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Sample records for double dissociation study

  1. Correlations in the hadronic double diffractive dissociation

    International Nuclear Information System (INIS)

    Goldegol, Alexandre.

    1991-05-01

    A given reaction of double diffractive dissociation is studied based on the three-component Deck Model. The correlations among the diffractive slope, the effective mass of the dissociated particle sub-system and the dissociation angle in the Gottfried-Jackson are studied based in this model. 9 refs, 19 figs

  2. Double dissociation between rules and memory in music: an event-related potential study.

    Science.gov (United States)

    Miranda, Robbin A; Ullman, Michael T

    2007-11-01

    Language and music share a number of characteristics. Crucially, both domains depend on both rules and memorized representations. Double dissociations between the neurocognition of rule-governed and memory-based knowledge have been found in language but not music. Here, the neural bases of both of these aspects of music were examined with an event-related potential (ERP) study of note violations in melodies. Rule-only violations consisted of out-of-key deviant notes that violated tonal harmony rules in novel (unfamiliar) melodies. Memory-only violations consisted of in-key deviant notes in familiar well-known melodies; these notes followed musical rules but deviated from the actual melodies. Finally, out-of-key notes in familiar well-known melodies constituted violations of both rules and memory. All three conditions were presented, within-subjects, to healthy young adults, half musicians and half non-musicians. The results revealed a double dissociation, independent of musical training, between rules and memory: both rule violation conditions, but not the memory-only violations, elicited an early, somewhat right-lateralized anterior-central negativity (ERAN), consistent with previous studies of rule violations in music, and analogous to the early left-lateralized anterior negativities elicited by rule violations in language. In contrast, both memory violation conditions, but not the rule-only violation, elicited a posterior negativity that might be characterized as an N400, an ERP component that depends, at least in part, on the processing of representations stored in long-term memory, both in language and in other domains. The results suggest that the neurocognitive rule/memory dissociation extends from language to music, further strengthening the similarities between the two domains.

  3. The role of double dissociation studies in the search for candidate endophenotypes for the comorbidity of attention deficit hyperactivity disorder and reading disability.

    NARCIS (Netherlands)

    de Jong, C.G.W.; Oosterlaan, J.; Sergeant, J.A.

    2006-01-01

    The neuropsychological underpinnings of Attention Deficit Hyperactivity Disorder (ADHD) and Reading Disability (RD) and their comorbidity may be studied usefully with the double dissociation design. The results of studies using the double dissociation method may be linked to the search for an

  4. Double dissociation between syntactic gender and picture naming processing: a brain stimulation mapping study.

    Science.gov (United States)

    Vidorreta, Jose Garbizu; Garcia, Roser; Moritz-Gasser, Sylvie; Duffau, Hugues

    2011-03-01

    Neural foundations of syntactic gender processing remain poorly understood. We used electrostimulation mapping in nine right-handed awake patients during surgery for a glioma within the left hemisphere, to study whether the cortico-subcortical structures involved in naming versus syntactic gender processing are common or distinct. In French, the article determines the grammatical gender. Thus, the patient was asked to perform a picture naming task and to give the appropriate article for each picture, with and without stimulation. Cortical stimulation elicited reproducible syntactic gender disturbances in six patients, in the inferior frontal gyrus (three cases), and in the posterior middle temporal gyrus (three cases). Interestingly, no naming disorders were generated during stimulation of the syntactic sites, while cortical areas inducing naming disturbances never elicited grammatical gender errors when stimulated. Moreover, at the subcortical level, stimulation of the white matter lateral to the caudate nucleus induced gender errors in three patients, with no naming disorders. Using cortico-subcortical electrical mapping in awake patients, we demonstrate for the first time (1) a double dissociation between syntactic gender and naming processing, supporting independent network model rather than serial theory, (2) the involvement of the left inferior frontal gyrus, especially the pars triangularis, and the posterior left middle temporal gyrus in grammatical gender processing, (3) the existence of white matter pathways, likely a sub-part of the left superior longitudinal fasciculus, underlying a large-scale distributed cortico-subcortical circuit which might selectively sub-serve syntactic gender processing, even if interconnected with parallel sub-networks involved in naming (semantic and phonological) processing. Copyright © 2010 Wiley-Liss, Inc.

  5. Correlations in the hadronic double diffractive dissociation; Correlacoes na dupla dissociacao difrativa hadronica

    Energy Technology Data Exchange (ETDEWEB)

    Goldegol, Alexandre

    1991-05-01

    A given reaction of double diffractive dissociation is studied based on the three-component Deck Model. The correlations among the diffractive slope, the effective mass of the dissociated particle sub-system and the dissociation angle in the Gottfried-Jackson are studied based in this model. 9 refs, 19 figs.

  6. A double dissociation between somatosensory processing for perception and action

    NARCIS (Netherlands)

    Anema, H.A.; van Zandvoort, M.J.E.; de Haan, E.H.F.; Kappelle, L.J.; de Kort, P.L.M.; Jansen, B.P.W.; Dijkerman, H.C.

    2009-01-01

    Human neuropsychology suggests that there are two distinct body representations. Body image and body schema are, respectively, thought to be involved in conscious perceptual judgments and unconscious sensorimotor guidance. The evidence is based on the double dissociation between disorders of

  7. A double dissociation between somatosensory processing for perception and action

    NARCIS (Netherlands)

    Anema, Helen A.; van Zandvoort, Martine J. E.; de Haan, Edward H. F.; Kappelle, L. Jaap; de Kort, Paul. L. M.; Jansen, Ben P. W.; Dijkerman, H. Chris

    Human neuropsychology suggests that there are two distinct body representations. Body image and body schema are, respectively, thought to be involved in conscious perceptual judgments and unconscious sensorimotor guidance. The evidence is based on the double dissociation between disorders of

  8. Double-dissociation between the mechanism leading to impulsivity and inattention in Attention Deficit Hyperactivity Disorder: A resting-state functional connectivity study.

    Science.gov (United States)

    Sanefuji, Masafumi; Craig, Michael; Parlatini, Valeria; Mehta, Mitul A; Murphy, Declan G; Catani, Marco; Cerliani, Leonardo; Thiebaut de Schotten, Michel

    2017-01-01

    Two core symptoms characterize Attention Deficit Hyperactivity Disorder (ADHD) subtypes: inattentiveness and hyperactivity-impulsivity. While previous brain imaging research investigated ADHD as if it was a homogenous condition, its two core symptoms may originate from different brain mechanisms. We, therefore, hypothesized that the functional connectivity of cortico-striatal and attentional networks would be different between ADHD subtypes. We studied 165 children (mean age 10.93 years; age range, 7-17 year old) diagnosed as having ADHD based on their revised Conner's rating scale score and 170 typical developing individuals (mean age 11.46 years; age range, 7-17 year old) using resting state functional fMRI. Groups were matched for age, IQ and head motion during the MRI acquisition. We fractionated the ADHD group into predominantly inattentive, hyperactive-impulsive and combined subtypes based on their revised Conner's rating scale score. We then analyzed differences in resting state functional connectivity of the cortico-striatal and attentional networks between these subtypes. We found a double dissociation of functional connectivity in the cortico-striatal and ventral attentional networks, reflecting the subtypes of the ADHD participants. Particularly, the hyperactive-impulsive subtype was associated with increased connectivity in cortico-striatal network, whereas the inattentive subtype was associated with increased connectivity in the right ventral attention network. Our study demonstrated for the first time a right lateralized, double dissociation between specific networks associated with hyperactivity-impulsivity and inattentiveness in ADHD children, providing a biological basis for exploring symptom dimensions and revealing potential targets for more personalized treatments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. AIP Single and double diffraction dissociation at the LHC

    CERN Document Server

    Fiore, Roberto; Mieskolainen, Mikael; Orava, Risto

    2017-01-01

    Single and double di ff raction dissociation at the LHC is studied in a factorizable Regge-pole model, dominated by a Pomeron pole exchange in the t channel. While the contribution from secondary reggeon exchanges at the LHC is negligible, they are indispensable to match the lower-energy, ISR and FNAL data. To this end we append to the leading Pomeron exchange an e ff ective reggeon. The main emphasis in our study is on the nucleon resonances in missing masses, that are accounted for by a dual model of the inelastic pP → M X vertex, similar to the DIS structure function, known from HERA, with a non-linear nucleon, N ∗ trajectory in the direct, M 2 X channel. Regge factorization and its breakdown due to a renormalization factor, tempering the energy rise is discussed.

  10. Double dissociation between first- and second-order processing.

    Science.gov (United States)

    Allard, Rémy; Faubert, Jocelyn

    2007-04-01

    To study the difference of sensitivity to luminance- (LM) and contrast-modulated (CM) stimuli, we compared LM and CM detection thresholds in LM- and CM-noise conditions. The results showed a double dissociation (no or little inter-attribute interaction) between the processing of these stimuli, which implies that both stimuli must be processed, at least at some point, by separate mechanisms and that both stimuli are not merged after a rectification process. A second experiment showed that the internal equivalent noise limiting the CM sensitivity was greater than the one limiting the carrier sensitivity, which suggests that the internal noise occurring before the rectification process is not limiting the CM sensitivity. These results support the hypothesis that a suboptimal rectification process partially explains the difference of LM and CM sensitivity.

  11. The Precursors of Double Dissociation between Reading and Spelling in a Transparent Orthography

    Science.gov (United States)

    Torppa, Minna; Georgiou, George K.; Niemi, Pekka; Lerkkanen, Marja-Kristiina; Poikkeus, Anna-Maija

    2017-01-01

    Research and clinical practitioners have mixed views whether reading and spelling difficulties should be combined or seen as separate. This study examined the following: (a) if double dissociation between reading and spelling can be identified in a transparent orthography (Finnish) and (b) the cognitive and noncognitive precursors of this…

  12. On the determination of double diffraction dissociation cross section at HERA

    International Nuclear Information System (INIS)

    Holtmann, H.; Nikolaev, N.N.; Speth, J.; Zakharov, B.G.

    1996-01-01

    The excitation of the proton into undetected multiparticle states (double diffraction dissociation) is an important background to single diffractive deep-inelastic processes ep→e'p'ρ 0 , e'p'J/Ψ, e'p'X at HERA. We present estimates of the admixture of the double diffraction dissociation events in all diffractive events. We find that in the J/Ψ photoproduction, electroproduction of the ρ 0 at large Q 2 and diffraction dissociation of real and virtual photons into high mass states X the contamination of the double diffraction dissociation can be as large as ∼30%, thus affecting substantially the experimental tests of the pomeron exchange in deep inelastic scattering at HERA. We discuss a possibility of tagging the double diffraction dissociation by neutrons observed in the forward neutron calorimeter. We present evaluations of the spectra of neutrons and efficiency of neutron tagging based on the experimental data for diffractive processes in the proton-proton collisions. (orig.)

  13. Low missing mass, single- and double diffraction dissociation at the LHC

    CERN Document Server

    Jenkovszky, Laszlo; Orava, Risto; Salii, Andrii

    2014-01-01

    Low missing mass, single- and double diffraction dissociation is calculated for the LHC energies from a dual-Regge model, dominated by a Pomeron Regge pole exchange. The model reproduces the rich resonance structure in the low missing mass Mx region. The diffractionly excited states lie on the nucleon trajectory, appended by the isolated Roper resonance. Detailed predictions for the squared momentum transfer and missing mass dependence of the differential and integrated single- and double diffraction dissociation in the kinematical range of present and future LHC measurements are given. The model predicts a possible turn-down of the cross section towards, t -> 0 in a region probably accessible in future experiments in the nearly forward direction. The present work is a continuation and extension (e.g. with double diffraction) of a previous work using the dual Regge approach.

  14. Dissociative Part-Dependent Resting-State Activity in Dissociative Identity Disorder : A Controlled fMRI Perfusion Study

    NARCIS (Netherlands)

    Schlumpf, Yolanda R.; Reinders, Antje A. T. S.; Nijenhuis, Ellert R. S.; Luechinger, Roger; van Osch, Matthias J. P.; Jaencke, Lutz

    2014-01-01

    Background: In accordance with the Theory of Structural Dissociation of the Personality (TSDP), studies of dissociative identity disorder (DID) have documented that two prototypical dissociative subsystems of the personality, the "Emotional Part'' (EP) and the "Apparently Normal Part'' (ANP), have

  15. Dissociation in Psychiatric Disorders: A Meta-Analysis of Studies Using the Dissociative Experiences Scale.

    Science.gov (United States)

    Lyssenko, Lisa; Schmahl, Christian; Bockhacker, Laura; Vonderlin, Ruben; Bohus, Martin; Kleindienst, Nikolaus

    2018-01-01

    Dissociation is a complex, ubiquitous construct in psychopathology. Symptoms of dissociation are present in a variety of mental disorders and have been connected to higher burden of illness and poorer treatment response, and not only in disorders with high levels of dissociation. This meta-analysis offers a systematic and evidence-based study of the prevalence and distribution of dissociation, as assessed by the Dissociative Experiences Scale, within different categories of mental disorders, and it updates an earlier meta-analysis. More than 1,900 original publications were screened, and 216 were included in the meta-analysis, comprising 15,219 individuals in 19 diagnostic categories. The largest mean dissociation scores were found in dissociative disorders (mean scores >35), followed by posttraumatic stress disorder, borderline personality disorder, and conversion disorder (mean scores >25). Somatic symptom disorder, substance-related and addictive disorders, feeding and eating disorders, schizophrenia, anxiety disorder, OCD, and most affective disorders also showed mean dissociation scores >15. Bipolar disorders yielded the lowest dissociation scores (mean score, 14.8). The findings underline the importance of careful psychopathological assessment of dissociative symptoms in the entire range of mental disorders.

