Dissociative electron attachment to ozone: rate constant

International Nuclear Information System (INIS)

Skalny, J.D.; Cicman, P.; Maerk, T.D.

2002-01-01

The rate constant for dissociative electron attachment to ozone has been derived over the energy range of 0-10 eV by using previously measured cross section data revisited here in regards to discrimination effect occurring during the extraction of ions. The obtained data for both possible channels exhibit the maximum at mean electron energies close to 1 eV. (author)

Electron scattering resonances and dissociative attachment in polyatomic molecules

International Nuclear Information System (INIS)

Olthoff, J.K.

1985-01-01

A relatively new technique, electron transmission spectroscopic, is now being used to investigate the unoccupied valence molecular orbitals of many chemical compounds. Electron-transmission spectroscopy measures the energy of negative ion states that arise from electron capture into unoccupied molecular orbitals. Additional information about the unoccupied orbitals may be obtained if the negative ion decays by way of dissociation. Determination of the identity, kinetic energy, and production rates of stable ion fragments supplies information about the shape and position of the potential energy curves which describe the electronic states of the molecule and the anion. Used together, photoelectron, electron transmission, and dissociation data can produce a complete picture of a molecule's valence electronic structure. For this work, a time-of-flight mass spectrometer was attached to an electron transmission spectrometer to observe negative ion fragments due to dissociative attachment. The mass spectrometer measures the identify and kinetic energy of stable negative ions as a function of incident electron energy. Electron transmission spectra and ion production data were acquired for many compounds in four chemical categories

Resonant electron attachment to mixed hydrogen/oxygen and deuterium/oxygen clusters

Science.gov (United States)

Renzler, Michael; Kranabetter, Lorenz; Barwa, Erik; Grubwieser, Lukas; Scheier, Paul; Ellis, Andrew M.

2017-11-01

Low energy electron attachment to mixed (H2)x/(O2)y clusters and their deuterated analogs has been investigated for the first time. These experiments were carried out using liquid helium nanodroplets to form the clusters, and the effect of the added electron was then monitored via mass spectrometry. There are some important differences between electron attachment to the pure clusters and to the mixed clusters. A particularly notable feature is the formation of HO2- and H2O- ions from an electron-induced chemical reaction between the two dopants. The chemistry leading to these anions appears to be driven by electron resonances associated with H2 rather than O2. The electron resonances for H2 can lead to dissociative electron attachment (DEA), just as for the free H2 molecule. However, there is evidence that the resonance in H2 can also lead to rapid electron transfer to O2, which then induces DEA of the O2. This kind of excitation transfer has not, as far as we are aware, been reported previously.

Solvation of excess electrons trapped in charge pockets on molecular surfaces

Science.gov (United States)

Jalbout, Abraham F.

This work considers the ability of hydrogen fluoride (HF) to solvate excess electrons located on cyclic hydrocarbon surfaces. The principle applied involves the formation of systems in which excess electrons can be stabilized not only on concentrated molecular surface charge pockets but also by HF. Recent studies have shown that OH groups can form stable hydrogen-bonded networks on one side of a hydrocarbon surface (i.e. cyclohexane sheets), at the same time, the hydrogen atoms on the opposite side of this surface form a pocket of positive charge can attract the excess electron. This density can be further stabilized by the addition of an HF molecule that can form an 'anion with an internally solvated electron' (AISE) state. These systems are shown to be stable with respect to vertical electron detachment (VDE).

A technique for the measurement of electron attachment to short-lived excited species

International Nuclear Information System (INIS)

Christophorou, L.G.; Pinnaduwage, L.A.; Bitouni, A.P.

1990-01-01

A technique is described for the measurement of electron attachment to short-lived (approx-lt 10 -9 s) excited species. Preliminary results are presented for photoenhanced electron attachment to short-lived electronically-excited states of triethylamine molecules produced by laser two-photon excitation. The attachment cross sections for these excited states are estimated to be >10 -11 cm 2 and are ∼10 7 larger compared to those for the unexcited (ground-state) molecules. 8 refs., 4 figs

Dissociative electron attachment on surfaces and in bulk media

International Nuclear Information System (INIS)

Fabrikant, Ilya I.

2007-01-01

A theory of dissociative electron attachment to molecules condensed at surfaces and embedded within bulk media is developed. The theory of low-energy electron diffraction is used to obtain the width for electron-molecule resonance scattering in the condensed phase from the width for the gas phase. It is then employed for the calculation of dissociative attachment in the framework of the nonlocal complex potential theory. Specific calculations using the effective mass approximation are carried out for electron attachment to CH 3 Cl and CF 3 Cl molecules physisorbed on the surface of a Kr film. The role of image states and image-potential resonances is analyzed. The results show an increase by several orders of magnitude in the cross section for physisorbed molecules as compared with gas-phase molecules. This is in general agreement with the measured cross sections. However, the position of the peak in the cross section for CH 3 Cl is significantly shifted towards higher energies as compared to experiment [K. Nagesha et al., J. Chem. Phys. 114, 4934 (2001)], and the magnitude of the calculated cross section for CF 3 Cl at the surface is significantly higher than the measured value. Possible reasons for disagreements are analyzed

Dissociative electron attachment to methylhalides in 3-methylhexane glassy matrix

International Nuclear Information System (INIS)

Harada, K.; Irie, M.; Yoshida, H.

1976-01-01

Dissociative electron attachment reaction to CH 3 I, CH 3 Cl and CH 3 F in a 3-methylhexane glassy matrix was studied by determining the yield of trapped electrons and that of methyl radicals immediately after γ irradiation at 77 K as a function of the scavenger concentration. The efficiency of conversion from the trapped electrons to the methyl radicals was also studied by photobleaching the trapped electrons. The results obtained are (1) the dissociative electron attachment occurs to CH 3 F, for which the gas phase data indicate that the reaction is endothermic by 1.2 eV, during either the γ irradiation or the photobleaching, and (2) CH 3 F is relatively less efficient in scavenging photo-liberated electrons than in scavenging the electrons during the γ irradiation, whereas CH 3 I and CH 3 Cl are efficient scavengers for both the electrons. The dependence of the yields of the trapped electrons and the methyl radicals is discussed in terms of the electron-tunnelling mechanism and the epithermal electron-scavenging mechanism. (author)

Theoretical study of the localization of excess electrons at the surface of ice

International Nuclear Information System (INIS)

Hermann, A; Schwerdtfeger, P; Schmidt, W G

2008-01-01

The localization of excess electrons at the basal plane surface of hexagonal ice Ih is investigated theoretically, combining density functional theory (DFT) with a partial self-interaction correction (SIC) scheme, to account for spurious self-interaction effects that artificially delocalize the excess electrons. Starting from energetically favored surface geometries, we find strong localization of excess electrons at surface dangling bonds, in particular for surface adsorbed water monomers and dimers

Electron attachment to indole and related molecules

Energy Technology Data Exchange (ETDEWEB)

Modelli, Alberto, E-mail: alberto.modelli@unibo.it [Dipartimento di Chimica “G. Ciamician”, Universitá di Bologna, via Selmi 2, 40126 Bologna (Italy); Centro Interdipartimentale di Ricerca in Scienze Ambientali (CIRSA), Universitá di Bologna, via S. Alberto 163, 48123 Ravenna (Italy); Jones, Derek, E-mail: d.jones@isof.cnr.it [ISOF, Istituto per la Sintesi Organica e la Fotoreattività, C.N.R., via Gobetti 101, 40129 Bologna (Italy); Pshenichnyuk, Stanislav A., E-mail: sapsh@anrb.ru [Institute of Molecule and Crystal Physics, Ufa Research Centre, Russian Academy of Sciences, Prospekt Oktyabrya 151, 450075 Ufa (Russian Federation)

2013-11-14

Gas-phase formation of temporary negative ion states via resonance attachment of low-energy (0–6 eV) electrons into vacant molecular orbitals of indoline (I), indene (II), indole (III), 2-methylen-1,3,3-trimethylindoline (IV), and 2,3,3-trimethyl-indolenine (V) was investigated for the first time by electron transmission spectroscopy (ETS). The description of their empty-level structures was supported by density functional theory and Hartree-Fock calculations, using empirically calibrated linear equations to scale the calculated virtual orbital energies. Dissociative electron attachment spectroscopy (DEAS) was used to measure the fragment anion yields generated through dissociative decay channels of the parent molecular anions of compounds I-V, detected with a mass filter as a function of the incident electron energy in the 0–14 eV energy range. The vertical and adiabatic electron affinities were evaluated at the B3LYP/6-31+G(d) level as the anion/neutral total energy difference. The same theoretical method is also used for evaluation of the thermodynamic energy thresholds for production of the negative fragments observed in the DEA spectra. The loss of a hydrogen atom from the parent molecular anion ([M-H]{sup −}) provides the most intense signal in compounds I-IV. The gas-phase DEAS data can provide support for biochemical reaction mechanisms in vivo involving initial hydrogen abstraction from the nitrogen atom of the indole moiety, present in a variety of biologically important molecules.

Measurements of electron attachment by oxygen molecule in proportional counter

Energy Technology Data Exchange (ETDEWEB)

Tosaki, M., E-mail: tosaki.mitsuo.3v@kyoto-u.ac.jp [Radioisotope Research Center, Kyoto University, Kyoto 606-8501 (Japan); Kawano, T. [National Institute for Fusion Science, 322-6 Oroshi, Toki 509-5292 (Japan); Isozumi, Y. [Radioisotope Research Center, Kyoto University, Kyoto 606-8501 (Japan)

2013-11-15

We present pulse height measurements for 5-keV Auger electrons from a radioactive {sup 55}Fe source mounted at the inner cathode surface of cylindrical proportional counter, which is operated with CH{sub 4} admixed dry air or N{sub 2}. A clear shift of the pulse height has been observed by varying the amount of the admixtures; the number of electrons, created in the primary ionization by Auger electrons, is decreased by the electron attachment of the admixtures during their drift from the place near the source to the anode wire. The large gas amplification (typically 10{sup 4}) in the secondary ionization of proportional counter makes it possible to investigate a small change in the number of primary electrons. The electron attenuation cross-section of O{sub 2} has been evaluated by analyzing the shifts of the pulse height caused by the electron attachment to dry air and N{sub 2}.

Electron-transport, ionization, attachment, and dissociation coefficients in SF6 and its mixtures

International Nuclear Information System (INIS)

Phelps, A.V.; Van Brunt, R.J.

1988-01-01

An improved set of electron-collision cross sections is derived for SF 6 and used to calculate transport, ionization, attachment, and dissociation coefficients for pure SF 6 and mixtures of SF 6 with N 2 , O 2 , and Ne. The SF 6 cross sections differ from previously published sets primarily at very low and high electron energies. At energies below 0.03 eV the attachment cross section is adjusted to fit recent electron swarm experiments, while the elastic momentum transfer cross section is increased to the theoretical limit. At high energies an allowance is made for the excitation of highly excited levels as observed in electron beam experiments. The cross-section sets used for the admixed gases have previously been published. Electron kinetic energy distributions computed from numerical solutions of the electron-transport (Boltzmann) equation using the two-term, spherical harmonic expansion approximation were used to obtain electron-transport and reaction coefficients as functions of E/N and the fractional concentration of SF 6 . Here E is the electric field strength and N is the gas number density. Attachment rate data for low concentrations of SF 6 in N 2 are used to test the attachment cross sections. Particular attention is given to the calculation of transport and reaction coefficients at the critical E/N = (E/N)/sub c/ at which the ionization and attachment rates are equal

Dissociative electron attachment to the radiosensitizing chemotherapeutic agent hydroxyurea

Science.gov (United States)

Huber, S. E.; Śmiałek, M. A.; Tanzer, K.; Denifl, S.

2016-06-01

Dissociative electron attachment to hydroxyurea was studied in the gas phase for electron energies ranging from zero to 9 eV in order to probe its radiosensitizing capabilities. The experiments were carried out using a hemispherical electron monochromator coupled with a quadrupole mass spectrometer. Diversified fragmentation of hydroxyurea was observed upon low energy electron attachment and here we highlight the major dissociation channels. Moreover, thermodynamic thresholds for various fragmentation reactions are reported to support the discussion of the experimental findings. The dominant dissociation channel, which was observed over a broad range of energies, is associated with formation of NCO-, water, and the amidogen (NH2) radical. The second and third most dominant dissociation channels are associated with formation of NCNH- and NHCONH2-, respectively, which are both directly related to formation of the highly reactive hydroxyl radical. Other ions observed with significant abundance in the mass spectra were NH2-/O-, OH-, CN-, HNOH-, NCONH2-, and ONHCONH2-.

Single electron attachment and stripping cross sections for relativistic heavy ions

International Nuclear Information System (INIS)

Crawford, H.J.

1979-06-01

The results of a Bevalac experiment to measure the single electron attachment and stripping cross sections for relativistic (0.5 1 , and fully stripped, N 0 , ion beams emerging from the targets. Separate counters measured the number of ions in each charge state. The ratios N 1 /N 0 for different target thicknesses were fit to a simple growth curve to yield electron attachment and stripping cross sections. The data are compared to relativistic extrapolations of available theories. Clear evidence for two separate attachment processes, radiative and non-radiative, is found. Data are compared to a recently improved formulation for the stripping cross sections

Dipole-bound states as doorways in (dissociative) electron attachment

International Nuclear Information System (INIS)

Sommerfeld, Thomas

2005-01-01

This communication starts with a comparison of dissociative recombination and dissociative attachment placing emphasis on the role of resonances as reactive intermediates. The main focus is then the mechanism of electron attachment to polar molecules at very low energies (100 meV). The scheme considered consists of two steps: First, an electron is captured in a diffuse dipole-bound state depositing its energy in the vibrational degrees of freedom, in other words, a vibrational Feshbach resonance is formed. Then, owing to the coupling with a valence state, the electron is transferred into a compact valence orbital, and depending on the electron affinities of the valence state and possible dissociation products, as well as on the details of the intramolecular redistribution of vibrational energy, long-lived anions can be generated or dissociation reactions can be initiated. The key property in this context is the electronic coupling strength between the diffuse dipole-bound and the compact valence states. We describe how the coupling strength can be extracted from ab initio data, and present results for Nitromethane, Uracil and Cyanoacetylene

Excess-electron energy levels, localization and transport in disordered media

International Nuclear Information System (INIS)

Hamill, W.H.

1980-01-01

In disordered dielectrics, the fundamental parameters which control the physics and chemistry of excess electrons are time, temperature and energy or mean scattering distance. Viscosity and hardness do not directly affect the electron affinity of media, the optical spectra, or the chemical reactivity of dry or delocalized electrons or of relaxed localized or trapped electrons. Since the mean scattering distance and the transport mechanism, including barrier height, are fundamental, both liquids and glasses (including polymers) are considered in order to cover the range of relevant information. Based on the above described background, transport, localization, dry electron scavenging, trapped electron scavenging and recombination are explained. There are no available data for the energy of excess dry electrons in the media relative to vacuum in glasses, unfortunately, because of the very small yield of separated charge pairs at cryogenic temperature. Thermoplastic glassy solids provide attractive possibility above 250 K, and deserve consideration as the substitutes for cryogenic glasses. The same consideration applies to the measurements of electron drift mobility, which are essential for the adequate description of electron scavenging. (Wakatsuki, Y.)

Dissociative electron attachment studies on acetone

International Nuclear Information System (INIS)

Prabhudesai, Vaibhav S.; Tadsare, Vishvesh; Ghosh, Sanat; Gope, Krishnendu; Davis, Daly; Krishnakumar, E.

2014-01-01

Dissociative electron attachment (DEA) to acetone is studied in terms of the absolute cross section for various fragment channels in the electron energy range of 0–20 eV. H − is found to be the most dominant fragment followed by O − and OH − with only one resonance peak between 8 and 9 eV. The DEA dynamics is studied by measuring the angular distribution and kinetic energy distribution of fragment anions using Velocity Slice Imaging technique. The kinetic energy and angular distribution of H − and O − fragments suggest a many body break-up for the lone resonance observed. The ab initio calculations show that electron is captured in the multi-centered anti-bonding molecular orbital which would lead to a many body break-up of the resonance

Positron Spur Reactions with Excess Electrons and Anions in Liquid Organic Mixtures of Electron Acceptors

DEFF Research Database (Denmark)

Lévay, B.; Mogensen, O. E.

1980-01-01

By means of the positron lifetime technique we have measured positronium (Ps) yields in mixtures of nonpolar liquids with various electron scavengers which bind the electron fairly weakly (1–2 eV) in stable anions. The results are discussed with reference to recent excess electron works, and new...... experiments on anions and excess electrons are proposed. The minimum of the Ps yield versus CS2 concentration curves caused by partly delocalization of electrons on several scavenger molecules, which was observed previously in saturated aliphatic hydrocarbons occurred also in the saturated cyclic hydrocarbon...... cyclohexane, but did not appear in the aromatic benzene. This might be explained by the weak electron acceptor property of aromatics. In the Ps yield versus SF6 concentration curve in hexane a similar minimum appeared as in the CS2 case, probably by the same reason. By adding 0.8 M CS2 to the system...

s-wave threshold in electron attachment - Observations and cross sections in CCl4 and SF6 at ultralow electron energies

Science.gov (United States)

Chutjian, A.; Alajajian, S. H.

1985-01-01

The threshold photoionization method was used to study low-energy electron attachment phenomena in and cross sections of CCl4 and SF6 compounds, which have applications in the design of gaseous dielectrics and diffuse discharge opening switches. Measurements were made at electron energies from below threshold to 140 meV at resolutions of 6 and 8 meV. A narrow resolution-limited structure was observed in electron attachment to CCl4 and SF6 at electron energies below 10 meV, which is attributed to the divergence of the attachment cross section in the limit epsilon, l approaches zero. The results are compared with experimental collisional-ionization results, electron-swarm unfolded cross sections, and earlier threshold photoionization data.

Stratospheric ozone conservation by electron attachment to chlorine atoms: The negative-ion chemistry

International Nuclear Information System (INIS)

Ho, D.D.M.; Tsang, K.T.; Wong, A.Y.; Siverson, R.J.

1990-01-01

Creating low-energy electrons in the stratosphere by photoelectric emission has the beneficial effect of suppressing ozone destruction by Cl. This is because Cl is converted to Cl - , which is less reactive. Critical to the success of this scheme is the ability to attach most of the electrons to Cl - and its hydrates Cl - (H 2 O). We found that this attachment efficiency is rather high. This is remarkable given the fact that the electron affinity of Cl - is less than that of NO 3 -. Photoddetachment of NO 3 - is the key factor that leads to this high efficiency. Computer calculations show that ozone increases with electron injection, and most of the electrons end up attaching to Cl - (H 2 O). We also point out that 40 km, the altitude at which most of the ozone destruction occurs, is also the optimum altitude for injecting photoelectric electrons. 12 refs., 6 figs

Dissociative electron attachment studies on acetone

Energy Technology Data Exchange (ETDEWEB)

Prabhudesai, Vaibhav S., E-mail: vaibhav@tifr.res.in; Tadsare, Vishvesh; Ghosh, Sanat; Gope, Krishnendu; Davis, Daly; Krishnakumar, E. [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India)

2014-10-28

Dissociative electron attachment (DEA) to acetone is studied in terms of the absolute cross section for various fragment channels in the electron energy range of 0–20 eV. H{sup −} is found to be the most dominant fragment followed by O{sup −} and OH{sup −} with only one resonance peak between 8 and 9 eV. The DEA dynamics is studied by measuring the angular distribution and kinetic energy distribution of fragment anions using Velocity Slice Imaging technique. The kinetic energy and angular distribution of H{sup −} and O{sup −} fragments suggest a many body break-up for the lone resonance observed. The ab initio calculations show that electron is captured in the multi-centered anti-bonding molecular orbital which would lead to a many body break-up of the resonance.

Mechanism of electron attachment to van der Waals clusters: Application to carbon dioxide clusters

International Nuclear Information System (INIS)

Tsukada, M.; Shima, N.; Tsuneyuki, S.; Kageshima, H.; Kondow, T.

1987-01-01

A theory on the attachment of very slow electrons to van der Waals clusters was developed on the basis of the electronic structure theory, and was applied to clarify the mechanism of the collisional electron transfer from a high-Rydberg atom to a CO 2 cluster. The strong coupled electron--phonon model is found to afford a reasonable mechanism of the attachment. The equilibrium geometry of (CO 2 )/sub N/ (2≤N≤13) clusters are determined and their vertical affinity levels are obtained by the DV-X α-transition state method. Using this information, as well as some plausible assumptions on the values of the coupling constants, the attachment cross section σ is evaluated as a function of the energy of the incident electron. The theory predicts the existence of the threshold cluster size for the attachment and a sharp decrease of σ with the energy, which are consistent with the experimental results

Effects of temperature and isotopic substitution on electron attachment dynamics of guanine–cytosine base pair: Ring-polymer and classical molecular dynamics simulations

International Nuclear Information System (INIS)

Minoshima, Yusuke; Seki, Yusuke; Takayanagi, Toshiyuki; Shiga, Motoyuki

2016-01-01

Highlights: • Dynamics of excess electron attachment to guanine–cytosine base pair. • Ring-polymer and classical molecular dynamics simulations are performed. • Temperature and isotope substitution effects are investigated. - Abstract: The dynamical process of electron attachment to a guanine–cytosine pair in the normal (h-GC) and deuterated (d-GC) forms has been studied theoretically by semiclassical ring-polymer molecular dynamics (RPMD) simulations using the empirical valence bond model. The initially formed dipole-bound anion is converted rapidly to the valence-bound anion within about 0.1 ps in both h-GC and d-GC. However, the subsequent proton transfer in h-GC occurs with a rate five times greater than the deuteron transfer in d-GC. The change of rates with isotopic substitution and temperature variation in the RPMD simulations are quantitatively and qualitatively different from those in the classical molecular dynamics (MD) simulations, demonstrating the importance of nuclear quantum effects on the dynamics of this system.

Effects of temperature and isotopic substitution on electron attachment dynamics of guanine–cytosine base pair: Ring-polymer and classical molecular dynamics simulations

Energy Technology Data Exchange (ETDEWEB)

Minoshima, Yusuke; Seki, Yusuke [Department of Chemistry, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama 338-8570 (Japan); Takayanagi, Toshiyuki, E-mail: tako@mail.saitama-u.ac.jp [Department of Chemistry, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama 338-8570 (Japan); Shiga, Motoyuki [Center for Computational Science and E-Systems, Japan Atomic Energy Agency, 148-4, Kashiwanoha Campus, 178-4 Wakashiba, Kashiwa, Chiba 277-0871 (Japan)

2016-06-15

Highlights: • Dynamics of excess electron attachment to guanine–cytosine base pair. • Ring-polymer and classical molecular dynamics simulations are performed. • Temperature and isotope substitution effects are investigated. - Abstract: The dynamical process of electron attachment to a guanine–cytosine pair in the normal (h-GC) and deuterated (d-GC) forms has been studied theoretically by semiclassical ring-polymer molecular dynamics (RPMD) simulations using the empirical valence bond model. The initially formed dipole-bound anion is converted rapidly to the valence-bound anion within about 0.1 ps in both h-GC and d-GC. However, the subsequent proton transfer in h-GC occurs with a rate five times greater than the deuteron transfer in d-GC. The change of rates with isotopic substitution and temperature variation in the RPMD simulations are quantitatively and qualitatively different from those in the classical molecular dynamics (MD) simulations, demonstrating the importance of nuclear quantum effects on the dynamics of this system.

Low energy electron attachment to SF6 in N2, Ar, and Xe buffer gases

International Nuclear Information System (INIS)

Hunter, S.R.; Carter, J.G.; Christophorou, L.G.

1989-01-01

The electron attachment rate constants k/sub a/ for SF 6 have been measured in dilute mixtures of SF 6 in high pressure (>1 atm) N 2 , Ar, and Xe buffer gases at room temperature (T≅300 K) over a wide E/N range (electric field strength to gas number density ratio), corresponding to mean electron energies from near thermal electron energies (≅0.04 eV) to ≅4.3 eV. Particular attention has been paid to the effects of space charge distortion, molecular impurities, and changes in the electron energy distribution function on the measured electron attachment rate constant values at the lower E/N values in these mixtures. The present measured thermal electron attachment rate constants in SF 6 /N 2 and SF 6 /Xe gas mixtures are in excellent agreement with recent accurate measurements of these parameters in several SF 6 /buffer gas mixtures. At higher values, the present SF 6 /N 2 measurements are in fair agreement with previous measurements, while no previous measurements using Ar and Xe buffer gases have been published. These measurements have been used in numerical two term, spherical harmonic Boltzmann equation analyses of the electron motion in these gas mixtures to obtain the low energy ( 6 . The present derived electron attachment cross sections are compared with recently measured and derived nondissociative and dissociative electron attachment cross sections for SF 6

46 CFR 67.218 - Optional filing of instruments in portable document format as attachments to electronic mail.

Science.gov (United States)

2010-10-01

... format as attachments to electronic mail. 67.218 Section 67.218 Shipping COAST GUARD, DEPARTMENT OF... format as attachments to electronic mail. (a) Any instrument identified as eligible for filing and recording under § 67.200 may be submitted in portable document format (.pdf) as an attachment to electronic...

Dissociative electron attachment to the radiosensitizing chemotherapeutic agent hydroxyurea

Energy Technology Data Exchange (ETDEWEB)

Huber, S. E.; Tanzer, K.; Denifl, S. [Institute for Ion Physics and Applied Physics and Center of Molecular Biosciences Innsbruck, Leopold Franzens University of Innsbruck, Technikerstr. 25, 6020 Innsbruck (Austria); Śmiałek, M. A., E-mail: smialek@pg.gda.pl [Department of Control and Power Engineering, Faculty of Ocean Engineering and Ship Technology, Gdańsk University of Technology, Gabriela Narutowicza 11/12, 80-233 Gdańsk (Poland)

2016-06-14

Dissociative electron attachment to hydroxyurea was studied in the gas phase for electron energies ranging from zero to 9 eV in order to probe its radiosensitizing capabilities. The experiments were carried out using a hemispherical electron monochromator coupled with a quadrupole mass spectrometer. Diversified fragmentation of hydroxyurea was observed upon low energy electron attachment and here we highlight the major dissociation channels. Moreover, thermodynamic thresholds for various fragmentation reactions are reported to support the discussion of the experimental findings. The dominant dissociation channel, which was observed over a broad range of energies, is associated with formation of NCO{sup −}, water, and the amidogen (NH{sub 2}) radical. The second and third most dominant dissociation channels are associated with formation of NCNH{sup −} and NHCONH{sub 2}{sup −}, respectively, which are both directly related to formation of the highly reactive hydroxyl radical. Other ions observed with significant abundance in the mass spectra were NH{sub 2}{sup −}/O{sup −}, OH{sup −}, CN{sup −}, HNOH{sup −}, NCONH{sub 2}{sup −}, and ONHCONH{sub 2}{sup −}.

CRESU studies of electron attachment and Penning ionization at temperatures down to 48 K

International Nuclear Information System (INIS)

Le Garrec, J.L.; Mitchell, J.B.A.; Rowe, B.R.

1996-01-01

The object of the present report is to present results obtained for electron attachment and Penning ionization, obtained with the addition of a Langmuir probe to the measurement apparatus. Measurements of the rate coefficients for electron attachment and Penning ionization are performed using the standard techniques for the flow reactors. Rate coefficients for the Penning ionisation of argon, nitrogen molecule, oxygen molecule by helium metastable are presented. The results obtained concerning the attachment of electrons to SF 6 (non-dissociative), CCl 2 F 2 (producing Cl - ), and CF 3 Br as a function of temperature are presented. The differences observed, and the variation of the value of β below 100 K, provides evidence of the strong influence of the internal state (probably vibrational) of the CF 3 Br molecule on its dissociative attachment

Excess electron transport and delayed muonium formation in condensed rare gases

International Nuclear Information System (INIS)

Eshchenko, D.G.; Storchak, V.G.; Brewer, J.H.; Morris, G.D.; Cottrell, S.P.; Cox, S.F.J.

2002-01-01

Experimental studies of excess electron transport in solid and liquid phases of Ne and Ar are presented and compared with those for He. The technique of muon spin relaxation in frequently reversed electric fields was used to study the phenomenon of delayed muonium formation, whereby excess electrons liberated in the μ + ionization track converge upon the positive muons and form μ + e - atoms. This process is shown to be crucially dependent upon the electron's interaction with its environment (i.e., whether it occupies the conduction band or becomes localized) and upon its mobility in these states. The characteristic lengths involved are 10 -6 to 10 -4 cm; the characteristic times range from nanoseconds to tens of microseconds. Such a microscopic length scale sometimes enables the electron to spend its entire free lifetime in a state which may not be detected by conventional macroscopic techniques. The end-of-track processes are compared in (i) liquid and solid helium (where the electron is known to be localized in a bubble in the liquid phase and is thought to behave in a similar manner in the solid); (ii) liquid and solid neon (where both localized and bandlike electrons are found in the liquid phase while most are delocalized in the solid); and (iii) liquid and solid argon (where most electrons are bandlike in both phases). This scaling from light to heavy rare gases enables us to demonstrate new features of excess electron localization on the microscopic scale and provides insight into the structure of the end of the muon track in condensed rare gases

Electron transfer from electronic excited states to sub-vacuum electron traps in amorphous ice

International Nuclear Information System (INIS)

Vichnevetski, E.; Bass, A.D.; Sanche, L.

2000-01-01

We investigate the electron stimulated yield of electronically excited argon atoms (Ar * ) from monolayer quantities of Ar deposited onto thin films of amorphous ice. Two peaks of narrow width ( - electron-exciton complex into exciton states, by the transfer of an electron into a sub-vacuum electron state within the ice film. However, the 10.7 eV feature is shifted to lower energy since electron attachment to Ar occurs within small pores of amorphous ice. In this case, the excess electron is transferred into an electron trap below the conduction band of the ice layer

Ab initio study of dissociative attachment of low-energy electrons to F2

International Nuclear Information System (INIS)

Hazi, A.U.; Orel, A.E.; Rescigno, T.N.

1981-01-01

Adiabatic-nuclei resonance theory has been applied to the study of dissociative attachment of low-energy electrons to F 2 . Stieltjes moment theory was used to derive fixed-nuclei electronic resonance parameters from large scale configuration-interaction calculations on F 2 and F 2 - . Dissociative attachment cross sections are reported for the four lowest vibrational levels of F 2 and compared to available experimental data

New concept of gas purification by electron attachment

International Nuclear Information System (INIS)

Tamon, Hajime; Mizota, Hirotoshi; Sano, Noriaki; Schulze, S.; Okazaki, Morio

1995-01-01

Recently, the public has become interested in the following types of gas purification: (1) removal of indoor air pollutants; (2) complete removal of dioxin from incineration plants; (3) complete removal of radioactive iodine compounds; (4) simultaneous removal of NOx and SOx in exhaust gases from cogeneration plants; (5) removal and decomposition of halocarbons; (6) ultrahigh purification of gas sued for semiconductor industries. A new concept of gas purification by electron attachment is proposed. Low-energy electrons generated in a corona-discharge reactor are captured by electronegative impurities, producing negative ions. The ions drift to the anode in the electric field and are removed at the anode of the reactor. Two types of reactors were used to remove the negative ions: a deposition-type reactor, which deposits negative ions at the anode surface; a sweep-out-type reactor, which sweeps out enriched electronegative impurities through the porous anode. Removals of dilute sulfur compounds, oxygen and iodine from nitrogen were conducted to verify the concept of gas purification. Simulation models were used to estimate removal efficiencies of these compounds, by taking into account electron attachment, and experimental constants of the models were determined. The removal efficiency correlated by the models agreed well with the experimental one

Low energy electron attachment to cyanamide (NH{sub 2}CN)

Energy Technology Data Exchange (ETDEWEB)

Tanzer, Katrin; Denifl, Stephan, E-mail: Andrzej.Pelc@poczta.umcs.lublin.pl, E-mail: Stephan.Denifl@uibk.ac.at [Institut für Ionenphysik und Angewandte Physik, Leopold Franzens Universität Innsbruck, Technikerstr. 25, 6020 Innsbruck (Austria); Pelc, Andrzej, E-mail: Andrzej.Pelc@poczta.umcs.lublin.pl, E-mail: Stephan.Denifl@uibk.ac.at [Mass Spectrometry Department, Institute of Physics, Marie Curie-Sklodowska University, Pl. M. C.-Sklodowskiej 1, 20-031 Lublin (Poland); Huber, Stefan E. [Institut für Ionenphysik und Angewandte Physik, Leopold Franzens Universität Innsbruck, Technikerstr. 25, 6020 Innsbruck (Austria); Lehrstuhl für Theoretische Chemie, Technische Universität München, Lichtenbergstr. 4, 85747 Garching (Germany); Czupyt, Z. [Ion Microprobe Facility Micro-area Analysis Laboratory, Polish Geological Institute–National Research Institute, Rakowiecka 4, 00-975 Warszawa (Poland)

2015-01-21

Cyanamide (NH{sub 2}CN) is a molecule relevant for interstellar chemistry and the chemical evolution of life. In the present investigation, dissociative electron attachment to NH{sub 2}CN has been studied in a crossed electron–molecular beams experiment in the electron energy range from about 0 eV to 14 eV. The following anionic species were detected: NHCN{sup −}, NCN{sup −}, CN{sup −}, NH{sub 2}{sup −}, NH{sup −}, and CH{sub 2}{sup −}. The anion formation proceeds within two broad electron energy regions, one between about 0.5 and 4.5 eV and a second between 4.5 and 12 eV. A discussion of possible reaction channels for all measured negative ions is provided. The experimental results are compared with calculations of the thermochemical thresholds of the anions observed. For the dehydrogenated parent anion, we explain the deviation between the experimental appearance energy of the anion with the calculated corresponding reaction threshold by electron attachment to the isomeric form of NH{sub 2}CN—carbodiimide.

Flexible Sensing Electronics for Wearable/Attachable Health Monitoring.

Science.gov (United States)

Wang, Xuewen; Liu, Zheng; Zhang, Ting

2017-07-01

Wearable or attachable health monitoring smart systems are considered to be the next generation of personal portable devices for remote medicine practices. Smart flexible sensing electronics are components crucial in endowing health monitoring systems with the capability of real-time tracking of physiological signals. These signals are closely associated with body conditions, such as heart rate, wrist pulse, body temperature, blood/intraocular pressure and blood/sweat bio-information. Monitoring such physiological signals provides a convenient and non-invasive way for disease diagnoses and health assessments. This Review summarizes the recent progress of flexible sensing electronics for their use in wearable/attachable health monitoring systems. Meanwhile, we present an overview of different materials and configurations for flexible sensors, including piezo-resistive, piezo-electrical, capacitive, and field effect transistor based devices, and analyze the working principles in monitoring physiological signals. In addition, the future perspectives of wearable healthcare systems and the technical demands on their commercialization are briefly discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Can an Excess Electron Localise on a Purine Moiety in the Adenine-thymine Watson-Crick Base Pair? A Computational Study

International Nuclear Information System (INIS)

Mazurkiewicz, Kamil; Haranczyk, Maciej; Gutowski, Maciej S.; Rak, Janusz

2007-01-01

The electron affinity and the propensity to electron-induced proton transfer (PT) of hydrogen-bonded complexes between the Watson-Crick adenine-thymine pair (AT) and simple organic acid (HX), attached to adenine in the Hoogsteen-type configuration, were studied at the B3LYP/6-31+G** level. Although the carboxyl group is deprotonated at physiological pH, its neutral form, COOH, resembles the peptide bond or the amide fragment in the side chain of asparagine (Asn) or glutamine (Gln). Thus, these complexes mimic the interaction between the DNA environment (e.g., proteins) and nucleobase pairs incorporated in the biopolymer. Electron attachment is thermodynamically feasible and adiabatic electron affinities range from 0.41 to 1.28 eV, while the vertical detachment energies of the resulting anions span the range of 0.39-2.88 eV. Low-energy activation barriers separate the anionic minima: aHX(AT) from the more stable single-PT anionic geometry, aHX(AT)-SPT, and aHX(AT)-SPT from the double-PT anionic geometry, aHX(AT)-DPT. Interaction between the adenine of the Watson-Crick AT base pair with an acidic proton donor probably counterbalances the larger EA of isolated thymine, as SOMO is almost evenly delocalized over both types of nucleic bases in the aHX(AT) anions. Moreover, as a result of PT the excess electron localizes entirely on adenine. Thus, in DNA interacting with its physiological environment, damage induced by low-energy electrons could begin, contrary to the current view, with the formation of purine anions, which are not formed in isolated DNA because of the greater stability of anionic pyrimidines.

Low energy electron attachment to the uracil molecule

International Nuclear Information System (INIS)

Hanel, G.; Gstir, B.; Denifl, S.; Scheier, P.; Maerk, T.D.; Farizon, B.; Farizon, M.

2002-01-01

Using a recently constructed high resolution crossed beam apparatus involving a hemispherical electron monochromator, electron attachment to the uracil molecule C 4 H 4 N 2 O 2 was studied. The electron energy range investigated was in the region between 0 and 12 eV. What will happen when slow electrons are colliding with the cellular RNA compound uracil was the objective of this investigation. The following anion fragments were detected: (C 4 H 3 N 2 O 2 ) - , OCN - , (H 2 C 3 NO) - , CN - , O - . The most important result was that within the detection efficiency any traces of the parent anion were observed. The most intense fragment anion appeared on a mass to charge ratio 111 amu., it corresponds to a uracil molecule missing one hydrogen. Another observation was whereas the parent minus H anion is observed at zero electron energy, all other fragments appear in other range. (nevyjel)

Electron localization in water clusters

International Nuclear Information System (INIS)

Landman, U.; Barnett, R.N.; Cleveland, C.L.; Jortner, J.

1987-01-01

Electron attachment to water clusters was explored by the quantum path integral molecular dynamics method, demonstrating that the energetically favored localization mode involves a surface state of the excess electron, rather than the precursor of the hydrated electron. The cluster size dependence, the energetics and the charge distribution of these novel electron-cluster surface states are explored. 20 refs., 2 figs., 1 tab

Velocity slice imaging for dissociative electron attachment

Science.gov (United States)

Nandi, Dhananjay; Prabhudesai, Vaibhav S.; Krishnakumar, E.; Chatterjee, A.

2005-05-01

A velocity slice imaging method is developed for measuring the angular distribution of fragment negative ions arising from dissociative electron attachment (DEA) to molecules. A low energy pulsed electron gun, a pulsed field ion extraction, and a two-dimensional position sensitive detector consisting of microchannel plates and a wedge-and-strip anode are used for this purpose. Detection and storage of each ion separately for its position and flight time allows analysis of the data offline for any given time slice, without resorting to pulsing the detector bias. The performance of the system is evaluated by measuring the angular distribution of O- from O2 and comparing it with existing data obtained using conventional technique. The capability of this technique in obtaining forward and backward angular distribution data is shown to have helped in resolving one of the existing problems in the electron scattering on O2.

The drift velocity of excess electrons in fluid methane, argon and mixtures of methane and argon

International Nuclear Information System (INIS)

Engels, J.M.L.

1979-01-01

A description is given of an experimental investigation of the drift velocity of excess electrons in fluid methane at temperatures between 91K and 215K, and at pressures up to 65X10 5 Pa. These measurements that have become possible especially due to the improved purification techniques of the liquids under investigation. The purification prevents the electron from being captured too soon by an electron-impurity. From the results of the measurements in methane it appeared that in some respects the behaviour of excess electrons in methane is qualitatively similar to that in argon. For this reason a number of measurements of the electron drift velocity have been carried out in argon and in mixtures of methane and argon as well. A detailed description of the experimental set-up is presented. The excess electrons are generated with a high-voltage electron gun, which produces a pulse of highly energetic electrons. A fraction of these electrons enters the liquid sample by passing through a thin metal foil which separates the liquid sample and the vacuum present in the electron gun. At the same time the foil is used as one of two plane-parallel electrodes of the measuring capacitor in which the drift velocity of the excess electrons is to be measured. (Auth.)

Hydration of excess electrons trapped in charge pockets on molecular surfaces

Science.gov (United States)

Jalbout, Abraham F.; Del Castillo, R.; Adamowicz, Ludwik

2007-01-01

In this work we strive to design a novel electron trap located on a molecular surface. The process of electron trapping involves hydration of the trapped electron. Previous calculations on surface electron trapping revealed that clusters of OH groups can form stable hydrogen-bonded networks on one side of a hydrocarbon surface (i.e. cyclohexane sheets), while the hydrogen atoms on the opposite side of the surface form pockets of positive charge that can attract extra negative charge. The excess electron density on such surfaces can be further stabilized by interactions with water molecules. Our calculations show that these anionic systems are stable with respect to vertical electron detachment (VDE).

Excess electrons at anatase TiO2 surfaces and interfaces: insights from first principles simulations

Science.gov (United States)

Selçuk, Sencer; Selloni, Annabella

2017-07-01

TiO2 is an important technological material with widespread applications in photocatalysis, photovoltaics and self-cleaning surfaces. Excess electrons from intrinsic defects, dopants and photoexcitation play a key role in the properties of TiO2 that are relevant to its energy-related applications. The picture of excess and photoexcited electrons in TiO2 is based on the polaron model, where the electron forms a localized state that is stabilized by an accompanying lattice distortion. Here, we focus on excess and photoexcited electrons in anatase, the TiO2 polymorph most relevant to photocatalysis and solar energy conversion. For anatase, evidence of both small and large electron polarons has been reported in the literature. In addition, several studies have revealed a remarkable dependence of the photocatalytic activity of anatase on the crystal surface. After an overview of experimental studies, we briefly discuss recent progress in the theoretical description of polaronic states in TiO2, and finally present a more detailed account of our computational studies on the trapping and dynamics of excess electrons near the most common anatase surfaces and aqueous interfaces. The results of these studies provide a bridge between surface science experiments under vacuum conditions and observations of crystal-face-dependent photocatalysis on anatase, and support the idea that optimization of the ratio between different anatase facets can help enhance the photocatalytic activity of this material.

s-wave threshold in electron attachment - Results in 2-C4F6 and CFCl3 at ultra-low electron energies

Science.gov (United States)

Chutjian, A.; Alajajian, S. H.; Ajello, J. M.; Orient, O. J.

1984-01-01

Electron attachment lineshapes and cross sections are reported for the processes 2-C4F6(-)/2-C4F6 and Cl(-)/CFCl3 at electron energies of 0-120 and 0-140 meV, and at resolutions of 6 and 7 meV (FWHM), respectively. As in previous measurements in CCl4 and SF6, the results show resolution-limited narrow structure in the cross section at electron energies below 15 meV. This structure arises from the divergence of the s-wave cross section in the limit of zero electron energy. Comparisons are given with swarm-measured results, and with collisional ionization (high-Rydberg attachment) data in this energy range.

Dissociative electron attachment and charge transfer in condensed matter

International Nuclear Information System (INIS)

Bass, A.D.; Sanche, L.

2003-01-01

Experiments using energy-selected beams of electrons incident from vacuum upon thin vapour deposited solids show that, as in the gas-phase, scattering cross sections at low energies are dominated by the formation of temporary negative ions (or resonances) and that molecular damage may be effected via dissociative electron attachment (DEA). Recent results also show that charge transfer between anionic states of target molecules and their environment is often crucial in determining cross sections for electron driven processes. Here, we review recent work from our laboratory, in which charge transfer is observed. For rare gas solids, electron exchange between the electron-exciton complex and either a metal substrate or co-adsorbed molecule enhances the desorption of metastable atoms and/or molecular dissociation. We discuss how transient electron capture by surface electron states of a substrate and subsequent electron transfer to a molecular adsorbate enhances the effective cross sections for DEA. We also consider the case of DEA to CF 2 Cl 2 condensed on water and ammonia ices, where electron exchange between pre-solvated electron states of ice and transient molecular anions can also increase DEA cross sections. Electron transfer from molecular resonances into pre-solvated electron states of ice is also discussed

Thermal electron attachment to CHF2CL in mixtures with CO2 and N2

International Nuclear Information System (INIS)

Szamrej, I.; Jowko, J.; Forys, M.

1996-01-01

Electron attachment to CHF 2 Cl in mixtures with nitrogen and carbon dioxide has been investigated using an electron swarm method. The attachment mechanism involving both two-body process and electron capture by van der Waals complexes ((CHF 2 Cl x N 2 ) and CHF 2 Cl) was found. The corresponding rate constants are equal to (1.1 ± 0.1) x 10- 13 cm 3 molec -1 s -1 , (2.0 ± 0.1) x 10 -33 cm 6 ) molec -2 s -1 and (1.1 ± 0.1) x 10- 50 cm 9 molec -3 ) s -1 , respectively. (Author)

Dissociative electron attachment and anion-induced dimerization in pyruvic acid

Czech Academy of Sciences Publication Activity Database

Zawadzki, Mateusz; Ranković, Miloš; Kočišek, Jaroslav; Fedor, Juraj

2018-01-01

Roč. 20, č. 10 (2018), s. 6838-6844 ISSN 1463-9076 R&D Projects: GA ČR GA17-04844S; GA ČR GJ16-10995Y Institutional support: RVO:61388955 Keywords : pyruvic acid * electron attachment * dimerization Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 4.123, year: 2016

Rate coefficients for low-energy electron dissociative attachment to molecular hydrogen

International Nuclear Information System (INIS)

Horacek, J.; Houfek, K.; Cizek, M.; Murakami, I.; Kato, T.

2003-02-01

Calculation of rate constants for dissociative electron attachment to molecular hydrogen is reported. The calculation is based on an improved nonlocal resonance model of Cizek, Horacek and Domcke which takes fully into account the nonlocality of the resonance dynamics and uses potentials with correct asymptotic forms. The rate constants are calculated for all quantum numbers v and J of the target molecules and for electron temperature in the range 0-30000 K. (author)

A dissociative electron attachment cross-section estimator

International Nuclear Information System (INIS)

Munro, James J; Harrison, Stephen; Fujimoto, Milton M; Tennyson, Jonathan

2012-01-01

Dissociative electron attachment (DEA) is the major process where molecules are destroyed in low-energy plasmas. DEA cross sections are therefore important for a whole variety of applications but are both hard to measure or compute accurately. A method for estimating DEA cross sections based a simple resonance plus survival model is presented. Test results are presented for DEA of molecular oxygen and molecular chlorine, for which experimental measurements are available for comparison, and SiBr and SiBr 2 , for which no previous data is available. The estimator has been implemented as part of Quantemol-N expert system which uses the R-matrix method to predict resonance positions and widths.

30 CFR 75.1438 - End attachment replacement.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false End attachment replacement. 75.1438 Section 75.1438 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND... attachment replacement. Wire rope attachments shall be replaced when cracked, deformed, or excessively worn. ...

Three-Dimensional Computed Tomography as a Method for Finding Die Attach Voids in Diodes

Science.gov (United States)

Brahm, E. N.; Rolin, T. D.

2010-01-01

NASA analyzes electrical, electronic, and electromechanical (EEE) parts used in space vehicles to understand failure modes of these components. The diode is an EEE part critical to NASA missions that can fail due to excessive voiding in the die attach. Metallography, one established method for studying the die attach, is a time-intensive, destructive, and equivocal process whereby mechanical grinding of the diodes is performed to reveal voiding in the die attach. Problems such as die attach pull-out tend to complicate results and can lead to erroneous conclusions. The objective of this study is to determine if three-dimensional computed tomography (3DCT), a nondestructive technique, is a viable alternative to metallography for detecting die attach voiding. The die attach voiding in two- dimensional planes created from 3DCT scans was compared to several physical cross sections of the same diode to determine if the 3DCT scan accurately recreates die attach volumetric variability

Electron kinetics with attachment and ionization from higher order solutions of Boltzmann's equation

International Nuclear Information System (INIS)

Winkler, R.; Wilhelm, J.; Braglia, G.L.

1989-01-01

An appropriate approach is presented for solving the Boltzmann equation for electron swarms and nonstationary weakly ionized plasmas in the hydrodynamic stage, including ionization and attachment processes. Using a Legendre-polynomial expansion of the electron velocity distribution function the resulting eigenvalue problem has been solved at any even truncation-order. The technique has been used to study velocity distribution, mean collision frequencies, energy transfer rates, nonstationary behaviour and power balance in hydrodynamic stage, of electrons in a model plasma and a plasma of pure SF 6 . The calculations have been performed for increasing approximation-orders, up to the converged solution of the problem. In particular, the transition from dominant attachment to prevailing ionization when increasing the field strength has been studied. Finally the establishment of the hydrodynamic stage for a selected case in the model plasma has been investigated by solving the nonstationary, spatially homogeneous Boltzmann equation in twoterm approximation. (author)

Electric dipole, polarizability and structure of cesium chloride clusters with one-excess electron

International Nuclear Information System (INIS)

Jraij, A.; Allouche, A.R.; Rabilloud, F.; Korek, M.; Aubert-Frecon, M.; Rayane, D.; Compagnon, I.; Antoine, R.; Broyer, M.; Dugourd, Ph.

2006-01-01

The measurement of the electric dipole of gas phase one-excess electron Cs n Cl n-1 clusters is reported together with a theoretical ab initio prediction of stable structures, dipole moments and electronic polarizabilities for these species in their ground state. Results are in agreement with NaCl cubic structures

Two-state model of excess electron relaxation and geminate recombination in water and aqueous solutions

International Nuclear Information System (INIS)

Fedorenko, S.G.

2010-01-01

Graphical abstract: After photo-induced ionization a free electron suffers a quick conversion to a solvated state, and then recombines with the parent atom or ion. However, high mobility and reactivity of a free electron can allow the electron to delocalize and recombine in the free state. The theory of two channel processes of geminate electron recombination is developed and applied to the experiment of three-pulse generation of excess electrons in water. - Abstract: After photo-induced ionization a free electron suffers a quick conversion to a solvated state, and then can recombine with the parent atom or ion. However, high mobility and reactivity of a free electron can allow the electron to delocalize and recombine in the free state. The theory of two channel processes of geminate electron recombination is developed here for the general type of the Markovian motion of reactants. A contact model is used for analytical solution of the problem of geminate recombination of neutral and charged reactants. The theory is applied to the experiment of three-pulse generation of excess electrons in water.

