasts developments in electrospray ionisation mass spectrometry (ESI-MS) for the measurement of lipid metabolism with more established gas chromatography mass spectrometry and isotope ratio mass spectrometry methodologies. ESI-MS combined with diagnostic tandem MS/MS scans permits the sensitive and specific analysis of stable isotope-labelled substrates into intact lipid molecular species without the requirement for lipid hydrolysis and derivatisation. Such dynamic lipidomic methodologies using non-toxic stable isotopes can be readily applied to quantify lipid metabolic fluxes in clinical and metabolic studies in vivo. However, a significant current limitation is the absence of appropriate software to generate kinetic models of substrate incorporation into multiple products in the time domain. Finally, we discuss the future potential of stable isotope-mass spectrometry imaging to quantify the location as well as the extent of lipid synthesis. This article is part of a Special Issue entitled: BBALIP_Lipidomics Opinion Articles edited by Sepp Kohlwein. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Petrography, compositional characteristics and stable isotope ...

    African Journals Online (AJOL)

    Petrography, compositional characteristics and stable isotope geochemistry of the Ewekoro formation from Ibese Corehole, eastern Dahomey basin, southwestern Nigeria. ME Nton, MO ... Preserved pore types such as; intercrystaline, moldic and vuggy pores were observed as predominant conduits for fluids. The major ...

  8. petrography, compositional characteristics and stable isotope ...

    African Journals Online (AJOL)

    PROF EKWUEME

    Subsurface samples of the predominantly carbonate Ewekoro Formation, obtained from Ibese core hole within the Dahomey basin were used in this study. Investigations entail petrographic, elemental composition as well as stable isotopes (carbon and oxygen) geochemistry in order to deduce the different microfacies and ...

  9. Substitution of stable isotopes in Chlorella

    Science.gov (United States)

    Flaumenhaft, E.; Katz, J. J.; Uphaus, R. A.

    1969-01-01

    Replacement of biologically important isotopes in the alga Chlorella by corresponding heavier stable isotopes produces increasingly greater deviations from the normal cell size and changes the quality and distribution of certain cellular components. The usefulness of isotopically altered organisms increases interest in the study of such permuted organisms.

  10. Champion Island, Galapagos Stable Oxygen Calibration Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Galapagos Coral Stable Oxygen Calibration Data. Sites: Bartolome Island: 0 deg, 17 min S, 90 deg 33 min W. Champion Island: 1 deg, 15 min S, 90 deg, 05 min W. Urvina...

  11. Stable propagation of 'selfish'genetic elements

    Indian Academy of Sciences (India)

    Unknown

    viruses such as the Epstein-Barr virus (Harris et al 1985;. Kanda et al 2001) and bovine papilloma virus (Lehman and Botchan 1998; Ilves et al 1999), which exist pre- dominantly as extrachromosomal episomes, have been shown to utilize chromosome tethering as a means for stable segregation. The tethering mechanism ...

  12. Unconditionally stable perfectly matched layer boundary conditions

    NARCIS (Netherlands)

    De Raedt, H.; Michielsen, K.

    2007-01-01

    A brief review is given of a systematic, product-formula based approach to construct unconditionally stable algorithms for solving the time-dependent Maxwell equations. The fundamental difficulties that arise when we want to incorporate uniaxial perfectly matched layer boundary conditions into this

  13. Facies, dissolution seams and stable isotope compositions

    Indian Academy of Sciences (India)

    Stable isotope analysis of the limestone shows that 13C and 18O values are compatible with the early Mesoproterozoic open seawater composition. The ribbon limestone facies in the Rohtas Limestone is characterized by micritic beds, each decoupled in a lower band enriched and an upper band depleted in dissolution ...

  14. Connected domination stable graphs upon edge addition ...

    African Journals Online (AJOL)

    A set S of vertices in a graph G is a connected dominating set of G if S dominates G and the subgraph induced by S is connected. We study the graphs for which adding any edge does not change the connected domination number. Keywords: Connected domination, connected domination stable, edge addition ...

  15. Stable magnetic remanence in antiferromagnetic goethite.

    Science.gov (United States)

    Strangway, D W; McMahon, B E; Honea, R M

    1967-11-10

    Goethite, known to be antiferromagnetic, acquires thermoremanent magnetization at its Neel temperature of 120 degrees C. This remanence, extremely stable, is due to the presence of unbalanced spins in the antiferromagnetic structure; the spins may result from grain size, imperfections, or impurities.

  16. Diet of Tollund Man. Stable isotope analyses of an Iron Age bog body from Denmark

    DEFF Research Database (Denmark)

    Helt Nielsen, Nina; Philippsen, Bente; Jensen, L. V.

    Tollund Man is one of the world’s most famous bog bodies due to his exceptionally well-preserved head. He was found in 1950 by peat cutters in a bog near Bjældskovdal, c. 10 km west of Silkeborg. During the years, several analyses have been performed on the body to shed light on the life and death...... of Tollund Man. The investigations have primarily included forensic and medical examinations, X-rays, CT-scans and microscopical analyses of e.g. the stomach content, while chemical and isotope analyses have not been conducted. In 2016, an extraordinary grant from the municipality of Silkeborg enabled Museum...... Silkeborg to initiate a range of new scientific investigations of Tollund Man and the associated finds. These include protein analysis, multi-element analysis, Sr isotope analysis and analysis of the stable isotopes of N, C and S. This presentation focuses on measurements of the stable isotopes in bone...

  17. Growth study of nonpolar Zn{sub 1-x}Mg{sub x}O epitaxial films on a-plane bulk ZnO by plasma-assisted molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Laumer, Bernhard [Walter Schottky Institut and Physics Department, Technische Universitaet Muenchen, Am Coulombwall 4, 85748 Garching (Germany); I. Physikalisches Institut, Justus-Liebig-Universitaet Giessen, Heinrich-Buff-Ring 16, 35392 Giessen (Germany); Schuster, Fabian; Stutzmann, Martin [Walter Schottky Institut and Physics Department, Technische Universitaet Muenchen, Am Coulombwall 4, 85748 Garching (Germany); Bergmaier, Andreas; Dollinger, Guenther [Universitaet der Bundeswehr Muenchen, Fakultaet fuer Luft- und Raumfahrttechnik, Werner-Heisenberg-Weg 39, 85577 Neubiberg (Germany); Vogel, Stephen; Gries, Katharina I.; Volz, Kerstin [Philipps-Universitaet, Material Sciences Center-Structure and Technology Research Laboratory and Faculty of Physics, Hans-Meerwein-Strasse, 35032 Marburg (Germany); Eickhoff, Martin [I. Physikalisches Institut, Justus-Liebig-Universitaet Giessen, Heinrich-Buff-Ring 16, 35392 Giessen (Germany)

    2012-09-17

    Nonpolar Zn{sub 1-x}Mg{sub x}O epitaxial films were grown by plasma-assisted molecular beam epitaxy on a-plane ZnO substrates. A smooth surface morphology was accomplished under oxygen-rich growth conditions. The benefits of the use of ZnO substrates on the structural properties are reflected by a low-density of threading dislocations. Furthermore, no indications for the generation of basal plane stacking faults are found. The pseudomorphic growth on a-plane ZnO substrates efficiently locks the epitaxial Zn{sub 1-x}Mg{sub x}O films to the wurtzite structure up to x = 0.25. The Mg concentration is not constant and increases with larger thickness. The optical properties reflect the influence of alloy disorder.

  18. Development of a Safety Management Web Tool for Horse Stables.

    Science.gov (United States)

    Leppälä, Jarkko; Kolstrup, Christina Lunner; Pinzke, Stefan; Rautiainen, Risto; Saastamoinen, Markku; Särkijärvi, Susanna

    2015-11-12

    Managing a horse stable involves risks, which can have serious consequences for the stable, employees, clients, visitors and horses. Existing industrial or farm production risk management tools are not directly applicable to horse stables and they need to be adapted for use by managers of different types of stables. As a part of the InnoEquine project, an innovative web tool, InnoHorse, was developed to support horse stable managers in business, safety, pasture and manure management. A literature review, empirical horse stable case studies, expert panel workshops and stakeholder interviews were carried out to support the design. The InnoHorse web tool includes a safety section containing a horse stable safety map, stable safety checklists, and examples of good practices in stable safety, horse handling and rescue planning. This new horse stable safety management tool can also help in organizing work processes in horse stables in general.

  19. Single solid phase extraction method for the simultaneous analysis of polar and non-polar pesticides in urine samples by gas chromatography and ultra high pressure liquid chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Cazorla-Reyes, Rocío; Fernández-Moreno, José Luis; Romero-González, Roberto; Frenich, Antonia Garrido; Vidal, José Luis Martínez

    2011-07-15

    A new multiresidue method has been developed and validated for the simultaneous extraction of more than two hundred pesticides, including non-polar and polar pesticides (carbamates, organochlorine, organophosphorous, pyrethroids, herbicides and insecticides) in urine at trace levels by gas and ultra high pressure liquid chromatography coupled to ion trap and triple quadrupole mass spectrometry, respectively (GC-IT-MS/MS, UHPLC-QqQ-MS/MS). Non-polar and polar pesticides were simultaneously extracted from urine samples by a simple and fast solid phase extraction (SPE) procedure using C(18) cartridges as sorbent, and dichloromethane as elution solvent. Recovery was in the range of 60-120%. Precision values expressed as relative standard deviation (RSD) were lower than 25%. Identification and confirmation of the compounds were performed by the use of retention time windows, comparison of spectra (GC-amenable compounds) or the estimation of the ion ratio (LC-amenable compounds). For GC-amenable pesticides, limits of detection (LODs) ranged from 0.001 to 0.436 μg L(-1) and limits of quantification (LOQs) from 0.003 to 1.452 μg L(-1). For LC-amenable pesticides, LODs ranged from 0.003 to 1.048 μg L(-1) and LOQs ranged from 0.011 to 3.494 μg L(-1). Finally, the optimized method was applied to the analysis of fourteen real samples of infants from agricultural population. Some pesticides such as methoxyfenozide, tebufenozide, piperonyl butoxide and propoxur were found at concentrations ranged from 1.61 to 24.4 μg L(-1), whereas methiocarb sulfoxide was detected at trace levels in two samples. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. A combined interfacial and in-situ polymerization strategy to construct well-defined core-shell epoxy-containing SiO2-based microcapsules with high encapsulation loading, super thermal stability and nonpolar solvent tolerance

    Directory of Open Access Journals (Sweden)

    Yin Jia

    2016-10-01

    Full Text Available SiO2-based microcapsules containing hydrophobic molecules exhibited potential applications such as extrinsic self-healing, drug delivery, due to outstanding thermal and chemical stability of SiO2. However, to construct SiO2-based microcapsules with both high encapsulation loading and long-term structural stability is still a troublesome issue, limiting their further utilization. We herein design a single-batch route, a combined interfacial and in-situ polymerization strategy, to fabricate epoxy-containing SiO2-based microcapsules with both high encapsulation loading and long-term structural stability. The final SiO2-based microcapsules preserve high encapsulation loading of 85.7 wt% by controlling exclusively hydrolysis and condensed polymerization at oil/water interface in the initial interfacial polymerization step. In the subsequent in-situ polymerization step, the initial SiO2-based microcapsules as seeds could efficiently harvest SiO2 precursors and primary SiO2 particles to finely tune the SiO2 wall thickness, thereby enhancing long-term structural stability of the final SiO2-based microcapsules including high thermal stability with almost no any weight loss until 250°C, and strong tolerance against nonpolar solvents such as CCl4 with almost unchanged core-shell structure and unchanged core weight after immersing into strong solvents for up to 5 days. These SiO2-based microcapsules are extremely suited for processing them into anticorrosive coating in the presence of nonpolar solvents for self-healing application.

  1. Mutagenicity of cyclopenta-fused polynuclear aromatic hydrocarbons and a non-polar fraction from a fuel combustion sample in a Salmonella forward mutation assay without exogenous metabolic activation.

    Science.gov (United States)

    Busby, W F; Smith, H; Plummer, E F; Lafleur, A L; Mulder, P P; Boere, B B; Cornelisse, J; Lugtenburg, J

    1997-07-14

    A series of cyclopenta-fused polynuclear aromatic hydrocarbons (PAH) were tested for mutagenicity in a bacterial forward mutation assay based on resistance to 8-azaguanine (8-AG) in Salmonella typhimurium TM677 in the absence of Aroclor-induced rat liver postmitochondrial supernatant (PMS). All of the aceanthrylenes tested were mutagenic in the absence of PMS, whereas none of the acephenanthrylenes were active. The following mutagenic potency series expressed as the minimum detectable mutagen concentration (MDMC) in nmol/ml was obtained: aceanthrylene (AA) (5.5); cyclopent[h,i]aceanthrylene (CPAA)(18.2); 6-methylaceanthrylene (6-MeAA)(112); 1,2,6,7-tetrahydrocyclopent[h,i]aceanthrylene (THCPAA) (166); 1,2-dihydroaceanthrylene (DHAA) (298). Saturation of the cyclopenta rings or methylation at the 6-position of AA reduced, but did not eliminate, mutagenicity measured in the absence of PMS. AA was unusual because it was approximately 4-fold more mutagenic in the absence of PMS than in its presence. The other aceanthrylenes tested were 1.3-10.7 times more mutagenic in the presence of PMS than in its absence to give an MDMC potency series of: CPAA (3.8); 6-MeAA (10.5); AA (19.9); THCPAA (52.9); DHAA (229). Approximately 20% of the PMS-independent mutagenicity in a combustion sample from ethylene burned under fuel-rich conditions was found in a fraction containing only non-polar, 4-7 ring PAHs, widely attributed to be mutagenic only in the presence of PMS. None of this mutagenicity could be attributed to aceanthrylenes, thus other non-polar PAHs appear to possess significant PMS-independent mutagenicity as well.

  2. Chlamydia trachomatis recombinant MOMP encapsulated in PLGA nanoparticles triggers primarily T helper 1 cellular and antibody immune responses in mice: a desirable candidate nanovaccine

    Directory of Open Access Journals (Sweden)

    Fairley SJ

    2013-05-01

    Full Text Available Stacie J Fairley, Shree R Singh, Abebayehu N Yilma, Alain B Waffo, Praseetha Subbarayan, Saurabh Dixit, Murtada A Taha, Chino D Cambridge, Vida A Dennis Center for NanoBiotechnology Research, Alabama State University, Montgomery, AL, USA Abstract: We recently demonstrated by in vitro experiments that PLGA (poly D, L-lactide-co-glycolide potentiates T helper 1 (Th1 immune responses induced by a peptide derived from the recombinant major outer membrane protein (rMOMP of Chlamydia trachomatis, and may be a promising vaccine delivery system. Herein we evaluated the immune-potentiating potential of PLGA by encapsulating the full-length rMOMP (PLGA-rMOMP, characterizing it in vitro, and investigating its immunogenicity in vivo. Our hypothesis was that PLGA-rMOMP triggers Th1 immune responses in mice, which are desirable prerequisites for a C. trachomatis candidate nanovaccine. Physical-structural characterizations of PLGA-rMOMP revealed its size (approximately 272 nm, zeta potential (−14.30 mV, apparent spherical smooth morphology, and continuous slow release pattern. PLGA potentiated the ability of encapsulated rMOMP to trigger production of cytokines and chemokines by mouse J774 macrophages. Flow cytometric analyses revealed that spleen cells from BALB/c mice immunized with PLGA-rMOMP had elevated numbers of CD4+ and CD8+ T cell subsets, and secreted more rMOMP-specific interferon-gamma (Th1 and interleukin (IL-12p40 (Th1/Th17 than IL-4 and IL-10 (Th2 cytokines. PLGA-rMOMP-immunized mice produced higher serum immunoglobulin (IgG and IgG2a (Th1 than IgG1 (Th2 rMOMP-specific antibodies. Notably, sera from PLGA-rMOMP-immunized mice had a 64-fold higher Th1 than Th2 antibody titer, whereas mice immunized with rMOMP in Freund's adjuvant had only a four-fold higher Th1 than Th2 antibody titer, suggesting primarily induction of a Th1 antibody response in PLGA-rMOMP-immunized mice. Our data underscore PLGA as an effective delivery system for a C

  3. Occurrence of primarily noninducible atrioventricular nodal reentry tachycardia after radiofrequency delivery in the slow pathway region during empirical slow pathway modulation.

    Science.gov (United States)

    Wegner, Felix Konrad; Bögeholz, Nils; Leitz, Patrick; Frommeyer, Gerrit; Dechering, Dirk Georg; Kochhäuser, Simon; Lange, Philipp Sebastian; Köbe, Julia; Wasmer, Kristina; Mönnig, Gerold; Eckardt, Lars; Pott, Christian

    2017-11-01

    The first-line therapy for atrioventricular nodal reentry tachycardia (AVNRT) is catheter-based slow pathway modulation. If AVNRT is not inducible during an electrophysiological study, an empirical slow pathway modulation (ESPM) may be considered in patients with dual atrioventricular nodal physiology and/or a typical electrocardiogram (ECG). We screened 149 symptomatic patients who underwent ESPM in our department between 1993 and 2013. All patients fulfilled the following criteria: (1) either dual atrioventricular nodal (AVN) physiology with up to 2 AVN echo beats or characteristic ECG documentation or both, (2) noninducibility of AVNRT by programmed stimulation, and (3) completion of a telephone questionnaire for long-term follow-up. Out of this population we retrospectively investigated 13 patients who were primarily noninducible but in whom an AVNRT occurred during or after radiofrequency (RF) delivery. When AVNRT occurred, the procedure lost its empirical character, and RF delivery was continued until the procedural endpoint of noninducibility of AVNRT. This endpoint was reached in all but one patient (92%). After a follow-up of 73 ± 15 months, this patient was the only one who reported no benefit from the procedure. Out of 149 initially noninducible patients, a considerable number (9%) exhibited AVNRT during or after RF delivery. These patients crossed over from empirical to controlled slow pathway modulation resulting in a good clinical outcome. Our observations should encourage electrophysiologists to repeat programmed stimulation even after initial empirical RF delivery to retest for inducibility. © 2017 Wiley Periodicals, Inc.

  4. Bacterial diversity shift determined by different diets in the gut of the spotted wing fly Drosophila suzukii is primarily reflected on acetic acid bacteria

    KAUST Repository

    Vacchini, Violetta

    2016-11-25

    The pivotal role of diet in shaping gut microbiota has been evaluated in different animal models, including insects. Drosophila flies harbour an inconstant microbiota among which acetic acid bacteria (AAB) are important components. Here, we investigated the bacterial and AAB components of the invasive pest Drosophila suzukii microbiota, by studying the same insect population separately grown on fruit-based or non-fruit artificial diet. AAB were highly prevalent in the gut under both diets (90 and 92% infection rates with fruits and artificial diet, respectively). Fluorescent in situ hybridization and recolonization experiments with green fluorescent protein (Gfp)-labelled strains showed AAB capability to massively colonize insect gut. High-throughput sequencing on 16S rRNA gene indicated that the bacterial microbiota of guts fed with the two diets clustered separately. By excluding AAB-related OTUs from the analysis, insect bacterial communities did not cluster separately according to the diet, suggesting that diet-based diversification of the community is primarily reflected on the AAB component of the community. Diet influenced also AAB alpha-diversity, with separate OTU distributions based on diets. High prevalence, localization and massive recolonization, together with AAB clustering behaviour in relation to diet, suggest an AAB role in the D. suzukii gut response to diet modification. This article is protected by copyright. All rights reserved.

  5. Is Walking Capacity in Subjects with Multiple Sclerosis Primarily Related to Muscle Oxidative Capacity or Maximal Muscle Strength? A Pilot Study

    Directory of Open Access Journals (Sweden)

    Dominique Hansen

    2014-01-01

    Full Text Available Background and Purpose. Walking capacity is reduced in subjects with multiple sclerosis (MS. To develop effective exercise interventions to enhance walking capacity, it is important to determine the impact of factors, modifiable by exercise intervention (maximal muscle strength versus muscle oxidative capacity, on walking capacity. The purpose of this pilot study is to discriminate between the impact of maximal muscle strength versus muscle oxidative capacity on walking capacity in subjects with MS. Methods. From 24 patients with MS, muscle oxidative capacity was determined by calculation of exercise-onset oxygen uptake kinetics (mean response time during submaximal exercise bouts. Maximal muscle strength (isometric knee extension and flexion peak torque was assessed on dynamometer. All subjects completed a 6-minute walking test. Relationships between walking capacity (as a percentage of normal value and muscle strength (of knee flexors and extensors versus muscle oxidative capacity were assessed in multivariate regression analyses. Results. The expanded disability status score (EDSS showed a significant univariate correlation (r=-0.70, P<0.004 with walking capacity. In multivariate regression analyses, EDSS and mean response time, but not muscle strength, were independently related to walking capacity (P<0.05. Conclusions. Walking distance is, next to disability level and not taking neurologic symptoms/deficits into account, primarily related to muscle oxidative capacity in subjects with MS. Additional study is needed to further examine/verify these findings.

  6. High mobility group protein number17 cross-links primarily to histone H2A in the reconstituted HMG 17 - nucleosome core particle complex

    International Nuclear Information System (INIS)

    Cook, G.R.; Yau, P.; Yasuda, H.; Traut, R.R.; Bradbury, E.M.

    1986-01-01

    The neighbor relationship of lamb thymus High Mobility Group (HMG) protein 17 to native HeLa nucleosome core particle histones in the reconstituted complex has been studied. 125 I-labeled HMG 17 was cross-linking to core histones using the protein-protein cross-linking reagent 2-iminothiolane. Specific cross-linked products were separated on a two-dimensional Triton-acid-urea/SDS gel system, located by autoradiography, excised and quantified. Disulfide bonds in the cross links were then cleaved and the protein constituents were identified by SDS gel electrophoresis. HMG 17 cross-linked primarily to histone H2A while lower levels of cross-linking occurred between HMG 17 and the other histones. In contrast, cross-linking between two HMG 17 molecules bound on the same nucleosome was relatively rare. It is concluded that the same nucleosome was relatively rare. It is concluded that H2A comprises part of the HMG 17 binding site but that HMG 17 is sufficiently elongated and mobile to permit cross-linking to the other histones and to a second HMG 17 molecule. These results are in agreement with the current model for the structure of the nucleosome and the proposed binding sites for HMG 17

  7. On The Roman Domination Stable Graphs

    Directory of Open Access Journals (Sweden)

    Hajian Majid

    2017-11-01

    Full Text Available A Roman dominating function (or just RDF on a graph G = (V,E is a function f : V → {0, 1, 2} satisfying the condition that every vertex u for which f(u = 0 is adjacent to at least one vertex v for which f(v = 2. The weight of an RDF f is the value f(V (G = Pu2V (G f(u. The Roman domination number of a graph G, denoted by R(G, is the minimum weight of a Roman dominating function on G. A graph G is Roman domination stable if the Roman domination number of G remains unchanged under removal of any vertex. In this paper we present upper bounds for the Roman domination number in the class of Roman domination stable graphs, improving bounds posed in [V. Samodivkin, Roman domination in graphs: the class RUV R, Discrete Math. Algorithms Appl. 8 (2016 1650049].

  8. Design of optically stable image reflector system.

    Science.gov (United States)

    Tsai, Chung-Yu

    2013-08-01

    The design of a partially optically stable (POS) reflector system, in which the exit ray direction and image pose are unchanged as the reflector system rotates about a specific directional vector, was presented in an earlier study by the current group [Appl. Phys. B100, 883-890 (2010)]. The present study further proposes an optically stable image (OSI) reflector system, in which not only is the optical stability property of the POS system retained, but the image position and total ray path length are also fixed. An analytical method is proposed for the design of OSI reflector systems comprising multiple reflectors. The validity of the proposed approach is demonstrated by means of two illustrative examples.

  9. Stable microfluidic flow focusing using hydrostatics.

    Science.gov (United States)

    Gnyawali, Vaskar; Saremi, Mohammadali; Kolios, Michael C; Tsai, Scott S H

    2017-05-01

    We present a simple technique to generate stable hydrodynamically focused flows by driving the flow with hydrostatic pressure from liquid columns connected to the inlets of a microfluidic device. Importantly, we compare the focused flows generated by hydrostatic pressure and classical syringe pump driven flows and find that the stability of the hydrostatic pressure driven technique is significantly better than the stability achieved via syringe pumps, providing fluctuation-free focused flows that are suitable for sensitive microfluidic flow cytometry applications. We show that the degree of flow focusing with the hydrostatic method can be accurately controlled by the simple tuning of the liquid column heights. We anticipate that this approach to stable flow focusing will find many applications in microfluidic cytometry technologies.

  10. Utilization of stable isotopes in medicine

    International Nuclear Information System (INIS)

    1980-11-01

    The ten lectures given at this round table are presented together with a discussion. Five lectures, relating to studies in which deuterium oxide was employed as a tracer of body water, dealt with pulmonary water measurements in man and animals, the total water pool in adipose subjects, and liquid compartments in children undergoing hemodyalisis. The heavy water is analysed by infrared spectrometry and a new double spectrodoser is described. Two studies using 13 C as tracer, described the diagnosis of liver troubles and diabetes respectively. A general review of the perspectives of the application of stable isotopes in clinical medicine is followed by a comparison of the use of stable and radioactive isotopes in France [fr

  11. Thermally Stable, Latent Olefin Metathesis Catalysts

    OpenAIRE

    Thomas, Renee M.; Fedorov, Alexey; Keitz, Benjamin K.; Grubbs, Robert H.

    2011-01-01

    Highly thermally stable N-aryl,N-alkyl N-heterocyclic carbene (NHC) ruthenium catalysts were designed and synthesized for latent olefin metathesis. These catalysts showed excellent latent behavior toward metathesis reactions, whereby the complexes were inactive at ambient temperature and initiated at elevated temperatures, a challenging property to achieve with second generation catalysts. A sterically hindered N-tert-butyl substituent on the NHC ligand of the ruthenium complex was found to i...

  12. The nature of stable insomnia phenotypes.

    Science.gov (United States)

    Pillai, Vivek; Roth, Thomas; Drake, Christopher L

    2015-01-01

    We examined the 1-y stability of four insomnia symptom profiles: sleep onset insomnia; sleep maintenance insomnia; combined onset and maintenance insomnia; and neither criterion (i.e., insomnia cases that do not meet quantitative thresholds for onset or maintenance problems). Insomnia cases that exhibited the same symptom profile over a 1-y period were considered to be phenotypes, and were compared in terms of clinical and demographic characteristics. Longitudinal. Urban, community-based. Nine hundred fifty-four adults with Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition based current insomnia (46.6 ± 12.6 y; 69.4% female). None. At baseline, participants were divided into four symptom profile groups based on quantitative criteria. Follow-up assessment 1 y later revealed that approximately 60% of participants retained the same symptom profile, and were hence judged to be phenotypes. Stability varied significantly by phenotype, such that sleep onset insomnia (SOI) was the least stable (42%), whereas combined insomnia (CI) was the most stable (69%). Baseline symptom groups (cross-sectionally defined) differed significantly across various clinical indices, including daytime impairment, depression, and anxiety. Importantly, however, a comparison of stable phenotypes (longitudinally defined) did not reveal any differences in impairment or comorbid psychopathology. Another interesting finding was that whereas all other insomnia phenotypes showed evidence of an elevated wake drive both at night and during the day, the 'neither criterion' phenotype did not; this latter phenotype exhibited significantly higher daytime sleepiness despite subthreshold onset and maintenance difficulties. By adopting a stringent, stability-based definition, this study offers timely and important data on the longitudinal trajectory of specific insomnia phenotypes. With the exception of daytime sleepiness, few clinical differences are apparent across stable phenotypes.