  16. No double-dissociation between optic ataxia and visual agnosia: Multiple sub-streams for multiple visuo-manual integrations

    NARCIS (Netherlands)

    Pisella, L.; Binkofski, F.; Lasek, K.; Toni, I.; Rossetti, Y.

    2006-01-01

    The current dominant view of the visual system is marked by the functional and anatomical dissociation between a ventral stream specialised for perception and a dorsal stream specialised for action. The "double-dissociation" between visual agnosia (VA), a deficit of visual recognition, and optic

  17. Systematics of 2-body diffractive dissociations and search of double diffractive dissociation in K-p interactions at 14.3 GeV/c

    International Nuclear Information System (INIS)

    Pons, Yvette.

    1977-12-01

    The diffractive dissociation mechanism is shown to be general when looking at 22 mesonic or baryonic threshold enhancements. The dissociation systems are all produced peripherally and present the property of slope-mass correlation. The production slopes and cross-sections mainly depend on the diffractive excitation mass. The comparison of the results with those from the I.S.R. shows that dissociation systems are very similar in their effective mass shape, momentum transfer structure and angular distributions at center-of-mass energies differing by a factor of ten. Evidence for double diffractive dissociation mechanism is found in 2 exclusive reactions at a cross section level of 5-10+-2 μb. The factorisation hypothesis seems well verified [fr

  18. Angular correlation of the N+ ions produced in the dissociative double ionization of nitrogen

    International Nuclear Information System (INIS)

    Ezell, R.L.; Edwards, A.K.; Wood, R.M.

    1984-01-01

    The double ionization of N 2 by He + projectiles was studied by measuring the angular correlation between the two N + ions emitted in the dissociation of N 2+ 2 molecular ions. If there were no recoil velocity imposed on the N 2+ 2 ion in the initial ionizing collision, and thermal effects were neglected, the pair of N + ions would have equal and opposite velocity vectors in the laboratory frame of reference. Measuring the coincidence yield of pairs of N + ions as a function of the angle between their velocity vectors permits an estimate to be made of the component of momentum transferred to the N 2+ 2 parent ions in the beam direction. The results presented in this report show the recoil velocity to be considerably less than the mean thermal velocity of N 2 molecules at room temperature. We also report mesurements of the relative cross section for N + production from N 2+ 2 as a function of the orientation of the N 2 target molecules relative to the projectile beam axis

  19. 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

  20. Dissociated dislocations in Ni: a computational study

    International Nuclear Information System (INIS)

    Szelestey, P.; Patriarca, M.; Kaski, K.

    2005-01-01

    A systematic computational study of the behavior of a (1/2) dissociated screw dislocation in fcc nickel is presented, in which atomic interactions are described through an embedded-atom potential. A suitable external stress is applied on the system, both for modifying the equilibrium separation distance d and moving the dislocation complex. The structure of the dislocation and its corresponding changes during the motion are studied in the framework of the two-dimensional Peierls model, for different values of the ratio d/a', where a' is the period of the Peierls potential. The distance between the edge and screw components of the partials, as well as their widths, undergo a modulation with period a', as the dislocation moves, and the amplitudes of such oscillations are shown to depend on d/a'. The stress profile acting on the dislocation complex is analyzed and the effective Peierls stress is estimated for different values of d/a'

  1. 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.

  2. Childhood Traumatic Experiences, Dissociative Symptoms, and Dissociative Disorder Comorbidity Among Patients With Panic Disorder: A Preliminary Study.

    Science.gov (United States)

    Ural, Cenk; Belli, Hasan; Akbudak, Mahir; Tabo, Abdulkadir

    2015-01-01

    This study assessed childhood trauma history, dissociative symptoms, and dissociative disorder comorbidity in patients with panic disorder (PD). A total of 92 psychotropic drug-naive patients with PD, recruited from outpatient clinics in the psychiatry department of a Turkish hospital, were involved in the study. Participants were assessed using the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D), Dissociation Questionnaire, Panic and Agoraphobia Scale, Panic Disorder Severity Scale, and Childhood Trauma Questionnaire. Of the patients with PD, 18 (19%) had a comorbid dissociative disorder diagnosis on screening with the SCID-D. The most prevalent disorders were dissociative disorder not otherwise specified, dissociative amnesia, and depersonalization disorders. Patients with a high degree of dissociation symptoms and dissociative disorder comorbidity had more severe PD than those without (p dissociation and PD. Among all of the subscales, the strongest relationship was with childhood emotional abuse. Logistic regression analysis showed that emotional abuse and severity of PD were independently associated with dissociative disorder. In our study, a significant proportion of the patients with PD had concurrent diagnoses of dissociative disorder. We conclude that the predominance of PD symptoms at admission should not lead the clinician to overlook the underlying dissociative process and associated traumatic experiences among these patients.

  3. Studies of neutron dissociation at Fermilab energies

    International Nuclear Information System (INIS)

    Ferbel, T.

    1975-01-01

    The latest results obtained in a continuing investigation of neutron dissociation in (pπ - ) systems in neutron--nucleus collisions between 50 and 300 GeV/c are summarized. The nuclear coherent dissociation data are discussed first; then new measurements of total cross sections of neutrons on nuclei in the Fermilab momentum range are presented; finally, neutron dissociation using a hydrogen target is considered, and the hydrogen data are compared with expectations from simple Deck models. A substantial correlation was observed between the mass and the t of the system produced. The spin structure of the pπ - amplitudes at low mass was described surprisingly well by the simple Deck mechanism. The t-channel helicity amplitudes contained comparable contributions from flip and nonflip terms, and the states produced were not restricted to those expected on the basis of the Morrison rule. (19 figures, 2 tables) (U.S.)

  4. Detecting gradual visual changes in colour and brightness agnosia: a double dissociation.

    Science.gov (United States)

    Nijboer, Tanja C W; te Pas, Susan F; van der Smagt, Maarten J

    2011-03-09

    Two patients, one with colour agnosia and one with brightness agnosia, performed a task that required the detection of gradual temporal changes in colour and brightness. The results for these patients, who showed anaverage or an above-average performance on several tasks designed to test low-level colour and luminance (contrast) perception in the spatial domain, yielded a double dissociation; the brightness agnosic patient was within the normal range for the coloured stimuli, but much slower to detect brightness differences, whereas the colour agnosic patient was within the normal range for the achromatic stimuli, but much slower for the coloured stimuli. These results suggest that a modality-specific impairment in the detection of gradual temporal changes might be related to, if not underlie, the phenomenon of visual agnosia.

  5. Coulomb dissociation studies for astrophysical thermonuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Motobayashi, T [Dept. of Physics, Rikkyo Univ., Toshima, Tokyo (Japan)

    1998-06-01

    The Coulomb dissociation method was applied to several radiative capture processes of astrophysical interest. The method has an advantage of high experimental efficiency, which allow measurements with radioactive nuclear beams. The reactions {sup 13}N(p,{gamma}){sup 14}O and {sup 7}Be(p,{gamma}){sup 8}B are mainly discussed. They are the key reaction in the hot CNO cycle in massive stars and the one closely related to the solar neutrino problem, respectively. (orig.)

  6. Attention as a characteristic of nonclinical dissociation: an event-related potential study

    NARCIS (Netherlands)

    de Ruiter, Michiel B.; Phaf, R. Hans; Veltman, Dick J.; Kok, Albert; van Dyck, Richard

    2003-01-01

    Individual differences in dissociative style (which is generally considered a risk factor for dissociative pathology) were studied in a nonclinical sample. It was hypothesized that high-dissociative participants would show enhanced attentional abilities toward both relevant and irrelevant stimulus

  7. Dissociative Part-Dependent Resting-State Activity in Dissociative Identity Disorder: A Controlled fMRI Perfusion Study

    OpenAIRE

    Schlumpf, Yolanda R.; Reinders, Antje A. T. S.; Nijenhuis, Ellert R. S.; Luechinger, Roger; van Osch, Matthias J. P.; Jäncke, Lutz

    2014-01-01

    Background: In accordance with the Theory of Structural Dissociation of the Personality (TSDP), studies of dissociative identity disorder (DID) have documented that two prototypical dissociative subsystems of the personality, the "Emotional Part'' (EP) and the "Apparently Normal Part'' (ANP), have different biopsychosocial reactions to supraliminal and subliminal trauma-related cues and that these reactions cannot be mimicked by fantasy prone healthy controls nor by actors. Methods: Arterial ...

  8. An outpatient clinical study of dissociative disorder not otherwise specified.

    Science.gov (United States)

    Yanartaş, Ömer; Özmen, Hülya Akar; Citak, Serhat; Zincir, Selma Bozkurt; Sünbül, Esra Aydin

    2014-05-01

    The relatively high prevalence of the diagnosis of dissociative disorder not otherwise specified is frequently considered to be disproportionate. The disproportionate rate of this diagnosis is thought to be related to nosologic and/or diagnostic issues in dissociative identity disorder. We sought to investigate and compare the symptom patterns of these two clinical entities. We conducted a cross-sectional study involving 1314 participants who were screened with the Dissociative Experience Scale (DES) and the Somatoform Dissociation Questionnaire (SDQ). Of the participants, 272 who scored above the cut-off points for the screening questionnaires (DES score>30 and/or SDQ score>40 points) were invited to complete a structured interview using the Dissociative Disorders Interview Schedule (DDIS); of this subsample, only 190 participants agreed to participate in the second phase of the study. The mean score for the DES was 18.55±17.23, and the mean score for the SDQ was 30.19±13.32. Of the 190 participants, 167 patients were diagnosed as having a dissociative disorder (87.8%). We found that DD-NOS was the most prevalent category of dissociative disorder. There was a significantly larger percentage of patients in the DID group than in the DD-NOS group according to secondary features of DID and Schneiderian symptoms. The secondary features of DID and Schneiderian symptoms appeared to be more specific for DID, while no differences were detected between DID and DD-NOS based on most of the items on the SCL 90R. Further longitudinal studies are needed to determine the features that are similar and dissimilar between DD-NOS and DID. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Reaction pathways of the dissociation of methylal: A DFT study

    Energy Technology Data Exchange (ETDEWEB)

    Frey, H -M; Beaud, P; Gerber, T; Mischler, B; Radi, P P; Tzannis, A -P [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Schemata for modelling combustion processes do not yet include reaction rates for oxygenated fuels like methylal (DMM) which is considered as an additive or replacement for diesel due to its low sooting propensity. Density functional theory (DFT) studies of the possible reaction pathways for different dissociation steps of methylal are presented. Cleavage of a hydrogen bond to the methoxy group or the central carbon atom were simulated at the BLYP/6-311++G{sup **} level of theory. The results are compared to the experiment when dissociating and/or ionising DMM with femtosecond pulses. (author) 1 fig., 1 tab., 1 ref.

  10. A Validation Study of the Adolescent Dissociative Experiences Scale

    Science.gov (United States)

    Keck Seeley, Susan. M.; Perosa, Sandra, L.; Perosa, Linda, M.

    2004-01-01

    Objective: The purpose of this study was to further the validation process of the Adolescent Dissociative Experiences Scale (A-DES). In this study, a 6-item Likert response format with descriptors was used when responding to the A-DES rather than the 11-item response format used in the original A-DES. Method: The internal reliability and construct…

  11. Double dissociation in the reaction K-p→K-π+π-Nπ+ at 14.3GeV/c and pomeron factorisation

    International Nuclear Information System (INIS)

    Denegri, D.; Pons, Y.; Borg, A.; Spiro, M.; Paler, K.; Tovey, S.; Combes, C.; Shah, T.P.

    1975-01-01

    Evidence for the double dissociation process K - p→QN*1/2→(antikaon neutral* π - ) (nπ + ) at 14.3GeV/c is presented. The cross section for this process is of the order of 10μb. The production differential cross section is steep, as typical of diffractive processes, and exhibits a strong correlation between the production slope and the dissociation system mass. The mass variation of the differential cross section slope and the total cross section of the double dissociation component are consistent with the factorisable Pomeron exchange model predictions [fr

  12. Double diffractive dissociation in the reaction K-p→K-π+π-nπ+ at 14.3 GeV/c and pomeron factorisation

    International Nuclear Information System (INIS)

    Denegri, D.; Pons, Y.; Borg, A.; Spiro, M.; Paler, K.; Tovey, S.; Comber, C.; Shah, T.P.