Characterization of Neutral Radicals from a Dissociative Electron Attachment Process

Science.gov (United States)

Li, Zhou; Milosavljević, Aleksandar R.; Carmichael, Ian; Ptasinska, Sylwia

2017-08-01

Despite decades of gas-phase studies on dissociative electron attachment (DEA) to various molecules, as yet there has been no direct detection and characterization of the neutral radical species produced by this process. In this study, we performed stepwise electron spectroscopy to directly measure and characterize the neutrals produced upon zero-electron-energy DEA to the model molecule, carbon tetrachloride (CCl4 ). We observed the direct yield of the trichloromethyl radical (CCl3. ) formed by DEA to CCl4 and measured the appearance energies of all the other neutral species. By combining these experimental findings with high-level quantum chemical calculations, we performed a complete analysis of both the DEA to CCl4 and the subsequent electron-impact ionization of CCl3. . This work paves the way toward a complete experimental characterization of DEA processes, which will lead to a better understanding of the low-energy electron-induced formation of radical species.

Effect of cluster environment on the electron attachment to 2-nitrophenol

Czech Academy of Sciences Publication Activity Database

Kočišek, Jaroslav; Grygoryeva, Kateřina; Lengyel, Jozef; Fárník, Michal; Fedor, Juraj

2016-01-01

Roč. 70, č. 4 (2016), s. 98-105 ISSN 1434-6060 R&D Projects: GA ČR GJ16-10995Y; GA ČR GA14-14082S Institutional support: RVO:61388955 Keywords : electron attachment * cluster environment * 2-nitrophenol Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.288, year: 2016

Improving Attachments of Non-Invasive (Type III) Electronic Data Loggers to Cetaceans

Science.gov (United States)

2014-09-30

electronics technology , and resulted in highly integrated mechatronics systems for the study of free ranging animals. In the next decade, these tags will...animal performance of engineered attachments and tags Objective: Develop the tag technology and algorithms required to produce quantitative metrics for

On electron attachment effect on characteristics of the DBD in chlorine and its mixtures with xenon

Science.gov (United States)

Avtaeva, S. V.

2017-11-01

The electron attachment effect on DBD characteristics in chlorine and its mixtures with xenon has been studied. Characteristics of the DBDs in pure chlorine and in xenon-chlorine mixtures with a chlorine fraction of 0.1-5% were modeled using the fluid model. It is shown that the electron attachment limits a magnitude of the DBD current, contributes to formation of multiple current spikes, appearance of a double layer near the dielectric surface and formation of XeCl* excimer molecules, and leads to a redistribution of the power deposited into the discharge: more power is deposited into ions and less power is deposited into electrons.

Electron Attachment to C2 Fluorocarbon Radicals at High Temperature (Postprint)

Science.gov (United States)

2016-01-28

constant curve for C2F3. Figure 3 shows an extrap - olation of the electron attachment rate constant for C2F3 as a function of Tgas and Tel similar to...weight to the use of kinetic modeling to extrap - olate data taken over narrower ranges. ACKNOWLEDGMENTS The project was funded by the United States Air

Resonance electron attachment to plant hormones and its likely connection with biochemical processes

Energy Technology Data Exchange (ETDEWEB)

Pshenichnyuk, Stanislav A., E-mail: sapsh@anrb.ru [Institute of Molecule and Crystal Physics, Ufa Research Centre, Russian Academy of Sciences, Prospekt Oktyabrya 151, 450075 Ufa (Russian Federation); Modelli, Alberto [Dipartimento di Chimica “G. Ciamician”, Università di Bologna, via Selmi 2, 40126 Bologna, Italy and Centro Interdipartimentale di Ricerca in Scienze Ambientali, via S. Alberto 163, 48123 Ravenna (Italy)

2014-01-21

Gas-phase formation of temporary negative ion states via resonance attachment of low-energy (0–6 eV) electrons into vacant molecular orbitals of salicylic acid (I) and its derivatives 3-hydroxy- (II) and 4-hydroxybenzoic acid (III), 5-cloro salicylic acid (IV) and methyl salicylate (V) was investigated for the first time by electron transmission spectroscopy. The description of their empty-level structures was supported by density functional theory and Hartree-Fock calculations, using empirically calibrated linear equations to scale the calculated virtual orbital energies. Dissociative electron attachment spectroscopy (DEAS) was used to measure the fragment anion yields generated through dissociative decay channels of the parent molecular anions of compounds I–V, detected with a mass filter as a function of the incident electron energy in the 0–14 eV energy range. The most intense negative fragment produced by DEA to isomers I–III is the dehydrogenated molecular anion [M–H]{sup −}, mainly formed at incident electron energies around 1 eV. The vertical and adiabatic electron affinities were evaluated at the B3LYP/6-31+G(d) level as the anion/neutral total energy difference. The same theoretical method was also used for evaluation of the thermodynamic energy thresholds for production of the negative fragments observed in the DEA spectra. The gas-phase DEAS data can provide support for biochemical reaction mechanisms in vivo.

Resonance electron attachment to plant hormones and its likely connection with biochemical processes

International Nuclear Information System (INIS)

Pshenichnyuk, Stanislav A.; Modelli, Alberto

2014-01-01

Gas-phase formation of temporary negative ion states via resonance attachment of low-energy (0–6 eV) electrons into vacant molecular orbitals of salicylic acid (I) and its derivatives 3-hydroxy- (II) and 4-hydroxybenzoic acid (III), 5-cloro salicylic acid (IV) and methyl salicylate (V) was investigated for the first time by electron transmission spectroscopy. The description of their empty-level structures was supported by density functional theory and Hartree-Fock calculations, using empirically calibrated linear equations to scale the calculated virtual orbital energies. Dissociative electron attachment spectroscopy (DEAS) was used to measure the fragment anion yields generated through dissociative decay channels of the parent molecular anions of compounds I–V, detected with a mass filter as a function of the incident electron energy in the 0–14 eV energy range. The most intense negative fragment produced by DEA to isomers I–III is the dehydrogenated molecular anion [M–H] − , mainly formed at incident electron energies around 1 eV. The vertical and adiabatic electron affinities were evaluated at the B3LYP/6-31+G(d) level as the anion/neutral total energy difference. The same theoretical method was also used for evaluation of the thermodynamic energy thresholds for production of the negative fragments observed in the DEA spectra. The gas-phase DEAS data can provide support for biochemical reaction mechanisms in vivo

Dissociative electron attachment to vibrationally excited H2 molecules involving the 2Σg+ resonant Rydberg electronic state

International Nuclear Information System (INIS)

Celiberto, R.; Janev, R.K.; Wadehra, J.M.; Tennyson, J.

2012-01-01

Graphical abstract: Dissociative electron attachment cross sections as a function of the incident electron energy and for the initial vibration levels v i = 0–5, 10 of the H 2 molecule. Highlights: ► We calculated electron–hydrogen dissociative attachment cross sections and rates coefficients. ► Collision processes occurring through a resonant Rydberg state are considered. ► Cross sections and rates were obtained for vibrationally excited hydrogen molecules. ► The cross sections exhibit pronounced oscillatory structures. ► A comparison with the process involving the electron–hydrogen resonant ground state is discussed. - Abstract: Dissociative electron attachment cross sections (DEA) on vibrationally excited H 2 molecule taking place via the 2 Σ g + Rydberg-excited resonant state are studied using the local complex potential (LCP) model for resonant collisions. The cross sections are calculated for all initial vibrational levels (v i = 0–14) of the neutral molecule. In contrast to the previously noted dramatic increase in the DEA cross sections with increasing v i , when the process proceeds via the X 2 Σ u + shape resonance of H 2 , for the 2 Σ g + Rydberg resonance the cross sections increase only gradually up to v i = 3 and then decrease. Moreover, the cross sections for v i ⩾ 6 exhibit pronounced oscillatory structures. A discussion of the origin of the observed behavior of calculated cross sections is given. The DEA rate coefficients for all v i levels are also calculated in the 0.5–1000 eV temperature range.

Dissociative electron attachment to the gas-phase nucleobase hypoxanthine

Energy Technology Data Exchange (ETDEWEB)

Dawley, M. Michele [Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Tanzer, Katrin; Denifl, Stephan, E-mail: Stephan.Denifl@uibk.ac.at, E-mail: Sylwia.Ptasinska.1@nd.edu [Institut für Ionenphysik und Angewandte Physik, and Center for Molecular Biosciences Innsbruck (CMBI), Leopold-Franzens Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck (Austria); Carmichael, Ian [Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Ptasińska, Sylwia, E-mail: Stephan.Denifl@uibk.ac.at, E-mail: Sylwia.Ptasinska.1@nd.edu [Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

2015-06-07

We present high-resolution measurements of the dissociative electron attachment (DEA) to isolated gas-phase hypoxanthine (C{sub 5}H{sub 4}N{sub 4}O, Hyp), a tRNA purine base. The anion mass spectra and individual ion efficiency curves from Hyp were measured as a function of electron energy below 9 eV. The mass spectra at 1 and 6 eV exhibit the highest anion yields, indicating possible common precursor ions that decay into the detectable anionic fragments. The (Hyp − H) anion (C{sub 5}H{sub 3}N{sub 4}O{sup −}) exhibits a sharp resonant peak at 1 eV, which we tentatively assign to a dipole-bound state of the keto-N1H,N9H tautomer in which dehydrogenation occurs at either the N1 or N9 position based upon our quantum chemical computations (B3LYP/6-311+G(d,p) and U(MP2-aug-cc-pVDZ+)) and prior studies with adenine. This closed-shell dehydrogenated anion is the dominant fragment formed upon electron attachment, as with other nucleobases. Seven other anions were also observed including (Hyp − NH){sup −}, C{sub 4}H{sub 3}N{sub 4}{sup −}/C{sub 4}HN{sub 3}O{sup −}, C{sub 4}H{sub 2}N{sub 3}{sup −}, C{sub 3}NO{sup −}/HC(HCN)CN{sup −}, OCN{sup −}, CN{sup −}, and O{sup −}. Most of these anions exhibit broad but weak resonances between 4 and 8 eV similar to many analogous anions from adenine. The DEA to Hyp involves significant fragmentation, which is relevant to understanding radiation damage of biomolecules.

Excess electrons in simple fluids. IV. Real time behavior

International Nuclear Information System (INIS)

Nichols, A.L. III; Chandler, D.

1987-01-01

The polaron theory for an excess electron in liquids due to Chandler et al. [J. Chem. Phys. 81, 1975 (1984)] is extended to the real time domain by the method of analytic continuation. For the case of an adiabatic solvent, the theory predicts that the electron momentum correlations relax nonexponentially in time, and that this long time tail contributes to a diminuation of the electron mobility. However, for short ranged forces, a mean-field approximation employed in this application of the polaron theory leads to a decay that is one power of t -1 higher than the generally accepted result for the quantum Lorenz gas. Along with this analytical analysis, we present numerical solutions of the analytically continued equations for the case of an adiabatic hard sphere solvent. We find that at low solvent densities, the electronic states are relatively diffuse, and the absorption spectra is maximum at the zero frequency diffusive mode. In this density regime, the electron mobility is a decreasing function of temperature. At higher densities, the electron mobility drops precipitously and the spectra has its maxima at a nonzero frequency. Here, the mobility is an increasing function of temperature. Corresponding behaviors of the electron mean-square displacement correlation function are discussed. The high density behaviors are the dynamical consequences of ground state dominance or self-trapping where diffusion requires excitation to high energy extended states. These results augment our earlier work on the equilibrium or thermodynamic consequences of this theory

A practical approach to temperature effects in dissociative electron attachment cross sections using local complex potential theory

International Nuclear Information System (INIS)

Sugioka, Yuji; Takayanagi, Toshiyuki

2012-01-01

Highlights: ► Dissociative electron attachment cross sections for polyatomic molecules are calculated by a simple theoretical approach. ► Temperature effects can be reasonably reproduced with the present model. ► All the degrees-of-freedom are taken into account in the present dynamics approach. -- Abstract: We propose a practical computational scheme to obtain temperature dependence of dissociative electron attachment cross sections to polyatomic molecules within a local complex potential theory formalism. First we perform quantum path-integral molecular dynamics simulations on the potential energy surface for the neutral molecule in order to sample initial nuclear configurations as well as momenta. Classical trajectories are subsequently integrated on the potential energy surface for the anionic state and survival probabilities are simultaneously calculated along the obtained trajectories. We have applied this simple scheme to dissociative electron attachment processes to H 2 O and CF 3 Cl, for which several previous studies are available from both the experimental and theoretical sides.

A practical approach to temperature effects in dissociative electron attachment cross sections using local complex potential theory

Energy Technology Data Exchange (ETDEWEB)

Sugioka, Yuji [Department of Chemistry, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama 338-8570 (Japan); Takayanagi, Toshiyuki, E-mail: tako@mail.saitama-u.ac.jp [Department of Chemistry, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama 338-8570 (Japan)

2012-09-11

Highlights: Black-Right-Pointing-Pointer Dissociative electron attachment cross sections for polyatomic molecules are calculated by a simple theoretical approach. Black-Right-Pointing-Pointer Temperature effects can be reasonably reproduced with the present model. Black-Right-Pointing-Pointer All the degrees-of-freedom are taken into account in the present dynamics approach. -- Abstract: We propose a practical computational scheme to obtain temperature dependence of dissociative electron attachment cross sections to polyatomic molecules within a local complex potential theory formalism. First we perform quantum path-integral molecular dynamics simulations on the potential energy surface for the neutral molecule in order to sample initial nuclear configurations as well as momenta. Classical trajectories are subsequently integrated on the potential energy surface for the anionic state and survival probabilities are simultaneously calculated along the obtained trajectories. We have applied this simple scheme to dissociative electron attachment processes to H{sub 2}O and CF{sub 3}Cl, for which several previous studies are available from both the experimental and theoretical sides.

12 CFR 7.5004 - Sale of excess electronic capacity and by-products.

Science.gov (United States)

2010-01-01

... bank's needs for banking purposes include: (1) Data processing services; (2) Production and... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Sale of excess electronic capacity and by-products. 7.5004 Section 7.5004 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY...

Negative ion formation in dissociative electron attachment to selected halogen derivatives of propane

Science.gov (United States)

Barszczewska, W.; Kocísek, J.; Skalný, J.; Matejcík, V.; Matejcík, S.

2008-11-01

Dissociative electron attachment (DEA) to halogenated derivatives of propane: 1-bromo-3-chloropropane, 2-bromo-1-chloropropane, 3-bromo-1,1,1-trichloropropane and 1,3-dibromo-1,1-difluoropropane was studied in the gas phase at ambient temperature using a high resolution crossed electron/molecule beams technique. The negative ions formed via DEA reaction were identified using mass spectrometric technique and the anion yields were measured in the electron energy range from 0 to 10 eV. The absolute partial cross sections for DEA to the molecules were estimated using the relative flow technique.

Enhanced Electron Attachment to Highly-Excited Molecules and Its Applications in Pulsed Plasmas

International Nuclear Information System (INIS)

Ding, W.X.; Ma, C.Y.; McCorkle, D.L.; Pinnaduwage, L.A.

1999-01-01

Studies conducted over the past several years have shown that electron attachment to highly-excited states of molecules have extremely large cross sections. We will discuss the implications of this for pulsed discharges used for H - generation, material processing, and plasma remediation

Rate coefficients for dissociative attachment and resonant electron-impact dissociation involving vibrationally excited O{sub 2} molecules

Energy Technology Data Exchange (ETDEWEB)

Laporta, V. [Istituto di Metodologie Inorganiche e dei Plasmi, CNR, Bari, Italy and Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Celiberto, R. [Dipartimento di Ingegneria Civile, Ambientale, del Territorio, Edile e di Chimica, Politecnico di Bari, Italy and Istituto di Metodologie Inorganiche e dei Plasmi, CNR, Bari (Italy); Tennyson, J. [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)

2014-12-09

Rate coefficients for dissociative electron attachment and electron-impact dissociation processes, involving vibrationally excited molecular oxygen, are presented. Analytical fits of the calculated numerical data, useful in the applications, are also provided.

Implications of electron attachment to highly-excited states in pulsed-power discharges

International Nuclear Information System (INIS)

Pinnaduwage, L.A.; Univ. of Tennessee, Knoxville, TN

1997-01-01

The author points out the possible implications of electron attachment to highly-excited states of molecules in two pulsed power technologies. One involves the pulsed H 2 discharges used for the generation of H ion beams for magnetic fusion energy and particle accelerators. The other is the power modulated plasma discharges used for material processing

Lifetime of excess electrons in Cu–Zn–Sn–Se powders

Energy Technology Data Exchange (ETDEWEB)

Novikov, G. F., E-mail: ngf@icp.ac.ru; Gapanovich, M. V. [Russian Academy of Sciences, Institute of Problems in Chemical Physics (Russian Federation); Gremenok, V. F. [National Academy of Sciences of Belarus, Scientific and Practical Center for Materials Science (Belarus); Bocharov, K. V. [Russian Academy of Sciences, Institute of Problems in Chemical Physics (Russian Federation); Tsai, W.-T.; Jeng, Ming-Jer; Chang, Liann-Be [Chang Gung University, Department of Electronic Engineering (China)

2017-01-15

The method of time-resolved microwave photoconductivity at a frequency of 36 GHz in the range of temperatures of 200–300 K is used to study the kinetics of the annihilation of charge carriers in Cu–Zn–Sn–Se powders obtained by the solid-phase method of synthesis in cells. The lifetime of excess electrons at room temperature is found to be shorter than 5 ns. The activation energy for the process of recombination amounted to E{sub a} ~ 0.054 eV.

Anomalous electron-attachment properties of perfluoropropylene (1-C3F6) and their effect on the breakdown strength of this gas

International Nuclear Information System (INIS)

Hunter, S.R.; Christophorou, L.G.; McCorkle, D.L.; Sauers, I.; Ellis, H.W.; James, D.R.

1982-01-01

Electron attachment to perfluoropropylene (1-C 3 F 6 ) in 1-C 3 F 6 /buffer gas mixtures has been found to be anomalously dependent on both the 1-C 3 F 6 and buffer gas pressures, as well as on the gas temperature. We have found also that the uniform field breakdown strength of pure 1-C 3 F 6 is dependent on gas pressure but not on the gas temperature. A mass spectrometer study of the negative ions formed in a moderately high pressure corona discharge has been made, and the principal negative ions formed by electron attachment to 1-C 3 F 6 have been identified. Based on these studies, a reaction scheme for electron attachment to 1-C 3 F 6 is proposed which results in stable negative ion clusters but does not involve pre-existing dimers. Further, we propose that the observed pressure dependence in the breakdown strength of this gas is due to the large pressure dependence of the electron attachment process we observed

Pulse height measurements and electron attachment in drift chambers operated with Xe,CO2 mixtures

CERN Document Server

Andronic, A

2003-01-01

We present pulse height measurements in drift chambers operated with Xe,CO2 gas mixtures. We investigate the attachment of primary electrons on oxygen and SF6 contaminants in the detection gas. The measurements are compared with simulations of properties of drifting electrons. We present two methods to check the gas quality: gas chromatography and Fe55 pulse height measurements using monitor detectors.

Pulse height measurements and electron attachment in drift chambers operated with Xe,CO2 mixtures

International Nuclear Information System (INIS)

Andronic, A.; Appelshaeuser, H.; Blume, C.; Braun-Munzinger, P.; Bucher, D.; Busch, O.; Ramirez, A.C.A. Castillo; Catanescu, V.; Ciobanu, M.; Daues, H.; Devismes, A.; Emschermann, D.; Fateev, O.; Garabatos, C.; Herrmann, N.; Ivanov, M.; Mahmoud, T.; Peitzmann, T.; Petracek, V.; Petrovici, M.; Reygers, K.; Sann, H.; Santo, R.; Schicker, R.; Sedykh, S.; Shimansky, S.; Simon, R.S.; Smykov, L.; Soltveit, H.K.; Stachel, J.; Stelzer, H.; Tsiledakis, G.; Vulpescu, B.; Wessels, J.P.; Windelband, B.; Winkelmann, O.; Xu, C.; Zaudtke, O.; Zanevsky, Yu.; Yurevich, V.

2003-01-01

We present pulse height measurements in drift chambers operated with Xe,CO 2 gas mixtures. We investigate the attachment of primary electrons on oxygen and SF 6 contaminants in the detection gas. The measurements are compared with simulations of properties of drifting electrons. We present two methods to check the gas quality: gas chromatography and 55 Fe pulse height measurements using monitor detectors

Irreversible electron attachment--a key to DNA damage by solvated electrons in aqueous solution.

Science.gov (United States)

Westphal, K; Wiczk, J; Miloch, J; Kciuk, G; Bobrowski, K; Rak, J

2015-11-07

The TYT and TXT trimeric oligonucleotides, where X stands for a native nucleobase, T (thymine), C (cytosine), A (adenine), or G (guanine), and Y indicates a brominated analogue of the former, were irradiated with ionizing radiation generated by a (60)Co source in aqueous solutions containing Tris as a hydroxyl radical scavenger. In the past, these oligomers were bombarded with low energy electrons under an ultra-high vacuum and significant damage to TXT trimers was observed. However, in aqueous solution, hydrated electrons do not produce serious damage to TXT trimers although the employed radiation dose exceeded many times the doses used in radiotherapy. Thus, our studies demonstrate unequivocally that hydrated electrons, which are the major form of electrons generated during radiotherapy, are a negligible factor in damage to native DNA. It was also demonstrated that all the studied brominated nucleobases have a potential to sensitize DNA under hypoxic conditions. Strand breaks, abasic sites and the products of hydroxyl radical attachment to nucleobases have been identified by HPLC and LC-MS methods. Although all the bromonucleobases lead to DNA damage under the experimental conditions of the present work, bromopyrimidines seem to be the radiosensitizers of choice since they lead to more strand breaks than bromopurines.

A model explaining neutrino masses and the DAMPE cosmic ray electron excess

DEFF Research Database (Denmark)

Fan, Yi Zhong; Huang, Wei Chih; Spinrath, Martin

2018-01-01

We propose a flavored U(1)eμ neutrino mass and dark matter (DM) model to explain the recent DArk Matter Particle Explorer (DAMPE) data, which feature an excess on the cosmic ray electron plus positron flux around 1.4 TeV. Only the first two lepton generations of the Standard Model are charged under...... the new U(1)eμ gauge symmetry. A vector-like fermion ψ, which is our DM candidate, annihilates into e± and μ± via the new gauge boson Z′ exchange and accounts for the DAMPE excess. We have found that the data favors a ψ mass around 1.5 TeV and a Z′ mass around 2.6 TeV, which can potentially be probed...

Is there a link between childhood adversity, attachment style and Scotland’s excess mortality? Evidence, challenges and potential research

Directory of Open Access Journals (Sweden)

M. Smith

2016-07-01

Full Text Available Abstract Background Scotland has a persistently high mortality rate that is not solely due to the effects of socio-economic deprivation. This “excess” mortality is observed across the entire country, but is greatest in and around the post-industrial conurbation of West Central Scotland. Despite systematic investigation, the causes of the excess mortality remain the subject of ongoing debate. Discussion Attachment processes are a fundamental part of human development, and have a profound influence on adult personality and behaviour, especially in response to stressors. Many studies have also shown that childhood adversity is correlated with adult morbidity and mortality. The interplay between childhood adversity and attachment is complex and not fully elucidated, but will include socio-economic, intergenerational and psychological factors. Importantly, some adverse health outcomes for parents (such as problem substance use or suicide will simultaneously act as risk factors for their children. Data show that some forms of “household dysfunction” relating to childhood adversity are more prevalent in Scotland: such problems include parental problem substance use, rates of imprisonment, rates of suicide and rates of children being taken into care. However other measures of childhood or family wellbeing have not been found to be substantially different in Scotland compared to England. Summary We suggest in this paper that the role of childhood adversity and attachment experience merits further investigation as a plausible mechanism influencing health in Scotland. A model is proposed which sets out some of the interactions between the factors of interest, and we propose parameters for the types of study which would be required to evaluate the validity of the model.

Date Attachable Offline Electronic Cash Scheme

Directory of Open Access Journals (Sweden)

Chun-I Fan

2014-01-01

Full Text Available Electronic cash (e-cash is definitely one of the most popular research topics in the e-commerce field. It is very important that e-cash be able to hold the anonymity and accuracy in order to preserve the privacy and rights of customers. There are two types of e-cash in general, which are online e-cash and offline e-cash. Both systems have their own pros and cons and they can be used to construct various applications. In this paper, we pioneer to propose a provably secure and efficient offline e-cash scheme with date attachability based on the blind signature technique, where expiration date and deposit date can be embedded in an e-cash simultaneously. With the help of expiration date, the bank can manage the huge database much more easily against unlimited growth, and the deposit date cannot be forged so that users are able to calculate the amount of interests they can receive in the future correctly. Furthermore, we offer security analysis and formal proofs for all essential properties of offline e-cash, which are anonymity control, unforgeability, conditional-traceability, and no-swindling.

Date attachable offline electronic cash scheme.

Science.gov (United States)

Fan, Chun-I; Sun, Wei-Zhe; Hau, Hoi-Tung

2014-01-01

Electronic cash (e-cash) is definitely one of the most popular research topics in the e-commerce field. It is very important that e-cash be able to hold the anonymity and accuracy in order to preserve the privacy and rights of customers. There are two types of e-cash in general, which are online e-cash and offline e-cash. Both systems have their own pros and cons and they can be used to construct various applications. In this paper, we pioneer to propose a provably secure and efficient offline e-cash scheme with date attachability based on the blind signature technique, where expiration date and deposit date can be embedded in an e-cash simultaneously. With the help of expiration date, the bank can manage the huge database much more easily against unlimited growth, and the deposit date cannot be forged so that users are able to calculate the amount of interests they can receive in the future correctly. Furthermore, we offer security analysis and formal proofs for all essential properties of offline e-cash, which are anonymity control, unforgeability, conditional-traceability, and no-swindling.

Date Attachable Offline Electronic Cash Scheme

Science.gov (United States)

Sun, Wei-Zhe; Hau, Hoi-Tung

2014-01-01

Electronic cash (e-cash) is definitely one of the most popular research topics in the e-commerce field. It is very important that e-cash be able to hold the anonymity and accuracy in order to preserve the privacy and rights of customers. There are two types of e-cash in general, which are online e-cash and offline e-cash. Both systems have their own pros and cons and they can be used to construct various applications. In this paper, we pioneer to propose a provably secure and efficient offline e-cash scheme with date attachability based on the blind signature technique, where expiration date and deposit date can be embedded in an e-cash simultaneously. With the help of expiration date, the bank can manage the huge database much more easily against unlimited growth, and the deposit date cannot be forged so that users are able to calculate the amount of interests they can receive in the future correctly. Furthermore, we offer security analysis and formal proofs for all essential properties of offline e-cash, which are anonymity control, unforgeability, conditional-traceability, and no-swindling. PMID:24982931

Gonococcal attachment to eukaryotic cells

International Nuclear Information System (INIS)

James, J.F.; Lammel, C.J.; Draper, D.L.; Brown, D.A.; Sweet, R.L.; Brooks, G.F.

1983-01-01

The attachment of Neisseria gonorrhoeae to eukaryotic cells grown in tissue culture was analyzed by use of light and electron microscopy and by labeling of the bacteria with [ 3 H]- and [ 14 C]adenine. Isogenic piliated and nonpiliated N. gonorrhoeae from opaque and transparent colonies were studied. The results of light microscopy studies showed that the gonococci attached to cells of human origin, including Flow 2000, HeLa 229, and HEp 2. Studies using radiolabeled gonococci gave comparable results. Piliated N. gonorrhoeae usually attached in larger numbers than nonpiliated organisms, and those from opaque colonies attached more often than isogenic variants from transparent colonies. Day-to-day variation in rate of attachment was observed. Scanning electron microscopy studies showed the gonococcal attachment to be specific for microvilli of the host cells. It is concluded that more N. gonorrhoeae from opaque colonies, as compared with isogenic variants from transparent colonies, attach to eukaryotic cells grown in tissue culture

A model explaining neutrino masses and the DAMPE cosmic ray electron excess

Science.gov (United States)

Fan, Yi-Zhong; Huang, Wei-Chih; Spinrath, Martin; Tsai, Yue-Lin Sming; Yuan, Qiang

2018-06-01

We propose a flavored U(1)eμ neutrino mass and dark matter (DM) model to explain the recent DArk Matter Particle Explorer (DAMPE) data, which feature an excess on the cosmic ray electron plus positron flux around 1.4 TeV. Only the first two lepton generations of the Standard Model are charged under the new U(1)eμ gauge symmetry. A vector-like fermion ψ, which is our DM candidate, annihilates into e± and μ± via the new gauge boson Z‧ exchange and accounts for the DAMPE excess. We have found that the data favors a ψ mass around 1.5 TeV and a Z‧ mass around 2.6 TeV, which can potentially be probed by the next generation lepton colliders and DM direct detection experiments.

Excess electron is trapped in a large single molecular cage C60F60.

Science.gov (United States)

Wang, Yin-Feng; Li, Zhi-Ru; Wu, Di; Sun, Chia-Chung; Gu, Feng-Long

2010-01-15

A new kind of solvated electron systems, sphere-shaped e(-)@C60F60 (I(h)) and capsule-shaped e(-)@C60F60 (D6h), in contrast to the endohedral complex M@C60, is represented at the B3LYP/6-31G(d) + dBF (diffusive basis functions) density functional theory. It is proven, by examining the singly occupied molecular orbital (SOMO) and the spin density map of e(-)@C60F60, that the excess electron is indeed encapsulated inside the C60F60 cage. The shape of the electron cloud in SOMO matches with the shape of C60F60 cage. These cage-like single molecular solvated electrons have considerably large vertical electron detachment energies VDE of 4.95 (I(h)) and 4.67 eV (D6h) at B3LYP/6-31+G(3df) + dBF level compared to the VDE of 3.2 eV for an electron in bulk water (Coe et al., Int Rev Phys Chem 2001, 20, 33) and that of 3.66 eV for e(-)@C20F20 (Irikura, J Phys Chem A 2008, 112, 983), which shows their higher stability. The VDE of the sphere-shaped e(-)@C60F60 (I(h)) is greater than that of the capsule-shaped e(-)@C60F60 (D6h), indicating that the excess electron prefers to reside in the cage with the higher symmetry to form the more stable solvated electron. It is also noticed that the cage size [7.994 (I(h)), 5.714 and 9.978 A (D6h) in diameter] is much larger than that (2.826 A) of (H2O)20- dodecahedral cluster (Khan, Chem Phys Lett 2005, 401, 85). Copyright 2009 Wiley Periodicals, Inc.

Substrate dependence of electron-stimulated O - yields from dissociative electron attachment to physisorbed O2

Science.gov (United States)

Huels, M. A.; Parenteau, L.; Sanche, L.

1994-03-01

We present measurements of O- electron stimulated desorption yields obtained under identical experimental conditions from 0.15 monolayers (ML) of O2 deposited onto disordered substrates consisting of 4 ML of either Kr, Xe, C2H6, C2H4, N2O, CH3Cl, or H2O, all condensed on Pt (polycrystalline). The resulting O- yield functions, for incident electron energies below 20 eV, are compared to that obtained from the O2/Kr solid; this allows us to assess the order of magnitude effects of the local substrate environment on dissociative electron attachment (DEA) via the 2Πu and gas phase forbidden 2Σ+g,u resonances of O-2. We note that, in addition to electron energy losses in the substrate prior to DEA to O2 and post-dissociation interactions of the O- with the substrate molecules, charge or energy transfer from the O-2 transient anion to a substrate molecule, and capture of the incident electron into a dissociative anion resonance of the substrate molecule may contribute to a reduced O- yield from the physisorbed O2. In the case of O2 deposited on amorphous ice, we find that the O- signal from DEA to O2 is completely absent for electron energies below 14 eV; we attribute this to a complete quenching of the dissociative O-2(2Πu, 2Σ+) resonances by the adjacent water molecules.

Calculation on spectrum of direct DNA damage induced by low-energy electrons including dissociative electron attachment.

Science.gov (United States)

Liu, Wei; Tan, Zhenyu; Zhang, Liming; Champion, Christophe

2017-03-01

In this work, direct DNA damage induced by low-energy electrons (sub-keV) is simulated using a Monte Carlo method. The characteristics of the present simulation are to consider the new mechanism of DNA damage due to dissociative electron attachment (DEA) and to allow determining damage to specific bases (i.e., adenine, thymine, guanine, or cytosine). The electron track structure in liquid water is generated, based on the dielectric response model for describing electron inelastic scattering and on a free-parameter theoretical model and the NIST database for calculating electron elastic scattering. Ionization cross sections of DNA bases are used to generate base radicals, and available DEA cross sections of DNA components are applied for determining DNA-strand breaks and base damage induced by sub-ionization electrons. The electron elastic scattering from DNA components is simulated using cross sections from different theoretical calculations. The resulting yields of various strand breaks and base damage in cellular environment are given. Especially, the contributions of sub-ionization electrons to various strand breaks and base damage are quantitatively presented, and the correlation between complex clustered DNA damage and the corresponding damaged bases is explored. This work shows that the contribution of sub-ionization electrons to strand breaks is substantial, up to about 40-70%, and this contribution is mainly focused on single-strand break. In addition, the base damage induced by sub-ionization electrons contributes to about 20-40% of the total base damage, and there is an evident correlation between single-strand break and damaged base pair A-T.

Theoretical relaxation rates of dipole orientation around an excess electron in liquid alcohols

International Nuclear Information System (INIS)

Fueki, K.; Feng, D.F.; Kevan, L.

1975-01-01

A method was developed for calculation of relaxation times for dipole orientation in liquid alcohols induced by localized excess electrons. A microscopic model is used which utilizes quantities calculated from the Fueki, Feng, Kevan semicontinuum model of solvated electron energy levels. Given the semicontinuum model results, the relaxation times are calculated as functions of temperature with no adjustable parameters. Calculated results for methanol, ethanol and 1-propanol agree well with the limited experimental data available from Hunt, Baxendale and Wardman, and Thomas and Beck. The calculated results agree best for propanol and imply that the theoretical model is most applicable to larger molecule solvents. The impressive agreement between experiment and theory suggest that simple dipole orientation is the mechanism of rapid electron solvation in polar liquids. (auth)

Theoretical relaxation rates of dipole orientation around an excess electron in liquid alcohols

International Nuclear Information System (INIS)

Fueki, K.; Feng, D.F.; Kevan, L.

1975-01-01

A method is developed for calculation of relaxation times for dipole orientation in liquid alcohols induced by localized excess electrons. A microscopic model is used which utilizes quantities calculated from the Fueki, Feng, Kevan semicontinuum model of solvated electron energy levels. Given the semicontinuum model results, the relaxation times are calculated as functions of temperature with no adjustable parameters. Calculated results for methanol, ethanol and 1-propanol agree well with the limited experimental data available from Hunt, Baxendale and Wardman, and Thomas and Beck. The calculated results agree best for propanol and imply that the theoretical model is most applicable to larger molecule solvents. The impressive agreement between experiment and theory suggest that simple dipole orientation is the mechanism of rapid electron solvation in polar liquids. (author)

Pulse height measurements and electron attachment in drift chambers operated with Xe,CO{sub 2} mixtures

Energy Technology Data Exchange (ETDEWEB)

Andronic, A. E-mail: a.andronic@gsi.de; Appelshaeuser, H.; Blume, C.; Braun-Munzinger, P.; Bucher, D.; Busch, O.; Ramirez, A.C.A. Castillo; Catanescu, V.; Ciobanu, M.; Daues, H.; Devismes, A.; Emschermann, D.; Fateev, O.; Garabatos, C.; Herrmann, N.; Ivanov, M.; Mahmoud, T.; Peitzmann, T.; Petracek, V.; Petrovici, M.; Reygers, K.; Sann, H.; Santo, R.; Schicker, R.; Sedykh, S.; Shimansky, S.; Simon, R.S.; Smykov, L.; Soltveit, H.K.; Stachel, J.; Stelzer, H.; Tsiledakis, G.; Vulpescu, B.; Wessels, J.P.; Windelband, B.; Winkelmann, O.; Xu, C.; Zaudtke, O.; Zanevsky, Yu.; Yurevich, V

2003-02-11

We present pulse height measurements in drift chambers operated with Xe,CO{sub 2} gas mixtures. We investigate the attachment of primary electrons on oxygen and SF{sub 6} contaminants in the detection gas. The measurements are compared with simulations of properties of drifting electrons. We present two methods to check the gas quality: gas chromatography and {sup 55}Fe pulse height measurements using monitor detectors.

Cleavage of thymine N3-H bonds by low-energy electrons attached to base π* orbitals

International Nuclear Information System (INIS)

Theodore, Magali; Sobczyk, Monika; Simons, Jack

2006-01-01

In this work, we extend our earlier studies on single strand break (SSB) formation in DNA to consider the possibility of cleaving a thymine N 3 -H bond to generate a nitrogen-centered anion and a hydrogen radical which might proceed to induce further bond cleavages. In earlier studies, we considered SSBs induced by low-energy electrons that attach to DNA bases' π* orbitals or to phosphate P=O π* orbitals to cleave sugar-phosphate C-O bonds or base-sugar N 1 -C bonds. We also studied the effects of base π-stacking on the rates of such bond cleavages. To date, our results suggest that sugar-phosphate C-O bonds have the lowest barriers to cleavage, that attachment of electrons with energies below 2 eV most likely occurs at the base π* orbitals, that electrons with energy above 2 eV can also attach to phosphate P=O π* orbitals, and that base π stacking has a modest but slowing effect on the rates of SSB formation. However, we had not yet examined the possibility that base N 3 -H bonds could rupture subsequent to base π* orbital capture. In the present work, the latter possibility is considered and it is found that the barrier to cleavage of the N 3 -H bond in thymine is considerably higher than for cleaving sugar-phosphate C-O bonds, so our prediction that SSB formation is dominated by C-O bond cleavage remains intact

Electronic Communications Technologies and the Transition to College: Links to Parent-Child Attachment and Adjustment

Science.gov (United States)

Sarigiani, Pamela A.; Trumbell, Jill M.; Camarena, Phame M.

2013-01-01

Electronic communications technologies (ECTs) help college students and parents remain in contact. Because recent reports have emphasized a link between ECTs, helicopter parenting, and autonomy issues, this study focused on the significance of contact patterns for attachment and student adjustment. First-semester college students (199 female, 81…

Suppression of low-energy dissociative electron attachment in Fe(CO)5 upon clustering

Czech Academy of Sciences Publication Activity Database

Lengyel, Jozef; Papp, P.; Matejčík, Š.; Kočišek, Jaroslav; Fárník, Michal; Fedor, Juraj

2017-01-01

Roč. 8, č. 1 (2017), s. 2200-2207 ISSN 2190-4286 R&D Projects: GA ČR GA17-04844S; GA ČR(CZ) GA17-04068S; GA ČR GJ16-10995Y Grant - others:COST(XE) CM1301 Institutional support: RVO:61388955 Keywords : aggregation effects * FEBID * dissociative electron attachment Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 3.127, year: 2016

Kinematic study of O--ion formation from dissociative electron attachment to SO2

Science.gov (United States)

Jana, Irina; Nandi, Dhananjay

2018-04-01

We report a complete kinematic study of O--ion formation due to dissociative electron attachment to SO2 using the velocity slice imaging technique in the incident electron energy range over the resonances. Two resonances are observed at 5.2 and 7.5 eV, respectively. From the kinetic energy distribution, the two resonances are observed to have the same threshold energy, pointing to the fact that the two processes, giving rise to the two resonant peaks, have the same dissociation limit. From the angular distribution results we identified the involvement of an A1 and a combination of A1+B2 temporary negative-ion state(s) for the first and second resonances, respectively.

Reactions of metal-substituted myoglobins with excess electrons studied by pulse radiolysis and low-temperature gamma-radiolysis

International Nuclear Information System (INIS)

Miki, Hideho; Nakajima, Atushi; Ogasawara, Masaaki; Tamura, Mamoru

1990-01-01

Reactions of metal-substituted myoglobins with excess electrons in electron-pulse-irradiated aqueous solutions at room temperature and γ-irradiated aqueous matrices at 77 K were studied for the purpose of probing the functional role of heme iron. The rate constants for the reactions of various myoglobins with hydrated electrons were not much different from each other, and were close to those of diffusion-controlled reactions. In contrast, the reduction rates of myoglobins with dithionite depended markedly on the kind of central metals in the myoglobins. The difference was interpreted in terms of Marcus' theory for electron-transfer reactions. Effects of the 6-coordinate structure of the cobalt(III) species on the reaction with dithionite was also discussed. The steady-state optical-absorption measurements of γ-irradiated matrices containing cobaltimyoglobin at 77 K demonstrated the reduction of cobalt(III) species by excess electrons produced by the action of ionizing radiation. It was shown, by electron-spin resonance spectroscopy, that a 6-coordinated cobalt(II) species produced at 77 K transformed to a 5-coordinate one at higher temperatures, as reported previously. However, structural relaxation was not observed by optical spectroscopy either in the solutions or in the low-temperature matrices. It was concluded, therefore, that the intermediate 6-coordinate cobalt(II) species gave an optical absorption spectrum which was indistinguishable from that of the relaxed 5-coordinate cobalt(II) species. (author)

Electron attachment in F2 - Conclusive demonstration of nonresonant, s-wave coupling in the limit of zero electron energy

Science.gov (United States)

Chutjian, A.; Alajajian, S. H.

1987-01-01

Dissociative electron attachment to F2 has been observed in the energy range 0-140 meV, at a resolution of 6 meV (full width at half maximum). Results show conclusively a sharp, resolution-limited threshold behavior consistent with an s-wave cross section varying as sq rt of epsilon. Two accurate theoretical calculations predict only p-wave behavior varying as the sq rt of epsilon. Several nonadiabatic coupling effects leading to s-wave behavior are outlined.

Ultrafast electron dynamics at alkali/ice structures adsorbed on a metal surface

International Nuclear Information System (INIS)

Meyer, Michael

2011-01-01

The goal of this work is to study the interaction between excess electrons in water ice structures adsorbed on metal surfaces and other charged or neutral species, like alkali ions, or chemically reactive molecules, like chlorofluorocarbons (CFC), respectively. The excess electrons in the ice can interact with the ions directly or indirectly via the hydrogen bonded water molecules. In both cases the presence of the alkali influences the population, localization, and lifetime of electronic states of excess electrons in the ice adlayer. These properties are of great relevance when considering the highly reactive character of the excess electrons, which can mediate chemical reactions by dissociative electron attachment (DEA). The influence of alkali adsorption on electron solvation and transfer dynamics in ice structures is investigated for two types of adsorption configurations using femtosecond time-resolved two-photon photoelectron spectroscopy. In the first system alkali atoms are coadsorbed on top of a wetting amorphous ice film adsorbed on Cu(111). At temperatures between 60 and 100 K alkali adsorption leads to the formation of positively charged alkali ions at the ice/vacuum interface. The interaction between the alkali ions at the surface and the dipole moments of the surrounding water molecules results in a reorientation of the water molecules. As a consequence new electron trapping sites, i.e. at local potential minima, are formed. Photoinjection of excess electrons into these alkali-ion covered amorphous ice layers, results in the trapping of a solvated electron at an alkali-ion/water complex. In contrast to solvation in pure amorphous ice films, where the electrons are located in the bulk of the ice layer, solvated electrons at alkali-ion/water complexes are located at the ice/vacuum interface. They exhibit lifetimes of several picoseconds and show a fast energetic stabilization. With ongoing solvation, i.e. pump-probe time delay, the electron transfer is

Low-energy electron interaction with retusin extracted from Maackia amurensis: towards a molecular mechanism of the biological activity of flavonoids.

Science.gov (United States)

Pshenichnyuk, Stanislav A; Elkin, Yury N; Kulesh, Nadezda I; Lazneva, Eleonora F; Komolov, Alexei S

2015-07-14

The antioxidant isoflavone retusin efficiently attaches low-energy electrons in vacuo, generating fragment species via dissociative electron attachment (DEA), as has been shown by DEA spectroscopy. According to in silico results obtained by means of density functional theory, retusin is able to attach solvated electrons and could be decomposed under reductive conditions in vivo, for instance, near the mitochondrial electron transport chain, analogous to gas-phase DEA. The most intense decay channels of retusin temporary negative ions were found to be associated with the elimination of H atoms and H2 molecules. Doubly dehydrogenated fragment anions were predicted to possess a quinone structure. It is thought that molecular hydrogen, known for its selective antioxidant properties, can be efficiently generated via electron attachment to retusin in mitochondria and may be responsible for its antioxidant activity. The second abundant species, i.e., quinone bearing an excess negative charge, can serve as an electron carrier and can return the captured electron back to the respiration cycle. The number of OH substituents and their relative positions are crucial for the present molecular mechanism, which can explain the radical scavenging activity of polyphenolic compounds.

Origins of sharp cosmic-ray electron structures and the DAMPE excess

Science.gov (United States)

Huang, Xian-Jun; Wu, Yue-Liang; Zhang, Wei-Hong; Zhou, Yu-Feng

2018-05-01

Nearby sources may contribute to cosmic-ray electron (CRE) structures at high energies. Recently, the first DAMPE results on the CRE flux hinted at a narrow excess at energy ˜1.4 TeV . We show that in general a spectral structure with a narrow width appears in two scenarios. The first is spectrum broadening for the continuous sources with a δ -function-like injection spectrum. In this scenario, a finite width can develop after propagation through the Galaxy, which can reveal the distance of the source. Well-motivated sources include minispikes and subhalos formed by dark matter (DM) particles χs which annihilate directly into e+e- pairs. The second is phase-space shrinking for burstlike sources with a power-law-like injection spectrum. The spectrum after propagation can shrink at a cooling-related cutoff energy and form a sharp spectral peak. The peak can be more prominent due to the energy-dependent diffusion. In this scenario, the width of the excess constrains both the power index and the distance of the source. Possible such sources are pulsar wind nebulae (PWNe) and supernova remnants (SNRs). We analysis the DAMPE excess and find that the continuous DM sources should be fairly close within ˜0.3 kpc , and the annihilation cross sections are close to the thermal value. For the burstlike source, the narrow width of the excess suggests that the injection spectrum must be hard with power index significantly less than two, the distance is within ˜(3 - 4 ) kpc , and the age of the source is ˜0.16 Myr . In both scenarios, large anisotropies in the CRE flux are predicted. We identify possible candidates of minispike and PWN sources in the current Fermi-LAT 3FGL and ATNF catalog, respectively. The diffuse γ -rays from these sources can be well below the Galactic diffuse γ -ray backgrounds and less constrained by the Fermi-LAT data, if they are located at the low Galactic latitude regions.

Modelling fragmentations of amino-acids after resonant electron attachment: quantum evidence of possible direct -OH detachment

Energy Technology Data Exchange (ETDEWEB)

Panosetti, C.; Sebastianelli, F.; Gianturco, F.A. [Department of Chemistry and CNISM, University of Rome -La Sapienza-, Roma (Italy); Baccarelli, I. [CASPUR, Supercomputing Consortium for University and Research, Roma (Italy)

2010-10-15

We investigate some aspects of the radiation damage mechanisms in biomolecules, focusing on the modelling of resonant fragmentation caused by the attachment of low-energy electrons (LEEs) initially ejected by biological tissues when exposed to ionizing radiation. Scattering equations are formulated within a symmetry-adapted, single-center expansion of both continuum and bound electrons, and the interaction forces are obtained from a combination of ab initio calculations and a nonempirical model of exchange and correlation effects developed in our group. We present total elastic scattering cross-sections and resonance features obtained for the equilibrium geometries of glycine, alanine, proline and valine. Our results at those geometries of the target molecules are briefly shown to qualitatively explain some of the fragmentation patterns obtained in experiments. We further carry out a one-dimensional (1D) modeling for the dynamics of intramolecular energy transfers mediated by the vibrational activation of selected bonds: our calculations indicate that resonant electron attachment to glycine can trigger direct, dissociative evolution of the complex into (Gly-OH)- and -OH losses, while they also find that the same process does not occur via a direct, 1D dissociative path in the larger amino acids of the present study. (authors)

National data showed that delayed sleep in six-year-old children was associated with excessive use of electronic devices at 12 years.

Science.gov (United States)

Kato, Tsuguhiko; Yorifuji, Takashi; Yamakawa, Michiyo; Inoue, Sachiko

2018-01-31

Cross-sectional studies have shown associations between adolescent sleep problems and the use of electronic devices, such as mobile phones, but longitudinal studies remain scarce. We explored any association between delayed bedtimes at six years old and the excessive use of electronic devices at 12 years of age. Texting was a prime focus. We analysed 9607 adolescents who owned mobile phones in 2013 using the Japanese Longitudinal Survey of Newborns in the 21st Century, which started in 2001. The outcomes were daily excessive use of a mobile phone, television (TV) and video games. Delayed bedtime at the age of six years was associated with excessive texting at weekends. The adjusted odds ratios and 95% confidence intervals obtained from logistic regression analyses were 1.88 (1.14-3.10) for the 10-11 pm group and 1.98 (1.08-3.63) for the after 11 pm group, compared with the before 9 pm group. Later bedtimes were also associated with increased risks of excessive TV viewing and video game use. Our study indicated that six-year-olds who regularly stayed up late at night used electronic devices more frequently, or for longer, at the age of 12. Parents need to be more aware of links between sleep issues and electronic devices. ©2018 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Electron attachment to oxygen, ozone and other compounds of atmospheric relevance as studied with ultra-high energy resolution

International Nuclear Information System (INIS)

Maerk, T.D.; Matejcik, S.; Kiendler, A.; Cicman, P.; Senn, G.; Skalny, J.; Stampfli, P.; Illenberger, E.; Chu, Y.; Stamatovic, A.

1996-01-01

The processes of electron attachment to oxygen, ozone, ozone/oxygen cluster and oxygen cluster as well as other compounds of atmospheric relevance (CF 2 Cl 2 , CHCl 3 and CCl 3 Br) were studied with ultra-high energy resolution crossed beam technique

Novel Structures for the Excess Electron State of the Water Hexamer and the Interaction Forces Governing the Structures

International Nuclear Information System (INIS)

Lee, S.; Kim, J.; Lee, S.J.; Kim, K.S.

1997-01-01

The geometrical and electronic structures of partially hydrated electron systems, in particular, the water hexamer, which have been controversial for decades, have been clarified by an exhaustive search for possible low-lying energy structures. Several competing interaction forces governing the conformation have been examined for the first time. The low-lying energy structures are hybrid (or partially internal and partially surface) excess electron states. Our prediction is evidenced from excellent agreements with available experimental data. The vertical electron-detachment energies are mainly determined by the number of dangling H atoms (H d ) . copyright 1997 The American Physical Society

Effect of magnetic attachment with stress breaker on lateral stress to abutment tooth under overdenture.