  13. A belief-based evolutionarily stable strategy

    OpenAIRE

    Deng, Xinyang; Wang, Zhen; Liu, Qi; Deng, Yong; Mahadevan, Sankaran

    2014-01-01

    As an equilibrium refinement of the Nash equilibrium, evolutionarily stable strategy (ESS) is a key concept in evolutionary game theory and has attracted growing interest. An ESS can be either a pure strategy or a mixed strategy. Even though the randomness is allowed in mixed strategy, the selection probability of pure strategy in a mixed strategy may fluctuate due to the impact of many factors. The fluctuation can lead to more uncertainty. In this paper, such uncertainty involved in mixed st...

  14. Stable iodine prophylaxis. Recommendations of the 2nd UK Working Group on Stable Iodine Prophylaxis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The Working Group reviewed the revised Who guidance and the information published since 1991 on the risks of thyroid cancer in children from radioiodine and the risks of side effects from stable iodine. In particular, it reviewed data compiled on the incidence of thyroid cancers in children following the accident at the Chernobyl nuclear power plant in 1986. It considered whether the NRPB Earls were still appropriate, in the light of the new data. It also reviewed a range of other recommendations given by the 1st Working Group, concerning the chemical form of stable iodine tablets and practical issues concerning implementation of stable iodine prophylaxis. Finally, it reviewed the Patient Information Leaflet that is required, by law, to be included in each box of tablets and provided suggestions for information to be included in a separate information leaflet to be handed out to the public when stable iodine tablets are distributed.

  15. Detonation of Meta-stable Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, Allen; Kuhl, Allen L.; Fried, Laurence E.; Howard, W. Michael; Seizew, Michael R.; Bell, John B.; Beckner, Vincent; Grcar, Joseph F.

    2008-05-31

    We consider the energy accumulation in meta-stable clusters. This energy can be much larger than the typical chemical bond energy (~;;1 ev/atom). For example, polymeric nitrogen can accumulate 4 ev/atom in the N8 (fcc) structure, while helium can accumulate 9 ev/atom in the excited triplet state He2* . They release their energy by cluster fission: N8 -> 4N2 and He2* -> 2He. We study the locus of states in thermodynamic state space for the detonation of such meta-stable clusters. In particular, the equilibrium isentrope, starting at the Chapman-Jouguet state, and expanding down to 1 atmosphere was calculated with the Cheetah code. Large detonation pressures (3 and 16 Mbar), temperatures (12 and 34 kilo-K) and velocities (20 and 43 km/s) are a consequence of the large heats of detonation (6.6 and 50 kilo-cal/g) for nitrogen and helium clusters respectively. If such meta-stable clusters could be synthesized, they offer the potential for large increases in the energy density of materials.

  16. Two stable steady states in the Hodgkin-Huxley axons

    OpenAIRE

    Aihara, K.; Matsumoto, G.

    1983-01-01

    Two stable steady states were found in the numerical solution of the Hodgkin-Huxley equations for the intact squid axon bathed in potassium-rich sea water with an externally applied inward current. Under the conditions the two stable steady-states exist, the Hodgkin-Huxley equations have a complex bifurcation structure including, in addition to the two stable steady-states, a stable limit cycle, two unstable equilibrium points, and one asymptotically stable equilibrium point. It was also conc...

  17. Stable isotopes confirm a coastal diet for critically endangered Mediterranean monk seals.

    Science.gov (United States)

    Karamanlidis, Alexandros A; Curtis, P Jeff; Hirons, Amy C; Psaradellis, Marianna; Dendrinos, Panagiotis; Hopkins, John B

    2014-01-01

    Understanding the ecology and behaviour of endangered species is essential for developing effective management and conservation strategies. We used stable isotope analysis to investigate the foraging behaviour of critically endangered Mediterranean monk seals (Monachus monachus) in Greece. We measured carbon and nitrogen isotope ratios (expressed as δ(13)C and δ(15)N values, respectively) derived from the hair of deceased adult and juvenile seals and the muscle of their known prey to quantify their diets. We tested the hypothesis that monk seals primarily foraged for prey that occupy coastal habitats in Greece. We compared isotope values from seal hair to their coastal and pelagic prey (after correcting all prey for isotopic discrimination) and used these isotopic data and a stable isotope mixing model to estimate the proportion of coastal and pelagic resources consumed by seals. As predicted, we found that seals had similar δ(13)C values as many coastal prey species and higher δ(13)C values than pelagic species; these results, in conjunction with mean dietary estimates (coastal=61 % vs. pelagic=39 %), suggest that seals have a diverse diet comprising prey from multiple trophic levels that primarily occupy the coast. Marine resource managers should consider using the results from this study to inform the future management of coastal habitats in Greece to protect Mediterranean monk seals.

  18. Prostaglandin (PG) E3 synthesis elicted by adrenergic stimuli in guinea-pig trachea (GPT) is mediated primarily by B2 adrenergic receptors

    Energy Technology Data Exchange (ETDEWEB)

    Nadel, G.L.; Malik, K.U.; Lew, D.B. (Univ. of Tennessee, Memphis (United States))

    1990-02-26

    The purpose of this study was to examine arachidonic acid (AA) metabolism and to characterize the type of adrenergic receptor (AR) involved in the production of the major metabolite of this fatty acid. ({sup 14}C)AA was incubated with GPT-rings and the radiolabelled products were extracted and separated by TLC method. The medium was also assayed for radiolabelled immunoreactive PG's (iPG's) and leukotrienes (LT) B4 and C4 by RIA or Enzyme immunoassay (EIA) after exposure to various AR agonists. ({sup 14}C)AA was incorporated into GPT-rings and metabolized mainly into iPGE2 and smaller amounts into PGF2{alpha}. Trace amounts of PGD2 and 6-keto-PGF1{alpha} but not LTB4 or LTC4 were detected by RIA and/or EIA. Incubation of GPT rings for 15 minutes with isoproterenol and salbutamol resulted in a significant increase of PGE2 synthesis (optimum conc: 10{sup {minus}7}, 10{sup {minus}7}M respectively). In contrast, dobutamine, norepinephrine, phenylnephrine and xylazine (up to 10{sup {minus}6}M) did not significantly increase PGE2 production. Isoproterenol-induced iPGE2 production was inhibited by a selective {beta}2 antagonist, butoxamine (70%: 10{sup {minus}7}M, 91%: 10{sup {minus}6}M) and somewhat reduced by {beta}1 antagonists practolol and metoprolol (30-64%:10{sup {minus}6}M). These data suggest that isoproterenol induced iPGE2 synthesis is primarily mediated via activation of {beta}2 adrenergic receptor.

  19. Circulating platelet-activating factor is primarily cleared by transport, not intravascular hydrolysis by lipoprotein-associated phospholipase A2/ PAF acetylhydrolase.

    Science.gov (United States)

    Liu, Jinbo; Chen, Rui; Marathe, Gopal K; Febbraio, Maria; Zou, Weilin; McIntyre, Thomas M

    2011-02-18

    The phospholipid platelet-activating factor (PAF) stimulates all cells of the innate immune system and numerous cardiovascular cells. A single enzyme (plasma PAF acetylhydrolase [PAF-AH] or lipoprotein-associated phospholipase [Lp-PL]A(2)) in plasma hydrolyzes PAF, but significant controversy exists whether its action is pro- or antiinflammatory and accordingly whether its inhibition will slow cardiovascular disease. We sought to define how PAF and related short-chain oxidized phospholipids turnover in vivo and the role of PAF acetylhydrolase/Lp-PLA(2) in this process. [(3)H-acetyl]PAF was hydrolyzed by murine or human plasma (t(1/2), 3 and 7 minutes, respectively), but injected [(3)H-acetyl]PAF disappeared from murine circulation more quickly (t(1/2), PAF clearance was unchanged in PAF receptor(-/-) animals, or over the first 2 half-lives in PAF-AH(-/-) animals. [(3)H]PAF turnover was reduced by coinjecting excess unlabeled PAF or an oxidatively truncated phospholipid, and [(3)H]PAF clearance was slowed in hyperlipidemic apolipoprotein (apo)E(-/-) mice with excess circulating oxidatively truncated phospholipids. [(3)H]PAF, fluorescent NBD-PAF, or fluorescent oxidatively truncated phospholipid were primarily accumulated by liver and lung, and were transported into endothelium as intact phospholipids through a common mechanism involving TMEM30a. Circulating PAF and oxidized phospholipids are continually and rapidly cleared, and hence continually and rapidly produced. Saturable PAF receptor-independent transport, rather than just intravascular hydrolysis, controls circulating inflammatory and proapoptotic oxidized phospholipid mediators. Intravascular PAF has access to intracellular compartments. Inflammatory and proapoptotic phospholipids may accumulate in the circulation as transport is overwhelmed by substrates in hyperlipidemia.

  20. Water deficit in field-grown Gossypium hirsutum primarily limits net photosynthesis by decreasing stomatal conductance, increasing photorespiration, and increasing the ratio of dark respiration to gross photosynthesis.

    Science.gov (United States)

    Chastain, Daryl R; Snider, John L; Collins, Guy D; Perry, Calvin D; Whitaker, Jared; Byrd, Seth A

    2014-11-01

    Much effort has been expended to improve irrigation efficiency and drought tolerance of agronomic crops; however, a clear understanding of the physiological mechanisms that interact to decrease source strength and drive yield loss has not been attained. To elucidate the underlying mechanisms contributing to inhibition of net carbon assimilation under drought stress, three cultivars of Gossypium hirsutum were grown in the field under contrasting irrigation regimes during the 2012 and 2013 growing season near Camilla, Georgia, USA. Physiological measurements were conducted on three sample dates during each growing season (providing a broad range of plant water status) and included, predawn and midday leaf water potential (ΨPD and ΨMD), gross and net photosynthesis, dark respiration, photorespiration, and chlorophyll a fluorescence. End-of-season lint yield was also determined. ΨPD ranged from -0.31 to -0.95MPa, and ΨMD ranged from -1.02 to -2.67MPa, depending upon irrigation regime and sample date. G. hirsutum responded to water deficit by decreasing stomatal conductance, increasing photorespiration, and increasing the ratio of dark respiration to gross photosynthesis, thereby limiting PN and decreasing lint yield (lint yield declines observed during the 2012 growing season only). Conversely, even extreme water deficit, causing a 54% decline in PN, did not negatively affect actual quantum yield, maximum quantum yield, or photosynthetic electron transport. It is concluded that PN is primarily limited in drought-stressed G. hirsutum by decreased stomatal conductance, along with increases in respiratory and photorespiratory carbon losses, not inhibition or down-regulation of electron transport through photosystem II. It is further concluded that ΨPD is a reliable indicator of drought stress and the need for irrigation in field-grown cotton. Copyright © 2014 Elsevier GmbH. All rights reserved.

  1. The members of M20D peptidase subfamily from Burkholderia cepacia, Deinococcus radiodurans and Staphylococcus aureus (HmrA) are carboxydipeptidases, primarily specific for Met-X dipeptides.

    Science.gov (United States)

    Jamdar, Sahayog N; Are, Venkata N; Navamani, Mallikarjunan; Kumar, Saurabh; Nagar, Vandan; Makde, Ravindra D

    2015-12-01

    Three members of peptidase family M20D from Burkholderia cepacia (BcepM20D; Uniprot accession no. A0A0F7GQ23), Deinococcus radiodurans R1 (DradM20D; Uniprot accession no. Q9RTP6) and Staphylococcus aureus (HmrA; Uniprot accession no. Q99Q45) were characterized in terms of their preference for various substrates. The results thus reveal that all the enzymes including HmrA lack endopeptidase as well as aminopeptidase activities and possess strong carboxypeptidase activity. Further, the amidohydrolase activity exerted on other substrates like N-Acetyl-Amino acids, N-Carbobenzoxyl-Amino acids and Indole acetic acid (IAA)-Amino acids is due to the ability of these enzymes to accommodate different types of chemical groups other than the amino acid at the S1 pocket. Further, data on peptide hydrolysis strongly suggests that all the three enzymes are primarily carboxydipeptidases exhibiting highest catalytic efficiency (kcat/Km 5-36 × 10(5) M(-1) s(-1)) for Met-X substrates, where -X could be Ala/Gly/Ser/Tyr/Phe/Leu depending on the source organism. The supportive evidence for the substrate specificities was also provided with the molecular docking studies carried out using structure of SACOL0085 and homology modelled structure of BcepM20D. The preference for different substrates, their binding at active site of the enzyme and possible role of these enzymes in recycling of methionine are discussed in this study. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. HIV/AIDS stigma among a sample of primarily African-American and Latino men who have sex with men social media users.

    Science.gov (United States)

    Garett, Renee; Smith, Justin; Chiu, Jason; Young, Sean D

    2016-01-01

    The recent increase in social media use allows these technologies to rapidly reach communities with higher HIV prevalence, such as African-American and Latino men who have sex with men (MSM). However, no studies have looked at HIV/AIDS stigma among social media users from African-American and Latino MSM communities, or the association between stigma and social media use among these groups. This study sought to assess the level of HIV/AIDS stigma among a sample of social media-using African-American and Latino MSM from Los Angeles. A total of 112 (primarily African-American and Latino, n = 98, 88%) MSM Facebook users completed a survey on demographics, online social network use, and HIV/AIDS stigma. A composite stigma score was created by taking the cumulative score from a 15-item stigma questionnaire. Cumulative logistic models were used to assess the association between HIV/AIDS stigma and online social network use. In general, participants reported a low level of HIV/AIDS stigma (mean = 22.2/75, SD = 5.74). HIV/AIDS stigma composite score was significantly associated with increased time spent on online social networks each day (Adjusted odds ratios (AOR): 1.07, 95% CI: 1.00, 1.15). Among this diverse sample of MSM online social network users, findings suggest that HIV/AIDS stigma is associated with usage of social media. We discuss the implications of this work for future HIV prevention.

  3. (-)Deprenyl and (-)1-phenyl-2-propylaminopentane, [(-)PPAP], act primarily as potent stimulants of action potential-transmitter release coupling in the catecholaminergic neurons.

    Science.gov (United States)

    Knoll, J; Miklya, I; Knoll, B; Markó, R; Kelemen, K

    1996-01-01

    The activity of the catecholaminergic neurons in the rat brain is enhanced significantly 30 min after the subcutaneous injection of very small doses of (-)deprenyl (threshold doses: 0.01 mg/kg for noradrenergic neurons and 0.025 mg/kg for dopaminergic neurons). As a catecholaminergic activity enhancer (CAE) substance (-)deprenyl is about ten times more potent than its parent compound, (-)methamphetamine. While the (+)methamphetamine is 3-5 times more potent than (-)methamphetammine in releasing catecholamines, the (-)methamphetamine is the more potent CAE substance. The mechanism of the CAE effect of (-)deprenyl and (-)PPAP, a deprenyl-derived substance devoid of MAO inhibitory potency, was studied in rats by measuring: a) the release of catecholamines from striatum, substantia nigra, tuberculum olfactorium and locus coeruleus; b) the stimulation induced release of 3H-noradrenaline from the isolated brain stem; and c) the antagonistic effect against tetrabenazine-induced depression of learning in the shuttle box. The CAE effect was found to be unrelated: a) to the inhibition of MAO activity; b) to the inhibition of presynaptic catecholamine receptors; c) to the inhibition of the uptake of catecholamines; and d) to the release of catecholamines. It was concluded that (-)deprenyl and (-)PPAP act primarily as potent stimulants of action potential-transmitter release coupling in the catecholaminergic neurons of the brain. We show that both (-)deprenyl and (-)PPAP enhance the inward Ca2+ current in sino-auricular fibers of the frog heart. (-)PPAP was much more potent than either (+)PPAP or (-)deprenyl in this test.

  4. Sitagliptin reduces cardiac apoptosis, hypertrophy and fibrosis primarily by insulin-dependent mechanisms in experimental type-II diabetes. Potential roles of GLP-1 isoforms.

    Directory of Open Access Journals (Sweden)

    Belén Picatoste

    Full Text Available BACKGROUND: Myocardial fibrosis is a key process in diabetic cardiomyopathy. However, their underlying mechanisms have not been elucidated, leading to a lack of therapy. The glucagon-like peptide-1 (GLP-1 enhancer, sitagliptin, reduces hyperglycemia but may also trigger direct effects on the heart. METHODS: Goto-Kakizaki (GK rats developed type-II diabetes and received sitagliptin, an anti-hyperglycemic drug (metformin or vehicle (n=10, each. After cardiac structure and function assessment, plasma and left ventricles were isolated for biochemical studies. Cultured cardiomyocytes and fibroblasts were used for in vitro assays. RESULTS: Untreated GK rats exhibited hyperglycemia, hyperlipidemia, plasma GLP-1 decrease, and cardiac cell-death, hypertrophy, fibrosis and prolonged deceleration time. Moreover, cardiac pro-apoptotic/necrotic, hypertrophic and fibrotic factors were up-regulated. Importantly, both sitagliptin and metformin lessened all these parameters. In cultured cardiomyocytes and cardiac fibroblasts, high-concentration of palmitate or glucose induced cell-death, hypertrophy and fibrosis. Interestingly, GLP-1 and its insulinotropic-inactive metabolite, GLP-1(9-36, alleviated these responses. In addition, despite a specific GLP-1 receptor was only detected in cardiomyocytes, GLP-1 isoforms attenuated the pro-fibrotic expression in cardiomyocytes and fibroblasts. In addition, GLP-1 receptor signalling may be linked to PPARδ activation, and metformin may also exhibit anti-apoptotic/necrotic and anti-fibrotic direct effects in cardiac cells. CONCLUSIONS: Sitagliptin, via GLP-1 stabilization, promoted cardioprotection in type-II diabetic hearts primarily by limiting hyperglycemia e hyperlipidemia. However, GLP-1 and GLP-1(9-36 promoted survival and anti-hypertrophic/fibrotic effects on cultured cardiac cells, suggesting cell-autonomous cardioprotective actions.

  5. Neurotoxicity in Sri Lankan Russell's Viper (Daboia russelii) Envenoming is Primarily due to U1-viperitoxin-Dr1a, a Pre-Synaptic Neurotoxin.

    Science.gov (United States)

    Silva, Anjana; Kuruppu, Sanjaya; Othman, Iekhsan; Goode, Robert J A; Hodgson, Wayne C; Isbister, Geoffrey K

    2017-01-01

    Russell's vipers are snakes of major medical importance in Asia. Russell's viper (Daboia russelii) envenoming in Sri Lanka and South India leads to a unique, mild neuromuscular paralysis, not seen in other parts of the world where the snake is found. This study aimed to identify and pharmacologically characterise the major neurotoxic components of Sri Lankan Russell's viper venom. Venom was fractionated using size exclusion chromatography and reverse-phase high-performance liquid chromatography (RP-HPLC). In vitro neurotoxicities of the venoms, fractions and isolated toxins were measured using chick biventer and rat hemidiaphragm preparations. A phospholipase A 2 (PLA 2 ) toxin, U1-viperitoxin-Dr1a (13.6 kDa), which constitutes 19.2 % of the crude venom, was isolated and purified using HPLC. U1-viperitoxin-Dr1a produced concentration-dependent in vitro neurotoxicity abolishing indirect twitches in the chick biventer nerve-muscle preparation, with a t 90 of 55 ± 7 min only at 1 μM. The toxin did not abolish responses to acetylcholine and carbachol indicating pre-synaptic neurotoxicity. Venom, in the absence of U1-viperitoxin-Dr1a, did not induce in vitro neurotoxicity. Indian polyvalent antivenom, at the recommended concentration, only partially prevented the neurotoxic effects of U1-viperitoxin-Dr1a. Liquid chromatography mass spectrometry analysis confirmed that U1-viperitoxin-Dr1a was the basic S-type PLA 2 toxin previously identified from this venom (NCBI-GI: 298351762; SwissProt: P86368). The present study demonstrates that neurotoxicity following Sri Lankan Russell's viper envenoming is primarily due to the pre-synaptic neurotoxin U1-viperitoxin-Dr1a. Mild neurotoxicity observed in severely envenomed Sri Lankan Russell's viper bites is most likely due to the low potency of U1-viperitoxin-Dr1a, despite its high relative abundance in the venom.

  6. Peanut allergy is common among hazelnut-sensitized subjects but is not primarily the result of IgE cross-reactivity.

    Science.gov (United States)

    Masthoff, L J; van Hoffen, E; Mattsson, L; Lidholm, J; Andersson, K; Zuidmeer-Jongejan, L; Versteeg, S A; Bruijnzeel-Koomen, C A; Knulst, A C; Pasmans, S G; van Ree, R

    2015-03-01

    Hazelnut and peanut are botanically unrelated foods, but patients are often sensitized and allergic to both, for reasons that are not well understood. To investigate molecular cosensitization and cross-reactivity to peanut in hazelnut-sensitized individuals, children (n = 81) and adults (n = 80) were retrospectively selected based on sensitization to hazelnut. IgE to hazelnut extract, Cor a 1, 8, 9 and 14, to peanut extract, Ara h 1, 2, 3, 8 and 9, and to Bet v 1 was determined by ImmunoCAP. Allergy to hazelnut and peanut was established by DBPCFC and/or detailed clinical history. Patients were either tolerant or displayed subjective or objective symptoms to either food. IgE cross-reactivity between hazelnut and peanut storage proteins was assessed by reciprocal ImmunoCAP inhibition experiments. Of the 161 hazelnut-sensitized subjects, 109 (68%) were also sensitized to peanut, and 73 (45%) had clinical expression of allergy to peanut that was not associated with the presence or severity of hazelnut allergy. Instead, it was associated with IgE reactivity to peanut storage proteins, in particular Ara h 2. No cross-reactivity could be detected between Ara h 2 and Cor a 14, and 2 of 13 subjects displayed extensive cross-reactivity between 11S globulins; in plasma of both individuals, Ara h 3 almost completely inhibited IgE binding to Cor a 9. Peanut allergy is not primarily the result of IgE cross-reactivity to hazelnut storage proteins. IgE to Cor a 14 and Ara h 2 may serve as useful markers of primary sensitization to hazelnut and peanut, respectively. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. The carbon stable isotope biogeochemistry of streams, Taylor Valley, Antarctica

    International Nuclear Information System (INIS)

    Lyons, W.B.; Leslie, D.L.; Harmon, R.S.; Neumann, K.; Welch, K.A.; Bisson, K.M.; McKnight, D.M.

    2013-01-01

    Highlights: ► δ 13 C-DIC reported from McMurdo Dry Valleys, Antarctica, streams. ► Stream water δ 13 C PDB values range −9.4‰ to +5.1‰, largely inorganic in character. ► Atmospheric exchange is the dominant control on δ 13 C-DIC. - Abstract: The McMurdo Dry Valleys region of Antarctica is the largest ice-free region on the continent. This study reports the first C stable isotope measurements for dissolved inorganic C present in ephemeral streams in four dry valleys that flow for four to twelve weeks during the austral summer. One of these valleys, Taylor Valley, has been the focus of the McMurdo Dry Valleys Long-Term Ecological Research (MCM-LTER) program since 1993. Within Taylor Valley, numerous ephemeral streams deliver water to three perennially ice-covered, closed-basin lakes: Lake Fryxell, Lake Hoare, and Lake Bonney. The Onyx River in the Wright Valley, the longest river in Antarctica, flows for 40 km from the Wright Lower Glacier and Lake Brownworth at the foot of the glacier to Lake Vanda. Streamflow in the McMurdo Dry Valley streams is produced primarily from glacial melt, as there is no overland flow. However, hyporheic zone exchange can be a major hydrogeochemical process in these streams. Depending on landscape position, these streams vary in gradient, channel substrate, biomass abundance, and hyporheic zone extent. This study sampled streams from Taylor, Wright, Garwood, and Miers Valleys and conducted diurnal sampling of two streams of different character in Taylor Valley. In addition, transect sampling was undertaken of the Onyx River in Wright Valley. The δ 13 C PDB values from these streams span a range of greater than 14‰, from −9.4‰ to +5.1‰, with the majority of samples falling between −3‰ and +2‰, suggesting that the C stable isotope composition of dissolved C in McMurdo Dry Valley streams is largely inorganic in character. Because there are no vascular plants on this landscape and no groundwater input to these

  8. Microbiological characterization of stable resuspended dust

    Directory of Open Access Journals (Sweden)

    Nora Kováts

    2016-06-01

    Full Text Available Objectives: Air quality in the stables is characterized by elevated level of dust and aeroallergens which are supposed to directly cause or exacerbate several respiratory disorders. The most often recognized problem is recurrent airway obstruction (RAO, previously known as chronic obstructive pulmonary disease (COPD. There is some indication that aeroallergens (among them endotoxins may also cause inflammation in human airways and may exceed safe levels in stables. Monitoring studies have covered mainly the determination of the concentration of respirable particles and of culturable fungi and their toxins. However, these particles do not only directly affect the respiratory system, but might act as a carrier conveying toxic contaminants and biological agents such as bacteria. In a typical, 20-horse Hungarian stable, microbial community of respirable fraction of resuspended dust has been characterized to reveal if these particles convey hazardous pathogenic bacteria, posing risk to either horses or staff. Material and Methods: Resuspended dust was sampled using a mobile instrument. The instrument contains a PARTISOL-FRM model 2000 sampler that was operated at a flow rate of 16.7 l/min and a cyclone separator which collected the particulate matter with an aerodynamic size between 1 μm and 10 μm (PM1–10 fraction. Microbial taxa were identified by culture-independent next generation sequencing (NGS of variable 16S ribosomal ribonucleic acid (rRNA gene regions. Results: In total, 1491 different taxa were identified, of them 384 were identified to species level, 961 to genus level. The sample was dominated by common ubiquitous soil and organic material-dwelling taxa. Conclusions: Pathogens occurred at low abundance, and were represented by mostly facultative human pathogens, with the prevalence of Staphylococcus species.

  9. Stable channel of reclaimed tidal lowland

    Science.gov (United States)

    Syarifudin, Achmad; Imanuddin, Momon S.; Moerwanto, Arie S.; Suryadi, F. X.

    2017-11-01

    This study aimed to develop models of the Operation and Maintenance in the reclaimed tidal marsh area to get a stable channel. The research location is reclaimed tidal delta area Telang I Primary 8 representing land typology A/B and a survey conducted in 13 South Secondary Schemes following existing tertiary Telang I. MIKE - 11 computer models used used to analyze the movement of sediment in the channel in both the Primary channel 8, SPD, SDU and tertiary channels in block 13 South. Calibration model with multiple channels in the field of physical parameters has been performed to obtain results close to the results of measurement modeling sediment movement in the channel. The integration models of MIKE - 11 models with various scenarios are used to model the operation and maintenance of the channel in the tidal marsh area to get a stable channel. According to the scheme P8 - 13S, OM models obtained 75 percent, in which the secondary channel (SPD/SDU) and built flap gate in tertiary channel, get a well prototype model of the stable channel (equilibriums), where the average erosion on P8 at a distance of 3,200 m in the amount of 4,472,049 m3 and the mean sedimentation in the SPD of 963,836 m3 and mean of sedimentation in the tertiary channel of 3,508,213 m3. Similarly, on average erosion P8 by 4,135,649 m3 and the mean sedimentation in the SDU of 681,304 m3 and the mean sedimentation in the tertiary channel of 3,454,345 m3.