    1975-01-01

    Evidence is presented for the double dissociation process K - p→QN*sub(1/2)→(anti K* 0 π - ) (nπ + ) at 14.3GeV/c. The cross section for the process is of the order of 10 μb. The production differential cross section is steep (for near-threshold excitation masses), as typical of diffractive processes, and exhibits a strong correlation between the production slope and the masses of the dissociated systems. The spin-parity composition and states of the two dissociation systems closely resemble those found in single dissociation, indicating that a common diffraction-like mechanism is responsible for both processes. The mass variations of the differential cross-section slope, the decay angular correlations and the total cross section of the double dissociation component are consistent with the predictions of a factorisable pomeron exchange model. (Auth.)

  13. Implicit and explicit preferences for physical attractiveness in a romantic partner: a double dissociation in predictive validity.

    Science.gov (United States)

    Eastwick, Paul W; Eagly, Alice H; Finkel, Eli J; Johnson, Sarah E

    2011-11-01

    Five studies develop and examine the predictive validity of an implicit measure of the preference for physical attractiveness in a romantic partner. Three hypotheses were generally supported. First, 2 variants of the go/no-go association task revealed that participants, on average, demonstrate an implicit preference (i.e., a positive spontaneous affective reaction) for physical attractiveness in a romantic partner. Second, these implicit measures were not redundant with a traditional explicit measure: The correlation between these constructs was .00 on average, and the implicit measures revealed no reliable sex differences, unlike the explicit measure. Third, explicit and implicit measures exhibited a double dissociation in predictive validity. Specifically, explicit preferences predicted the extent to which attractiveness was associated with participants' romantic interest in opposite-sex photographs but not their romantic interest in real-life opposite-sex speed-daters or confederates. Implicit preferences showed the opposite pattern. This research extends prior work on implicit processes in romantic relationships and offers the first demonstration that any measure of a preference for a particular characteristic in a romantic partner (an implicit measure of physical attractiveness, in this case) predicts individuals' evaluation of live potential romantic partners.

  14. Dissociative Identity Disorder in Felonious Offenders: Two Case Studies.

    Science.gov (United States)

    Culiner, Ty

    1997-01-01

    Describes the case studies of two inmates detained in a maximum security prison having been diagnosed with Dissociative Identity Disorder and receiving individual therapy. Although treatment is ongoing, mid-treatment progress indicates the treatment is successful and the prognosis is excellent. Accentuates the practicality and rewards of working…

  15. Dissociation From a Cross-Cultural Perspective: Implications of Studies in Brazil.

    Science.gov (United States)

    Maraldi, Everton de Oliveira; Krippner, Stanley; Barros, Maria Cristina Monteiro; Cunha, Alexandre

    2017-07-01

    A major issue in the study of dissociation concerns the cross-cultural validity of definitions and measurements used to identify and classify dissociative disorders. There is also extensive debate on the etiological factors underlying dissociative experiences. Cross-cultural research is essential to elucidate these issues, particularly regarding evidence obtained from countries in which the study of dissociation is still in its infancy. The aim of this article was to discuss Brazilian research on the topic of dissociation, highlighting its contributions for the understanding of dissociative experiences in nonclinical populations and for the validity and relevance of dissociative disorders in the contexts of psychiatry, psychology, and psychotherapy. We also consider the ways in which dissociative experiences are assimilated by Brazilian culture and religious expressions, and the implications of Brazilian studies for the sociocultural investigation of dissociation. We conclude by addressing the limitations of these studies and potential areas for future research.

  16. Possession experiences in dissociative identity disorder: a preliminary study.

    Science.gov (United States)

    Ross, Colin A

    2011-01-01

    Dissociative trance disorder, which includes possession experiences, was introduced as a provisional diagnosis requiring further study in the Diagnostic and Statistical Manual of Mental Disorders (4th ed.). Consideration is now being given to including possession experiences within dissociative identity disorder (DID) in the Diagnostic and Statistical Manual of Mental Disorders (5th ed.), which is due to be published in 2013. In order to provide empirical data relevant to the relationship between DID and possession states, I analyzed data on the prevalence of trance, possession states, sleepwalking, and paranormal experiences in 3 large samples: patients with DID from North America; psychiatric outpatients from Shanghai, China; and a general population sample from Winnipeg, Canada. Trance, sleepwalking, paranormal, and possession experiences were much more common in the DID patients than in the 2 comparison samples. The study is preliminary and exploratory in nature because the samples were not matched in any way.

  17. Body knowledge in brain-damaged children: a double-dissociation in self and other's body processing.

    Science.gov (United States)

    Frassinetti, Francesca; Fiori, Simona; D'Angelo, Valentina; Magnani, Barbara; Guzzetta, Andrea; Brizzolara, Daniela; Cioni, Giovanni

    2012-01-01

    Bodies are important element for self-recognition. In this respect, in adults it has been recently shown a self vs other advantage when small parts of the subjects' body are visible. This advantage is lost following a right brain lesion underlying a role of the right hemisphere in self body-parts processing. In order to investigate the bodily-self processing in children and the development of its neuronal bases, 57 typically developing healthy subjects and 17 subjects with unilateral brain damage (5 right and 12 left sided), aged 4-17 years, were submitted to a matching-to-sample task. In this task, three stimuli vertically aligned were simultaneously presented at the centre of the computer screen. Subjects were required which of two stimuli (the upper or the lower one) matched the central target stimulus, half stimuli representing self and half stimuli representing other people's body-parts and face-parts. The results showed that corporeal self recognition is present since at least 4 years of age and that self and others' body parts processing are different and sustained by separate cerebral substrates. Indeed, a double dissociation was found: right brain damaged patients were impaired in self but not in other people's body parts, showing a self-disadvantage, whereas left brain damaged patients were impaired in others' but not in self body parts processing. Finally, since the double dissociation self/other was found for body-parts but not for face parts, the corporal self seems to be dissociated for body and face-parts. This opens the possibility of independent and lateralized functional modules for the processing of self and other body parts during development. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Molecular treatment of single (dissociative and nondissociative) and double electron capture in He2+ + H2 collisions

    International Nuclear Information System (INIS)

    Errea, L F; Macias, A; Mendez, L; Pons, B; Riera, A

    2003-01-01

    We present close-coupling calculations of total cross sections for single and double electron capture in He 2+ + H 2 collisions in the range 0.5- 25 keV amu -1 , and compare them with experimental data. We confirm the experimental finding that the dominant process for E ∼> 3 keV amu -1 is the nondissociative capture He 2+ + H 2 → He + (2l) + H 2 + (1σ g ), while at lower energies it is dissociative capture leading to He + (1s) + H + + H. Our calculations also show that He(1s2l) is the main output of the two electron capture process. (letter to the editor)

  19. Dissociative double ionization of H2 and D2: Comparison between experiment and Monte Carlo wave packet calculations

    DEFF Research Database (Denmark)

    Leth, Henriette Astrup; Madsen, Lars Bojer; Mølmer, Klaus

    2010-01-01

    Theoretical calculations on dissociative double ionization of H2 and D2 in short intense laser pulses using the Monte Carlo wave packet technique are presented for several different field intensities, wavelengths, and pulse durations. We find convincing agreement between theory and experimental...... results for the kinetic energy release spectra of the nuclei. Besides the correctly predicted spectra the Monte Carlo wave packet method offers insight into the nuclear dynamics during the pulse and makes it possible to address the origin of different structures observed in the spectra. Three......-photon resonances in the singly ionized molecule and charge-resonance-enhanced ionization are shown to be the main processes responsible for the observed nuclear energy distributions....

  20. Dissociation of polycyclic aromatic hydrocarbons: molecular dynamics studies

    Science.gov (United States)

    Simon, A.; Rapacioli, M.; Rouaut, G.; Trinquier, G.; Gadéa, F. X.

    2017-03-01

    We present dynamical studies of the dissociation of polycyclic aromatic hydrocarbon (PAH) radical cations in their ground electronic states with significant internal energy. Molecular dynamics simulations are performed, the electronic structure being described on-the-fly at the self-consistent-charge density functional-based tight binding (SCC-DFTB) level of theory. The SCC-DFTB approach is first benchmarked against DFT results. Extensive simulations are achieved for naphthalene , pyrene and coronene at several energies. Such studies enable one to derive significant trends on branching ratios, kinetics, structures and hints on the formation mechanism of the ejected neutral fragments. In particular, dependence of branching ratios on PAH size and energy were retrieved. The losses of H and C2H2 (recognized as the ethyne molecule) were identified as major dissociation channels. The H/C2H2 ratio was found to increase with PAH size and to decrease with energy. For , which is the most interesting PAH from the astrophysical point of view, the loss of H was found as the quasi-only channel for an internal energy of 30 eV. Overall, in line with experimental trends, decreasing the internal energy or increasing the PAH size will favour the hydrogen loss channels with respect to carbonaceous fragments. This article is part of the themed issue 'Theoretical and computational studies of non-equilibrium and non-statistical dynamics in the gas phase, in the condensed phase and at interfaces'.

  1. Monte Carlo Wave Packet Theory of Dissociative Double Ionization

    DEFF Research Database (Denmark)

    Leth, Henriette Astrup; Madsen, Lars Bojer; Mølmer, Klaus

    2009-01-01

    Nuclear dynamics in strong-field double ionization processes is predicted using a stochastic Monte Carlo wave packet technique. Using input from electronic structure calculations and strong-field electron dynamics the description allows for field-dressed dynamics within a given molecule as well...

  2. Evidence for a double dissociation of articulatory rehearsal and non-articulatory maintenance of phonological information in human verbal working memory.

    Science.gov (United States)

    Trost, Sarah; Gruber, Oliver

    2012-01-01

    Recent functional neuroimaging studies have provided evidence that human verbal working memory is represented by two complementary neural systems, a left lateralized premotor-parietal network implementing articulatory rehearsal and a presumably phylogenetically older bilateral anterior-prefrontal/inferior-parietal network subserving non-articulatory maintenance of phonological information. In order to corroborate these findings from functional neuroimaging, we performed a targeted behavioural study in patients with very selective and circumscribed brain lesions to key regions suggested to support these different subcomponents of human verbal working memory. Within a sample of over 500 neurological patients assessed with high-resolution structural magnetic resonance imaging, we identified 2 patients with corresponding brain lesions, one with an isolated lesion to Broca's area and the other with a selective lesion bilaterally to the anterior middle frontal gyrus. These 2 patients as well as groups of age-matched healthy controls performed two circuit-specific verbal working memory tasks. In this way, we systematically assessed the hypothesized selective behavioural effects of these brain lesions on the different subcomponents of verbal working memory in terms of a double dissociation. Confirming prior findings, the lesion to Broca's area led to reduced performance under articulatory rehearsal, whereas the non-articulatory maintenance of phonological information was unimpaired. Conversely, the bifrontopolar brain lesion was associated with impaired non-articulatory phonological working memory, whereas performance under articulatory rehearsal was unaffected. The present experimental neuropsychological study in patients with specific and circumscribed brain lesions confirms the hypothesized double dissociation of two complementary brain systems underlying verbal working memory in humans. In particular, the results demonstrate the functional relevance of the anterior

  3. A storage ring study of dissociative excitation and recombination of D3+

    International Nuclear Information System (INIS)

    Le Padellec, A.; Larson, Aa.; Semaniak, J.; Stroemholm, C.; Larsson, M.; Rosen, S.; Danared, H.; Peterson, J.R.

    1998-01-01

    Dissociative recombination and excitation of D 3 + have been studied in CRYRING, a heavy-ion storage ring at the Manne Siegbahn laboratory at Stockholm University. The measured cross section for dissociative recombination was used to deduce a 300 K rate constant of 2.7 x 10 -8 cm 3 s -1 . This is a factor of four smaller than the corresponding value for H 3 + measured earlier in CRYRING. Dissociative excitation into both the D and 2D channels (D + D or D 2 ) were studied. The 2D channel occurs at energies below threshold for the ion's dissociative states, which indicates that resonant enhanced dissociative excitation via autoionizing resonances takes place. No measurable effect could be observed for the dissociative recombination cross sections when an electric field of 30 V/cm was applied to the electron-ion interaction region. (orig.)

  4. Dissociative part-dependent resting-state activity in dissociative identity disorder: a controlled FMRI perfusion study.