Science.gov (United States)

Gonda, T; Ikebe, K; Ono, T; Nokubi, T

2004-10-01

Recently, a newly developed magnetic attachment with stress breaker was used in retentive components in overdentures. Excessive lateral stress has a more harmful effect on natural teeth than axial stress, and the magnetic attachment with stress breaker is expected to reduce lateral forces on abutment teeth and protect it teeth from excessive stress. However, the properties of this retainer have not yet been determined experimentally. This study compares the lateral forces on abutment teeth for three retainers under loading on the denture base in a model study. A mandibular simulation model is constructed to measure lateral stress. Three types of retentive devices are attached to the canine root. These devices include the conventional root coping, the conventional magnetic attachment and the new magnetic attachment with stress breaker. For each retentive device, load is generated on the occlusal table of the model overdenture, and the lateral stress on the canine root and the displacement of the overdenture measured. The magnetic attachment with stress breaker does not displace the denture and exhibits lower lateral stress in the canine root than conventional root coping and magnetic attachments.

Excess electron mobility in ethane. Density, temperature, and electric field effects

International Nuclear Information System (INIS)

Doeldissen, W.; Schmidt, W.F.; Bakale, G.

1980-01-01

The excess electron mobility in liquid ethane was measured under orthobaric conditions as a function of temperature and electric field strength up to the critical temperature at 305.33 K. The low field mobility was found to rise strongly with temperature and exhibits a maximum value of 44 cm 2 V -1 s -1 at 2 0 below the critical temperature. At temperatures above 260 K the electron drift velocity shows a sublinear field dependence at high values of the electric field strength. These observations lead to the supposition that in liquid ethane a transition from transport via localized states to transport in extended states occurs. Measurements were also performed in fluid ethane at densities from 2.4 to 12.45 mol L -1 and temperatures from 290 to 340 K. On isochores in the vicinity of the critical density, an increase of the low field mobility with temperature was observed. This effect was found to disappear both at low (rho = 2.4 mol L -1 ) and high densities (rho greater than or equal to 9.2 mol L -1 ). In this density range, a sublinear field dependence of the drift velocities at high field strengths was noted. The critical velocity associated with the appearance of hot electrons was observed to decrease with higher densities indicating a smaller fractional energy transfer in electron molecule collisions. A compilation of electron mobilities in gaseous and liquid ethane shows that, up to densitiesof rho = 9.5 mol L -1 , μ proportional to n -1 is fulfilled if temperature effects are ignored. At intermediate densities, 9 mol L -1 -1 , a density dependence of μ proportional to rho -5 is found followed by a stronger mobility decrease toward the triple point. Positive ion mobilities measured under orthobaric conditions followed Walden's rule

Electronic structure and transport on the surface of topological insulator attached to an electromagnetic superlattice

International Nuclear Information System (INIS)

Wang Haiyan; Chen Xiongwen; Zhou Xiaoying; Zhang Lebo; Zhou Guanghui

2012-01-01

We study the electronic structure and transport for Dirac electron on the surface of a three-dimensional (3D) topological insulator attached to an electromagnetic superlattice. It is found that, by means of the transfer-matrix method, the number of electronic tunneling channels for magnetic barriers in antiparallel alignment is larger than that in parallel alignment, which stems to the energy band structures. Interestingly, a remarkable semiconducting transport behavior appears in this system with a strong magnetic barrier due to low energy band nearly paralleling to the Fermi level. Consequently, there is only small incident angle transport in the higher energy region when the system is modulated mainly by the higher electric barriers. We further find that the spatial distribution of the spin polarization oscillates periodically in the incoming region, but it is almost in-plane with a fixed direction in the transmitting region. The results may provide a further understanding of the nature of 3D TI surface states, and may be useful in the design of topological insulator-based electronic devices such as collimating electron beam.

Modeling the Excess Cell Surface Stored in a Complex Morphology of Bleb-Like Protrusions.

Directory of Open Access Journals (Sweden)

Maryna Kapustina

2016-03-01

Full Text Available Cells transition from spread to rounded morphologies in diverse physiological contexts including mitosis and mesenchymal-to-amoeboid transitions. When these drastic shape changes occur rapidly, cell volume and surface area are approximately conserved. Consequently, the rounded cells are suddenly presented with a several-fold excess of cell surface whose area far exceeds that of a smooth sphere enclosing the cell volume. This excess is stored in a population of bleb-like protrusions (BLiPs, whose size distribution is shown by electron micrographs to be skewed. We introduce three complementary models of rounded cell morphologies with a prescribed excess surface area. A 2D Hamiltonian model provides a mechanistic description of how discrete attachment points between the cell surface and cortex together with surface bending energy can generate a morphology that satisfies a prescribed excess area and BLiP number density. A 3D random seed-and-growth model simulates efficient packing of BLiPs over a primary rounded shape, demonstrating a pathway for skewed BLiP size distributions that recapitulate 3D morphologies. Finally, a phase field model (2D and 3D posits energy-based constitutive laws for the cell membrane, nematic F-actin cortex, interior cytosol, and external aqueous medium. The cell surface is equipped with a spontaneous curvature function, a proxy for the cell surface-cortex couple, that is a priori unknown, which the model "learns" from the thin section transmission electron micrograph image (2D or the "seed and growth" model image (3D. Converged phase field simulations predict self-consistent amplitudes and spatial localization of pressure and stress throughout the cell for any posited stationary morphology target and cell compartment constitutive properties. The models form a general framework for future studies of cell morphological dynamics in a variety of biological contexts.

Benchmark calculations of excess electrons in water cluster cavities: balancing the addition of atom-centered diffuse functions versus floating diffuse functions.

Science.gov (United States)

Zhang, Changzhe; Bu, Yuxiang

2016-09-14

Diffuse functions have been proved to be especially crucial for the accurate characterization of excess electrons which are usually bound weakly in intermolecular zones far away from the nuclei. To examine the effects of diffuse functions on the nature of the cavity-shaped excess electrons in water cluster surroundings, both the HOMO and LUMO distributions, vertical detachment energies (VDEs) and visible absorption spectra of two selected (H2O)24(-) isomers are investigated in the present work. Two main types of diffuse functions are considered in calculations including the Pople-style atom-centered diffuse functions and the ghost-atom-based floating diffuse functions. It is found that augmentation of atom-centered diffuse functions contributes to a better description of the HOMO (corresponding to the VDE convergence), in agreement with previous studies, but also leads to unreasonable diffuse characters of the LUMO with significant red-shifts in the visible spectra, which is against the conventional point of view that the more the diffuse functions, the better the results. The issue of designing extra floating functions for excess electrons has also been systematically discussed, which indicates that the floating diffuse functions are necessary not only for reducing the computational cost but also for improving both the HOMO and LUMO accuracy. Thus, the basis sets with a combination of partial atom-centered diffuse functions and floating diffuse functions are recommended for a reliable description of the weakly bound electrons. This work presents an efficient way for characterizing the electronic properties of weakly bound electrons accurately by balancing the addition of atom-centered diffuse functions and floating diffuse functions and also by balancing the computational cost and accuracy of the calculated results, and thus is very useful in the relevant calculations of various solvated electron systems and weakly bound anionic systems.

Pressure effects on electron reactions and mobility in nonpolar liquids

International Nuclear Information System (INIS)

Holroyd, R.A.; Nishikawa, Masaru

2002-01-01

High pressure studies have elucidated the mechanisms of both electron reactions and electron transport in nonpolar liquids and provided information about the partial molar volumes of ions and electrons. The very large volume changes associated with electron attachment reactions have been explained as due to electrostriction by the ions, calculated with a continuum model, but modified to include the formation of a glassy shell of solvent molecules around the ion. The mobilities of electrons in cases where the electron is trapped can now be understood by comparing the trap cavity volume with the volume of electrostriction of the solvent around the cavity. In cases where the electron is quasi-free the compressibility dependent potential fluctuations are shown to be important. The isothermal compressibility is concluded to be the single most important parameter determining the behavior of excess electrons in liquids

Investigation of the Mechanism of Electron Capture and Electron Transfer Dissociation of Peptides with a Covalently Attached Free Radical Hydrogen Atom Scavenger.

Science.gov (United States)

Sohn, Chang Ho; Yin, Sheng; Peng, Ivory; Loo, Joseph A; Beauchamp, J L

2015-11-15

The mechanisms of electron capture and electron transfer dissociation (ECD and ETD) are investigated by covalently attaching a free-radical hydrogen atom scavenger to a peptide. The 2,2,6,6-tetramethylpiperidin-l-oxyl (TEMPO) radical was chosen as the scavenger due to its high hydrogen atom affinity (ca. 280 kJ/mol) and low electron affinity (ca. 0.45 ev), and was derivatized to the model peptide, FQX TEMPO EEQQQTEDELQDK. The X TEMPO residue represents a cysteinyl residue derivatized with an acetamido-TEMPO group. The acetamide group without TEMPO was also examined as a control. The gas phase proton affinity (882 kJ/mol) of TEMPO is similar to backbone amide carbonyls (889 kJ/mol), minimizing perturbation to internal solvation and sites of protonation of the derivatized peptides. Collision induced dissociation (CID) of the TEMPO tagged peptide dication generated stable odd-electron b and y type ions without indication of any TEMPO radical induced fragmentation initiated by hydrogen abstraction. The type and abundance of fragment ions observed in the CID spectra of the TEMPO and acetamide tagged peptides are very similar. However, ECD of the TEMPO labeled peptide dication yielded no backbone cleavage. We propose that a labile hydrogen atom in the charge reduced radical ions is scavenged by the TEMPO radical moiety, resulting in inhibition of N-C α backbone cleavage processes. Supplemental activation after electron attachment (ETcaD) and CID of the charge-reduced precursor ion generated by electron transfer of the TEMPO tagged peptide dication produced a series of b + H (b H ) and y + H (y H ) ions along with some c ions having suppressed intensities, consistent with stable O-H bond formation at the TEMPO group. In summary, the results indicate that ECD and ETD backbone cleavage processes are inhibited by scavenging of a labile hydrogen atom by the localized TEMPO radical moiety. This observation supports the conjecture that ECD and ETD processes involve long

Measurement of the electron attachment rates for SF6 and C7F14 at Te=0.2 eV in a magnetized Q machine plasma

International Nuclear Information System (INIS)

Merlino, Robert L.; Kim, Su-Hyun

2008-01-01

Electron attachment rates for SF 6 and C 7 F 14 were measured in a magnetized Q machine plasma at an electron temperature of 0.2±0.02 eV and with neutral gas pressures of P∼10 -4 Torr. The rate constants for attachment to SF 6 and C 7 F 14 were (7.6±2.0)x10 -8 and (2.2±0.9)x10 -7 cm 3 s -1 , respectively.

Contrast between the mechanisms for dissociative electron attachment to CH3SCN and CH3NCS

Science.gov (United States)

Miller, Thomas M.; Viggiano, Albert A.; Shuman, Nicholas S.

2018-05-01

The kinetics of thermal electron attachment to methyl thiocyanate (CH3SCN), methyl isothiocyanate (CH3NCS), and ethyl thiocyanate (C2H5SCN) were measured using flowing afterglow-Langmuir probe apparatuses at temperatures between 300 and 1000 K. CH3SCN and C2H5SCN undergo inefficient dissociative attachment to yield primarily SCN- at 300 K (k = 2 × 10-10 cm3 s-1), with increasing efficiency as temperature increases. The increase is well described by activation energies of 0.17 eV (CH3SCN) and 0.14 eV (C2H5SCN). CN- product is formed at product but at a rate at 300 K that is below our detection threshold (k differentiating the two mechanisms. The kinetic modeling reproduces the CH3NCS data only if dissociation through the transient anion is considered.

Electron reactions in model liquids and biological systems

International Nuclear Information System (INIS)

Bakale, G.; Gregg, E.C.

1982-01-01

Progress is reported in the following studies: (1) Field-dependent electron attachment; (2) Dependence of electron attachment rate on electron-acceptor dipole moment; (3) Electron attachment in i-octane/TMS mixtures; (4) Electron attachment/detachment equilibria; (5) Electron attachment to reversed micelles; (6) Electron attachment to chemical carcinogens; (7) Radiation-induced bacterial mutagenesis; and (8) Bacterial mutagenicity of nitrobenzene derivatives. 14 references

Intranasal administration of oxytocin modulates behavioral and amygdala responses to infant crying in females with insecure attachment representations.

Science.gov (United States)

Riem, Madelon M E; Bakermans-Kranenburg, Marian J; van IJzendoorn, Marinus H

2016-01-01

The current study examined the effects of oxytocin administration on the response to infant crying in individuals with secure or insecure attachment representations as assessed with the Adult Attachment Interview. We measured feelings of irritation and the use of excessive force as indicated by grip strength using a handgrip dynamometer during exposure to infant crying in 42 women without children who were administered intranasal oxytocin or a placebo. In addition, amygdala responses to infant crying and control sounds were measured with functional magnetic resonance imaging (fMRI). The effects of oxytocin on reactivity to crying were moderated by attachment security. Oxytocin decreased the use of excessive handgrip force and amygdala reactivity in response to crying in individuals with insecure attachment representations. Our findings indicate that insecure individuals, who show emotional, behavioral, and neural hyperreactivity to crying, benefit the most from intranasal oxytocin.

Non-iterative triple excitations in equation-of-motion coupled-cluster theory for electron attachment with applications to bound and temporary anions

Science.gov (United States)

Jagau, Thomas-C.

2018-01-01

The impact of residual electron correlation beyond the equation-of-motion coupled-cluster singles and doubles (EOM-CCSD) approximation on positions and widths of electronic resonances is investigated. To establish a method that accomplishes this task in an economical manner, several approaches proposed for the approximate treatment of triple excitations are reviewed with respect to their performance in the electron attachment (EA) variant of EOM-CC theory. The recently introduced EOM-CCSD(T)(a)* method [D. A. Matthews and J. F. Stanton, J. Chem. Phys. 145, 124102 (2016)], which includes non-iterative corrections to the reference and the target states, reliably reproduces vertical attachment energies from EOM-EA-CC calculations with single, double, and full triple excitations in contrast to schemes in which non-iterative corrections are applied only to the target states. Applications of EOM-EA-CCSD(T)(a)* augmented by a complex absorbing potential (CAP) to several temporary anions illustrate that shape resonances are well described by EOM-EA-CCSD, but that residual electron correlation often makes a non-negligible impact on their positions and widths. The positions of Feshbach resonances, on the other hand, are significantly improved when going from CAP-EOM-EA-CCSD to CAP-EOM-EA-CCSD(T)(a)*, but the correct energetic order of the relevant electronic states is still not achieved.

Electron-excited molecule interactions

International Nuclear Information System (INIS)

Christophorou, L.G.; Tennessee Univ., Knoxville, TN

1991-01-01

In this paper the limited but significant knowledge to date on electron scattering from vibrationally/rotationally excited molecules and electron scattering from and electron impact ionization of electronically excited molecules is briefly summarized and discussed. The profound effects of the internal energy content of a molecule on its electron attachment properties are highlighted focusing in particular on electron attachment to vibrationally/rotationally and to electronically excited molecules. The limited knowledge to date on electron-excited molecule interactions clearly shows that the cross sections for certain electron-molecule collision processes can be very different from those involving ground state molecules. For example, optically enhanced electron attachment studies have shown that electron attachment to electronically excited molecules can occur with cross sections 10 6 to 10 7 times larger compared to ground state molecules. The study of electron-excited molecule interactions offers many experimental and theoretical challenges and opportunities and is both of fundamental and technological significance. 54 refs., 15 figs

Dissociative electron attachment negative ion mass spectrometry: a chlorine-specific detector for gas chromatography

Science.gov (United States)

Curtis, Jonathan M.; Boyd, Robert K.

1997-11-01

This work describes the application of negative ion chemical ionization, optimized for dissociative electron attachment (DEA), to location of unknown trace chlorinated compounds in complex gas chromatograms by selected ion recording (SIR) of m / z 35 and 37. The DEA-SIR technique is compared with other GC detectors, including the electron capture detector, electrolytic conductivity detector, the atomic emission detector and the chemical reaction interface mass spectrometry method, with respect to selectivity for chlorine, sensitivity, linear dynamic range, and general robustness and ease of use. When applied to quantitative analysis of target analytes such as polychlorobiphenyls, the DEA-SIR method has potential problems arising from the possibility of suppression effects due to abundant co-eluting components, and possible alleviating measures are discussed. In addition to these practical investigations, literature information on the fundamental physical and chemical phenomena underlying the DEA process is summarized in order to guide future work on extension to other compound types and on general improvements to the technique.

Transport of excess electrons in dense dielectric fluids. Phenomenological interpretation and application to a one-dimensional argon fluid

International Nuclear Information System (INIS)

Leycuras, A.; Larour, J.

1978-01-01

The main results about the drift velocities of excess electrons in dense argon are summarized. The weaknesses of the available theories are mainly due to poor information concerning the electron-atom potential during an atom-atom collision. The drift velocities, as a function of the applied electric field present the following features at high fields: the drift velocity reaches a limit that is at most one order of magnitude larger than the sound velocity at the same density. These remarks and the attractive nature of the electron-atom potential suggest a transport model, the collisional transfer model analog to the one applied to the determination of the sound velocity. Drift velocities obtained with this model applied to a one-dimensional molecular dynamics simulation are presented [fr

Intranasal administration of oxytocin modulates behavioral and amygdala responses to infant crying in females with insecure attachment representations

NARCIS (Netherlands)

Hendricx-Riem, M.M.E.; Bakermans-Kranenburg, Marian J.; van IJzendoorn, Marinus H.

2016-01-01

The current study examined the effects of oxytocin administration on the response to infant crying in individuals with secure or insecure attachment representations as assessed with the Adult Attachment Interview. We measured feelings of irritation and the use of excessive force as indicated by grip

Excess energy partitioning between electrons departing at 0o and 180o in the ionization of helium near threshold

International Nuclear Information System (INIS)

Asmis, K.R.; Allan, M.

1997-01-01

Partitioning of excess energy between electrons departing at 0 o and 180 o after electron-impact ionization of helium has been measured. A recently developed scheme, using a magnetically collimated electron-impact spectrometer, pulsed incident electron beam and time-of-flight detection was used to detect the electrons departing in the forward and backward directions. The ratios of the forward and backward doubly differential cross-sections (DDCS) for an incident electron energy 3 eV above threshold and secondary electron energies of 0.7, 1.5 and 2.9 eV were measured. The relative DDCS at 0 o and 180 o are also presented as a function of the secondary electron energy, for incident electron energies 3 and 5 eV above threshold. Our measurements show that the distribution of the secondary electrons is, in contrast to electrons detected at 90 o , not flat for electrons departing at 0 o and 180 o at the present low primary energies. The yield of the faster secondary electrons is forward peaked, the yield of the slower secondary electrons is backward peaked. The sum of the 0 o and 180 o DDCS is, however, flat within the experimental uncertainty limits. (Author)

Direction-specific interactions control crystal growth by oriented attachment

DEFF Research Database (Denmark)

Li, Dongsheng; Nielsen, Michael H; Lee, Jonathan R.I.

2012-01-01

The oriented attachment of molecular clusters and nanoparticles in solution is now recognized as an important mechanism of crystal growth in many materials, yet the alignment process and attachment mechanism have not been established. We performed high-resolution transmission electron microscopy ...

Ab initio calculation of the cross sections for electron impact vibrational excitation of CO via the {sup 2}Π shape resonance

Energy Technology Data Exchange (ETDEWEB)

Falcetta, Michael F., E-mail: mffalcetta@gcc.edu; Fair, Mark C.; Tharnish, Emily M.; Williams, Lorna M.; Hayes, Nathan J. [Department of Chemistry, Grove City College, Grove City, Pennsylvania 16127 (United States); Jordan, Kenneth D. [Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)

2016-03-14

The stabilization method is used to calculate the complex potential energy curve of the {sup 2}Π state of CO{sup −} as a function of bond length, with the refinement that separate potentials are determined for p-wave and d-wave attachment and detachment of the excess electron. Using the resulting complex potentials, absolute vibrational excitation cross sections are calculated as a function of electron energy and scattering angle. The calculated cross sections agree well with experiment.

Effect of excess superthermal hot electrons on finite amplitude ion-acoustic solitons and supersolitons in a magnetized auroral plasma

Energy Technology Data Exchange (ETDEWEB)

Rufai, O. R., E-mail: rrufai@csir.co.za [Council for Scientific and Industrial Research, Pretoria (South Africa); Bharuthram, R., E-mail: rbharuthram@uwc.ac.za [University of the Western Cape, Bellville (South Africa); Singh, S. V., E-mail: satyavir@iigs.iigm.res.in; Lakhina, G. S., E-mail: lakhina@iigs.iigm.res.in [Indian Institute of Geomagnetism, New Panvel (W), Navi, Mumbai-410218 (India)

2015-10-15

The effect of excess superthermal electrons is investigated on finite amplitude nonlinear ion-acoustic waves in a magnetized auroral plasma. The plasma model consists of a cold ion fluid, Boltzmann distribution of cool electrons, and kappa distributed hot electron species. The model predicts the evolution of negative potential solitons and supersolitons at subsonic Mach numbers region, whereas, in the case of Cairn's nonthermal distribution model for the hot electron species studied earlier, they can exist both in the subsonic and supersonic Mach number regimes. For the dayside auroral parameters, the model generates the super-acoustic electric field amplitude, speed, width, and pulse duration of about 18 mV/m, 25.4 km/s, 663 m, and 26 ms, respectively, which is in the range of the Viking spacecraft measurements.

God attachment, mother attachment, and father attachment in early and middle adolescence.

Science.gov (United States)

Sim, Tick Ngee; Yow, Amanda Shixian

2011-06-01

The present study examined the interplay of attachment to God, attachment to mother, and attachment to father with respect to adjustment (hope, self-esteem, depression) for 130 early and 106 middle adolescents in Singapore. Results showed that the parental attachments were generally linked (in expected directions) to adjustment. God attachment, however, had unique results. At the bivariate level, God attachment was only linked to early adolescents' self-esteem. When considered together with parental attachments (including interactions), God attachment did not emerge as the key moderator in attachment interactions and yielded some unexpected results (e.g., being positively linked to depression). These results are discussed viz-a-viz the secure base and safe haven functions that God and parental attachments may play during adolescence.

Electron beam induced deposition of silacyclohexane and dichlorosilacyclohexane: the role of dissociative ionization and dissociative electron attachment in the deposition process

Directory of Open Access Journals (Sweden)

Ragesh Kumar T P

2017-11-01

Full Text Available We present first experiments on electron beam induced deposition of silacyclohexane (SCH and dichlorosilacyclohexane (DCSCH under a focused high-energy electron beam (FEBID. We compare the deposition dynamics observed when growing pillars of high aspect ratio from these compounds and we compare the proximity effect observed for these compounds. The two precursors show similar behaviour with regards to fragmentation through dissociative ionization in the gas phase under single-collision conditions. However, while DCSCH shows appreciable cross sections with regards to dissociative electron attachment, SCH is inert with respect to this process. We discuss our deposition experiments in context of the efficiency of these different electron-induced fragmentation processes. With regards to the deposition dynamics, we observe a substantially faster growth from DCSCH and a higher saturation diameter when growing pillars with high aspect ratio. However, both compounds show similar behaviour with regards to the proximity effect. With regards to the composition of the deposits, we observe that the C/Si ratio is similar for both compounds and in both cases close to the initial molecular stoichiometry. The oxygen content in the DCSCH deposits is about double that of the SCH deposits. Only marginal chlorine is observed in the deposits of from DCSCH. We discuss these observations in context of potential approaches for Si deposition.

A nonlocal, ab initio model of dissociative electron attachment and vibrational excitation of NO

International Nuclear Information System (INIS)

Trevisan, Cynthia S.; Houfek, Karel; Zhang, Zhiyong; Orel, Ann E.; McCurdy, C. William; Rescigno, Thomas N.

2005-01-01

We present the results of an ab initio study of elastic scattering and vibrational excitation of NO by electron impact in the loW--energy (0-2 eV) region where the cross sections are dominated by resonance contributions. The 3Sigma-, 1Delta and 1Sigma+ NO- resonance lifetimes are taken from our earlier study [Phys. Rev. A 69, 062711 (2004)], but the resonance energies used here are obtained from new configuration-interaction studies. Here we employ a more elaborate nonlocal treatment of the nuclear dynamics, which is found to remedy the principal deficiencies of the local complex potential model we employed in our earlier study, and gives cross sections in better agreement with the most recent experiments. We also present cross sections for dissociative electron attachment to NO leading to groundstate products. The calculations show that, while the peak cross sections starting from NO in its ground vibrational state are very small, the cross sections are extremely sensitive to vibrational excitation of the target and should be readily observable for target NO molecules excited to v = 10 and above

Phenotypes of non-attached Pseudomonas aeruginosa aggregates resemble surface attached biofilm.

Directory of Open Access Journals (Sweden)

Morten Alhede

Full Text Available For a chronic infection to be established, bacteria must be able to cope with hostile conditions such as low iron levels, oxidative stress, and clearance by the host defense, as well as antibiotic treatment. It is generally accepted that biofilm formation facilitates tolerance to these adverse conditions. However, microscopic investigations of samples isolated from sites of chronic infections seem to suggest that some bacteria do not need to be attached to surfaces in order to establish chronic infections. In this study we employed scanning electron microscopy, confocal laser scanning microscopy, RT-PCR as well as traditional culturing techniques to study the properties of Pseudomonas aeruginosa aggregates. We found that non-attached aggregates from stationary-phase cultures have comparable growth rates to surface attached biofilms. The growth rate estimations indicated that, independently of age, both aggregates and flow-cell biofilm had the same slow growth rate as a stationary phase shaking cultures. Internal structures of the aggregates matrix components and their capacity to survive otherwise lethal treatments with antibiotics (referred to as tolerance and resistance to phagocytes were also found to be strikingly similar to flow-cell biofilms. Our data indicate that the tolerance of both biofilms and non-attached aggregates towards antibiotics is reversible by physical disruption. We provide evidence that the antibiotic tolerance is likely to be dependent on both the physiological states of the aggregates and particular matrix components. Bacterial surface-attachment and subsequent biofilm formation are considered hallmarks of the capacity of microbes to cause persistent infections. We have observed non-attached aggregates in the lungs of cystic fibrosis patients; otitis media; soft tissue fillers and non-healing wounds, and we propose that aggregated cells exhibit enhanced survival in the hostile host environment, compared with non

Adult Attachment Ratings (AAR): an item response theory analysis.

Science.gov (United States)

Pilkonis, Paul A; Kim, Yookyung; Yu, Lan; Morse, Jennifer Q

2014-01-01

The Adult Attachment Ratings (AAR) include 3 scales for anxious, ambivalent attachment (excessive dependency, interpersonal ambivalence, and compulsive care-giving), 3 for avoidant attachment (rigid self-control, defensive separation, and emotional detachment), and 1 for secure attachment. The scales include items (ranging from 6-16 in their original form) scored by raters using a 3-point format (0 = absent, 1 = present, and 2 = strongly present) and summed to produce a total score. Item response theory (IRT) analyses were conducted with data from 414 participants recruited from psychiatric outpatient, medical, and community settings to identify the most informative items from each scale. The IRT results allowed us to shorten the scales to 5-item versions that are more precise and easier to rate because of their brevity. In general, the effective range of measurement for the scales was 0 to +2 SDs for each of the attachment constructs; that is, from average to high levels of attachment problems. Evidence for convergent and discriminant validity of the scales was investigated by comparing them with the Experiences of Close Relationships-Revised (ECR-R) scale and the Kobak Attachment Q-sort. The best consensus among self-reports on the ECR-R, informant ratings on the ECR-R, and expert judgments on the Q-sort and the AAR emerged for anxious, ambivalent attachment. Given the good psychometric characteristics of the scale for secure attachment, however, this measure alone might provide a simple alternative to more elaborate procedures for some measurement purposes. Conversion tables are provided for the 7 scales to facilitate transformation from raw scores to IRT-calibrated (theta) scores.

The assignment of dissociative electron attachment bands in compounds containing hydroxyl and amino groups

International Nuclear Information System (INIS)

Skalicky, Tomas; Allan, Michael

2004-01-01

Dissociative electron attachment (DEA) spectra were recorded for methanol, phenol, diethylamine, tetramethylhydrazine, piperazine, pyrrole and N,N-dimethylaniline. Comparison with He I photoelectron spectra permitted the assignment of virtually all DEA bands in the saturated compounds to core excited Feshbach resonances with double occupation of Rydberg-like orbitals and various Koopmans' states of the positive ion as a core. These resonances shift to lower energies with alkyl substitution, in contrast to the shape resonances, and are found at surprisingly low energies in the amines. The DEA spectra in the unsaturated compounds show no or only weak evidence for the Rydberg-type Feshbach resonances. It is proposed that DEA in saturated polyatomic molecules containing hydroxyl and amino groups is in general dominated by this type of resonance

Equation-of-motion coupled cluster method for high spin double electron attachment calculations

Energy Technology Data Exchange (ETDEWEB)

Musiał, Monika, E-mail: musial@ich.us.edu.pl; Lupa, Łukasz; Kucharski, Stanisław A. [Institute of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice (Poland)

2014-03-21

The new formulation of the equation-of-motion (EOM) coupled cluster (CC) approach applicable to the calculations of the double electron attachment (DEA) states for the high spin components is proposed. The new EOM equations are derived for the high spin triplet and quintet states. In both cases the new equations are easier to solve but the substantial simplification is observed in the case of quintets. Out of 21 diagrammatic terms contributing to the standard DEA-EOM-CCSDT equations for the R{sub 2} and R{sub 3} amplitudes only four terms survive contributing to the R{sub 3} part. The implemented method has been applied to the calculations of the excited states (singlets, triplets, and quintets) energies of the carbon and silicon atoms and potential energy curves for selected states of the Na{sub 2} (triplets) and B{sub 2} (quintets) molecules.

The Structural Model in Parenting Style, Attachment Style, Self-regulation and Self-esteem for Smartphone Addiction

Directory of Open Access Journals (Sweden)

Kwan Hoi Ching

2017-08-01

Full Text Available Excessive smartphone usage has become a highly controversial and substantial worldwide issue. This paper explores the complexities and challenges of smartphone addiction with a particular focus on parenting styles, attachment, and self-regulation. Convenience sampling was used to gather data from 211 university students in Hong Kong (138 females/74 males through their responses to four questionnaires. One structural equation model was formed successfully which indicated that parenting style (authoritative or permissive could be a reasonable predictor of attachment style (secure or dismissive and self-regulation (impulse control or goal setting for smartphone addictions (positive anticipation, withdrawal, cyberspace relationship or overuse. Parenting style was a positive correlate to predict attachment, while the attachment positive correlated to predict self-regulation. Self-regulation was a negative correlate to smartphone addiction. It was revealed that a positive parenting style and positive attachment style could form a significant model with self-regulation and smartphone addiction. Furthermore, secure attachment had higher mediation effect, while impulse control and goal setting behavior had a fair mediation power over influencing addiction tendency. This model helped explore the relationships between smartphone addiction and other constructs in educational psychology. Based on findings, educators can gain insights into how parenting and self-regulation can influence the tendency towards excessive smartphone usage. More educational programs which aim at promoting adequate parenting skills, motivating children through self-regulation and goal setting, is proposed through this study.

NAFFS: network attached flash file system for cloud storage on portable consumer electronics

Science.gov (United States)

Han, Lin; Huang, Hao; Xie, Changsheng

Cloud storage technology has become a research hotspot in recent years, while the existing cloud storage services are mainly designed for data storage needs with stable high speed Internet connection. Mobile Internet connections are often unstable and the speed is relatively low. These native features of mobile Internet limit the use of cloud storage in portable consumer electronics. The Network Attached Flash File System (NAFFS) presented the idea of taking the portable device built-in NAND flash memory as the front-end cache of virtualized cloud storage device. Modern portable devices with Internet connection have built-in more than 1GB NAND Flash, which is quite enough for daily data storage. The data transfer rate of NAND flash device is much higher than mobile Internet connections[1], and its non-volatile feature makes it very suitable as the cache device of Internet cloud storage on portable device, which often have unstable power supply and intermittent Internet connection. In the present work, NAFFS is evaluated with several benchmarks, and its performance is compared with traditional network attached file systems, such as NFS. Our evaluation results indicate that the NAFFS achieves an average accessing speed of 3.38MB/s, which is about 3 times faster than directly accessing cloud storage by mobile Internet connection， and offers a more stable interface than that of directly using cloud storage API. Unstable Internet connection and sudden power off condition are tolerable, and no data in cache will be lost in such situation.

Modulation instability and dissipative rogue waves in ion-beam plasma: Roles of ionization, recombination, and electron attachment

Energy Technology Data Exchange (ETDEWEB)

Guo, Shimin, E-mail: gsm861@126.com; Mei, Liquan, E-mail: lqmei@mail.xjtu.edu.cn [School of Mathematics and Statistics, Xi' an Jiaotong University, Xi' an 710049 (China)

2014-11-15

The amplitude modulation of ion-acoustic waves is investigated in an unmagnetized plasma containing positive ions, negative ions, and electrons obeying a kappa-type distribution that is penetrated by a positive ion beam. By considering dissipative mechanisms, including ionization, negative-positive ion recombination, and electron attachment, we introduce a comprehensive model for the plasma with the effects of sources and sinks. Via reductive perturbation theory, the modified nonlinear Schrödinger equation with a dissipative term is derived to govern the dynamics of the modulated waves. The effect of the plasma parameters on the modulation instability criterion for the modified nonlinear Schrödinger equation is numerically investigated in detail. Within the unstable region, first- and second-order dissipative ion-acoustic rogue waves are present. The effect of the plasma parameters on the characteristics of the dissipative rogue waves is also discussed.

Kinetic-energy distributions of O- produced by dissociative electron attachment to physisorbed O2

International Nuclear Information System (INIS)

Huels, M.A.; Parenteau, L.; Michaud, M.; Sanche, L.

1995-01-01

We report measurements of the kinetic energy (E k ) distributions of O - produced by low-energy electron impact (5.5--19.5 eV) on disordered multilayers of O 2 physisorbed on a polycrystalline Pt substrate. The results confirm that dissociative electron attachment (DEA) proceeds via the formation of the 2 Π u , 2 Σ g + (I), and 2 Σ x + (II) (x=g and/or u) states of O 2 -* . We also find evidence for an additional resonance, namely the 2 Σ u + (I), positioned at about 10 eV above the neutral ground state in the Franck-Condon region, and dissociating into O - +O( 3 P). The measurements suggest that the autodetachment lifetimes of the 2 Σ u + (I) and 2 Σ g + (II) states may be longer than previously suggested. It is also observed that the effects of electron energy loss (EEL) in the solid prior to DEA, O - scattering in the solid after dissociation, and the charge-induced polarization energy of the solid, broaden the E k distributions, shift them to lower anion energies, and result in additional structure in them. The effects of EEL on the desorption dynamics of O - are estimated from high-resolution electron-energy-loss spectra and excitation functions for losses in the vicinity of the Schumann-Runge continuum of the physisorbed O 2 molecules. We find indications for an enhancement of the optically forbidden X 3 Σ g - →A 3 Σ u + transition, and observe that the gas-phase Rydberg bands, for energy losses above 7 eV, are not distinguishable in the condensed phase

Electron attachment properties of c-C4F8O\

Czech Academy of Sciences Publication Activity Database

Chachereau, A.; Fedor, Juraj; Janečková, R.; Kočišek, Jaroslav; Rabie, M.; Franck, C. M.

2016-01-01

Roč. 49, č. 37 (2016), 375201 ISSN 0022-3727 Institutional support: RVO:61388955 Keywords : C4F8O * octafluorotetrahydrofuran * attachment cross section Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.588, year: 2016

Towards explaining excess CO2 production in wetlands - the roles of solid and dissolved organic matter as electron acceptors and of substrate quality

Science.gov (United States)

Knorr, Klaus-Holger; Gao, Chuanyu; Agethen, Svenja; Sander, Michael

2017-04-01

To understand carbon storage in water logged, anaerobic peatlands, factors controlling mineralization have been studied for decades. Temperature, substrate quality, water table position and the availability of electron acceptors for oxidation of organic carbon have been identified as major factors. However, many studies reported an excess carbon dioxide (CO2) production over methane (CH4) that cannot be explained by available electron acceptors, and peat soils did not reach strictly methanogenic conditions (i.e., a stoichiometric formation ratio of 1:1 of CO2 to CH4). It has been hypothesized that peat organic matter (OM) provides a previously unrecognized electron acceptor for microbial respiration, elevating CO2 to CH4 ratios. Microbial reduction of dissolved OM has been shown in the mid 90's, but only recently mediated electrochemical techniques opened the possibility to access stocks and changes in electron accepting capacities (EAC) of OM in dissolved and solid form. While it was shown that the EAC of OM follows redox cycles of microbial reduction and O2 reoxidation, changes in the EAC of OM were so far not related quantitatively to CO2 production. We therefore tested if CO2 production in anoxic peat incubations is balanced by the consumption of electron acceptors if EAC of OM is included. We set up anoxic incubations with peat and monitored production of CO2 and CH4, and changes in EAC of OM in the dissolved and solid phase over time. Interestingly, in all incubations, the EAC of dissolved OM was poorly related to CO2 and CH4 production. Instead, dissolved OM was rapidly reduced at the onset of the incubations and thereafter remained in reduced form. In contrast, the decrease in the EAC of particulate (i.e. non-dissolved) OM was closely linked to the observed production of non-methanogenic CO2. Thereby, the total EAC of the solid OM pool by far exceeded the EAC of the dissolved OM pool. Over the course of eight week incubations, measured decreases in the EAC

Metastable He2- ions formed by two-electron attachment to the excited He2+ Σg+ (1σg22σg1) core

International Nuclear Information System (INIS)

Adamowicz, L.; Pluta, T.

1991-01-01

Four metastable states (1 4 Π u , 2 4 Π u , 4 Φ u , and 4 I u ), resulting from two-electron attachments to the excited He 2 + core ( 2 Σ g + ), are characterized using the numerical Hartree-Fock method. It is determined that such metastable states are formed when both valence electrons are placed into equally diffused orbitals, which have bonding charter, and whose angular momentum quantum numbers do not differ by more than 1

Electron attachment to the phthalide molecule

Energy Technology Data Exchange (ETDEWEB)

Asfandiarov, N. L. [Institute of Molecule and Crystal Physics, Ufa Research Centre, Russian Academy of Sciences, Prospect Oktyabrya 151, 450075 Ufa (Russian Federation); Bashkir State Pedagogical University, Oktyabrskoy Revolutsii St., 3a, 450000 Ufa (Russian Federation); Pshenichnyuk, S. A. [Institute of Molecule and Crystal Physics, Ufa Research Centre, Russian Academy of Sciences, Prospect Oktyabrya 151, 450075 Ufa (Russian Federation); St.-Petersburg State University, Uljanovskaja, 1, 198504 St.-Petersburg (Russian Federation); Vorob’ev, A. S.; Nafikova, E. P. [Institute of Molecule and Crystal Physics, Ufa Research Centre, Russian Academy of Sciences, Prospect Oktyabrya 151, 450075 Ufa (Russian Federation); Lachinov, A. N. [Bashkir State Pedagogical University, Oktyabrskoy Revolutsii St., 3a, 450000 Ufa (Russian Federation); Kraikin, V. A. [Institute of Organic Chemistry, Ufa Research Centre, Russian Academy of Sciences, Prospect Oktyabrya 59, 450075 Ufa (Russian Federation); Modelli, A. [Dipartimento di Chimica “G. Ciamician,” Universitá di Bologna, Via Selmi 2, 40126 Bologna (Italy); Centro Interdipartimentale di Ricerca in Scienze Ambientali (CIRSA), Universitá di Bologna, Via S. Alberto 163, 48123 Ravenna (Italy)

2015-05-07

Phthalide, the simplest chain of conductive polymer thin film, was investigated by means of Electron Transmission Spectroscopy, Negative Ion Mass Spectrometry, and density functional theory quantum chemistry. It has been found that formation of gas-phase long-lived molecular anions of phthalide around 0.7 eV takes place through cleavage of a C–O bond of the pentacyclic ring of the parent molecular anion to give a vibrationally excited (electronically more stable) open-ring molecular anion. The energy of the transition state for ring opening of the parent negative ion is calculated to be 0.65 eV above the neutral ground state of the molecule. The energy (2.64 eV) evaluated for the corresponding transition state in the neutral molecule is much higher, so that the process of electron detachment from the anion must lead to a neutral molecule with its initial pentacyclic structure. The average lifetime of the molecular negative ions formed at an electron energy of 0.75 eV and 80 °C is measured to be about 100 μs. The known switching effect of thin phthalide films could stem from the presence of a similar open/closed transition state also in the polymer.

Member for conducting excess heat away from heat sources

International Nuclear Information System (INIS)

Cooke-Yarborough, E.H.

1975-01-01

Should a radioisotope-powered engine (e.g., a Stirling cycle engine for generating electricity) stop working for any reason, the radioisotope heat source will continue to generate heat. This will result in a rise in temperature which may cause overheating of and possible damage to the engine as well as to the heat source itself. The invention provides a support/location member for conducting excess heat from the heat source and which, in normal operation of the engine, will impede the conduction of heat away from the heat source and so reduce thermal losses. The member is of elongated form and comprises a stack of heat-conductive slugs disposed in a tube and in interspaced relationship along the axis of the tube. The tube supports the slugs in axial alignment. Means are provided for attaching an end one of the slugs to the heat source and means operable on overheating of said end one of the slugs are also provided whereby the slugs are able to move into heat-conducting contact with each other so as to conduct the excess heat away from said heat source. The slugs may be brazed to the tube whereby progressive overheating of the slugs along the stack results in an overheated slug being freed from attachment to the tube so as to allow the overheated slug to move along the stack and engage the next slug in line in heat-conducting contact. (U.S.)

Attachment of Escherichia coli and enterococci to particles in runoff.

Science.gov (United States)

Soupir, Michelle L; Mostaghimi, Saied; Dillaha, Theo

2010-01-01

Association of Escherichia coli and enterococci with particulates present in runoff from erodible soils has important implications for modeling the fate and transport of bacteria from agricultural sources and in the selection of management practices to reduce bacterial movement to surface waters. Three soils with different textures were collected from the Ap horizon (silty loam, silty clay loam, and loamy fine sand), placed in portable box plots, treated with standard cowpats, and placed under a rainfall simulator. Rainfall was applied to the plots until saturation-excess flow occurred for 30 min, and samples were collected 10, 20, and 30 min after initiation of the runoff event. The attachment of E. coli and enterococci to particles present in runoff was determined by a screen filtration and centrifugation procedure. Percentage of E. coli and enterococci attached to particulates in runoff ranged from 28 to 49%, with few statistically significant differences in attachment among the three soils. Similar partitioning release patterns were observed between E. coli and enterococci from the silty loam (r = 0.57) and silty clay loam soils (r = 0.60). At least 60% of all attached E. coli and enterococci were associated particles within an 8- to 62-microm particle size category. The results indicate that the majority of fecal bacteria attach to and are transported with manure colloids in sediment-laden flow regardless of the soil texture.

Electron Excess Doping and Effective Schottky Barrier Reduction on the MoS2/h-BN Heterostructure.

Science.gov (United States)

Joo, Min-Kyu; Moon, Byoung Hee; Ji, Hyunjin; Han, Gang Hee; Kim, Hyun; Lee, Gwanmu; Lim, Seong Chu; Suh, Dongseok; Lee, Young Hee

2016-10-12

Layered hexagonal boron nitride (h-BN) thin film is a dielectric that surpasses carrier mobility by reducing charge scattering with silicon oxide in diverse electronics formed with graphene and transition metal dichalcogenides. However, the h-BN effect on electron doping concentration and Schottky barrier is little known. Here, we report that use of h-BN thin film as a substrate for monolayer MoS 2 can induce ∼6.5 × 10 11 cm -2 electron doping at room temperature which was determined using theoretical flat band model and interface trap density. The saturated excess electron concentration of MoS 2 on h-BN was found to be ∼5 × 10 13 cm -2 at high temperature and was significantly reduced at low temperature. Further, the inserted h-BN enables us to reduce the Coulombic charge scattering in MoS 2 /h-BN and lower the effective Schottky barrier height by a factor of 3, which gives rise to four times enhanced the field-effect carrier mobility and an emergence of metal-insulator transition at a much lower charge density of ∼1.0 × 10 12 cm -2 (T = 25 K). The reduced effective Schottky barrier height in MoS 2 /h-BN is attributed to the decreased effective work function of MoS 2 arisen from h-BN induced n-doping and the reduced effective metal work function due to dipole moments originated from fixed charges in SiO 2 .

[Adult mother-daughter relationships and psychological well-being: attachment to mothers, depressive symptoms, and self-esteem].

Science.gov (United States)

Kitamura, Kotomi

2008-06-01

This study examined how daughter's reported quality of their mother-daughter relationships during childhood and adulthood is related to their psychological well-being (depressive symptoms and self-esteem). A cross-sectional sample of 363 women, age 26 to 35 years, completed questionnaires. The association between the quality of daughters' relationships with their mothers and their psychological well-being depended on the daughters' marital and parental status. Regression estimates suggested that among single daughters and married daughters with children, childhood attachment dimensions (avoidance and anxiety) significantly contributed to psychological well-being, even after controlling for the effects of current closeness and excessive dependence. Current closeness, and excessive care seeking and care giving to their mother contributed to the psychological well-being of single daughters and married daughters without children, even after controlling for the effects of childhood attachment.

Do the contact angle and line tension of surface-attached droplets depend on the radius of curvature?

Science.gov (United States)

Das, Subir K; Egorov, Sergei A; Virnau, Peter; Winter, David; Binder, Kurt

2018-06-27

Results from Monte Carlo simulations of wall-attached droplets in the three-dimensional Ising lattice gas model and in a symmetric binary Lennard-Jones fluid, confined by antisymmetric walls, are analyzed, with the aim to estimate the dependence of the contact angle [Formula: see text] on the droplet radius [Formula: see text] of curvature. Sphere-cap shape of the wall-attached droplets is assumed throughout. An approach, based purely on 'thermodynamic' observables, e.g. chemical potential, excess density due to the droplet, etc, is used, to avoid ambiguities in the decision which particles belong (or do not belong, respectively) to the droplet. It is found that the results are compatible with a variation [Formula: see text], [Formula: see text] being the contact angle in the thermodynamic limit ([Formula: see text]). The possibility to use such results to estimate the excess free energy related to the contact line of the droplet, namely the line tension, at the wall, is discussed. Various problems that hamper this approach and were not fully recognized in previous attempts to extract the line tension are identified. It is also found that the dependence of wall tensions on the difference of chemical potential of the droplet from that at the bulk coexistence provides effectively a change of the contact angle of similar magnitude. The simulation approach yields precise estimates for the excess density due to wall-attached droplets and the corresponding free energy excess, relative to a system without a droplet at the same chemical potential. It is shown that this information suffices to estimate nucleation barriers, not affected by ambiguities on droplet shape, contact angle and line tension.

Effect of temperature and pressure on excess electron mobility in n-hexane, 2,2,4-trimethylpentane, and tetramethylsilane

International Nuclear Information System (INIS)

Munoz, R.C.; Holroyd, R.A.

1986-01-01

Measurements of excess electron mobility are reported for liquid n-hexane, 2,2,4-trimethylpentane, and tetramethylsilane for pressures from 1 to 2500 bar and for temperatures from 18 to 120 0 C. For tetramethylsilane, a liquid that exhibits a high electron mobility, the mobility at constant density is proportional to T/sup -0.9/ between 25 and 100 0 C. The results are compared with the Basak--Cohen deformation potential theory. For n-hexane, where the mobility is low, Arrhenius behavior is observed. The isochoric activation energy increases with density. The results in this case are consistent with both the two-state and hopping models. In 2,2,4-trimethylpentane the mobility increases with increasing pressure at room temperature and decreases at high temperature. At 2500 bar and at intermediate temperatures (70--80 0 C) the mobility is approximately constant

Application of R-matrix theory to resonant reactive electron-molecule scattering: Vibrational excitation and dissociative attachment of N2 and F2

International Nuclear Information System (INIS)

Wong, C.F.; Light, J.C.

1984-01-01

Based on the R-matrix approach of Schneider et al. [J. Phys. B 12, L 365 (1979)] to reactive electron-molecule scattering, a new propagative R-matrix method (PRMM) is presented which is more appropriate for polyatomic systems. The new method should be useful in other calculations where complicated integrals need to be propagated. We also introduce an effective R-matrix model (ERMM) in which the usual resonance parameters (potential and width) can be used as input in model R-matrix calculations. The PRMM and ERMM have been applied to the electron-N 2 system and the electron-F 2 system. The results agree very well with previous calculations for both vibrationally inelastic scattering and dissociative attachment when identical potentials and parameters are used

Dissociative electron attachment and electronic excitation in Fe(CO)5

Czech Academy of Sciences Publication Activity Database

Allan, M.; Lacko, M.; Papp, P.; Matejčík, Š.; Zlatar, M.; Fabrikant, I. I.; Kočišek, Jaroslav; Fedor, Juraj

2018-01-01

Roč. 20, č. 17 (2018), s. 11692-11701 ISSN 1463-9076 R&D Projects: GA ČR GA17-04844S Grant - others:COST(XE) CM1301 Institutional support: RVO:61388955 Keywords : electrons * FEBID * electronic excitation Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 4.123, year: 2016

Kinetic theory analysis of electron attachment cooling in oxygen

International Nuclear Information System (INIS)

Skullerud, H.R.

1983-01-01

The attachment cooling effect observed by Hegerberg and Crompton (1983) has been analysed theoretically and numerically in a Boltzmann equation eigenvalue approach. The effect is highly sensitive to the shape and magnitude of the rotational excitation cross sections. When due account is taken of the rotational excitations associated with the (O 2 - ) negative ion resonances, good agreement between theory and experiment can be obtained with reasonable input cross-section data

Plasmid-dependent attachment of Agrobacterium tumefaciens to plant tissue culture cells.