  10. Magnetic resonance hypointensive signal primarily originates from extracellular iron particles in the long-term tracking of mesenchymal stem cells transplanted in the infarcted myocardium

    Directory of Open Access Journals (Sweden)

    Huang Z

    2015-03-01

    deposits were detected by pathological examination. However, iron particles were predominantly distributed in the extracellular space, and a minority was distributed within CD68-positive macrophages and other CD68-negative cells. No sex-determining region Y DNA of donor MSCs was detected.Conclusion: CMR hypointensive signal is primarily caused by extracellular iron particles in the long-term tracking of transplanted MSCs after myocardial infarction. Consideration should be given to both the false-positive signal and the potential cardiac toxicity of long-standing iron deposits in the heart. Keywords: superparamagnetic iron oxide nanoparticles, SPIO, cardiac magnetic resonance (CMR, stem cells tracking, extracellular iron particles, myocardial infarction (MI

  11. Aggressive Fibromatosis: Evidence for a Stable Phase

    Directory of Open Access Journals (Sweden)

    Gillian Mitchell

    1998-01-01

    Full Text Available Purpose. Aggressive fibromatosis (AF is an uncommon locally infiltrating benign disease of soft tissue for which treatment comprises complete surgical resection. Radiotherapy can be given postoperatively if the margin is incompletely resected. If the tumour is inoperable radiotherapy provides an alternative treatment. Hormone therapy and cytotoxic chemotherapy have also been used for unresectable or recurrent disease. All treatment modalities carry an associated morbidity. We believe that the natural history of aggressive fibromatosis may include a period of stable disease without progression, during which time, treatment is not always necessary.

  12. Stable isogeometric analysis of trimmed geometries

    Science.gov (United States)

    Marussig, Benjamin; Zechner, Jürgen; Beer, Gernot; Fries, Thomas-Peter

    2017-04-01

    We explore extended B-splines as a stable basis for isogeometric analysis with trimmed parameter spaces. The stabilization is accomplished by an appropriate substitution of B-splines that may lead to ill-conditioned system matrices. The construction for non-uniform knot vectors is presented. The properties of extended B-splines are examined in the context of interpolation, potential, and linear elasticity problems and excellent results are attained. The analysis is performed by an isogeometric boundary element formulation using collocation. It is argued that extended B-splines provide a flexible and simple stabilization scheme which ideally suits the isogeometric paradigm.

  13. Remarks on stable and quasi-stable k-strings at large N

    International Nuclear Information System (INIS)

    Armoni, A.; Shifman, M.

    2003-01-01

    We discuss k-strings in the large-N Yang-Mills theory and its supersymmetric extension. Whereas the tension of the bona fide (stable) QCD string is expected to depend only on the N-ality of the representation, tensions that depend on specific representation R are often reported in the lattice literature. In particular, adjoint strings are discussed and found in certain simulations. We clarify this issue by systematically exploiting the notion of the quasi-stable strings which becomes well-defined at large N. The quasi-stable strings with representation-dependent tensions decay, but the decay rate (per unit length per unit time) is suppressed as Λ 2 F(N) where F(N) falls off as a function of N. It can be determined on the case-by-case basis. The quasi-stable strings eventually decay into stable strings whose tension indeed depends only on the N-ality. We also briefly review large-N arguments showing why the Casimir formula for the string tension cannot be correct, and present additional arguments in favor of the sine formula. Finally, we comment on the relevance of our estimates to Euclidean lattice measurements

  14. Multivariate Max-Stable Spatial Processes

    KAUST Repository

    Genton, Marc G.

    2014-01-06

    Analysis of spatial extremes is currently based on univariate processes. Max-stable processes allow the spatial dependence of extremes to be modelled and explicitly quantified, they are therefore widely adopted in applications. For a better understanding of extreme events of real processes, such as environmental phenomena, it may be useful to study several spatial variables simultaneously. To this end, we extend some theoretical results and applications of max-stable processes to the multivariate setting to analyze extreme events of several variables observed across space. In particular, we study the maxima of independent replicates of multivariate processes, both in the Gaussian and Student-t cases. Then, we define a Poisson process construction in the multivariate setting and introduce multivariate versions of the Smith Gaussian extremevalue, the Schlather extremal-Gaussian and extremal-t, and the BrownResnick models. Inferential aspects of those models based on composite likelihoods are developed. We present results of various Monte Carlo simulations and of an application to a dataset of summer daily temperature maxima and minima in Oklahoma, U.S.A., highlighting the utility of working with multivariate models in contrast to the univariate case. Based on joint work with Simone Padoan and Huiyan Sang.

  15. Application of stable isotope to breath test

    International Nuclear Information System (INIS)

    Sasaki, Yasuto

    1988-01-01

    Needles to say, radioisotopes have good characteristics as a tracer for examining biological functions. In fact, scyntigraphy is widely used over Japan. It is true, however, that there are some difficulties in applying radioisotopes to humans. Thus, greater attention began to be attracted to stable isotopes in the late 1960s, because these substances can be used for infants and pregnant women. They can be stored for a long period of time since they do not suffer damping as in the case of radioisotopes. In addition to serving as a tracer, stable isotopes can provide structural-chemical information including the position of isotope labels, and the mass and atomic composition of fragment ions. Such techniques as NMR spectroscopy is employed for this purpose. The method is currently used to perform examinations of congenital metabolic disorders. The carbon isotopes of 13 C and 14 C are used for breath test. Compounds labeled with these isotopes are administered and their ratio to the total CO 2 in breath is measured to diagnose diseases. In the early 1970s, 13 C has come into use for breath test. Similar breath test is applied to diagnosis of the bacterial overgrowth syndrome and ileal dysfunction syndrome. (Nogami, K.)

  16. Stable states in a strong IR field

    Science.gov (United States)

    Zhong, Changchun; Robicheaux, Francis

    2015-05-01

    It is found that 10% of atoms stay in the quasi-stable states after being exposed to intense laser or microwave (MW) pulses, even though the pulses' intensity is much stronger than that needed for static fields ionization. The reason why atoms survive those strong pulses has attracted growing attentions. A. Arakelyan et al. have observed the optical spectra of the surviving Lithium atoms after interaction with intense 38-GHz MW fields for more than 1000 cycles, and the spectra exhibit a periodic train of peaks 38 GHz apart. It suggests that those weakly bound Rydberg electrons seldom go back to the ionic core, where the cycle average energy exchange happens. In this study, we are interested in the electron behavior in the presence of intense infrared fields with a much shorter wavelength (1000 nm). By solving the full 3D time dependent Schrodinger equation, we calculate the spectra of the surviving atoms under intense IR fields. Our numerical calculations show atoms survive the intense field in quasi-stable states for a long time, and the optical spectra are obviously modulated by the IR frequency. Through tuning the ponderomotive energy, we see how field parameters affect the behavior of electrons. Different atoms, such as Hydrogen, Helium, Lithium, and Sodium, are tested to see how atom's energy structures influence the results.

  17. Color stable manganese-doped phosphors

    Science.gov (United States)

    Lyons, Robert Joseph [Burnt Hills, NY; Setlur, Anant Achyut [Niskayuna, NY; Deshpande, Anirudha Rajendra [Twinsburg, OH; Grigorov, Ljudmil Slavchev [Sofia, BG

    2012-08-28

    A process for preparing color stable Mn.sup.+4 doped phosphors includes providing a phosphor of formula I; A.sub.x[MF.sub.y]:Mn.sup.+4 I and contacting the phosphor in particulate form with a saturated solution of a composition of formula II in aqueous hydrofluoric acid; A.sub.x[MF.sub.y]; II wherein A is Li, Na, K, Rb, Cs, NR.sub.4 or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; R is H, lower alkyl, or a combination thereof; x is the absolute value of the charge of the [MF.sub.y] ion; and y is 5, 6 or 7. In particular embodiments, M is Si, Ge, Sn, Ti, Zr, or a combination thereof. A lighting apparatus capable of emitting white light includes a semiconductor light source; and a phosphor composition radiationally coupled to the light source, and which includes a color stable Mn.sup.+4 doped phosphor.

  18. TNF-α decreases VEGF secretion in highly polarized RPE cells but increases it in non-polarized RPE cells related to crosstalk between JNK and NF-κB pathways.

    Directory of Open Access Journals (Sweden)

    Hiroto Terasaki

    Full Text Available Asymmetrical secretion of vascular endothelial growth factor (VEGF by retinal pigment epithelial (RPE cells in situ is critical for maintaining the homeostasis of the retina and choroid. VEGF is also involved in the development and progression of age-related macular degeneration (AMD. We studied the effect of tumor necrosis factor-α (TNF-α on the secretion of VEGF in polarized and non-polarized RPE cells (P-RPE cells and N-RPE cells, respectively in culture and in situ in rats. A subretinal injection of TNF-α caused a decrease in VEGF expression and choroidal atrophy. Porcine RPE cells were seeded on Transwell™ filters, and their maturation and polarization were confirmed by the asymmetrical VEGF secretion and trans electrical resistance. Exposure to TNF-α decreased the VEGF secretion in P-RPE cells but increased it in N-RPE cells in culture. TNF-α inactivated JNK in P-RPE cells but activated it in N-RPE cells, and TNF-α activated NF-κB in P-RPE cells but not in N-RPE cells. Inhibition of NF-κB activated JNK in both types of RPE cells indicating crosstalk between JNK and NF-κB. TNF-α induced the inhibitory effects of NF-κB on JNK in P-RPE cells because NF-κB is continuously inactivated. In N-RPE cells, however, it was not evident because NF-κB was already activated. The basic activation pattern of JNK and NF-κB and their crosstalk led to opposing responses of RPE cells to TNF-α. These results suggest that VEGF secretion under inflammatory conditions depends on cellular polarization, and the TNF-α-induced VEGF down-regulation may result in choroidal atrophy in polarized physiological RPE cells. TNF-α-induced VEGF up-regulation may cause neovascularization by non-polarized or non-physiological RPE cells.

  19. Lowering coefficient of friction in Cu alloys with stable gradient nanostructures.

    Science.gov (United States)

    Chen, Xiang; Han, Zhong; Li, Xiuyan; Lu, K

    2016-12-01

    The coefficient of friction (COF) of metals is usually high, primarily because frictional contacts induce plastic deformation underneath the wear surface, resulting in surface roughening and formation of delaminating tribolayers. Lowering the COF of metals is crucial for improving the reliability and efficiency of metal contacts in engineering applications but is technically challenging. Refining the metals' grains to nanoscale cannot reduce dry-sliding COFs, although their hardness may be elevated many times. We report that a submillimeter-thick stable gradient nanograined surface layer enables a significant reduction in the COF of a Cu alloy under high-load dry sliding, from 0.64 (coarse-grained samples) to 0.29, which is smaller than the COFs of many ceramics. The unprecedented stable low COF stems from effective suppression of sliding-induced surface roughening and formation of delaminating tribolayer, owing to the stable gradient nanostructures that can accommodate large plastic strains under repeated sliding for more than 30,000 cycles.

  20. Estimation of Time-Varying Autoregressive Symmetric Alpha Stable

    Data.gov (United States)

    National Aeronautics and Space Administration — In the last decade alpha-stable distributions have become a standard model for impulsive data. Especially the linear symmetric alpha-stable processes have found...

  1. Association between mutation spectra and stable and unstable DNA adduct profiles in Salmonella for benzo[a]pyrene and dibenzo[a,l]pyrene

    Energy Technology Data Exchange (ETDEWEB)

    DeMarini, David M., E-mail: demarini.david@epa.gov [Integrated Systems Toxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Hanley, Nancy M.; Warren, Sarah H.; Adams, Linda D.; King, Leon C. [Integrated Systems Toxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States)

    2011-09-01

    Highlights: {yields} Benzo[a]pyrene (BP) induces stable DNA adducts and mutations primarily at guanine. {yields} Dibenzo[a,l]pyrene (DBP) induces them primarily at adenine. {yields} BP induces abasic sites, but DBP does not in the Salmonella mutagenicity assay. {yields} Stable DNA adducts alone appear to account for the mutation spectrum of DBP. {yields} Stable DNA adducts and possibly abasic sites account for the mutation spectrum of BP. - Abstract: Benzo[a]pyrene (BP) and dibenzo[a,l]pyrene (DBP) are two polycyclic aromatic hydrocarbons (PAHs) that exhibit distinctly different mutagenicity and carcinogenicity profiles. Although some studies show that these PAHs produce unstable DNA adducts, conflicting data and arguments have been presented regarding the relative roles of these unstable adducts versus stable adducts, as well as oxidative damage, in the mutagenesis and tumor-mutation spectra of these PAHs. However, no study has determined the mutation spectra along with the stable and unstable DNA adducts in the same system with both PAHs. Thus, we determined the mutagenic potencies and mutation spectra of BP and DBP in strains TA98, TA100 and TA104 of Salmonella, and we also measured the levels of abasic sites (aldehydic-site assay) and characterized the stable DNA adducts ({sup 32}P-postlabeling/HPLC) induced by these PAHs in TA104. Our results for the mutation spectra and site specificity of stable adducts were consistent with those from other systems, showing that DBP was more mutagenic than BP in TA98 and TA100. The mutation spectra of DBP and BP were significantly different in TA98 and TA104, with 24% of the mutations induced by BP in TA98 being complex frameshifts, whereas DBP produced hardly any of these mutations. In TA104, BP produced primarily GC to TA transversions, whereas DBP produced primarily AT to TA transversions. The majority (96%) of stable adducts induced by BP were at guanine, whereas the majority (80%) induced by DBP were at adenine

  2. Stable CSR in Storage Rings: A Model

    International Nuclear Information System (INIS)

    Sannibale, F.

    2005-01-01

    A comprehensive historical view of the work done on coherent synchrotron radiation (CSR) in storage rings is given in reference [1]. Here we want just to point out that even if the issue of CSR in storage rings was already discussed over 50 years ago, it is only recently that a considerable number of observations have been reported. In fact, intense bursts of coherent synchrotron radiation with a stochastic character were measured in the terahertz frequency range, at several synchrotron light source storage rings [2-8]. It has been shown [8-11], that this bursting emission of CSR is associated with a single bunch instability, usually referred as microbunching instability (MBI), driven by the fields of the synchrotron radiation emitted by the bunch itself. Of remarkably different characteristics was the CSR emission observed at BESSY II in Berlin, when the storage ring was tuned into a special low momentum compaction mode [12, 13]. In fact, the emitted radiation was not the quasi-random bursting observed in the other machines, but a powerful and stable flux of broadband CSR in the terahertz range. This was an important result, because it experimentally demonstrated the concrete possibility of constructing a stable broadband source with extremely high power in the terahertz region. Since the publication of the first successful experiment using the ring as a CSR source [14], BESSY II has regular scheduled user's shifts dedicated to CSR experiments. At the present time, several other laboratories are investigating the possibility of a CSR mode of operation [15-17] and a design for a new ring optimized for CSR is at an advanced stage [18]. In what follows, we describe a model that first accounts for the BESSY II observations and then indicates that the special case of BESSY II is actually quite general and typical when relativistic electron storage rings are tuned for short bunches. The model provides a scheme for predicting and optimizing the performance of ring

  3. Stable CSR in storage rings: A model

    International Nuclear Information System (INIS)

    Sannibale, Fernando; Byrd, John M.; Loftsdottir, Agusta; Venturini, Marco; Abo-Bakr, Michael; Feikes, Jorge; Holldack, Karsten; Kuske, Peter; Wustefeld, Godehart; Hubers, Heinz-Willerm; Warnock, Robert

    2005-01-01

    A comprehensive historical view of the work done on coherent synchrotron radiation (CSR) in storage rings is given in reference [1]. Here we want just to point out that even if the issue of CSR in storage rings was already discussed over 50 years ago, it is only recently that a considerable number of observations have been reported. In fact, intense bursts of coherent synchrotron radiation with a stochastic character were measured in the terahertz frequency range, at several synchrotron light source storage rings [2-8]. It has been shown [8-11], that this bursting emission of CSR is associated with a single bunch instability, usually referred as microbunching instability (MBI), driven by the fields of the synchrotron radiation emitted by the bunch itself. Of remarkably different characteristics was the CSR emission observed at BESSY II in Berlin, when the storage ring was tuned into a special low momentum compaction mode [12, 13]. In fact, the emitted radiation was not the quasi-random bursting observed in the other machines, but a powerful and stable flux of broadband CSR in the terahertz range. This was an important result, because it experimentally demonstrated the concrete possibility of constructing a stable broadband source with extremely high power in the terahertz region. Since the publication of the first successful experiment using the ring as a CSR source [14], BESSY II has regular scheduled user s shifts dedicated to CSR experiments. At the present time, several other laboratories are investigating the possibility of a CSR mode of operation [15-17] and a design for a new ring optimized for CSR is at an advanced stage [18]. In what follows, we describe a model that first accounts for the BESSY II observations and then indicates that the special case of BESSY II is actually quite general and typical when relativistic electron storage rings are tuned for short bunches. The model provides a scheme for predicting and optimizing the performance of ring

  4. Chance and stability stable distributions and their applications

    CERN Document Server

    Uchaikin, Vladimir V

    1999-01-01

    An introduction to the theory of stable distributions and their applications. It contains a modern outlook on the mathematical aspects of the theory. The authors explain numerous peculiarities of stable distributions and describe the principle concept of probability theory and function analysis. A significant part of the book is devoted to applications of stable distributions. Another notable feature is the material on the interconnection of stable laws with fractals, chaos and anomalous transport processes.

  5. A Note on Interpolation of Stable Processes | Nassiuma | Journal of ...

    African Journals Online (AJOL)

    Interpolation procedures tailored for gaussian processes may not be applied to infinite variance stable processes. Alternative techniques suitable for a limited set of stable case with index α∈(1,2] were initially studied by Pourahmadi (1984) for harmonizable processes. This was later extended to the ARMA stable process ...

  6. Respiratory depression by stable xenon in goats

    International Nuclear Information System (INIS)

    Winkler, S.S.

    1986-01-01

    Regional cerebral blood flow (rCBF) studies with stable xenon have recently become practical. Xenon pharmacology is thus a more than academic interest. The authors studied the respiratory response of three trained goats to a mixture of 70% xenon, 30% oxygen. The relatively high xenon concentration was used because of the animals' resistance to anesthetic effects. Two other goats were treated with equivalent anesthetic concentration of nitrous oxide and halothane. The xenon-treated animals showed respiratory depression, in contrast to the stimulating effects observed with halothane and nitrous oxide. Elevation of PaCO/sub 2/ was significant and would substantially increase cRBF. Their findings emphasize the need to monitor ventilation and respond appropriately if necessary

  7. The production of stable isotopes in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Urgel, M.; Iglesias, J.; Casas, J.; Saviron, J. M.; Quintanilla, M.

    1965-07-01

    The activities developed in the field of the production of stable isotopes by means of ion-exchange chromatography and thermal diffusion techniques are reported. The first method was used to study the separation of the nitrogen and boron isotopes, whereby the separation factor was determined by the break through method. Values ranging from 1,028 to 1,022 were obtained for the separation factor of nitrogen by using ammonium hydroxide solutions while the corresponding values as obtained for boron amounted to 1,035-1,027 using boric acid solutions. Using ammonium chloride or acetate and sodium borate, respectively, resulted in the obtention of values for the separation factor approaching unity. The isotopic separation has been carried out according to the method of development by displacement. The separation of the isotopes of the noble gases, oxygen, nitrogen and carbon has been accomplished resorting to the method of thermal diffusion. (Author) 16 refs.

  8. The uniqueness of stable crack growth data

    International Nuclear Information System (INIS)

    Smith, E.

    1981-01-01

    The paper addresses the uniqueness of the stable crack growth relation, with particular reference to creep crack growth and stress corrosion crack growth, where it is the pattern to use laboratory data which relates the stress intensity K to the crack growth rate dc/dt. Simple models are used to define the conditions under which the K versus dc/dt data is unique. Extensive use is made of the Dugdale-Bilby-Cottrell-Swinden (DBCS) model, in which the yield accompanying crack growth is assumed to be confined to an infinitesimal thin strip coplanar with the growing crack. The DBCS model can be modified to give an incremental growth criterion, which is in the form of a differential equation relating the stress intensity to crack length. The conditions under which this equation gives a unique relation between stress intensity and crack length are then investigated. (orig./HP)

  9. The production of stable isotopes in Spain

    International Nuclear Information System (INIS)

    Urgel, M.; Iglesias, J.; Casas, J.; Saviron, J. M.; Quintanilla, M.

    1965-01-01

    The activities developed in the field of the production of stable isotopes by means of ion-exchange chromatography and thermal diffusion techniques are reported. The first method was used to study the separation of the nitrogen and boron isotopes, whereby the separation factor was determined by the break through method. Values ranging from 1,028 to 1,022 were obtained for the separation factor of nitrogen by using ammonium hydroxide solutions while the corresponding values as obtained for boron amounted to 1,035-1,027 using boric acid solutions. Using ammonium chloride or acetate and sodium borate, respectively, resulted in the obtention of values for the separation factor approaching unity. The isotopic separation has been carried out according to the method of development by displacement. The separation of the isotopes of the noble gases, oxygen, nitrogen and carbon has been accomplished resorting to the method of thermal diffusion. (Author) 16 refs

  10. The Search for Stable, Massive, Elementary Particles

    International Nuclear Information System (INIS)

    Kim, Peter C.

    2001-01-01

    In this paper we review the experimental and observational searches for stable, massive, elementary particles other than the electron and proton. The particles may be neutral, may have unit charge or may have fractional charge. They may interact through the strong, electromagnetic, weak or gravitational forces or through some unknown force. The purpose of this review is to provide a guide for future searches--what is known, what is not known, and what appear to be the most fruitful areas for new searches. A variety of experimental and observational methods such as accelerator experiments, cosmic ray studies, searches for exotic particles in bulk matter and searches using astrophysical observations is included in this review

  11. Multivariate max-stable spatial processes

    KAUST Repository

    Genton, Marc G.

    2015-02-11

    Max-stable processes allow the spatial dependence of extremes to be modelled and quantified, so they are widely adopted in applications. For a better understanding of extremes, it may be useful to study several variables simultaneously. To this end, we study the maxima of independent replicates of multivariate processes, both in the Gaussian and Student-t cases. We define a Poisson process construction and introduce multivariate versions of the Smith Gaussian extreme-value, the Schlather extremal-Gaussian and extremal-t, and the Brown–Resnick models. We develop inference for the models based on composite likelihoods. We present results of Monte Carlo simulations and an application to daily maximum wind speed and wind gust.

  12. Stable computation of generalized singular values

    Energy Technology Data Exchange (ETDEWEB)

    Drmac, Z.; Jessup, E.R. [Univ. of Colorado, Boulder, CO (United States)

    1996-12-31

    We study floating-point computation of the generalized singular value decomposition (GSVD) of a general matrix pair (A, B), where A and B are real matrices with the same numbers of columns. The GSVD is a powerful analytical and computational tool. For instance, the GSVD is an implicit way to solve the generalized symmetric eigenvalue problem Kx = {lambda}Mx, where K = A{sup {tau}}A and M = B{sup {tau}}B. Our goal is to develop stable numerical algorithms for the GSVD that are capable of computing the singular value approximations with the high relative accuracy that the perturbation theory says is possible. We assume that the singular values are well-determined by the data, i.e., that small relative perturbations {delta}A and {delta}B (pointwise rounding errors, for example) cause in each singular value {sigma} of (A, B) only a small relative perturbation {vert_bar}{delta}{sigma}{vert_bar}/{sigma}.

  13. Stable Oxygen-18 and Deuterium Isotopes

    DEFF Research Database (Denmark)

    Müller, Sascha

    The application of stable Oxygen-18 (18O) and Deuterium (2H) isotopes, as a tracer for fluxes between different compartments of the water cycle was subject of the present PhD-thesis. During a three year period, temporal data from a wide range of water cycle constituents was collected from...... the Skjern River catchment, Denmark. The presented applications focused on studying the isotopic 'input signal' to the hydrosphere in the form of precipitation, the isotopic 'output signal' with its related dynamic processes at a coastal saltwater-freshwater interface (groundwater isotopes) and the temporal...... development within a given lowland headwater catchment (stream water isotopes). Based on our investigations on the precipitation isotopic composition a local meteoric water line (LMWL) was constructed and expressed as: δ2H=7.4 δ18O + 5.36‰. Moreover, we showed that under maritime temperature climate influence...

  14. A belief-based evolutionarily stable strategy.

    Science.gov (United States)

    Deng, Xinyang; Wang, Zhen; Liu, Qi; Deng, Yong; Mahadevan, Sankaran

    2014-11-21

    As an equilibrium refinement of the Nash equilibrium, evolutionarily stable strategy (ESS) is a key concept in evolutionary game theory and has attracted growing interest. An ESS can be either a pure strategy or a mixed strategy. Even though the randomness is allowed in mixed strategy, the selection probability of pure strategy in a mixed strategy may fluctuate due to the impact of many factors. The fluctuation can lead to more uncertainty. In this paper, such uncertainty involved in mixed strategy has been further taken into consideration: a belief strategy is proposed in terms of Dempster-Shafer evidence theory. Furthermore, based on the proposed belief strategy, a belief-based ESS has been developed. The belief strategy and belief-based ESS can reduce to the mixed strategy and mixed ESS, which provide more realistic and powerful tools to describe interactions among agents. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Stable orbits for lunar landing assistance

    Science.gov (United States)

    Condoleo, Ennio; Cinelli, Marco; Ortore, Emiliano; Circi, Christian

    2017-10-01

    To improve lunar landing performances in terms of mission costs, trajectory determination and visibility the use of a single probe located over an assistance orbit around the Moon has been taken into consideration. To this end, the properties of two quasi-circular orbits characterised by a stable behaviour of semi-major axis, eccentricity and inclination have been investigated. The analysis has demonstrated the possibility of using an assistance probe, located over one of these orbits, as a relay satellite between lander and Earth, even in the case of landings on the far side of the Moon. A comparison about the accuracy in retrieving the lander's state with respect to the use of a probe located in the Lagrangian point L2 of the Earth-Moon system has also been carried out.

  16. Stable glomerular filtration rate in normotensive IDDM patients with stable microalbuminuria. A 5-year prospective study

    DEFF Research Database (Denmark)

    Mathiesen, E R; Feldt-Rasmussen, B; Hommel, E

    1997-01-01

    OBJECTIVE: To investigate the long-term course of glomerular filtration rate (GFR) in IDDM patients with microalbuminuria in order to identify patients with stable or declining kidney function over a 5-year study. RESEARCH DESIGN AND METHODS: Forty normotensive (129 +/- 11/80 +/- 8 mmHg) IDDM...

  17. Stable carbides in transition metal alloys

    International Nuclear Information System (INIS)

    Piotrkowski, R.

    1991-01-01

    In the present work different techniques were employed for the identification of stable carbides in two sets of transition metal alloys of wide technological application: a set of three high alloy M2 type steels in which W and/or Mo were total or partially replaced by Nb, and a Zr-2.5 Nb alloy. The M2 steel is a high speed steel worldwide used and the Zr-2.5 Nb alloy is the base material for the pressure tubes in the CANDU type nuclear reactors. The stability of carbide was studied in the frame of Goldschmidt's theory of interstitial alloys. The identification of stable carbides in steels was performed by determining their metallic composition with an energy analyzer attached to the scanning electron microscope (SEM). By these means typical carbides of the M2 steel, MC and M 6 C, were found. Moreover, the spatial and size distribution of carbide particles were determined after different heat treatments, and both microstructure and microhardness were correlated with the appearance of the secondary hardening phenomenon. In the Zr-Nb alloy a study of the α and β phases present after different heat treatments was performed with optical and SEM metallographic techniques, with the guide of Abriata and Bolcich phase diagram. The α-β interphase boundaries were characterized as short circuits for diffusion with radiotracer techniques and applying Fisher-Bondy-Martin model. The precipitation of carbides was promoted by heat treatments that produced first the C diffusion into the samples at high temperatures (β phase), and then the precipitation of carbide particles at lower temperature (α phase or (α+β)) two phase field. The precipitated carbides were identified as (Zr, Nb)C 1-x with SEM, electron microprobe and X-ray diffraction techniques. (Author) [es

  18. Stable isotopes as tracers for radionuclides

    International Nuclear Information System (INIS)

    Giussani, A.; Bartolo, D. de; Cantone, M.C.; Zilker, T.; Greim, H.; Roth, P.; Werner, E.