    Science.gov (United States)

    Schlumpf, Yolanda R; Reinders, Antje A T S; Nijenhuis, Ellert R S; Luechinger, Roger; van Osch, Matthias J P; Jäncke, Lutz

    2014-01-01

    In accordance with the Theory of Structural Dissociation of the Personality (TSDP), studies of dissociative identity disorder (DID) have documented that two prototypical dissociative subsystems of the personality, the "Emotional Part" (EP) and the "Apparently Normal Part" (ANP), have different biopsychosocial reactions to supraliminal and subliminal trauma-related cues and that these reactions cannot be mimicked by fantasy prone healthy controls nor by actors. Arterial spin labeling perfusion MRI was used to test the hypotheses that ANP and EP in DID have different perfusion patterns in response to rest instructions, and that perfusion is different in actors who were instructed to simulate ANP and EP. In a follow-up study, regional cerebral blood flow of DID patients was compared with the activation pattern of healthy non-simulating controls. Compared to EP, ANP showed elevated perfusion in bilateral thalamus. Compared to ANP, EP had increased perfusion in the dorsomedial prefrontal cortex, primary somatosensory cortex, and motor-related areas. Perfusion patterns for simulated ANP and EP were different. Fitting their reported role-play strategies, the actors activated brain structures involved in visual mental imagery and empathizing feelings. The follow-up study demonstrated elevated perfusion in the left temporal lobe in DID patients, whereas non-simulating healthy controls had increased activity in areas which mediate the mental construction of past and future episodic events. DID involves dissociative part-dependent resting-state differences. Compared to ANP, EP activated brain structures involved in self-referencing and sensorimotor actions more. Actors had different perfusion patterns compared to genuine ANP and EP. Comparisons of neural activity for individuals with DID and non-DID simulating controls suggest that the resting-state features of ANP and EP in DID are not due to imagination. The findings are consistent with TSDP and inconsistent with the idea

  5. Dissociative part-dependent resting-state activity in dissociative identity disorder: a controlled FMRI perfusion study.

    Directory of Open Access Journals (Sweden)

    Yolanda R Schlumpf

    Full Text Available In accordance with the Theory of Structural Dissociation of the Personality (TSDP, studies of dissociative identity disorder (DID have documented that two prototypical dissociative subsystems of the personality, the "Emotional Part" (EP and the "Apparently Normal Part" (ANP, have different biopsychosocial reactions to supraliminal and subliminal trauma-related cues and that these reactions cannot be mimicked by fantasy prone healthy controls nor by actors.Arterial spin labeling perfusion MRI was used to test the hypotheses that ANP and EP in DID have different perfusion patterns in response to rest instructions, and that perfusion is different in actors who were instructed to simulate ANP and EP. In a follow-up study, regional cerebral blood flow of DID patients was compared with the activation pattern of healthy non-simulating controls.Compared to EP, ANP showed elevated perfusion in bilateral thalamus. Compared to ANP, EP had increased perfusion in the dorsomedial prefrontal cortex, primary somatosensory cortex, and motor-related areas. Perfusion patterns for simulated ANP and EP were different. Fitting their reported role-play strategies, the actors activated brain structures involved in visual mental imagery and empathizing feelings. The follow-up study demonstrated elevated perfusion in the left temporal lobe in DID patients, whereas non-simulating healthy controls had increased activity in areas which mediate the mental construction of past and future episodic events.DID involves dissociative part-dependent resting-state differences. Compared to ANP, EP activated brain structures involved in self-referencing and sensorimotor actions more. Actors had different perfusion patterns compared to genuine ANP and EP. Comparisons of neural activity for individuals with DID and non-DID simulating controls suggest that the resting-state features of ANP and EP in DID are not due to imagination. The findings are consistent with TSDP and inconsistent

  6. A Double Dissociation between Anterior and Posterior Superior Temporal Gyrus for Processing Audiovisual Speech Demonstrated by Electrocorticography.

    Science.gov (United States)

    Ozker, Muge; Schepers, Inga M; Magnotti, John F; Yoshor, Daniel; Beauchamp, Michael S

    2017-06-01

    Human speech can be comprehended using only auditory information from the talker's voice. However, comprehension is improved if the talker's face is visible, especially if the auditory information is degraded as occurs in noisy environments or with hearing loss. We explored the neural substrates of audiovisual speech perception using electrocorticography, direct recording of neural activity using electrodes implanted on the cortical surface. We observed a double dissociation in the responses to audiovisual speech with clear and noisy auditory component within the superior temporal gyrus (STG), a region long known to be important for speech perception. Anterior STG showed greater neural activity to audiovisual speech with clear auditory component, whereas posterior STG showed similar or greater neural activity to audiovisual speech in which the speech was replaced with speech-like noise. A distinct border between the two response patterns was observed, demarcated by a landmark corresponding to the posterior margin of Heschl's gyrus. To further investigate the computational roles of both regions, we considered Bayesian models of multisensory integration, which predict that combining the independent sources of information available from different modalities should reduce variability in the neural responses. We tested this prediction by measuring the variability of the neural responses to single audiovisual words. Posterior STG showed smaller variability than anterior STG during presentation of audiovisual speech with noisy auditory component. Taken together, these results suggest that posterior STG but not anterior STG is important for multisensory integration of noisy auditory and visual speech.

  7. Dissociation of the Phenylarsane Molecular Ion: A Theoretical Study

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sun Young; Choe, Joong Chul [Dongguk University, Seoul (Korea, Republic of)

    2010-09-15

    The potential energy surfaces (PESs) for the primary and secondary dissociations of the phenylarsane molecular ion (1a) were determined from the quantum chemical calculations using the G3(MP2)//B3LYP method. Several pathways for the loss of H· were determined and occurred though rearrangements as well as through direct bond cleavages. The kinetic analysis based on the PES for the primary dissociation showed that the loss of H{sub 2} was more favored than the loss of H·, but the H· loss competed with the H{sub 2} loss at high energies. The bicyclic isomer, 7-arsa-norcaradiene radical cation, was formed through the 1,2 shift of an α-H of 1a and played an important role as an intermediate for the further rearrangements in the loss of H· and the losses of As· and AsH. The reaction pathways for the formation of the major products in the secondary dissociations of [M-H]{sup +} and [M-H{sub 2}]{sup +·} were examined. The theoretical prediction explained the previous experimental results for the dissociation at high energies but not the dissociation at low energies.

  8. Dissociative symptoms and sleep parameters--an all-night polysomnography study in patients with insomnia.

    Science.gov (United States)

    Van Der Kloet, Dalena; Giesbrecht, Timo; Franck, Erik; Van Gastel, Ann; De Volder, Ilse; Van Den Eede, Filip; Verschuere, Bruno; Merckelbach, Harald

    2013-08-01

    Dissociative disorders encompass a range of symptoms varying from severe absent-mindedness and memory problems to confusion about one's own identity. Recent studies suggest that these symptoms may be the by-products of a labile sleep-wake cycle. In the current study, we explored this issue in patients suffering from insomnia (N=46). We investigated whether these patients have raised levels of dissociative symptoms and whether these are related to objective sleep parameters. Patients stayed for at least one night in a specialized sleep clinic, while sleep EEG data were obtained. In addition, they completed self-report measures on dissociative symptoms, psychological problems, and sleep characteristics. Dissociative symptom levels were elevated in patients suffering from insomnia, and were correlated with unusual sleep experiences and poor sleep quality. Longer REM sleep periods and less time spent awake during the night were predictive of dissociation. This is the first study to show that insomnia patients have raised dissociative symptom levels and that their dissociative symptoms are related to objective EEG parameters. These findings are important because they may inspire sleep-related treatment methods for dissociative disorders. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Differential Relationships between RAN Performance, Behaviour Ratings, and Executive Function Measures: Searching for a Double Dissociation

    Science.gov (United States)

    Stringer, Ronald W.; Toplak, Maggie E.; Stanovich, Keith E.

    2004-01-01

    In this study, we investigated the relationships between rapid naming of letters, digits and colours, and reading ability and executive function. We gave fifty-six grade three and four children rapid automatised naming tasks using letters and digits as stimuli, executive function measures including the Stroop task, a working memory task and the…

  10. Comparative study between hadron and heavy ion dissociation at high energies

    International Nuclear Information System (INIS)

    El-Bakry, Y.M.N.; Abd-Elhalim, S.M.

    2002-01-01

    The present work deals with the dissociation of hadrons and heavy ions at high energies. In investigating hadron nucleus and nucleus-nucleus collisions, it is important to classify the experimental data, into two main classes; the coherent. and incoherent reactions. The coherent production is the main of our study. This process called electromagnetic dissociation (ED) and can be differentiate into coulomb dissociation (CD) and diffraction dissociation (DD). This work explains the experimental data of collisions of hadrons K± (70 GeV/c) and π(340 Gc V/c) and heavy ions 6 L i, 7 L i, 1 2C and1 6O at Dubna energies (3-4.5 A GeV/c)with emulsion target, in the frame of some models and theories which describe the mechanism of ED dissociation

  11. A double dissociation of implicit and explicit memory in younger and older adults.

    Science.gov (United States)

    Gopie, Nigel; Craik, Fergus I M; Hasher, Lynn

    2011-05-01

    This study examined whether age-related differences in cognition influence later memory for irrelevant, or distracting, information. In Experiments 1 and 2, older adults had greater implicit memory for irrelevant information than younger adults did. When explicit memory was assessed, however, the pattern of results reversed: Younger adults performed better than older adults on an explicit memory test for the previously irrelevant information, and older adults performed less well than they had on the implicit test. Experiment 3 investigated whether this differential pattern was attributable to an age-related decline in encoding resources, by reducing the encoding resources of younger adults with a secondary task; their performance perfectly simulated the pattern shown by the older adults in the first two experiments. Both older and younger adults may remember irrelevant information, but they remember it in different ways because of age-related changes in how information is processed at encoding and utilized at retrieval.

  12. Observation of double-well potential of NaH C 1Σ+ state: Deriving the dissociation energy of its ground state.

    Science.gov (United States)

    Chu, Chia-Ching; Huang, Hsien-Yu; Whang, Thou-Jen; Tsai, Chin-Chun

    2018-03-21

    Vibrational levels (v = 6-42) of the NaH C 1 Σ + state including the inner and outer wells and the near-dissociation region were observed by pulsed optical-optical double resonance fluorescence depletion spectroscopy. The absolute vibrational quantum number is identified by comparing the vibrational energy difference of this experiment with the ab initio calculations. The outer well with v up to 34 is analyzed using the Dunham expansion and a Rydberg-Klein-Rees (RKR) potential energy curve is constructed. A hybrid double-well potential combined with the RKR potential, the ab initio calculation, and a long-range potential is able to describe the whole NaH C 1 Σ + state including the higher vibrational levels (v = 35-42). The dissociation energy of the NaH C 1 Σ + state is determined to be D e (C) = 6595.10 ± 5 cm -1 and then the dissociation energy of the NaH ground state D e (X) = 15 807.87 ± 5 cm -1 can be derived.

  13. The application of "double isolation" in Fourier transform ion cyclotron resonance sustained off-resonance irradiation collisionally-induced dissociation tandem mass spectrometry to remove labile isobaric impurities.

    Science.gov (United States)

    Gates, Paul J; Lopes, Norberto P; Pinto, Emani; Colepicolo, Pio; Cardozo, Karina H M

    2011-01-01

    This study reports the application of "double isolation" in sustained off-resonance irradiation collisionally-induced dissociation tandem mass spectrometry (SORI-CID-MS/MS) to remove radio- frequency (RF) fragment ions of very close mass isobaric ions (0.02 m/z apart). Analyses were performed with a fraction of a biological extract isolated from a macroalgae containing the mycosporine-like amino acid asterina-330. Direct isolation of the precursor ion by narrowing the isolation window proved ineffective as it impinged upon the required ion thus substantially reducing its intensity. By increasing the correlated sweep time, ejection efficiency of the isolation was improved, but caused the unwanted side-effect of RF fragmentation of labile ions. Finally, by skipping the ion activation step and performing a second isolation (in the MS(3) module) the RF fragments from the first isolation were removed leaving a very pure isolation of the required precursor ion and allowed a very clean CID fragmentation. We demonstrated that the m/z 272.1351 ion is derived from the loss of NH(3) from m/z 289.1620 isobaric impurity and is not related to asterina-330. This application represents a powerful tool to remove unwanted ions in the MS/MS spectrum that result from fragmentation of isobaric ions.

  14. A double dissociation of dorsal and ventral hippocampal function on a learning and memory task mediated by the dorso-lateral striatum.