Science.gov (United States)

Matthysse, A G; Wyman, P M; Holmes, K V

1978-11-01

Kinetic, microscopic, and biochemical studies show that virulent Ti (tumor inducing)-plasmid-containing strains of Agrobacterium attach to normal tobacco and carrot tissue culture cells. Kinetic studies showed that virulent strains of A. tumefaciens attach to the plant tissue culture cells in increasing numbers during the first 1 to 2 h of incubation of the bacteria with the plant cells. Five Ti-plasmid-containing virulent Agrobacterium strains showed greater attachment to tobacco cells than did five avirulent strains. Light and scanning electron microscopic observations confirmed that virulent strains showed little attachment. Bacterial attachment was blocked by prior incubation of the plant cells with lipopolysaccharide extracted from A. tumefaciens, but not from A. radiobacter, suggesting that bacterial lipopolysaccharide is one of the components involved in the attachment process. At least one other bacterial product may be required for attachment in tissue culture because the virulent A. tumefaciens NT1, which lacks the Ti plasmid, does not itself attach to tobacco cells, but its lipopolysaccharide does inhibit the attachment of virulent strains.

Attachment insecurity and obsessive-compulsive personality disorder among inpatients with serious mental illness.

Science.gov (United States)

Wiltgen, Anika; Adler, Herman; Smith, Ryan; Rufino, Katrina; Frazier, Christopher; Shepard, Christopher; Booker, Kirk; Simmons, Diedra; Richardson, Leah; Allen, Jon G; Fowler, J Christopher

2015-03-15

Obsessive-compulsive personality disorder (OCPD) is characterized by traits such as extreme rigidity, perfectionism, and controlling behavior, all of which have a negative impact on interpersonal functioning. Attachment theory provides a useful framework to elucidate the interpersonal dysfunction characteristic of OCPD; yet, there is a dearth of attachment research on OCPD in the context of severe mental illness. Attachment security and personality disorders were assessed in adult inpatients with severe mental illness. Propensity Score Matching (PSM) was used to match OCPD and control subjects on age, gender, number of psychiatric disorders, and number of criteria endorsed for borderline personality disorder. Consistent with hypotheses, the OCPD group (n=61) showed greater attachment avoidance than controls (n=61), and the avoidance was manifested in a predominance of the most insecure attachment style, fearful attachment. Correlations between attachment anxiety/avoidance with specific OCPD diagnostic criteria revealed that attachment avoidance was correlated with four of eight OCPD criteria across the full sample. Within the subset of OCPD patients, attachment avoidance was significantly correlated with OCPD criterion 3 (is excessively devoted to work and productivity to the exclusion of leisure activities and friendships). The use of self-report measure of attachment and the high burden of illness in the SMI population may not generalize to interview based assessment or outpatients, respectively. Findings attest to the severity of impairment in interpersonal functioning and attachment avoidance, in particular, is characteristic of OCPD patients. These results suggest that viable treatment targets include interpersonal functioning along with more classical features of OCPD such as perfectionism and obsessiveness in task performance. Copyright © 2014 Elsevier B.V. All rights reserved.

Transitory cell attachments in the differentiating glomerular epithelium of the opossum metanephros.

Science.gov (United States)

Krause, W J; Cutts, J H

1980-01-01

Numerous transitory intercellular attachments are observed between the central, lateral surfaces of adjacent glomerular epithelial cells in the differentiating renal corpuscle. The junctions are characterized by an increased electron density of the adjacent cell membranes and cytoplasm. The intervening intercellular space may contain an amorphous material of moderate electron density. The distribution and position of such temporary cell attachments, together with their modification and subsequent loss during the differentiation of podocytes, suggest that they play an important role in the histogenesis of the glomerular epithelium.

Paternal Attachment, Parenting Beliefs and Children's Attachment

Science.gov (United States)

Howard, Kimberly S.

2010-01-01

Relationships between fathers' romantic attachment style, parenting beliefs and father-child attachment security and dependence were examined in a diverse sample of 72 fathers of young children. Paternal romantic attachment style was coded based on fathers' endorsement of a particular style represented in the Hazan and Shaver Three-Category…

Temperature dependence of the cross section for the fragmentation of thymine via dissociative electron attachment

Energy Technology Data Exchange (ETDEWEB)

Kopyra, Janina [Faculty of Science, Siedlce University, 3 Maja 54, 08-110 Siedlce (Poland); Abdoul-Carime, Hassan, E-mail: hcarime@ipnl.in2p3.fr [Université de Lyon, Université Claude Bernard Lyon1, Institut de Physique Nucléaire de Lyon, CNRS/IN2P3 UMR 5822, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex (France)

2015-05-07

Providing experimental values for absolute Dissociative Electron Attachment (DEA) cross sections for nucleobases at realistic biological conditions is a considerable challenge. In this work, we provide the temperature dependence of the cross section, σ, of the dehydrogenated thymine anion (T − H){sup −} produced via DEA. Within the 393-443 K temperature range, it is observed that σ varies by one order of magnitude. By extrapolating to a temperature of 313 K, the relative DEA cross section for the production of the dehydrogenated thymine anion at an incident energy of 1 eV decreases by 2 orders of magnitude and the absolute value reaches approximately 6 × 10{sup −19} cm{sup 2}. These quantitative measurements provide a benchmark for theoretical prediction and also a contribution to a more accurate description of the effects of ionizing radiation on molecular medium.

Electron: Cluster interactions

International Nuclear Information System (INIS)

Scheidemann, A.A.; Knight, W.D.

1994-02-01

Beam depletion spectroscopy has been used to measure absolute total inelastic electron-sodium cluster collision cross sections in the energy range from E ∼ 0.1 to E ∼ 6 eV. The investigation focused on the closed shell clusters Na 8 , Na 20 , Na 40 . The measured cross sections show an increase for the lowest collision energies where electron attachment is the primary scattering channel. The electron attachment cross section can be understood in terms of Langevin scattering, connecting this measurement with the polarizability of the cluster. For energies above the dissociation energy the measured electron-cluster cross section is energy independent, thus defining an electron-cluster interaction range. This interaction range increases with the cluster size

Impact of Maternal Attachment Style on Mother to Infant Attachment

Directory of Open Access Journals (Sweden)

Moghaddam Hoseini V

2011-08-01

Full Text Available Background and Objectives: Maternal attachment has the potential to affect both child development and parenting. As such, mother-infant attachment has been considered an important topic in recent years. The aim of this study was to determine the relationship between maternal adult attachment style, the maternal obstetric and demographic characteristics and mother-infant attachment.Methods: In this descriptive-correlational study, 102 women who had referred to health centers in Mashhad in 2008 and who had inclusion criteriawere selected using stratified cluster sampling. After interview about obstetric and demographic characteristics, they were asked to complete the "Revised Adult Attachment Scale" and "Mother to Infant Attachment Inventory" for assessment of maternal attachment style and mother-infant attachment 4-5 weeks after delivery. Data were analyzed by Pearson Correlation, Kruskal-wallis and Mann-whitney statistical tests.Results: In this study, themean of mother-infant attachment was found to be 97.486.12 and the mean of secure adult attachment was higher than that of other styles (16.893.97. Although, there were negative significant relationship between maternal avoidant style and mother-infant attachment (p=0.037,r=-0/20, there were no relationship between maternal age and education, parity, type of delivery and mother-infant attachment.Conclusion: The results of this research show that maternal attachment style is one of the factors of mother -infant attachment.

A new time of flight mass spectrometer for absolute dissociative electron attachment cross-section measurements in gas phase

Science.gov (United States)

Chakraborty, Dipayan; Nag, Pamir; Nandi, Dhananjay

2018-02-01

A new time of flight mass spectrometer (TOFMS) has been developed to study the absolute dissociative electron attachment (DEA) cross section using a relative flow technique of a wide variety of molecules in gas phase, ranging from simple diatomic to complex biomolecules. Unlike the Wiley-McLaren type TOFMS, here the total ion collection condition has been achieved without compromising the mass resolution by introducing a field free drift region after the lensing arrangement. The field free interaction region is provided for low energy electron molecule collision studies. The spectrometer can be used to study a wide range of masses (H- ion to few hundreds atomic mass unit). The mass resolution capability of the spectrometer has been checked experimentally by measuring the mass spectra of fragment anions arising from DEA to methanol. Overall performance of the spectrometer has been tested by measuring the absolute DEA cross section of the ground state SO2 molecule, and the results are satisfactory.

Electron transport measurements in methane using an improved pulsed Townsend technique

International Nuclear Information System (INIS)

Hunter, S.R.; Carter, J.G.; Christophorou, L.G.

1986-01-01

An improved pulsed Townsend technique for the measurement of electron transport parameters in gases is described. The accuracy and sensitivity of the technique have been investigated by performing, respectively, electron attachment coefficient measurements in pure O 2 over a wide range of E/N at selected O 2 pressures and by determining the electron attachment and ionization coefficients and electron drift velocity in CH 4 over a wide E/N range. Good agreement has been obtained between the present and the previously published electron attachment coefficients in O 2 and for the drift velocity measurements in CH 4 . The data on the electron attachment coefficient in CH 4 (measured for the first time) showed that with the present improved pulsed Townsend method, electron attachment coefficients up to 10 times smaller than the ionization coefficients at a given E/N value can be accurately measured. Our measurements of the electron attachment and ionization coefficients in CH 4 are in good agreement with a Boltzmann equation analysis of the electron gain and loss processes in CH 4 using published electron scattering cross sections for this molecule

Impact of Maternal Attachment Style on Mother to Infant Attachment

Directory of Open Access Journals (Sweden)

V Moghaddam Hoseini

2012-05-01

Full Text Available

Background and Objectives: Maternal attachment has the potential to affect both child development and parenting. As such, mother-infant attachment has been considered an important topic in recent years. The aim of this study was to determine the relationship between maternal adult attachment style, the maternal obstetric and demographic characteristics and mother-infant attachment.

Methods: In this descriptive-correlational study, 102 women who had referred to health centers in Mashhad in 2008 and who had inclusion criteriawere selected using stratified cluster sampling. After interview about obstetric and demographic characteristics, they were asked to complete the "Revised Adult Attachment Scale" and "Mother to Infant Attachment Inventory" for assessment of maternal attachment style and mother-infant attachment 4-5 weeks after delivery. Data were analyzed by Pearson Correlation, Kruskal-wallis and Mann-whitney statistical tests.

Results: In this study, themean of mother-infant attachment was found to be 97.48±6.12 and the mean of secure adult attachment was higher than that of other styles (16.89±3.97. Although, there were negative significant relationship between maternal avoidant style and mother-infant attachment (p=0.037,r=-0/20, there were no relationship between maternal age and education, parity, type of delivery and mother-infant attachment.

Conclusion: The results of this research show that maternal attachment style is one of the factors of mother -infant attachment.

On the calculation of the energies of dissociation, cohesion, vacancy formation, electron attachment, and the ionization potential of small metallic clusters containing a monovacancy

Science.gov (United States)

Pogosov, V. V.; Reva, V. I.

2017-09-01

In terms of the model of stable jellium, self-consistent calculations of spatial distributions of electrons and potentials, as well as of energies of dissociation, cohesion, vacancy formation, electron attachment, and ionization potentials of solid clusters of Mg N , Li N (with N ≤ 254 ) and of clusters containing a vacancy ( N ≥ 12) have been performed. The contribution of a monovacancy to the energy of the cluster and size dependences of its characteristics and of asymptotics have been discussed. Calculations have been performed using a SKIT-3 cluster at Glushkov Institute of Cybernetics, National Academy of Sciences, Ukraine (Rpeak = 7.4 Tflops).

Frontier molecular orbitals of a single molecule adsorbed on thin insulating films supported by a metal substrate: electron and hole attachment energies.

Science.gov (United States)

Scivetti, Iván; Persson, Mats

2017-09-06

We present calculations of vertical electron and hole attachment energies to the frontier orbitals of a pentacene molecule absorbed on multi-layer sodium chloride films supported by a copper substrate using a simplified density functional theory (DFT) method. The adsorbate and the film are treated fully within DFT, whereas the metal is treated implicitly by a perfect conductor model. We find that the computed energy gap between the highest and lowest unoccupied molecular orbitals-HOMO and LUMO -from the vertical attachment energies increases with the thickness of the insulating film, in agreement with experiments. This increase of the gap can be rationalised in a simple dielectric model with parameters determined from DFT calculations and is found to be dominated by the image interaction with the metal. We find, however, that this simplified model overestimates the downward shift of the energy gap in the limit of an infinitely thick film.

The water-water cycle in leaves is not a major alternative electron sink for dissipation of excess excitation energy when CO2 assimilation is restricted

NARCIS (Netherlands)

Driever, S.M.; Baker, N.R.

2011-01-01

Electron flux from water via photosystem II (PSII) and PSI to oxygen (water–water cycle) may provide a mechanism for dissipation of excess excitation energy in leaves when CO2 assimilation is restricted. Mass spectrometry was used to measure O2 uptake and evolution together with CO2 uptake in leaves

Attachment and Psychopathology

Directory of Open Access Journals (Sweden)

Mehmet Fatih Ustundag

2011-06-01

Full Text Available The type of attachment defined in the early stages of life and thought to be continuous, is a phenomenon that shapes the pattern of how a person makes contact with others. The clinical appearance of every type of attachment is different and each one has prospective and retrospective phenomenological reflections. In all stages of life and in close relationships, it can be observed if a person gets in close contact with someone else and if this relation bears supportive and protective qualities. According to attachment theorists, once it is defined as safe or unsafe during nursing period, it shows little change. Starting from Bowlby’s work, unsafe attachment type is considered as the determining factor of psychopathology in the later periods of life, while safe attachment is considered as in relation with healthy processes. The nature’s original model is safe attachment. Anxious/indecisive attachment, an unsafe attachment type, is associated with anxiety disorders and depressive disorder, while avoidant attachment is associated with behavior disorder and other extroverted pathologies. Disorganized/disoriented attachment is considered to be together with dissociative disorder. The aim of this paper is to review attachment theory and the relation between attachment and psychopathology.

Electron Paramagnetic Resonance of a Single NV Nanodiamond Attached to an Individual Biomolecule.

Science.gov (United States)

Teeling-Smith, Richelle M; Jung, Young Woo; Scozzaro, Nicolas; Cardellino, Jeremy; Rampersaud, Isaac; North, Justin A; Šimon, Marek; Bhallamudi, Vidya P; Rampersaud, Arfaan; Johnston-Halperin, Ezekiel; Poirier, Michael G; Hammel, P Chris

2016-05-10

Electron paramagnetic resonance (EPR), an established and powerful methodology for studying atomic-scale biomolecular structure and dynamics, typically requires in excess of 10(12) labeled biomolecules. Single-molecule measurements provide improved insights into heterogeneous behaviors that can be masked in ensemble measurements and are often essential for illuminating the molecular mechanisms behind the function of a biomolecule. Here, we report EPR measurements of a single labeled biomolecule. We selectively label an individual double-stranded DNA molecule with a single nanodiamond containing nitrogen-vacancy centers, and optically detect the paramagnetic resonance of nitrogen-vacancy spins in the nanodiamond probe. Analysis of the spectrum reveals that the nanodiamond probe has complete rotational freedom and that the characteristic timescale for reorientation of the nanodiamond probe is slow compared with the transverse spin relaxation time. This demonstration of EPR spectroscopy of a single nanodiamond-labeled DNA provides the foundation for the development of single-molecule magnetic resonance studies of complex biomolecular systems. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Atomic and molecular physics

International Nuclear Information System (INIS)

Anderson, V.E.; Cox, J.T.; Huynh, Q.A.

1975-01-01

Topics covered include: electron attachment to SO 2 in high pressure gases; long-lived parent negative ions formed via nuclear-excited Feshbach resonances, part IV, a systematic study of NO 2 -containing benzene derivatives; threshold-electron excitation and compound-negative-ion states of aromatic hydrocarbons; linking of existing data on electron-molecule interactions in gases with those in the liquid phase; slowing down of subexcitation electrons in polyatomic gases; electron mobilities in high-pressure gases (''quasi-liquids''); measurement of the mobility of excess electrons in liquids; potential energy function of an excess electron in a nonpolar liquid; electron mobilities in gases and liquids; photophysics of aromatic hydrocarbons; synthesis of electron-molecule interactions with benzene and benzene derivatives; and spin-off of basic studies on electron attachment to, and elastic scattering from, polyatomic molecules. 14 figures, 2 tables

Attachment and prejudice.

Science.gov (United States)

Carnelley, Katherine B; Boag, Elle M

2018-04-16

There is a paucity of research that examines prejudice from an attachment theory perspective. Herein we make theoretical links between attachment patterns and levels of prejudice. Perceptions of outgroup threat, which activate the attachment system, are thought to lead to fear and prejudice for those high in attachment anxiety, and to distancing and prejudice for those high in attachment avoidance. We review the literature that examines the associations between attachment patterns and prejudice; evidence from attachment priming studies suggests a causal role of attachment security in reducing prejudice. We identify several mediators of these links: empathy, negative emotions, trust, social dominance orientation, romanticism, and contact quality. Future research should manipulate potential mediators and use psychophysiological assessments of threat. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of electron-electron collisions on the phase transition and kinetics of nonequilibrium superconductors

International Nuclear Information System (INIS)

Elesin, V.F.; Kashurnikov, V.A.; Kondrashov, V.E.; Shamraev, B.N.

1983-01-01

An explicit expression is obtained for the distribution function of excess quasiparticles, taking into account electron-electron collisions in nonequilibrium superconductors. It is shown that the character of the phase transition may change at a definite ratio of the electron-electron and electron-phonon interaction constants: the dependence of the order parameter on the power of the source becomes single-valued. In addition, diffusion instability and paramagnetism of the superconductors arise. The multiplication factor of the excess quasiparticles due to electron-electron collisions and to reabsorption of phonons is calculated

Dynamics of an excess hole in the 1-methyl-1-butyl-pyrrolidinium dicyanamide ionic-liquid

Science.gov (United States)

Wu, Fei; Xu, Changhui; Margulis, Claudio J.

2018-05-01

In a set of recent publications [C. J. Margulis et al., J. Am. Chem. Soc. 133, 20186 (2011); C. H. Xu et al., J. Am. Chem. Soc. 135, 17528 (2013); C. H. Xu and C. J. Margulis, J. Phys. Chem. B 119, 532 (2015); and K. B. Dhungana et al., J. Phys. Chem. B 121, 8809 (2017)], we explored for selected ionic liquids the early stages of excess charge localization and reactivity relevant both to electrochemical and radiation chemistry processes. In particular, Xu and Margulis [J. Phys. Chem. B 119, 532 (2015)] explored the dynamics of an excess electron in 1-methyl-1-butyl-pyrrolidinium dicyanamide. When electrons are produced from an ionic liquid, the more elusive hole species are also generated. Depending on the nature of cations and anions and the relative alignment of their electronic states in the condensed phase, the very early hole species can nominally be neutral radicals—if the electron is generated from anions—or doubly charged radical cations if their origin is from cations. However, in reality early excess charge localization is more complex and often involves more than one ion. The dynamics and the transient spectroscopy of the hole are the main objects of this study. We find that in the case of 1-methyl-1-butyl-pyrrolidinium dicyanamide, it is the anions that can most easily lose an electron becoming radical species, and that hole localization is mostly on anionic nitrogen. We also find that the driving force for localization of an excess hole appears to be smaller than that for an excess electron in 1-methyl-1-butyl-pyrrolidinium dicyanamide. The early transient hole species can absorb light in the visible, ultraviolet, and near infrared regions, and we are able to identify the type of states being connected by these transitions.

The use of electronic alerts in primary care computer systems to identify the excessive prescription of short-acting beta2-agonists for people with asthma: a systematic review.

Science.gov (United States)

McKibben, Shauna; De Simoni, Anna; Bush, Andy; Thomas, Mike; Griffiths, Chris

2018-04-16

Computers are increasingly used to improve prescribing decisions in the management of long-term conditions however the effects on asthma prescribing remain unclear. We aimed to synthesise the evidence for the use of computerised alerts that identify excessive prescribing of short-acting beta 2 -agonists (SABAs) to improve asthma management for people with asthma. MEDLINE, CINAHL, Embase, Cochrane and Scopus databases (1990-2016) were searched for randomised controlled trials using electronic alerts to identify excessive prescribing of SABAs for people with asthma in primary care. Inclusion eligibility, quality appraisal (Cochrane risk of bias tool) and data extraction were performed by two independent reviewers. Findings were synthesised narratively. A total of 2035 articles were screened and four trials were eligible. Three studies had low risk of bias: one reported a positive effect on our primary outcome of interest, excessive SABA prescribing; another reported positive effects on the ratio of inhaled corticosteroid (ICS)-SABA prescribing, and asthma control; a third reported no effect on outcomes of interest. One study at high risk of bias reported a reduction in exacerbations and primary care consultations. There is some evidence that electronic alerts reduce excessive prescribing of SABAs, when delivered as part of a multicomponent intervention in an integrated health care system. However due to the variation in health care systems, intervention design and outcomes measured, further research is required to establish optimal design of alerting and intervening systems.

Depression symptoms and reasons for gambling sequentially mediate the associations between insecure attachment styles and problem gambling.

Science.gov (United States)

Keough, Matthew T; Penniston, Trinda L; Vilhena-Churchill, Natalie; Michael Bagby, R; Quilty, Lena C

2018-03-01

One of the central pathways to problem gambling (PG) is gambling to cope with negative moods, which is a cardinal feature of depression. Insecure attachment styles are also etiologically related to depression; and, therefore, by extension, those who are insecurely attached may engage in excessive gambling behaviors to cope with depression. In this study, we aimed to evaluate this and to this end predicted that depression severity and coping motives for gambling would conjointly mediate the relations between insecure attachment styles and PG. Data came from a larger investigation of PG within mood disorders. Participants exhibited a lifetime depressive or bipolar disorder and endorsed a mood episode within the past ten years. Participants (N=275) completed self-report measures during a two-day assessment. Path analysis supported two main indirect effects. First, anxious attachment predicted elevated depression, which in turn predicted increased coping motives for gambling, which subsequently predicted greater PG severity. Second, this double mediational pathway was also observed for avoidant attachment. Results suggest that insecure attachment relates to PG via depressive symptoms and coping-related gambling motives. Mood symptoms and associated gambling motives are malleable and are promising targets of gambling interventions for insecurely attached individuals. Copyright © 2017 Elsevier Ltd. All rights reserved.

NEW METHOD TO ATTACH WEARABLE ELECTRONICS TO CLOTHS

Directory of Open Access Journals (Sweden)

FERRI PASCUAL Josué

2015-05-01

Full Text Available The integration of electronic devices and sensors into textiles has many different potential applications. Textile fabrics, from clothing to upholstery and home textiles, are an integral part of daily life and the ability to combine electronics into textiles means that a huge range of valuable data can be collected and used by the wearer to monitor their health, performance and wellbeing, among other uses. One of the most pressing challenges is that of interconnecting electronic components via the textile fibres in a robust and reliable way. Another aspect to be studied is the ability for the electronics to be connected and disconnected when necessary; for example, when charging the batteries or washing the garment. It is this aspect that has been considered by this development to facilitate ease-of-use among the older people. In addition, the complete package must be comfortable enough not to restrict movement, and must be unobtrusive so as to avoid any embarrassment to the wearer. The present paper presents a new solution for the connection of electronic measuring and monitoring devices to textile sensors to monitor variables such as movement, temperature, heart rate and breathing.

'Adoption and attachment theory' the attachment models of adoptive mothers and the revision of attachment patterns of their late-adopted children.

Science.gov (United States)

Pace, C S; Zavattini, G C

2011-01-01

This study examined the attachment patterns of late-adopted children (aged 4-7) and their adoptive mothers during the first 7- to 8-month period after adoption and aimed to evaluate the effect of adoptive mothers' attachment security on the revision of the attachment patterns of their late-adopted children. We assessed attachment patterns in 20 adoptive dyads and 12 genetically related dyads at two different times: T1 (time 1) within 2 months of adoption and T2 (time 2) 6 months after T1. The children's behavioural attachment patterns were assessed using the Separation-Reunion Procedure and the children's representational (verbal) attachment patterns using the Manchester Child Attachment Story Task. The attachment models of the adoptive mothers were classified using the Adult Attachment Interview. We found that there was a significant enhancement of the late-adopted children's attachment security across the time period considered (P= 0.008). Moreover, all the late-adopted children who showed a change from insecurity to security had adoptive mothers with secure attachment models (P= 0.044). However, the matching between maternal attachment models and late-adopted children's attachment patterns (behaviours and representations) was not significant. Our data suggest that revision of the attachment patterns in the late-adopted children is possible but gradual, and that the adoptive mothers' attachment security makes it more likely to occur. © 2010 Blackwell Publishing Ltd.

Attachment and mentalization and their association with child and adolescent eating pathology: A systematic review.

OpenAIRE

Jewell, T.; Collyer, H.; Gardner, T.; Tchanturia, K.; Simic, M.; Fonagy, P.; Eisler, I.

2016-01-01

OBJECTIVE: Insecure attachment and mentalizing difficulties have been associated with eating pathology in adulthood. However, it is unclear whether eating pathology is associated with attachment or mentalization in children. The aim of this study is to systematically review the literature in this emerging field. METHOD: Electronic databases were used to search for articles. RESULTS: Twenty-two studies were identified. In the 15 studies investigating attachment, an association with eating path...

Attachment of carbon nanotubes to atomic force microscope probes

International Nuclear Information System (INIS)

Gibson, Christopher T.; Carnally, Stewart; Roberts, Clive J.

2007-01-01

In atomic force microscopy (AFM) the accuracy of data is often limited by the tip geometry and the effect on this geometry of wear. One way to improve the tip geometry is to attach carbon nanotubes (CNT) to AFM tips. CNTs are ideal because they have a small diameter (typically between 1 and 20 nm), high aspect ratio, high strength, good conductivity, and almost no wear. A number of methods for CNT attachment have been proposed and explored including chemical vapour deposition (CVD), dielectrophoresis, arc discharge and mechanical attachment. In this work we will use CVD to deposit nanotubes onto a silicon surface and then investigate improved methods to pick-up and attach CNTs to tapping mode probes. Conventional pick-up methods involve using standard tapping mode or non-contact mode so as to attach only those CNTs that are aligned vertically on the surface. We have developed improved methods to attach CNTs using contact mode and reduced set-point tapping mode imaging. Using these techniques the AFM tip is in contact with a greater number of CNTs and the rate and stability of CNT pick-up is improved. The presence of CNTs on the modified AFM tips was confirmed by high-resolution AFM imaging, analysis of the tips dynamic force curves and scanning electron microscopy (SEM)

Oxidant enhancement in martian dust devils and storms: storm electric fields and electron dissociative attachment.

Science.gov (United States)

Delory, Gregory T; Farrell, William M; Atreya, Sushil K; Renno, Nilton O; Wong, Ah-San; Cummer, Steven A; Sentman, Davis D; Marshall, John R; Rafkin, Scot C R; Catling, David C

2006-06-01

Laboratory studies, numerical simulations, and desert field tests indicate that aeolian dust transport can generate atmospheric electricity via contact electrification or "triboelectricity." In convective structures such as dust devils and dust storms, grain stratification leads to macroscopic charge separations and gives rise to an overall electric dipole moment in the aeolian feature, similar in nature to the dipolar electric field generated in terrestrial thunderstorms. Previous numerical simulations indicate that these storm electric fields on Mars can approach the ambient breakdown field strength of approximately 25 kV/m. In terrestrial dust phenomena, potentials ranging from approximately 20 to 160 kV/m have been directly measured. The large electrostatic fields predicted in martian dust devils and storms can energize electrons in the low pressure martian atmosphere to values exceeding the electron dissociative attachment energy of both CO2 and H2O, which results in the formation of the new chemical products CO/O- and OH/H-, respectively. Using a collisional plasma physics model, we present calculations of the CO/O- and OH/H- reaction and production rates. We demonstrate that these rates vary geometrically with the ambient electric field, with substantial production of dissociative products when fields approach the breakdown value of approximately 25 kV/m. The dissociation of H2O into OH/H- provides a key ingredient for the generation of oxidants; thus electrically charged dust may significantly impact the habitability of Mars.

The attachment system in fledgling relationships: an activating role for attachment anxiety.

Science.gov (United States)

Eastwick, Paul W; Finkel, Eli J

2008-09-01

Is it sensible to study attachment dynamics between potential romantic partners before they share a full-fledged attachment bond? The present data indicate that such an approach may reveal novel insights about initial attraction processes. Four studies suggest that the state-like experience of attachment anxiety has functional implications within fledgling (i.e., desired or undeveloped) romantic relationships, well before the formation of an attachment bond. Studies 1 and 3 reveal that attachment anxiety directed toward a particular romantic interest is elevated before (in comparison with after) participants report being in an established relationship. Studies 2 and 3 demonstrate that such partner-specific attachment anxiety predicts attachment-relevant outcomes in fledgling relationships, including proximity seeking, safe haven, secure base, passionate love, and other approach behaviors. These associations were reliable above and beyond (and were typically as strong as or stronger than) the effect of sexual desire. Finally, Study 4 presents evidence that partner-specific attachment anxiety may cause several of these attachment-relevant outcomes. Attachment anxiety seems to be a normative experience and may signal the activation of the attachment system during the earliest stages of romantic relationships.

Blade attachment assembly

Science.gov (United States)

Garcia-Crespo, Andres Jose; Delvaux, John McConnell; Miller, Diane Patricia

2016-05-03

An assembly and method for affixing a turbomachine rotor blade to a rotor wheel are disclosed. In an embodiment, an adaptor member is provided disposed between the blade and the rotor wheel, the adaptor member including an adaptor attachment slot that is complementary to the blade attachment member, and an adaptor attachment member that is complementary to the rotor wheel attachment slot. A coverplate is provided, having a coverplate attachment member that is complementary to the rotor wheel attachment slot, and a hook for engaging the adaptor member. When assembled, the coverplate member matingly engages with the adaptor member, and retains the blade in the adaptor member, and the assembly in the rotor wheel.

The nature of excess electrons in anatase and rutile from hybrid DFT and RPA.

Science.gov (United States)

Spreafico, Clelia; VandeVondele, Joost

2014-12-21

The behavior of excess electrons in undoped and defect free bulk anatase and rutile TiO2 has been investigated by state-of-the-art electronic structure methods including hybrid density functional theory (DFT) and the random phase approximation (RPA). Consistent with experiment, charge trapping and polaron formation is observed in both anatase and rutile. The difference in the anisotropic shape of the polarons is characterized, confirming for anatase the large polaron picture. For anatase, where polaron formation energies are small, charge trapping is observed also with standard hybrid functionals, provided the simulation cell is sufficiently large (864 atoms) to accommodate the lattice relaxation. Even though hybrid orbitals are required as a starting point for RPA in this system, the obtained polaron formation energies are relatively insensitive to the amount of Hartree-Fock exchange employed. The difference in trapping energy between rutile and anatase can be obtained accurately with both hybrid functionals and RPA. Computed activation energies for polaron hopping and delocalization clearly show that anatase and rutile might have different charge transport mechanisms. In rutile, only hopping is likely, whereas in anatase hopping and delocalization are competing. Delocalization will result in conduction-band-like and thus enhanced transport. Anisotropic conduction, in agreement with experimental data, is observed, and results from the tendency to delocalize in the [001] direction in rutile and the (001) plane in anatase. For future work, our calculations serve as a benchmark and suggest RPA on top on hybrid orbitals (PBE0 with 30% Hartree-Fock exchange), as a suitable method to study the rich chemistry and physics of TiO2.

Evaluation of Psychiatric Comorbidity in Adolescence with Excessive Computer Game Players

Directory of Open Access Journals (Sweden)

Anita alaghmand

2016-12-01

Full Text Available Despite of the increasing use of games, yet assessment of causes and consequences of these games were less considered. The purpose of this study was to determine the psychiatric disorders in comparison with usual game users. Firstly PVGT questionnaire was given to 1056 male students at ages 12-18. Students who had score 70 or higher had eligible criteria for excessive or problematic or addictive game user. In the second stage of study, the addicted user group was interviewed by clinical psychologist (M.S with use of K-SADS. In people that had early symptoms of disorders, questionnaires attachment of K-SADS were used, finally the interview based on DSMIV criteria was performed for confirmation of diagnose of psychiatric disorders. In this study of 1000 male, 46 male equivalents to 4.3 percent were excessive or addictive game users. Prevalence of MDD, types of phobias, TSD, SAD, panic disorder, ADHD and OCD although were predominantly higher percent in addictive game users, difference was not significant based on(P< 0.05. The overall prevalence of anxiety disorders and psychiatric problems was significantly higher in this group. In this study a large range of disorders were found. The excessive users of video game were associated with an increased presence of psychiatric disorders specially anxiety disorders. In the future studies, the causal role of excessive game abuse and side effects of this game on mental health should be considered.

Degradation phenomena of magnetic attachments used clinically in the oral environment

Science.gov (United States)

Chung, Chae-Heon; Choe, Han-Cheol; Kwak, Jong-Ha

2006-08-01

The purpose of this study was to investigate the mechanisms involved in the failure of magnetic attachments used to retain dental prostheses. Dyna magnets were retrieved from dentures that had failed after 34 months of clinical use. These magnetic attachments were prepared and sectioned so as to observe the corrosion surface and layer in order to analyze the corrosion behaviors of the attachments. The corroded surface was observed under a field emission scanning electron microscope (FE-SEM) (JSM 840A, JEOL, Japan). An X-ray diffractometer (XRD) was used to analyze the corrosion product formed due to corrosion in the oral environment. Erosion-corrosion started in the uneven portion of the stainless steel cover in the magnetic attachments composed with Nd-Fe-B alloy. Corrosion was initiated on the worn stainless steel surface, followed by spalling of magnetic material due to corrosive solution. The corrosion rate increased drastically after the corrosion product caused spalling in Nd-Fe-B alloy. Corrosion initiated in the uneven stainless steel surface as well as in the welded zone. In conclusion, the failure of magnetic attachments may occur by either welding failure or breakdown of the encapsulating material. Thus, we believe that treating the surface of magnetic attachments would resolve the corrosion problem seen in magnetic attachments to some extent.

Cell attachment properties of Portland cement-based endodontic materials: biological and methodological considerations.

Science.gov (United States)

Ahmed, Hany Mohamed Aly; Luddin, Norhayati; Kannan, Thirumulu Ponnuraj; Mokhtar, Khairani Idah; Ahmad, Azlina

2014-10-01

The attachment and spreading of mammalian cells on endodontic biomaterials are an area of active research. The purpose of this review is to discuss the cell attachment properties of Portland cement (PC)-based materials by using scanning electron microscope (SEM). In addition, methodological aspects and technical challenges are discussed. A PubMed electronic search was conducted by using appropriate key words to identify the available investigations on the cell attachment properties of PC-based endodontic materials. After retrieving the full text of related articles, the cross citations were also identified. A total of 23 articles published between January 1993 and October 2013 were identified. This review summarizes the cell attachment properties of commercial and experimental PC-based materials on different cell cultures by using SEM. Methodological procedures, technical challenges, and relevance of SEM in determining the biological profile of PC-based materials are discussed. SEM observations demonstrate that commercial MTA formulations show favorable cell attachment properties, which is consistent with their successful clinical outcomes. The favorable cell attachment properties of PC and its modified formulations support its potential use as a substitute for mineral trioxide aggregate. However, researchers should carefully select cell types for their SEM investigations that would be in contact with the proposed PC-based combinations in the clinical situation. Despite being a technical challenge, SEM provides useful information on the cell attachment properties of PC-based materials; however, other assays for cell proliferation and viability are essential to come up with an accurate in vitro biological profile of any given PC-based formulation. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Dissociative electron attachment to DNA-diamine thin films: Impact of the DNA close environment on the OH{sup −} and O{sup −} decay channels

Energy Technology Data Exchange (ETDEWEB)

Boulanouar, Omar; Fromm, Michel; Mavon, Christophe [UMR CNRS 6249 Chrono-Environnement, Laboratoire de Chimie Physique et Rayonnements – Alain Chambaudet, LRC CEA, Université de Franche-Comté, 16 route de Gray, F-25030 Besançon cedex (France); Cloutier, Pierre; Sanche, Léon [Groupe en Sciences des Radiations, Département de Médecine Nucléaire et de Radiobiologie, Faculté de Médecine, Université de Sherbrooke, Québec J1H 5N4 (Canada)

2013-08-07

We measure the desorption of anions stimulated by the impact of 0–20 eV electrons on highly uniform thin films of plasmid DNA-diaminopropane. The results are accurately correlated with film thickness and composition by AFM and XPS measurements, respectively. Resonant structures in the H{sup −}, O{sup −}, and OH{sup −} yield functions are attributed to the decay of transient anions into the dissociative electron attachment (DEA) channel. The diamine induces ammonium-phosphate bridges along the DNA backbone, which suppresses the DEA O{sup −} channel and in counter-part increases considerably the desorption of OH{sup −}. The close environment of the phosphate groups may therefore play an important role in modulating the rate and type of DNA damages induced by low energy electrons.

Integrating Emotional Attachment and Sustainability in Electronic Product Design

Directory of Open Access Journals (Sweden)

Alex Lobos

2013-03-01

Full Text Available Current models for Information and Communication Technology (ICT products encourage frequent product replacement with newer versions that offer only minor incremental improvements. This pattern, named planned obsolescence, diminishes user experience and shortens product lifespan. This paper presents the conceptual basis for a two-part integrated approach to combating planned obsolescence in ICT devices. First, design for emotional attachment, which creates products that users enjoy, value, and use for longer. Second, technological adaptability, which anticipates product upgrades and repairs as new technologies emerge. A model interdisciplinary design course in industrial design and sustainability, also described herein, trains students to apply this approach to create innovative ICT products with smaller environmental footprints.

Electron optical characteristics of a concave electrostatic electron mirror for a scanning electron microscope

International Nuclear Information System (INIS)

Hamarat, R.T.; Witzani, J.; Hoerl, E.M.

1984-08-01

Numerical computer calculations are used to explore the design characteristics of a concave electrostatic electron mirror for a mirror attachment for a conventional scanning electron microscope or an instrument designed totally as a scanning electron mirror microscope. The electron paths of a number of set-ups are calculated and drawn graphically in order to find the optimum shape and dimensions of the mirror geometry. This optimum configuration turns out to be the transition configuration between two cases of electron path deflection, towards the optical axis of the system and away from it. (Author)

Dissociative electron attachment to methyl chloride: A quasi-diatomic potential curve for the fragmentation of the metastable CH3Cl- anion

International Nuclear Information System (INIS)

Mach, P.; Urban, J.; Staemmler, V.

2009-01-01

Potential energy curves have been calculated for the dissociation of the neutral CH 3 Cl molecule and its negative ion into CH 3 + Cl and CH 3 +Cl - , respectively. The neutral molecule and the anion could be treated by means of standard wave function based quantum chemical ab initio methods for C-Cl distances larger than about 2.4 A, where CH 3 Cl - is a stable anion. In the present calculation MP3 and CCSD(T) were employed. At shorter C-Cl distances the CH 3 Cl - anion is only metastable and cannot be treated by such methods. We have applied a stabilization scheme, first proposed by Nestmann and Peyerimhoff, to stabilize the metastable anion by adding extra positive charges to the molecule. By this trick it was possible to generate the resonance energy E res and width Γ as functions of the C-Cl distance in the resonance regime between 1.5 and 2.5 A. The calculated values for the threshold energy E thresh and the exothermicity ΔE 0 of the DEA (dissociative electron attachment) process are in very good agreement with experiment; the vertical attachment energy (VAE) is smaller than its experimental counterpart

Alternative search strategies to explore ATLAS diboson excess

Indian Academy of Sciences (India)

Charanjit K Khosa

2017-10-05

Oct 5, 2017 ... the mass range of W/Z boson) and also explore the possibility of three-particle BSM final state mimicking diboson excess. .... electron and muon and /ET > 350 GeV are removed. ..... Energy Phys.1510, 076 (2015), arXiv:1506.06767 [hep- ph] .... [15] A Belyaev, N D Christensen and A Pukhov, Comput. Phys.

Attachment and social networks.

Science.gov (United States)

Gillath, Omri; C Karantzas, Gery; Lee, Juwon

2018-02-21

The current review covers two lines of research linking attachment and social networks. One focuses on attachment networks (the people who fulfill one's attachment needs), examining composition and age-related differences pertaining to these networks. The other line integrates attachment with social network analysis to investigate how individual differences in adult attachment are associated with the management and characteristics (e.g., density, multiplexity, and centrality) of people's social networks. We show that most people's attachment networks are small and hierarchical, with one figure being the primary attachment figure (often a mother or romantic partner, depending on age). Furthermore, attachment style predicts network characteristics and management, such that insecurity is associated with less closeness, multiplexity, centrality, and poorer management (less maintenance, more dissolution). Copyright © 2018 Elsevier Ltd. All rights reserved.

Damage of DNA by Low Energy Electrons (< 3 eV)

International Nuclear Information System (INIS)

Bald, Ilko; Illenberger, Eugen; Kopyra, Janina

2012-01-01

Recent experiments on low energy electron attachment to DNA and its components in the condensed phase and in the gas phase are reviewed and analysed. From different condensed phase experiments the sensitivity of DNA towards low energy electrons is well documented and strand breaks in DNA are observed at subexcitation energies (< 3 eV) and also in ultrafast electron transfer experiments involving electrons in presolvated states. Gas phase experiments indicate that all building blocks of DNA (the nucleobases, the sugar and the phosphate moiety) undergo resonant dissociative electron attachment (DEA) in the subexcitation regime which may ultimately lead to strand breaks. From very recent gas phase experiments on an entire nucleotide it can be concluded that most strand breaks result from direct electron attachment to the DNA backbone, but also initial electron capture by the nucleobase following electron transfer to the backbone contributes.

Viii. Attachment and sleep among toddlers: disentangling attachment security and dependency.

Science.gov (United States)

Bélanger, Marie-Ève; Bernier, Annie; Simard, Valérie; Bordeleau, Stéphanie; Carrier, Julie

2015-03-01

Many scholars have proposed that parent-child attachment security should favor child sleep. Research has yet, however, to provide convincing support for this hypothesis. The current study used objective measures of sleep and attachment to assess the longitudinal links between mother-child attachment security and subsequent sleep, controlling for child dependency. Sixty-two middle-class families (30 girls) were met twice, when children were 15 months (Wave 1; W1) and 2 years of age (Wave 2; W2). At W1, mother-child attachment was assessed with the observer version of the Attachment Q-Sort. At W2, children wore an actigraph monitor for 72 hr. Results indicated that children more securely attached to their mothers subsequently slept more at night and had higher sleep efficiency, and these predictions were not confounded by child dependency. These findings suggest a unique role for secure attachment relationships in the development of young children's sleep regulation, while addressing methodological issues that have long precluded consensus in this literature. © 2015 The Society for Research in Child Development, Inc.

Hostility among adolescents in Switzerland? multivariate relations between excessive media use and forms of violence.

Science.gov (United States)

Kuntsche, Emmanuel N

2004-03-01

To determine what kind of violence-related behavior or opinion is directly related to excessive media use among adolescents in Switzerland. A national representative sample of 4222 schoolchildren (7th- and 8th-graders; mean age 13.9 years) answered questions on the frequency of television-viewing, electronic game-playing, feeling unsafe at school, bullying others, hitting others, and fighting with others, as part of the Health Behaviour in School-Aged Children (HBSC) international collaborative study protocol. The Chi-square tests and multiple logistic regression analyses were applied to high-risk groups of adolescents. For the total sample, all bivariate relationships between television-viewing/electronic game-playing and each violence-related variable are significant. In the multivariate comparison, physical violence among boys ceases to be significant. For girls, only television-viewing is linked to indirect violence. Against the hypothesis, females' electronic game-playing only had a bearing on hitting others. Experimental designs are needed that take into account gender, different forms of media, and violence to answer the question of whether excessive media use leads to violent behavior. With the exception of excessive electronic game-playing among girls, this study found that electronic media are not thought to lead directly to real-life violence but to hostility and indirect violence.

An experimental evaluation of the State Adult Attachment Measure: The Influence of Attachment Primes on the Content of State Attachment Representations

OpenAIRE

Bosmans, Guy; Bowles, David, P.; Dewitte, Marieke; De Winter, Simon; Braet, Caroline

2014-01-01

Attachment theory predicts cross-contextual stability of attachment representations, but research findings are rather mixed. Recently, it has been suggested that these mixed findings reflect the existence of both state and trait attachment components. The development of the State Adult Attachment Measure (SAAM) has enabled an investigation of this hypothesis. The current study aimed to evaluate the extent to which the SAAM is a useful instrument for studying such state attachment hypotheses. ...

Attachment over Time.

Science.gov (United States)

Lewis, Michael; Feiring, Candice; Rosenthal, Saul

2000-01-01

Examined continuity in attachment classification from infancy through adolescence and related it to autobiographical memories of childhood, divorce, and maladjustment in white middle-class children. Found no continuity in attachment classification from 1 to 18 years and no relation between infant attachment status and adolescent adjustment.…

Single-wall carbon nanotube chemical attachment at platinum electrodes

International Nuclear Information System (INIS)

Rosario-Castro, Belinda I.; Contes-de-Jesus, Enid J.; Lebron-Colon, Marisabel; Meador, Michael A.; Scibioh, M. Aulice; Cabrera, Carlos R.

2010-01-01

Self-assembled monolayer (SAM) techniques were used to adsorb 4-aminothiophenol (4-ATP) on platinum electrodes in order to obtain an amino-terminated SAM as the base for the chemical attachment of single-wall carbon nanotubes (SWCNTs). A physico-chemical, morphological and electrochemical characterizations of SWCNTs attached onto the modified Pt electrodes was done by using reflection-absorption infrared spectroscopy (RAIR), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), and cyclic voltammetry (CV) techniques. The SWNTs/4-ATP/Pt surface had regions of small, medium, and large thickness of carbon nanotubes with heights of 100-200 nm, 700 nm to 1.5 μm, and 1.0-3.0 μm, respectively. Cyclic voltammetries (CVs) in sulfuric acid demonstrated that attachment of SWNTs on 4-ATP/Pt is markedly stable, even after 30 potential cycles. CV in ruthenium hexamine was similar to bare Pt electrodes, suggesting that SWNTs assembly is similar to a closely packed microelectrode array.

Mechanics of membrane-cytoskeleton attachment in Paramecium

Science.gov (United States)

Campillo, C.; Jerber, J.; Fisch, C.; Simoes-Betbeder, M.; Dupuis-Williams, P.; Nassoy, P.; Sykes, C.

2012-12-01

In this paper we assess the role of the protein MKS1 (Meckel syndrome type 1) in the cortical membrane mechanics of the ciliated protist Paramecium. This protein is known to be crucial in the process of cilium formation, and we investigate its putative role in membrane-cytoskeleton attachment. Therefore, we compare cells where the gene coding for MKS1 is silenced to wild-type cells. We found that scanning electron microscopy observation of the cell surface reveals a cup-like structure in wild-type cells that is lost in silenced cells. Since this structure is based on the underlying cytoskeleton, one hypothesis to explain this observation is a disruption of membrane attachment to the cytoskeleton in the absence of MKS1 that should affect plasma membrane mechanics. We test this by probing the mechanics of wild-type and silenced cells by micropipette aspiration. Strikingly, we observe that, at the same aspiration pressure, the membrane of silenced cells is easily aspirated by the micropipette whereas that of wild-type cells enters only at a moderate velocity, an effect that suggests a detachment of the membrane from the underlying cytoskeleton in silenced cells. We quantify this detachment by measuring the deformation of the cell cortex and the rate of cell membrane entry in the micropipette. This study offers a new perspective for the characterization of membrane-cytoskeleton attachment in protists and paves the way for a better understanding of the role of membrane-cortex attachment in cilium formation.

Systemic therapy and attachment narratives: Attachment Narrative Therapy.

Science.gov (United States)

Dallos, Rudi; Vetere, Arlene

2014-10-01

This article outlines an integration of attachment theory with narrative theory and systemic theory and practice: Attachment Narrative Therapy (ANT). This integration offers a more powerful explanatory formulation of the development and maintenance of human distress in relationships, families and communities, and gives direction to psychotherapeutic intervention. © The Author(s) 2014.

Surface and protein analyses of normal human cell attachment on PIII-modified chitosan membranes

International Nuclear Information System (INIS)

Saranwong, N.; Inthanon, K.; Wongkham, W.; Wanichapichart, P.; Suwannakachorn, D.; Yu, L.D.

2012-01-01

Surface of chitosan membrane was modified with argon (Ar) and nitrogen (N) plasma immersion ion implantation (PIII) for human skin fibroblasts F1544 cell attachment. The modified surfaces were characterized by Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). Cell attachment patterns were evaluated by scanning electron microscopy (SEM). The enzyme-linked immunosorbent assay (ELISA) was used to quantify levels of focal adhesion kinase (FAK). The results showed that Ar PIII had an enhancement effect on the cell attachment while N-PIII had an inhibition effect. Filopodial analysis revealed more microfilament cytoplasmic spreading on the edge of cells attached on the Ar-treated membranes than N-treated membranes. Higher level FAK was found in Ar-treated membranes than that in N-treated membranes.

Scanning electron microscopy

Energy Technology Data Exchange (ETDEWEB)

Cox, B. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

1970-05-15

The JSM-11 scanning electron microscope at CRNL has been used extensively for topographical studies of oxidized metals, fracture surfaces, entomological and biological specimens. A non-dispersive X-ray attachment permits the microanalysis of the surface features. Techniques for the production of electron channeling patterns have been developed. (author)

Excessive Daytime Sleepiness

Directory of Open Access Journals (Sweden)

Yavuz Selvi

2016-06-01

Full Text Available Excessive daytime sleepiness is one of the most common sleep-related patient symptoms, with preva-lence in the community estimated to be as high as 18%. Patients with excessive daytime sleepiness may exhibit life threatening road and work accidents, social maladjustment, decreased academic and occupational performance and have poorer health than comparable adults. Thus, excessive daytime sleepiness is a serious condition that requires investigation, diagnosis and treatment primarily. As with most medical condition, evaluation of excessive daytime sleepiness begins a precise history and various objective and subjective tools have been also developed to assess excessive daytime sleepiness. The most common causes of excessive daytime sleepiness are insufficient sleep hygiene, chronic sleep deprivation, medical and psychiatric conditions and sleep disorders, such as obstructive sleep apnea, medications, and narcolepsy. Treatment option should address underlying contributors and promote sleep quantity by ensuring good sleep hygiene. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2016; 8(2: 114-132

Infant attachment, adult attachment, and maternal sensitivity: revisiting the intergenerational transmission gap.