    2000-01-01

    The assessment of internal dose after incorporation of radionuclides requires as input data the knowledge of the uptake into the systemic circulation, the distribution and retention in selected organs, the excretion pathways. Realistic biokinetic models are needed for reliable estimates, correct interpretation of bioassay measurements, appropriate decision-making in radiological emergencies. For many radionuclides, however, the biokinetic models currently recommended are often generic, with very few specific parameters, due to the lack of experimental human data. The use of stable isotopes as tracers enables to determine important biokinetic parameters such as the fractional uptake, the clearance from the transfer compartment, the excretion patterns under experimentally controlled conditions. The subjects investigated are not exposed to any radiation risk, so this technique enables to obtain biokinetic information also for sensitive groups of the population, such as children or pregnant women, and to determine age- and gender-specific model parameters. Sophisticated analytical method, able to discriminate and quantitate different isotopes of the same element in complex matrices such as biological fluids, have to be purposely developed and optimized. Activation analysis and mass spectrometry are the most proper techniques of choice. Experiments were conducted with molybdenum, tellurium, ruthenium and zirconium. Activation analysis with protons, thermal ionization mass spectrometry and inductively coupled mass spectrometry were employed for the determination of stable isotopes of these elements in blood plasma and urine samples. Several deviations from the predictions of the ICRP models were observed. For example, modifications to the current model for molybdenum have been suggested on the basis of these results. The dose coefficients to the target regions calculated with this proposed model are even of one order of magnitude different than the ICRP estimates

  19. Comparison of the sampling rates and partitioning behaviour of polar and non-polar contaminants in the polar organic chemical integrative sampler and a monophasic mixed polymer sampler for application as an equilibrium passive sampler.

    Science.gov (United States)

    Jeong, Yoonah; Schäffer, Andreas; Smith, Kilian

    2018-06-15

    In this work, Oasis HLB® beads were embedded in a silicone matrix to make a single phase passive sampler with a higher affinity for polar and ionisable compounds than silicone alone. The applicability of this mixed polymer sampler (MPS) was investigated for 34 aquatic contaminants (log K OW -0.03 to 6.26) in batch experiments. The influence of flow was investigated by comparing uptake under static and stirred conditions. The sampler characteristics of the MPS was assessed in terms of sampling rates (R S ) and sampler-water partition coefficients (K SW ), and these were compared to those of the polar organic chemical integrative sampler (POCIS) as a reference kinetic passive sampler. The MPS was characterized as an equilibrium sampler for both polar and non-polar compounds, with faster uptake rates and a shorter time to reach equilibrium than the POCIS. Water flow rate impacted sampling rates by up to a factor of 12 when comparing static and stirred conditions. In addition, the relative accumulation of compounds in the polyethersulfone (PES) membranes versus the inner Oasis HLB sorbent was compared for the POCIS, and ranged from <1% to 83% depending on the analyte properties. This is indicative of a potentially significant lag-phase for less polar compounds within POCIS. The findings of this study can be used to quantitatively describe the partitioning and kinetic behaviour of MPS and POCIS for a range of aquatic organic contaminants for application in field sampling. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Understanding GaN/InGaN core–shell growth towards high quality factor whispering gallery modes from non-polar InGaN quantum wells on GaN rods

    Science.gov (United States)

    Tessarek, C.; Rechberger, S.; Dieker, C.; Heilmann, M.; Spiecker, E.; Christiansen, S.

    2017-12-01

    GaN microrods are used as a basis for subsequent InGaN quantum well (QW) and quantum dot deposition by metal-organic vapor phase epitaxy. The coverage of the shell along the sidewall of rods is dependent on the rod growth time and a complete coverage is obtained for shorter rod growth times. Transmission electron microscopy measurements are performed to reveal the structural properties of the InGaN layer on the sidewall facet and on the top facet. The presence of layers in the microrod and on the microrod surface will be discussed with respect to GaN and InGaN growth. A detailed model will be presented explaining the formation of multiple SiN layers and the partial and full coverage of the shell around the core. Cathodoluminescence measurements are performed to analyze the InGaN emission properties along the microrod and to study the microresonator properties of such hexagonal core–shell structures. High quality factor whispering gallery modes with Q∼ 1200 are reported for the first time in a GaN microrod/InGaN non-polar QW core–shell geometry. The GaN/InGaN core–shell microrods are expected to be promising building blocks for low-threshold laser diodes and ultra-sensitive optical sensors.

  1. Understanding GaN/InGaN core-shell growth towards high quality factor whispering gallery modes from non-polar InGaN quantum wells on GaN rods.

    Science.gov (United States)

    Tessarek, C; Rechberger, S; Dieker, C; Heilmann, M; Spiecker, E; Christiansen, S

    2017-12-01

    GaN microrods are used as a basis for subsequent InGaN quantum well (QW) and quantum dot deposition by metal-organic vapor phase epitaxy. The coverage of the shell along the sidewall of rods is dependent on the rod growth time and a complete coverage is obtained for shorter rod growth times. Transmission electron microscopy measurements are performed to reveal the structural properties of the InGaN layer on the sidewall facet and on the top facet. The presence of layers in the microrod and on the microrod surface will be discussed with respect to GaN and InGaN growth. A detailed model will be presented explaining the formation of multiple SiN layers and the partial and full coverage of the shell around the core. Cathodoluminescence measurements are performed to analyze the InGaN emission properties along the microrod and to study the microresonator properties of such hexagonal core-shell structures. High quality factor whispering gallery modes with [Formula: see text] are reported for the first time in a GaN microrod/InGaN non-polar QW core-shell geometry. The GaN/InGaN core-shell microrods are expected to be promising building blocks for low-threshold laser diodes and ultra-sensitive optical sensors.

  2. Building Footprints, Primarily residential, at risk buildings such as hospitals, nursing homes, etc for use in Emergency Management Hazard Mitigation planning., Published in 2010, 1:4800 (1in=400ft) scale, Carroll County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Building Footprints dataset current as of 2010. Primarily residential, at risk buildings such as hospitals, nursing homes, etc for use in Emergency Management Hazard...

  3. Stability properties of nonlinear dynamical systems and evolutionary stable states

    Energy Technology Data Exchange (ETDEWEB)

    Gleria, Iram, E-mail: iram@fis.ufal.br [Instituto de Física, Universidade Federal de Alagoas, 57072-970 Maceió-AL (Brazil); Brenig, Leon [Faculté des Sciences, Université Libre de Bruxelles, 1050 Brussels (Belgium); Rocha Filho, Tarcísio M.; Figueiredo, Annibal [Instituto de Física and International Center for Condensed Matter Physics, Universidade de Brasília, 70919-970 Brasília-DF (Brazil)

    2017-03-18

    Highlights: • We address the problem of equilibrium stability in a general class of non-linear systems. • We link Evolutionary Stable States (ESS) to stable fixed points of square quasi-polynomial (QP) systems. • We show that an interior ES point may be related to stable interior fixed points of QP systems. - Abstract: In this paper we address the problem of stability in a general class of non-linear systems. We establish a link between the concepts of asymptotic stable interior fixed points of square Quasi-Polynomial systems and evolutionary stable states, a property of some payoff matrices arising from evolutionary games.

  4. Influence of horse stable environment on human airways

    Directory of Open Access Journals (Sweden)

    Pringle John

    2009-05-01

    Full Text Available Abstract Background Many people spend considerable amount of time each day in equine stable environments either as employees in the care and training of horses or in leisure activity. However, there are few studies available on how the stable environment affects human airways. This study examined in one horse stable qualitative differences in indoor air during winter and late summer conditions and assessed whether air quality was associated with clinically detectable respiratory signs or alterations to selected biomarkers of inflammation and lung function in stable personnel. Methods The horse stable environment and stable-workers (n = 13 in one stable were investigated three times; first in the winter, second in the interjacent late summer and the third time in the following winter stabling period. The stable measurements included levels of ammonia, hydrogen sulphide, total and respirable dust, airborne horse allergen, microorganisms, endotoxin and glucan. The stable-workers completed a questionnaire on respiratory symptoms, underwent nasal lavage with subsequent analysis of inflammation markers, and performed repeated measurements of pulmonary function. Results Measurements in the horse stable showed low organic dust levels and high horse allergen levels. Increased viable level of fungi in the air indicated a growing source in the stable. Air particle load as well as 1,3-β-glucan was higher at the two winter time-points, whereas endotoxin levels were higher at the summer time-point. Two stable-workers showed signs of bronchial obstruction with increased PEF-variability, increased inflammation biomarkers relating to reported allergy, cold or smoking and reported partly work-related symptoms. Furthermore, two other stable-workers reported work-related airway symptoms, of which one had doctor's diagnosed asthma which was well treated. Conclusion Biomarkers involved in the development of airway diseases have been studied in relation to

  5. Stable isotope analysis in primatology: a critical review.

    Science.gov (United States)

    Sandberg, Paul A; Loudon, James E; Sponheimer, Matt

    2012-11-01

    Stable isotope analysis has become an important tool in ecology over the last 25 years. A wealth of ecological information is stored in animal tissues in the relative abundances of the stable isotopes of several elements, particularly carbon and nitrogen, because these isotopes navigate through ecological processes in predictable ways. Stable carbon and nitrogen isotopes have been measured in most primate taxonomic groups and have yielded information about dietary content, dietary variability, and habitat use. Stable isotopes have recently proven useful for addressing more fine-grained questions about niche dynamics and anthropogenic effects on feeding ecology. Here, we discuss stable carbon and nitrogen isotope systematics and critically review the published stable carbon and nitrogen isotope data for modern primates with a focus on the problems and prospects for future stable isotope applications in primatology. © 2012 Wiley Periodicals, Inc.

  6. Tungsten Stable Isotope Compositions of Ferromanganese Crusts

    Science.gov (United States)

    Abraham, K.; Barling, J.; Hein, J. R.; Schauble, E. A.; Halliday, A. N.

    2014-12-01

    We report the first accurate and precise data for mass-dependent fractionation of tungsten (W) stable isotopes, using a double spike technique and MC-ICPMS. Results are expressed relative to the NIST 3136 W isotope standard as per mil deviations in 186W/184W (δ186W). Although heavy element mass-dependent fractionations are expected to be small, Tl and U both display significant low temperature isotopic fractionations. Theoretical calculations indicate that W nuclear volume isotopic effects should be smaller than mass-dependent fractionations at low temperatures. Hydrogenetic ferromanganese (Fe-Mn) crusts precipitate directly from seawater and have been used as paleoceanographic recorders of temporal changes in seawater chemistry. Crusts are strongly enriched in W and other metals, and are a promising medium for exploring W isotopic variability. Tungsten has a relatively long residence time in seawater of ~61,000 years, mainly as the tungstate ion (WO42-). Water depth profiles show conservative behaviour. During adsorption on Fe-Mn crusts, W species form inner-sphere complexes in the hexavalent (W6+) state. The major host phase is thought to be Mn oxides and the lighter W isotope is expected to be absorbed preferentially. Surface scrapings of 13 globally distributed hydrogenetic Fe-Mn crusts display δ186W from -0.08 to -0.22‰ (±0.03‰, 2sd). A trend toward lighter W isotope composition exists with increasing water depth (~1500 to ~5200m) and W concentration. One hydrothermal Mn-oxide sample is anomalously light and Mn nodules are both heavy and light relative to Fe-Mn crusts. Tungsten speciation depends on concentration, pH, and time in solution and is not well understood because of the extremely slow kinetics of the reactions. In addition, speciation of aqueous and/or adsorbed species might be sensitive to pressure, showing similar thermodynamic stability but different effective volumes. Thus, W stable isotopes might be used as a water-depth barometer in

  7. Stable nuclear transformation of Eudorina elegans

    Directory of Open Access Journals (Sweden)

    Lerche Kai

    2013-02-01

    Full Text Available Abstract Background A fundamental step in evolution was the transition from unicellular to differentiated, multicellular organisms. Volvocine algae have been used for several decades as a model lineage to investigate the evolutionary aspects of multicellularity and cellular differentiation. There are two well-studied volvocine species, a unicellular alga (Chlamydomonas reinhardtii and a multicellular alga with differentiated cell types (Volvox carteri. Species with intermediate characteristics also exist, which blur the boundaries between unicellularity and differentiated multicellularity. These species include the globular alga Eudorina elegans, which is composed of 16–32 cells. However, detailed molecular analyses of E. elegans require genetic manipulation. Unfortunately, genetic engineering has not yet been established for Eudorina, and only limited DNA and/or protein sequence information is available. Results Here, we describe the stable nuclear transformation of E. elegans by particle bombardment using both a chimeric selectable marker and reporter genes from different heterologous sources. Transgenic algae resistant to paromomycin were achieved using the aminoglycoside 3′-phosphotransferase VIII (aphVIII gene of Streptomyces rimosus, an actinobacterium, under the control of an artificial promoter consisting of two V. carteri promoters in tandem. Transformants exhibited an increase in resistance to paromomycin by up to 333-fold. Co-transformation with non-selectable plasmids was achieved with a rate of 50 - 100%. The luciferase (gluc gene from the marine copepod Gaussia princeps, which previously was engineered to match the codon usage of C. reinhardtii, was used as a reporter gene. The expression of gluc was mediated by promoters from C. reinhardtii and V. carteri. Heterologous heat shock promoters induced an increase in luciferase activity (up to 600-fold at elevated temperatures. Long-term stability and both constitutive and

  8. Introducing Stable Radicals into Molecular Machines.

    Science.gov (United States)

    Wang, Yuping; Frasconi, Marco; Stoddart, J Fraser

    2017-09-27

    Ever since their discovery, stable organic radicals have received considerable attention from chemists because of their unique optical, electronic, and magnetic properties. Currently, one of the most appealing challenges for the chemical community is to develop sophisticated artificial molecular machines that can do work by consuming external energy, after the manner of motor proteins. In this context, radical-pairing interactions are important in addressing the challenge: they not only provide supramolecular assistance in the synthesis of molecular machines but also open the door to developing multifunctional systems relying on the various properties of the radical species. In this Outlook, by taking the radical cationic state of 1,1'-dialkyl-4,4'-bipyridinium (BIPY •+ ) as an example, we highlight our research on the art and science of introducing radical-pairing interactions into functional systems, from prototypical molecular switches to complex molecular machines, followed by a discussion of the (i) limitations of the current systems and (ii) future research directions for designing BIPY •+ -based molecular machines with useful functions.

  9. Canonical, stable, general mapping using context schemes.

    Science.gov (United States)

    Novak, Adam M; Rosen, Yohei; Haussler, David; Paten, Benedict

    2015-11-15

    Sequence mapping is the cornerstone of modern genomics. However, most existing sequence mapping algorithms are insufficiently general. We introduce context schemes: a method that allows the unambiguous recognition of a reference base in a query sequence by testing the query for substrings from an algorithmically defined set. Context schemes only map when there is a unique best mapping, and define this criterion uniformly for all reference bases. Mappings under context schemes can also be made stable, so that extension of the query string (e.g. by increasing read length) will not alter the mapping of previously mapped positions. Context schemes are general in several senses. They natively support the detection of arbitrary complex, novel rearrangements relative to the reference. They can scale over orders of magnitude in query sequence length. Finally, they are trivially extensible to more complex reference structures, such as graphs, that incorporate additional variation. We demonstrate empirically the existence of high-performance context schemes, and present efficient context scheme mapping algorithms. The software test framework created for this study is available from https://registry.hub.docker.com/u/adamnovak/sequence-graphs/. anovak@soe.ucsc.edu Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  10. Chemically Stable Lipids for Membrane Protein Crystallization

    Energy Technology Data Exchange (ETDEWEB)

    Ishchenko, Andrii; Peng, Lingling; Zinovev, Egor; Vlasov, Alexey; Lee, Sung Chang; Kuklin, Alexander; Mishin, Alexey; Borshchevskiy, Valentin; Zhang, Qinghai; Cherezov, Vadim (MIPT); (USC); (Scripps)

    2017-05-01

    The lipidic cubic phase (LCP) has been widely recognized as a promising membrane-mimicking matrix for biophysical studies of membrane proteins and their crystallization in a lipidic environment. Application of this material to a wide variety of membrane proteins, however, is hindered due to a limited number of available host lipids, mostly monoacylglycerols (MAGs). Here, we designed, synthesized, and characterized a series of chemically stable lipids resistant to hydrolysis, with properties complementary to the widely used MAGs. In order to assess their potential to serve as host lipids for crystallization, we characterized the phase properties and lattice parameters of mesophases made of two most promising lipids at a variety of different conditions by polarized light microscopy and small-angle X-ray scattering. Both lipids showed remarkable chemical stability and an extended LCP region in the phase diagram covering a wide range of temperatures down to 4 °C. One of these lipids has been used for crystallization and structure determination of a prototypical membrane protein bacteriorhodopsin at 4 and 20 °C.

  11. 26 S proteasomes function as stable entities

    DEFF Research Database (Denmark)

    Hendil, Klavs B; Hartmann-Petersen, Rasmus; Tanaka, Keiji

    2002-01-01

    , shuttles between a free state and the 26-S proteasome, bringing substrate to the complex. However, S5a was not found in the free state in HeLa cells. Besides, all subunits in PA700, including S5a, exchanged at similar low rates. It therefore seems that 26-S proteasomes function as stable entities during...... dissociate and reassemble during initiation of protein degradation in a ternary complex with the substrate, as in the dissociation-reassembly cycles found for ribosomes and the chaperonin GroEL/GroES. Here we followed disassembly and assembly of 26-S proteasomes in cell extracts as the exchange of PA700...... subunits between mouse and human 26-S proteasomes. Compared to the rate of proteolysis in the same extract, the disassembly-reassembly cycle was much too slow to present an obligatory step in a degradation cycle. It has been suggested that subunit S5a (Mcb1, Rpn10), which binds poly-ubiquitin substrates...

  12. Migration, fertility, and aging in stable populations.

    Science.gov (United States)

    Alho, Juha M

    2008-08-01

    Fertility is below replacement level in all European countries, and population growth is expected to decline in the coming decades. Increasing life expectancy will accentuate concomitant aging of the population. Migration has been seen as a possible means to decelerate aging. In this article, I introduce a stable, open-population model in which cohort net migration is proportional to births. In this case, the migration-fertility trade-off can be studied with particular ease. I show that although migration can increase the growth rate, which tends to make the age distribution younger, it also has an opposite effect because of its typical age pattern. I capture the effect of the age pattern of net migration in a migration-survivor function. The effect of net migration on growth is quantified with data from 17 European countries. I show that some countries already have a level of migration that will lead to stationarity. For other countries with asymptotically declining population, migration still provides opportunities for slowing down aging of the population as a whole.

  13. Shelf-stable foods through irradiation processing

    International Nuclear Information System (INIS)

    1995-11-01

    This survey has been produced from a database on analytical reference materials of biological and environmental origin, which is maintained at the International Atomic Energy Agency. It is an updated version of earlier reports, the last published in 1990. The information presented refers mostly to reference materials for trace element constituents; however, information is also included on a number of other selected measurands of relevance to IAEA programmes, i.e. radionuclides, stable isotopes, anions, cations, organometallic compounds and organic contaminants. The database presently contains over 10,000 analyte values for 455 measurands in 650 reference materials produced by 30 different suppliers. Additional information on the cost of the materials, the unit size supplied, and recommended minimum weight of material for analysis is also provided, if this information is available to the authors. It is expected that this survey will help analysts to select reference materials for quality assurance purposes that match as closely as possible, with respect to matrix type and concentrations of the measurands of interest, their samples to be analyzed. 22 refs, 2 tabs

  14. STABLE ISOTOPE GEOCHEMISTRY OF MASSIVE ICE

    Directory of Open Access Journals (Sweden)

    Yurij K. Vasil’chuk

    2016-01-01

    Full Text Available The paper summarises stable-isotope research on massive ice in the Russian and North American Arctic, and includes the latest understanding of massive-ice formation. A new classification of massive-ice complexes is proposed, encompassing the range and variabilityof massive ice. It distinguishes two new categories of massive-ice complexes: homogeneousmassive-ice complexes have a similar structure, properties and genesis throughout, whereasheterogeneous massive-ice complexes vary spatially (in their structure and properties andgenetically within a locality and consist of two or more homogeneous massive-ice bodies.Analysis of pollen and spores in massive ice from Subarctic regions and from ice and snow cover of Arctic ice caps assists with interpretation of the origin of massive ice. Radiocarbon ages of massive ice and host sediments are considered together with isotope values of heavy oxygen and deuterium from massive ice plotted at a uniform scale in order to assist interpretation and correlation of the ice.

  15. LHC Report: Towards stable beams and collisions

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    Over the past two weeks, the LHC re-commissioning with beam has continued at a brisk pace. The first collisions of 2011 were produced on 2 March, with stable beams and collisions for physics planned for the coming days. Low intensity beams with just a few bunches of particles were used to test the energy ramp to 3.5 TeV and the squeeze. The results were successful and, as a by-product, the first collisions of 2011 were recorded 2 March. One of the main activities carried out by the operation teams has been the careful set-up of the collimation system, and the injection and beam dump protection devices. The collimation system provides essential beam cleaning, preventing stray particles from impacting other elements of the machine, particularly the superconducting magnets. In addition to the collimation system, also the injection and beam dump protection devices perform a vital machine protection role, as they detect any beam that might be mis-directed during rare, but not totally unavoidable, hardware hiccups...

  16. Stable Isotope Group 1984 progress report

    International Nuclear Information System (INIS)

    Lyon, G.L.

    1985-04-01

    The work of the group in 1984 is described and includes studies in isotope geology, isotope hydrology, geochronology, isotope biology and mass spectrometer instrumentation. Geothermal studies have decreased compared to other years, but major data summaries were made for Wairakei and Ngawha. The hydrology of Whakarewarewa and Rotorua is being elucidated using water isotopes. Models of the subsurface flows at Kawerau and Ngawha are being made to relate fluid to mineral isotope compositions. A study of the δ 13 C and δ 34 S compositions of New Zealand oils has been started. Groups of oils of related origin are being defined, and compositions will be compared with those of potential source rocks. A method was developed for isotope analysis of sulphur in rocks. The isotopic composition of water is being used to identify and characterise groundwater aquifers in the Wairarapa and at Poverty Bay. Stable carbon isotopes have been used to identify food sources for invertebrates, and to show biochemical pathways in lactation by cows. The geochronology group is involved in major studies in Antarctica, using U-Pb, Rb-Sr and K-Ar methods. Rocks from North Victoria Land, Marie Byrd Land and the USARP mountains are being compared with possible correlatives in New Zealand and Argentina. Strontium isotope data is being applied to the origin of magmas in several regions of New Zealand. The K-Ar data is being stored on computer files. Fission track measurements are being applied to unravel uplift histories in Westland and Taranaki

  17. Embryotoxicity of stable isotopes and use of stable isotopes in studies of teratogenetic mechanisms

    International Nuclear Information System (INIS)

    Spielmann, H.; Nau, H.

    1986-01-01

    Experiments on teratogenic effects of stable isotopes from our own and other laboratories are evaluated. In the first series of investigations, the enrichment of the stable isotope 13 C derived from U- 13 C-glucose was studied in mouse embryos at various stages of development, including limb buds in organ culture. Preimplantation mouse embryos incubated in vitro in 13 C-enriched medium for 48 hours showed normal development during subsequent differentiation in vitro and also in vivo after embryo transfer to faster mothers. These embryos were 15% to 20% enriched in 13 C. Administration of U-13-C-glucose to pregnant mice during organogenesis led to an increase of the absolute 13 C content of the embryo for several days after the end of isotope administration, whereas the enrichment in maternal tissue decreased. No alterations of embryonic development were detected due to stable isotope enrichment. Development of cultured mouse limb buds was unaffected by incubation with 82 mol% U- 13 C-glucose as judged from morphologic and biochemical criteria. The second part of the article describes the value of deuterium-labeled drugs as probes into the mechanism of activation of teratogenic metabolites. A comparison of the pharmacokinetics as well as the teratogenicity between cyclophosphamide and some specific deuterium-labeled analogues showed that the isotope effect observed can be related to a particular metabolic pathway crucial for teratogenic activation by this drug

  18. [Angle-stable fixation of intramedullary nails using the Angular Stable Locking System® (ASLS)].

    Science.gov (United States)

    Höntzsch, D; Blauth, M; Attal, R

    2011-12-01

    Greater stability in intramedullary osteosynthesis using angle-stable fixation with intramedullary nails and proximal locking screws. A novel screw-and-sleeve system (ASLS®, Synthes GmbH, Oberdorf, Switzerland) is applied using normal cannulated nails. Decisions can be made intraoperatively. This technology widens the range of indications for intramedullary nailing: The smaller and less stable the fragment requiring fixation, the greater the indication for angular stable fixation of the proximal and/or distal fragment. Femoral, tibial and humeral fractures, intramedullary osteosynthesis in osteoporotic bone and ante- and retrograde nailing. Particularly in the case of retrograde nailing, sustained prevention of nail toggling is achieved. None. Drill with the first drill bit, which has the same core diameter as the screw shaft. Drill the cortex to the external diameter of the sleeve. Place the sleeve on the tip of the screw. The screw-sleeve combination is then advanced through the larger near hole until the sleeve-covered screw tip sits in the locking hole of the intramedullary fixation nail. Advance the screw. As the screw diameter becomes larger, the sleeve expands resulting in an angular stable locking effect. The screw is then advanced until the head of the screw sits on the exposed surface of the cortex. The hole is filled with the expanded part of the screw shaft beneath the screw head. The necessary 1-3 turns are cut by the self-tapping flute on the screw. According to experience to date, this form of angle-stable fixation enables earlier and/or greater partial mobilization or earlier full mobilization. In all other respects, the guidelines for aftercare in intramedullary nailing apply. A multi-center pilot study has shown the technique to be reproducible and simple. There have been no complications using this technique to date. Biomechanical laboratory studies have demonstrated that stability with respect to axial and torsional loading is statically and

  19. Unit of stable isotopic N15 analysis

    International Nuclear Information System (INIS)

    Cabrera de Bisbal, Evelin; Paredes U, Maria

    1997-01-01

    The continuous and growing demand of crops and cattle for the domestic inhabitants, forces the search of technical solutions in agriculture. One of the solutions able to be covered in a near future it is the escalation of agricultural production in lands already being cultivated, either by means of an intensification of cultivation and / or increasing the unitary yields. In the intensive cropping systems, the crops extract substantial quantities of nutriments that is recovered by means of the application of fertilizers. Due to the lack of resources and to the increase of commercial inputs prices, it has been necessary to pay attention to the analysis and improvement of low inputs cropping systems and to the effective use of resources. Everything has made to establish a concept of plant nutrition focused system, which integrate the sources of nutriments for plants and the production factors of crops in a productive cropping system, to improve the fertility of soils, the agricultural productivity and profitability. This system includes the biggest efficiency of chemical fertilizers as the maximum profit of alternative sources of nutriments, such as organic fertilizers, citrate-phosphate rocks and biological nitrogen fixation. By means of field experiments under different environmental conditions (soils and climate) it can be determined the best combination of fertilizers practice (dose, placement, opportunity and source) for selected cropping systems. The experimentation with fertilizer, marked with stable and radioactive isotopes, provides a direct and express method to obtain conclusive answers to the questions: where, when and how should be applied. The fertilizers marked with N 1 5 have been used to understand the application of marked fertilizer to the cultivations, and the determination of the proportion of crops nutritious element derived from fertilizer. The isotopic techniques offer a fast and reliable mean to obtain information about the distribution of

  20. How structurally stable are global socioeconomic systems?

    Science.gov (United States)

    Saavedra, Serguei; Rohr, Rudolf P; Gilarranz, Luis J; Bascompte, Jordi

    2014-11-06

    The stability analysis of socioeconomic systems has been centred on answering whether small perturbations when a system is in a given quantitative state will push the system permanently to a different quantitative state. However, typically the quantitative state of socioeconomic systems is subject to constant change. Therefore, a key stability question that has been under-investigated is how strongly the conditions of a system itself can change before the system moves to a qualitatively different behaviour, i.e. how structurally stable the systems is. Here, we introduce a framework to investigate the structural stability of socioeconomic systems formed by a network of interactions among agents competing for resources. We measure the structural stability of the system as the range of conditions in the distribution and availability of resources compatible with the qualitative behaviour in which all the constituent agents can be self-sustained across time. To illustrate our framework, we study an empirical representation of the global socioeconomic system formed by countries sharing and competing for multinational companies used as proxy for resources. We demonstrate that the structural stability of the system is inversely associated with the level of competition and the level of heterogeneity in the distribution of resources. Importantly, we show that the qualitative behaviour of the observed global socioeconomic system is highly sensitive to changes in the distribution of resources. We believe that this work provides a methodological basis to develop sustainable strategies for socioeconomic systems subject to constantly changing conditions. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  1. Stable gastric pentadecapeptide BPC 157 and bupivacaine.