    Science.gov (United States)

    McDonald, Robert J; Jones, Jana; Richards, Blake; Hong, Nancy S

    2006-09-01

    The objectives of this research were to further delineate the neural circuits subserving proposed memory-based behavioural subsystems in the hippocampal formation. These studies were guided by anatomical evidence showing a topographical organization of the hippocampal formation. Briefly, perpendicular to the medial/lateral entorhinal cortex division there is a second system of parallel circuits that separates the dorsal and ventral hippocampus. Recent work from this laboratory has provided evidence that the hippocampus incidentally encodes a context-specific inhibitory association during acquisition of a visual discrimination task. One question that emerges from this dataset is whether the dorsal or ventral hippocampus makes a unique contribution to this newly described function. Rats with neurotoxic lesions of the dorsal or ventral hippocampus were assessed on the acquisition of the visual discrimination task. Following asymptotic performance they were given reversal training in either the same or a different context from the original training. The results showed that the context-specific inhibition effect is mediated by a circuit that includes the ventral but not the dorsal hippocampus. Results from a control procedure showed that rats with either dorso-lateral striatum damage or dorsal hippocampal lesions were impaired on a tactile/spatial discrimination. Taken together, the results represent a double dissociation of learning and memory function between the ventral and dorsal hippocampus. The formation of an incidental inhibitory association was dependent on ventral but not dorsal hippocampal circuitry, and the opposite dependence was found for the spatial component of a tactile/spatial discrimination.

  15. Feature-based attention is functionally distinct from relation-based attention: The double dissociation between color-based capture and color-relation-based capture of attention.

    Science.gov (United States)

    Du, Feng; Jiao, Jun

    2016-04-01

    The present study used a spatial blink task and a cuing task to examine the boundary between feature-based capture and relation-based capture. Feature-based capture occurs when distractors match the target feature such as target color. The occurrence of relation-based capture is contingent upon the feature relation between target and distractor (e.g., color relation). The results show that color distractors that match the target-nontarget color relation do not consistently capture attention when they appear outside of the attentional window, but distractors appearing outside the attentional window that match the target color consistently capture attention. In contrast, color distractors that best match the target-nontarget color relation but not the target color, are more likely to capture attention when they appear within the attentional window. Consistently, color cues that match the target-nontarget color relation produce a cuing effect when they appear within the attentional window, while target-color matched cues do not. Such a double dissociation between color-based capture and color-relation-based capture indicates functionally distinct mechanisms for these 2 types of attentional selection. This also indicates that the spatial blink task and the uninformative cuing task are measuring distinctive aspects of involuntary attention. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  16. VUV Study of Electron-Pyrimidine Dissociative Excitation

    Science.gov (United States)

    Hein, Jeff; Al-Khazraji, Hajar; Tiessen, Collin; Lukic, Dragan; Trocchi, Joshuah; McConkey, William

    2013-05-01

    A crossed electron-gas beam system coupled to a VUV spectrometer has been used to investigate the dissociation of pyrimidine (C4H4N2) into excited atomic fragments in the electron-impact energy range from threshold to 375 eV. Data have been made absolute using Lyman- α from H2 as a secondary standard. The main features in the spectrum are the H Lyman series lines. The emission cross section of Lyman- α is measured to be (2.44 +/- 0.25) 10-18 cm2 at 100 eV impact energy. The probability of extracting C or N atoms from the ring is shown to be very small. Possible dissociation channels and excitation mechanisms in the parent molecule will be discussed. The authors thank NSERC (Canada) for financial support.

  17. Photoionization and dissociative photoionization study of HFC-152a using synchrotron radiation

    International Nuclear Information System (INIS)

    Huang Chaoqun; Wei Lixia; Yang Bin; Yang Rui; Wang Sisheng; Shan Xiaobin; Qi Fei; Zhang Yunwu; Sheng Liusi; Hao Liqing; Zhou Shikang; Wang Zhenya

    2006-01-01

    Photoionization and dissociative photoionization of HFC-152a have been studied using synchrotron radiation and a reflection time-of-flight mass spectrometry (RTOF-MS). The ionization energy of parent molecule (11.94 ± 0.04 eV) and appearance potentials of various fragment ions have been determined by measuring their photoionization efficiency curves. Energies, symmetry point groups and ground electronic states of neutrals and cations of parent and its fragments have been calculated using GAUSSIAN-03 program with the G3 method. According to the theoretical and experimental results, some dissociation channels and their dissociation energies of CH 3 CHF 2 + have been analyzed. (authors)

  18. Dissociation, personality, suggestibility, alexithymia, and problems with emotional regulation: A correlational study

    Directory of Open Access Journals (Sweden)

    Ángeles Serrano

    2016-12-01

    Full Text Available The present paper explores the relationship between psychological and somatic dissociation and different personality and emotional variables, including suggestibility, alexithymia, and emotional regulation and dysregulation. The results with a sample of 355 partipants of a normal population reveal that there is a positive relationship between both types of dissociation, suggestibility and emotional dysregulation. Likewise, there were different patterns of personality associated both to psychological and somatic dissociation. Correlations found in this study put forward the importance to take into account both types of dissociactive symptoms, psychological and somatic ones.

  19. Testing the diagnosis of dissociative identity disorder through measures of dissociation, absorption, hypnotizability and PTSD: a Norwegian pilot study.

    Science.gov (United States)

    Dale, Karl Yngvar; Berg, Renate; Elden, Ake; Ødegård, Atle; Holte, Arne

    2009-01-01

    A total of 14 women meeting criteria for dissociative identity disorder (DID) based on the Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV]) were compared to a group of women (n = 10) with other dissociative diagnoses and a group of normal controls (n = 14) with regard to dissociativity, absorption, trauma related symptoms and hypnotizability. Both of the clinical groups reported histories of childhood trauma and attained high PTSD scores. The DID group differed significantly from the group with other dissociative diagnoses and the non-diagnosed comparison group with regard to hypnotizability, the variety of dissociative symptomatology, and the magnitude of dissociative symptomatology. However, no significant differences between the two clinical groups were detected with regard to absorption, general dissociative level, or symptoms related to traumatic stress. Results support the notion that DID can be regarded as a clinical entity which is separable from other dissociative disorders. Results also indicated that hypnotizability is the most important clinical feature of DID.

  20. Photoleucine Survives Backbone Cleavage by Electron Transfer Dissociation. A Near-UV Photodissociation and Infrared Multiphoton Dissociation Action Spectroscopy Study

    Czech Academy of Sciences Publication Activity Database

    Shaffer, C. J.; Martens, J.; Marek, Aleš; Oomens, J.; Tureček, F.

    2016-01-01

    Roč. 27, č. 7 (2016), s. 1176-1185 ISSN 1044-0305 Institutional support: RVO:61388963 Keywords : peptide ions * electron transfer dissociation * photoleucine label * near-UV photodissociation * infrared multiphoton dissociation action spectroscopy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.786, year: 2016

  1. Experimental dissociation of individual quality, food and timing of breeding effects on double-brooding in a migratory songbird.

    Science.gov (United States)

    O'Brien, Erin L; Dawson, Russell D

    2013-07-01

    Annual reproductive success in many species is influenced by the number of breeding attempts within a season. Although previous studies have shown isolated effects of female quality, food, and timing of breeding on the probability of female birds producing second broods, to our knowledge, none have tested the relative importance of multiple factors and their interactions using simultaneous manipulations within populations of free-living birds. In this study, we show that individual quality and timing of breeding interact to affect the probability of double-brooding in female mountain bluebirds (Sialia currucoides). High-quality females (those that naturally initiated clutches early in the season) were more likely to double-brood, regardless of whether their hatching date was advanced or delayed, whereas later breeding, lower quality females were much less likely to double-brood when their first attempt was delayed. This indicates that annual fecundity of poorer quality (or younger) female bluebirds may be more sensitive to seasonal variation in environmental conditions. In addition, birds that were provided with supplemental food throughout first breeding attempts were more likely to double-brood in one of the study years, suggesting that female bluebirds may be energetically limited in their capacity to initiate a second brood. Females that had their first brood delayed also had a shorter inter-brood interval and were moulting fewer feathers during second broods compared to controls, while females in better condition showed more advanced moult in second breeding attempts. Taken together, our results demonstrate the combined effects of age- or individual quality-mediated energetic trade-offs between current and future reproduction, and between investments in offspring and self-maintenance, on annual fecundity of female birds.

  2. Dissociable genetic contributions to error processing: a multimodal neuroimaging study.

    Directory of Open Access Journals (Sweden)

    Yigal Agam

    Full Text Available Neuroimaging studies reliably identify two markers of error commission: the error-related negativity (ERN, an event-related potential, and functional MRI activation of the dorsal anterior cingulate cortex (dACC. While theorized to reflect the same neural process, recent evidence suggests that the ERN arises from the posterior cingulate cortex not the dACC. Here, we tested the hypothesis that these two error markers also have different genetic mediation.We measured both error markers in a sample of 92 comprised of healthy individuals and those with diagnoses of schizophrenia, obsessive-compulsive disorder or autism spectrum disorder. Participants performed the same task during functional MRI and simultaneously acquired magnetoencephalography and electroencephalography. We examined the mediation of the error markers by two single nucleotide polymorphisms: dopamine D4 receptor (DRD4 C-521T (rs1800955, which has been associated with the ERN and methylenetetrahydrofolate reductase (MTHFR C677T (rs1801133, which has been associated with error-related dACC activation. We then compared the effects of each polymorphism on the two error markers modeled as a bivariate response.We replicated our previous report of a posterior cingulate source of the ERN in healthy participants in the schizophrenia and obsessive-compulsive disorder groups. The effect of genotype on error markers did not differ significantly by diagnostic group. DRD4 C-521T allele load had a significant linear effect on ERN amplitude, but not on dACC activation, and this difference was significant. MTHFR C677T allele load had a significant linear effect on dACC activation but not ERN amplitude, but the difference in effects on the two error markers was not significant.DRD4 C-521T, but not MTHFR C677T, had a significant differential effect on two canonical error markers. Together with the anatomical dissociation between the ERN and error-related dACC activation, these findings suggest that

  3. 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

  4. Studies of neutron dissociation at FermiLab energies

    International Nuclear Information System (INIS)

    Ferbel, T.

    1975-01-01

    The characteristics of diffraction dissociation of neutrons into pπ - systems at high energies were examined. A substantial correlation is observed between the mass and the t of the produced system. The spin structure of the pπ - amplitudes at low mass is very complex, but is described surprisingly well by the simple Deck Mechanism. Both π-exchange and proton-exchange contributions are evident in diffractive production. The t-channel and s-channel helicity amplitudes contain comparable contributions from flip and nonflip terms and the produced states are not restricted to those expected on the basis of the Morrison rule

  5. Identifying dissociative identity disorder: a self-report and projective study.

    Science.gov (United States)

    Scroppo, J C; Drob, S L; Weinberger, J L; Eagle, P

    1998-05-01

    This study compared 21 female adult psychiatric patients diagnosed with dissociative identity disorder (DID) with 21 female adult nondissociative psychiatric patients to determine whether DID patients exhibit a distinguishing set of clinical features, and perceptual, attentional, and cognitive processes. Participants were assessed with the Dissociative Disorders Interview Schedule to assess diagnostic status. Group scores on the Dissociative Experiences Scale, Tellegen Absorption Scale, Childhood Trauma Questionnaire, Brief Symptom Inventory, and the Rorschach test were compared. DID participants reported earlier and more severe childhood trauma, more dissociative symptoms, and a greater propensity for altered states of consciousness. The DID participants also exhibited increased projective and imaginative activity, a diminished ability to integrate mental contents, a complex and driven cognitive style, and a highly unconventional view of reality.

  6. Isotope exchange study of the dissociation of metal-humic substance complexes

    International Nuclear Information System (INIS)

    Mizera, J.; Jansova, A.; Hvozdova, I.; Benes, P.; Novak, F.