Science.gov (United States)

Behrens, Kazuko Y; Haltigan, John D; Bahm, Naomi I Gribneau

2016-08-01

This study investigated the intergenerational transmission of attachment, utilizing the Adult Attachment Interview (AAI), the Strange Situation Procedure (SSP), and the Maternal Behavioral Q-Set (MBQS). We revisited fundamental questions in attachment theory and research by examining: (1) the level of intergenerational agreement between maternal attachment representations and infant attachment security, and (2) whether maternal sensitivity serves as an intergenerational mediator between adult and infant attachment security. Significant categorical matches between the AAI and the SSP as well as mean differences for MBQS scores between adult attachment secure-insecure groups were found. Consistent with earlier intergenerational research, maternal sensitivity only partially mediated the AAI-SSP link, indicating the transmission gap remains. Consistent with recent mediation studies, using more contemporary analytical techniques, it was confirmed that maternal sensitivity did mediate the direct pathway between AAI security and SSP security. Thus, the transmission gap appears somewhat different depending on the statistical method used to measure mediation. Post hoc analyses considered mothers' childhood experiences of separation/divorce and this helped make sense of intergenerational mismatches.

The interaction of low-energy electrons with fructose molecules

Science.gov (United States)

Chernyshova, I. V.; Kontrosh, E. E.; Markush, P. P.; Shpenik, O. B.

2017-11-01

Using a hypocycloidal electronic spectrometer, the interactions of low energy electrons (0-8.50 eV) with fructose molecules, namely, electron scattering and dissociative attachment, are studied. The results of these studies showed that the fragmentation of fructose molecules occurs effectively even at an electron energy close to zero. In the total electron-scattering cross section by molecules, resonance features (at energies 3.10 and 5.00 eV) were first observed near the formation thresholds of light ion fragments OH- and H-. The correlation of the features observed in the cross sections of electron scattering and dissociative attachment is analyzed.

Attachment and children's biased attentional processing: evidence for the exclusion of attachment-related information.

Directory of Open Access Journals (Sweden)

Eva Vandevivere

Full Text Available Research in both infants and adults demonstrated that attachment expectations are associated with the attentional processing of attachment-related information. However, this research suffered from methodological issues and has not been validated across ages. Employing a more ecologically valid paradigm to measure attentional processes by virtue of eye tracking, the current study tested the defensive exclusion hypothesis in late childhood. According to this hypothesis, insecurely attached children are assumed to defensively exclude attachment-related information. We hypothesized that securely attached children process attachment- related neutral and emotional information in a more open manner compared to insecurely attached children. Sixty-two children (59.7% girls, 8-12 years completed two different tasks, while eye movements were recorded: task one presented an array of neutral faces including mother and unfamiliar women and task two presented the same with happy and angry faces. Results indicated that more securely attached children looked longer at mother's face regardless of the emotional expression. Also, they tend to have more maintained attention to mother's neutral face. Furthermore, more attachment avoidance was related to a reduced total viewing time of mother's neutral, happy, and angry face. Attachment anxiety was not consistently related to the processing of mother's face. Findings support the theoretical assumption that securely attached children have an open manner of processing all attachment-related information.

Theory of long-range interactions for Rydberg states attached to hyperfine-split cores

Science.gov (United States)

Robicheaux, F.; Booth, D. W.; Saffman, M.

2018-02-01

The theory is developed for one- and two-atom interactions when the atom has a Rydberg electron attached to a hyperfine-split core state. This situation is relevant for some of the rare-earth and alkaline-earth atoms that have been proposed for experiments on Rydberg-Rydberg interactions. For the rare-earth atoms, the core electrons can have a very substantial total angular momentum J and a nonzero nuclear spin I . In the alkaline-earth atoms there is a single (s ) core electron whose spin can couple to a nonzero nuclear spin for odd isotopes. The resulting hyperfine splitting of the core state can lead to substantial mixing between the Rydberg series attached to different thresholds. Compared to the unperturbed Rydberg series of the alkali-metal atoms, the series perturbations and near degeneracies from the different parity states could lead to qualitatively different behavior for single-atom Rydberg properties (polarizability, Zeeman mixing and splitting, etc.) as well as Rydberg-Rydberg interactions (C5 and C6 matrices).

The Attachment Imperative

DEFF Research Database (Denmark)

Navne, Laura Emdal; Svendsen, Mette Nordahl; Gammeltoft, Tine

2017-01-01

on social relations and point to the productive aspects of practices of distance and detachment. We show that while the NICU upholds an imperative of attachment independently of the infant's chances of survival, for parents, attachment is contingent on certain hesitations in relation to their infant. We...... argue that there are nuances in practices of relationmaking in need of more attention (i.e., the nexus of attachment and detachment). Refraining from touching, holding, and feeding their infants during critical periods, the parents enact detachment as integral to their practices of attachment....... Such “cuts” in parent–infant relations become steps on the way to securing the infant's survival and making kin(ship). We conclude that although infants may be articulated as “maybe‐lives” by staff, in the NICU as well as in Danish society, the ideal of attachment appears to leave little room for “maybe‐parents.”...

The Structural Model in Parenting Style, Attachment Style, Self-regulation and Self-esteem for Smartphone Addiction

OpenAIRE

Kwan Hoi Ching; Leung Man Tak

2017-01-01

Excessive smartphone usage has become a highly controversial and substantial worldwide issue. This paper explores the complexities and challenges of smartphone addiction with a particular focus on parenting styles, attachment, and self-regulation. Convenience sampling was used to gather data from 211 university students in Hong Kong (138 females/74 males) through their responses to four questionnaires. One structural equation model was formed successfully which indicated that parenting style ...

The process of developing and changing of infant-teacher attachment : A study on an infant whose attachment to the first attachment figure is insecure

OpenAIRE

上田, 七生

2003-01-01

Toward infants whose attachment to their first attachment figures (mainly their mothers) is insecure, how can we intervene in them? To reveal it, an observation was carried out regularly once a week, over a period of 9 months. The subjects were an infant who has insecure attachment and comparative one who has secure attachment. And the attachment behaviors they exhibited toward nursery school teachers, strangers, and an observer were counted. The amount of the attachment behaviors of the infa...

Mechanics of membrane–cytoskeleton attachment in Paramecium

International Nuclear Information System (INIS)

Campillo, C; Nassoy, P; Sykes, C; Jerber, J; Fisch, C; Dupuis-Williams, P; Simoes-Betbeder, M

2012-01-01

In this paper we assess the role of the protein MKS1 (Meckel syndrome type 1) in the cortical membrane mechanics of the ciliated protist Paramecium. This protein is known to be crucial in the process of cilium formation, and we investigate its putative role in membrane–cytoskeleton attachment. Therefore, we compare cells where the gene coding for MKS1 is silenced to wild-type cells. We found that scanning electron microscopy observation of the cell surface reveals a cup-like structure in wild-type cells that is lost in silenced cells. Since this structure is based on the underlying cytoskeleton, one hypothesis to explain this observation is a disruption of membrane attachment to the cytoskeleton in the absence of MKS1 that should affect plasma membrane mechanics. We test this by probing the mechanics of wild-type and silenced cells by micropipette aspiration. Strikingly, we observe that, at the same aspiration pressure, the membrane of silenced cells is easily aspirated by the micropipette whereas that of wild-type cells enters only at a moderate velocity, an effect that suggests a detachment of the membrane from the underlying cytoskeleton in silenced cells. We quantify this detachment by measuring the deformation of the cell cortex and the rate of cell membrane entry in the micropipette. This study offers a new perspective for the characterization of membrane–cytoskeleton attachment in protists and paves the way for a better understanding of the role of membrane–cortex attachment in cilium formation. (paper)

The galactic center GeV excess from a series of leptonic cosmic-ray outbursts

Energy Technology Data Exchange (ETDEWEB)

Cholis, Ilias [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Evoli, Carmelo [Univ. Hamburg, Hamburg (Germany); Calore, Francesca [Univ. of Amsterdam, Amsterdam (Netherlands); Linden, Tim [Univ. of Chicago, Chicago, IL (United States); Weniger, Christoph [Univ. of Amsterdam, Amsterdam (Netherlands); Hooper, Dan [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Univ. of Chicago, Chicago, IL (United States)

2015-06-16

It has been proposed that a recent outburst of cosmic-ray electrons could account for the excess of GeV-scale gamma rays observed from the region surrounding the Galactic Center. After studying this possibility in some detail, we identify scenarios in which a series of leptonic cosmic-ray outbursts could plausibly generate the observed excess. The morphology of the emission observed outside of ~1° – 2° from the Galactic Center can be accommodated with two outbursts, one which took place approximately ~10⁶ years ago, and another (injecting only about 10% as much energy as the first) about ~10⁵ years ago. The emission observed from the innermost ~1° – 2° requires one or more additional recent outbursts and/or a contribution from a centrally concentrated population of unresolved millisecond pulsars. Furthermore, in order to produce a spectrum that is compatible with the measured excess (whose shape is approximately uniform over the region of the excess), the electrons from the older outburst must be injected with significantly greater average energy than those injected more recently, enabling their spectra to be similar after ~10⁶ years of energy losses.

The relation of infant attachment to attachment and cognitive and behavioural outcomes in early childhood.

Science.gov (United States)

Ding, Yan-hua; Xu, Xiu; Wang, Zheng-yan; Li, Hui-rong; Wang, Wei-ping

2014-09-01

In China, research on the relation of mother-infant attachment to children's development is scarce. This study sought to investigate the relation of mother-infant attachment to attachment, cognitive and behavioural development in young children. This study used a longitudinal study design. The subjects included healthy infants (n=160) aged 12 to 18 months. Ainsworth's "Strange Situation Procedure" was used to evaluate mother-infant attachment types. The attachment Q-set (AQS) was used to evaluate the attachment between young children and their mothers. The Bayley scale of infant development-second edition (BSID-II) was used to evaluate cognitive developmental level in early childhood. Achenbach's child behaviour checklist (CBCL) for 2- to 3-year-olds was used to investigate behavioural problems. In total, 118 young children (73.8%) completed the follow-up; 89.7% of infants with secure attachment and 85.0% of infants with insecure attachment still demonstrated this type of attachment in early childhood (κ=0.738, pInfants with insecure attachment collectively exhibited a significantly lower mental development index (MDI) in early childhood than did infants with secure attachment, especially the resistant type. In addition, resistant infants were reported to have greater social withdrawal, sleep problems and aggressive behaviour in early childhood. There is a high consistency in attachment development from infancy to early childhood. Secure mother-infant attachment predicts a better cognitive and behavioural outcome; whereas insecure attachment, especially the resistant attachment, may lead to a lower cognitive level and greater behavioural problems in early childhood. Copyright © 2014 Elsevier Ltd. All rights reserved.

Electron-induced chemistry in microhydrated sulfuric acid clusters

Science.gov (United States)

Lengyel, Jozef; Pysanenko, Andriy; Fárník, Michal

2017-11-01

We investigate the mixed sulfuric acid-water clusters in a molecular beam experiment with electron attachment and negative ion mass spectrometry and complement the experiment by density functional theory (DFT) calculations. The microhydration of (H2SO4)m(H2O)n clusters is controlled by the expansion conditions, and the electron attachment yields the main cluster ion series (H2SO4)m(H2O)nHSO4- and (H2O)nH2SO4-. The mass spectra provide an experimental evidence for the onset of the ionic dissociation of sulfuric acid and ion-pair (HSO4- ṡ ṡ ṡ H3O+) formation in the neutral H2SO4(H2O)n clusters with n ≥ 5 water molecules, in excellent agreement with the theoretical predictions. In the clusters with two sulfuric acid molecules (H2SO4)2(H2O)n this process starts as early as n ≥ 2 water molecules. The (H2SO4)m(H2O)nHSO4- clusters are formed after the dissociative electron attachment to the clusters containing the (HSO4- ṡ ṡ ṡ H3O+) ion-pair structure, which leads to the electron recombination with the H3O+ moiety generating H2O molecule and the H-atom dissociation from the cluster. The (H2O)nH2SO4- cluster ions point to an efficient caging of the H atom by the surrounding water molecules. The electron-energy dependencies exhibit an efficient electron attachment at low electron energies below 3 eV, and no resonances above this energy, for all the measured mass peaks. This shows that in the atmospheric chemistry only the low-energy electrons can be efficiently captured by the sulfuric acid-water clusters and converted into the negative ions. Possible atmospheric consequences of the acidic dissociation in the clusters and the electron attachment to the sulfuric acid-water aerosols are discussed.

Sentence-Level Attachment Prediction

Science.gov (United States)

Albakour, M.-Dyaa; Kruschwitz, Udo; Lucas, Simon

Attachment prediction is the task of automatically identifying email messages that should contain an attachment. This can be useful to tackle the problem of sending out emails but forgetting to include the relevant attachment (something that happens all too often). A common Information Retrieval (IR) approach in analyzing documents such as emails is to treat the entire document as a bag of words. Here we propose a finer-grained analysis to address the problem. We aim at identifying individual sentences within an email that refer to an attachment. If we detect any such sentence, we predict that the email should have an attachment. Using part of the Enron corpus for evaluation we find that our finer-grained approach outperforms previously reported document-level attachment prediction in similar evaluation settings.

Recent progress in the theory of dissociative attachment: From diatomics to biomolecules

International Nuclear Information System (INIS)

Fabrikant, Ilya I

2010-01-01

We present a summary of recent progress in theoretical studies of low-energy dissociative electron attachment (DEA) to halogen molecules and polyatomic molecules based on the resonance R-matrix theory. It explains many observed features in DEA cross sections including low-energy behavior, threshold resonances and cusps. It also gives correct description of the temperature dependence of the attachment rate coefficients. More recently the theory was applied to two molecules of biological interest, formic acid and glycine. DEA mechanisms in these systems are very similar to those in hydrogen halides.

‘Excess’ of primary cosmic ray electrons

Directory of Open Access Journals (Sweden)

Xiang Li

2015-10-01

Full Text Available With the accurate cosmic ray (CR electron and positron spectra (denoted as Φe− and Φe+, respectively measured by AMS-02 Collaboration, the difference between the electron and positron fluxes (i.e., ΔΦ=Φe−−Φe+, dominated by the propagated primary electrons, can be reliably inferred. In the standard model, the spectrum of propagated primary CR electrons at energies ≥30GeV softens with the increase of energy. The absence of any evidence for such a continuous spectral softening in ΔΦ strongly suggests a significant ‘excess’ of primary CR electrons and at energies of 100–400GeV the identified excess component has a flux comparable to that of the observed positron excess. Middle-age but ‘nearby’ supernova remnants (e.g., Monogem and Geminga are favored sources for such an excess.

Belt attachment and system

Energy Technology Data Exchange (ETDEWEB)

Schneider, Abraham D.; Davidson, Erick M.

2018-03-06

Disclosed herein is a belt assembly including a flexible belt with an improved belt attachment. The belt attachment includes two crossbars spaced along the length of the belt. The crossbars retain bearings that allow predetermined movement in six degrees of freedom. The crossbars are connected by a rigid body that attaches to the bearings. Implements that are attached to the rigid body are simply supported but restrained in pitching rotation.

Clinical decision - making review on magnetic attachments versus mechanical attachments in dental prosthetics

Directory of Open Access Journals (Sweden)

Francesca Fabiano

2017-11-01

Full Text Available Background Conventional dentures in edentulous patients show some limitations due to the lack of retention, support and stability thus resulting in difficulty to chew. The modern implantology allows to use different implant overdentures and different attachment systems. The selection of the attachment by practitioners is mainly influenced by the clinical experience or technical preferences. Aims The aim of the present review is to provide an adequate background to the clinicians, in order to select the prosthetic attachments according to the current literature. The mechanical attachments have been compared to the magnetic devices, with the aim to guide the decision of the practitioners. Methods Articles topics selection was based on the use of magnetic attachments in dentistry and the comparison between them and mechanical connectors. The databases used were PubMed/MEDLINE, Google Scholar and ISI Web of Science. A critical evaluation of the selected paper has been made to choose the ones that matched the inclusion criteria. Results Nowadays, few studies have compared different attachments in a manner useful for clinical decision-making. The main problem limiting long-term durability of magnetic attachments in the oral fluid is the poor corrosion resistance of permanent magnets and the consequent leaching of cytotoxic ions. Conclusion Magnetic attachments in comparison with other attaching systems can be useful in patients with special needs, in patients with limited interocclusal space, or in patients with neuromuscular limitations, thanks to the automatic reseating properties. However, it’s important to highlight that the mechanical attachments still represent the best choice in common conditions requiring dental prostheses.

Neutralization of Rubidium Adsorbate Electric Fields by Electron Attachment

Energy Technology Data Exchange (ETDEWEB)

Sedlacek, J. A. [Univ. of Oklahoma, Norman, OK (United States); Kim, E. [Univ. of Nevada, Las Vegas, NV (United States); Rittenhouse, S. T. [Western Washington Univ., Bellingham, WA (United States); US Naval Academy, Annapolis, MD (United States); Weck, Philippe F [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sadeghpour, H. R. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Shaffer, J. P. [Univ. of Oklahoma, Norman, OK (United States)

2015-10-01

We investigate the (0001) surface of single crystal quartz with a submonolayer of Rb adsorbates. Using Rydberg atom electromagnetically induced transparency, we investigate the electric elds resulting from Rb adsorbed on the quartz surface, and measure the activation energy of the Rb adsorbates. We show that the Rb induces a negative electron affnity (NEA) on the quartz surface. The NEA surface allows for low energy electrons to bind to the surface and cancel the electric eld from the Rb adsorbates. Our results have implications for integrating Rydberg atoms into hybrid quantum systems and the fundamental study of atom-surface interactions, as well as applications for electrons bound to a 2D surface.

On the applicability of one- and many-electron quantum chemistry models for hydrated electron clusters

Science.gov (United States)

Turi, László

2016-04-01

We evaluate the applicability of a hierarchy of quantum models in characterizing the binding energy of excess electrons to water clusters. In particular, we calculate the vertical detachment energy of an excess electron from water cluster anions with methods that include one-electron pseudopotential calculations, density functional theory (DFT) based calculations, and ab initio quantum chemistry using MP2 and eom-EA-CCSD levels of theory. The examined clusters range from the smallest cluster size (n = 2) up to nearly nanosize clusters with n = 1000 molecules. The examined cluster configurations are extracted from mixed quantum-classical molecular dynamics trajectories of cluster anions with n = 1000 water molecules using two different one-electron pseudopotenial models. We find that while MP2 calculations with large diffuse basis set provide a reasonable description for the hydrated electron system, DFT methods should be used with precaution and only after careful benchmarking. Strictly tested one-electron psudopotentials can still be considered as reasonable alternatives to DFT methods, especially in large systems. The results of quantum chemistry calculations performed on configurations, that represent possible excess electron binding motifs in the clusters, appear to be consistent with the results using a cavity structure preferring one-electron pseudopotential for the hydrated electron, while they are in sharp disagreement with the structural predictions of a non-cavity model.

On the applicability of one- and many-electron quantum chemistry models for hydrated electron clusters

Energy Technology Data Exchange (ETDEWEB)

Turi, László, E-mail: turi@chem.elte.hu [Department of Physical Chemistry, Eötvös Loránd University, P.O. Box 32, H-1518 Budapest 112 (Hungary)

2016-04-21

We evaluate the applicability of a hierarchy of quantum models in characterizing the binding energy of excess electrons to water clusters. In particular, we calculate the vertical detachment energy of an excess electron from water cluster anions with methods that include one-electron pseudopotential calculations, density functional theory (DFT) based calculations, and ab initio quantum chemistry using MP2 and eom-EA-CCSD levels of theory. The examined clusters range from the smallest cluster size (n = 2) up to nearly nanosize clusters with n = 1000 molecules. The examined cluster configurations are extracted from mixed quantum-classical molecular dynamics trajectories of cluster anions with n = 1000 water molecules using two different one-electron pseudopotenial models. We find that while MP2 calculations with large diffuse basis set provide a reasonable description for the hydrated electron system, DFT methods should be used with precaution and only after careful benchmarking. Strictly tested one-electron psudopotentials can still be considered as reasonable alternatives to DFT methods, especially in large systems. The results of quantum chemistry calculations performed on configurations, that represent possible excess electron binding motifs in the clusters, appear to be consistent with the results using a cavity structure preferring one-electron pseudopotential for the hydrated electron, while they are in sharp disagreement with the structural predictions of a non-cavity model.

ATTACHMENT AND TRANSFER

OpenAIRE

Pasare, Daniela

2011-01-01

Bowlby's concept of attachment and Freud's concept of transference are two of the most influential theories of how we construct mental representations of human relationships. The attachment’s theory offers one more strategy for the therapeutic approach. Factors that lead to a secure attachment between mother and child may also be applied to the relationship between patient and psychotherapist. Psychotherapy may help a patient create himself new attachment and relationship patterns. Creating a...

Attachment is a dynamic system

Directory of Open Access Journals (Sweden)

Zlatka Cugmas

2003-04-01

Full Text Available On the basis of the study of recent scientific literature about the development of attachment, the author answers the following questions: which are the postulates the theory of attachment has about the stability of the patterns of attachment, which level of stability in the patterns of attachment from infancy to adulthood these studies illuminate and which factors significantly influence the (instability of the patterns of attachment in time. The theory of attachment assumes that normal circumstances elicit stability. Changes, however, can be the result of important events influencing the sensitivity of the object of attachment. Agreement has not yet been reached regarding the percentage of stability in the patterns of attachment. There is more agreement regarding attachment in adulthood than that in childhood. The results depend on the size and characteristics of the subjects of the research, the measuring instruments, type of data analysis etc. The author concludes that attachment is a dynamic system influenced by significant changes in life (the cognitive development of the child, external care, parents' divorce, different stressful situations. As the influence of stressful events on the individual person' s quality of attachment is examined, it is necessary to consider also his/her temperamental characteristics, role of other people in their lives, etc.

Phonon excess heating in electronic relaxation theory in quantum dots

Czech Academy of Sciences Publication Activity Database

Král, Karel; Lin, Ch. Y.

2008-01-01

Roč. 22, č. 20 (2008), s. 3439-3460 ISSN 0217-9792 R&D Projects: GA MŠk ME 866 Institutional research plan: CEZ:AV0Z10100520 Keywords : quantum dots * electron -phonon interaction * electron ic transport Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.558, year: 2008

The Multimodal Assessment of Adult Attachment Security: Developing the Biometric Attachment Test.

Science.gov (United States)

Parra, Federico; Miljkovitch, Raphaële; Persiaux, Gwenaelle; Morales, Michelle; Scherer, Stefan

2017-04-06

Attachment theory has been proven essential for mental health, including psychopathology, development, and interpersonal relationships. Validated psychometric instruments to measure attachment abound but suffer from shortcomings common to traditional psychometrics. Recent developments in multimodal fusion and machine learning pave the way for new automated and objective psychometric instruments for adult attachment that combine psychophysiological, linguistic, and behavioral analyses in the assessment of the construct. The aim of this study was to present a new exposure-based, automatic, and objective adult-attachment assessment, the Biometric Attachment Test (BAT), which exposes participants to a short standardized set of visual and music stimuli, whereas their immediate reactions and verbal responses, captured by several computer sense modalities, are automatically analyzed for scoring and classification. We also aimed to empirically validate two of its assumptions: its capacity to measure attachment security and the viability of using themes as placeholders for rotating stimuli. A total of 59 French participants from the general population were assessed using the Adult Attachment Questionnaire (AAQ), the Adult Attachment Projective Picture System (AAP), and the Attachment Multiple Model Interview (AMMI) as ground truth for attachment security. They were then exposed to three different BAT stimuli sets, whereas their faces, voices, heart rate (HR), and electrodermal activity (EDA) were recorded. Psychophysiological features, such as skin-conductance response (SCR) and Bayevsky stress index; behavioral features, such as gaze and facial expressions; as well as linguistic and paralinguistic features, were automatically extracted. An exploratory analysis was conducted using correlation matrices to uncover the features that are most associated with attachment security. A confirmatory analysis was conducted by creating a single composite effects index and by testing it

Measuring Patients’ Attachment Avoidance in Psychotherapy: Development of the Attachment Avoidance in Therapy Scale (AATS

Directory of Open Access Journals (Sweden)

András Láng

2012-11-01

Full Text Available A new scale measuring patient-therapist attachment avoidance was developed. Attachment Avoidance in Therapy Scale is a new measure based on the Bartholomew model of adult attachment (Bartholomew & Horowitz, 1991 and the Experience in Close Relationships Scale (Brennan, Clark, & Shaver, 1998 to measure patients’ attachment avoidance towards therapists. With 112 patient-therapist dyads participating in the study, validation of a preliminary scale – measuring both attachment anxiety and attachment avoidance in therapy – took place using therapists’ evaluations of patients’ relational behavior and patients’ self-reports about their attitude toward psychotherapy. Analysis of the data revealed six underlying scales. Results showed all six scales to be reliable. Validation of scales measuring attachment anxiety failed. The importance of Attachment Avoidance in Therapy Scale and its subscales is discussed.

Trapped electron decay by the thermally-assisted tunnelling to electron acceptors in glassy matrices. A computer simulation study

International Nuclear Information System (INIS)

Feret, B.; Bartczak, W.M.; Kroh, J.

1991-01-01

The Redi-Hopefield quantum mechanical model of the thermally-assisted electron transfer has been applied to simulate the decay of trapped electrons by tunnelling to electron acceptor molecules added to the glassy matrix. It was assumed that the electron energy levels in donors and acceptors are statistically distributed and the electron excess energy after transfer is dissipated in the medium by the electron-phonon coupling. The electron decay curves were obtained by the method of computer simulation. It was found that for a given medium there exists a certain preferred value of the electronic excess energy which can be effectively converted into the matrix vibrations. If the mismatch of the electron states on the donor and acceptor coincides with the ''resonance'' energy the overall kinetics of electron transfer is accelerated. (author)

On energetic prerequisites of attracting electrons

Energy Technology Data Exchange (ETDEWEB)

Sundholm, Dage [Department of Chemistry, POB 55 (A.I. Virtanens plats 1), FIN-00014 University of Helsinki (Finland)

2014-06-21

The internal reorganization energy and the zero-point vibrational energy (ZPE) of fractionally charged molecules embedded in molecular materials are discussed. The theory for isolated open quantum systems is taken as the starting point. It is shown that for isolated molecules the internal reorganization-energy function and its slope, i.e., the chemical potential of an open molecular system are monotonically decreasing functions with respect to increasing amount of negative excess charge (q) in the range of q = [0, 1]. Calculations of the ZPE for fractionally charged molecules show that the ZPE may have a minimum for fractional occupation. The calculations show that the internal reorganization energy and changes in the ZPE are of the same order of magnitude with different behavior as a function of the excess charge. The sum of the contributions might favor molecules with fractional occupation of the molecular units and partial delocalization of the excess electrons in solid-state materials also when considering Coulomb repulsion between the excess electrons. The fractional electrons are then coherently distributed on many molecules of the solid-state material forming a condensate of attracting electrons, which is crucial for the superconducting state.

On energetic prerequisites of attracting electrons

Science.gov (United States)

Sundholm, Dage

2014-06-01

The internal reorganization energy and the zero-point vibrational energy (ZPE) of fractionally charged molecules embedded in molecular materials are discussed. The theory for isolated open quantum systems is taken as the starting point. It is shown that for isolated molecules the internal reorganization-energy function and its slope, i.e., the chemical potential of an open molecular system are monotonically decreasing functions with respect to increasing amount of negative excess charge (q) in the range of q = [0, 1]. Calculations of the ZPE for fractionally charged molecules show that the ZPE may have a minimum for fractional occupation. The calculations show that the internal reorganization energy and changes in the ZPE are of the same order of magnitude with different behavior as a function of the excess charge. The sum of the contributions might favor molecules with fractional occupation of the molecular units and partial delocalization of the excess electrons in solid-state materials also when considering Coulomb repulsion between the excess electrons. The fractional electrons are then coherently distributed on many molecules of the solid-state material forming a condensate of attracting electrons, which is crucial for the superconducting state.

On energetic prerequisites of attracting electrons

International Nuclear Information System (INIS)

Sundholm, Dage

2014-01-01

The internal reorganization energy and the zero-point vibrational energy (ZPE) of fractionally charged molecules embedded in molecular materials are discussed. The theory for isolated open quantum systems is taken as the starting point. It is shown that for isolated molecules the internal reorganization-energy function and its slope, i.e., the chemical potential of an open molecular system are monotonically decreasing functions with respect to increasing amount of negative excess charge (q) in the range of q = [0, 1]. Calculations of the ZPE for fractionally charged molecules show that the ZPE may have a minimum for fractional occupation. The calculations show that the internal reorganization energy and changes in the ZPE are of the same order of magnitude with different behavior as a function of the excess charge. The sum of the contributions might favor molecules with fractional occupation of the molecular units and partial delocalization of the excess electrons in solid-state materials also when considering Coulomb repulsion between the excess electrons. The fractional electrons are then coherently distributed on many molecules of the solid-state material forming a condensate of attracting electrons, which is crucial for the superconducting state

Special Attachments. Module 19.

Science.gov (United States)

South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

This module on special attachments, one in a series dealing with industrial sewing machines, their attachments, and operation, covers four topics: gauges; cording attachment; zipper foot; and hemming, shirring, and binding. For each topic these components are provided: an introduction, directions, an objective, learning activities, student…

From security to attachment : Mary Ainsworth's contribution to attachment theory

NARCIS (Netherlands)

Rosmalen, Lenette (Lenny) van

2015-01-01

Even though John Bowlby (1907-1990) is generally regarded as the founder of attachment theory, Mary Ainsworth’s (1913-1999) contribution is considerable and goes beyond the design of the Strange Situation Procedure and the introduction of maternal sensitivity as decisive for a secure attachment

Sexuality examined through the lens of attachment theory: attachment, caregiving, and sexual satisfaction.

Science.gov (United States)

Péloquin, Katherine; Brassard, Audrey; Lafontaine, Marie-France; Shaver, Phillip R

2014-01-01

Attachment researchers have proposed that the attachment, caregiving, and sexual behavioral systems are interrelated in adult love relationships (Mikulincer & Shaver, 2007 ). This study examined whether aspects of partners' caregiving (proximity, sensitivity, control, compulsive caregiving) mediated the association between their attachment insecurities (anxiety and avoidance) and each other's sexual satisfaction in two samples of committed couples (Study 1: 126 cohabiting or married couples from the general community; Study 2: 55 clinically distressed couples). Partners completed the Experiences in Close Relationships measure (Brennan, Clark, & Shaver, 1998 ), the Caregiving Questionnaire (Kunce & Shaver, 1994 ), and the Global Measure of Sexual Satisfaction (Lawrance & Byers, 1998 ). Path analyses based on the actor-partner interdependence model (APIM) revealed that caregiving proximity mediated the association between low attachment avoidance and partners' sexual satisfaction in distressed and nondistressed couples. Sensitivity mediated this association in nondistressed couples only. Control mediated the association between men's insecurities (attachment-related avoidance and anxiety) and their partners' low sexual satisfaction in nondistressed couples. Attachment anxiety predicted compulsive caregiving, but this caregiving dimension was not a significant mediator. These results are discussed in light of attachment theory and their implications for treating distressed couples.

Experimental determination of the electron-avalanche and the electron-ion recombination coefficient

NARCIS (Netherlands)

Ernst, G.J.; Boer, A.G.

1980-01-01

The electron-ion recombination coefficient γ and the avalanche coefficient δ = (α − a) · vd, where α and a are the ionizat ion and attachment coefficients respectively and vd the drift velocity of the electrons, have been experimentally determined in a self-sustained CO2-laser system (1:1:3 mixture)

Effects of Lectins on initial attachment of cariogenic Streptococcus mutans.

Science.gov (United States)

Ito, Takashi; Yoshida, Yasuhiro; Shiota, Yasuyoshi; Ito, Yuki; Yamamoto, Tadashi; Takashiba, Shogo

2018-02-01

Oral bacteria initiate biofilm formation by attaching to tooth surfaces via an interaction of a lectin-like bacterial protein with carbohydrate chains on the pellicle. This study aimed to find naturally derived lectins that inhibit the initial attachment of a cariogenic bacterial species, Streptococcus mutans (S. mutans), to carbohydrate chains in saliva in vitro. Seventy kinds of lectins were screened for candidate motifs that inhibit the attachment of S. mutans ATCC 25175 to a saliva-coated culture plate. The inhibitory effect of the lectins on attachment of the S. mutans to the plates was quantified by crystal violet staining, and the biofilm was observed under a scanning electron microscope (SEM). Surface plasmon resonance (SPR) analysis was performed to examine the binding of S. mutans to carbohydrate chains and the binding of candidate lectins to carbohydrate chains, respectively. Moreover, binding assay between the biotinylated-lectins and the saliva components was conducted to measure the lectin binding. Lectins recognizing a salivary carbohydrate chain, Galβ1-3GalNAc, inhibited the binding of S. mutans to the plate. In particular, Agaricus bisporus agglutinin (ABA) markedly inhibited the binding. This inhibition was confirmed by SEM observation. SPR analysis indicated that S. mutans strongly binds to Galβ1-3GalNAc, and ABA binds to Galβ1-3GalNAc. Finally, the biotinylated Galβ1-3GalNAc-binding lectins including ABA demonstrated marked binding to the saliva components. These results suggest that ABA lectin inhibited the attachment of S. mutans to Galβ1-3GalNAc in saliva and ABA can be useful as a potent inhibitor for initial attachment of oral bacteria and biofilm formation.

Characterization of the aging and excess noise of a Hamamatsu fine mesh photopentode

Energy Technology Data Exchange (ETDEWEB)

Fujimoto, D., E-mail: fujimoto@phas.ubc.ca; Hearty, C., E-mail: hearty@physics.ubc.ca

2016-07-01

The excess noise factor and the aging characteristics of 16 Hamamatsu R11283 photopentodes have been tested. These fine-mesh phototubes are to be paired with pure CsI scintillation crystals considered for use in the endcap calorimeter of the Belle II detector. The average excess noise factor was found to be 1.9±0.1±0.4. The electronic noise of a custom preamplifier produced by the University of Montreal was found as a consequence of this measurement and was 1730±33 electrons, in agreement with previous values. On average, the gain×quantum efficiency was reduced to 92±3% of the initial value after passing an average of 7 C through the anode. This corresponds to 70 years of standard Belle II operation.

Peer attachment, specific patterns of internet use and problematic internet use in male and female adolescents.

Science.gov (United States)

Reiner, Iris; Tibubos, Ana N; Hardt, Jochen; Müller, Kai; Wölfling, Klaus; Beutel, Manfred E

2017-10-01

Problematic internet use may lead to serious psychosocial dysfunction. Recent studies have found comparable prevalence in both male and female adolescents. We pursue the neglected questions how male and female adolescents differ regarding their patterns of internet use and how gender, peer attachment and patterns of use are related to pathological internet use. In 2410 adolescents (1307 girls and 1103 boys) aged 12-18 years from different types of school we assessed peer attachment, frequency and use of eight specific applications and indicators of pathological internet use. Three patterns of internet use, 'social'; 'sex and games" and 'functional' were identified and connections between variables were modeled by ordered sequences of regression. We found that problematic internet use-sex and games as well as social usage-was more prevalent in boys. Insecure peer attachment predicted problematic internet use in both sexes. Also, excessive usage of internet games and sex mediated the influence of peer attachment insecurity on problematic internet use, but only for boys. Our study identified that adolescents with insecure peer attachment are at higher risk for problematic internet use. With regard to specific types of internet use, the consumption of online games and sex was identified as risk factor in boys with increasing age. Further studies are needed to understand and possibly subgroup problematic internet use behavior in girls. Our findings suggest that increasing the quality of peer relationships may be promising approach in the prevention and treatment of problematic internet use.

Disinfection of bacteria attached to granular activated carbon.

Science.gov (United States)

LeChevallier, M W; Hassenauer, T S; Camper, A K; McFeters, G A

1984-01-01

Heterotrophic plate count bacteria, coliform organisms, and pathogenic microorganisms attached to granular activated carbon particles were examined for their susceptibility to chlorine disinfection. When these bacteria were grown on carbon particles and then disinfected with 2.0 mg of chlorine per liter (1.4 to 1.6 mg of free chlorine residual per liter after 1 h) for 1 h, no significant decrease in viable counts was observed. Washed cells attached to the surface of granular activated carbon particles showed similar resistance to chlorine, but a progressive increase in sublethal injury was found. Observations made by scanning electron microscope indicated that granular activated carbon was colonized by bacteria which grow in cracks and crevices and are coated by an extracellular slime layer. These data suggest a possible mechanism by which treatment and disinfection barriers can be penetrated and pathogenic bacteria may enter drinking water supplies. Images PMID:6508306

Structural Interfaces and Attachments in Biology

CERN Document Server

Birman, Victor; Genin, Guy

2013-01-01

Attachment of dissimilar materials in engineering and surgical practice is a perennial challenge. Bimaterial attachment sites are common locations for injury, repeated injury, and mechanical failure. Nature presents several highly effective solutions to the challenge of bimaterial attachment that differ from those found in engineering practice. Structural Interfaces and Attachments in Biology describes the attachment of dissimilar materials from multiple perspectives. The text will simultaneously elucidate natural bimaterial attachments and outline engineering principles underlying successful attachments to the communities of tissue engineers and surgeons. Included an in-depth analysis of the biology of attachments in the body and mechanisms by which robust attachments are formed, a review of current concepts of attaching dissimilar materials in surgical practice and a discussion of bioengineering approaches that are currently being developed. This book also: Provides the first comprehensive treatment of phys...

Electron-induced chemistry in microhydrated sulfuric acid clusters

Directory of Open Access Journals (Sweden)

J. Lengyel

2017-11-01

Full Text Available We investigate the mixed sulfuric acid–water clusters in a molecular beam experiment with electron attachment and negative ion mass spectrometry and complement the experiment by density functional theory (DFT calculations. The microhydration of (H2SO4m(H2On clusters is controlled by the expansion conditions, and the electron attachment yields the main cluster ion series (H2SO4m(H2OnHSO4− and (H2OnH2SO4−. The mass spectra provide an experimental evidence for the onset of the ionic dissociation of sulfuric acid and ion-pair (HSO4−  ⋅  ⋅  ⋅  H3O+ formation in the neutral H2SO4(H2On clusters with n ≥ 5 water molecules, in excellent agreement with the theoretical predictions. In the clusters with two sulfuric acid molecules (H2SO42(H2On this process starts as early as n ≥ 2 water molecules. The (H2SO4m(H2OnHSO4− clusters are formed after the dissociative electron attachment to the clusters containing the (HSO4−  ⋅  ⋅  ⋅  H3O+ ion-pair structure, which leads to the electron recombination with the H3O+ moiety generating H2O molecule and the H-atom dissociation from the cluster. The (H2OnH2SO4− cluster ions point to an efficient caging of the H atom by the surrounding water molecules. The electron-energy dependencies exhibit an efficient electron attachment at low electron energies below 3 eV, and no resonances above this energy, for all the measured mass peaks. This shows that in the atmospheric chemistry only the low-energy electrons can be efficiently captured by the sulfuric acid–water clusters and converted into the negative ions. Possible atmospheric consequences of the acidic dissociation in the clusters and the electron attachment to the sulfuric acid–water aerosols are discussed.

Resonant inelastic collisions of electrons with diatomic molecules

International Nuclear Information System (INIS)

Houfek, Karel

2012-01-01

In this contribution we give a review of applications of the nonlocal resonance theory which has been successfully used for treating the nuclear dynamics of low-energy electron collisions with diatomic molecules over several decades. We give examples and brief explanations of various structures observed in the cross sections of vibrational excitation and dissociative electron attachment to diatomic molecules such as threshold peaks, boomerang oscillations below the dissociative attachment threshold, or outer-well resonances.

Resonant inelastic collisions of electrons with diatomic molecules

Energy Technology Data Exchange (ETDEWEB)

Houfek, Karel, E-mail: karel.houfek@gmail.com [Institute of Theoretical Physics, Faculty of Mathematics and Physics, Charles University, V Holesovickach 2, 180 00 Prague 8 (Czech Republic)

2012-05-15

In this contribution we give a review of applications of the nonlocal resonance theory which has been successfully used for treating the nuclear dynamics of low-energy electron collisions with diatomic molecules over several decades. We give examples and brief explanations of various structures observed in the cross sections of vibrational excitation and dissociative electron attachment to diatomic molecules such as threshold peaks, boomerang oscillations below the dissociative attachment threshold, or outer-well resonances.

Attachment and psychosis

NARCIS (Netherlands)

Korver, N.

2014-01-01

The main goal of this thesis was to further our understanding of current psychosocial models by introducing attachment as a relevant developmental framework. Firstly, attachment theory provides a psychosocial model for a developmental pathway to psychosis. Secondly, after expression of psychotic

Hydration dynamics in water clusters via quantum molecular dynamics simulations

Energy Technology Data Exchange (ETDEWEB)

Turi, László, E-mail: turi@chem.elte.hu [Department of Physical Chemistry, Eötvös Loránd University, Budapest 112, P. O. Box 32, H-1518 (Hungary)

2014-05-28

We have investigated the hydration dynamics in size selected water clusters with n = 66, 104, 200, 500, and 1000 water molecules using molecular dynamics simulations. To study the most fundamental aspects of relaxation phenomena in clusters, we choose one of the simplest, still realistic, quantum mechanically treated test solute, an excess electron. The project focuses on the time evolution of the clusters following two processes, electron attachment to neutral equilibrated water clusters and electron detachment from an equilibrated water cluster anion. The relaxation dynamics is significantly different in the two processes, most notably restoring the equilibrium final state is less effective after electron attachment. Nevertheless, in both scenarios only minor cluster size dependence is observed. Significantly different relaxation patterns characterize electron detachment for interior and surface state clusters, interior state clusters relaxing significantly faster. This observation may indicate a potential way to distinguish surface state and interior state water cluster anion isomers experimentally. A comparison of equilibrium and non-equilibrium trajectories suggests that linear response theory breaks down for electron attachment at 200 K, but the results converge to reasonable agreement at higher temperatures. Relaxation following electron detachment clearly belongs to the linear regime. Cluster relaxation was also investigated using two different computational models, one preferring cavity type interior states for the excess electron in bulk water, while the other simulating non-cavity structure. While the cavity model predicts appearance of several different hydrated electron isomers in agreement with experiment, the non-cavity model locates only cluster anions with interior excess electron distribution. The present simulations show that surface isomers computed with the cavity predicting potential show similar dynamical behavior to the interior clusters of

Threshold electron impact ionization of molecules (CF4, CHF3, CH4, C3H8) and clusters (Ar, Ne, H2, D2), dissociative electron attachment to hydrogen and surface induced reactions of fullerenes (Cn, n=50-60)

International Nuclear Information System (INIS)

Fiegele, T.

2001-02-01

After many years of research the accurate determination and interpretation of threshold energies at which a molecule is ionized by electron impact remains still difficult. The reasons for this are a number of technical obstacles like preparing electrons with a high energy resolution and a complicated physical situation in the reaction complex involving a quantum mechanical many body system. The use of photoionization sometimes appears to be less difficult but nevertheless the values obtained by this technique are not directly comparable to those obtained by electron impact studies. With the use of a newly constructed hemispherical electron monochromator the interaction of electrons under high energy resolution (up to 30 meV) with atoms, molecules and clusters was investigated. In the present study two new techniques have been invoked to obtain more information about the energy resolution of the electrons. Up to now it was only possible to determine the electron energy resolution with the help of s-wave attachment cross sections, e.g. the Cl-/CCl4 resonance at 0 eV. The new techniques allow the investigation at higher energies (at about 12 up to about 58 eV) and by using positive ions. Especially in the case of measuring threshold energies of positive ions the new methods have the advantage that there is no need to change between positive and negative ions. Additionally one gets information about the calibration and the linearity of the energy scale. The value at which the resolution is determined lies also in the range of the threshold. The results show that the resolution is constant over a large electron energy range. Due to low ion signals at the threshold regions the used electron energy resolution was set at about 120 meV for most of the present measurements. In the present work it was for the first time possible to measure accurately the appearance energies for rare gas cluster ions (Ar, Ne) and for hydrogen cluster ions. There are two important observations

The optical/ultraviolet excess of isolated neutron stars in the resonant cyclotron scattering model

Science.gov (United States)

Tong, Hao; Xu, Ren-Xin; Song, Li-Ming

2011-12-01

X-ray dim isolated neutron stars are peculiar pulsar-like objects, characterized by their Planck-like spectrum. In studying their spectral energy distributions, optical/ultraviolet (UV) excess is a long standing problem. Recently Kaplan et al. measured the optical/UV excess for all seven sources, which is understandable in the resonant cyclotron scattering (RCS) model previously addressed. The RCS model calculations show that the RCS process can account for the observed optical/UV excess for most sources. The flat spectrum of RX J2143.0+0654 may be due to contributions from the bremsstrahlung emission of the electron system in addition to the RCS process.

Anaemia and skin pigmentation after excessive cupping therapy by an unqualified therapist in Korea: a case report.

Science.gov (United States)

Kim, Kun Hyung; Kim, Tae-Hun; Hwangbo, Min; Yang, Gi Young

2012-09-01

A case is reported of skin pigmentation and associated anemia resulting from persistently repeated cupping therapies performed by an unqualified practitioner in South Korea. Almost 30 sessions of excessive cupping therapies with blood loss over two months yielded little benefit but led the patient to admit a hospital and receive blood transfusion for acquired iron deficiency anemia. Skin pigmentation on the cupping-attached region remained without any subjective discomfort. We suggest the importance of qualified health professionals when receiving cupping treatments.

Effect of Attachment-Based Therapy on Behavioral Disorders in Girls with Attachment Problems

Directory of Open Access Journals (Sweden)

Marzieh Jahanbakhsh

2014-09-01

Full Text Available Background: Multidimensional and complex nature of children`s behavioral disorders requires assessment and usage of modern treatments. The present study investigated the effects of attachment-based therapy on behavioral disorders (depression, over anxiety and oppositional defiant in girl students of primary school who had attachment problems. Materials and Methods: This study is an empirical plan with pretest-posttest and control group. The target samples were 34 individuals of 388 second and fourth grade students of primary school that had highest scores on attachment problems and behavioral disorders (depression, over anxiety and oppositional defiant. Evaluation implemented using Randolph attachment disorder questionnaire (RADQ and Ontario mental health test. Mothers were presented in 10 group sessions of attachment-based intervention and its effects investigated in their girl`s behavioral disorders (depression, over anxiety and oppositional defiant. Results: Reduction rate of behavioral disorders general scores (depression, over anxiety and oppositional defiant of experimental group compared with control group showed significant decreases in posttest and three months follow up. Conclusion: The attachment based therapy offered for mothers of the girls with attachment problems was effective to reduction of behavioral disorders (depression, over anxiety and oppositional defiant symptoms in their children and the mother`s continues attention to interventional methods showed more improvement in follow up evaluation.

Ion and electron swarm studies of relevance to plasma processing: positive ion-molecule and electron-molecule studies of SF6 and derivatives

International Nuclear Information System (INIS)

Atterbury, C.; Kennedy, R.A.; Critchley, A.D.J.; Mayhew, C.A.

2002-01-01

Many sequential and parallel chemical reactions involving charged species occur in a plasma. Data needed to model plasma's chemical and physical environment includes cross-section, rate coefficients, and product ion distribution of electron-molecule and ion-molecule processes. Such reactions are studied by our group away from the complexity of the plasma environment, with experimental techniques that allow us to concentrate on a single process, where usually only one or two species are involved. A molecule commonly used in plasma etching applications is SF 6 1,2 . We have performed a series of positive ion-molecule and electron attachment studies on SF 6 and related molecules, including SeF 6 , TeF 6 (i.e. XF 6 molecules), SF 5 CF 3 and SF 5 Cl (i.e. SF 5 X molecules) 3- (. The studies of ion reactions with and electron attachment to SF 6 and physically similar molecules are of value when seeking to understand the ion and electron chemistry occurring in SF 6 containing plasma. The result of these studies are presented in this poster. Ion-molecule reactions. Rate coefficients and ion product branching ratios have been determined with the Selected Ion Flow Tube (SIFT) at room temperature (300 K) for reactions of SF 5 X with the following twenty-two cations; Ne + , F + , Ar + , N 2 + , N + , CO + , CO 2 + , O + , N 2 O + , O 2 + , SF 4 + , CF 2 + , SF + , SF 2 + , NO 2 + , SF 5 + , NO + , CF + , CF 3 + , SF 3 + , and H 3 O + (listed in order of decreasing recombination energy). SF 2 + , NO 2 + , NO + , SF 3 + , and H 3 O + are found to be unreacted with both SF 5 CF 3 and SF 5 Cl. The majority of the other reactions proceed with rate coefficients that are close to the capture value. Those found to occur at rates significantly less than the capture mechanism value re the reactions of O 2 + , SF + , SF 5 + , and CF 3 + with SF 5 CF 3 , and SF 4 + and SF 5 + with SF 5 Cl. Several distinction processes are observed among the large number of reactions studied, including

The effect of recombination and attachment on meteor radar diffusion coefficient profiles

Science.gov (United States)

Lee, C. S.; Younger, J. P.; Reid, I. M.; Kim, Y. H.; Kim, J.-H.

2013-04-01

Estimates of the ambipolar diffusion coefficient producedusing meteor radar echo decay times display an increasing trend below 80-85 km, which is inconsistent with a diffusion-only theory of the evolution of meteor trails. Data from the 33 MHz meteor radar at King Sejong Station, Antarctica, have been compared with observations from the Aura Earth Observing System Microwave Limb Sounder satellite instrument. It has been found that the height at which the diffusion coefficient gradient reverses follows the height of a constant neutral atmospheric density surface. Numerical simulations of meteor trail diffusion including dissociative recombination with atmospheric ions and three-body attachment of free electrons to neutral molecules indicate that three-body attachment is responsible for the distortion of meteor radar diffusion coefficient profiles at heights below 90 km, including the gradient reversal below 80-85 km. Further investigation has revealed that meteor trails with low initial electron line density produce decay times more consistent with a diffusion-only model of meteor trail evolution.

Associations among Adult Attachment Presentations, Maternal Sensitivity, and Infant-Mother Attachment in a Sample of Adolescent Mothers.

Science.gov (United States)

Ward, Mary J.; Carlson, Elizabeth A.