    Science.gov (United States)

    Zivanovic-Posilovic, Gordana; Balenovic, Diana; Barisic, Ivan; Strinic, Dean; Stambolija, Vasilije; Udovicic, Mario; Uzun, Sandra; Drmic, Domagoj; Vlainic, Josipa; Bencic, Martina Lovric; Sindic, Aleksandra; Seiwerth, Sven; Sikiric, Predrag

    2016-12-15

    Bupivacaine toxicity following accidental overdose still lacks therapeutic solution. However, there are major arguments for testing BPC 157 against bupivacaine toxicity in vivo in rats, in particular, and then finally, in vitro. These are: the lack of any known BPC 157 toxicity, a lifesaving effect via the mitigation of arrhythmias in rats underwent hyperkalemia or digitalis toxicity, the elimination of hyperkalemia and arrhythmias in rats underwent succinylcholine toxicity and finally, the reduction of potassium-induced depolarization in vitro (in HEK293 cells) in severe hyperkalemia. Most importantly, BPC 157 successfully prevents and counteracts bupivacaine cardiotoxicity; BPC 157 is effective even against the worst outcomes such as a severely prolonged QRS complex. Here, rats injected with bupivacaine (100mg/kg IP) exhibited bradycardia, AV-block, ventricular ectopies, ventricular tachycardia, T-wave elevation and asystole. All of the fatalities had developed T-wave elevation, high-degree AV-block, respiratory arrest and asystole. These were largely counteracted by BPC 157 administration (50µg/kg, 10µg/kg, 10ng/kg, or 10pg/kg IP) given 30min before or 1min after the bupivacaine injection. When BPC 157 was given 6min after bupivacaine administration, and after the development of prolonged QRS intervals (20ms), the fatal outcome was markedly postponed. Additionally, the effect of bupivacaine on cell membrane depolarization was explored by measuring membrane voltages (Vm) in HEK293 cells. Bupivacaine (1mM) alone caused depolarization of the cells, while in combination with BPC 157 (1µm), the bupivacaine-induced depolarization was inhibited. Together, these findings suggest that the stable gastric pentadecapeptide BPC 157 should be a potential antidote for bupivacaine cardiotoxicity. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Stable colloids in molten inorganic salts

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hao; Dasbiswas, Kinjal; Ludwig, Nicholas B.; Han, Gang; Lee, Byeongdu; Vaikuntanathan, Suri; Talapin, Dmitri V.

    2017-02-15

    A colloidal solution is a homogeneous dispersion of particles or droplets of one phase (solute) in a second, typically liquid, phase (solvent). Colloids are ubiquitous in biological, chemical and technological processes1, 2, homogenizing highly dissimilar constituents. To stabilize a colloidal system against coalescence and aggregation, the surface of each solute particle is engineered to impose repulsive forces strong enough to overpower van der Waals attraction and keep the particles separated from each other2. Electrostatic stabilization3, 4 of charged solutes works well in solvents with high dielectric constants, such as water (dielectric constant of 80). In contrast, colloidal stabilization in solvents with low polarity, such as hexane (dielectric constant of about 2), can be achieved by decorating the surface of each particle of the solute with molecules (surfactants) containing flexible, brush-like chains2, 5. Here we report a class of colloidal systems in which solute particles (including metals, semiconductors and magnetic materials) form stable colloids in various molten inorganic salts. The stability of such colloids cannot be explained by traditional electrostatic and steric mechanisms. Screening of many solute–solvent combinations shows that colloidal stability can be traced to the strength of chemical bonding at the solute–solvent interface. Theoretical analysis and molecular dynamics modelling suggest that a layer of surface-bound solvent ions produces long-ranged charge-density oscillations in the molten salt around solute particles, preventing their aggregation. Colloids composed of inorganic particles in inorganic melts offer opportunities for introducing colloidal techniques to solid-state science and engineering applications.

  3. Stable configurations of graphene on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Javvaji, Brahmanandam; Shenoy, Bhamy Maithry [Department of Aerospace Engineering, Indian Institute of Science, Bangalore 560012 (India); Mahapatra, D. Roy, E-mail: droymahapatra@aero.iisc.ernet.in [Department of Aerospace Engineering, Indian Institute of Science, Bangalore 560012 (India); Ravikumar, Abhilash [Department of Metallurgical and Materials Engineering, National Institute of Technology Karnataka, Surathkal 575025 (India); Hegde, G.M. [Center for Nano Science and Engineering, Indian Institute of Science, Bangalore 560012 (India); Rizwan, M.R. [Department of Metallurgical and Materials Engineering, National Institute of Technology Karnataka, Surathkal 575025 (India)

    2017-08-31

    Highlights: • Simulations of epitaxial growth process for silicon–graphene system is performed. • Identified the most favourable orientation of graphene sheet on silicon substrate. • Atomic local strain due to the silicon–carbon bond formation is analyzed. - Abstract: Integration of graphene on silicon-based nanostructures is crucial in advancing graphene based nanoelectronic device technologies. The present paper provides a new insight on the combined effect of graphene structure and silicon (001) substrate on their two-dimensional anisotropic interface. Molecular dynamics simulations involving the sub-nanoscale interface reveal a most favourable set of temperature independent orientations of the monolayer graphene sheet with an angle of ∽15° between its armchair direction and [010] axis of the silicon substrate. While computing the favorable stable orientations, both the translation and the rotational vibrations of graphene are included. The possible interactions between the graphene atoms and the silicon atoms are identified from their coordination. Graphene sheet shows maximum bonding density with bond length 0.195 nm and minimum bond energy when interfaced with silicon substrate at 15° orientation. Local deformation analysis reveals probability distribution with maximum strain levels of 0.134, 0.047 and 0.029 for 900 K, 300 K and 100 K, respectively in silicon surface for 15° oriented graphene whereas the maximum probable strain in graphene is about 0.041 irrespective of temperature. Silicon–silicon dimer formation is changed due to silicon–carbon bonding. These results may help further in band structure engineering of silicon–graphene lattice.

  4. Stable Continental Region Earthquakes in South China

    Science.gov (United States)

    Liu, L.

    This paper reviews some remarkable characteristics of earthquakes in a Stable Continental Region (SCR) of the South China Block (SCB). The kernel of the SCB is the Yangtze platform solidified in late Proterozoic time, with continental growth to the southeast by a series of fold belts in Paleozoic time. The facts that the deviatoric stress is low, the orientations of the major tectonic features in the SCB are substantially normal to the maximum horizontal principal stress, and a relatively uniform crust, seem to be the major reasons for lack of significant seismicity in most regions of the SCB. Earthquakes in this region are mainly associated with three seismic zones: (1) the Southeast China Coast seismic zone related to Guangdong-Fujian coastal folding belt (associated with Eurasia-Philippine Sea plate collision); (2) the Southern Yellow Sea seismic zone associated with continental shelf rifts and basins; and (3) the Downstream Yangtze River seismic zone spatially coinciding with Tertiary rifts and basin development. All three seismic zones are close to one or two major economic and population centers in the SCB so that they pose significant seismic hazards. Earthquake focal mechanisms in the SCB are consistent with strike-slip to normal faulting stress regimes. Because of the global and national economic significance of the SCB and its dense population, the seismic hazard of the region is of outstanding importance. Comparing the SCB with another less developed region, a pending earthquake with the same size and tectonic setting would cause substantially more severe social and economic losses in the SCB. This paper also compiles an inventory of historic moderate to great earthquakes in the SCB; most of the data are not widely available in English literature.

  5. Tempered stable distributions stochastic models for multiscale processes

    CERN Document Server

    Grabchak, Michael

    2015-01-01

    This brief is concerned with tempered stable distributions and their associated Levy processes. It is a good text for researchers interested in learning about tempered stable distributions.  A tempered stable distribution is one which takes a stable distribution and modifies its tails to make them lighter. The motivation for this class comes from the fact that infinite variance stable distributions appear to provide a good fit to data in a variety of situations, but the extremely heavy tails of these models are not realistic for most real world applications. The idea of using distributions that modify the tails of stable models to make them lighter seems to have originated in the influential paper of Mantegna and Stanley (1994). Since then, these distributions have been extended and generalized in a variety of ways. They have been applied to a wide variety of areas including mathematical finance, biostatistics,computer science, and physics.

  6. Absolute Continuity of Stable Foliations for Mappings of Banach Spaces

    Science.gov (United States)

    Blumenthal, Alex; Young, Lai-Sang

    2017-09-01

    We prove the absolute continuity of stable foliations for mappings of Banach spaces satisfying conditions consistent with time- t maps of certain classes of dissipative PDEs. This property is crucial for passing information from submanifolds transversal to the stable foliation to the rest of the phase space; it is also used in proofs of ergodicity. Absolute continuity of stable foliations is well known in finite dimensional hyperbolic theory. On Banach spaces, the absence of nice geometric properties poses some additional difficulties.

  7. Tukey max-stable processes for spatial extremes

    KAUST Repository

    Xu, Ganggang

    2016-09-21

    We propose a new type of max-stable process that we call the Tukey max-stable process for spatial extremes. It brings additional flexibility to modeling dependence structures among spatial extremes. The statistical properties of the Tukey max-stable process are demonstrated theoretically and numerically. Simulation studies and an application to Swiss rainfall data indicate the effectiveness of the proposed process. © 2016 Elsevier B.V.

  8. Stable SU(5) monopoles with higher magnetic charge

    International Nuclear Information System (INIS)

    Miyamoto, S.; Sato, H.; Tomohiro, S.

    1985-01-01

    Taking into account the electroweak breaking effects, some multiply charged monopoles were shown to be stable by Gardner and Harvey. We give the explicit Ansa$uml: tze for finite-energy, nonsingular solutions of these stable higher-strength monopoles with eg = 1,(3/2),3. We also give the general stability conditions and the detailed behavior of the interaction potentials between two monopoles which produce the stable higher-strength monopoles

  9. Sense of Humor, Stable Affect, and Psychological Well-Being

    Directory of Open Access Journals (Sweden)

    Arnie Cann

    2014-08-01

    Full Text Available A good sense of humor has been implicated as a quality that could contribute to psychological well-being. The mechanisms through which sense of humor might operate include helping to reappraise threats, serving as a character strength, or facilitating happiness. The current research attempts to integrate these possibilities by examining whether a good sense of humor might operate globally by helping to maintain a more stable positive affect. Stable positive affect has been shown to facilitate more effective problem solving and to build resilience. However, not all humor is adaptive humor, so we also examine the roles that different styles of humor use might play. Individual differences in humor styles were used to predict stable levels of affect. Then, in a longitudinal design, humor styles and stable affect were used to predict subsequent resilience and psychological health. The results indicated that stable affect was related to resilience and psychological well-being, and that a sense of humor that involves self-enhancing humor, humor based on maintaining a humorous perspective about one’s experiences, was positively related to stable positive affect, negatively related to stable negative affect, and was mediated through stable affect in influencing resilience, well-being and distress. Thus, while a good sense of humor can lead to greater resilience and better psychological health, the current results, focusing on stable affect, find only self-enhancing humor provides reliable benefits.

  10. Stable glomerular filtration rate in normotensive IDDM patients with stable microalbuminuria. A 5-year prospective study

    DEFF Research Database (Denmark)

    Mathiesen, E R; Feldt-Rasmussen, B; Hommel, E

    1997-01-01

    . Out of 40 patients, 14 progressed to diabetic nephropathy (UAE > 300 mg/24 h). These patients had a significant reduction in GFR (mean -2.2 +/- 3.8 ml x min-1 x year-1; P = 0.05), while GFR remained stable in the remaining 26 patients with nonprogressive microalbuminuria (change in GFR 0.5 +/- 2.1 ml...... x min-1 x year-1; NS). The difference in the rate of decline of GFR was significant (mean 2.7 ml x min-1 x year-1; P

  11. Passage rates in poultry digestion using stable isotope markers and INAA

    International Nuclear Information System (INIS)

    Dunkley, C.S.; Kim, W.K.; Ricke, S.C.; James, W.D.; Ellis, W.C.; McReynolds, J.L.; Kubena, L.F.; Nisbet, D.J.

    2008-01-01

    A method has been developed for the study of passage rates and mean residence times (MRT) of test rations through the gastrointestinal tracts of layer hens. The use of rare earth elements as stable indigestible markers monitored by neutron activation analysis has been previously demonstrated in numerous species. In this study hafnium was used to mark corn and alfalfa rations as well as a combination ration made up of 90% alfalfa and 10% corn. The primary goal of the study was to evaluate the potential for use of rare earth stable markers in poultry digestion and to determine efficiency of meal marking, optimum exposure rates and determination limits for use in the design of future experimental protocols. Three groups of 10 hens each were fed a particular marked meal with fecal droppings monitored for 24 hours. The hens were sacrificed after a second dosed feeding and a delay of two or seven hours, and digesta was collected from each portion of the gastrointestinal tract. Fecal dry matter as well as digesta collected was then prepared for analysis and the elemental concentrations of hafnium were measured with instrumental neutron activation analysis (INAA). Element adsorption on alfalfa was far less efficient than on the corn ration, limiting the applicability of much of the alfalfa data to digestion studies. Passage rate curves were prepared for corn. The marker was found to primarily concentrate in the ileum at both sacrifice times. (author)

  12. Estimation of microbial respiration rates in groundwater by geochemical modeling constrained with stable isotopes

    Science.gov (United States)

    Murphy, E. M.; Schramke, J. A.

    1998-11-01

    Changes in geochemistry and stable isotopes along a well-established groundwater flow path were used to estimate in situ microbial respiration rates in the Middendorf aquifer in the southeastern United States. Respiration rates were determined for individual terminal electron acceptors including O 2, MnO 2, Fe 3+, and SO 42-. The extent of biotic reactions were constrained by the fractionation of stable isotopes of carbon and sulfur. Sulfur isotopes and the presence of sulfur-oxidizing microorganisms indicated that sulfate is produced through the oxidation of reduced sulfur species in the aquifer and not by the dissolution of gypsum, as previously reported. The respiration rates varied along the flow path as the groundwater transitioned between primarily oxic to anoxic conditions. Iron-reducing microorganisms were the largest contributors to the oxidation of organic matter along the portion of the groundwater flow path investigated in this study. The transition zone between oxic and anoxic groundwater contained a wide range of terminal electron acceptors and showed the greatest diversity and numbers of culturable microorganisms and the highest respiration rates. A comparison of respiration rates measured from core samples and pumped groundwater suggests that variability in respiration rates may often reflect the measurement scales, both in the sample volume and the time-frame over which the respiration measurement is averaged. Chemical heterogeneity may create a wide range of respiration rates when the scale of the observation is below the scale of the heterogeneity.

  13. A Test of Carbon and Oxygen Stable Isotope Ratio Process Models in Tree Rings.

    Science.gov (United States)

    Roden, J. S.; Farquhar, G. D.

    2008-12-01

    Stable isotopes ratios of carbon and oxygen in tree ring cellulose have been used to infer environmental change. Process-based models have been developed to clarify the potential of historic tree ring records for meaningful paleoclimatic reconstructions. However, isotopic variation can be influenced by multiple environmental factors making simplistic interpretations problematic. Recently, the dual isotope approach, where the variation in one stable isotope ratio (e.g. oxygen) is used to constrain the interpretation of variation in another (e.g. carbon), has been shown to have the potential to de-convolute isotopic analysis. However, this approach requires further testing to determine its applicability for paleo-reconstructions using tree-ring time series. We present a study where the information needed to parameterize mechanistic models for both carbon and oxygen stable isotope ratios were collected in controlled environment chambers for two species (Pinus radiata and Eucalyptus globulus). The seedlings were exposed to treatments designed to modify leaf temperature, transpiration rates, stomatal conductance and photosynthetic capacity. Both species were grown for over 100 days under two humidity regimes that differed by 20%. Stomatal conductance was significantly different between species and for seedlings under drought conditions but not between other treatments or humidity regimes. The treatments produced large differences in transpiration rate and photosynthesis. Treatments that effected photosynthetic rates but not stomatal conductance influenced carbon isotope discrimination more than those that influenced primarily conductance. The various treatments produced a range in oxygen isotope ratios of 7 ‰. Process models predicted greater oxygen isotope enrichment in tree ring cellulose than observed. The oxygen isotope ratios of bulk leaf water were reasonably well predicted by current steady-state models. However, the fractional difference between models that

  14. Stable pair invariants of surfaces and Seiberg-Witten invariants

    NARCIS (Netherlands)

    Kool, M.

    2016-01-01

    The moduli space of stable pairs on a local surface X = KS is in general non-compact. The action of C ∗ on the fibres of X induces an action on the moduli space and the stable pair invariants of X are defined by the virtual localization formula. We study the contribution to these invariants of

  15. Stable isotope methodology and its application to nutrition and gastroenterology

    International Nuclear Information System (INIS)

    Klein, P.D.; Hachey, D.L.; Wong, W.W.; Abrams, S.A.

    1993-01-01

    This report describes the activities of the Stable Isotope Laboratory in its function as a core resource facility for stable isotope applications in human nutrition research. Three aspects are covered: Training of visitors, assessment of new instrumentation, and development of new methodology. The research achievements of the laboratory are indicated in the publications that appeared during this period. (author). 23 refs

  16. Visual and olfactory enhancement of stable fly trapping.

    Science.gov (United States)

    Zhu, Junwei J; Zhang, Qing-He; Taylor, David B; Friesen, Kristina A

    2016-09-01

    Stable flies are considered to be one of the major blood-feeding pests in the US livestock industry, causing losses running into billions of dollars annually. Adult stable flies are highly attracted to Alsynite traps; however, Alsynite is becoming increasingly difficult to obtain and is expensive. Here, we report on the development of a less expensive and more efficacious trap based upon a white panel with the option to add visual and olfactory stimuli for enhanced stable fly trapping. White panel traps caught twice as many stable flies than Alsynite traps. Baiting the traps with synthetic manure volatiles increased catches 2-3-fold. Electroretinographic recordings of stable flies showed strong peaks of visual sensitivities occurring at 330-360 nm, 460-525 nm and 605-635 nm. A laboratory study indicated that young stable flies are more responsive to white, whereas gravid females prefer blue; in the field, white traps caught more stable flies than patterned or blue-black traps. Stable fly control can be enhanced by developing more efficient trapping systems with added visual and olfactory stimuli. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  17. Stability of Picard Bundle Over Moduli Space of Stable Vector ...

    Indian Academy of Sciences (India)

    Abstract. Answering a question of [BV] it is proved that the Picard bundle on the moduli space of stable vector bundles of rank two, on a Riemann surface of genus at least three, with fixed determinant of odd degree is stable.

  18. Stable isotope geochemistry. 3. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Hoefs, J.

    1987-01-01

    Stable Isotope Geochemistry is an authoritative book comprising theoretical and experimental principles; surveying important fractionation mechanisms affecting the most important elements; discussing the natural variations of geologically important reservoirs. This updated 3rd edition, with a completely rewritten and extended main part, contains two new chapters on stable isotope composition of mantle material and on changes of the ocean during the geological past. (orig.)

  19. Exploring Scintillometry in the Stable Atmospheric Surface Layer

    NARCIS (Netherlands)

    Hartogensis, O.K.

    2006-01-01

    The main objective of this thesis is to investigate observation methods of heat and momentum exchange and key variables that characterise turbulence in the atmospheric stable surface layer (SSL), a layer defined as the lower part of the stable boundary layer (SBL) where surface fluxes do not change

  20. DFT computations of the lattice constant, stable atomic structure and ...

    African Journals Online (AJOL)

    This paper presents the most stable atomic structure and lattice constant of Fullerenes (C60). FHI-aims DFT code was used to predict the stable structure and the computational lattice constant of C60. These were compared with known experimental structures and lattice constants of C60. The results obtained showed that ...

  1. Saturate hydraulic conductivity, water stable aggregates and soil ...

    African Journals Online (AJOL)

    Saturate hydraulic conductivity, water stable aggregates and soil organic matter in a sandy-loam soil in Ikwuano lga of Abia state. ... carbon content of the soil. . Keywords: Toposequence, Water stable aggregates, Saturated hydraulic conductivity, Organic carbon, Slope position. Agro-Science Vol. 4 (1) 2005: pp. 34-37.

  2. Optimization for getting stable plasma initiation in JT-60

    International Nuclear Information System (INIS)

    Yoshino, Ryuji; Neyatani, Yuzuru; Abe, T.

    1988-06-01

    This paper analyses the plasma current build-up just after the breakdown, and investigates the method for obtaining more stable plasma initiation with reduced Volt-second consumption. Control of the amount of particles contained in the wall is necessary for getting the optimum plasma density just after the breakdown, and is essential for obtaining the stable current build-up. (author)

  3. Improved Atmospheric Stable Boundary Layer Formulations for Navy Seasonal Forecasting

    Science.gov (United States)

    2012-09-30

    Long-term goals are to develop methods, descriptions and parameterizations that will alleviate long-standing problems in basically all large-scale numerical atmospheric models in dealing with statically stable and/or very stable conditions, and to implement these for Navy extended forecasting

  4. Fitted-Stable Finite Difference Method for Singularly Perturbed Two ...

    African Journals Online (AJOL)

    A fitted-stable central difference method is presented for solving singularly perturbed two point boundary value problems with the boundary layer at one end (left or right) of the interval. A fitting factor is introduced in second order stable central difference scheme (SCD Method) and its value is obtained using the theory of ...

  5. Stable isotope methods in biological and ecological studies of arthropods

    NARCIS (Netherlands)

    Hood-Nowotny, R.C.; Knols, B.G.J.

    2007-01-01

    This is an eclectic review and analysis of contemporary and promising stable isotope methodologies to study the biology and ecology of arthropods. It is augmented with literature from other disciplines, indicative of the potential for knowledge transfer. It is demonstrated that stable isotopes can

  6. Formulation of stable protein powders by supercritical fluid drying

    NARCIS (Netherlands)

    Jovanović, N.

    2007-01-01

    Protein pharmaceuticals are potent drugs for the treatment of several chronic and life-threatening diseases. However, the complex and sensitive nature of protein molecules requires special attention in the development of stable dosage forms. Developing stable aqueous protein formulations is often a

  7. Enhanced trapping of stable flies via olfactory and visual cues

    Science.gov (United States)

    Adult stable flies are highly attracted to the so-called Alsynite cylinder trap; however this trap is expensive. Here we report the development of a cheaper and better white panel trap with options of adding visual and olfactory stimuli for enhanced stable fly trapping. The white panel trap attracte...

  8. Wetting films of polar and nonpolar liquids.

    Science.gov (United States)

    Vazquez, Rosa; Nogueira, Rui; Busquets, Sandra; Mata, José Luís; Saramago, Benilde

    2005-04-15

    Disjoining pressure isotherms for water and n-octane films on glass obtained using a recently developed apparatus, based on the interferometric technique, are compared with other values reported in the literature. Our method, including a simple cleaning procedure, yields experimental results in excellent agreement both with other experimental results and with theoretical predictions. An error analysis was made which quantifies the uncertainty of our results and simultaneously allows the minimization of the errors.

  9. 1 SUPPLEMENTARY INFORMATION Nonpolar Solvation Dynamics ...

    Indian Academy of Sciences (India)

    IITP

    (i) radial distribution functions (g(r)) between [Bmim][PF6] RTIL atoms in order to verify that the proper solvent equilibration: Page 2. (ii) convergence of nonequilibrium and equilibrium solvation response functions: Page 3. (iii) g(r) between solute atoms and different carbon atoms of the side chain of the [Bmim]+ cation: Page ...

  10. Stable isotopes for improving human nutrition

    International Nuclear Information System (INIS)

    Uauy, Ricardo

    2001-01-01

    recent FAO review of nutrition programs in 19 Latin American countries found that over 20 percent of the population - approximately 83 million people out of an estimated 414 million in the study countries - receives some level of benefits in nutrition-related programs. The allocation of limited national and international assistance resources for these activities in the region is on the order of several billion dollars annually. Undoubtedly these programs are influencing child growth. Significant reductions in underweight and wasting have occurred; but stunting has been more resistant to change. In this setting providing food supplements may be beneficial for some while it may be detrimental for others. The definition of who should benefit from the programs and what is the right combination of nutrients/foods, education, and lifestyle interventions that is required to optimise nutrition and health at each stage of the life cycle is a truly complex problem. This demands the use of the best scientific tools to define who should benefit, what should done and measured as an outcome, how programs should be evaluated, when programs should be expanded, and when they should be stopped. Isotopic and nuclear techniques are tools, not solutions. This presentation will serve to demonstrate how isotopes can contribute to refining nutrition interventions and their impact on public health. Isotopic methods can shorten the time needed to evaluate impact, because they provide sensitive measurements of biological effects. They are faster than traditional methods such as anthropometry for detecting changes in growth and body composition. Micronutrient malnutrition, and especially the bioavailability of vitamins and minerals from traditional foods, are not well evaluated using routine biochemical methods. Radioisotopes have been used successfully in the past. But recent developments in stable isotope techniques offer unique advantages for the design and evaluation of programmes that address

  11. Sign change in the net force in sphere-plate and sphere-sphere systems immersed in nonpolar critical fluid due to the interplay between the critical Casimir and dispersion van der Waals forces.