    2003-01-01

    Isotope exchange was employed to study dissociation of metal cations from their complexes with humic substances (HS). Dissociation of cation from HS controls the rate of isotope exchange between two identical metal-HS solutions (but for the presence of a radiotracer) divided by a dialysis membrane. The rate of isotope exchange of Eu/ 152 Eu and Co/ 60 Co in the systems with various HS was monitored as a function of pH, ionic strength, and the degree of HS loading with metal. The apparent rate of Eu-HS dissociation was found to be enhanced by decreasing pH, increasing ionic strength, and increasing metal loading. Co-HS dissociation was too fast to be followed by the method. For interpretation of the experimental kinetic data, the multiple first order law has been applied. Based on the results, a concept of HS as a mixture of two types of binding sites is discussed. (author)

  7. Psychological Dissection of Patients Having Dissociative Disorder: A Cross-sectional Study.

    Science.gov (United States)

    Reddy, Lohit Somashekar; Patil, N M; Nayak, Raghavendra B; Chate, Sameeran S; Ansari, Saba

    2018-01-01

    Patients present with dissociative disorders as a decompensation to underlying stressful situation. It is clinically important to evaluate the presence, type, and temporal relation of the stressors resulting in dissociation. Further knowing the sociodemographic and psychological profile of the dissociative patient helps in better management. The study included 55 dissociative patients aged between 5 to 45 years. Psychiatric diagnosis was made using ICD-10 DCR. Psychosocial stressors and stressful life events were assessed using presumptive stressful life events scale/life events scale for Indian children and clinical interview. Personality and temperament traits were assessed using medico psychological questionnaire and temperament measurement schedule, respectively. Intelligence quotient (IQ) was assessed using standard progressive matrices and colored progressive matrices. Statistical analysis was done using Epi Info 7 software. All patients had significant psychosocial stressors preceding dissociation. Precipitating factor with temporal association was observed in only 83.64%. Family disharmony (41.82%) followed by education-related problems (29.09%) was the most common psychosocial stressors. 61.82% of the dissociative patients had psychiatric comorbidity. Mean IQ of study sample was 92.47. Dissociative children had high emotionality and energy levels but low sociability, rhythmicity, and distractibility. 50% of the adults were neurotic and had emotionally unstable personality. Dissociative disorders are commonly seen in females, adolescents, and in those from lower socioeconomic status and rural areas. They are always preceded by psychosocial stressors. Most of them have comorbid psychiatric disorders such as depression and anxiety. Neuroticism and emotionally unstable personality traits are common in adult patients while temperamental traits such as low sociability, low rhythmicity, low distractibility, high emotionality, and high energy levels are common in

  8. A High Temperature Experimental and Theoretical Study of the Unimolecular Dissociation of 1,3,5-Trioxane

    KAUST Repository

    Alquaity, Awad B. S.; Giri, Binod Raj; Lo, John M.H.; Farooq, Aamir

    2015-01-01

    Unimolecular dissociation of 1,3,5-trioxane was investigated experimentally and theoretically over a wide range of conditions. Experiments were performed behind reflected shock waves over the temperature range of 775-1082 K and pressures near 900 Torr using a high-repetition rate time of flight mass spectrometer (TOF-MS) coupled to a shock tube (ST). Reaction products were identified directly, and it was found that formaldehyde is the sole product of 1,3,5-trioxane dissociation. Reaction rate coefficients were extracted by the best fit to the experimentally measured concentration-time histories. Additionally, high-level quantum chemical and RRKM calculations were employed to study the falloff behavior of 1,3,5-trioxane dissociation. Molecular geometries and frequencies of all species were obtained at the B3LYP/cc-pVTZ, MP2/cc-pVTZ, and MP2/aug-cc-pVDZ levels of theory, whereas the single-point energies of the stationary points were calculated using coupled cluster with single and double excitations including the perturbative treatment of triple excitation (CCSD(T)) level of theory. It was found that the dissociation occurs via a concerted mechanism requiring an energy barrier of 48.3 kcal/mol to be overcome. The new experimental data and theoretical calculations serve as a validation and extension of kinetic data published earlier by other groups. Calculated values for the pressure limiting rate coefficient can be expressed as log10 k∞ (s-1) = [15.84 - (49.54 (kcal/mol)/2.3RT)] (500-1400 K). © 2015 American Chemical Society.

  9. A High Temperature Experimental and Theoretical Study of the Unimolecular Dissociation of 1,3,5-Trioxane

    KAUST Repository

    Alquaity, Awad B. S.

    2015-05-15

    Unimolecular dissociation of 1,3,5-trioxane was investigated experimentally and theoretically over a wide range of conditions. Experiments were performed behind reflected shock waves over the temperature range of 775-1082 K and pressures near 900 Torr using a high-repetition rate time of flight mass spectrometer (TOF-MS) coupled to a shock tube (ST). Reaction products were identified directly, and it was found that formaldehyde is the sole product of 1,3,5-trioxane dissociation. Reaction rate coefficients were extracted by the best fit to the experimentally measured concentration-time histories. Additionally, high-level quantum chemical and RRKM calculations were employed to study the falloff behavior of 1,3,5-trioxane dissociation. Molecular geometries and frequencies of all species were obtained at the B3LYP/cc-pVTZ, MP2/cc-pVTZ, and MP2/aug-cc-pVDZ levels of theory, whereas the single-point energies of the stationary points were calculated using coupled cluster with single and double excitations including the perturbative treatment of triple excitation (CCSD(T)) level of theory. It was found that the dissociation occurs via a concerted mechanism requiring an energy barrier of 48.3 kcal/mol to be overcome. The new experimental data and theoretical calculations serve as a validation and extension of kinetic data published earlier by other groups. Calculated values for the pressure limiting rate coefficient can be expressed as log10 k∞ (s-1) = [15.84 - (49.54 (kcal/mol)/2.3RT)] (500-1400 K). © 2015 American Chemical Society.

  10. Psychobiological characteristics of dissociative identity disorder: a symptom provocation study.

    Science.gov (United States)

    Reinders, A A T Simone; Nijenhuis, Ellert R S; Quak, Jacqueline; Korf, Jakob; Haaksma, Jaap; Paans, Anne M J; Willemsen, Antoon T M; den Boer, Johan A

    2006-10-01

    Dissociative identity disorder (DID) patients function as two or more identities or dissociative identity states (DIS), categorized as 'neutral identity states' (NIS) and 'traumatic identity states' (TIS). NIS inhibit access to traumatic memories thereby enabling daily life functioning. TIS have access and responses to these memories. We tested whether these DIS show different psychobiological reactions to trauma-related memory. A symptom provocation paradigm with 11 DID patients was used in a two-by-two factorial design setting. Both NIS and TIS were exposed to a neutral and a trauma-related memory script. Three psychobiological parameters were tested: subjective ratings (emotional and sensori-motor), cardiovascular responses (heart rate, blood pressure, heart rate variability) and regional cerebral blood flow as determined with H(2)(15)O positron emission tomography. Psychobiological differences were found for the different DIS. Subjective and cardiovascular reactions revealed significant main and interactions effects. Regional cerebral blood flow data revealed different neural networks to be associated with different processing of the neutral and trauma-related memory script by NIS and TIS. Patients with DID encompass at least two different DIS. These identities involve different subjective reactions, cardiovascular responses and cerebral activation patterns to a trauma-related memory script.

  11. Brain functional integration: an epidemiologic study on stress-producing dissociative phenomena

    Science.gov (United States)

    Messina, Giovanni; Carotenuto, Marco; Maldonato, Nelson Mauro; Moretto, Enrico; Leone, Elena; De Luca, Vincenzo; Monda, Marcellino; Messina, Antonietta

    2018-01-01

    Dissociative phenomena are common among psychiatric patients; the presence of these symptoms can worsen the prognosis, increasing the severity of their clinical conditions and exposing them to increased risk of suicidal behavior. Personality disorders as long duration stressful experiences may support the development of dissociative phenomena. In 933 psychiatric outpatients consecutively recruited, presence of dissociative phenomena was identified with the Dissociative Experience Scale (DES). Dissociative phenomena were significantly more severe in the group of people with mental disorders and/or personality disorders. All psychopathologic traits detected with the symptom checklist-90-revised had a significant correlation with the total score on the DES. Using total DES score as the dependent variable, a linear regression model was constructed. Mental and personality disorders which were associated with greater severity of dissociative phenomena on analysis of variance were included as predictors; scores from the nine scales of symptom checklist-90-revised, significantly correlated to total DES score, were used as covariates. The model consisted of seven explanatory variables (four factors and three covariates) explaining 82% of variance. The four significant factors were the presence of borderline and narcissistic personality disorder, substance abuse disorders and psychotic disorders. Significant covariates were psychopathologic traits of anger, psychoticism and obsessiveness. This study, confirming Janet’s theory, explains that, mental disorders and psychopathologic experiences of patients can configure the chronic stress condition that produces functional damage to the adaptive executive system. The symptoms of dissociative depersonalization/derealization and dissociative amnesia can be explained, in large part, through their current and previous psychopathologic experiences. PMID:29296086

  12. A study of clinico-demographic profile of patients with dissociative disorder

    Directory of Open Access Journals (Sweden)

    SK Shah

    2013-09-01

    Full Text Available Objectives To study the clinical and socio demographic profile of patients with dissociative disorder and their comorbid mental illness. Materials and methods Fifty-one patients of dissociative disorder presenting to emergency and outpatient department of Psychiatry at College of Medical Sciences Teaching Hospital during the period from Jan to March 2012 were included. International statistical classification of diseases and related health problems tenth edition, diagnostic criteria for research (ICD-10, DCR was used. Results Out of 51 patients, the majority 24 (47.1%, were in the age group 15-29. However the age of presentation ranged from 9-45 years. The females were more, 44 (86.3% as compared to males 7 (13.7%. The majority of patients had low level of education with none of the patients having education above intermediate level. The majority of patients, 27(52.9% belonged to lower middle class. 49% of the patients presented with dissociative convulsions, 15.7% with dissociative motor disorders, 15.7% with dissociative stupor, 11.8% with dissociative anesthesia and sensory loss and 7.8% with trance and possession disorder. Depressive illness was found co-morbid with dissociative disorder in 33.3%, borderline personality disorder in 9.8% and histrionic personality disorder in 7.8%. There was history of immediate stressful events that supposedly precipitated the event in 76.5%. Conclusion Dissociative disorder mainly affects young female of lower socio-economic and educational status with history of immediate stressful life events precipitating the illness. Journal of College of Medical Sciences-Nepal, 2012, Vol-8, No-3, 30-35 DOI: http://dx.doi.org/10.3126/jcmsn.v8i3.8683

  13. Study of SI engine fueled with methanol vapor and dissociation gas based on exhaust heat dissociating methanol

    International Nuclear Information System (INIS)

    Fu, Jianqin; Deng, Banglin; Liu, Jingping; Wang, Linjun; Xu, Zhengxin; Yang, Jing; Shu, Gequn

    2014-01-01

    Highlights: • The full load power decreases successively from gasoline engine, methanol vapor engine to dissociated methanol engine. • Both power and thermal efficiency of dissociated methanol engine can be improved by boosting pressure. • The conversion efficiency of recovered exhaust gas energy is largely influenced by the BMEP. • At the same BMEP, dissociated methanol engine has higher thermal efficiency than methanol vapor engine and gasoline engine. - Abstract: To improve the fuel efficiency of internal combustion (IC) engine and also achieve the goal of direct usage of methanol fuel on IC engine, an approach of exhaust heat dissociating methanol was investigated, which is a kind of method for IC engine exhaust heat recovery (EHR). A bottom cycle system is coupled with the IC engine exhaust system, which uses the exhaust heat to evaporate and dissociate methanol in its catalytic cracker. The methanol dissociation gas (including methanol vapor) is used as the fuel for IC engine. This approach was applied to both naturally aspirated (NA) engine and turbocharged engine, and the engine performance parameters were predicted by the software GT-power under various kinds of operating conditions. The improvement to IC engine performance and the conversion efficiency of recovered exhaust gas energy can be evaluated by comparing the performances of IC engine fueled with various kinds of fuels (or their compositions). Results show that, from gasoline engine, methanol vapor engine to dissociated methanol engine, the full load power decreases successively in the entire speed area due to the declining of volumetric efficiency, while it is contrary in the thermal efficiency at the same brake mean effective pressure (BMEP) level because of the improving of fuel heating value. With the increase of BMEP, the conversion efficiency of recovered exhaust gas energy is promoted. All those results indicate that the approach of exhaust heat dissociating methanol has large

  14. The Distant Double Bond Determines the Fate of the Carboxylic Group in the Dissociative Photoionization of Oleic Acid.

    Science.gov (United States)

    Heringa, Maarten F; Slowik, Jay G; Goldmann, Maximilian; Signorell, Ruth; Hemberger, Patrick; Bodi, Andras

    2017-12-15

    The valence threshold photoionization of oleic acid has been studied using synchrotron VUV radiation and imaging photoelectron photoion coincidence (iPEPICO) spectroscopy. An oleic acid aerosol beam was impacted on a copper thermodesorber, heated to 130 °C, to evaporate the particles quantitatively. Upon threshold photoionization, oleic acid produces the intact parent ion first, followed by dehydration at higher energies. Starting at ca. 10 eV, a large number of fragment ions slowly rise suggesting several fragmentation coordinates with quasi-degenerate activation energies. However, water loss is the dominant low-energy dissociation channel, and it is shown to be closely related to the unsaturated carbon chain. In the lowest-barrier process, one of the four allylic hydrogen atoms is transferred to the carboxyl group to form the leaving water molecule and a cyclic ketone fragment ion. A statistical model to analyze the breakdown diagram and measured rate constants yields a 0 K appearance energy of 9.77 eV, which can be compared with the density functional theory result of 9.19 eV. Alternative H-transfer steps yielding a terminal C=O group are ruled out based on energetics and kinetics arguments. Some of the previous photoionization mass spectrometric studies also reported 2 amu and 26 amu loss fragment ions, corresponding to hydrogen and acetylene loss. We could not identify such peaks in the mass spectrum of oleic acid. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. A study of the stressor, family environment and family burden in dissociative (conversion disorder patients

    Directory of Open Access Journals (Sweden)

    Kamal K Verma

    2017-01-01

    Full Text Available Background: Dissociative disorder is a stress-related disorder usually present in adolescent and younger age group. It is also accompanied with significant impairment in activity of daily living and family relationship. Family environment plays important role in initiation and maintenance of symptoms and this put significant burden on family. Aim and Objective: To study presence of stressor, family environment, and assessment of family burden in dissociative disorder patients. Material and Method: This was a cross-sectional observational study in which 100 dissociatives disorder patients were included after fulfilling inclusion criteria from both inpatients and outpatient department of psychiatry. Results: In our study major part of the sample were women 60 (60%, among them most of were housewife and educated up to primary school. According to a stressor, 63 (63% patients had family stress/problem and out of them, 35 (58.4 were women. Seventy-four (74% patients had dissociative convulsion and out of them, 45 (75% were women. The dissociative disorder patients cause a considerable degree of burden over other family members in both men and women. There is a significant difference found in the family environment in term of personal growth dimension, relationship dimension in both men and women. Conclusion: Present study concludes that dissociative disorder patients cause a considerable degree of burden over other family members in term of leisure, physical, mental, financial, and routines family interrelationship domains. The family environment in term of personal growth dimension, relationship dimension has a casual effect on symptoms of dissociative disorder patients.