1995-01-01

Associations among adolescent attachment organization, maternal sensitivity, and infant attachment organization were examined prospectively in 72 teenaged mother-infant dyads. Pregnant teenagers' attachment organizations predicted both sensitivity and infant-mother attachments. Associations between maternal sensitivity and infant attachment were…

Performance of Submerged Aerated Biofilters for Wastewater Treatment and Excess Biological Sludge Production

Directory of Open Access Journals (Sweden)

Mohammad A. Baghapour

2007-01-01

Full Text Available Minimizing sludge production in the treatment facility is a reasonable measure to reduce waste in sewage treatment, especially as regards excess biological sludge. In this regard, submerged aerated filters' (SAFs have recently found increasing applications in treatment facilities. Thanks to their treatment mechanism, they have greatly contributed to reduction of waste production and, thereby, to reduced treatment costs. Biomass growths of both attached and suspended types take place in these filters. However, little attention has been paid to suspended sludge production and to its relationship with the physical properties of the filter. The design and application criterion for these filters is the organic loadings on unit of area or unit of volume of the media used in these filters. In this study, four filters with different physical properties and different specific areas were loaded with synthetic wastewater made of low-fat dry milk powder for five different hydraulic retention times to evaluate excess sludge production rates in submerged aerated filters. It was shown that increasing specific area increased SCOD removal efficiency up to a maximum level in saturated growths after which point the removal efficiency remained unchanging or decreased. The results also revealed that decreased hydraulic retention times increased sludge production rates in all the study columns and that media with higher porosity levels produced less excess sludge despite lower pollutant removal efficiency.

Predictors of excessive use of social media and excessive online gaming in Czech teenagers.

Science.gov (United States)

Spilková, Jana; Chomynová, Pavla; Csémy, Ladislav

2017-12-01

Background and aims Young people's involvement in online gaming and the use of social media are increasing rapidly, resulting in a high number of excessive Internet users in recent years. The objective of this paper is to analyze the situation of excessive Internet use among adolescents in the Czech Republic and to reveal determinants of excessive use of social media and excessive online gaming. Methods Data from secondary school students (N = 4,887) were collected within the 2015 European School Survey Project on Alcohol and Other Drugs. Logistic regression models were constructed to describe the individual and familial discriminative factors and the impact of the health risk behavior of (a) excessive users of social media and (b) excessive players of online games. Results The models confirmed important gender-specific distinctions - while girls are more prone to online communication and social media use, online gaming is far more prevalent among boys. The analysis did not indicate an influence of family composition on both the excessive use of social media and on excessive online gaming, and only marginal effects for the type of school attended. We found a connection between the excessive use of social media and binge drinking and an inverse relation between excessive online gaming and daily smoking. Discussion and conclusion The non-existence of significant associations between family environment and excessive Internet use confirmed the general, widespread of this phenomenon across the social and economic strata of the teenage population, indicating a need for further studies on the topic.

Attachment to the Romantic Partner and Sibling: Attachment Hierarchies of Twins and Non-Twin Siblings

Directory of Open Access Journals (Sweden)

Sascha Schwarz

2015-12-01

Full Text Available Previous studies have shown that romantic partners and siblings are important attachment figures. This study compares the attachment to the romantic partner with the attachment to the sibling as a function of the participant’s sibling type among monozygotic (MZ twins, dizygotic (DZ twins, and non-twin (NT siblings. The results show that MZ twins prefer their sibling to their romantic partner whereas DZ twins are equally attached to their sibling and romantic partner. In contrast, NT siblings are more attached to their romantic partner compared to their sibling. These results indicate that genetic relatedness has profound impact on a person’s attachment hierarchy and the relative rank of the romantic partner and the sibling.

Childhood Attachment to Pets: Associations between Pet Attachment, Attitudes to Animals, Compassion, and Humane Behaviour

Directory of Open Access Journals (Sweden)

Roxanne D. Hawkins

2017-05-01

Full Text Available Attachment to pets has an important role in children’s social, emotional, and cognitive development, mental health, well-being, and quality of life. This study examined associations between childhood attachment to pets and caring and friendship behaviour, compassion, and attitudes towards animals. This study also examined socio-demographic differences, particularly pet ownership and pet type. A self-report survey of over one thousand 7 to 12 year-olds in Scotland, UK, revealed that the majority of children are strongly attached to their pets, but attachment scores differ depending on pet type and child gender. Analysis revealed that attachment to pets is facilitated by compassion and caring and pet-directed friendship behaviours and that attachment to pets significantly predicts positive attitudes towards animals. The findings have implications for the promotion of prosocial and humane behaviour. Encouraging children to participate in pet care behaviour may promote attachment between children and their pet, which in turn may have a range of positive outcomes for both children (such as reduced aggression, better well-being, and quality of life and pets (such as humane treatment. This study enhances our understanding of childhood pet attachment and has implications for humane education and promoting secure emotional attachments in childhood.

Concordance of attachment representations in preschool siblings assessed by the attachment story completion task

OpenAIRE

Werner, Helene; Zahn, Salome; Titze, Karl; Walitza, Susanne; Zulauf Logoz, Marina

2015-01-01

Several studies have indicated only a modest concordance of attachment security in siblings in infancy. Until now, very little was known about the concordance of siblings’ attachment security beyond infancy, as assessed by the attachment story completion task. This cross-sectional study aims to examine the concordance of attachment representations of 38 first-born (4–7 years) and 38 second-born (3–5 years) siblings living in middle-class two-parent families. Personality factors and the level ...

[The interpretation of attachment in the Szondi test and in the questionnaire processes of attachment theory].

Science.gov (United States)

Török I, András; Vincze, Gábor

2011-01-01

[corrected] The Szondi-test is widely applied in clinical diagnostics in Hungary too, and the evidence resulting from the theory is that we can get information about attachment during its interpreting. Its validity is proven by empirical research and clinical experiences. By analyzing the modern attachment theory more thoroughly, it becomes clear in what ways the Szondi-test constellations regarding attachment are different from the classificationbased on questionnaires, allowing the discrete measurement of the attachment style. With the Szondi-test the classification to attachment style is more insecure, but if it is completed with exploration, it is more informative in vector C (vector of relation, attachment information), while short questionnaires make the classification to attachment style possible. In our empirical analysis we represent the integration of the above mentioned clinical and theoretical experiences. In the present analysis we compare the vector C and S constellation of the two-profile Szondi-test of 80 persons with the dimensions of ECR-R questionnaire and with Collins and Read's questionnaire classification regarding attachment style. The statistical results refer to the fact that there is a legitimacy to compare questionnaire processes allowing the discrete classification of attachment and the Szondi-test's information content regarding attachment. With applying the methods together, we get a unique, complementary section of the information relating to attachment. Comparing the two methods (projective and questionnaire) establishes the need of theoretical integration as well. We also make an attempt to explain Fraley's evolutionary non-adaptivity of avoidant attachment, in the case of whose presence adaptivity of early attachment, counterbalancing the exploration and security need, and providing closeness--farness loses its balance.

Lead-Free Electronics: Impact for Space Electronics

Science.gov (United States)

Sampson, Michael J.

2010-01-01

Pb is used as a constituent in solder alloys used to connect and attach electronic parts to printed wiring boards (PWBs). Similar Pbbearing alloys are electroplated or hot dipped onto the terminations of electronic parts to protect the terminations and make them solderable. Changing to Pb-free solders and termination finishes has introduced significant technical challenges into the supply chain. Tin/lead (Sn/Pb) alloys have been the solders of choice for electronics for more than 50 years. Pb-free solder alloys are available but there is not a plug-in replacement for 60/40 or 63/37 (Sn/Pb) alloys, which have been the industry workhorses.

Studies of some elementary processes involving electrons in the gas phase by pulse-radiolysis microwave-cavity technique

International Nuclear Information System (INIS)

Sunagawa, Takeyoshi; Makita, Takeshi; Musasa, Hirofumi; Tatsumi, Yoshitsugu; Shimamori, Hiroshi

1995-01-01

The pulse radiolysis-microwave cavity technique has been employed for detection of free electrons in the gas phase. Presented are results of the observation of electron disappearance by attachment to molecules, the electron thermalization (energy loss) processes in the presence of an electron-attaching compound, and the formation of electrons by Penning ionization. (author)

Tuning the wettability of calcite cubes by varying the sizes of the polystyrene nanoparticles attached to their surfaces

International Nuclear Information System (INIS)

He Yongjun; Li Tanliang; Yu Xiangyang; Zhao Shiyong; Lu Jianhua; He Jia

2007-01-01

The wettability of calcite cubes was tuned by varying the sizes of the polystyrene nanoparticles attached to their surfaces via a dispersion polymerization. The products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersion spectrum (EDS) and Fourier transformation infrared spectrum (FTIR). The results showed that the hydrophobicity of the calcite cubes was enhanced with the increase of the size of the polystyrene nanoparticles attached. Using polystyrene nanoparticle-attached calcite cubes (PNACC) as emulsifiers, stable water-in-tricaprylin Pickering emulsions were produced. By gelling the water droplets of the Pickering emulsions, the hierarchical structures of polystyrene nanoparticle-attached calcite cube-armored microspheres were obtained. The polystyrene nanoparticle-attached calcite cubes were expected to have novel surface properties similar neither to traditional Pickering particles, nor to macroscopically asymmetrical Janus particles

Attachment theory: progress and future directions.

Science.gov (United States)

Fearon, R M Pasco; Roisman, Glenn I

2017-06-01

Attachment is a key subfield in the area of parenting and parent-child relationships research. In this brief overview, we summarise what we consider to be the state-of-the-art of attachment research, focusing primarily on the nature and significance of attachment in infancy and early childhood. We review 4 major topics that are central issues in the scientific literature on attachment: (1) the role of the environment in the development of attachment, (2) the intergenerational transmission of patterns of attachment, (3) the stability of attachment patterns through early adulthood, and (4) the role of attachment in adjustment and maladjustment. We conclude by highlighting several critical unresolved issues and priorities for future research. Copyright © 2017. Published by Elsevier Ltd.

Conventional physics can explain cold fusion excess heat

Science.gov (United States)

Chubb, S. R.

In 1989, when Fleischmann, Pons and Hawkins (FP), claimed they had created room temperature, nuclear fusion in a solid, a firestorm of controversy erupted. Beginning in 1991, the Office of Naval Research began a decade-long study of the FP excess heat effect. This effort documented the fact that the excess heat that FP observed is the result of a form of nuclear fusion that can occur in solids at reduced temperature, dynamically, through a deuteron (d)+d□4He reaction, without high-energy particles or □ rays. A key reason this fact has not been accepted is the lack of a cogent argument, based on fundamental physical ideas, justifying it. In the paper, this question is re-examined, based on a generalization of conventional energy band theory that applies to finite, periodic solids, in which d's are allowed to occupy wave-like, ion band states, similar to the kinds of states that electrons occupy in ordinary metals. Prior to being experimentally observed, the Ion Band State Theory (IBST) of cold fusion predicted a potential d+d□4He reaction, without high energy particles, would explain the excess heat, the 4He would be found in an unexpected place (outside heat-producing electrodes), and high-loading, x□1, in PdDx, would be required.

Attachment icebergs: Maternal and child health nurses' evaluation of infant-caregiver attachment.

Science.gov (United States)

Bryant, Edith; Ridgway, Lael; Lucas, Sandra

2016-05-01

Secure attachment of infants to their caregiver is important when promoting the emotional wellbeing and mental health of infants. Maternal and child health (MCH) nurses are well positioned to observe the quality of interactions between infants and caregivers and to assess and intervene. However, as yet there are no approved methods to assess the emotional and mental health of infants in community settings. A qualitative descriptive study of 12 MCH nurses in Victoria, Australia, using semi-structured interviews, was thematically analysed. The data revealed that nurses used many skills to identify and manage attachment difficulties. Key among these were observations of interactions, collaboration with caregivers and reflective practice. Assessments and interventions are also influenced by nurses' emotions, attitudes and workplace factors. An unexpected finding was that attachment markers can be likened to an 'iceberg': warning indicators at the tip can be easily observed by the nurse, while the less obvious underlying factors need to be explored in order to support attachment and improve infant mental health outcomes. Education for nurses should include concepts of attachment and link behaviours with emotional wellbeing.

Attachment Patterns in the Psychotherapy Relationship: Development of the Client Attachment to Therapist Scale.

Science.gov (United States)

Mallinckrodt, Brent; And Others

1995-01-01

Describes development of an instrument, the Client Attachment to Therapist Scale (CATS). CATS factors correlated in expected directions with survey measures of object relations, client-rated working alliance, social self-efficacy, and adult attachment. Cluster analysis revealed four types of client attachment. Discusses implications of attachment…

Attachment at (not to) work: applying attachment theory to explain individual behavior in organizations.

Science.gov (United States)

Richards, David A; Schat, Aaron C H

2011-01-01

In this article, we report the results of 2 studies that were conducted to investigate whether adult attachment theory explains employee behavior at work. In the first study, we examined the structure of a measure of adult attachment and its relations with measures of trait affectivity and the Big Five. In the second study, we examined the relations between dimensions of attachment and emotion regulation behaviors, turnover intentions, and supervisory reports of counterproductive work behavior and organizational citizenship behavior. Results showed that anxiety and avoidance represent 2 higher order dimensions of attachment that predicted these criteria (except for counterproductive work behavior) after controlling for individual difference variables and organizational commitment. The implications of these results for the study of attachment at work are discussed.

Adult Attachment Style and Suicidality.

Science.gov (United States)

Miniati, Mario; Callari, Antonio; Pini, Stefano

2017-09-01

There is evidence in the literature that adverse early attachment experiences and subsequent attachment insecurities during adulthood would lead to pessimism, low self-esteem, hopelessness and, ultimately, to suicide risk. This paper aims to review finding on the link between attachment style and suicidality. We searched the literature using the database of the U.S. National Center for Biotechnology Information (NCBI)-MedLine/Pubmed system from January 1992 until December 2016. We started with 1992 because, as far as we know, there are no published studies exploring the relationship between suicide and insecure attachment before that year. We considered reports published on the relationship between attachment style and suicidality. We applied several combinations of the following search terms: attachment, adult attachment style and suicidality, suicide, suicidal ideation, suicidal behavior or suicidal thoughts, and suicide attempts. We selected only English language studies. Research suggests that insecure attachment style, mostly anxious, and unresolved traumas are associated with an increased suicide risk. Few studies prospectively examined clinical course, comorbid psychiatric disorders, familial suicidality or other psychosocial factors. Further research is needed to highlight the nature of the link between attachment and suicidality. The presence of suicidal ideation and attempts might be a consequence of an underlying interaction between the emergence of psychiatrics symptoms, and the long-lasting presence of inadequate patterns of attachment. Within this context, Separation Anxiety Disorder, categorized in the DSM-5 as a condition not confined to childhood but as an anxiety disorder that may occur through the entire lifespan, might be the a key for the comprehension of this link. From a neurobiological point of view, the role of oxytocin remains unclear.

Attachment behavior and mother-child conversations as predictors of attachment representations in middle childhood: a longitudinal study.

Science.gov (United States)

Dubois-Comtois, Karine; Cyr, Chantal; Moss, Ellen

2011-07-01

This study examines longitudinal links between mother-child conversations and attachment patterns in early childhood and later attachment representations. It also tests the role of conversations as mediators in the association between behavioral security and attachment representations. Mother-child conversations (snack-time) and attachment behaviors (Separation-Reunion procedure) were assessed for 83 5.5-year-olds while attachment representations (attachment narratives) were measured at 8.5 years of age. Results showed correspondence between attachment behaviors and representations for secure-confident, ambivalent-preoccupied, and disorganized/controlling-frightened groups. Affective quality of mother-child conversations predicted both child attachment behaviors and representations. Secure and confident children showed greater integration of affective information, ambivalent and preoccupied children more affect exaggeration, and disorganized/controlling and frightened children more chaotic conversations. Avoidant children tended to show more affect minimization in conversations. Finally, mother-child conversations centered on the sharing of emotions and thoughts mediated the relation between behavioral and representational attachment security, which underscores the importance of mother-child conversations in the development of attachment representations in childhood.

Silver Nanocube and Nanobar Growth via Anisotropic Monomer Addition and Particle Attachment Processes

Energy Technology Data Exchange (ETDEWEB)

Xiao, Dongdong [Physical; Wu, Zhigang [School; Song, Miao [Physical; Chun, Jaehun [Physical; Schenter, Gregory K. [Physical; Li, Dongsheng [Physical

2018-01-11

Understanding the growth mechanism of noble metal nanocrystals during solution synthesis is of significant importance for shape and property control. However, much remains unknown about the growth pathways of metal nanoparticles due to lack of direct observation. Using an in-situ transmission electron microscopy technique, we directly observed Ag nanocube and nanobar growth in aqueous solution through both classical monomer-by-monomer addition and non-classical particle attachment processes. During the particle attachment process, Ag nanocubes and nanobars formed via both oriented and non-oriented attachment. Our calculations, along with dynamics of the observed attachment, showed that van der Waals force overcame hydrodynamic and friction forces and drove the particles toward each other. During classical growth, an anisotropic growth was also revealed, and the resulting unsymmetrical shape constituted an intermediate state for Ag nanocube growth. We hypothesized that the temporary symmetry breaking resulted from different growth rates on {001} surfaces due to a local surface concentration variation caused by the imbalance between the consumption of Ag+ near the surface and the diffusion of Ag+ from bulk to surface.

ACTIVATION PARAMETERS AND EXCESS THERMODYANAMIC ...

African Journals Online (AJOL)

Applying these data, viscosity-B-coefficients, activation parameters (Δμ10≠) and (Δμ20≠) and excess thermodynamic functions, viz., excess molar volume (VE), excess viscosity, ηE and excess molar free energy of activation of flow, (GE) were calculated. The value of interaction parameter, d, of Grunberg and Nissan ...

The Adult Attachment Projective Picture System: integrating attachment into clinical assessment.

Science.gov (United States)

George, Carol; West, Malcolm

2011-01-01

This article summarizes the development and validation of the Adult Attachment Projective System (AAP), a measure we developed from the Bowlby-Ainsworth developmental tradition to assess adult attachment status. The AAP has demonstrated excellent concurrent validity with the Adult Attachment Interview (George, Kaplan, & Main, 1984/1985/1996; Main & Goldwyn, 1985-1994; Main, Goldwyn, & Hesse, 2003), interjudge reliability, and test-retest reliability, with no effects of verbal intelligence or social desirability. The AAP coding and classification system and application in clinical and community samples are summarized. Finally, we introduce the 3 other articles that are part of this Special Section and discuss the use of the AAP in therapeutic assessment and treatment.

Father attachment, father emotion expression, and children's attachment to fathers: The role of marital conflict.

Science.gov (United States)

Bi, Shuang; Haak, Eric A; Gilbert, Lauren R; El-Sheikh, Mona; Keller, Peggy S

2018-06-01

The current study examined relations between father attachment to spouses and child attachment to fathers in middle childhood, focusing on father emotion expressions in father-child interactions as mediators and marital conflict as a moderator of relations. Participants were 199 children between 6 and 12 years of age and their fathers. Fathers completed questionnaires about their attachment to their spouses, and both fathers and mothers reported on their marital conflict. Fathers also discussed a difficult topic with their children for 5 min, and fathers' positive and negative emotion expression during the discussions were coded. Children completed questionnaires through an interview about their attachment to their father. Father insecure attachment interacted with marital conflict in predicting more negative emotions and less positive emotions during father-child interactions. Specifically, in the context of higher marital conflict in this community sample, fathers who reported greater preoccupied attachment to their spouses exhibited more negative emotions and less positive emotions when interacting with their children. In turn, more father negative emotions and less positive emotions were associated with children's less secure attachment to fathers. In contrast, father fearful attachment interacted with marital conflict to predict less negative emotion and more positive emotion during interactions with children. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Attachment within life history theory: an evolutionary perspective on individual differences in attachment.

Science.gov (United States)

Szepsenwol, Ohad; Simpson, Jeffry A

2018-03-15

In this article, we discuss theory and research on how individual differences in adult attachment mediate the adaptive calibration of reproductive strategies, cognitive schemas, and emotional expression and regulation. We first present an integration of attachment theory and life history theory. Then, we discuss how early harsh and/or unpredictable environments may promote insecure attachment by hampering parents' ability to provide sensitive and reliable care to their children. Finally, we discuss how, in the context of harsh and/or unpredictable environments, different types of insecure attachment (i.e. anxiety and avoidance) may promote evolutionary adaptive reproductive strategies, cognitive schemas, and emotional expression and regulation profiles. Copyright © 2018 Elsevier Ltd. All rights reserved.

Activating Attachments Reduces Memories of Traumatic Images.

Directory of Open Access Journals (Sweden)

Richard A Bryant

Full Text Available Emotional memories, and especially intrusive memories, are a common feature of many psychological disorders, and are overconsolidated by stress. Attachment theory posits that activation of mental representations of attachment figures can reduce stress and boost coping. This study tested the proposition that attachment activation would reduce consolidation of emotional and intrusive memories. Sixty-seven undergraduate students viewed subliminal presentations of traumatic and neutral images, which were preceded by subliminal presentations of either attachment-related images or non-attachment-related images; free recall and intrusive memories were assessed two days later. Participants with low avoidant attachment tendencies who received the attachment primes recalled fewer memories and reported fewer intrusions than those who received the non-attachment primes. Unexpectedly, those with high anxious attachment tendencies reported fewer memories. These findings generally accord with attachment theory, and suggest that consolidation of emotional memories can be moderated by activation of attachment representations.

Microbial community variation and functions to excess sludge reduction in a novel gravel contact oxidation reactor

Energy Technology Data Exchange (ETDEWEB)

Lin Shanshan; Jin, Y.; Fu, L. [School of Urban and Environmental Science, Northeast Normal University, Changchun (China); Quan, C. [Jilin University, College of medicine, Changchun (China); Yang, Y.S., E-mail: yangy6@cf.ac.uk [Cardiff University, School of Earth and Ocean Sciences, Cardiff CF10 3YE (United Kingdom)

2009-06-15

both in GCOR (15 no. per 20 ml) and in ASR (15 no. per 20 ml); the next abundant group was attachment plants 10 no. per 20 ml in GCOR and 4 no. per 20 ml in ASR, respectively. Rotifers and copepoda belonging to metazoan were only present in GCOR (8 no. per 20 ml for both rotifers and copepoda). The microbial diversity and population difference both in the GCOR carriers and ASR sludge indicated that the diverse microbes, a large amount of biomass forming longer microbial food chains attached on the carriers may be the main functions for the excess sludge reduction in GCOR.

Microbial community variation and functions to excess sludge reduction in a novel gravel contact oxidation reactor

International Nuclear Information System (INIS)

Lin Shanshan; Jin, Y.; Fu, L.; Quan, C.; Yang, Y.S.

2009-01-01

no. per 20 ml); the next abundant group was attachment plants 10 no. per 20 ml in GCOR and 4 no. per 20 ml in ASR, respectively. Rotifers and copepoda belonging to metazoan were only present in GCOR (8 no. per 20 ml for both rotifers and copepoda). The microbial diversity and population difference both in the GCOR carriers and ASR sludge indicated that the diverse microbes, a large amount of biomass forming longer microbial food chains attached on the carriers may be the main functions for the excess sludge reduction in GCOR.

Effects of Emotion Regulation Training on Attachment Style of Primiparous Pregnant Women with Insecure Attachment

Directory of Open Access Journals (Sweden)

Tayebeh Reyhani

2016-04-01

Full Text Available Background: Pregnant women with insecure attachment style are at high risk of psychiatric disorders. Since emotions are the first coordinators of attachment behavior, emotion regulation training can alter maternal attachment style. In this study, we aimed to evaluate the effects of emotion regulation training on the attachment styles of primiparous pregnant women with insecure attachment style. Aim: This study aimed to evaluate the effects of training programs on the headache of patients after spinal anesthesia. Method: This randomized, clinical trial on 40 primiparous pregnant women with age range of 30-34 years, who were referred to healthcare centers of Mashhad, Iran, during 2014. The data collection instrument was Revised Adult Attachment Scale (RAAS. The participants were assigned to intervention and control groups. A training program was implemented on emotion regulation based on dialectical behavior therapy (DBT for the intervention group. After delivery, RAAS was completed by the mothers again. The control group only received the routine care. To analyze the data, Chi-square and independent t-test were run using SPSS, version 15. Results: Mean ages of the mothers in the intervention and control groups were 26.9±4.04 and 27.5±3.5 years, respectively. According to the results of independent t-test, the difference between the groups was non-significant (P=0.77. The groups were analogous in terms of attachment style pre-intervention. After the intervention, independent t-test did not reflect any significant differences between the groups regarding avoidant (P=0.37 and anxious (P=0.11 attachment styles. However, mean score for secure attachment style was significantly enhanced (P=0.01. Implications for Practice: Our findings revealed that implementation of emotion regulation training increased secure attachment scores. Thus, implementing emotion regulation training program is recommended as part of a program for pre-natal care in healthcare

Relaxation dynamics following transition of solvated electrons

International Nuclear Information System (INIS)

Barnett, R.B.; Landman, U.; Nitzan, A.

1989-01-01

Relaxation dynamics following an electronic transition of an excess solvated electron in clusters and in bulk water is studied using an adiabatic simulation method. In this method the solvent evolves classically and the electron is constrained to a specified state. The coupling between the solvent and the excess electron is evaluated via the quantum expectation value of the electron--water molecule interaction potential. The relaxation following excitation (or deexcitation) is characterized by two time scales: (i) a very fast (/similar to/20--30 fs) one associated with molecular rotations in the first solvation shell about the electron, and (ii) a slower stage (/similar to/200 fs), which is of the order of the longitudinal dielectric relaxation time. The fast relaxation stage exhibits an isotope effect. The spectroscopical consequences of the relaxation dynamics are discussed

Interferences in place attachment: implications for wilderness

Science.gov (United States)

Erin K. Sharpe; Alan W. Ewert

2000-01-01

Previous research on place attachment has tended to focus on attachment formation, with relatively little attention given to factors that disrupt or interfere with formed place attachments. Interferences to attachments are a worthy research area for two reasons: 1) The factors of place attachment are often more salient when being disrupted, and 2) place attachment...

Using attachment theory in mentoring.

Science.gov (United States)

Miles, Kerri

Attachment theory is a useful way to understand the bond between children and the people with whom they have emotional ties--usually caregivers. The theory can also help us to understand any adult relationship that provides closeness and a sense of attachment, especially in times of stress or need. Understanding the nature, cause and effect of the role and function of attachment from a training and development perspective, and different styles of attachment, may improve the quality of the mentoring experience for both mentors and mentees.

Attachment and Dyadic Regulation Processes.

Science.gov (United States)

Overall, Nickola C; Simpson, Jeffry A

2015-02-01

Insecurely attached people have relatively unhappy and unstable romantic relationships, but the quality of their relationships depends on how their partners regulate them. Some partners find ways to regulate the emotional and behavioral reactions of insecurely attached individuals, which promotes greater relationship satisfaction and security. We discuss attachment theory and interdependence dilemmas, and then explain how and why certain responses by partners assuage the cardinal concerns of insecure individuals in key interdependent situations. We then review recent studies illustrating how partners can successfully regulate the reactions of anxiously and avoidantly attached individuals, yielding more constructive interactions. We finish by considering how these regulation processes can create a more secure dyadic environment, which helps to improve relationships and attachment security across time.

Attachment Theory: Progress and Future Directions

OpenAIRE

Fearon, R. M. P.; Roisman, G. I.

2017-01-01

Attachment is a key subfield in the area of parenting and parent-child relationships research. In this brief overview, we summarise what we consider to be the state-of-the-art of attachment research, focusing primarily on the nature and significance of attachment in infancy and early childhood. We review 4 major topics that are central issues in the scientific literature on attachment: (1) the role of the environment in the development of attachment, (2) the intergenerational transmission of ...

Electronic Conduction through Atomic Chains, Quantum Well and Quantum Wire

International Nuclear Information System (INIS)

Sharma, A. C.

2011-01-01

Charge transport is dynamically and strongly linked with atomic structure, in nanostructures. We report our ab-initio calculations on electronic transport through atomic chains and the model calculations on electron-electron and electron-phonon scattering rates in presence of random impurity potential in a quantum well and in a quantum wire. We computed synthesis and ballistic transport through; (a) C and Si based atomic chains attached to metallic electrodes, (b) armchair (AC), zigzag (ZZ), mixed, rotated-AC and rotated-ZZ geometries of small molecules made of 2S, 6C and 4H atoms attaching to metallic electrodes, and (c) carbon atomic chain attached to graphene electrodes. Computed results show that synthesis of various atomic chains are practically possible and their transmission coefficients are nonzero for a wide energy range. The ab-initio calculations on electronic transport have been performed with the use of Landauer-type scattering formalism formulated in terms of Grben's functions in combination with ground-state DFT. The electron-electron and electron-phonon scattering rates have been calculated as function of excitation energy both at zero and finite temperatures for disordered 2D and 1D systems. Our model calculations suggest that electron scattering rates in a disordered system are mainly governed by effective dimensionality of a system, carrier concentration and dynamical screening effects.

Assessing Attachment in Psychotherapy

DEFF Research Database (Denmark)

Talia, Alessandro; Miller-Bottome, Madeleine; Daniel, Sarah I.F.

2017-01-01

The authors present and validate the Patient Attachment Coding System (PACS), a transcript-based instrument that assesses clients' in-session attachment based on any session of psychotherapy, in multiple treatment modalities. One-hundred and sixty clients in different types of psychotherapy...... (cognitive–behavioural, cognitive–behavioural-enhanced, psychodynamic, relational, supportive) and from three different countries were administered the Adult Attachment Interview (AAI) prior to treatment, and one session for each client was rated with the PACS by independent coders. Results indicate strong...... inter-rater reliability, and high convergent validity of the PACS scales and classifications with the AAI. These results present the PACS as a practical alternative to the AAI in psychotherapy research and suggest that clinicians using the PACS can assess clients' attachment status on an ongoing basis...

Excess Entropy and Diffusivity

Indian Academy of Sciences (India)

First page Back Continue Last page Graphics. Excess Entropy and Diffusivity. Excess entropy scaling of diffusivity (Rosenfeld,1977). Analogous relationships also exist for viscosity and thermal conductivity.

24 CFR 236.60 - Excess Income.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Excess Income. 236.60 Section 236... § 236.60 Excess Income. (a) Definition. Excess Income consists of cash collected as rent from the... Rent. The unit-by-unit requirement necessitates that, if a unit has Excess Income, the Excess Income...

Social networking sites in romantic relationships: attachment, uncertainty, and partner surveillance on facebook.

Science.gov (United States)

Fox, Jesse; Warber, Katie M

2014-01-01

Social networking sites serve as both a source of information and a source of tension between romantic partners. Previous studies have investigated the use of Facebook for monitoring former and current romantic partners, but why certain individuals engage in this behavior has not been fully explained. College students (N=328) participated in an online survey that examined two potential explanatory variables for interpersonal electronic surveillance (IES) of romantic partners: attachment style and relational uncertainty. Attachment style predicted both uncertainty and IES, with preoccupieds and fearfuls reporting the highest levels. Uncertainty did not predict IES, however. Future directions for research on romantic relationships and online surveillance are explored.

Improving Light Extraction of Organic Light-Emitting Devices by Attaching Nanostructures with Self-Assembled Photonic Crystal Patterns

Directory of Open Access Journals (Sweden)

Kai-Yu Peng

2014-01-01

Full Text Available A single-monolayered hexagonal self-assembled photonic crystal (PC pattern fabricated onto polyethylene terephthalate (PET films by using simple nanosphere lithography (NSL method has been demonstrated in this research work. The patterned nanostructures acted as a scattering medium to extract the trapped photons from substrate mode of optical-electronic device for improving the overall external quantum efficiency of the organic light-emitting diodes (OLEDs. With an optimum latex concentration, the distribution of self-assembled polystyrene (PS nanosphere patterns on PET films can be easily controlled by adjusting the rotation speed of spin-coater. After attaching the PS nanosphere array brightness enhancement film (BEF sheet as a photonic crystal pattern onto the device, the luminous intensity of OLEDs in the normal viewing direction is 161% higher than the one without any BEF attachment. The electroluminescent (EL spectrum of OLEDs with PS patterned BEF attachment also showed minor color offset and superior color stabilization characteristics, and thus it possessed the potential applications in all kinds of display technology and solid-state optical-electronic devices.

Applications of molecules as high-resolution, high-sensitivity threshold electron detectors

International Nuclear Information System (INIS)

Chutjian, A.

1991-01-01

The goal of the work under the contract entitled ''Applications of Molecules as High-Resolution, High-Sensitivity Threshold Electron Detectors'' (DoE IAA No. DE-AI01-83ER13093 Mod. A006) was to explore the electron attachment properties of a variety of molecules at electron energies not accessible by other experimental techniques. As a result of this work, not only was a large body of basic data measured on attachment cross sections and rate constants; but also extensive theoretical calculations were carried out to verify the underlying phenomenon of s-wave attachment. Important outgrowths of this week were also realized in other areas of research. The basic data have applications in fields such as combustion, soot reduction, rocket-exhaust modification, threshold photoelectron spectroscopy, and trace species detection

Attachment style and adjustment to divorce.

Science.gov (United States)

Yárnoz-Yaben, Sagrario

2010-05-01

Divorce is becoming increasingly widespread in Europe. In this study, I present an analysis of the role played by attachment style (secure, dismissing, preoccupied and fearful, plus the dimensions of anxiety and avoidance) in the adaptation to divorce. Participants comprised divorced parents (N = 40) from a medium-sized city in the Basque Country. The results reveal a lower proportion of people with secure attachment in the sample group of divorcees. Attachment style and dependence (emotional and instrumental) are closely related. I have also found associations between measures that showed a poor adjustment to divorce and the preoccupied and fearful attachment styles. Adjustment is related to a dismissing attachment style and to the avoidance dimension. Multiple regression analysis confirmed that secure attachment and the avoidance dimension predict adjustment to divorce and positive affectivity while preoccupied attachment and the anxiety dimension predicted negative affectivity. Implications for research and interventions with divorcees are discussed.

AMS-02 positron excess and indirect detection of three-body decaying dark matter

Energy Technology Data Exchange (ETDEWEB)

Cheng, Hsin-Chia [Department of Physics, University of California, Davis, CA 95616 (United States); Huang, Wei-Chih [Fakultät für Physik, Technische Universität Dortmund, 44221 Dortmund (Germany); Huang, Xiaoyuan [Physik-Department T30d, Technische Universität München, James-Franck-Straße, D-85748 Garching (Germany); Low, Ian [High Energy Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Tsai, Yue-Lin Sming [Kavli IPMU (WPI), University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Yuan, Qiang, E-mail: cheng@physics.ucdavis.edu, E-mail: wei-chih.huang@tu-dortmund.de, E-mail: huangxiaoyuan@gmail.com, E-mail: ilow@northwestern.edu, E-mail: smingtsai@gmail.com, E-mail: yuanq@pmo.ac.cn [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

2017-03-01

We consider indirect detection of meta-stable dark matter particles decaying into a stable neutral particle and a pair of standard model fermions. Due to the softer energy spectra from the three-body decay, such models could potentially explain the AMS-02 positron excess without being constrained by the Fermi-LAT gamma-ray data and the cosmic ray anti-proton measurements. We scrutinize over different final state fermions, paying special attention to handling of the cosmic ray background and including various contributions from cosmic ray propagation with the help of the LIKEDM package. It is found that primary decays into an electron-positron pair and a stable neutral particle could give rise to the AMS-02 positron excess and, at the same time, stay unscathed against the gamma-ray and anti-proton constraints. Decays to a muon pair or a mixed flavor electron-muon pair may also be viable depending on the propagation models. Decays to all other standard model fermions are severely disfavored.

A study of the efficacy of fathers’ attachment training on paternal-fetal attachment and parental anxiety

Directory of Open Access Journals (Sweden)

Sara Setodeh

2017-12-01

Full Text Available Background . Attachment behaviors play an important role in accepting the identity of the fathers, the pleasant outcome of pregnancy and the child’s growth and development in the future. Objectives . This study aimed to investigate the effect of father’s attachment training (awaiting a child on paternal-fetal attachment and parental anxiety. Material and methods . This clinical trial was conducted on 150 spouses of eligible pregnant women. In the intervention group, four 90-minute training sessions were designed on maternal-fetal attachment, while the control group received routine prenatal care. The questionnaire of paternal-fetal attachment was completed both before and after intervention in both cases and control groups. Data analysis was done in SPSS software using a paired t-test and independent t-test (the significant level was 0.05. Results . The mean score of attachment was reported as 56.61 ± 6.05 and 64.53 ± 6.94 both before and after intervention, respectively. According to the paired t-test, there was a significant difference in the attachment score after intervention (p < 0.001. According to the independent t-test applied a month after intervention, the comparison of fathers’ anxiety scores before and after intervention showed a significant difference between the control and intervention groups (p < 0.001. Conclusions . Training fathers about attachment skills leads to increased paternal-fetal attachment and a lower anxiety score. Therefore, it seems necessary to include education of fathers in prenatal care.

Streptococcus mutans attachment on a cast titanium surface

Directory of Open Access Journals (Sweden)

Sicknan Soares da Rocha

2009-03-01

Full Text Available This study examined by means of scanning electron microscopy (SEM, the attachment of Streptococcus mutans and the corrosion of cast commercially pure titanium, used in dental dentures. The sample discs were cast in commercially pure titanium using the vacuum-pressure machine (Rematitan System. The surfaces of each metal were ground and polished with sandpaper (#300-4000 and alumina paste (0.3 µm. The roughness of the surface (Ra was measured using the Surfcorder rugosimeter SE 1700. Four coupons were inserted separately into Falcon tubes contained Mueller Hinton broth inoculated with S. mutans ATCC 25175 (10(9 cuf and incubated at 37 °C. The culture medium was changed every three days during a 365-day period, after which the falcons were prepared for observations by SEM. The mean Ra value of CP Ti was 0.1527 µm. After S. mutans biofilm removal, pits of corrosion were observed. Despite the low roughness, S. mutans attachment and biofilm formation was observed, which induced a surface corrosion of the cast pure titanium.

Silver Nanocube and Nanobar Growth via Anisotropic Monomer Addition and Particle Attachment Processes.

Science.gov (United States)

Xiao, Dongdong; Wu, Zhigang; Song, Miao; Chun, Jaehun; Schenter, Gregory K; Li, Dongsheng

2018-01-30

Understanding the growth mechanism of noble metal nanocrystals during solution synthesis is of significant importance for shape and property control. However, much remains unknown about the growth pathways of metal nanoparticles due to the lack of direct observation. Using an in situ transmission electron microscopy technique, we directly observed Ag nanocube and nanobar growth in an aqueous solution through both classical monomer-by-monomer addition and nonclassical particle attachment processes. During the particle attachment process, Ag nanocubes and nanobars were formed via both oriented and nonoriented attachment. Our calculations, along with the dynamics of the observed attachment, showed that the van der Waals force overcomes hydrodynamic and friction forces and drives the particles toward each other at separations of 10-100 nm in our experiments. During classical growth, anisotropic growth was also revealed, and the resulting unsymmetrical shape constituted an intermediate state for Ag nanocube growth. We hypothesized that the temporary symmetry breaking resulted from different growth rates on (001) surfaces due to a local surface concentration variation caused by the imbalance between the consumption of Ag + near the surface and the diffusion of Ag + from the bulk to the surface.

Place attachment and natural environmental risk

DEFF Research Database (Denmark)

Bonaiuto, Marino; Alves, Susana; De Dominicis, Stefano

2016-01-01

Little is known about place attachment affecting natural environmental risk perception and coping. A systematic search of social science databases revealed 31 works (1996–2016) directly addressing place attachment in relation to different types of natural hazard risks (e.g., seismic, volcanic, etc.......). Across different contexts, the research shows: (a) positive and/or negative relationships between place attachment and natural environmental risk perception; (b) positive and/or negative relationships between place attachment and risk coping; and (c) mediating and moderating relationships. In particular......, results show that: (a) highly attached individuals perceive natural environmental risks but underestimate their potential effects; (b) highly attached individuals are unwilling to relocate when facing natural environmental risks and more likely to return to risky areas after a natural environmental...

Attachment styles and contingencies of self-worth.

Science.gov (United States)

Park, Lora E; Crocker, Jennifer; Mickelson, Kristin D

2004-10-01

Previous research on attachment theory has focused on mean differences in level of self-esteem among people with different attachment styles. The present study examines the associations between attachment styles and different bases of self-esteem, or contingencies of self-worth, among a sample of 795 college students. Results showed that attachment security was related to basing self-worth on family support. Both the preoccupied attachment style and fearful attachment style were related to basing self-worth on physical attractiveness. The dismissing attachment style was related to basing self-worth less on others' approval, family support, and God's love.

The Effect of Different Water Temperatures on Retention Loss and Material Degradation of Locator Attachments.

Science.gov (United States)

Chiu, Lillian Pui Yuk; Vitale, Nicola Di; Petridis, Haralampos; McDonald, Ailbhe

2017-08-01

To examine the changes in Locator attachments after exposure to different water temperatures and cyclic loading. Four groups of pink Locator attachments (3.0 lb. light retention replacement patrix attachments; 10 per group) were soaked for the equivalent of 5 years of use in distilled water at the following temperatures: 20°C, 37°C, 60°C. One group was kept dry to test the effect of water. A universal testing machine was used to measure the retention force of each treated attachment during 5500 insertion and removal cycles, simulating approximately 5 years of use. The results were compared using Kruskal-Wallis one-way ANOVA by ranks. Surface changes of tested attachments were examined using scanning electron microscopy (SEM). The exposure to 60°C water significantly increased the percentage of retention loss in Locator attachments (p < 0.05) compared to the 20°C water group and significantly reduced the final retention force compared to the other groups (p < 0.05). SEM examinations revealed severe cracking and material degradation in Locator attachments after exposure to 60°C water and cyclic loading, which were not evident in other groups. Cracking was observed after exposure to 60˚C water before cyclic loading. Exposure to 60°C water, potentially similar to denture cleansing procedures, could cause cracking in Locator attachments. Cracking is associated with hydrolytic degradation of nylon at 60°C. The change in structure could result in a significant loss of retention. © 2016 by the American College of Prosthodontists.

Introduction: attachment theory and psychotherapy.

Science.gov (United States)

Levy, Kenneth N

2013-11-01

In this introduction to the JCLP: In Session 69(11) issue on attachment theory and psychotherapy, the key points of attachment theory (Bowlby, , , 1981) and its relevance to psychotherapy are briefly described. The aim of this issue is to provide case illustrations of how an attachment theory perspective and principles can expand our understanding of psychotherapy practice. © 2013 Wiley Periodicals, Inc.

Everything You Want To Know about Attachment.

Science.gov (United States)

Honig, Alice Sterling

This paper discusses infant attachment, which it defines as a long-lasting emotional bond revealed when a child under stress seeks out and tries to stay close to a specific figure. The paper addresses: (1) What is attachment? Who are the pioneers in attachment theory?; (2) How do we notice attachment in action?; (3) Is attachment the only…

Phenotypes of Non-Attached Pseudomonas aeruginosa Aggregates Resemble Surface Attached Biofilm

DEFF Research Database (Denmark)

Alhede, Morten; Kragh, Kasper Nørskov; Qvortrup, Klaus

2011-01-01

For a chronic infection to be established, bacteria must be able to cope with hostile conditions such as low iron levels, oxidative stress, and clearance by the host defense, as well as antibiotic treatment. It is generally accepted that biofilm formation facilitates tolerance to these adverse......, RT-PCR as well as traditional culturing techniques to study the properties of Pseudomonas aeruginosa aggregates. We found that non-attached aggregates from stationary-phase cultures have comparable growth rates to surface attached biofilms. The growth rate estimations indicated that, independently...... were also found to be strikingly similar to flow-cell biofilms. Our data indicate that the tolerance of both biofilms and non-attached aggregates towards antibiotics is reversible by physical disruption. We provide evidence that the antibiotic tolerance is likely to be dependent on both...

Association Between Insecure Attachment and ADHD

DEFF Research Database (Denmark)

Storebø, Ole Jakob; Rasmussen, Pernille Darling; Simonsen, Erik

2016-01-01

OBJECTIVE: Psychological theories have postulated an association between insecure attachment and ADHD. The objective of this study is to investigate possible association between insecure attachment and ADHD in children and adults. METHOD: Review of literature was performed using the Psyc......INFO, Medline, and EMBASE databases. RESULTS: Twenty-nine studies were included in the review. Overall, the studies showed that parental attachment problems and environmental mediating factors were significantly associated with childhood ADHD. Adults with ADHD had a much higher incidence of insecure attachment...... styles than reported in the general population. CONCLUSION: There seems to be a clear association between ADHD and insecure attachment. It is likely that early intervention in the form of parent training and pharmacological treatment may prevent development of attachment problems. But such studies have...

Priming the Secure Attachment Schema Affects the Emotional Face Processing Bias in Attachment Anxiety: An fMRI Research

Directory of Open Access Journals (Sweden)

Xu Chen

2017-04-01

Full Text Available Our study explored how priming with a secure base schema affects the processing of emotional facial stimuli in individuals with attachment anxiety. We enrolled 42 undergraduate students between 18 and 27 years of age, and divided them into two groups: attachment anxiety and attachment secure. All participants were primed under two conditions, the secure priming using references to the partner, and neutral priming using neutral references. We performed repeated attachment security priming combined with a dual-task paradigm and functional magnetic resonance imaging. Participants’ reaction times in terms of responding to the facial stimuli were also measured. Attachment security priming can facilitate an individual’s processing of positive emotional faces; for instance, the presentation of the partner’s name was associated with stronger activities in a wide range of brain regions and faster reaction times for positive facial expressions in the subjects. The current finding of higher activity in the left-hemisphere regions for secure priming rather than neutral priming is consistent with the prediction that attachment security priming triggers the spread of the activation of a positive emotional state. However, the difference in brain activity during processing of both, positive and negative emotional facial stimuli between the two priming conditions appeared in the attachment anxiety group alone. This study indicates that the effect of attachment secure priming on the processing of emotional facial stimuli could be mediated by chronic attachment anxiety. In addition, it highlights the association between higher-order processes of the attachment system (secure attachment schema priming and early-stage information processing system (attention, given the increased attention toward the effects of secure base schema on the processing of emotion- and attachment-related information among the insecure population. Thus, the following study has

Electron attachment and electron ionization of acetic acid clusters embedded in helium nanodroplets

NARCIS (Netherlands)

da Silva, F. Ferreira; Jaksch, S.; Martins, G.; Dang, H. M.; Dampc, M.; Denifl, S.; Maerk, T. D.; Limao-Vieira, P.; Liu, J.; Yang, S.; Ellis, A. M.; Scheier, P.

2009-01-01

The effect of incident electrons on acetic acid clusters is explored for the first time. The acetic acid clusters are formed inside liquid helium nanodroplets and both cationic and anionic products ejected into the gas phase are detected by mass spectrometry. The cation chemistry (induced by

Observational attachment theory-based parenting measures predict children's attachment narratives independently from social learning theory-based measures.

Science.gov (United States)

Matias, Carla; O'Connor, Thomas G; Futh, Annabel; Scott, Stephen

2014-01-01

Conceptually and methodologically distinct models exist for assessing quality of parent-child relationships, but few studies contrast competing models or assess their overlap in predicting developmental outcomes. Using observational methodology, the current study examined the distinctiveness of attachment theory-based and social learning theory-based measures of parenting in predicting two key measures of child adjustment: security of attachment narratives and social acceptance in peer nominations. A total of 113 5-6-year-old children from ethnically diverse families participated. Parent-child relationships were rated using standard paradigms. Measures derived from attachment theory included sensitive responding and mutuality; measures derived from social learning theory included positive attending, directives, and criticism. Child outcomes were independently-rated attachment narrative representations and peer nominations. Results indicated that Attachment theory-based and Social Learning theory-based measures were modestly correlated; nonetheless, parent-child mutuality predicted secure child attachment narratives independently of social learning theory-based measures; in contrast, criticism predicted peer-nominated fighting independently of attachment theory-based measures. In young children, there is some evidence that attachment theory-based measures may be particularly predictive of attachment narratives; however, no single model of measuring parent-child relationships is likely to best predict multiple developmental outcomes. Assessment in research and applied settings may benefit from integration of different theoretical and methodological paradigms.

Next Steps in Attachment Theory.

Science.gov (United States)

Bell, David C

2012-12-01

Thanks to the phenomenal success of attachment theory, great progress has been made in understanding child and adult relationships. The success of attachment theory opens the way to new research directions that can extend its successes even further. In particular, more work on the fundamental nature of attachment that respects recent biological research is important, as is concentrated effort on the related caregiving system.

Next Steps in Attachment Theory

OpenAIRE

Bell, David C.

2012-01-01

Thanks to the phenomenal success of attachment theory, great progress has been made in understanding child and adult relationships. The success of attachment theory opens the way to new research directions that can extend its successes even further. In particular, more work on the fundamental nature of attachment that respects recent biological research is important, as is concentrated effort on the related caregiving system.

Genetic and caregiving-based contributions to infant attachment: unique associations with distress reactivity and attachment security.

Science.gov (United States)

Raby, K Lee; Cicchetti, Dante; Carlson, Elizabeth A; Cutuli, J J; Englund, Michelle M; Egeland, Byron

2012-09-01

In the longitudinal study reported here, we examined genetic and caregiving-based contributions to individual differences in infant attachment classifications. For 154 mother-infant pairs, we rated mothers' responsiveness to their 6-month-old infants during naturalistic interactions and classified infants' attachment organization at 12 and 18 months using the Strange Situation procedure. These infants were later genotyped with respect to the serotonin-transporter-linked polymorphic region (5-HTTLPR). Maternal responsiveness uniquely predicted infants' attachment security. Infants' 5-HTTLPR variation uniquely predicted their subtype of attachment security at 12 months and their subtype of attachment insecurity at 12 and 18 months. The short allele for 5-HTTLPR was associated with attachment classifications characterized by higher emotional distress. These findings suggest that 5-HTTLPR variation contributes to infants' emotional reactivity and that the degree to which caregivers are responsive influences how effectively infants use their caregivers for emotion regulation. Theoretical implications for the study of genetic and caregiving influences are discussed.

Interaction with the lower ionosphere of electromagnetic pulses from lightning - Heating, attachment, and ionization

Science.gov (United States)

Taranenko, Y. N.; Inan, U. S.; Bell, T. F.

1993-01-01

A Boltzmann formulation of the electron distribution function and Maxwell's equations for the EM fields are used to simulate the interaction of lightning radiated EM pulses with the lower ionosphere. Ionization and dissociative attachment induced by the heated electrons cause significant changes in the local electron density, N(e). Due to 'slow' field changes of typical lightning EM pulses over time scales of tens of microsec, the distribution function follows the quasi-equilibrium solution of the Boltzmann equation in the altitude range of interest (70 to 100 km). The EM pulse is simulated as a planar 100 microsec long single period oscillation of a 10 kHz wave injected at 70 km. Under nighttime conditions, individual pulses of intensity 10-20 V/m (normalized to 100 km horizontal distance) produce changes in N(e) of 1-30 percent while a sequence of pulses leads to strong modification of N(e) at altitudes less than 95 km. The N(e) changes produce a 'sharpening' of the lower ionospheric boundary by causing a reduction in electron density at 75-85 km (due to attachment) and a substantial increase at 85-95 km (due to ionization) (e.g., the scale height decreases by a factor of about 2 at about 85 km for a single 20 V/m EM pulse). No substantial N(e) changes occur during daytime.