    Science.gov (United States)

    Valchev, Galin; Dantchev, Daniel

    2017-08-01

    We study systems in which both long-ranged van der Waals and critical Casimir interactions are present. The latter arise as an effective force between bodies when immersed in a near-critical medium, say a nonpolar one-component fluid or a binary liquid mixture. They are due to the fact that the presence of the bodies modifies the order parameter profile of the medium between them as well as the spectrum of its allowed fluctuations. We study the interplay between these forces, as well as the total force (TF) between a spherical colloid particle and a thick planar slab and between two spherical colloid particles. We do that using general scaling arguments and mean-field-type calculations utilizing the Derjaguin and the surface integration approaches. They both are based on data of the forces between two parallel slabs separated at a distance L from each other, confining the fluctuating fluid medium characterized by its temperature T and chemical potential μ. The surfaces of the colloid particles and the slab are coated by thin layers exerting strong preference to the liquid phase of the fluid, or one of the components of the mixture, modeled by strong adsorbing local surface potentials, ensuring the so-called (+,+) boundary conditions. On the other hand, the core region of the slab and the particles influence the fluid by long-ranged competing dispersion potentials. We demonstrate that for a suitable set of colloids-fluid, slab-fluid, and fluid-fluid coupling parameters, the competition between the effects due to the coatings and the core regions of the objects involved result, when one changes T, μ, or L, in sign change of the Casimir force (CF) and the TF acting between the colloid and the slab, as well as between the colloids. This can be used for governing the behavior of objects, say colloidal particles, at small distances, say in colloid suspensions for preventing flocculation. It can also provide a strategy for solving problems with handling, feeding

  12. Sign change in the net force in sphere-plate and sphere-sphere systems immersed in nonpolar critical fluid due to the interplay between the critical Casimir and dispersion van der Waals forces

    Science.gov (United States)

    Valchev, Galin; Dantchev, Daniel

    2017-08-01

    We study systems in which both long-ranged van der Waals and critical Casimir interactions are present. The latter arise as an effective force between bodies when immersed in a near-critical medium, say a nonpolar one-component fluid or a binary liquid mixture. They are due to the fact that the presence of the bodies modifies the order parameter profile of the medium between them as well as the spectrum of its allowed fluctuations. We study the interplay between these forces, as well as the total force (TF) between a spherical colloid particle and a thick planar slab and between two spherical colloid particles. We do that using general scaling arguments and mean-field-type calculations utilizing the Derjaguin and the surface integration approaches. They both are based on data of the forces between two parallel slabs separated at a distance L from each other, confining the fluctuating fluid medium characterized by its temperature T and chemical potential μ . The surfaces of the colloid particles and the slab are coated by thin layers exerting strong preference to the liquid phase of the fluid, or one of the components of the mixture, modeled by strong adsorbing local surface potentials, ensuring the so-called (+,+) boundary conditions. On the other hand, the core region of the slab and the particles influence the fluid by long-ranged competing dispersion potentials. We demonstrate that for a suitable set of colloids-fluid, slab-fluid, and fluid-fluid coupling parameters, the competition between the effects due to the coatings and the core regions of the objects involved result, when one changes T , μ , or L , in sign change of the Casimir force (CF) and the TF acting between the colloid and the slab, as well as between the colloids. This can be used for governing the behavior of objects, say colloidal particles, at small distances, say in colloid suspensions for preventing flocculation. It can also provide a strategy for solving problems with handling, feeding

  13. The use of stable isotopes in drug metabolism studies.

    Science.gov (United States)

    Abramson, F P

    2001-06-01

    Although there is a long history of stable isotopes use in drug metabolism research, it is appropriate to evaluate them in pregnancy drug studies in which safety takes highest priority. It is well established through a number of human and animal experiments that stable isotopes themselves rarely generate additional toxicities beyond the molecules to which they are attached. For the analysis of stable isotopes involved in metabolism studies, mass spectrometry plays the predominant role. Several mass spectrometry-based techniques now exist that enable the selective quantitative detection of stable isotopes with better sensitivity and better retention of chromatographic resolution than do in-line radioactivity monitors for 14C. Even mass balance studies can be performed by using stable isotopes, a type of experiment that still predominantly uses radioisotopes. Some of the newest developments in the use of stable isotopes involve biopolymers, in which fully isotope-labeled species can be generated from cells grown in isotopically labeled growth media. Having shown safety, sensitivity, specificity, and versatility, stable isotopes should play an important role in drug metabolism studies in pregnancy.

  14. Small Tails Tell Tall Tales--Intra-Individual Variation in the Stable Isotope Values of Fish Fin.

    Science.gov (United States)

    Hayden, Brian; Soto, David X; Jardine, Tim D; Graham, Brittany S; Cunjak, Richard A; Romakkaniemi, Atso; Linnansaari, Tommi

    2015-01-01

    Fish fin is a widely used, non-lethal sample material in studies using stable isotopes to assess the ecology of fishes. However, fish fin is composed of two distinct tissues (ray and membrane) which may have different stable isotope values and are not homogeneously distributed within a fin. As such, estimates of the stable isotope values of a fish may vary according to the section of fin sampled. To assess the magnitude of this variation, we analysed carbon (δ13C), nitrogen (δ15N), hydrogen (δ2H) and oxygen (δ18O) stable isotopes of caudal fin from juvenile, riverine stages of Atlantic salmon (Salmo salar) and brown trout (Salmo trutta). Individual fins were sub-sectioned into tip, mid and base, of which a further subset were divided into ray and membrane. Isotope variation between fin sections, evident in all four elements, was primarily related to differences between ray and membrane. Base sections were13C depleted relative to tip (~1‰) with equivalent variation evident between ray and membrane. A similar trend was evident in δ2H, though the degree of variation was far greater (~10‰). Base and ray sections were 18O enriched (~2‰) relative to tip and membrane, respectively. Ray and membrane sections displayed longitudinal variation in 15N mirroring that of composite fin (~1‰), indicating that variation in15N values was likely related to ontogenetic variation. To account for the effects of intra-fin variability in stable isotope analyses we suggest that researchers sampling fish fin, in increasing priority, 1) also analyse muscle (or liver) tissue from a subsample of fish to calibrate their data, or 2) standardize sampling by selecting tissue only from the extreme tip of a fin, or 3) homogenize fins prior to analysis.

  15. A Model Describing Stable Coherent Synchrotron Radiation in Storage Rings

    International Nuclear Information System (INIS)

    Sannibale, F.

    2004-01-01

    We present a model describing high power stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The model includes distortion of bunch shape from the synchrotron radiation (SR), which enhances higher frequency coherent emission, and limits to stable emission due to an instability excited by the SR wakefield. It gives a quantitative explanation of several features of the recent observations of CSR at the BESSY II storage ring. We also use this model to optimize the performance of a source for stable CSR emission

  16. A model describing stable coherent synchrotron radiation in storage rings

    International Nuclear Information System (INIS)

    Sannibale, F.; Byrd, J.M.; Loftsdottir, A.; Venturini, M.; Abo-Bakr, M.; Feikes, J.; Holldack, K.; Kuske, P.; Wuestefeld, G.; Huebers, H.-W.; Warnock, R.

    2004-01-01

    We present a model describing high power stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The model includes distortion of bunch shape from the synchrotron radiation (SR), which enhances higher frequency coherent emission, and limits to stable emission due to an instability excited by the SR wakefield. It gives a quantitative explanation of several features of the recent observations of CSR at the BESSY II storage ring. We also use this model to optimize the performance of a source for stable CSR emission

  17. Stable black phosphorus quantum dots for alkali PH sensor

    Science.gov (United States)

    Guo, Weilan; Song, Haizeng; Yan, Shancheng

    2018-01-01

    Black phosphorus, as a new two-dimensional material has been widely used in sensors, photovoltaic devices, etc. However, thin layered black phosphorus chemically degrades rapidly under ambient and aqueous conditions, which hinders the application of it in the chemical sensors. In this work, stable black phosphorus quantum dots (BPQDs) in solution are successfully synthesized by functionalization with 4-nitrobenzene-diazonium (4-NBD). The stable BPQDs are investigated by TEM, AFM, Raman, and UV-absorption. As a potential application, the stable BPQDs are used as sensors in alkali solution, which exhibit outstanding performance. Our work paves the way towards a new application with BPQDs in solution.

  18. Use of stable isotopes in human nutrition in Senegal

    International Nuclear Information System (INIS)

    2016-01-01

    In Senegal, the Laboratory of Nutrition of the Department of Animal Biology of the Faculty of Science and Technology of UCAD has been using stable isotopic techniques for nearly twenty years. Stable isotopes were applied to different target populations to measure milk production, exclusive breastfeeding, body composition, micronutrient bioavailability and total energy expenditure.The application of stable isotopic techniques in nutrition has contributed to advocacy for exclusive breastfeeding for up to 6 months in Senegal. It enabled government decision-makers to obtain essential information on the quality of foods needed for optimal effect during pregnancy and for infant growth and the results were reflected in the national policy on micronutrient supplementation.

  19. High-Order Entropy Stable Formulations for Computational Fluid Dynamics

    Science.gov (United States)

    Carpenter, Mark H.; Fisher, Travis C.

    2013-01-01

    A systematic approach is presented for developing entropy stable (SS) formulations of any order for the Navier-Stokes equations. These SS formulations discretely conserve mass, momentum, energy and satisfy a mathematical entropy inequality. They are valid for smooth as well as discontinuous flows provided sufficient dissipation is added at shocks and discontinuities. Entropy stable formulations exist for all diagonal norm, summation-by-parts (SBP) operators, including all centered finite-difference operators, Legendre collocation finite-element operators, and certain finite-volume operators. Examples are presented using various entropy stable formulations that demonstrate the current state-of-the-art of these schemes.

  20. Stable emulsions in extraction systems containing zirconium and silicic acid

    International Nuclear Information System (INIS)

    Sinegribova, O.A.; Chizhevskaya, S.V.; Kotenko, A.A.

    1989-01-01

    The effect of zirconium nitrate compound nature and silicic acid on the rate of emulsions stratification in extraction systems depending on the components concentration, solution acidity, its past history, is studied. It is stated that stable multinuclear zirconium compounds have an influence on formation of stable emulsions in systems containing silicic acid. On the basis of results of chemical analysis and properties of interphase precipitates, being part of stable emulsion, suppositions on mechanism of interaction of zirconium nitrate compounds with silicic acid β-form are made

  1. What can Fe stable isotopes tell us about magmas?

    DEFF Research Database (Denmark)

    Stausberg, Niklas

    The majority of the Earth’s crust is formed by magmas, and understanding their production and differentiation is important to interpret the geologic rock record. A powerful tool to investigate magmatic processes is the distribution of the stable isotopes of the major redox-sensitive element...... the differentiation of magmas from the perspective of Fe stable isotopes, integrated with petrology, by studying igneous rocks and their constituent phases (minerals and glasses) from the Bushveld Complex, South Africa, Thingmuli, Iceland, Pantelleria, Italy, and the Bishop Tuff, USA. The findings are interpreted...... and for more quantitative model of the magmatic processes producing enigmatic stable isotope compositions of rhyolitic and granite magmas....

  2. Stable and Radiogenic Sr Isotopes in Barite - Clues on the Links Between Weathering, Climate and the C Cycle

    Science.gov (United States)

    Paytan, A.; Eisenhauer, A.; Wallmann, K. J. G.; Griffith, E. M.; Ridgwell, A.

    2017-12-01

    The radiogenic Sr-isotopic signature (87Sr/86Sr) of seawater fluctuates primarily in response to changes in the inputs of Sr from weathering and hydrothermal activity, which have distinct 87Sr/86Sr values. Changes in the isotopic ratio of the weathered terrain also contribute to observed changes in 87Sr/86Sr. The stable Sr-isotope ratios in seawater (mass dependent isotopic fractionation; δ88/86Sr) fluctuate primarily in response to the rate of calcium carbonate (CaCO3) accumulation at the seafloor. Together the radiogenic and stable Sr can constrain the coupling between weathering and sedimentation and shed light on the relation between weathering, CaCO3 deposition, the global carbon (C) cycle and climate. Reconstruction of the coupled stable and radiogenic Sr seawater curves over the past 35 Ma of Earth history indicates that the location and rate of CaCO3 burial in the ocean fluctuated considerably over the past 35 Ma. Between 35 to 18 Ma a reduction in neritic CaCO3 burial and increased burial in pelagic settings is observed. The trend was reversed between 20 and 3 Ma and finally over the last 3 million years a rapid change from neritic to pelagic burial is seen. The lack of continues increase of pelagic CaCO3 burial rates suggests that silicate weathering rates have not increased monotonically over the past 35 Ma implying strong feedbacks operating in the climate system - lower atmospheric pCO2 and cooling trends (which control chemical weathering as seen from carbonate deposition in the ocean) countered the effects of uplift (which controls physical weathering) - modulating weathering rates and preventing a runaway ice-house. In addition the data suggests considerable fluctuations in seawater Sr concentrations over time. These data demonstrate how using multiple isotope proxies can help constrain interpretations of the geological record.

  3. Enhancement of plasmid-mediated stable gene expression by ...

    African Journals Online (AJOL)

    WPRE) is a possible enhancer of gene expression in mammalian cells that promotes efficient export of unspliced (RNA) into the cytoplasm, as has been proved in transient transfection. In this study, WPRE was evaluated for enhancing stable ...

  4. Stable isotope labeling strategy based on coding theory

    International Nuclear Information System (INIS)

    Kasai, Takuma; Koshiba, Seizo; Yokoyama, Jun; Kigawa, Takanori

    2015-01-01

    We describe a strategy for stable isotope-aided protein nuclear magnetic resonance (NMR) analysis, called stable isotope encoding. The basic idea of this strategy is that amino-acid selective labeling can be considered as “encoding and decoding” processes, in which the information of amino acid type is encoded by the stable isotope labeling ratio of the corresponding residue and it is decoded by analyzing NMR spectra. According to the idea, the strategy can diminish the required number of labelled samples by increasing information content per sample, enabling discrimination of 19 kinds of non-proline amino acids with only three labeled samples. The idea also enables this strategy to combine with information technologies, such as error detection by check digit, to improve the robustness of analyses with low quality data. Stable isotope encoding will facilitate NMR analyses of proteins under non-ideal conditions, such as those in large complex systems, with low-solubility, and in living cells

  5. Estimation of Time Varying Autoregressive Symmetric Alpha Stable

    Data.gov (United States)

    National Aeronautics and Space Administration — In this work, we present a novel method for modeling time-varying autoregressive impulsive signals driven by symmetric alpha stable distributions. The proposed...

  6. Quantification of stable isotope label in metabolites via mass spectrometry.

    Science.gov (United States)

    Huege, Jan; Goetze, Jan; Dethloff, Frederik; Junker, Bjoern; Kopka, Joachim

    2014-01-01

    Isotope labelling experiments with stable or radioactive isotopes have long been an integral part of biological and medical research. Labelling experiments led to the discovery of new metabolic pathways and made it possible to calculate the fluxes responsible for a metabolic phenotype, i.e., the qualitative and quantitative composition of metabolites in a biological system. Prerequisite for efficient isotope labelling experiments is a reliable and precise method to analyze the redistribution of isotope label in a metabolic network. Here we describe the use of the CORRECTOR program, which utilizes matrix calculations to correct mass spectral data from stable isotope labelling experiments for the distorting effect of naturally occurring stable isotopes (NOIs). CORRECTOR facilitates and speeds up the routine quantification of experimentally introduced isotope label from multiple mass spectral readouts, which are generated by routine metabolite profiling when combined with stable isotope labelling experiments.

  7. On the classification of complex vector bundles of stable rank

    Indian Academy of Sciences (India)

    , the tuples of cohomology classes on a compact, complex manifold, corresponding to the Chern classes of a complex vector bundle of stable rank. This classification becomes more effective on generalized flag manifolds, where the Lie ...

  8. Comparing Fr\\'echet and positive stable laws

    OpenAIRE

    Simon, Thomas

    2013-01-01

    Let ${\\bf L}$ be the unit exponential random variable and ${\\bf Z}_\\alpha$ the standard positive $\\alpha$-stable random variable. We prove that $\\{(1-\\alpha) \\alpha^{\\gamma_\\alpha} {\\bf Z}_\\alpha^{-\\gamma_\\alpha}, 0< \\alpha

  9. Thermally-Stable High Strain Deployable Structures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is for the development of a thermally-stable composite made of carbon fibers and elastomeric resin. This combination of materials will allow...

  10. Using stable isotopes to determine seabird trophic relationships

    Science.gov (United States)

    Hobson, Keith A.; Piatt, John F.; Pitocchelli, Jay

    1994-01-01

    1. The stable isotopes of nitrogen (δ15N) and carbon (δ13C) were analysed in 22 species of marine birds from coastal waters of the northeast Pacific Ocean. Analyses confirm that stable nitrogen isotopes can predict seabird trophic positions.2. Based on δ15N analyses, seabird trophic-level inferences generally agree with those of conventional dietary studies, but suggest that lower trophic-level organisms are more important to several seabirds than was recognized previously.3. Stable-carbon isotope analysis may be a good indicator of inshore vs. offshore feeding preference.4. In general, stable-isotope analysis to determine trophic level offers many advantages over conventional dietary approaches since trophic inferences are based on time-integrated estimates of assimilated and not just ingested foods, and isotopic abundance represents a continuous variable that is amenable to statistical analysis.

  11. STABLE ISOTOPES IN ECOLOGICAL STUDIES: NEW DEVELOPMENTS IN MIXING MODELS

    Science.gov (United States)

    Stable isotopes are increasingly being used as tracers in ecological studies. One application uses isotopic ratios to quantify the proportional contributions of multiple sources to a mixture. Examples include food sources for animals, water sources for plants, pollution sources...

  12. Stable isotope views on ecosystem function: challenging or challenged?

    Science.gov (United States)

    Resco, Víctor; Querejeta, José I.; Ogle, Kiona; Voltas, Jordi; Sebastià, Maria-Teresa; Serrano-Ortiz, Penélope; Linares, Juan C.; Moreno-Gutiérrez, Cristina; Herrero, Asier; Carreira, José A.; Torres-Cañabate, Patricia; Valladares, Fernando

    2010-01-01

    Stable isotopes and their potential for detecting various and complex ecosystem processes are attracting an increasing number of scientists. Progress is challenging, particularly under global change scenarios, but some established views have been challenged. The IX meeting of the Spanish Association of Terrestrial Ecology (AAET, Úbeda, 18–22 October 2009) hosted a symposium on the ecology of stable isotopes where the linear mixing model approach of partitioning sinks and sources of carbon and water fluxes within an ecosystem was challenged, and new applications of stable isotopes for the study of plant interactions were evaluated. Discussion was also centred on the need for networks that monitor ecological processes using stable isotopes and key ideas for fostering future research with isotopes. PMID:20015858

  13. US ITASE Stable Isotope Data, Antarctica, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes stable isotope measurements from snow pits, firn, and ice cores collected by the the US component of the International Trans-Antarctic...

  14. A stable isotopic study of the diet of Potamonautes sidneyi ...

    African Journals Online (AJOL)

    Natal, South Africa. Recent flood events in the iSimangaliso Wetland Park have allowed a substantial range expansion of this species, including previously hypersaline and desiccated areas. A stable isotope study was conducted to examine ...

  15. Stable isotopes: essential tools in biological and medical research

    Energy Technology Data Exchange (ETDEWEB)

    Klein, P. D.; Hachey, D. L.; Kreek, M. J.; Schoeller, D. A.

    1977-01-01

    Recent developments in the use of the stable isotopes, /sup 13/C, /sup 15/N, /sup 17/O, and /sup 18/O, as tracers in research studies in the fields of biology, medicine, pharmacology, and agriculture are briefly reviewed. (CH)

  16. [Fractionation of hydrogen stable isotopes in the human body].

    Science.gov (United States)

    Siniak, Iu E; Grigor'ev, A I; Skuratov, V M; Ivanova, S M; Pokrovskiĭ, B G

    2006-01-01

    Fractionation of hydrogen stable isotopes was studied in 9 human subjects in a chamber with normal air pressure imitating a space cabin. Mass-spectrometry of isotopes in blood, urine, saliva, and potable water evidenced increases in the contents of heavy H isotope (deuterium) in the body liquids as compared with water. These results support one of the theories according to which the human organism eliminates heavy stable isotopes of biogenous chemical elements.

  17. Stable isotopes in pharmacology studies: present and future

    International Nuclear Information System (INIS)

    Browne, T.R.

    1986-01-01

    Stable-isotope techniques offer advantages over older methods in safety, sensitivity, specificity, and reduction in numbers of subjects required and analytic determinations for some types of pharmacology studies. In addition to their use as internal standards in gas chromatography-mass spectrometry analytic methods, stable isotopes have been successfully employed in studies of absorption, bioavailability, distribution, biotransformation, excretion, metabolite identification, time-dependent and dose-dependent pharmacokinetic changes, drug interactions, pharmacologic changes during pregnancy, mutagenicity, and teratogenicity. 32 references

  18. Elastic Stable Intramedullary Nailing for Treatment of Pediatric Tibial Fractures

    OpenAIRE

    Sandeep Gurung; Dipendra KC; Roshni Khatri

    2016-01-01

    Introduction: Tibia fractures in the skeletally immature patient can usually be treated with above knee cast or patellar tendon bearing cast. The purpose of our study was to evaluate epidemiology and outcome of Elastic stable intramedullary nailing fixation of pediatric tibial shaft fractures treated at our institution. Methods: Over a period of one year, fifty pediatric patients of tibial shaft fractures, with average age of 9.68 yr (SD=2.37), were treated with elastic stable intramedul...

  19. The stable stiffness triangle - drained sand during deformation cycles

    DEFF Research Database (Denmark)

    Sabaliauskas, Tomas; Ibsen, Lars Bo

    2017-01-01

    Cyclic, drained sand stiffness was observed using the Danish triaxial appa- ratus. New, deformation dependant soil property (the stable stiffness triangle) was detected. Using the the stable stiffness triangle, secant stiffness of drained sand was plausible to predict (and control) even during ir...... findings can find application in off-shore, seismic and other engi- neering practice, or inspire new branches of research and modelling wherever dynamic, cyclic or transient loaded sand is encountered....

  20. Risk following hospitalization in stable chronic systolic heart failure

    DEFF Research Database (Denmark)

    Abrahamsson, Putte; Swedberg, Karl; Borer, Jeffrey S

    2013-01-01

    We explored the impact of being hospitalized due to worsening heart failure (WHF) or a myocardial infarction (MI) on subsequent mortality in a large contemporary data set of patients with stable chronic systolic heart failure (HF).......We explored the impact of being hospitalized due to worsening heart failure (WHF) or a myocardial infarction (MI) on subsequent mortality in a large contemporary data set of patients with stable chronic systolic heart failure (HF)....

  1. A parallel approach to the stable marriage problem

    DEFF Research Database (Denmark)

    Larsen, Jesper

    1997-01-01

    This paper describes two parallel algorithms for the stable marriage problem implemented on a MIMD parallel computer. The algorithms are tested against sequential algorithms on randomly generated and worst-case instances. The results clearly show that the combination fo a very simple problem...... and a commercial MIMD system results in parallel algorithms which are not competitive with sequential algorithms wrt. practical performance. 1 Introduction In 1962 the Stable Marriage Problem was....

  2. Wideband quin-stable energy harvesting via combined nonlinearity

    Directory of Open Access Journals (Sweden)

    Chen Wang

    2017-04-01

    Full Text Available In this work, we propose a wideband quintuple-well potential piezoelectric-based vibration energy harvester using a combined nonlinearity: the magnetic nonlinearity induced by magnetic force and the piecewise-linearity produced by mechanical impact. With extra stable states compared to other multi-stable harvesters, the quin-stable harvester can distribute its potential energy more uniformly, which provides shallower potential wells and results in lower excitation threshold for interwell motion. The mathematical model of this quin-stable harvester is derived and its equivalent piecewise-nonlinear restoring force is measured in the experiment and identified as piecewise polynomials. Numerical simulations and experimental verifications are performed in different levels of sinusoid excitation ranging from 1 to 25 Hz. The results demonstrate that, with lower potential barriers compared with tri-stable counterpart, the quin-stable arrangement can escape potential wells more easily for doing high-energy interwell motion over a wider band of frequencies. Moreover, by utilizing the mechanical stoppers, this harvester can produce significant output voltage under small tip deflections, which results in a high power density and is especially suitable for a compact MEMS approach.

  3. Medieval horse stable; the results of multi proxy interdisciplinary research.

    Science.gov (United States)

    Dejmal, Miroslav; Lisá, Lenka; Fišáková Nývltová, Miriam; Bajer, Aleš; Petr, Libor; Kočár, Petr; Kočárová, Romana; Nejman, Ladislav; Rybníček, Michal; Sůvová, Zdenka; Culp, Randy; Vavrčík, Hanuš

    2014-01-01

    A multi proxy approach was applied in the reconstruction of the architecture of Medieval horse stable architecture, the maintenance practices associated with that structure as well as horse alimentation at the beginning of 13th century in Central Europe. Finally, an interpretation of the local vegetation structure along Morava River, Czech Republic is presented. The investigated stable experienced two construction phases. The infill was well preserved and its composition reflects maintenance practices. The uppermost part of the infill was composed of fresh stabling, which accumulated within a few months at the end of summer. Horses from different backgrounds were kept in the stable and this is reflected in the results of isotope analyses. Horses were fed meadow grasses as well as woody vegetation, millet, oat, and less commonly hemp, wheat and rye. Three possible explanations of stable usage are suggested. The stable was probably used on a temporary basis for horses of workers employed at the castle, courier horses and horses used in battle.

  4. Medieval Horse Stable; The Results of Multi Proxy Interdisciplinary Research

    Science.gov (United States)

    Dejmal, Miroslav; Lisá, Lenka; Fišáková Nývltová, Miriam; Bajer, Aleš; Petr, Libor; Kočár, Petr; Kočárová, Romana; Nejman, Ladislav; Rybníček, Michal; Sůvová, Zdenka; Culp, Randy; Vavrčík, Hanuš

    2014-01-01

    A multi proxy approach was applied in the reconstruction of the architecture of Medieval horse stable architecture, the maintenance practices associated with that structure as well as horse alimentation at the beginning of 13th century in Central Europe. Finally, an interpretation of the local vegetation structure along Morava River, Czech Republic is presented. The investigated stable experienced two construction phases. The infill was well preserved and its composition reflects maintenance practices. The uppermost part of the infill was composed of fresh stabling, which accumulated within a few months at the end of summer. Horses from different backgrounds were kept in the stable and this is reflected in the results of isotope analyses. Horses were fed meadow grasses as well as woody vegetation, millet, oat, and less commonly hemp, wheat and rye. Three possible explanations of stable usage are suggested. The stable was probably used on a temporary basis for horses of workers employed at the castle, courier horses and horses used in battle. PMID:24670874

  5. Stable Fly, Stomoxys calcitrans (L.), Dispersal and Governing Factors.

    Science.gov (United States)

    Showler, Allan T; Osbrink, Weste L A

    2015-01-01

    Although the movement of stable fly, Stomoxys calcitrans (L.), has been studied, its extent and significance has been uncertain. On a local scale (fly movement occurs between host animals and resting sites to feed and mate, mainly at on-farm locations where herbivorous livestock regularly congregate. Small numbers emigrate from livestock congregation sites in search of other hosts and oviposition substrate, mostly within stable flies are active year-round in warm latitudes, cold winters in temperate areas result in substantial population and activity declines, limiting movement of any sort to warmer seasons. Long-distance dispersal (>13 km) is mainly wind-driven by weather fronts that carry stable flies from inland farm areas for up to 225 km to beaches of northwestern Florida and Lake Superior. Stable flies can reproduce for a short time each year in washed-up sea grass, but the beaches are not conducive to establishment. Such movement is passive and does not appear to be advantageous to stable fly's survival. On a regional scale, stable flies exhibit little genetic differentiation, and on the global scale, while there might be more than one "lineage", the species is nevertheless considered to be panmictic. Population expansion across much of the globe likely occurred from the late Pleistocene to the early Holocene in association with the spread of domesticated nomad livestock and particularly with more sedentary, penned livestock.