  16. Double dissociation of spike timing-dependent potentiation and depression by subunit-preferring NMDA receptor antagonists in mouse barrel cortex.

    Science.gov (United States)

    Banerjee, Abhishek; Meredith, Rhiannon M; Rodríguez-Moreno, Antonio; Mierau, Susanna B; Auberson, Yves P; Paulsen, Ole

    2009-12-01

    Spike timing-dependent plasticity (STDP) is a strong candidate for an N-methyl-D-aspartate (NMDA) receptor-dependent form of synaptic plasticity that could underlie the development of receptive field properties in sensory neocortices. Whilst induction of timing-dependent long-term potentiation (t-LTP) requires postsynaptic NMDA receptors, timing-dependent long-term depression (t-LTD) requires the activation of presynaptic NMDA receptors at layer 4-to-layer 2/3 synapses in barrel cortex. Here we investigated the developmental profile of t-LTD at layer 4-to-layer 2/3 synapses of mouse barrel cortex and studied their NMDA receptor subunit dependence. Timing-dependent LTD emerged in the first postnatal week, was present during the second week and disappeared in the adult, whereas t-LTP persisted in adulthood. An antagonist at GluN2C/D subunit-containing NMDA receptors blocked t-LTD but not t-LTP. Conversely, a GluN2A subunit-preferring antagonist blocked t-LTP but not t-LTD. The GluN2C/D subunit requirement for t-LTD appears to be synapse specific, as GluN2C/D antagonists did not block t-LTD at horizontal cross-columnar layer 2/3-to-layer 2/3 synapses, which was blocked by a GluN2B antagonist instead. These data demonstrate an NMDA receptor subunit-dependent double dissociation of t-LTD and t-LTP mechanisms at layer 4-to-layer 2/3 synapses, and suggest that t-LTD is mediated by distinct molecular mechanisms at different synapses on the same postsynaptic neuron.

  17. First-principles study of H2 adsorption and dissociation on Zr(0 0 0 1)

    International Nuclear Information System (INIS)

    Zhang Peng; Wang Shuangxi; Zhao Jian; He Chaohui; Zhang Ping

    2011-01-01

    Highlights: → The stability of the equilibrium adsorption states is determined after the geometry optimization. → The origin of the stable chemisorbed state is analyzed by the electronic structure and charge redistribution calculation. → The dissociation energetics of H2 are investigated in details by the PES and CINEB calculation. - Abstract: The adsorption and dissociation of H 2 molecules on the Zr(0 0 0 1) surface are systematically investigated by using density functional theory within the generalized gradient approximation and a supercell approach. After geometry optimization, the most stable equilibrium adsorption state is found to be along the top-y entrance. By calculating the adiabatic potential energy surface, the chemisorbed molecular adsorption states are also identified to be along the parallel channel at the top site. The electronic properties of the stable chemisorbed molecular state are analyzed, which show that the interaction between the molecule and substrate is of covalent characteristic with a sizeable charge redistribution. On the other hand, the hcp site is turned out to be the most stable equilibrium adsorption site for hydrogen atom on Zr(0 0 0 1) surface after the dissociation of H 2 . The dissociation energetics of H 2 are studied by calculating the potential energy surface and the minimum energy path of the transition state is determined by using the climb image nudged elastic band method, wherein the fcc-y channel is found to be most stable and favorable for dissociative adsorption of H 2 among the five possible dissociative paths. Remarkably, we find that the adiabatic dissociation process of H 2 is an activated type but with a small energy barrier, which is well consistent with the macroscopic phenomenon that the zirconium metal is easily hydrogenated.

  18. Isotope exchange study of the dissociation of metal-humic complexes

    International Nuclear Information System (INIS)

    Mizera, J.; Jansova, A.; Hvozdova, I.; Benes, P.

    2002-01-01

    Prediction of the migration of toxic metals and radionuclides in the environment requires knowledge of equilibrium and kinetic parameters characterising their interaction with humic substance (HS). In this work, isotope exchange of Eu and Co in the systems containing HS has been used to study dissociation of the cations from their complexes with HS under quasi-stationary conditions. In the experimental arrangement of the so-called diaphragm method, a dialysis membrane divides two compartments containing solutions of metal and HS, identical in both half-cells but for radiolabeling ( 152 Eu and 60 Co) applied only in one cell. The membrane is permeable for free metal cation but not for the metal-HS complex. The slow dissociation of metal cation from HS is reflected by retardation (compared to a reference system in the absence of HS) of the rate of the isotope exchange between the two compartments. However, only an apparent dissociation rate can be observed, as detection of fast dissociation is limited by the rate of diffusion of dissociated cations through membrane and by their recombination with available binding sites of HS. The rate of isotope exchange of Eu and Co in the systems with HS (Aldrich sodium humate, soil humic and fulvic acid) was monitored as function of pH (4 and 6), ionic strength (0.01 and 0.1 M), and the degree of HS loading with metal ([M] 0 = 10 -7 - 2x10 -5 M at 10 mg/L HS). For Co, the rate of 60 Co 2+ diffusion through the membrane showed up to control the rate of the isotope exchange indicating that the Co-HS dissociation is too fast to be followed by the diaphragm method, and that the abundance of non-complexed Co is not negligible. The apparent rate of Eu-HS dissociation was found to be enhanced by decreasing pH value, increasing ionic strength, and increasing metal loading (i.e., metal/HS ratio). For interpretation of the experimental kinetic data, a discrete 2-component model (bi-exponential decay function) was applied. Based on

  19. Brain functional integration: an epidemiologic study on stress-producing dissociative phenomena

    Directory of Open Access Journals (Sweden)

    Sperandeo R

    2017-12-01

    Full Text Available Raffaele Sperandeo,1,2,* Vincenzo Monda,3,* Giovanni Messina,4 Marco Carotenuto,5 Nelson Mauro Maldonato,1,2 Enrico Moretto,1,2 Elena Leone,1,2 Vincenzo De Luca,6 Marcellino Monda,3 Antonietta Messina3 1Department of Human Sciences, Università Della, Basilicata, 2School of Integrated Gestaltic Psychotherapy, Torre Annunziata, 3Department of Experimental Medicine, Section of Human Physiology and Unit of Dietetic and Sport Medicine, Università degli Studi della Campania “Luigi Vanvitelli”, Naples, 4Department of Clinical and Experimental Medicine, University of Foggia, Foggia, 5Department of Mental Health, Physical and Preventive Medicine, Clinic of Child and Adolescent Neuropsychiatry, Università degli Studi della Campania “Luigi Vanvitelli”, Naples, Italy; 6Department of Psychiatry, University of Toronto, Toronto, Canada *These authors contributed equally to this work Abstract: Dissociative phenomena are common among psychiatric patients; the presence of these symptoms can worsen the prognosis, increasing the severity of their clinical conditions and exposing them to increased risk of suicidal behavior. Personality disorders as long duration stressful experiences may support the development of dissociative phenomena. In 933 psychiatric outpatients consecutively recruited, presence of dissociative phenomena was identified with the Dissociative Experience Scale (DES. Dissociative phenomena were significantly more severe in the group of people with mental disorders and/or personality disorders. All psychopathologic traits detected with the symptom checklist-90-revised had a significant correlation with the total score on the DES. Using total DES score as the dependent variable, a linear regression model was constructed. Mental and personality disorders which were associated with greater severity of dissociative phenomena on analysis of variance were included as predictors; scores from the nine scales of symptom checklist-90-revised

  20. Episodic feeling-of-knowing accuracy and cued recall in the elderly: evidence for double dissociation involving executive functioning and processing speed.

    Science.gov (United States)

    Perrotin, Audrey; Isingrini, Michel; Souchay, Céline; Clarys, David; Taconnat, Laurence

    2006-05-01

    This research investigated adult age differences in a metamemory monitoring task-episodic feeling-of-knowing (FOK) and in an episodic memory task-cued recall. Executive functioning and processing speed were examined as mediators of these age differences. Young and elderly adults were administered an episodic FOK task, a cued recall task, executive tests and speed tests. Age-related decline was observed on all the measures. Correlation analyses revealed a pattern of double dissociation which indicates a specific relationship between executive score and FOK accuracy, and between speed score and cued recall. When executive functioning and processing speed were evaluated concurrently on FOK and cued recall variables, hierarchical regression analyses showed that executive score was a better mediator of age-related variance in FOK, and that speed score was the better mediator of age-related variance in cued recall.

  1. Tracking Potentiating States of Dissociation: An Intensive Clinical Case Study of Sleep, Daydreaming, Mood, and Depersonalization/Derealization

    Science.gov (United States)

    Poerio, Giulia L.; Kellett, Stephen; Totterdell, Peter

    2016-01-01

    This study examined in real time the role of sleep and daydreaming as potentiating states for subsequent dissociation in depersonalization/derealization disorder (DDD). Research and theory suggests that dissociation may be exacerbated and maintained by a labile sleep-wake cycle in which “dream-like” mentation intrudes into waking life and fuels dissociative symptoms. We explore and extend this idea by examining the state of daydreaming in dissociation. Daydreaming is a state of consciousness between dreaming and waking cognition that involves stimulus-independent and task-unrelated mentation. We report the results of a unique intensive N = 1 study with an individual meeting diagnostic criteria for DDD. Using experience-sampling methodology, the participant rated (six times daily for 40 days) current daydreaming, mood, and dissociative symptoms. At the start of each day sleep quality and duration was also rated. Daydreaming was reported on 45% of occasions and significantly predicted greater dissociation, in particular when daydreams were repetitive and negative (but not fanciful) in content. These relationships were mediated by feelings of depression and anxiety. Sleep quality but not duration was a negative predictor of daily dissociation and also negatively predicted depression but not anxiety. Findings offer initial evidence that the occurrence and content of daydreams may act as potentiating states for heightened, in the moment, dissociation. The treatment implications of targeting sleep and daydreaming for dissociative disorders are discussed. PMID:27582722

  2. Tracking potentiating states of dissociation: An intensive clinical case study of sleep, daydreaming, mood, and depersonalization/derealization

    Directory of Open Access Journals (Sweden)

    Giulia Lara Poerio

    2016-08-01

    Full Text Available This study examined in real time the role of sleep and daydreaming as potentiating states for subsequent dissociation in depersonalization/derealization disorder (DDD. Research and theory suggests that dissociation may be exacerbated and maintained by a labile sleep-wake cycle in which ‘dream-like’ mentation intrudes into waking life and fuels dissociative symptoms. We explore and extend this idea by examining the state of daydreaming in dissociation. Daydreaming is a state of consciousness between dreaming and waking cognition that involves stimulus-independent and task-unrelated mentation. We report the results of a unique intensive N=1 study with an individual meeting diagnostic criteria for DDD. Using experience-sampling methodology, the participant rated (six times daily for 40 days current daydreaming, mood, and dissociative symptoms. At the start of each day sleep quality and duration was also rated. Daydreaming was reported on 45% of occasions and significantly predicted greater dissociation, in particular when daydreams were repetitive and negative (but not fanciful in content. These relationships were mediated by feelings of depression and anxiety. Sleep quality but not duration was a negative predictor of daily dissociation and also negatively predicted depression but not anxiety. Findings offer initial evidence that the occurrence and content of daydreams may act as potentiating states for heightened, in the moment, dissociation. The treatment implications of targeting sleep and daydreaming for dissociative disorders are discussed.

  3. Peritraumatic dissociation and posttraumatic stress after pregnancy loss: A prospective study.

    NARCIS (Netherlands)

    Engelhard, I.M.; van den Hout, M.; Kindt, M.; Arntz, A.; Schouten, E.

    2003-01-01

    This study examined (1) predictors for peritraumatic dissociation, (2) its relations with acute and chronic symptoms of posttraumatic stress disorder (PTSD), and (3) pathways regarding these relations in response to pregnancy loss. In early pregnancy, about 1,370 women volunteers completed

  4. Dissociation Pathways of Benzylpyridinium "Thermometer" Ions Depend on the Activation Regime: An IRMPD Spectroscopy Study

    NARCIS (Netherlands)

    Morsa, D.; Gabelica, V.; Rosu, F.; Oomens, J.; De Pauw, E.