Attachment Security and Pain

DEFF Research Database (Denmark)

Andersen, Tonny Elmose; Lahav, Yael; Defrin, Ruth

2015-01-01

The present study assesses for the first time, the possible disruption effect of posttraumatic stress symptoms (PTSS) with regard to the protective role of attachment on pain, among ex-POWs. While secure attachment seems to serve as a buffer, decreasing the perception of pain, this function may...

Attachment and Temperament Revisited: Infant Distress, Attachment Disorganization, and the Serotonin Transporter Polymorphism.

Science.gov (United States)

Brumariu, Laura E; Bureau, Jean-François; Nemoda, Zsofia; Sasvari-Szekely, Maria; Lyons-Ruth, Karlen

This study's aim was to evaluate whether infant disorganized attachment and infant proneness to distress exhibited differential relations to infant genetic factors as indexed by the serotonin transporter polymorphism. The role of the short allele of the serotonin transporter polymorphism (5-HTTLPR) in enhancing sensitivity to fearful and negative affect has been well-established (Canli & Lesch, 2007). In the current study, we used this known property of the short allele to provide a test of an important postulate of attachment theory, namely that infant attachment security or disorganization is not a function of the infant's proneness to distress. Participants were 39 parents and infants assessed between 12 and 18 months in the Strange Situation procedure. Genotype categories for the 5-HTTLPR (and rs25531) were created by both the original and the reclassified grouping system; infant proneness to distress was assessed directly in the Strange Situation Procedure. We also assessed maternal behavior at 18 months to evaluate whether any observed genetic effect indicated a passive effect through the mother. Consistent with previous findings, the 5-HTTLPR short allele was significantly related to the infant's wariness and distress, but was not related to attachment security or attachment disorganization. In addition, maternal disrupted interaction with the infant was not related to infant genotype or infant distress. Results support the concept that infant proneness to distress is associated with serotonergic factors while infant attachment security or disorganization is not a function of either 5-HTTLPR or behaviorally rated proneness to distress.

Excessive sensitivity of momentum densities to crystal potentials as a reason for difficulties in verifying positron enhancement theories

International Nuclear Information System (INIS)

Sormann, H.

2001-01-01

The excessive sensitivity of the momentum densities of electron-positron annihilation pairs (MDAP) to crystal potentials found in this study severely deteriorates a possibility to use a comparison between theoretical and experimental MDAP results as a criterion for the legitimacy of electron-positron interaction theories. Illustrative examples are given. (orig.)

Temperament and attachment: one construct or two?

Science.gov (United States)

Mangelsdorf, S C; Frosch, C A

1999-01-01

In this chapter we described the constructs of temperament and attachment and have discussed similarities and differences between the two. We addressed the issue of whether temperament contributes to overall attachment security or to the specific type of attachment that children display. We conclude that although temperament may influence the type of secure and insecure attachment relationship children form with their parent, temperament alone will not determine if a child is classified as securely or insecurely attached. We presented evidence suggesting that certain dimensions of temperament, specifically negative emotionality, may be associated with infants' behavior during the Strange Situation, such as proneness-to-distress during separations. However, we noted that these temperament dimensions do not predict overall security of attachment. It is likely that although no single temperament characteristic, such as proneness-to-distress, in and of itself determines overall attachment security, it is possible that a constellation of temperament characteristics may be more strongly related to attachment security. The examination of constellations of temperament characteristics may be particularly useful for furthering our understanding of individual differences within attachment classifications. Such an approach may elucidate the reasons why infants are classified into one subgroup of secure, insecure-avoidant, or insecure-resistant attachment versus another subgroup. Furthermore, we suggest that the collection of findings regarding temperament and attachment not only underscores the importance of a transactional approach to early social-emotional development, but emphasizes that temperament and attachment can make unique and interactive contributions to children's social-emotional functioning. That is, the goodness-of-fit between infant and parent characteristics may best predict security of attachment. Although child characteristics clearly contribute to the

34 CFR 300.16 - Excess costs.

Science.gov (United States)

2010-07-01

... 34 Education 2 2010-07-01 2010-07-01 false Excess costs. 300.16 Section 300.16 Education... DISABILITIES General Definitions Used in This Part § 300.16 Excess costs. Excess costs means those costs that... for an example of how excess costs must be calculated.) (Authority: 20 U.S.C. 1401(8)) ...

To attach or not to attach? The effect of carrier surface morphology and topography on attachment of phoretic deutonymphs of Uropoda orbicularis (Acari)

Science.gov (United States)

Bajerlein, Daria; Adamski, Zbigniew; Kacalak, Wojciech; Tandecka, Katarzyna; Wiesner, Maciej; Jurga, Stefan

2016-08-01

Previous studies on preferences of phoretic deutonymphs of Uropodina for attachment sites have shown that they frequently select smooth and hydrophobic surfaces. The aim of our study was to provide the detailed morphological and topographical characteristics of beetle body surfaces to which deutonymphs frequently attach and to verify how the presence of setae and surface sculpture affects deutonymph attachment. The study was conducted on Uropoda orbicularis (Müller, 1776) and its common beetle carriers: Aphodius prodromus (Brahm, 1790), Aphodius fimetarius (Linnaeus, 1758), Onthophagus nuchicornis (Linnaeus, 1758) and Margarinotus carbonarius (Hoffmann, 1803). Morphology and topography of elytra, femora, propygidia and pygidia of beetles were analysed mainly using SEM methods supported with CLSM and AFM techniques. The hypothesis that deutonymphs may attach to surfaces covered with setae, if seta density is low enough not to disturb mite movement, was tested. The study revealed that deutonymphs attach to surfaces of various types as follows: (i) smooth, (ii) hairy, i.e., covered with setae, (iii) flat and (iv) sculptured. Smooth body parts and body parts covered with setae of low density were most frequently and intensively occupied with deutonymphs. Surfaces of high seta density were avoided by mites. Within elytra of Aphodius beetles, deutonymphs definitely preferred flat surfaces of elytral intervals. On the contrary, densely punctuated propygidium and pygidium in M. carbonarius were heavily infested with deutonymphs. We conclude that carrier surface morphology and topography are important for Uropodina deutonymph attachment, but these two factors cannot fully explain the observed relation.

Bond-equilibrium theory of liquid Se-Te alloys. II. Effect of singly attached ring molecules

Science.gov (United States)

Cutler, Melvin; Bez, Wolfgang G.

1981-06-01

A statistical-mechanical theory for bond equilibrium of chain polymers containing threefold (3F) and onefold (1F) bond defects is extended to include the effects of free ring molecules and ring molecules attached to chains by a single 3F atom. Positively charged singly attached rings are shown to play a key role in bond equilibrium in liquid Sex Te1-x by permitting the formation of ion pairs in which both constituents are effectively chain terminators, thus decreasing the average polymer size. The theory is applied to explain the behavior of the paramagnetic susceptibility, χp, and electronic transport as affected by the Fermi energy EF. It is found that the increase in χp with the concentration of Te is primarily the result of the smaller energy for breaking Te bonds. In addition, attached rings play an important role in determining the effect of temperature on χp. At x<~0.5, the concentrations of both free and attached rings becomes small at high T because of the high concentration of bond defects.

Attachment Theory and Mindfulness

Science.gov (United States)

Snyder, Rose; Shapiro, Shauna; Treleaven, David

2012-01-01

We initiate a dialog between two central areas in the field of psychology today: attachment theory/research and mindfulness studies. The impact of the early mother-infant relationship on child development has been well established in the literature, with attachment theorists having focused on the correlation between a mother's capacity for…

Breastfeeding, Parenting, and Infant Attachment Behaviors.

Science.gov (United States)

Gibbs, Benjamin G; Forste, Renata; Lybbert, Emily

2018-04-01

Objectives Infants and toddlers need secure attachments in order to develop the social competence required to successfully navigate later peer and adult relationships. Breastfeeding is a parenting factor that has been associated with child emotional development-specifically the attachment between children and their mothers. Yet, this link may simply be the result of other parenting behaviors that are associated with breastfeeding. Thus, our objective is to examine whether the link between infant attachment behaviors and breastfeeding endures when accounting for a broad array of in-depth measures of parenting. Methods We use the Early Childhood Longitudinal Study of children from 9 months to 2 years of age collected by the National Center for Education Statistics. Using Ordinary Least Squares regression, data analyses examine the association between the Toddler Attachment Sort-45 (TAS-45) measures of toddler-parent attachment (infant attachment security and temperamental dependency) and breastfeeding practices. We also examine individual items of the TAS-45 to isolate specific attachment behaviors that have the strongest associations with breastfeeding. Results We find an enduring link between children who are predominantly breastfed for six or more months and infant attachment security. However, we find no evidence that breastfeeding is linked to a child's temperamental dependency. Of the nine items used to examine infant attachment behaviors, we find that breastfed children are rated as having slightly higher scores on two measures ("warm and cuddly," "cooperative") and lower scores on one measure ("demanding/angry"). Conclusions for Practice Breastfeeding has an important link to the child's use of their caregiver as a secure base for exploration and a place of comfort when distressed (infant attachment security). Yet, breastfeeding does not appear to reduce a child's temperamental dependency or level of clinginess as measured by how demanding, fussy or

Adolescents' multiple versus single primary attachment figures, reorganization of attachment hierarchy, and adjustments: the important people interview approach.

Science.gov (United States)

Umemura, Tomotaka; Lacinová, Lenka; Kraus, Jakub; Horská, Eliška; Pivodová, Lenka

2018-04-20

Using 212 adolescents from a central-European country (mean age = 14.02, SD = 2.05, ranged from 11 to 18 years; females = 54%) and a multi-informant method to measure adolescents' behavioral and emotional adjustments, the present study explored three aspects regarding the attachment hierarchy. (1) The three types of behavioral systems of Rosenthal and Kobak's important people interview (IPI) were initially validated using an exploratory factor analysis with a US sample. Using a confirmatory factor analysis with a Czech sample, we replicated these three behavioral systems: attachment bond, support seeking, and affiliation. (2) We found that adolescents who developed attachment bond to multiple primary attachment figures were likely to score lower on both teacher-rated and parent-rated internalizing problems compared to those who had a single primary attachment figure. These multiple primary attachment figures tended to be family members (not peers). (3) Early adolescents who placed parents low in their attachment hierarchy scored higher on self-reported negative affect and lower on self-reported positive affect compared to early adolescents who placed parents high. The present study highlights multiple (vs. single) primary attachment figures as a protective factor and the premature reorganization of attachment hierarchy as a risk factor for adolescents' emotional and affective adjustments.

Some aspects of electron dynamics in solid alkanes

International Nuclear Information System (INIS)

Cheng, I.I.; Funabashi, K.

1975-01-01

The excess electron mobility in 3-methylpentane (3MP) is in the range of 0.02-0.1 cm 2 /v.s. for 4.2-85 0 K. The mobility is nearly independent of temperature below 35 0 K, while the activation energy is about 0.01 eV for 35 0 K-85 0 K. The magnitude of mobility and its temperature dependence are consistent with the hopping and tunneling motion of electron between trapped (or localized) states. The decay kinetics of the absorption spectrum of trapped electrons in 3MP also suggest the presence of many trapping sites, and a small mean free path of retrapping for a quasi-free electron. It is conjectured that the electron-transport in 3MP glass is the phonon-assisted hopping or tunneling and the mean free path (or the mobility) at the quasi-free state is not as large as 100 A (or 150 cm 2 /v.s.). The mean free path of scattering for an excess electron at the quasi-free level in various alkane glasses can be found approximately from measurement of attenuation constants for electron beams (Chang and Berry). The relationship of these attenuation constants with V 0 (quasi-free state) will be discussed. The effect of electron-phonon coupling on the effective mass of excess electrons will also be discussed in terms of a simple model. The effective mass is a sensitive function of the ratio of the relaxation energy to the phonon energy

Specific features of the behaviour of excess currents in tunnel diodes of n-GaAs

International Nuclear Information System (INIS)

Vyatkin, A.P.; Glushchenko, V.A.; Parkhomenko, R.P.; Pastor, A.P.

1981-01-01

The behaviour of currents in the field of a valley of volt-ampere characteristics (VAC) and the effect of 2.0 MeV electron bombardment on the characteristics of tunnel n-GaAs of TD diodes is considered. Release of tunnel and thermal current components has shown that the first component of excess currents is due to electron tunneling through intermediate states situated in a wide region of the forbidden zone. The nature of the second current component is explained by far reaching into the region of the forbidden zone tails of electron states on which energy impurity states can superimpose. Highly-alloyed TD with concentrations n>=3x10 19 cm -3 and p=(1.5-2)x10 20 cm -3 practically are not sensitive to doses up to phi approximately 2x10 17 el/cm 2 . Radiation induced defects related with electron bombardment is rather small. Specific features of the preparation of n-GaAs tunnel diodes lead to the fact that as a result of complex alloying of the p-region of the diode a relatively slow increase of excess currents as compared with the TD corresponding currents from the p-GaAs is observed

Water network-mediated, electron-induced proton transfer in [C{sub 5}H{sub 5}N ⋅ (H{sub 2}O){sub n}]{sup −} clusters

Energy Technology Data Exchange (ETDEWEB)

DeBlase, Andrew F.; Wolke, Conrad T.; Johnson, Mark A., E-mail: jordan@pitt.edu, E-mail: nhammer@olemiss.edu, E-mail: mark.johnson@yale.edu [Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520 (United States); Weddle, Gary H. [Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520 (United States); Department of Chemistry, Fairfield University, 1073 North Benson Road, Fairfield, Connecticut 06824 (United States); Archer, Kaye A.; Jordan, Kenneth D., E-mail: jordan@pitt.edu, E-mail: nhammer@olemiss.edu, E-mail: mark.johnson@yale.edu [Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260 (United States); Kelly, John T.; Tschumper, Gregory S.; Hammer, Nathan I., E-mail: jordan@pitt.edu, E-mail: nhammer@olemiss.edu, E-mail: mark.johnson@yale.edu [Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677 (United States)

2015-10-14

The role of proton-assisted charge accommodation in electron capture by a heterocyclic electron scavenger is investigated through theoretical analysis of the vibrational spectra of cold, gas phase [Py ⋅ (H{sub 2}O){sub n=3−5}]{sup −} clusters. These radical anions are formed when an excess electron is attached to water clusters containing a single pyridine (Py) molecule in a supersonic jet ion source. Under these conditions, the cluster ion distribution starts promptly at n = 3, and the photoelectron spectra, combined with vibrational predissociation spectra of the Ar-tagged anions, establish that for n > 3, these species are best described as hydrated hydroxide ions with the neutral pyridinium radical, PyH{sup (0)}, occupying one of the primary solvation sites of the OH{sup −}. The n = 3 cluster appears to be a special case where charge localization on Py and hydroxide is nearly isoenergetic, and the nature of this species is explored with ab initio molecular dynamics calculations of the trajectories that start from metastable arrangements of the anion based on a diffuse, essentially dipole-bound electron. These calculations indicate that the reaction proceeds via a relatively slow rearrangement of the water network to create a favorable hydration configuration around the water molecule that eventually donates a proton to the Py nitrogen atom to yield the product hydroxide ion. The correlation between the degree of excess charge localization and the evolving shape of the water network revealed by this approach thus provides a microscopic picture of the “solvent coordinate” at the heart of a prototypical proton-coupled electron transfer reaction.

Observation of Zero-Dimensional States in a One-Dimensional Electron Interferometer

NARCIS (Netherlands)

Wees, B.J. van; Kouwenhoven, L.P.; Harmans, C.J.P.M.; Williamson, J.G.; Timmering, C.E.; Broekaart, M.E.I.; Foxon, C.T.; Harris, J.J.

1989-01-01

We have studied the electron transport in a one-dimensional electron interferometer. It consists of a disk-shaped two-dimensional electron gas, to which quantum point contacts are attached. Discrete zero-dimensional states are formed due to constructive interference of electron waves traveling along

Attachment theory: A review of research

Directory of Open Access Journals (Sweden)

Polovina Nada

2005-01-01

Full Text Available Research of attachment is numerous and versatile. They differ according to problems addressed, methodology applied (longitudinal studies, studies with horizontal designs, different instruments used, different methods of data analysis, and characteristics of samples involved (concerning age socio/economic status, family ecology. The research is commonly relied on the core assumptions of the theory itself, and the shared characteristic is orientation to explore complex phenomena of human experience and functioning. From the vast variety of research only those who most directly test the basic assumptions of the attachment theory are focused and addressed in the paper: representation of patterns of attachment in the childhood and adulthood, stability and change of attachment security from infancy to early adulthood, transgenerational transmission of attachment characteristics, the place and the role of attachment behavioral system in the personality development. The aim of the paper is to highlight the basic research and theory issues and directions, and illustrate them with concrete research date.

Attachment style and interpersonal trauma in refugees.

Science.gov (United States)

Morina, Naser; Schnyder, Ulrich; Schick, Matthis; Nickerson, Angela; Bryant, Richard A

2016-12-01

Refugees can suffer many experiences that threaten their trust in others. Although models of refugee mental health have postulated that attachment securities may be damaged by refugee experiences, this has yet to be empirically tested. This study aimed to understand the relationship between the nature of traumatic experiences sustained by refugees and attachment styles. In a cross-sectional study, treatment-seeking refugees (N = 134) were assessed for traumatic exposure using the Harvard Trauma Questionnaire and Posttraumatic Diagnostic Scale. Attachment style was assessed using the Experiences in Close Relationship Scale. Whereas gender and severity of interpersonal traumatic events predicted avoidant attachment style (accounting for 11% of the variance), neither these factors nor non-interpersonal trauma predicted anxious attachment. Exposure to interpersonal traumatic events, including torture, is associated with enduring avoidant attachment tendencies in refugees. This finding accords with attachment theories that prior adverse interpersonal experiences can undermine secure attachment systems, and may promote avoidance of attachment seeking. This finding may point to an important process maintaining poor psychological health in refugees affected by interpersonal trauma. © The Royal Australian and New Zealand College of Psychiatrists 2016.

Excessive or unwanted hair in women

Science.gov (United States)

Hypertrichosis; Hirsutism; Hair - excessive (women); Excessive hair in women; Hair - women - excessive or unwanted ... Women normally produce low levels of male hormones (androgens). If your body makes too much of this ...

Attachment representation in institutionalized children: a preliminary study using the child attachment interview.

Science.gov (United States)

Zaccagnino, Maria; Cussino, Martina; Preziosa, Alessandra; Veglia, Fabio; Carassa, Antonella

2015-01-01

The experience of being removed from one's home and the transition to a residential care system pose enormous challenges for a child. Substantial evidence has been found regarding severe developmental effects due to early exposition to extreme psychosocial and affective deprivation. The research on Bowlby's theoretical proposals has highlighted the link between insecure, disorganized and atypical attachment patterns and children both living in foster care facilities and adopted out of those institutions. The goal of this pilot study is to investigate the attachment representation in an Italian sample of children in middle childhood (9-13 years old) who have been removed from their homes. Two compared groups of children participated in this study. The first group was composed of 24 Italian children who had been removed from their homes. The second group, considered as the control group, was composed of 35 Italian children who had never been in foster care placement. The quality of children's attachment to their primary caregivers was assessed by the Child Attachment Interview, an innovative semi-structured interview that seeks to bridge the measurement gap identified in middle childhood The children in foster care placement show a higher percentage of insecure and disorganized attachment representations and lower scores on the Child Reflective Functioning Scale. The clinical implications and enhancements to effective intervention for foster children's caretaking are discussed. Copyright © 2014 John Wiley & Sons, Ltd.

What do we know about maternal-fetal attachment?

Science.gov (United States)

Shieh, C; Kravitz, M; Wang, H H

2001-09-01

A review of the literature suggests that there are three critical attributes related to the concept of maternal-fetal attachment, including cognitive, affective, and altruistic attachment. Cognitive attachment is the desire to know the baby. Affective attachment is the pleasure associated with thoughts of or interaction with the fetus. Altruistic attachment refers to a desire to protect the unborn child. Existing measurements on maternal-fetal attachment are developed based on low-risk and white pregnant women and previous research has not yet resulted in a consistent theoretical model. Future research should focus on development of culturally sensitive instruments and combining qualitative and quantitative measures to broaden theoretical understanding of the concept. Nursing assessment of maternal-fetal attachment is an on-going process. The nurse's role is to reassure those who have developed attachment to their fetuses and to motivate those who are unaware of or unconcerned about their attachment to their fetuses. Collecting data from different attributes of attachment helps nurses identify each woman's attachment patterns and areas of concern.

Direct comparison of phosphate uptake by adnate and loosely attached microalgae within an intact biofilm matrix

International Nuclear Information System (INIS)

Burkholder, J.M.; Wetzel, R.G.; Klomparens, K.L.

1990-01-01

We report a direct comparison of phosphate uptake by adnate and loosely attached microalgae in an intact biofilm matrix, with resolution at the level of individual cells. Track scanning electron microscope autoradiography enabled assay of [ 33 P]phosphate uptake from the overlying water by adnate algae left undisturbed on mature leaves of the macrophyte Potamogeton illinoensis or on artificial plant mimics. The epiphyte communities developed in either phosphate-poor or moderately phosphate-enriched water, and they were assayed on both natural and artificial plants. All adnate taxa examined from both natural and artificial plants in both habitats took up significantly less radiolabel when assayed beneath the overlying matrix than when they were exposed to the water upon removal of the overstory material. Track scanning electron microscope autoradiography and track light microscope autoradiography were intercalibrated to enable comparison of [ 33 P]phosphate uptake by adnate and loosely attached components of the epiphyte matrix. Loosley attached cells on substrata from both habitats took up significantly more radiolabel than did underlying adnate cells, indicating that access to phosphate supplies from the water depended on the position of microbial cells in the matrix. In this short-term assay, the adnate microalgae were relatively isolated from the water column nutrient source

Attachment Styles of Dermatological Patients in Europe

DEFF Research Database (Denmark)

Szabó, Csanád; Altmayer, Anita; Lien, Lars

2017-01-01

Attachment styles of dermatological outpatients and satisfaction with their dermatologists were investigated within the framework of a multicentre study conducted in 13 European countries, organized by the European Society for Dermatology and Psychiatry. Attachment style was assessed with the Adult......, and experienced similar rates of anxiety in relationships as did the controls. Participants who had secure attachment styles reported stressful life events during the last 6 months significantly less often than those who had insecure attachment styles. Patients with secure attachment styles tended to be more...... satisfied with their dermatologist than did insecure patients. These results suggest that secure attachment of dermatological outpatients may be a protective factor in the management of stress....

Ion-Ion Plasmas Produced by Electron Beams

Science.gov (United States)

Fernsler, R. F.; Leonhardt, D.; Walton, S. G.; Meger, R. A.

2001-10-01

The ability of plasmas to etch deep, small-scale features in materials is limited by localized charging of the features. The features charge because of the difference in electron and ion anisotropy, and thus one solution now being explored is to use ion-ion plasmas in place of electron-ion plasmas. Ion-ion plasmas are effectively electron-free and consist mainly of positive and negative ions. Since the two ion species behave similarly, localized charging is largely eliminated. However, the only way to produce ion-ion plasmas at low gas pressure is to convert electrons into negative ions through two-body attachment to neutrals. While the electron attachment rate is large at low electron temperatures (Te < 1 eV) in many of the halogen gases used for processing, these temperatures occur in most reactors only during the afterglow when the heating fields are turned off and the plasma is decaying. By contrast, Te is low nearly all the time in plasmas produced by electron beams, and therefore electron beams can potentially produce ion-ion plasmas continuously. The theory of ion-ion plasmas formed by pulsed electron beams is examined in this talk and compared with experimental results presented elsewhere [1]. Some general limitations of ion-ion plasmas, including relatively low flux levels, are discussed as well. [1] See the presentation by D. Leonhardt et al. at this conference.

Ionization in liquids

International Nuclear Information System (INIS)

Bakale, G.

1990-01-01

During the 1987--1990 reporting period, studies were conducted that entailed the direct measurement of the transport and reaction properties of excess electrons in nonpolar liquids through the use of pulse-conductivity techniques. The results obtained from these studies should be applicable toward the development of a better understanding of the primary ionizing event in liquids as well as to providing physico-chemical information that is pertinent to electron-transfer processes that are ubiquitous in biological systems. Progress was also made in developing a better understanding of electron attachment reactions in liquids through measurements of the electron attachment rate constants, k e s, of a variety of electron-attaching solutes. The effects of several functional groups substituted at different positions on benzene were studied in liquid cyclohexane and isooctane. The electron-attaching properties of chemicals having well characterized carcinogenic properties were studied in cyclohexane to determine if the measure of electron-accepting potential that k e provides can elucidate the role that electrons play in the initiation step of carcinogenesis. The k e s that were measured indicate that the k e -carcinogenicity correlation that was observed can be used to complement short-term carcinogen-screening bioassays to identify potential carcinogens. 115 refs., 6 tabs

Excessive growth.

Science.gov (United States)

Narayanaswamy, Vasudha; Rettig, Kenneth R; Bhowmick, Samar K

2008-09-01

Tall stature and excessive growth syndrome are a relatively rare concern in pediatric practice. Nevertheless, it is important to identify abnormal accelerated growth patterns in children, which may be the clue in the diagnosis of an underlying disorder. We present a case of pituitary gigantism in a 2 1/2-year-old child and discuss the signs, symptoms, laboratory findings, and the treatment. Brief discussions on the differential diagnosis of excessive growth/tall stature have been outlined. Pituitary gigantism is very rare in the pediatrics age group; however, it is extremely rare in a child that is less than 3 years of age. The nature of pituitary adenoma and treatment options in children with this condition have also been discussed.

Pulse radiolytic and electrochemical investigations of intramolecular electron transfer in carotenoporphyrins and carotenoporphyrin-quinone triads

International Nuclear Information System (INIS)

Land, E.J.; Lexa, D.; Bensasson, R.V.; Gust, D.; Moore, T.A.; Moore, A.L.; Liddell, P.A.; Nemeth, G.A.

1987-01-01

Thermodynamic and kinetic aspects of intramolecular electron-transfer reactions in carotenoporphyrin dyads and carotenoid-porphyrin-quinone triads have been studied by using pulse radiolysis and cyclic voltammetry. Rapid (<1 μs) electron transfer from carotenoid radical anions to attached porphyrins has been inferred. Carotenoid cations, on the other hand, do not readily accept electrons from attached porphyrins or pyropheophorbides. Electrochemical studies provide the thermodynamic basis for these observations and also allow estimation of the energetics of photoinitiated two-step electron transfer and two-step charge recombination in triad models for photosynthetic charge separation

Within-person variation in security of attachment: a self-determination theory perspective on attachment, need fulfillment, and well-being.

Science.gov (United States)

La Guardia, J G; Ryan, R M; Couchman, C E; Deci, E L

2000-09-01

Attachment research has traditionally focused on individual differences in global patterns of attachment to important others. The current research instead focuses primarily on within-person variability in attachments across relational partners. It was predicted that within-person variability would be substantial, even among primary attachment figures of mother, father, romantic partner, and best friend. The prediction was supported in three studies. Furthermore, in line with self-determination theory, multilevel modeling and regression analyses showed that, at the relationship level, individuals' experience of fulfillment of the basic needs for autonomy, competence, and relatedness positively predicted overall attachment security, model of self, and model of other. Relations of both attachment and need satisfaction to well-being were also explored.

The Effect of Ag and Ag+N Ion Implantation on Cell Attachment Properties

International Nuclear Information System (INIS)

Urkac, Emel Sokullu; Oztarhan, Ahmet; Gurhan, Ismet Deliloglu; Iz, Sultan Gulce; Tihminlioglu, Funda; Oks, Efim; Nikolaev, Alexey; Ila, Daryush

2009-01-01

Implanted biomedical prosthetic devices are intended to perform safely, reliably and effectively in the human body thus the materials used for orthopedic devices should have good biocompatibility. Ultra High Molecular Weight Poly Ethylene (UHMWPE) has been commonly used for total hip joint replacement because of its very good properties. In this work, UHMWPE samples were Ag and Ag+N ion implanted by using the Metal-Vapor Vacuum Arc (MEVVA) ion implantation technique. Samples were implanted with a fluency of 1017 ion/cm2 and extraction voltage of 30 kV. Rutherford Backscattering Spectrometry (RBS) was used for surface studies. RBS showed the presence of Ag and N on the surface. Cell attachment properties investigated with model cell lines (L929 mouse fibroblasts) to demonstrate that the effect of Ag and Ag+N ion implantation can favorably influence the surface of UHMWPE for biomedical applications. Scanning electron microscopy (SEM) was used to demonstrate the cell attachment on the surface. Study has shown that Ag+N ion implantation represents more effective cell attachment properties on the UHMWPE surfaces.

Systematic design of active spaces for multi-reference calculations of singlet-triplet gaps of organic diradicals, with benchmarks against doubly electron-attached coupled-cluster data

Science.gov (United States)

Stoneburner, Samuel J.; Shen, Jun; Ajala, Adeayo O.; Piecuch, Piotr; Truhlar, Donald G.; Gagliardi, Laura

2017-10-01

Singlet-triplet gaps in diradical organic π-systems are of interest in many applications. In this study, we calculate them in a series of molecules, including cyclobutadiene and its derivatives and cyclopentadienyl cation, by using correlated participating orbitals within the complete active space (CAS) and restricted active space (RAS) self-consistent field frameworks, followed by second-order perturbation theory (CASPT2 and RASPT2). These calculations are evaluated by comparison with the results of doubly electron-attached (DEA) equation-of-motion (EOM) coupled-cluster (CC) calculations with up to 4-particle-2-hole (4p-2h) excitations. We find active spaces that can accurately reproduce the DEA-EOMCC(4p-2h) data while being small enough to be applicable to larger organic diradicals.

Fuel rod attachment system

International Nuclear Information System (INIS)

Christiansen, D.W.

1982-01-01

A reusable system for removably attaching a nuclear reactor fuel rod to a support member. A locking cap is secured to the fuel rod and a locking strip is fastened to the support member or vice versa. The locking cap has two opposing fingers and shaped to form a socket having a body portion. The locking strip has an extension shaped to rigidly attach to the socket's body portion. The locking cap's fingers are resiliently deflectable. For attachment, the locking cap is longitudinally pushed onto the locking strip causing the extension to temporarily deflect open the fingers to engage the socket's body portion. For removal, the process is reversed. In an alternative embodiment, the cap is rigid and the strip is transversely resiliently compressible. (author)

It takes two to talk: longitudinal associations among infant-mother attachment, maternal attachment representations, and mother-child emotion dialogues.

Science.gov (United States)

Hsiao, Celia; Koren-Karie, Nina; Bailey, Heidi; Moran, Greg

2015-01-01

Research on the attachment-dialogue link has largely focused on infant-mother attachment. This study investigated longitudinal associations between infant-mother attachment and maternal attachment representations and subsequent mother-child emotion dialogues (N = 50). Maternal attachment representations were assessed using the Adult Attachment Interview when children were 3 months, infant-mother attachment was assessed using the Strange Situation Procedure at 13 months, and mother-child emotion dialogues were assessed using the Autobiographical Emotional Events Dialogue at 3.5 years. Consistent with past research, the three organized categories of infant-mother attachment relationships were associated with later mother-child emotion dialogues. Disorganized attachment relationships were associated with a lack of consistent and coherent strategy during emotion dialogues. Autonomous mothers co-constructed coherent narratives with their children; Dismissing and Preoccupied mothers created stories that were less narratively organized. Although the Unresolved category was unrelated to classifications of types of mother-child discourse, mothers' quality of contribution to the dialogues was marginally lower compared to the quality of their children's contributions to the emotion discussion. Secure children showed highest levels of child cooperation and exploration. Autonomous mothers displayed highest levels of maternal sensitive guidance during emotion dialogues. We provide preliminary evidence for role reversal in dialogues between Preoccupied and Unresolved mothers and their children.

Insecure attachment behavior and partner violence: incorporating couple perceptions of insecure attachment and relational aggression.

Science.gov (United States)

Oka, Megan; Sandberg, Jonathan G; Bradford, Angela B; Brown, Andrew

2014-10-01

Intimate partner violence and insecure attachment are therapeutically relevant concepts when working with couples. The link between attachment and intimate partner violence has been examined in the literature, but an area of aggression that often goes unexamined is relational aggression, or using third parties as a means of being aggressive toward a partner. We asked how participants' attachment behaviors were related to their own and partners' relational and physical aggression. We used structural equation modeling to estimate actor-partner interdependence among these relationships in 644 heterosexual couples. Results indicated significant partner paths from attachment to relational aggression, as well as significant actor paths between relational aggression and physical aggression. Implications were discussed. Data for this study were collected from the RELATE assessment. © 2014 American Association for Marriage and Family Therapy.

Thermodynamic properties of binary mixtures of tetrahydropyran with pyridine and isomeric picolines: Excess molar volumes, excess molar enthalpies and excess isentropic compressibilities

International Nuclear Information System (INIS)

Saini, Neeti; Jangra, Sunil K.; Yadav, J.S.; Sharma, Dimple; Sharma, V.K.

2011-01-01

Research highlights: → Densities, ρ and speeds of sound, u of tetrahydropyran (i) + pyridine or α-, β- or γ-picoline (j) binary mixtures at 298.15, 303.15 and 308.15 K and excess molar enthalpies, H E of the same set of mixtures at 308.15 K have been measured as a function of composition. → The observed densities and speeds of sound values have been employed to determine excess molar volumes, V E and excess isentropic compressibilities, κ S E . → Topology of the constituents of mixtures has been utilized (Graph theory) successfully to predict V E , H E and κ S E data of the investigated mixtures. → Thermodynamic data of the various mixtures have also been analyzed in terms of Prigogine-Flory-Patterson (PFP) theory. - Abstract: Densities, ρ and speeds of sound, u of tetrahydropyran (i) + pyridine or α-, β- or γ- picoline (j) binary mixtures at 298.15, 303.15 and 308.15 K and excess molar enthalpies, H E of the same set of mixtures at 308.15 K have been measured as a function of composition using an anton Parr vibrating-tube digital density and sound analyzer (model DSA 5000) and 2-drop micro-calorimeter, respectively. The resulting density and speed of sound data of the investigated mixtures have been utilized to predict excess molar volumes, V E and excess isentropic compressibilities, κ S E . The observed data have been analyzed in terms of (i) Graph theory; (ii) Prigogine-Flory-Patterson theory. It has been observed that V E , H E and κ S E data predicted by Graph theory compare well with their experimental values.

Excess wind power

DEFF Research Database (Denmark)

Østergaard, Poul Alberg

2005-01-01

Expansion of wind power is an important element in Danish climate change abatement policy. Starting from a high penetration of approx 20% however, momentary excess production will become an important issue in the future. Through energy systems analyses using the EnergyPLAN model and economic...... analyses it is analysed how excess productions are better utilised; through conversion into hydrogen of through expansion of export connections thereby enabling sales. The results demonstrate that particularly hydrogen production is unviable under current costs but transmission expansion could...

75 FR 27572 - Monthly Report of Excess Income and Annual Report of Uses of Excess Income

Science.gov (United States)

2010-05-17

... Income and Annual Report of Uses of Excess Income AGENCY: Office of the Chief Information Officer, HUD... permitted to retain Excess Income for projects under terms and conditions established by HUD. Owners must request to retain some or all of their Excess Income. The request must be submitted through http://www.pay...

Superconductors with excess quasiparticles

International Nuclear Information System (INIS)

Elesin, V.F.; Kopaev, Y.V.

1981-01-01

This review presents a systematic kinetic theory of nonequilibrium phenomena in superconductors with excess quasiparticles created by electromagnetic or tunnel injection. The energy distributions of excess quasiparticles and of nonequilibrium phonons, dependence of the order parameter on the power and frequency (or intensity) of the electromagnetic field, magnetic properties of nonequilibrium superconductors, I-V curves of superconductor-insulator-superconductor junctions, and other properties are described in detail. The stability of superconducting states far from thermodynamic equilibrium is investigated and it is shown that characteristic instabilities leading to the formation of nonuniform states of a new type or phase transitions of the first kind are inherent to superconductors with excess quasiparticles. The results are compared with experimental data

Lithium-Excess Research of Cathode Material Li2MnTiO4 for Lithium-Ion Batteries

OpenAIRE

Zhang, Xinyi; Yang, Le; Hao, Feng; Chen, Haosen; Yang, Meng; Fang, Daining

2015-01-01

Lithium-excess and nano-sized Li2+xMn1−x/2TiO4 (x = 0, 0.2, 0.4) cathode materials were synthesized via a sol-gel method. The X-ray diffraction (XRD) experiments indicate that the obtained main phases of Li2.0MnTiO4 and the lithium-excess materials are monoclinic and cubic, respectively. The scanning electron microscope (SEM) images show that the as-prepared particles are well distributed and the primary particles have an average size of about 20–30 nm. The further electrochemical tests revea...

Multiple electron generation in a sea of electronic states

Science.gov (United States)

Witzel, Wayne; Shabaev, Andrew; Efros, Alexander; Hellberg, Carl; Verne, Jacobs

2009-03-01

In traditional bulk semiconductor photovoltaics (PVs), each photon may excite a single electron-hole, wasting excess energy beyond the band-gap as heat. In nanocrystals, multiple excitons can be generated from a single photon, enhancing the PV current. Multiple electron generation (MEG) may result from Coulombic interactions of the confined electrons. Previous investigations have been based on incomplete or over-simplified electronic-state representations. We present results of quantum simulations that include hundreds of thousands of configuration states and show how the complex dynamics, even in a closed electronic system, yields a saturated MEG effect on a femtosecond timescale. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Attachment-based interventions for families with young children.

Science.gov (United States)

Woodhouse, Susan S

2018-05-21

Given a large body of research indicating links between child attachment and later mental health outcomes, interventions that promote children's secure attachment to their caregivers have the potential to contribute to prevention of psychopathology and promotion of well-being. A number of attachment-based interventions have been developed to support parents, enhance caregiving quality, and promote children's attachment security with the aim of improving children's mental health. There is now a growing evidence base to support the efficacy of a number of these interventions. The present literature review and introduction to the special issue on attachment-based interventions for families with young children describes key aspects of attachment theory and research that form the theoretical and empirical background for attachment-based interventions, and introduces seven case studies illustrating five different attachment-based interventions. The case studies represent a variety of attachment-based models, including both group and individual treatments, and show applications across a range of caregiver contexts. © 2018 Wiley Periodicals, Inc.

Holding tight on feathers - structural specializations and attachment properties of the avian ectoparasite Crataerina pallida (Diptera, Hippoboscidae).

Science.gov (United States)

Petersen, Dennis S; Kreuter, Nils; Heepe, Lars; Büsse, Sebastian; Wellbrock, Arndt H J; Witte, Klaudia; Gorb, Stanislav N

2018-04-30

The louse fly Crataerina pallida is an obligate blood-sucking ecto-parasite of the common swift Apus apus Due to reduction of the wings, C. pallida is unable to fly, thus an effective and reliable attachment to their host's plumage is of outmost importance. Its attachment system shows several modifications in comparison to other calyptrate flies. The most prominent ones are the large tridentate claws and the dichotomously shaped setae located on the pulvilli. Based on data from morphological analysis, confocal laser scanning microscopy, cryo-scanning electron microscopy and traction force experiments, performed on native (feathers) as well as artificial substrates (glass, epoxy-resin and silicone rubber), we showed that the entire attachment system is highly adapted to the fly's lifestyle as an ectoparasite. The claws in particular are the main contributor to strong attachment to the host. Resulting attachment forces on feathers make it impossible to detach C. pallida without damage of feathers or legs of the fly itself. Well-developed pulvilli are responsible for the attachment to smooth surfaces. Both dichotomously shaped setae and high setal density explain high safety factors observed on smooth substrates. For the first time, we demonstrated a material gradient within the setae with soft, resilin dominated apical tips and stiff, more sclerotized bases in Diptera. The empodium seems not to be directly involved in the attachment process, but it might operate as a cleaning device and may be essential to maintain the functionality of the entire attachment system. © 2018. Published by The Company of Biologists Ltd.

Electron delocalization in α-nitrogen

International Nuclear Information System (INIS)

Storchak, V.; Brewer, J.H.; Morris, G.D.; British Columbia Univ., Vancouver, BC

1995-06-01

A new technique has been developed for measuring electron drift mobility in crystals on a microscopic scale through its effect on muonium (Mu = μ + + e - ) atom formation via transport of electrons to thermalized positive muons (μ + ). Electron transport mechanisms are shown to be fundamentally different in the α and β phases of solid nitrogen, giving of about 5 orders of magnitude difference in electron mobilities. Contrary to previously reported results of macroscopic time-of-flight measurements, excess electrons appear to be delocalized in α-N 2 . (author). 22 refs., 3 figs

Chicken Juice Enhances Surface Attachment and Biofilm Formation of Campylobacter jejuni

Science.gov (United States)

Brown, Helen L.; Reuter, Mark; Salt, Louise J.; Cross, Kathryn L.; Betts, Roy P.

2014-01-01

The bacterial pathogen Campylobacter jejuni is primarily transmitted via the consumption of contaminated foodstuffs, especially poultry meat. In food processing environments, C. jejuni is required to survive a multitude of stresses and requires the use of specific survival mechanisms, such as biofilms. An initial step in biofilm formation is bacterial attachment to a surface. Here, we investigated the effects of a chicken meat exudate (chicken juice) on C. jejuni surface attachment and biofilm formation. Supplementation of brucella broth with ≥5% chicken juice resulted in increased biofilm formation on glass, polystyrene, and stainless steel surfaces with four C. jejuni isolates and one C. coli isolate in both microaerobic and aerobic conditions. When incubated with chicken juice, C. jejuni was both able to grow and form biofilms in static cultures in aerobic conditions. Electron microscopy showed that C. jejuni cells were associated with chicken juice particulates attached to the abiotic surface rather than the surface itself. This suggests that chicken juice contributes to C. jejuni biofilm formation by covering and conditioning the abiotic surface and is a source of nutrients. Chicken juice was able to complement the reduction in biofilm formation of an aflagellated mutant of C. jejuni, indicating that chicken juice may support food chain transmission of isolates with lowered motility. We provide here a useful model for studying the interaction of C. jejuni biofilms in food chain-relevant conditions and also show a possible mechanism for C. jejuni cell attachment and biofilm initiation on abiotic surfaces within the food chain. PMID:25192991

The importance of shared environment in infant-father attachment: A behavioral genetic study of the Attachment Q-Sort

NARCIS (Netherlands)

Bakermans-Kranenburg, M.J.; van IJzendoorn, M.H.; Bokhorst, C.L.; Schuengel, C.

2004-01-01

In this first behavior genetic study on infant-father attachment, we estimated genetic and environmental influences on infant-father attachment behaviors and on temperamental dependency, both assessed with the Attachment Q-Sort (AQS; B. E.Vaughn & E. Waters, 1990; E. Waters, 1995). Mothers of mono-

Molecular simulation of excess isotherm and excess enthalpy change in gas-phase adsorption.

Science.gov (United States)

Do, D D; Do, H D; Nicholson, D

2009-01-29

We present a new approach to calculating excess isotherm and differential enthalpy of adsorption on surfaces or in confined spaces by the Monte Carlo molecular simulation method. The approach is very general and, most importantly, is unambiguous in its application to any configuration of solid structure (crystalline, graphite layer or disordered porous glass), to any type of fluid (simple or complex molecule), and to any operating conditions (subcritical or supercritical). The behavior of the adsorbed phase is studied using the partial molar energy of the simulation box. However, to characterize adsorption for comparison with experimental data, the isotherm is best described by the excess amount, and the enthalpy of adsorption is defined as the change in the total enthalpy of the simulation box with the change in the excess amount, keeping the total number (gas + adsorbed phases) constant. The excess quantities (capacity and energy) require a choice of a reference gaseous phase, which is defined as the adsorptive gas phase occupying the accessible volume and having a density equal to the bulk gas density. The accessible volume is defined as the mean volume space accessible to the center of mass of the adsorbate under consideration. With this choice, the excess isotherm passes through a maximum but always remains positive. This is in stark contrast to the literature where helium void volume is used (which is always greater than the accessible volume) and the resulting excess can be negative. Our definition of enthalpy change is equivalent to the difference between the partial molar enthalpy of the gas phase and the partial molar enthalpy of the adsorbed phase. There is no need to assume ideal gas or negligible molar volume of the adsorbed phase as is traditionally done in the literature. We illustrate this new approach with adsorption of argon, nitrogen, and carbon dioxide under subcritical and supercritical conditions.

Attachment Competences in Children With ADHD During the Social-Skills Training and Attachment (SOSTRA) Randomized Clinical Trial

DEFF Research Database (Denmark)

Storebø, Ole Jakob; Skoog, Maria Annette Annelie; Darling Rasmussen, Pernille

2014-01-01

% confidence interval = [0.31, 3.58], p = .91). In total, 17 children (36%) changed their entry status, 1 (2%) from secure to insecure attachment, while 16 (34%) changed from insecure to secure attachment. Conclusion: The experimental treatment does not seem to affect attachment competences compared......Objective: To investigate the effects of social-skills training and a parental training program on children with ADHD as measured by the children's attachment competences. Method: The SOSTRA trial is a randomized, parallel-group, outcome-assessor-blinded, superiority trial evaluating 8 weeks social......-skills training and parental training plus standard treatment versus standard treatment alone for 8- to 12-year old children with ADHD. Results: There were no significant differences in attachment competences at 6 months between the experimental (n = 25) and the control (n = 22) groups (odds ratio = 1.06, 95...

The Relationship between Maternal-Fetal Attachment and Mother-Infant Attachment Behaviors in Primiparous Women Referring to Mashhad Health Care Centers

Directory of Open Access Journals (Sweden)

Mahin Taffazoli

2015-04-01

Full Text Available Background & aim: Mother-infant bonding and interactions after childbirth are shaped by maternal-fetal attachment during pregnancy. Although many studies have shown the positive correlation between maternal-fetal attachment and mother-infant attachment behaviors, some controversial studies have shown otherwise. Therefore, this study aimed to evaluate the correlation between maternal-fetal attachment and mother-infant attachment behaviors in primiparous women. Methods:This descriptive correlational study was conducted on 100 primiparous women, referring to the selected heath care centers of Mashhad. Data were collected using Cranley's maternal–fetal attachment scale, Avant’s mother-infant attachment tool, Edinburgh postnatal depression scale, and a demographic/obstetric questionnaire including demographic data, obstetric information, delivery outcomes, and postpartum data. Pregnant women with a gestational age of 35-41 weeks, who met the inclusion criteria, completed Cranley's questionnaire, as well as the demographic/obstetric questionnaire. Four and eight weeks after delivery, the subjects were asked to complete the Edinburgh questionnaire and postpartum information; then, they were asked to breastfeed their infants on a chair in a quiet place for 15 minutes. The researcher observed the mothers’ behaviors toward their neonates. For data analysis, descriptive and analytical tests were performed, using SPSS version 16. Results: There was a direct positive relationship between maternal-fetal attachment and mothers’ emotional behaviors toward infants four and eight weeks after delivery. However, four and eight weeks after childbirth, no significant correlation was found between maternal-fetal attachment and mothers’ caring behaviors. Conclusion: According to the findings, maternal-fetal attachment is one of the most important factors for mother-infant attachment. These findings could be applied for enriching mother-infant attachment

Ecomorphology of parasite attachment: experiments with feather lice.

Science.gov (United States)

Bush, Sarah E; Sohn, Edward; Clayton, Dale H

2006-02-01

The host specificity of some parasites can be reinforced by morphological specialization for attachment to mobile hosts. For example, ectoparasites with adaptations for attaching to hosts of a particular size might not be able to remain attached to larger or smaller hosts. This hypothesis is suggested by the positive correlation documented between the body sizes of many parasites and their hosts. We adopted an ecomorphological approach to test the attachment hypothesis. We tested the ability of host-specific feather lice (Phthiraptera: Ischnocera) to attach to 6 novel species of pigeons and doves that vary in size by nearly 2 orders of magnitude. Surprisingly, Rock Pigeon lice (Columbicola columbae) remained attached equally well to all 6 novel host species. We tested the relative importance of 3 factors that could facilitate louse attachment: whole-body insertion, tarsal claw use, and mandible use. Insertion, per se, was not necessary for attachment. However, insertion on coarse feathers of large hosts allowed lice to access feather barbules with their mandibles. Mandible use was a key component of attachment regardless of feather size. Attachment constraints do not appear to reinforce host specificity in this system.

Wait Up!: Attachment and Sovereign Power.

Science.gov (United States)

Duschinsky, Robbie; Greco, Monica; Solomon, Judith

2015-09-01

Sociologists and feminist scholars have, over many decades, characterised attachment as a social construction that functions to support political and gender conservatism. We accept that attachment theory has seen use to these ends and consider recent deployments of attachment theory as justification for a minimal State within conservative political discourse in the UK since 2009. However, we contest that attachment is reducible to its discursive construction. We consider Judith Butler's depiction of the infant attached to an abusive caregiver as a foundation and parallel to the position of the adult citizen subjected to punitive cultural norms and political institutions. We develop and qualify Butler's account, drawing on the insights offered by the work of Lauren Berlant. We also return to Foucault's Psychiatric Power lectures, in which familial relations are situated as an island of sovereign power within the sea of modern disciplinary institutions. These reflections help advance analysis of three important issues: the social and political implications of attachment research; the relationship between disciplinary and sovereign power in the affective dynamic of subjection; and the political and ethical status of professional activity within the psy disciplines.

Adult attachment style and anxiety

DEFF Research Database (Denmark)

Nielsen, Sara Kerstine Kaya; Lønfeldt, Nicole Nadine; Wolitzky-Taylor, Kate

2017-01-01

Although there is substantial evidence for the role of emotion regulation in the etiology and maintenance of anxiety disorders, knowledge about what contributes to emotion dysregulation is sparse. Attachment style is related to emotion regulation and anxiety symptoms, but these variables have rar...... knowledge to examine the mediating role of emotion regulation between attachment dimensions (avoidance and anxiety) and anxiety symptoms.......Although there is substantial evidence for the role of emotion regulation in the etiology and maintenance of anxiety disorders, knowledge about what contributes to emotion dysregulation is sparse. Attachment style is related to emotion regulation and anxiety symptoms, but these variables have...... rarely been examined together. Examining emotion dysregulation within the context of anxiety disorders through an attachment theory framework will lead to a better understanding of the etiology and maintenance of anxiety disorders. In the present study we combined theoretically and empirically derived...