  6. Metal stable isotope signatures as tracers in environmental geochemistry.

    Science.gov (United States)

    Wiederhold, Jan G

    2015-03-03

    The biogeochemical cycling of metals in natural systems is often accompanied by stable isotope fractionation which can now be measured due to recent analytical advances. In consequence, a new research field has emerged over the last two decades, complementing the traditional stable isotope systems (H, C, O, N, S) with many more elements across the periodic table (Li, B, Mg, Si, Cl, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, Ge, Se, Br, Sr, Mo, Ag, Cd, Sn, Sb, Te, Ba, W, Pt, Hg, Tl, U) which are being explored and potentially applicable as novel geochemical tracers. This review presents the application of metal stable isotopes as source and process tracers in environmental studies, in particular by using mixing and Rayleigh model approaches. The most important concepts of mass-dependent and mass-independent metal stable isotope fractionation are introduced, and the extent of natural isotopic variations for different elements is compared. A particular focus lies on a discussion of processes (redox transformations, complexation, sorption, precipitation, dissolution, evaporation, diffusion, biological cycling) which are able to induce metal stable isotope fractionation in environmental systems. Additionally, the usefulness and limitations of metal stable isotope signatures as tracers in environmental geochemistry are discussed and future perspectives presented.

  7. Medieval horse stable; the results of multi proxy interdisciplinary research.

    Directory of Open Access Journals (Sweden)

    Miroslav Dejmal

    Full Text Available A multi proxy approach was applied in the reconstruction of the architecture of Medieval horse stable architecture, the maintenance practices associated with that structure as well as horse alimentation at the beginning of 13th century in Central Europe. Finally, an interpretation of the local vegetation structure along Morava River, Czech Republic is presented. The investigated stable experienced two construction phases. The infill was well preserved and its composition reflects maintenance practices. The uppermost part of the infill was composed of fresh stabling, which accumulated within a few months at the end of summer. Horses from different backgrounds were kept in the stable and this is reflected in the results of isotope analyses. Horses were fed meadow grasses as well as woody vegetation, millet, oat, and less commonly hemp, wheat and rye. Three possible explanations of stable usage are suggested. The stable was probably used on a temporary basis for horses of workers employed at the castle, courier horses and horses used in battle.

  8. Stable and sporadic symbiotic communities of coral and algal holobionts

    Science.gov (United States)

    Hester, Eric R; Barott, Katie L; Nulton, Jim; Vermeij, Mark JA; Rohwer, Forest L

    2016-01-01

    Coral and algal holobionts are assemblages of macroorganisms and microorganisms, including viruses, Bacteria, Archaea, protists and fungi. Despite a decade of research, it remains unclear whether these associations are spatial–temporally stable or species-specific. We hypothesized that conflicting interpretations of the data arise from high noise associated with sporadic microbial symbionts overwhelming signatures of stable holobiont members. To test this hypothesis, the bacterial communities associated with three coral species (Acropora rosaria, Acropora hyacinthus and Porites lutea) and two algal guilds (crustose coralline algae and turf algae) from 131 samples were analyzed using a novel statistical approach termed the Abundance-Ubiquity (AU) test. The AU test determines whether a given bacterial species would be present given additional sampling effort (that is, stable) versus those species that are sporadically associated with a sample. Using the AU test, we show that coral and algal holobionts have a high-diversity group of stable symbionts. Stable symbionts are not exclusive to one species of coral or algae. No single bacterial species was ubiquitously associated with one host, showing that there is not strict heredity of the microbiome. In addition to the stable symbionts, there was a low-diversity community of sporadic symbionts whose abundance varied widely across individual holobionts of the same species. Identification of these two symbiont communities supports the holobiont model and calls into question the hologenome theory of evolution. PMID:26555246

  9. Encapsulation of Metallic Na in an Electrically Conductive Host with Porous Channels as a Highly Stable Na Metal Anode.

    Science.gov (United States)

    Luo, Wei; Zhang, Ying; Xu, Shaomao; Dai, Jiaqi; Hitz, Emily; Li, Yiju; Yang, Chunpeng; Chen, Chaoji; Liu, Boyang; Hu, Liangbing

    2017-06-14

    Room-temperature Na ion batteries (NIBs) have attracted great attention because of the widely available, abundant sodium resources and potentially low cost. Currently, the challenge of the NIB development is due primarily to the lack of a high-performance anode, while the Na metal anode holds great promise considering its highest specific capacity of 1165 mA h/g and lowest anodic potential. However, an uneven deposit, relatively infinite volume change, and dendritic growth upon plating/stripping cycles cause a low Coulombic efficiency, poor cycling performance, and severe safety concerns. Here, a stable Na carbonized wood (Na-wood) composite anode was fabricated via a rapid melt infusion (about 5 s) into channels of carbonized wood by capillary action. The channels function as a high-surface-area, conductive, mechanically stable skeleton, which lowers the effective current density, ensures a uniform Na nucleation, and restricts the volume change over cycles. As a result, the Na-wood composite anode exhibited flat plating/stripping profiles with smaller overpotentials and stable cycling performance over 500 h at 1.0 mA/cm 2 in a common carbonate electrolyte system. In sharp comparison, the planar Na metal electrode showed a much shorter cycle life of 100 h under the same test conditions.

  10. Multi-stable perception balances stability and sensitivity

    Directory of Open Access Journals (Sweden)

    Alexander ePastukhov

    2013-03-01

    Full Text Available We report that multi-stable perception operates in a consistent, dynamical regime, balancing the conflicting goals of stability and sensitivity. When a multi-stable visual display is viewed continuously, its phenomenal appearance reverses spontaneously at irregular intervals. We characterized the perceptual dynamics of individual observers in terms of four statistical measures: the distribution of dominance times (mean and variance and the novel, subtle dependence on prior history (correlation and time-constant.The dynamics of multi-stable perception is known to reflect several stabilizing and destabilizing factors. Phenomenologically, its main aspects are captured by a simplistic computational model with competition, adaptation, and noise. We identified small parameter volumes (~3% of the possible volume in which the model reproduced both dominance distribution and history-dependence of each observer. For 21 of 24 data sets, the identified volumes clustered tightly (~15% of the possible volume, revealing a consistent `operating regime' of multi-stable perception. The `operating regime' turned out to be marginally stable or, equivalently, near the brink of an oscillatory instability. The chance probability of the observed clustering was <0.02.To understand the functional significance of this empirical `operating regime', we compared it to the theoretical `sweet spot' of the model. We computed this `sweet spot' as the intersection of the parameter volumes in which the model produced stable perceptual outcomes and in which it was sensitive to input modulations. Remarkably, the empirical `operating regime' proved to be largely coextensive with the theoretical `sweet spot'. This demonstrated that perceptual dynamics was not merely consistent but also functionally optimized (in that it balances stability with sensitivity. Our results imply that multi-stable perception is not a laboratory curiosity, but reflects a functional optimization of perceptual

  11. Introducing fecal stable isotope analysis in primate weaning studies.

    Science.gov (United States)

    Reitsema, Laurie J

    2012-10-01

    This research investigates the potential of a new, noninvasive method for determining age of weaning among primates using stable carbon and nitrogen isotope ratios in feces. Analysis of stable isotope ratios in body tissues is a well-established method in archeology and ecology for reconstructing diet. This is the first study to investigate weaning in primates using fecal stable isotope ratios. Diets of a single François' langur (Trachypithecus francoisi) mother-infant pair at the Toledo Zoo are reconstructed using this technique to track changes in infant suckling behavior over the weaning period. Stable isotope ratios in feces are sampled instead of more traditional samples such as bone or hair to enable daily, noninvasive snapshots of weaning status. Isotopic assessments of weaning status are compared to visual assessments to identify any discordance between the two. Three measurements documented the transition from breast milk to solid foods: stable carbon isotope ratios (δ(13)C), stable nitrogen isotope ratios (δ(15)N), and nitrogen content of feces (%N). It appears that solid foods were introduced at approximately 2 months of infant age, but that nursing continued into the 12th month, when sample collection ceased. Stable isotope data exposed a much longer weaning period than what was expected based on previously published data for captive langurs, and clarified visual estimates of weaning status. This reflects the method's sensitivity to suckling at night and ability to distinguish actual nursing from comfort nursing. After testing this method with zoo animals, it can readily be applied among wild populations. An isotopic approach to weaning provides a new, accurate, and biologically meaningful assessment of interbirth intervals, and facilitates a better understanding of mother-infant interactions. Both of these outcomes are critical for developing successful conservation strategies for captive and wild primates. © 2012 Wiley Periodicals, Inc.

  12. Water-stable fac-{TcO₃}⁺ complexes - a new field of technetium chemistry.

    Science.gov (United States)

    Braband, Henrik

    2011-01-01

    The development of technetium chemistry has been lagging behind that of its heavier congener rhenium, primarily because the inherent radioactivity of all Tc isotopes has limited the number of laboratories that can study the chemistry of this fascinating element. Although technetium is an artificial element, it is not rare. Significant amounts of the isotope (99)Tc are produced every day as a fission byproduct in nuclear power plants. Therefore, a fundamental understanding of the chemistry of (99)Tc is essential to avoid its release into the environment. In this article the chemistry of technetium at its highest oxidation state (+VII) is reviewed with a special focus on recent developments which make water-stable complexes of the general type [TcO(3)(tacn-R)](+) (tacn-R = 1,4,7-triazacyclononane or derivatives) accessible. Complexes containing the fac-{TcO(3)}(+) core display a unique reactivity. In analogy to [OsO(4)] and [RuO(4)], complexes containing the fac-{TcO(3)}(+) core undergo with alkenes metal-mediated, vicinal cis-dihydroxylation reactions (alkene-glycol interconversion) in water via a (3+2)-cycloaddition reaction. Therefore, water-stable fac-{(99m)TcO(3)}(+) complexes pave the way for a new labeling strategy for radiopharmaceutical applications, based on (3+2)-cycloaddition reactions. This new concept for the labeling of biomolecules with small [(99m)TcO(3)(tacn-R)](+)-type complexes by way of a (3+2)-cycloaddition with alkenes is discussed in detail. The herein reported developments in high-valent technetium chemistry create a new field of research with this artificial element. This demonstrates the potential of fundamental research to provide new impetus of innovation for the development of new methods for radiopharmaceutical applications.

  13. Copper in soil fractions and runoff in a vineyard catchment: Insights from copper stable isotopes.

    Science.gov (United States)

    Babcsányi, Izabella; Chabaux, François; Granet, Mathieu; Meite, Fatima; Payraudeau, Sylvain; Duplay, Joëlle; Imfeld, Gwenaël

    2016-07-01

    Understanding the fate of copper (Cu) fungicides in vineyard soils and catchments is a prerequisite to limit the off-site impact of Cu. Using Cu stable isotopes, Cu retention in soils and runoff transport was investigated in relation to the use of Cu fungicides and the hydrological conditions in a vineyard catchment (Rouffach, Haut-Rhin, France; mean slope: 15%). The δ(65)Cu values of the bulk vineyard soil varied moderately through the depth of the soil profiles (-0.12 to 0.24‰±0.08‰). The values were in the range of those of the fungicides (-0.21 to 0.11‰) and included the geogenic δ(65)Cu value of the untreated soil (0.08‰). However, δ(65)Cu values significantly differed between particle-size soil fractions (-0.37±0.10‰ in fine clays and 0.23±0.07‰ in silt). Together with the soil mineralogy, the results suggested Cu isotope fractionation primarily associated with the clay and fine clay fractions that include both SOM and mineral phases. The vegetation did not affect the Cu isotope patterns in the vineyard soils. Cu export by runoff from the catchment accounted for 1% of the applied Cu mass from 11th May to 20(th) July 2011, covering most of the Cu use period. 84% of the exported Cu mass was Cu bound to suspended particulate matter (SPM). The runoff displayed δ(65)Cu values from 0.52 to 1.35‰ in the dissolved phase (stable isotopes may allow identifying the Cu distribution in the soil fractions and their contribution to Cu export in runoff from Cu-contaminated catchments. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Dynamics and control of twisting bi-stable structures

    Science.gov (United States)

    Arrieta, Andres F.; van Gemmeren, Valentin; Anderson, Aaron J.; Weaver, Paul M.

    2018-02-01

    Compliance-based morphing structures have the potential to offer large shape adaptation, high stiffness and low weight, while reducing complexity, friction, and scalability problems of mechanism based systems. A promising class of structure that enables these characteristics are multi-stable structures given their ability to exhibit large deflections and rotations without the expensive need for continuous actuation, with the latter only required intermittently. Furthermore, multi-stable structures exhibit inherently fast response due to the snap-through instability governing changes between stable states, enabling rapid configuration switching between the discrete number of programmed shapes of the structure. In this paper, the design and utilisation of the inherent nonlinear dynamics of bi-stable twisting I-beam structures for actuation with low strain piezoelectric materials is presented. The I-beam structure consists of three compliant components assembled into a monolithic single element, free of moving parts, and showing large deflections between two stable states. Finite element analysis is utilised to uncover the distribution of strain across the width of the flange, guiding the choice of positioning for piezoelectric actuators. In addition, the actuation authority is maximised by calculating the generalised coupling coefficient for different positions of the piezoelectric actuators. The results obtained are employed to tailor and test I-beam designs exhibiting desired large deflection between stable states, while still enabling the activation of snap-through with the low strain piezoelectric actuators. To this end, the dynamic response of the I-beams to piezoelectric excitation is investigated, revealing that resonant excitations are insufficient to dynamically trigger snap-through. A novel bang-bang control strategy, which exploits the nonlinear dynamics of the structure successfully triggers both single and constant snap-through between the stable states

  15. Book review: Use of Stable Iodine in Nuclear Emergencies

    Directory of Open Access Journals (Sweden)

    Iraj Nabipour

    2011-11-01

    Full Text Available Following a radiological or nuclear event, radioactive iodine may be get into the body through respiratory or gastrointestinal systems. In the contaminated cases with radioactive iodine, the radioactive iodine absorbed by the thyroid can injure the gland. Because of the carcinogenic effects of its radiation, there is a significant public health risk in the event of exposure to radioactive iodine. On other hand, due to stable (non-radioactive iodine acts to block radioactive iodine from being taken into the thyroid gland, it can help protect this gland from injury and following side effects. In this query, potassium iodide (also called KI is a salt of stable iodine in a medicine form which is recommended to use sine many years ago. With effective planning and the use of stable iodine prophylaxis, accompanied with other protective implementations, this risk is mostly avoidable. This book contains information such as iodine and physiology kinetic , exposure risk to radioactive iodine, how to use stable iodine in this events , complications attributed to stable(non-radioactive iodine and also at last chapter the final recommendation published by WHO is included.

  16. Clinical phase I/II trial to investigate neoadjuvant intensity-modulated short term radiation therapy (5 × 5 gy) and intraoperative radiation therapy (15 gy) in patients with primarily resectable pancreatic cancer - NEOPANC

    International Nuclear Information System (INIS)

    Roeder, Falk; Debus, Juergen; Huber, Peter E; Werner, Jens; Timke, Carmen; Saleh-Ebrahimi, Ladan; Schneider, Lutz; Hackert, Thilo; Hartwig, Werner; Kopp-Schneider, Annette; Hensley, Frank W; Buechler, Markus W

    2012-01-01

    The current standard treatment, at least in Europe, for patients with primarily resectable tumors, consists of surgery followed by adjuvant chemotherapy. But even in this prognostic favourable group, long term survival is disappointing because of high local and distant failure rates. Postoperative chemoradiation has shown improved local control and overalls survival compared to surgery alone but the value of additional radiation has been questioned in case of adjuvant chemotherapy. However, there remains a strong rationale for the addition of radiation therapy considering the high rates of microscopically incomplete resections after surgery. As postoperative administration of radiation therapy has some general disadvantages, neoadjuvant and intraoperative approaches theoretically offer benefits in terms of dose escalation, reduction of toxicity and patients comfort especially if hypofractionated regimens with highly conformal techniques like intensity-modulated radiation therapy are considered. The NEOPANC trial is a prospective, one armed, single center phase I/II study investigating a combination of neoadjuvant short course intensity-modulated radiation therapy (5 × 5 Gy) in combination with surgery and intraoperative radiation therapy (15 Gy), followed by adjuvant chemotherapy according to the german treatment guidelines, in patients with primarily resectable pancreatic cancer. The aim of accrual is 46 patients. The primary objectives of the NEOPANC trial are to evaluate the general feasibility of this approach and the local recurrence rate after one year. Secondary endpoints are progression-free survival, overall survival, acute and late toxicity, postoperative morbidity and mortality and quality of life. http://www.clinicaltrials.gov/ct2/show/NCT01372735

  17. Stable Isotope Ratios as Biomarkers of Diet for Health Research.

    Science.gov (United States)

    O'Brien, Diane M

    2015-01-01

    Diet is a leading modifiable risk factor for chronic disease, but it remains difficult to measure accurately due to the error and bias inherent in self-reported methods of diet assessment. Consequently, there is a pressing need for more objective biomarkers of diet for use in health research. The stable isotope ratios of light elements are a promising set of candidate biomarkers because they vary naturally and reproducibly among foods, and those variations are captured in molecules and tissues with high fidelity. Recent studies have identified valid isotopic measures of short- and long-term sugar intake, meat intake, and fish intake in specific populations. These studies provide a strong foundation for validating stable isotopic biomarkers in the general US population. Approaches to improve specificity for specific foods are needed; for example, by modeling intake using multiple stable isotope ratios or by isolating and measuring specific molecules linked to foods of interest.

  18. Design of partially optically stable reflector systems and prisms

    Science.gov (United States)

    Tsai, Chuang-Yu

    2010-09-01

    The characteristics and design method of the total optically stable (TOS) reflector systems/prisms were introduced in an early paper (Tsai and Lin in Appl. Opt. 47:4158-4163, 2008), where only two types of TOS reflector system exist, namely preservation or retroreflection. In this paper, we introduce the partially optically stable (POS) reflector system, which is only optically stable about a specific directional vector; nevertheless, the exiting light ray is not restricted to preservation or retroreflection. The proposed paper also presents an analytic method for the design of POS reflector systems comprised of multiple reflectors. Furthermore, it is shown that a POS prism can be obtained by adding two refracting flat boundary surfaces with specific conditions at the entrance and exit positions of the light ray in an optical system with multiple reflectors.

  19. Picosecond pulse generated supercontinuum as a stable seed for OPCPA.

    Science.gov (United States)

    Indra, Lukáš; Batysta, František; Hříbek, Petr; Novák, Jakub; Hubka, Zbyněk; Green, Jonathan T; Antipenkov, Roman; Boge, Robert; Naylon, Jack A; Bakule, Pavel; Rus, Bedřich

    2017-02-15

    We present a stable supercontinuum (SC) generated in a bulk YAG crystal, pumped by 3 ps chirped pulses at 1030 nm. The SC is generated in a loose focus geometry in a 13 cm long YAG crystal, allowing for stable and robust single-filament generation. The SC energy stability exceeds that of the pump laser by almost a factor of 3. Additionally, we show that the SC spectrum has long-term stability and that the SC is coherent and compressible by compressing the portions of SC spectra close to the corresponding Fourier limit. This makes the picosecond-pulse-driven SC a suitable stable seed for OPCPA amplifiers.

  20. Self-similar anomalous diffusion and Levy-stable laws

    International Nuclear Information System (INIS)

    Uchaikin, Vladimir V

    2003-01-01

    Stochastic principles for constructing the process of anomalous diffusion are considered, and corresponding models of random processes are reviewed. The self-similarity and the independent-increments principles are used to extend the notion of diffusion process to the class of Levy-stable processes. Replacing the independent-increments principle with the renewal principle allows us to take the next step in generalizing the notion of diffusion, which results in fractional-order partial space-time differential equations of diffusion. Fundamental solutions to these equations are represented in terms of stable laws, and their relationship to the fractality and memory of the medium is discussed. A new class of distributions, called fractional stable distributions, is introduced. (reviews of topical problems)

  1. Stable solitons of quadratic ginzburg-landau equations

    Science.gov (United States)

    Crasovan; Malomed; Mihalache; Mazilu; Lederer

    2000-07-01

    We present a physical model based on coupled Ginzburg-Landau equations that supports stable temporal solitary-wave pulses. The system consists of two parallel-coupled cores, one having a quadratic nonlinearity, the other one being effectively linear. The former core is active, with bandwidth-limited amplification built into it, while the latter core has only losses. Parameters of the model can be easily selected so that the zero background is stable. The model has nongeneric exact analytical solutions in the form of solitary pulses ("dissipative solitons"). Direct numerical simulations, using these exact solutions as initial configurations, show that they are unstable; however, the evolution initiated by the exact unstable solitons ends up with nontrivial stable localized pulses, which are very robust attractors. Direct simulations also demonstrate that the presence of group-velocity mismatch (walkoff) between the two harmonics in the active core makes the pulses move at a constant velocity, but does not destabilize them.

  2. Do planetary seasons play a role in attaining stable climates?

    Science.gov (United States)

    Olsen, Kasper Wibeck; Bohr, Jakob

    2018-02-01

    A simple phenomenological account for planetary climate instabilities is presented. The description is based on the standard model where the balance of incoming stellar radiation and outward thermal radiation is described by the effective planet temperature. Often, it is found to have three different points, or temperatures, where the influx of radiation is balanced with the out-flux, even with conserved boundary conditions. Two of these points are relatively long-term stable, namely the point corresponding to a cold climate and the point corresponding to a hot climate. In a classical sense these points are equilibrium balance points. The hypothesis promoted in this paper is the possibility that the intermediate third point can become long-term stable by being driven dynamically. The initially unstable point is made relatively stable over a long period by the presence of seasonal climate variations.

  3. Embedded Controller Design for Pig Stable Ventilation Systems

    DEFF Research Database (Denmark)

    Jessen, Jan Jacob

    present an early result for performing system identification for zone based climate dynamics, based on an idea of guaranteed internal flow directions. Paper 6 presents a verified stable distributed temperature controller for pig stables divided into zones. Paper 7 is an expanded journal version of paper 6......This thesis focuses on zone based climate control in pig stables and how to implement climate controllers in a new range of products. The presented controllers are based on simple models of climate dynamics and simple models of actuators. The implementation uses graphical point and click features...... from the Mathworks' range of products and automatic code generation. It is furthermore shown how to build new climate control systems based on cheap and readily available hardware and software. An early result for performing system identification for zone based climate dynamics is also presented...

  4. Ranking stability and super-stable nodes in complex networks.

    Science.gov (United States)

    Ghoshal, Gourab; Barabási, Albert-László

    2011-07-19

    Pagerank, a network-based diffusion algorithm, has emerged as the leading method to rank web content, ecological species and even scientists. Despite its wide use, it remains unknown how the structure of the network on which it operates affects its performance. Here we show that for random networks the ranking provided by pagerank is sensitive to perturbations in the network topology, making it unreliable for incomplete or noisy systems. In contrast, in scale-free networks we predict analytically the emergence of super-stable nodes whose ranking is exceptionally stable to perturbations. We calculate the dependence of the number of super-stable nodes on network characteristics and demonstrate their presence in real networks, in agreement with the analytical predictions. These results not only deepen our understanding of the interplay between network topology and dynamical processes but also have implications in all areas where ranking has a role, from science to marketing.

  5. Source Partitioning Using Stable Isotopes: Coping with Too Much Variation

    Science.gov (United States)

    Parnell, Andrew C.; Inger, Richard; Bearhop, Stuart; Jackson, Andrew L.

    2010-01-01

    Background Stable isotope analysis is increasingly being utilised across broad areas of ecology and biology. Key to much of this work is the use of mixing models to estimate the proportion of sources contributing to a mixture such as in diet estimation. Methodology By accurately reflecting natural variation and uncertainty to generate robust probability estimates of source proportions, the application of Bayesian methods to stable isotope mixing models promises to enable researchers to address an array of new questions, and approach current questions with greater insight and honesty. Conclusions We outline a framework that builds on recently published Bayesian isotopic mixing models and present a new open source R package, SIAR. The formulation in R will allow for continued and rapid development of this core model into an all-encompassing single analysis suite for stable isotope research. PMID:20300637

  6. Stable Isotope Ratios as Biomarkers of Diet for Health Research

    Science.gov (United States)

    O’Brien, Diane M.

    2016-01-01

    Diet is a leading modifiable risk factor for chronic disease, but it remains difficult to measure accurately due to the error and bias inherent in self-reported methods of diet assessment. Consequently there is a pressing need for more objective biomarkers of diet for use in health research. The stable isotope ratios of light elements are a promising set of candidate biomarkers because they vary naturally and reproducibly among foods, and those variations are captured in molecules and tissues with high fidelity. Recent studies have identified valid isotopic measures of short and long-term sugar intake, meat intake, and fish intake in specific populations. These studies provide a strong foundation for validating stable isotopic biomarkers in the general United States population. Approaches to improve specificity for specific foods are needed, for example, by modeling intake using multiple stable isotope ratios, or by isolating and measuring specific molecules linked to foods of interest. PMID:26048703

  7. Leaf water stable isotopes and water transport outside the xylem.

    Science.gov (United States)

    Barbour, M M; Farquhar, G D; Buckley, T N

    2017-06-01

    How water moves through leaves, and where the phase change from liquid to vapour occurs within leaves, remain largely mysterious. Some time ago, we suggested that the stable isotope composition of leaf water may contain information on transport pathways beyond the xylem, through differences in the development of gradients in enrichment within the various pathways. Subsequent testing of this suggestion provided ambiguous results and even questioned the existence of gradients in enrichment within the mesophyll. In this review, we bring together recent theoretical developments in understanding leaf water transport pathways and stable isotope theory to map a path for future work into understanding pathways of water transport and leaf water stable isotope composition. We emphasize the need for a spatially, anatomically and isotopically explicit model of leaf water transport. © 2016 John Wiley & Sons Ltd.

  8. High precision and stable structures for particle detectors

    CERN Document Server

    Da Mota Silva, S; Hauviller, Claude

    1999-01-01

    The central detectors used in High Energy Physics Experiments require the use of light and stable structures capable of supporting delicate and precise radiation detection elements. These structures need to be highly stable under environmental conditions where external vibrations, high radiation levels, temperature and humidity gradients should be taken into account. Their main design drivers are high dimension and dynamic stability, high stiffness to mass ratio and large radiation length. For most applications, these constraints lead us to choose Carbon Fiber Reinforced Plastics ( CFRP) as structural element. The construction of light and stable structures with CFRP for these applications can be achieved by careful design engineering and further confirmation at the prototyping phase. However, the experimental environment can influence their characteristics and behavior. In this case, theuse of adaptive structures could become a solution for this problem. We are studying structures in CFRP with bonded piezoel...