Sine-Bar Attachment For Machine Tools

Science.gov (United States)

Mann, Franklin D.

1988-01-01

Sine-bar attachment for collets, spindles, and chucks helps machinists set up quickly for precise angular cuts that require greater precision than provided by graduations of machine tools. Machinist uses attachment to index head, carriage of milling machine or lathe relative to table or turning axis of tool. Attachment accurate to 1 minute or arc depending on length of sine bar and precision of gauge blocks in setup. Attachment installs quickly and easily on almost any type of lathe or mill. Requires no special clamps or fixtures, and eliminates many trial-and-error measurements. More stable than improvised setups and not jarred out of position readily.

Overdenture locator attachments for atrophic mandible

Directory of Open Access Journals (Sweden)

Neerja Mahajan

2013-01-01

Full Text Available Implant-supported overdentures provide a good opportunity for dentists to improve oral health and quality-of-life of patients. Atrophic mandible poses a significant challenge to successful oral rehabilitation with dental implants. In this article, the fabrication of lower overdenture by two narrow platform implants is described with dual retentive, resilient, self-locating locator attachment system. The locator attachment system has the lowest profile in comparison with the ball and bar attachments and is versatile up to 40΀ of divergence between two implants. By using locators as attachments, we can meet functional, economic and social expectation of patients with ease and satisfaction.

Associations Between Maternal-Foetal Attachment and Infant Developmental Outcomes: A Systematic Review.

Science.gov (United States)

Branjerdporn, Grace; Meredith, Pamela; Strong, Jenny; Garcia, Jenniffer

2017-03-01

Objectives Infant developmental outcomes may be influenced by a range of prenatal maternal characteristics. While there is some evidence to suggest that maternal-foetal attachment may be associated with infant developmental outcomes, there is a need to systematically review this evidence to guide future research and clinical practice. Methods Five electronic databases were systematically scanned. Key journals and reference lists were hand-searched. Papers were included if: (1) pregnant women were assessed for maternal-foetal attachment; (2) the infants were later assessed, under 2 years old, for any developmental outcome (e.g., social-emotional, cognition, motor, language, adaptive behaviour); and (3) they were published in English. Two independent reviewers used the STROBE checklist to appraise the quality of each paper. Results Of the 968 papers identified, eight were included in the review, and four of these were of low quality (infant temperament (n = 5), adaptive behaviour (e.g., colic, sleep) (n = 2), and milestone attainment (n = 1). There is some evidence to suggest that lower maternal-foetal attachment is related to suboptimal developmental outcomes. However, these results should be interpreted with caution due to the limited and low quality studies available. Conclusions Although maternal-foetal attachment may be associated with infant developmental outcomes, future research is required which: (1) considers a range of developmental outcomes, (2) has increased scientific rigour, (3) assesses mother-infant dyads at different prenatal and postnatal time points, and (4) examines different target populations.

Insecure attachment and anxiety in student athletes.

Science.gov (United States)

Han, D H; Kim, S M; Zaichkowsky, L

2013-06-01

The main purpose of our research was to examine attachment type and competition anxiety in high school student athletes and general high school students. We recruited 465 student athletes and 543 general students to participate in our study. The Revised Korean version of the Experiences in Close Relationships Scale (K-ECRS) and the Competitive State Anxiety Inventory-2 (CSAI-2) were given to all students. In χ2 tests, athletes showed attachment types in the following order of prevalence: fearful, dismissive, and preoccupied, compared to the fearful, preoccupied, and dismissive order observed in general students. In parametric, independent t-tests, athletes reported significantly higher cognitive anxiety scores, relative to general students. Further, athletes with insecure attachment compared to those with secure attachment reported higher cognitive anxiety scores and self-confidence scores. In both the athletes with insecure attachment and general students with insecure attachment groups, the K-ECRS anxiety subscale was significantly correlated with CSAI-2 total score. In post hoc analysis in the athletes with insecure attachment group, the K-ECRS anxiety subscale was also significantly correlated with the CSAI-2 cognitive anxiety subscale. These results suggest that anxious athletes with an insecure attachment style tend to exaggerate threats from both external and internal sources, which negatively affect their performances.

34 CFR 668.166 - Excess cash.

Science.gov (United States)

2010-07-01

... the Secretary for the costs the Secretary incurred in providing that excess cash to the institution... 34 Education 3 2010-07-01 2010-07-01 false Excess cash. 668.166 Section 668.166 Education..., DEPARTMENT OF EDUCATION STUDENT ASSISTANCE GENERAL PROVISIONS Cash Management § 668.166 Excess cash. (a...

Universal precision sine bar attachment

Science.gov (United States)

Mann, Franklin D. (Inventor)

1989-01-01

This invention relates to an attachment for a sine bar which can be used to perform measurements during lathe operations or other types of machining operations. The attachment can be used for setting precision angles on vises, dividing heads, rotary tables and angle plates. It can also be used in the inspection of machined parts, when close tolerances are required, and in the layout of precision hardware. The novelty of the invention is believed to reside in a specific versatile sine bar attachment for measuring a variety of angles on a number of different types of equipment.

Excess water dynamics in hydrotalcite: QENS study

Indian Academy of Sciences (India)

dynamics of excess water in hydrotalcite sample with varied content of excess water are reported. Translational motion of excess water can be best described by random transla- tional jump diffusion model. The observed increase in translational diffusivity with increase in the amount of excess water is attributed to the ...

Growing networks with mixed attachment mechanisms

International Nuclear Information System (INIS)

Shao Zhigang; Zou Xianwu; Tan Zhijie; Jin Zhunzhi

2006-01-01

Networks grow and evolve when new nodes and links are added in. There are two methods to add the links: uniform attachment and preferential attachment. We take account of the addition of links with mixed attachment between uniform attachment and preferential attachment in proportion. By using numerical simulations and analysis based on a continuum theory, we obtain that the degree distribution P(k) has an extended power-law form P(k) ∼ (k + k 0 ) -γ . When the number of edges k of a node is much larger than a certain value k 0 , the degree distribution reduces to the power-law form P(k) ∼ k -γ ; and when k is much smaller than k 0 , the degree distribution degenerates into the exponential form P(k)∼exp(-yk/k 0 ). It has been found that degree distribution possesses this extended power-law form for many real networks, such as the movie actor network, the citation network of scientific papers and diverse protein interaction networks

Laser enhanced attachment in diffuse discharges

International Nuclear Information System (INIS)

Giesselmann, M.; Pashaie, B.; Kristiansen, M.; Schaefer, G.

1987-01-01

Measurements of the effect of laser enhanced attachment on externally sustained diffuse discharges are reported. Optical control of diffuse discharges is a promising way of upgrading the performance of e-beam controlled opening switches for repetitive operation. Ideal gases should exhibit a negligible attachment cross section for low E/N values (switch closed) in the ground state and strong attaching properties upon optical excitation in an E/N range between the conducting state and self breakdown of the switch. The ratio of resistivity change in these experiments is much higher than in previous investigations. In this investigation the attachment rate of an electronegative gas component, representing approximately 1% of the gas in the discharge volume, was increased by means of vibrational excitation with a pulsed IR-laser beam. Molecules exhibiting a strongly increased attachment rate upon IR-excitation are vinyl-chloride, vinyl flouride and trifluoroethylene, which has been verified in preliminary experiments. All experiments reported were performed with vinyl chloride and trifluoroethylene

75 FR 30846 - Monthly Report of Excess Income and Annual Report of Uses of Excess Income (Correction)

Science.gov (United States)

2010-06-02

... Income and Annual Report of Uses of Excess Income (Correction) AGENCY: Office of the Chief Information.... Project owners are permitted to retain Excess Income for projects under terms and conditions established by HUD. Owners must request to retain some or all of their Excess Income. The request must be...

7 CFR 985.56 - Excess oil.

Science.gov (United States)

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Excess oil. 985.56 Section 985.56 Agriculture... HANDLING OF SPEARMINT OIL PRODUCED IN THE FAR WEST Order Regulating Handling Volume Limitations § 985.56 Excess oil. Oil of any class in excess of a producer's applicable annual allotment shall be identified as...

Implementation and assessment of an early home-based intervention on infant attachment organisation: the CAPEDP attachment study in France.

Science.gov (United States)

Tereno, Susana; Guedeney, Nicole; Dugravier, Romain; Greacen, Tim; Saïas, Thomas; Tubach, Florence; Guédeney, Antoine

2013-06-01

Attachment is a long-term emotional link between infants and their mothers. Attachment quality influences subsequent psychosocial relationships, the ability to manage stress and, consequently, later mental health. Home intervention programmes targeting infant attachment have been implemented in several contexts with varying degrees of efficacy. Within the CAPEDP study (Parental Skills and Attachment in Early Childhood: reduction of risks linked to mental health problems and promotion of resilience), a subsample of 120 families were recruited with the objective of assessing the impact of this home-visiting programme on infant attachment organisation using the Strange Situation Procedure. The present paper describes the methodology used in this ancillary study.

Attachment Theory, Foster Parents and Diversity Tolerance

OpenAIRE

Kenny, Michael; Fleming, Ted

2009-01-01

relevance to attachment within the biological and foster family. Yet every foster parent has a childhood attachment history that influences their interpersonal relationships in adulthood. The primary concern of the foster parent and their supports is with the foster child. But as a result the foster parent may distract or block reflection on their own attachment history. This presentation will focus on attachment theory and the adult, with particular reference to the foster parent. The pre...

Superego: an attachment perspective.

Science.gov (United States)

Holmes, Jeremy

2011-10-01

With the help of attachment theory and research, the paper attempts to broaden and build on classical and current views on the superego. Attachment theory's epigenetic approach and the concept of the subliminal superego are described. The superego, it is argued, is as much concerned with safety as sex. The superego is 'heir', not just to the Oedipus complex or Klein's pre-oedipal constellation, but also to the attachment relationship. Under favourable developmental conditions a 'mature superego' emerges, facilitating, in the presence of an internal secure base, maturational boundary crossings towards adult sexuality. In the light of the above, the paper reviews Lear's updating of Strachey's model of psychic change and explores the concept of transgression in relation to the 'professional superego', its development and maturation. Theoretical arguments are illustrated with clinical examples. Copyright © 2011 Institute of Psychoanalysis.

Polarized electron sources

Energy Technology Data Exchange (ETDEWEB)

Prepost, R. [Univ. of Wisconsin, Madison, WI (United States)

1994-12-01

The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented.

Polarized electron sources

International Nuclear Information System (INIS)

Prepost, R.

1994-01-01

The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented

On the excess photon noise in single-beam measurements with photo-emissive and photo-conductive cells

NARCIS (Netherlands)

Alkemade, C.T.J.

In this paper the so-called excess photon noise is theoretically considered with regard to noise power measurements with a single, illumined photo-emissive or photo-conductive cell. Starting from a modification of Mandel's stochastic association of the emission of photo-electrons with wave

Direct observation of shear–induced nanocrystal attachment and coalescence in CuZr-based metallic glasses: TEM investigation

International Nuclear Information System (INIS)

Hajlaoui, K.; Alrasheedi, Nashmi H.; Yavari, A.R.

2016-01-01

In-situ tensile straining tests were performed in a transmission electron microscope (TEM) to analyse the deformation processes in CuZr-based metallic glasses and to directly observe the phase transformation occurrence. We report evidence of shear induced coalescence of nanocrystals in the vicinity of deformed regions. Nanocrystals grow in shear bands, come into contact, being attached and progressively coalesce under applied shear stress. - Highlights: • In-situ tensile straining test in TEM was investigated on CuZr-Based metallic glass. • Strain induces nanocrystallization and subsequent attachment and coalescence of nanocrystals. • The coalescence of nanocrystals compensates strain softening in metallic glasses.

Infant-parent attachment: Definition, types, antecedents, measurement and outcome.

Science.gov (United States)

Benoit, Diane

2004-10-01

Attachment theory is one of the most popular and empirically grounded theories relating to parenting. The purpose of the present article is to review some pertinent aspects of attachment theory and findings from attachment research. Attachment is one specific aspect of the relationship between a child and a parent with its purpose being to make a child safe, secure and protected. Attachment is distinguished from other aspects of parenting, such as disciplining, entertaining and teaching. Common misconceptions about what attachment is and what it is not are discussed. The distinction between attachment and bonding is provided. The recognized method to assess infant-parent attachment, the Strange Situation procedure, is described. In addition, a description is provided for the four major types of infant-parent attachment, ie, secure, insecure-avoidant, insecure-resistant and insecure-disorganized. The antecedents and consequences of each of the four types of infant-parent attachment are discussed. A special emphasis is placed on the description of disorganized attachment because of its association with significant emotional and behavioural problems, and poor social and emotional outcomes in high-risk groups and in the majority of children who have disorganized attachment with their primary caregiver. Practical applications of attachment theory and research are presented.

Personality and Attachment in Transsexual Adults.

Science.gov (United States)

Lingiardi, Vittorio; Giovanardi, Guido; Fortunato, Alexandro; Nassisi, Valentina; Speranza, Anna Maria

2017-07-01

The main aim of this study was to investigate the associations between personality features and attachment patterns in transsexual adults. We explored mental representations of attachment, assessed personality traits, and possible personality disorders. Forty-four individuals diagnosed with gender identity disorder (now gender dysphoria), 28 male-to-female and 16 female-to-male, were evaluated using the Shedler-Westen assessment procedure-200 (SWAP-200) to assess personality traits and disorders; the adult attachment interview was used to evaluate their attachment state-of-mind. With respect to attachment, our sample differed both from normative samples because of the high percentage of disorganized states of mind (50% of the sample), and from clinical samples for the conspicuous percentage of secure states of mind (37%). Furthermore, we found that only 16% of our sample presented a personality disorder, while 50% showed a high level of functioning according to the SWAP-200 scales. In order to find latent subgroups that shared personality characteristics, we performed a Q-factor analysis. Three personality clusters then emerged: Healthy Functioning (54% of the sample); Depressive/Introverted (32%) and Histrionic/Extroverted (14%). These data indicate that in terms of personality and attachment, GD individuals are a heterogeneous sample and show articulate and diverse types with regard to these constructs.

Attachment in young children with incarcerated fathers.

Science.gov (United States)

Poehlmann-Tynan, Julie; Burnson, Cynthia; Runion, Hilary; Weymouth, Lindsay A

2017-05-01

The present study examined young children's attachment behaviors during paternal incarceration and reported on initial validity of a new measure used to rate children's attachment-related behaviors and emotions during visits in a corrections setting. Seventy-seven children, age 2 to 6 years, and their jailed fathers and current caregivers participated in the home visit portion of the study, whereas 28 of these children participated in the jail visit. The results indicated that 27% of children witnessed the father's crime and 22% of children witnessed the father's arrest, with most children who witnessed these events exhibiting extreme distress; children who witnessed these events were more likely to have insecure attachments to their caregivers. Consistent with attachment theory and research, caregivers who exhibited more sensitivity and responsivity during interactions with children and those who provided more stimulating, responsive, learning-oriented home environments had children who were more likely to have secure attachments (measured with the Attachment Q-Sort). We also found preliminary evidence for the validity of our new measure, the Jail Prison Observation Checklist, in that children's attachment-related behaviors and emotions during the jail visit correlated with their attachment security observed in the home. Our observations indicate that, in certain contexts, noncontact visits with incarcerated parents can be stressful for children and that children's caregivers may play a significant role during these visits.

Attachment, caring and prosocial behavior

NARCIS (Netherlands)

Erez, Ayelet

2007-01-01

The thesis focuses on 5 studies examining the role of adult attachment in volunteering by defining volunteerism as a form of caregiving. By that we suggest an effect of one behavioral system, attachment, on another, caring or prosocial behaviors in individual or group settings. Studies 1 and 2

Electronic ripple indicator

Science.gov (United States)

Davidson, J. K.; Houck, W. H.

1971-01-01

Electronic circuit for monitoring excessive ripple voltage on dc power lines senses voltage variations from few millivolts to maximum of 10 volts rms. Instrument is used wherever power supply fluctuations might endanger system operations or damage equipment. Device is inexpensive and easily packaged in small chassis.

10 CFR 904.10 - Excess energy.

Science.gov (United States)

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Excess energy. 904.10 Section 904.10 Energy DEPARTMENT OF ENERGY GENERAL REGULATIONS FOR THE CHARGES FOR THE SALE OF POWER FROM THE BOULDER CANYON PROJECT Power Marketing § 904.10 Excess energy. (a) If excess Energy is determined by the United States to be available...

Kinetic analysis of thymocyte attachment to thymus stromal cells in culture by using phase-contrast and scanning electron microscopy

International Nuclear Information System (INIS)

LaRochelle, G.G.; Jones, K.H.

1989-01-01

Direct cellular contact between thymocytes and thymus stromal cells within the thymus appears to contribute to the maturation of thymocytes. Thymocyte-stromal cell complexes, formed in vivo, have been isolated by others and postulated to play a role in T-cell differentiation. These previous studies have been hampered, however, by a time-consuming isolation procedure from which only small numbers of these complexes are recovered. We have examined a model to study thymocyte-stromal cell complexes in vitro in which thymocytes are added to primary cultures of thymus stromal cells. In the present study, we found that thymocytes were histotypically selective in their attachment to thymus stromal cells. We also investigated the kinetics of thymocyte attachment to these thymus stromal cells. Cultures were examined at selected time intervals from 5 min through 3 days of incubation. Thymocyte attachment to stromal cells was a biphasic interaction, with maximum surface attachment at 15 min of cocultivation, followed by migration of thymocytes into the cultures. Morphological studies were confirmed by using 3 H-leucine-labeled thymocytes and liquid scintigraphy. With increased time in culture, thymocytes became amoeboid and migrated between the layers of stromal cells where thymocyte mitotic figures were seen at 4 and 8 hr. In some cases it appeared that stromal cells, which often grew two to three cell layers deep, played an active role in enclosing thymocytes within the cultures. Large numbers of viable thymocytes were observed in the cultures at 24 hr. The number of thymocytes then decreased progressively on days 2 and 3, when relatively few were found within the layers of the culture

30 CFR 77.1437 - End attachment retermination.

Science.gov (United States)

2010-07-01

... 77.1437 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL... at an attachment; (b) Improper installation of an attachment; (c) Slippage at an attachment; or (d...

Place attachment and disasters: Knowns and unknowns.

Science.gov (United States)

Jamali, Mehdi; Nejat, Ali

When considering the factors important for disaster recovery, one must consider the attachment individuals have toward their living area. This article reviews and synthesizes the current literature on the determinants of place attachment in the context of postdisaster recovery. Although the majority of the reviewed articles focused on disaster recovery, there were some which had a broader scope and were included due to their importance. This research categorizes the determinants of place attachment into four categories: demographic, socioeconomic, spatial, and psychosocial. Age, ethnicity, and religion were grouped under the category of demographics. Job status, education, and property ownership were categorized under the socioeconomic category. Attachment to home, neighborhood, and city, together with attachment to rural and urban areas, were grouped under the spatial category. Finally, mental health status and community attachment were classified under the psychosocial heading. Based on the outcome of the aforementioned synthesis, this article develops a conceptual framework to guide future research.

Pressure-dependent electron attachment and breakdown strengths of unitary gases, and synergism of binary gas mixtures: a relationship

International Nuclear Information System (INIS)

Hunter, S.R.; Christophorou, L.G.

1984-04-01

The relationship between the pressure-dependent electron attachment rate constants (k/sub a/) which have been observed in 1-C 3 F 6 and in several perfluoroalkanes, and the uniform field breakdown strengths (E/N)/sub lim/ in these gases is discussed. Measurements of the pressure dependence of k/sub a/ of OCS in a buffer gas of Ar are presented and the possible pressure dependence of (E/N)/sub lim/ in OCS is discussed. Uniform field breakdown measurements have been performed in C 3 F 8 , n-C 4 F 10 , and SO 2 over a range of gas pressures (3 less than or equal to P/sub T/ less than or equal to 290 kPa) and are reported. All three molecules have been found to possess pressure-dependent (E/N)/sub lim/ values. The various types of synergistic behavior which have been observed in binary gas dielectric mixtures are summarized and discussed. A new mechanism is outlined which can explain the synergism observed in several gas mixtures where the (E/N)/sub lim/ values of the mixutres are greater than those of the individual gas constituents. Model calculations are presented which support this mechanism, and can be used to explain the pressure-dependent synergistic effects which have been reported in 1-C 3 F 6 /SF 6 gas mixture

Electron collisions with biomolecules

International Nuclear Information System (INIS)

McKoy, V; Winstead, C

2008-01-01

We report on results of recent studies of collisions of low-energy electrons with nucleobases and other DNA constituents. A particular focus of these studies has been the identification and characterization of resonances that play a role in electron attachment leading to strand breaks in DNA. Comparison of the calculated resonance positions with results of electron transmission measurements is quite encouraging. However, the higher-lying π* resonances of the nucleobases appear to be of mixed elastic and core-excited character. Such resonant channel coupling raises the interesting possibility that the higher π*resonances in the nucleobases may promote dissociation of DNA by providing doorway states to triplet excited states.

30 CFR 57.19028 - End attachment replacement.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false End attachment replacement. 57.19028 Section 57.19028 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Hoisting Wire Ropes § 57.19028 End attachment replacement. Wire rope attachments shall be replaced when...

30 CFR 56.19028 - End attachment replacement.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false End attachment replacement. 56.19028 Section 56.19028 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Wire Ropes § 56.19028 End attachment replacement. Wire rope attachments shall be replaced when cracked...

30 CFR 77.1438 - End attachment replacement.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false End attachment replacement. 77.1438 Section 77.1438 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND... Personnel Hoisting Wire Ropes § 77.1438 End attachment replacement. Wire rope attachments shall be replaced...

Relationships between attachment and marital satisfaction in married couples

Directory of Open Access Journals (Sweden)

Patrícia Gallerová

2016-01-01

Full Text Available Theory of attachment strongly influences exploring of close relationships in childhood and in adulthood as well. According Bowlby attachment is "lasting relationship bond characterized by need of seeking and maintaining proximity with a person in stressful situations especially (Bowbly, 2010. Hazan a Shaver (1987 applied theory of early attachment in romantic relationships of adults. Behavior of adult human in relationships is more or less predictable by style of attachment in childhood (Feeney, 1999. Brennan, Clark a Shaver (1998 created four-dimensional model of attachment which was based on Ainsworth´s theory as well. The model was formed of two dimensions - anxiety and avoidance. The authors identified four types of attachment: secure, fearful, dismissive and preoccupied style of attachment (Brennan, Clark, & Shaver, 1998. Satisfaction in romantic relationship can be explained as a degree in which is relationship for a human enojyable. Attachment influences satisfaction in relationship in terms of meeting need of proximity and safety (Mikulincer, Florian, Cowan, & Cowan, 2002. Several researches show that safe attachment is associated with higher satisfaction in marriage and on the other hand people with insecure style of attachment show lower degree of satisfaction in relationship (Alexandrov, Cowan, & Cowan, 2005; Treboux, Crowell, & Waters, 2004. At the same time style of attachment of the partner also influences individual a lot, satisfaction does not depend only on his own style of attachment but also on attachment of his partner (Farinelli, & McEwan, 2009. The study examined relations between the relationship attachment and marital satisfaction. The goal was to explain the relationship between the adult attachment and marital satisfaction of the individual and her/his husband/wife. The research examined relationship between adult attachment and marital satisfaction as well. Quantitative questionnaire survey: The battery consisted of

Love attitudes and attachment

Directory of Open Access Journals (Sweden)

María Elena Brenlla

2016-02-01

Full Text Available Love styles described by Lee are Eros (passionate love, Ludus (game-pla- ying love, Storge (friendship love, Mania (possessive, dependent love, Pragma (logical, “shopping list” love and Agape (all-giving, selfless love. Based on those types, Hendrick and Hendrick developed a 42-ítem rating questionnaire with 7 items measuring each love style (Love Attitudes Scale. Beside, inform about frequency in love relationships and attachment style. The purpose of this study was analyze the reliability and factor structure of the Love Attitudes Scale and to investigate the association between love attitudes and the attachment style. The results (N=280 participants indicate adequate internal consistency (alfa = 0,73. The items were intercorrelated and factored. The best solution extracted six factors using varimax rotation and all six factors accounted 41% of the total variance. Secure attachment was related positively to eros. 

From secure dependency to attachment: Mary Ainsworth's integration of Blatz's security theory into Bowlby's attachment theory.

Science.gov (United States)

van Rosmalen, Lenny; van der Horst, Frank C P; van der Veer, René

2016-02-01

John Bowlby is generally regarded as the founder of attachment theory, with the help of Mary Ainsworth. Through her Uganda and Baltimore studies Ainsworth provided empirical evidence for attachment theory, and she contributed the notion of the secure base and exploratory behavior, the Strange Situation Procedure and its classification system, and the notion of maternal sensitivity. On closer scrutiny, many of these contributions appear to be heavily influenced by William Blatz and his security theory. Even though Blatz's influence on Ainsworth has been generally acknowledged, this article, partly based on understudied correspondence from several personal archives, is the first to show which specific parts of attachment theory can be traced back directly to Blatz and his security theory. When Ainsworth started working with Bowlby in the 1950s, around the time he turned to evolutionary theory for an explanation of his findings, she integrated much of Blatzian security theory into Bowlby's theory in the making and used her theoretical and practical experience to enrich attachment theory. Even though Blatz is hardly mentioned nowadays, several of his ideas live on in attachment theory. (c) 2016 APA, all rights reserved).

Attachment and group psychotherapy: introduction to a special section.

Science.gov (United States)

Tasca, Giorgio A

2014-03-01

The application of attachment theory to adult psychotherapy represents a growing area of research and practice. Despite the conceptual overlap between group therapeutic factors, attachment theory, and therapeutic tasks as outlined by Bowlby (1988), there is little research on attachment functioning in group therapy. Hence, there remain substantial questions about the role of attachment theory in understanding group therapy processes and outcomes. The three studies in this special section advance the research in some of these important areas, including showing that positive changes in self-reported attachment insecurity among clients persist long after group therapy ends; attachment anxiety affects the level and rate of interpersonal learning in groups; and change in attachment to the therapy group has an impact on longer term change in individual group members' attachment. Each article also examines the impact of these attachment concepts on treatment outcomes. Numerous areas remain to be explored when it comes to the implications of attachment theory for understanding and conducting group therapy, including the conceptual and practical overlap between attachment concepts such as security and exploration with group therapeutic factors such as cohesion and interpersonal learning. The articles in this special section begin to address some of these issues related to attachment theory and its implications for group therapists. (c) 2014 APA, all rights reserved.

Attachment in Middle Childhood: Progress and Prospects

Science.gov (United States)

Bosmans, Guy; Kerns, Kathryn A.

2015-01-01

Contrary to the substantial amount of research on infant, preschool, adolescent, and adult attachment, middle childhood has long been neglected by the international attachment research community. In the past two decades, however, there has been a steep increase in research focusing on middle childhood attachment. This article provides an overview…

Adhesion and friction of the smooth attachment system of the cockroach Gromphadorhina portentosa and the influence of the application of fluid adhesives

Directory of Open Access Journals (Sweden)

Oliver Betz

2017-05-01

Full Text Available Two different measurement techniques were applied to study the attachment of the smooth foot pads of the Madagascar hissing cockroach Gromphadorhina portentosa. The attachment of the non-manipulated adhesive organs was compared with that of manipulated ones (depletion or substitution by artificial secretions. From measurements of the friction on a centrifuge, it can be concluded that on nanorough surfaces, the insect appears to benefit from employing emulsions instead of pure oils to avoid excessive friction. Measurements performed with a nanotribometer on single attachment organs showed that, in the non-manipulated euplantulae, friction was clearly increased in the push direction, whereas the arolium of the fore tarsus showed higher friction in the pull direction. The surface of the euplantulae shows an imbricate appearance, whereupon the ledges face distally, which might contribute to the observed frictional anisotropy in the push direction. Upon depletion of the tarsal adhesion-mediating secretion or its replacement by oily fluids, in several cases, the anisotropic effect of the euplantula disappeared due to the decrease of friction forces in push-direction. In the euplantulae, adhesion was one to two orders of magnitude lower than friction. Whereas the tenacity was slightly decreased with depleted secretion, it was considerably increased after artificial application of oily liquids. In terms of adhesion, it is concluded that the semi-solid consistence of the natural adhesion-mediating secretion facilitates the detachment of the tarsus during locomotion. In terms of friction, on smooth to nanorough surfaces, the insects appear to benefit from employing emulsions instead of pure oils to avoid excessive friction forces, whereas on rougher surfaces the tarsal fluid rather functions in improving surface contact by keeping the cuticle compliable and compensating surface asperities of the substratum.

Multilayer electronic component systems and methods of manufacture

Science.gov (United States)

Thompson, Dane (Inventor); Wang, Guoan (Inventor); Kingsley, Nickolas D. (Inventor); Papapolymerou, Ioannis (Inventor); Tentzeris, Emmanouil M. (Inventor); Bairavasubramanian, Ramanan (Inventor); DeJean, Gerald (Inventor); Li, RongLin (Inventor)

2010-01-01

Multilayer electronic component systems and methods of manufacture are provided. In this regard, an exemplary system comprises a first layer of liquid crystal polymer (LCP), first electronic components supported by the first layer, and a second layer of LCP. The first layer is attached to the second layer by thermal bonds. Additionally, at least a portion of the first electronic components are located between the first layer and the second layer.

36 CFR 1235.48 - What documentation must agencies transfer with electronic records?

Science.gov (United States)

2010-07-01

... documentation for the following types of electronic records: (i) E-mail messages with attachments; (ii) Scanned... agencies transfer with electronic records? 1235.48 Section 1235.48 Parks, Forests, and Public Property... agencies transfer with electronic records? (a) General. Agencies must transfer documentation adequate to...

Proteomics Analysis Reveals Abnormal Electron Transport and Excessive Oxidative Stress Cause Mitochondrial Dysfunction in Placental Tissues of Early-Onset Preeclampsia.

Science.gov (United States)

Xu, Zhongwei; Jin, Xiaohan; Cai, Wei; Zhou, Maobin; Shao, Ping; Yang, Zhen; Fu, Rong; Cao, Jin; Liu, Yan; Yu, Fang; Fan, Rong; Zhang, Yan; Zou, Shuang; Zhou, Xin; Yang, Ning; Chen, Xu; Li, Yuming

2018-04-20

Early-onset preeclampsia (EOS-PE) refers to preeclampsia that occurred before 34 gestation weeks. This study was conducted to explore the relationship between mitochondrial dysfunction and the pathogenesis of EOS-PE using proteomic strategy. To identify altering expressed mitochondrial proteins between severe EOS-PE and healthy pregnancies, enrichment of mitochondria coupled with iTRAQ-based quantitative proteomic method was performed. IHC and western blot were performed to detect the alteration of changing expression proteins, and confirmed the accuracy of proteomic results. We totally quantified 1372 proteins and screened 132 altering expressed mitochondrial proteins, including 86 down-regulated expression proteins and 46 up-regulated expression proteins (pelectron transport chain and oxidative phosphorylation. Especially, mitochondrial related molecules, PRDX2, PARK7, BNIP3, BCL2, PDHA1, SUCLG1, ACADM and NDUFV1, were involved in energy production process in the matrix and membrane of mitochondria. Our results showed that abnormal electron transport, excessive oxidative stress and mitochondrion disassembly might be the main cause of mitochondrial dysfunction, and was related to the pathogenesis of EOS-PE. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Does Excessive Pronation Cause Pain?

DEFF Research Database (Denmark)

Mølgaard, Carsten Møller; Olesen Gammelgaard, Christian; Nielsen, R. G.

Excessive pronation could be an inborn abnormality or an acquired foot disorder caused by overuse, inadequate supported shoes or inadequate foot training. When the muscles and ligaments of the foot are insufficient it can cause an excessive pronation of the foot. The current treatment consist...... of antipronation shoes or insoles, which latest was studied by Kulce DG., et al (2007). So far there have been no randomized controlled studies showing methods that the effect of this treatment has not been documented. Therefore the authors can measure the effect of treatments with insoles. Some of the excessive...

A COMPREHENSIVE CENSUS OF NEARBY INFRARED EXCESS STARS

Energy Technology Data Exchange (ETDEWEB)

Cotten, Tara H.; Song, Inseok, E-mail: tara@physast.uga.edu, E-mail: song@physast.uga.edu [Department of Physics and Astronomy, University of Georgia, Athens, GA 30602 (United States)

2016-07-01

The conclusion of the Wide-Field Infrared Survey Explorer ( WISE ) mission presents an opportune time to summarize the history of using excess emission in the infrared as a tracer of circumstellar material and exploit all available data for future missions such as the James Webb Space Telescope . We have compiled a catalog of infrared excess stars from peer-reviewed articles and perform an extensive search for new infrared excess stars by cross-correlating the Tycho-2 and all-sky WISE (AllWISE) catalogs. We define a significance of excess in four spectral type divisions and select stars showing greater than either 3 σ or 5 σ significance of excess in the mid- and far-infrared. Through procedures including spectral energy distribution fitting and various image analyses, each potential excess source was rigorously vetted to eliminate false positives. The infrared excess stars from the literature and the new stars found through the Tycho-2 and AllWISE cross-correlation produced nearly 500 “Prime” infrared excess stars, of which 74 are new sources of excess, and >1200 are “Reserved” stars, of which 950 are new sources of excess. The main catalog of infrared excess stars are nearby, bright, and either demonstrate excess in more than one passband or have infrared spectroscopy confirming the infrared excess. This study identifies stars that display a spectral energy distribution suggestive of a secondary or post-protoplanetary generation of dust, and they are ideal targets for future optical and infrared imaging observations. The final catalogs of stars summarize the past work using infrared excess to detect dust disks, and with the most extensive compilation of infrared excess stars (∼1750) to date, we investigate various relationships among stellar and disk parameters.

Attachment Figure's Regulation of Infant Brain and Behavior.

Science.gov (United States)

Sullivan, Regina M

2017-01-01

Altricial infants (i.e., requiring parental care for survival), such as humans and rats, form an attachment to their caregiver and receive the nurturing and protections needed for survival. Learning has a strong role in attachment, as is illustrated by strong attachment formed to non-biological caregivers of either sex. Here we summarize and integrate results from animal and human infant attachment research that highlights the important role of social buffering (social presence) of the stress response by the attachment figure and its effect on infant processing of threat and fear through modulation of the amygdala. Indeed, this work suggests the caregiver switches off amygdala function in rodents, although recent human research suggests a similar process in humans and nonhuman primates. This cross-species analysis helps provide insight and unique understanding of attachment and its role in the neurobiology of infant behavior within attachment.

Variability of femoral muscle attachments.

Science.gov (United States)

Duda, G N; Brand, D; Freitag, S; Lierse, W; Schneider, E

1996-09-01

Analytical and experimental models of the musculoskeletal system often assume single values rather than ranges for anatomical input parameters. The hypothesis of the present study was that anatomical variability significantly influences the results of biomechanical analyses, specifically regarding the moment arms of the various thigh muscles. Insertions and origins of muscles crossing or attaching to the femur were digitized in six specimens. Muscle volumes were measured; muscle attachment area and centroid location were computed. To demonstrate the influence of inter-individual anatomic variability on a mechanical modeling parameter, the corresponding range of muscle moment arms were calculated. Standard deviations, as a percentage of the mean, were about 70% for attachment area and 80% for muscle volume and attachment centroid location. The resulting moment arms of the m. gluteus maximus and m. rectus femoris were especially sensitive to anatomical variations (SD 65%). The results indicate that sensitivity to anatomical variations should be analyzed in any investigation simulating musculoskeletal interactions. To avoid misinterpretations, investigators should consider using several anatomical configurations rather than relying on a mean data set.

Best friend attachment versus peer attachment in the prediction of adolescent psychological adjustment.

Science.gov (United States)

Wilkinson, Ross B

2010-10-01

This study examined the utility of the newly developed Adolescent Friendship Attachment Scale (AFAS) for the prediction of adolescent psychological health and school attitude. High school students (266 males, 229 females) were recruited from private and public schools in the Australian Capital Territory with ages of participants ranging from 13 to 19 years. Self-report measures of depression, self-esteem, self-competence and school attitude were administered in addition to the AFAS and a short-form of the Inventory of Parental and Peer Attachment (IPPA). Regression analyses revealed that the AFAS Anxious and Avoidant scales added to the prediction of depression, self-esteem, self-competence, and school attitude beyond the contribution of the IPPA. It is concluded that the AFAS taps aspects of adolescent attachment relationships not assessed by the IPPA and provides a useful contribution to research and practice in the area of adolescent psycho-social adjustment.

Does excessive pronation cause pain?

DEFF Research Database (Denmark)

Olesen, C G; Nielsen, Rasmus Gottschalk N; Rathleff, Michael Skovdal

2008-01-01

Excessive pronation could be an inborn abnormality or an acquired foot disorder caused by overuse, inadequate supported shoes or inadequate foot training. When the muscles and ligaments of the foot are insufficient it can cause an excessive pronation of the foot. The current treatment consist of ...

Presolvated Electron Reactions with Methyl Acetoacetate: Electron Localization, Proton-Deuteron Exchange, and H-Atom Abstraction

Directory of Open Access Journals (Sweden)

Alex Petrovici

2014-09-01

Full Text Available Radiation-produced electrons initiate various reaction processes that are important to radiation damage to biomolecules. In this work, the site of attachment of the prehydrated electrons with methyl acetoacetate (MAA, CH3-CO-CH2-COOCH3 at 77 K and subsequent reactions of the anion radical (CH3-CO•−-CH2-COOCH3 in the 77 to ca. 170 K temperature range have been investigated in homogeneous H2O and D2O aqueous glasses by electron spin resonance (ESR spectroscopy. At 77 K, the prehydrated electron attaches to MAA forming the anion radical in which the electron is delocalized over the two carbonyl groups. This species readily protonates to produce the protonated electron adduct radical CH3-C(•OH-CH2-COOCH3. The ESR spectrum of CH3-C(•OH-CH2-COOCH3 in H2O shows line components due to proton hyperfine couplings of the methyl and methylene groups. Whereas, the ESR spectrum of CH3-C(•OH-CH2-COOCH3 in D2O glass shows only the line components due to proton hyperfine couplings of CH3 group. This is expected since the methylene protons in MAA are readily exchangeable in D2O. On stepwise annealing to higher temperatures (ca. 150 to 170 K, CH3-C(•OH-CH2-COOCH3 undergoes bimolecular H-atom abstraction from MAA to form the more stable radical, CH3-CO-CH•-COOCH3. Theoretical calculations using density functional theory (DFT support the radical assignments.

Presolvated electron reactions with methyl acetoacetate: electron localization, proton-deuteron exchange, and H-atom abstraction.

Science.gov (United States)

Petrovici, Alex; Adhikary, Amitava; Kumar, Anil; Sevilla, Michael D

2014-09-01

Radiation-produced electrons initiate various reaction processes that are important to radiation damage to biomolecules. In this work, the site of attachment of the prehydrated electrons with methyl acetoacetate (MAA, CH3-CO-CH2-COOCH3) at 77 K and subsequent reactions of the anion radical (CH3-CO•--CH2-COOCH3) in the 77 to ca. 170 K temperature range have been investigated in homogeneous H2O and D2O aqueous glasses by electron spin resonance (ESR) spectroscopy. At 77 K, the prehydrated electron attaches to MAA forming the anion radical in which the electron is delocalized over the two carbonyl groups. This species readily protonates to produce the protonated electron adduct radical CH3-C(•)OH-CH2-COOCH3. The ESR spectrum of CH3-C(•)OH-CH2-COOCH3 in H2O shows line components due to proton hyperfine couplings of the methyl and methylene groups. Whereas, the ESR spectrum of CH3-C(•)OH-CH2-COOCH3 in D2O glass shows only the line components due to proton hyperfine couplings of CH3 group. This is expected since the methylene protons in MAA are readily exchangeable in D2O. On stepwise annealing to higher temperatures (ca. 150 to 170 K), CH3-C(•)OH-CH2-COOCH3 undergoes bimolecular H-atom abstraction from MAA to form the more stable radical, CH3-CO-CH•-COOCH3. Theoretical calculations using density functional theory (DFT) support the radical assignments.

Attachment and eating disorders: a research update.

Science.gov (United States)

Tasca, Giorgio A

2018-03-16

Prominent models of eating disorders tend to focus on cognitive and behavioral features, but tend not to consider important developmental issues related to affect regulation, interpersonal style, self concept, and mentalization-all of which are well conceptualized within attachment theory. Higher levels of attachment insecurity across diagnoses are related to greater eating disorder symptoms. Low parental care and early trauma may lead to attachment insecurity that then might lead to greater eating disorder symptoms. The association between insecure attachment and eating disorder severity is likely mediated by affect dysregulation and perfectionism. Recent research using the Adult Attachment Interview highlights the importance of reflective functioning in predicting treatment response and therapeutic processes, and on the utility of therapies that increase mentalization. Copyright © 2018 Elsevier Ltd. All rights reserved.

Mycoplasma genitalium attaches to human spermatozoa

DEFF Research Database (Denmark)

Svenstrup, Helle Friis; Fedder, Jens; Abraham-Peskir, Joanna

2003-01-01

BACKGROUND: Mycoplasma genitalium causes urogenital diseases in men and women and is presumed to be sexually transmitted. We wanted to investigate whether spermatozoa could serve as vectors for M.genitalium in order to cause upper genital diseases in women. METHODS: By use of Nomarski light...... microscopy and transmission X-ray microscopy, the attachment of M.genitalium to spermatozoa was studied. Semen was incubated in vitro with M.genitalium. Purified, motile spermatozoa were examined for attachment of M.genitalium by immunofluorescence microscopy. RESULTS: Mycoplasma genitalium was shown...... to adhere to the head, midpiece and tail of the spermatozoa. The spermatozoa became immotile when many M.genitalium were attached. However, the motile spermatozoa were demonstrated to carry M.genitalium and in this case the mycoplasmas were seen to attach mostly to the midpiece or neck region. Occasionally...

Preferential attachment in evolutionary earthquake networks

Science.gov (United States)

Rezaei, Soghra; Moghaddasi, Hanieh; Darooneh, Amir Hossein

2018-04-01

Earthquakes as spatio-temporal complex systems have been recently studied using complex network theory. Seismic networks are dynamical networks due to addition of new seismic events over time leading to establishing new nodes and links to the network. Here we have constructed Iran and Italy seismic networks based on Hybrid Model and testified the preferential attachment hypothesis for the connection of new nodes which states that it is more probable for newly added nodes to join the highly connected nodes comparing to the less connected ones. We showed that the preferential attachment is present in the case of earthquakes network and the attachment rate has a linear relationship with node degree. We have also found the seismic passive points, the most probable points to be influenced by other seismic places, using their preferential attachment values.

Child-Parent Attachment Styles and Borderline Personality Disorder Relationship

Directory of Open Access Journals (Sweden)

Senija Tahirovic

2016-08-01

Full Text Available Many studies have focused on the attachment styles and their impact on human functioning and relationships (Bretherton, 1992. Some attachment styles have been associated with pathological way of human overall functioning, and it has already been observed that insecure attachment style in childhood may be associated with personality dysfunction (Brennan & Shaver, 1998. The purpose of this study is to investigate how people diagnosed with borderline personality disorder (BPD describe their attachment style to the primary caregivers from their memories from childhood. This study was conducted in Germany in an inpatient psychiatric clinic. Fifteen participants represented a convenience sample, of patients already diagnosed with BPD. For this study Adult Attachment Interview (AAI was used. The AAI is a semi-structured interview focusing on the early attachment experiences and their effects based on Attachment Theory.The results indicated that people diagnosed with BPD showed both preoccupied and dismissing child-parent attachment style,however it was the dismissing attachment style that dominated in our sample. The findings supported the hypothesis that participants who showed dismissing attachment style also used positive adjectives to describe the relationship  with their primary caregiver, and those with the preoccupied attachment style used negative adjectives to describe the relationship  with their primary caregiver. Even though, study was conducted with small number of participants, the study did provide evidence that there is a relationship between BPD and attachment styles in childhood. Threfore, the study offered contribution to the already existing knowledge and research findings regarding the influence of attachment style on BPD development. Keywords: Attachment, Personality disorder, Borderline Personality Disorder (BPD, child, childhood

Combined copper/zinc attachment to prion protein

Science.gov (United States)

Hodak, Miroslav; Bernholc, Jerry

2013-03-01

Misfolding of prion protein (PrP) is responsible for diseases such as ``mad-cow disease'' in cattle and Creutzfeldt-Jacob in humans. Extensive experimental investigation has established that this protein strongly interacts with copper ions, and this ability has been linked to its still unknown function. Attachment of other metal ions (zinc, iron, manganese) have been demonstrated as well, but none of them could outcompete copper. Recent finding, however, indicates that at intermediate concentrations both copper and zinc ions can attach to the PrP at the octarepeat region, which contains high affinity metal binding sites. Based on this evidence, we have performed density functional theory simulations to investigate the combined Cu/Zn attachment. We consider all previously reported binding modes of copper at the octarepeat region and examine a possibility simultaneous Cu/Zn attachment. We find that this can indeed occur for only one of the known binding sites, when copper changes its coordination mode to allow for attachment of zinc ion. The implications of the simultaneous attachment on neural function remain to be explored.

Attachment-Focused Psychotherapy and the Wounded Self.

Science.gov (United States)

Spiegel, Eric B

2016-07-01

The concept of the "wounded self" (Wolfe, 2005) offers an integrative theoretical framework for self-wounds and their developmental origins. Alladin (2013, 2014, 2016) integrated hypnotherapy into this model to comprehensively address the unconscious protective mechanisms and maladaptive conscious cognitive strategies of the wounded self. The purpose of this article is to propose how an attachment-focused psychotherapy could be utilized in working with the wounded self. With its emphasis on developmental maturation through the frame of the attachment relationship, attachment theory is well-positioned to offer conceptual and treatment insights in treating the wounded self. E. B. Spiegel's (2016) attunement, representation, and mentalization approach to attachment-focused psychotherapy described how hypnosis can be utilized across attachment processes of attunement, representation, and mentalization toward structural maturation and developmental repair of patients with histories of complex relational trauma. In this article, the attunement, representation, and mentalization attachment approach and associated interventions are further explicated in the treatment of self-wounds in the borderline and narcissistic spectrums of personality organization. These principles of conceptualization and treatment interventions are then applied in a case example.

Analysis of electron interactions in dielectric gases

International Nuclear Information System (INIS)

Olivet, Aurelio; Duque, Daniel; Vega, Lourdes F.

2007-01-01

We present and discuss results concerning electron interactions processes of dielectric gases and their relationship with the macroscopic behavior of these gases, in particular, with their dielectric strength. Such analysis is based on calculating energies of reactions for molecular ionization, dissociative ionization, parent negative ion formation, and dissociative electron attachment processes. We hypothesize that the estimation of the required energy for a reduced number of processes that take place in electrically stressed gases could be related to the gas' capability to manage the electron flow during an electrical discharge. All calculations were done with semiempirical quantum chemistry methods, including an initial optimization of molecular geometry and heat of formation of the dielectric gases and all of species that appear during electron interaction reactions. The performance of semiempirical methods Austin model 1 and Parametric model 3 (PM3) was compared for several compounds, PM3 being superior in most cases. Calculations performed for a sample of nine dielectric gases show that electron attachment and detachment processes occur in different energy bands that do not overlap for any value of the dielectric strength. We have also analyzed the relationship between dielectric strength and two physical properties: electron affinity and ionization energy. Calculations performed for 43 dielectric gases show no clear correlation between them, although certain guidelines for the qualitative estimation of dielectric strength can still be assessed

Scalar dark matter, type II seesaw and the DAMPE cosmic ray e+ + e- excess

Science.gov (United States)

Li, Tong; Okada, Nobuchika; Shafi, Qaisar

2018-04-01

The DArk Matter Particle Explorer (DAMPE) has reported a measurement of the flux of high energy cosmic ray electrons plus positrons (CREs) in the energy range between 25GeV and 4.6TeV. With unprecedented high energy resolution, the DAMPE data exhibit an excess of the CREs flux at an energy of around 1.4TeV. In this letter, we discuss how the observed excess can be understood in a minimal framework where the Standard Model (SM) is supplemented by a stable SM singlet scalar as dark matter (DM) and type II seesaw for generating the neutrino mass matrix. In our framework, a pair of DM particles annihilates into a pair of the SM SU(2) triplet scalars (Δs) in type II seesaw, and the subsequent Δ decays create the primary source of the excessive CREs around 1.4TeV. The lepton flavor structure of the primary source of CREs has a direct relation with the neutrino oscillation data. We find that the DM interpretation of the DAMPE excess determines the pattern of neutrino mass spectrum to be the inverted hierarchy type, taking into account the constraints from the Fermi-LAT observations of dwarf spheroidal galaxies.

Effect of Attachment Type on Implant Strain in Maxillary Implant Overdentures: Comparison of Ball, Locator, and Magnet Attachments. Part 1. Overdenture with Palate.

Science.gov (United States)

Takahashi, Toshihito; Gonda, Tomoya; Maeda, Yoshinobu

Implant overdentures with attachments have been used in clinical practice and the effect of attachments on implant strain has been frequently reported. However, most studies have focused on mandibular overdentures; there are few reports on maxillary overdentures. The purpose of this study was to examine the influence of attachment type on implant strain in maxillary overdentures under various implant configurations. A maxillary edentulous model with implants and experimental overdentures were fabricated. Four strain gauges were attached to each implant, positioned in anterior, premolar, and molar areas. Three types of unsplinted attachments-ball, locator, and magnet-were set on the implants under various implant configurations. A vertical occlusal load of 98 N was applied through the mandibular complete denture, and implant strain was compared using the Kruskal-Wallis test. Ball attachments caused the greatest amount of strain, while magnet attachments caused the least amount under all conditions. For all attachments, two anterior implants caused significantly more strain than four implants (P magnet attachments are recommended to reduce implant stress. Using only two implants, especially two anterior implants, is not recommended regardless of attachment type.

Relationship between attachment styles and happiness in medical students.

Science.gov (United States)

Moghadam, Marzyeh; Rezaei, Farzin; Ghaderi, Ebrahim; Rostamian, Negar