  9. Stable isotope tracers and exercise physiology: past, present and future.

    Science.gov (United States)

    Wilkinson, Daniel J; Brook, Matthew S; Smith, Kenneth; Atherton, Philip J

    2017-05-01

    Stable isotope tracers have been invaluable assets in physiological research for over 80 years. The application of substrate-specific stable isotope tracers has permitted exquisite insight into amino acid, fatty-acid and carbohydrate metabolic regulation (i.e. incorporation, flux, and oxidation, in a tissue-specific and whole-body fashion) in health, disease and response to acute and chronic exercise. Yet, despite many breakthroughs, there are limitations to 'substrate-specific' stable isotope tracers, which limit physiological insight, e.g. the need for intravenous infusions and restriction to short-term studies (hours) in controlled laboratory settings. In recent years significant interest has developed in alternative stable isotope tracer techniques that overcome these limitations, in particular deuterium oxide (D 2 O or heavy water). The unique properties of this tracer mean that through oral administration, the turnover and flux through a number of different substrates (muscle proteins, lipids, glucose, DNA (satellite cells)) can be monitored simultaneously and flexibly (hours/weeks/months) without the need for restrictive experimental control. This makes it uniquely suited for the study of 'real world' human exercise physiology (amongst many other applications). Moreover, using D 2 O permits evaluation of turnover of plasma and muscle proteins (e.g. dynamic proteomics) in addition to metabolomics (e.g. fluxomics) to seek molecular underpinnings, e.g. of exercise adaptation. Here, we provide insight into the role of stable isotope tracers, from substrate-specific to novel D 2 O approaches, in facilitating our understanding of metabolism. Further novel potential applications of stable isotope tracers are also discussed in the context of integration with the snowballing field of 'omic' technologies. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

  10. Target-like pigmentation after minipunch grafting in stable vitiligo

    Directory of Open Access Journals (Sweden)

    Nelee Bisen

    2014-01-01

    Full Text Available Surgical treatment for vitiligo has been ever evolving. Each surgical modality has its own benefits and limitations. Miniature punch grafting is the most extensively performed surgery, which gives good results in stable vitiligo. Herein we report an unusual type of repigmentation observed after minipunch grafting in a patient of stable vitiligo, which resembled target-like lesions with a "perigraft halo" surrounding individual grafts. Such pigment spread occurred despite the use of 0.5 mm larger graft from the donor site.

  11. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2005-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeoclimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. (author). 52 refs., 11 figs., 2 tabs

  12. Coexistence of collapse and stable spatiotemporal solitons in multimode fibers

    Science.gov (United States)

    Shtyrina, Olga V.; Fedoruk, Mikhail P.; Kivshar, Yuri S.; Turitsyn, Sergei K.

    2018-01-01

    We analyze spatiotemporal solitons in multimode optical fibers and demonstrate the existence of stable solitons, in a sharp contrast to earlier predictions of collapse of multidimensional solitons in three-dimensional media. We discuss the coexistence of blow-up solutions and collapse stabilization by a low-dimensional external potential in graded-index media, and also predict the existence of stable higher-order nonlinear waves such as dipole-mode spatiotemporal solitons. To support the main conclusions of our numerical studies we employ a variational approach and derive analytically the stability criterion for input powers for the collapse stabilization.

  13. Stable propagation of interacting crack systems and modeling of damage

    International Nuclear Information System (INIS)

    Bazant, Z.P.; Tabbara, M.R.

    1989-01-01

    This paper presents general thermodynamic criteria for the stable states and stable path of structures with an interacting system of cracks. In combination with numerical finite element results for various cracked structure geometries, these criteria indicate that the crack response path of structures may exhibit bifurcations, after which the symmetry of the crack system is broken and some cracks grow preferentially. The problem is of interest for the prediction of ultimate loads, ductility and energy absorption capability of nuclear concrete structures as well as structures made of composites and ceramics

  14. Remarks on search methods for stable, massive, elementary particles

    International Nuclear Information System (INIS)

    Perl, Martin L.

    2001-01-01

    This paper was presented at the 69th birthday celebration of Professor Eugene Commins, honoring his research achievements. These remarks are about the experimental techniques used in the search for new stable, massive particles, particles at least as massive as the electron. A variety of experimental methods such as accelerator experiments, cosmic ray studies, searches for halo particles in the galaxy and searches for exotic particles in bulk matter are described. A summary is presented of the measured limits on the existence of new stable, massive particle

  15. 5-Formylcytosine can be a stable DNA modification in mammals.

    Science.gov (United States)

    Bachman, Martin; Uribe-Lewis, Santiago; Yang, Xiaoping; Burgess, Heather E; Iurlaro, Mario; Reik, Wolf; Murrell, Adele; Balasubramanian, Shankar

    2015-08-01

    5-Formylcytosine (5fC) is a rare base found in mammalian DNA and thought to be involved in active DNA demethylation. Here, we show that developmental dynamics of 5fC levels in mouse DNA differ from those of 5-hydroxymethylcytosine (5hmC), and using stable isotope labeling in vivo, we show that 5fC can be a stable DNA modification. These results suggest that 5fC has functional roles in DNA that go beyond being a demethylation intermediate.

  16. Stable three-dimensional metallic carbon with interlocking hexagons.

    Science.gov (United States)

    Zhang, Shunhong; Wang, Qian; Chen, Xiaoshuang; Jena, Puru

    2013-11-19

    Design and synthesis of 3D metallic carbon that is stable under ambient conditions has been a long-standing dream. We predict the existence of such phases, T6- and T14-carbon, consisting of interlocking hexagons. Their dynamic, mechanical, and thermal stabilities are confirmed by carrying out a variety of state-of-the-art theoretical calculations. Unlike the previously studied K4 and the simple cubic high pressure metallic phases, the structures predicted in this work are stable under ambient conditions. Equally important, they may be synthesized chemically by using benzene or polyacenes molecules.

  17. Stable patterns for fourth-order parabolic equations

    OpenAIRE

    van den Berg, J. B.; Vandervorst, R. C.

    2002-01-01

    We consider fourth-order parabolic equations of gradient type. For the sake of simplicity, the analysis is carried out for the specific equation $u\\sb t=-\\gamma\\ u\\sb {xxxx}+\\beta u\\sb {xx}-F\\sp \\prime(u)$ with $(t,x)\\in (0,\\infty)\\times(0, L)$ and $\\gamma,\\beta>0$ and where $F(u)$ is a bistable potential. We study its stable equilibria as a function of the ratio $\\gamma/beta\\sp 2$. As the ratio $\\gamma/beta\\sp 2$ crosses an explicit threshold value, the number of stable ...

  18. Thermally stable surfactants and compositions and methods of use thereof

    Science.gov (United States)

    Chaiko, David J [Woodridge, IL

    2008-09-02

    There are provided novel thermally stable surfactants for use with fillers in the preparation of polymer composites and nanocomposites. Typically, surfactants of the invention are urethanes, ureas or esters of thiocarbamic acid having a hydrocarbyl group of from 10 to 50 carbons and optionally including an ionizable or charged group (e.g., carboxyl group or quaternary amine). Thus, there are provided surfactants having Formula I: ##STR00001## wherein the variables are as defined herein. Further provided are methods of making thermally stable surfactants and compositions, including composites and nanocomposites, using fillers coated with the surfactants.

  19. Exploring cancer metabolism using stable isotope-resolved metabolomics (SIRM).

    Science.gov (United States)

    Bruntz, Ronald C; Lane, Andrew N; Higashi, Richard M; Fan, Teresa W-M

    2017-07-14

    Metabolic reprogramming is a hallmark of cancer. The changes in metabolism are adaptive to permit proliferation, survival, and eventually metastasis in a harsh environment. Stable isotope-resolved metabolomics (SIRM) is an approach that uses advanced approaches of NMR and mass spectrometry to analyze the fate of individual atoms from stable isotope-enriched precursors to products to deduce metabolic pathways and networks. The approach can be applied to a wide range of biological systems, including human subjects. This review focuses on the applications of SIRM to cancer metabolism and its use in understanding drug actions. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Stable Isotope Values of Nitrogen and Carbon in Particulate ...

    Science.gov (United States)

    Data set from “Patterns in stable isotope values of nitrogen and carbon in particulate matter from the Northwest Atlantic Continental Shelf, from the Gulf of Maine to Cape Hatteras” by Oczkowski et al. These are the data upon which all results and conclusion are made. Publishing the data allow for use by wider audience. Stable isotope dynamics on the shelf can inform both nearshore and open ocean research efforts, providing an important link along the marine continuum. To our knowledge, this data set is unique in its spatial coverage and variables measured.

  1. Stable isotope customer list and summary of shipments - FY 1983

    International Nuclear Information System (INIS)

    Davis, W.C.

    1983-12-01

    This compilation is published as an aid to those concerned with the separation and sale of stable isotopes. The information is divided into four sections: (1) alphabetical list of domestic and foreign customers, showing the stable isotopes purchased during the fiscal year; (2) alphabetical list of isotopes, cross-referenced to customer numbers and divided into domestic and foreign categories; (3) alphabetical list of states and countries, cross-referenced to customer numbers and indicating geographical concentrations of isotope users; and (4) tabulation of the shipments, quantities, and dollars for domestic, foreign, and project categories for each isotope

  2. Stable isotope customer list and summary of shipments: FY 1984

    International Nuclear Information System (INIS)

    Tracy, J.G.

    1984-12-01

    This compilation is published as an aid to those concerned with the separation and sale of stable isotopes. The information is divided into four sections: (1) alphabetical list of domestic and foreign customers, showing the stable isotopes purchased during the fiscal year; (2) alphabetical list of isotopes, cross-referenced to customer numbers and divided into domestic and foreign categories; (3) alphabetical list of states and countries, cross-referenced to customer numbers and indicating geographical concentrations of isotope users; and (4) tabulation of the shipments, quantities, and dollars for domestic, foreign, and project categories for each isotope

  3. Manipulation and gender neutrality in stable marriage procedures

    OpenAIRE

    Pini, Maria; Rossi, Francesca; Venable, Brent; Walsh, Toby

    2009-01-01

    The stable marriage problem is a well-known problem of matching men to women so that no man and woman who are not married to each other both prefer each other. Such a problem has a wide variety of practical applications ranging from matching resident doctors to hospitals to matching students to schools. A well-known algorithm to solve this problem is the Gale-Shapley algorithm, which runs in polynomial time. It has been proven that stable marriage procedures can always be manipulated. Whilst ...

  4. Using stable isotopes to characterize groundwater recharge sources in the volcanic island of Madeira, Portugal

    Science.gov (United States)

    Prada, Susana; Cruz, J. Virgílio; Figueira, Celso

    2016-05-01

    The hydrogeology of volcanic islands remains poorly understood, despite the fact that populations that live on them rely on groundwater as a primary water source. This situation is exacerbated by their complex structure, geological heterogeneity, and sometimes active volcanic processes that hamper easy analysis of their hydrogeological dynamics. Stable isotope analysis is a powerful tool that has been used to assess groundwater dynamics in complex terrains. In this work, stable isotopes are used to better understand the hydrogeology of Madeira Island and provide a case-study that can serve as a basis for groundwater studies in other similar settings. The stable isotopic composition (δ18O and δ2H) of rain at the main recharge areas of the island is determined, as well as the sources and altitudes of recharge of several springs, groundwater in tunnels and wells. The water in tunnels was found to be recharged almost exclusively by rain in the deforested high plateaus, whilst several springs associated with shallow perched aquifers are recharged from rain and cloud water interception by the vegetated slopes. Nevertheless some springs thought to be sourced from deep perched aquifers, recharge in the central plateaus, and their isotopic composition is similar to the water in the tunnels. Recharge occurs primarily during autumn and winter, as evidenced by the springs and tunnels Water Lines (WL). The groundwater in wells appears to originate from runoff from rain that falls along the slopes that infiltrates near the streams' mouths, where the wells are located. This is evident by the evaporation line along which the wells plot. Irrigation water is also a possible source of recharge. The data is compatible with the hydrogeological conceptual model of Madeira. This work also shows the importance of cloud water interception as a net contributor to groundwater recharge, at least in the perched aquifers that feed numerous springs. As the amount of rainfall is expected to

  5. Atmospherically stable nanoscale zero-valent iron particles formed under controlled air contact: characteristics and reactivity.

    Science.gov (United States)

    Kim, Hong-Seok; Ahn, Jun-Young; Hwang, Kyung-Yup; Kim, Il-Kyu; Hwang, Inseong

    2010-03-01

    Atmospherically stable NZVI (nanoscale zero-valent iron) particles were produced by modifying shell layers of Fe(H2) NZVI particles (RNIP-10DS) by using a controlled air contact method. Shell-modified NZVI particles were resistant to rapid aerial oxidation and were shown to have TCE degradation rate constants that were equivalent to 78% of those of pristine NZVI particles. Fe(H2) NZVI particles that were vigorously contacted with air (rapidly oxidized) showed a substantially compromised reactivity. Aging of shell-modified particles in water for one day resulted in a rate increase of 54%, implying that depassivation of the shell would play an important role in enhancing reactivity. Aging of shell-modified particles in air led to rate decreases by 14% and 46% in cases of one week and two months of aging, respectively. A series of instrumental analyses using transmission electron microscopy, X-ray diffractography, X-ray photoelectron spectroscopy, and X-ray absorption near-edge structure showed that the shells of modified NZVI particles primarily consisted of magnetite (Fe(3)O(4)). Analyses also implied that the new magnetite layer produced during shell modification was protective against shell passivation. Aging of shell-modified particles in water yielded another major mineral phase, goethite (alpha-FeOOH), whereas aging in air produced additional shell phases such as wustite (FeO), hematite (alpha-Fe(2)O(3)), and maghemite (gamma-Fe(2)O(3)).

  6. Stable carbon isotope discrimination: an indicator of cumulative salinity and boron stress in Eucalyptus camaldulensis.

    Science.gov (United States)

    Poss, J A; Grattan, S R; Suarez, D L; Grieve, C M

    2000-10-01

    Saplings of Eucalyptus camaldulensis Dehn. Clone 4544, irrigated with water of differing salinities (2 to 28 dS m-1) and boron concentrations (1 to 30 mg l-1), integrated the history of these stresses through the discrimination of stable isotopes of carbon in leaf and woody tissues. Carbon isotope discrimination (delta) was reduced primarily by salinity. Decreases in discrimination in response to boron stress were detected in the absence of salinity stress, but the decreases were significant only in leaf tissues with visible boron injury. Sapwood core samples indicated that salinity- and boron-induced reductions in delta increased with increasing tree age. Absolute values of delta varied with location of leaf or wood tissue, but relative effects of salinity on the relationship between delta and transpiration efficiency (W) were similar. In response to increasing salinity stress, relative decreases in delta paralleled relative decreases in biomass and both indices yielded similar salt tolerance model parameters. The strong correlations between delta, tree fresh weight, leaf area and W suggest that delta is a useful parameter for evaluating salt tolerance of eucalyptus

  7. Stable isotope analysis of precipitation samples obtained via crowdsourcing reveals the spatiotemporal evolution of Superstorm Sandy.

    Directory of Open Access Journals (Sweden)

    Stephen P Good

    Full Text Available Extra-tropical cyclones, such as 2012 Superstorm Sandy, pose a significant climatic threat to the northeastern United Sates, yet prediction of hydrologic and thermodynamic processes within such systems is complicated by their interaction with mid-latitude water patterns as they move poleward. Fortunately, the evolution of these systems is also recorded in the stable isotope ratios of storm-associated precipitation and water vapor, and isotopic analysis provides constraints on difficult-to-observe cyclone dynamics. During Superstorm Sandy, a unique crowdsourced approach enabled 685 precipitation samples to be obtained for oxygen and hydrogen isotopic analysis, constituting the largest isotopic sampling of a synoptic-scale system to date. Isotopically, these waters span an enormous range of values (> 21‰ for δ(18O, > 160‰ for δ(2H and exhibit strong spatiotemporal structure. Low isotope ratios occurred predominantly in the west and south quadrants of the storm, indicating robust isotopic distillation that tracked the intensity of the storm's warm core. Elevated values of deuterium-excess (> 25‰ were found primarily in the New England region after Sandy made landfall. Isotope mass balance calculations and Lagrangian back-trajectory analysis suggest that these samples reflect the moistening of dry continental air entrained from a mid-latitude trough. These results demonstrate the power of rapid-response isotope monitoring to elucidate the structure and dynamics of water cycling within synoptic-scale systems and improve our understanding of storm evolution, hydroclimatological impacts, and paleo-storm proxies.

  8. Stable isotope analysis of precipitation samples obtained via crowdsourcing reveals the spatiotemporal evolution of Superstorm Sandy.

    Science.gov (United States)

    Good, Stephen P; Mallia, Derek V; Lin, John C; Bowen, Gabriel J

    2014-01-01

    Extra-tropical cyclones, such as 2012 Superstorm Sandy, pose a significant climatic threat to the northeastern United Sates, yet prediction of hydrologic and thermodynamic processes within such systems is complicated by their interaction with mid-latitude water patterns as they move poleward. Fortunately, the evolution of these systems is also recorded in the stable isotope ratios of storm-associated precipitation and water vapor, and isotopic analysis provides constraints on difficult-to-observe cyclone dynamics. During Superstorm Sandy, a unique crowdsourced approach enabled 685 precipitation samples to be obtained for oxygen and hydrogen isotopic analysis, constituting the largest isotopic sampling of a synoptic-scale system to date. Isotopically, these waters span an enormous range of values (> 21‰ for δ(18)O, > 160‰ for δ(2)H) and exhibit strong spatiotemporal structure. Low isotope ratios occurred predominantly in the west and south quadrants of the storm, indicating robust isotopic distillation that tracked the intensity of the storm's warm core. Elevated values of deuterium-excess (> 25‰) were found primarily in the New England region after Sandy made landfall. Isotope mass balance calculations and Lagrangian back-trajectory analysis suggest that these samples reflect the moistening of dry continental air entrained from a mid-latitude trough. These results demonstrate the power of rapid-response isotope monitoring to elucidate the structure and dynamics of water cycling within synoptic-scale systems and improve our understanding of storm evolution, hydroclimatological impacts, and paleo-storm proxies.

  9. The activation of p38 MAPK primarily contributes to UV-induced RhoB expression by recruiting the c-Jun and p300 to the distal CCAAT box of the RhoB promoter

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Jiwon [Genome Research Center, KRIBB, Daejeon 305-806 (Korea, Republic of); Department of Microbiology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Choi, Jeong-Hae; Won, Misun [Genome Research Center, KRIBB, Daejeon 305-806 (Korea, Republic of); Kang, Chang-Mo [Laboratory of Cytogenetics and Tissue Regeneration, KIRAMS, Seoul 139-706 (Korea, Republic of); Gyun, Mi-Rang [Genome Research Center, KRIBB, Daejeon 305-806 (Korea, Republic of); Functional Genomics, Korea University of Science and Technology, Daejeon 305-350 (Korea, Republic of); Park, Hee-Moon [Department of Microbiology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Kim, Chun-Ho, E-mail: chkim@kirams.re.kr [Laboratory of Cytogenetics and Tissue Regeneration, KIRAMS, Seoul 139-706 (Korea, Republic of); Chung, Kyung-Sook, E-mail: kschung@kribb.re.kr [Genome Research Center, KRIBB, Daejeon 305-806 (Korea, Republic of)

    2011-06-03

    Highlights: {yields} Regulation of transcriptional activation of RhoB is still unclear. {yields} We examine the effect of p38 MAPK inhibition, and c-Jun and RhoB depletion on UV-induced RhoB expression and apoptosis. {yields} We identify the regions of RhoB promoter necessary to confer UV responsiveness using pRhoB-luciferase reporter assays. {yields} c-Jun, ATF2 and p300 are dominantly associated with NF-Y on the distal CCAAT box. {yields} The activation of p38 MAPK primarily contribute to UV-induced RhoB expression by recruiting the c-Jun and p300 proteins on distal CCAAT box of RhoB promoter. -- Abstract: The Ras-related small GTP-binding protein RhoB is rapidly induced in response to genotoxic stresses caused by ionizing radiation. It is known that UV-induced RhoB expression results from the binding of activating transcription factor 2 (ATF2) via NF-Y to the inverted CCAAT box (-23) of the RhoB promoter. Here, we show that the association of c-Jun with the distal CCAAT box (-72) is primarily involved in UV-induced RhoB expression and p38 MAPK regulated RhoB induction through the distal CCAAT box. UV-induced RhoB expression and apoptosis were markedly attenuated by pretreatment with the p38 MAPK inhibitor. siRNA knockdown of RhoB, ATF2 and c-Jun resulted in decreased RhoB expression and eventually restored the growth of UV-irradiated Jurkat cells. In the reporter assay using luciferase under the RhoB promoter, inhibition of RhoB promoter activity by the p38 inhibitor and knockdown of c-Jun using siRNA occurred through the distal CCAAT box. Immunoprecipitation and DNA affinity protein binding assays revealed the association of c-Jun and p300 via NF-YA and the dissociation of histone deacetylase 1 (HDAC1) via c-Jun recruitment to the CCAAT boxes of the RhoB promoter. These results suggest that the activation of p38 MAPK primarily contributes to UV-induced RhoB expression by recruiting the c-Jun and p300 proteins to the distal CCAAT box of the RhoB promoter in

  10. Efficient and facile synthesis of novel stable monodeuterium labeled ractopamine.

    Science.gov (United States)

    Su, Feifei; Wu, Fulong; Tang, He; Wang, Zhonghua; Wu, Fanhong

    2015-01-01

    A novel synthetic route to stable deuterium labeled ractopamine was disclosed with 6.49% total yield and 97.7% isotopic abundance. Its structure and the isotope-abundance were confirmed according to (1)H-NMR and high-resolution mass spectrometry. Copyright © 2015 John Wiley & Sons, Ltd.

  11. Production of stable isotopes at Urenco. 10 years of progress

    International Nuclear Information System (INIS)

    Mol, C.A.; Rakhorst, H.

    2003-01-01

    In the last ten years, Urenco has built its spin-off activity of stable isotopes in a multi-million dollar business. It is a high quality, ISO certified, client oriented and profitable European business with further growth potential. (author)

  12. The stable moduli space of Riemann surfaces: Mumford's conjecture

    DEFF Research Database (Denmark)

    Madsen, I.; Weiss, Michael

    2007-01-01

    , one may replace the stable moduli space of Riemann surfaces by $B\\Gamma_{\\infty}$, where $\\Gamma_\\infty$ is the group of isotopy classes of automorphisms of a smooth oriented connected surface of ``large'' genus. Tillmann's theorem that the plus construction makes $B\\Gamma_{\\infty}$ into an infinite...

  13. Isolation and characterization of stable mutants of Streptomyces ...

    Indian Academy of Sciences (India)

    Unknown

    Department of Genetic Engineering, School of Biotechnology, Madurai Kamaraj University, Madurai 625 021, India. Abstract. Daunorubicin and its derivative doxorubicin are antitumour anthracycline antibiotics produced by Streptomyces peucetius. In this study we report isolation of stable mutants of S. peucetius blocked in ...

  14. Recent applications of stable isotopes in environmental medicine in germany

    International Nuclear Information System (INIS)

    Krumbiegel, P.; Herbarth, O.

    2000-01-01

    In the last few years, a new quality in the application of stable isotopes became manifest. It is the establishment of stable isotopes as a tool in medical routine diagnosis - a novel field of nuclear medicine - and in environmental-medical epidemiological surveys. Owing to missing suitable radioactive isotopes of the bio elements carbon and nitrogen and because of ethical problems in the human use of some radionuclides, the stable isotopes 13 C and 1% N play a key role in this new field. A review is given about four new stable isotope-aided methods for in vivo organ function test. Three of them were developed in Leipzig, germany, and one in houston/Texas. We have validated the tests and then introduced into medical and environmental routine diagnostic use: ( 15 N Methacetin and ( 13 C) methacetin liver function tests to characterize the detoxification capacity of the human liver; ( 15 N) Urea and ( 13 C) urea tests to detect the colonization of the human stomach by the bacterium helicobacter pylori. This bacterium is, as known, responsible for gastritis and ulcer of the gastrointestinal tract. The transmission ways of H. Pylori are under investigation world-wide

  15. Preparation of stable silica surfaces for surface forces measurement

    Science.gov (United States)

    Ren, Huai-Yin; Mizukami, Masashi; Kurihara, Kazue

    2017-09-01

    A surface forces apparatus (SFA) measures the forces between two surfaces as a function of the surface separation distance. It is regarded as an essential tool for studying the interactions between two surfaces. However, sample surfaces used for the conventional SFA measurements have been mostly limited to thin (ca. 2-3 μm) micas, which are coated with silver layers (ca. 50 nm) on their back, due to the requirement of the distance determination by transmission mode optical interferometry called FECO (fringes of equal chromatic order). The FECO method has the advantage of determining the absolute distance, so it should be important to increase the availability of samples other than mica, which is chemically nonreactive and also requires significant efforts for cleaving. Recently, silica sheets have been occasionally used in place of mica, which increases the possibility of surface modification. However, in this case, the silver layer side of the sheet is glued on a cylindrical quartz disc using epoxy resin, which is not stable in organic solvents and can be easily swollen or dissolved. The preparation of substrates more stable under severe conditions, such as in organic solvents, is necessary for extending application of the measurement. In this study, we report an easy method for preparing stable silica layers of ca. 2 μm in thickness deposited on gold layers (41 nm)/silica discs by sputtering, then annealed to enhance the stability. The obtained silica layers were stable and showed no swelling in organic solvents such as ethanol and toluene.

  16. Stable limits for sums of dependent infinite variance random variables

    DEFF Research Database (Denmark)

    Bartkiewicz, Katarzyna; Jakubowski, Adam; Mikosch, Thomas

    2011-01-01

    of these results are qualitative in the sense that the parameters of the limit distribution are expressed in terms of some limiting point process. In this paper we will be able to determine the parameters of the limiting stable distribution in terms of some tail characteristics of the underlying stationary...

  17. Production and use of stable isotopes in France

    International Nuclear Information System (INIS)

    Roth, E.; Letolle, R.

    1991-01-01

    This paper can not cover the field of production and use of stable isotopes in France exhaustively within six pages. We have chosen to concentrate on highlights of the subject and on recent work, and to give references for further reading. 26 refs

  18. Divergence of stable isotopes in tap water across China

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Sihan; Hu, Hongchang; Tian, Fuqiang; Tie, Qiang; Wang, Lixin; Liu, Yaling; Shi, Chunxiang

    2017-03-02

    Stable isotopes in water (e.g., δ2H and δ18O) are important indicators of hydrological and ecological patterns and processes. Tap water can reflect integrated features of regional hydrological processes and human activities. China is a large country with significant meteorological and geographical variations. This report presents the first national-scale survey of Stable Isotopes in Tap Water (SITW) across China. 780 tap water samples have been collected from 95 cities across China from December 2014 to December 2015. (1) Results yielded the Tap Water Line in China is δ2H = 7.72 δ18O + 6.57 (r2 = 0.95). (2) SITW spatial distribution presents typical "continental effect". (3) SITW seasonal variations indicate clearly regional patterns but no trends at the national level. (4) SITW can be correlated in some parts with geographic or meteorological factors. This work presents the first SITW map in China, which sets up a benchmark for further stable isotopes research across China. This is a critical step toward monitoring and investigating water resources in climate-sensitive regions, so the human-hydrological system. These findings could be used in the future to establish water management strategies at a national or regional scale. Title: Divergence of stable isotopes in tap water across China Authors: Zhao, SH; Hu, HC; Tian, FQ; Tie, Q; Wang, LX; Liu, YL; Shi, CX Source: SCIENTIFIC REPORTS, 7 10.1038/srep43653 MAR 2 2017

  19. Stable carbon and oxygen isotope study on benthic foraminifera ...

    Indian Academy of Sciences (India)

    Ajoy K Bhaumik

    2017-07-24

    Jul 24, 2017 ... Stable isotopes of benthic foraminifera have widely been applied in micropalaeontological research to understand vital effects in foraminifera. Isotopic fractionations are mainly controlled by ontogeny, bottom/pore water chemistry, habitat preference, kinetic effect and respiration. Discontinuous abundance.

  20. Stable isotope compositions of organic carbon and contents of ...

    African Journals Online (AJOL)

    The stable isotope compositions of organic carbon (OC), and contents of OC and nitrogen for four sediment cores recovered from lakes Makat (located in the Ngorongoro Crater), Ndutu and Masek (located in the Serengeti Plains) are used to document sources of organic matter (OM) and climatic changes in sub-arid ...