    2014-01-01

    The dissociation of benzylpyridinium "thermometer" ions is widely used to calibrate the internal energy of ions produced in mass spectrometry. The fragmentation mechanism is usually believed to yield a benzylium cation, although recent studies suggest the possibility of a rearrangement leading to

  5. Opposite brain emotion-regulation patterns in identity states of dissociative identity disorder : A PET study and neurobiological model

    NARCIS (Netherlands)

    Reinders, Antje A. T. S.; Willemsen, Antoon T. M.; den Boer, Johan A.; Vos, Herry P. J.; Veltman, Dick J.; Loewenstein, Richard J.

    2014-01-01

    Imaging studies in posttraumatic stress disorder (PTSD) have shown differing neural network patterns between hypo-aroused/dissociative and hyper-aroused subtypes. Since dissociative identity disorder (DID) involves different emotional states, this study tests whether DID fits aspects of the

  6. Rapidly dissociated autologous meniscus tissue enhances meniscus healing: An in vitro study.

    Science.gov (United States)

    Numpaisal, Piya-On; Rothrauff, Benjamin B; Gottardi, Riccardo; Chien, Chung-Liang; Tuan, Rocky S

    Treatment of meniscus tears is a persistent challenge in orthopedics. Although cell therapies have shown promise in promoting fibrocartilage formation in in vitro and preclinical studies, clinical application has been limited by the paucity of autologous tissue and the need for ex vivo cell expansion. Rapid dissociation of the free edges of the anterior and posterior meniscus with subsequent implantation in a meniscus lesion may overcome these limitations. The purpose of this study was to explore the effect of rapidly dissociated meniscus tissue in enhancing neotissue formation in a radial meniscus tear, as simulated in an in vitro explant model. All experiments in this study, performed at minimum with biological triplicates, utilized meniscal tissues from hind limbs of young cows. The effect of varying collagenase concentration (0.1%, 0.2% and 0.5% w/v) and treatment duration (overnight and 30 minutes) on meniscus cell viability, organization of the extracellular matrix (ECM), and gene expression was assessed through a cell metabolism assay, microscopic examination, and quantitative real-time reverse transcription polymerase chain reaction analysis, respectively. Thereafter, an explant model of a radial meniscus tear was used to evaluate the effect of a fibrin gel seeded with one of the following: (1) fibrin alone, (2) isolated and passaged (P2) meniscus cells, (3) overnight digested tissue, and (4) rapidly dissociated tissue. The quality of in vitro healing was determined through histological analysis and derivation of an adhesion index. Rapid dissociation in 0.2% collagenase yielded cells with higher levels of metabolism than either 0.1% or 0.5% collagenase. When seeded in a three-dimensional fibrin hydrogel, both overnight digested and rapidly dissociated cells expressed greater levels of collagens type I and II than P2 meniscal cells at 1 week. At 4 and 8 weeks, collagen type II expression remained elevated only in the rapid dissociation group. Histological

  7. The effects of dissociation on information processing for analogue trauma and neutral stimuli: a laboratory study.

    Science.gov (United States)

    Olsen, Shira A; Beck, J Gayle

    2012-01-01

    This study investigated the effects of high and low levels of dissociation on information processing for analogue trauma and neutral stimuli. Fifty-four undergraduate females who reported high and low levels of trait dissociation were presented with two films, one depicting traumatic events, the other containing neutral material. Participants completed a divided attention task (yielding a proxy measure of attention), as well as explicit memory (free-recall) and implicit memory (word-stem completion) tasks for both films. Results indicated that the high DES group showed less attention and had poorer recall for the analogue trauma stimuli, relative to the neutral stimuli and the low DES group. These findings suggest that high levels of trait dissociation are associated with reductions in attention and memory for analogue trauma stimuli, relative to neutral stimuli and relative to low trait dissociation. Implications for the role of cognitive factors in the etiology of negative post-trauma responses are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Study of the Dissociative Processes in O_2 Discharges. Development of an Atomic Oxygen Beam Source

    International Nuclear Information System (INIS)

    Pagnon, Daniel

    1992-01-01

    The first part of this work is devoted to the study of dissociative processes in an oxygen glow discharge at low pressure (0,1-5 Torr, 1-80 mA). The kinetics of oxygen atoms has been determined supported by the measurements of atomic concentrations by VUV absorption spectroscopy and actinometry. The reaction coefficients for dissociative excitation and direct excitation of oxygen atoms have been calculated using the cross sections of the literature and a previously calculated EEDF. It has been demonstrated that dissociative excitation is negligible in respect with direct excitation for dissociation rates smaller than 2,5 %. An upper limit of 20 % for dissociative rates is observed. This limit has been explained by the increase of the atomic recombination at the discharge wall with increasing wall temperature. Using all these results, we have designed and optimized a source of oxygen atoms which has then been adapted on a MBE device. The spatial distribution of the atomic density has been measured in molecular jet by laser induced fluorescence (LIF) and Resonant Multi-Photon Ionization (RMPI). A stimulated emission has been evidenced and the coefficient for this process evaluated. A model for the effusion of atoms has been developed from which the flow of atoms on the sample can be predicted. This source has already been used in industrial MBE devices for in-situ oxidation of copper films, superconductors, and substrates for VLSI high speed applications. The methodology of this work and the diagnostics developed can be applied to other kinds of discharges, of other molecular gases, to design sources of atoms for the treatment of large area samples. (author) [fr

  9. The dissociative post-traumatic stress disorder (PTSD) subtype: A treatment outcome cohort study in veterans with PTSD.

    Science.gov (United States)

    Haagen, Joris F G; van Rijn, Allison; Knipscheer, Jeroen W; van der Aa, Niels; Kleber, Rolf J

    2018-06-01

    Dissociation is a prevalent phenomenon among veterans with post-traumatic stress disorder (PTSD) that may interfere with the effectiveness of treatment. This study aimed to replicate findings of a dissociative PTSD subtype, to identify corresponding patterns in coping style, symptom type, and symptom severity, and to investigate its impact on post-traumatic symptom improvement. Latent profile analysis (LPA) was applied to baseline data from 330 predominantly (97%) male treatment-seeking veterans (mean age 39.5 years) with a probable PTSD. Multinomial logistic models were used to identify predictors of dissociative PTSD. Eighty veterans with PTSD that commenced with psychotherapy were invited for a follow-up measure after 6 months. The majority (n = 64, 80% response rate) completed the follow-up measure. Changes in post-traumatic stress between baseline and follow-up were explored as a continuous distal outcome. Latent profile analysis revealed four distinct patient profiles: 'low' (12.9%), 'moderate' (33.2%), 'severe' (45.1%), and 'dissociative' (8.8%) PTSD. The dissociative PTSD profile was characterized by more severe pathology levels, though not post-traumatic reactions symptom severity. Veterans with dissociative PTSD benefitted equally from PTSD treatment as veterans with non-dissociative PTSD with similar symptom severity. Within a sample of veterans with PTSD, a subsample of severely dissociative veterans was identified, characterized by elevated severity levels on pathology dimensions. The dissociative PTSD subtype did not negatively impact PTSD treatment. The present findings confirmed the existence of a distinct subgroup veterans that fit the description of dissociative PTSD. Patients with dissociative PTSD subtype symptoms uniquely differed from patients with non-dissociative PTSD in the severity of several psychopathology dimensions. Dissociative and non-dissociative PTSD patients with similar post-traumatic severity levels showed similar levels of

  10. Dissociable effects of motivation and expectancy on conflict processing: an fMRI study.

    Science.gov (United States)

    Soutschek, Alexander; Stelzel, Christine; Paschke, Lena; Walter, Henrik; Schubert, Torsten

    2015-02-01

    Previous studies suggest that both motivation and task difficulty expectations activate brain regions associated with cognitive control. However, it remains an open question whether motivational and cognitive determinants of control have similar or dissociable impacts on conflict processing on a neural level. The current study tested the effects of motivation and conflict expectancy on activity in regions related to processing of the target and the distractor information. Participants performed a picture-word interference task in which we manipulated the size of performance-dependent monetary rewards (level of motivation) and the ratio of congruent to incongruent trials within a block (level of conflict expectancy). Our results suggest that motivation improves conflict processing by facilitating task-relevant stimulus processing and task difficulty expectations mainly modulate the processing of distractor information. We conclude that motivation and conflict expectancy engage dissociable control strategies during conflict resolution.

  11. Dynamics of gas-phase transient species studied by dissociative photodetachment of molecular anions

    OpenAIRE

    Lu, Zhou

    2007-01-01

    Gas-phase transient species, such as the CH₃CO₂ and HOCO free radicals, play important roles in combustion and environment chemistry. In this thesis work, the dynamics of these two radicals were studied by dissociative photodetachment (DPD) of the negative ions, CH₃CO₂-С and HOCO⁻, respectively. The experiments were carried out with a fast-ion-beam photoelectron-photofragment coincidence (PPC) spectrometer. Mass-selected molecular anions in a fast ion beam were intercepted by a linearly polar...

  12. 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.

  13. Density function theory study of the adsorption and dissociation of carbon monoxide on tungsten nanoparticles.

    Science.gov (United States)

    Weng, Meng-Hsiung; Ju, Shin-Pon; Chen, Hsin-Tsung; Chen, Hui-Lung; Lu, Jian-Ming; Lin, Ken-Huang; Lin, Jenn-Sen; Hsieh, Jin-Yuan; Yang, Hsi-Wen

    2013-02-01

    The adsorption and dissociation properties of carbon monoxide (CO) molecule on tungsten W(n) (n = 10-15) nanoparticles have been investigated by density-functional theory (DFT) calculations. The lowest-energy structures for W(n) (n = 10-15) nanoparticles are found by the basin-hopping method and big-bang method with the modified tight-binding many-body potential. We calculated the corresponding adsorption energies, C-O bond lengths and dissociation barriers for adsorption of CO on nanoparticles. The electronic properties of CO on nanoparticles are studied by the analysis of density of state and charge density. The characteristic of CO on W(n) nanoparticles are also compared with that of W bulk.

  14. Distinct modulatory effects of satiety and sibutramine on brain responses to food images in humans: a double dissociation across hypothalamus, amygdala and ventral striatum

    Science.gov (United States)

    Fletcher, PC; Napolitano, A; Skeggs, A; Miller, SR; Delafont, B; Cambridge, VC; de Wit, S; Nathan, PJ; Brooke, A; O’Rahilly, S; Farooqi, IS; Bullmore, ET

    2012-01-01

    We used fMRI to explore brain responses to food images in overweight humans, examining independently the impact of a pre-scan meal (“satiety”) and the anti-obesity drug sibutramine, a serotonin and noradrenaline reuptake inhibitor. We identified significantly different responses to these manipulations in amygdala, hypothalamus and ventral striatum. Each region was specifically responsive to high calorie compared to low calorie food images. However, the ventral striatal response was attenuated by satiety (but unaffected by sibutramine) while the hypothalamic and amygdala responses were attenuated by drug but unaffected by satiety. Direct assessment of regional interactions confirmed the significance of this double dissociation. We explored the regional responses in greater detail by determining whether they were predictive of eating behaviour and weight change. We observed that across the different regions, the individual-specific magnitude of drug- and satiety-induced modulation was associated with both variables: the sibutramine-induced modulation of the hypothalamic response was correlated with the drug’s impact on both weight and subsequently-measured ad libitum eating. The satiety-induced modulation of striatal response also correlated with subsequent ad lib eating. These results suggest that hypothalamus and amygdala have roles in the control of food intake that are distinct from those of ventral striatum. Furthermore, they support a regionally-specific effect on brain function through which sibutramine exerts its clinical effect. PMID:20980590

  15. Time resolved studies of H{sub 2}{sup +} dissociation with phase-stabilized laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Bettina

    2010-06-23

    In the course of this thesis, experimental studies on the dissociation of H{sub 2}{sup +}(H{sub 2}{sup +}{yields}p+H) in ultrashort laser pulses with a stabilized carrier-envelope phase (CEP) were carried out. In single-pulse measurements, the ability to control the emission direction of low energetic protons, i.e. the localization of the bound electron at one of the nuclei after dissociation, by the CEP was demonstrated. The coincident detection of the emitted protons and electrons and the measurement of their three-dimensional momentum vectors with a reaction microscope allowed to clarify the localization mechanism. Further control was achieved by a pump-control scheme with two timedelayed CEP-stabilized laser pulses. Here the neutral H{sub 2} molecule was ionized in the first pulse and dissociation was induced by the second pulse. Electron localization was shown to depend on the properties of the bound nuclear wave packet in H{sub 2}{sup +} at the time the control pulse is applied, demonstrating the ability to use the shape and dynamics of the nuclear wave packet as control parameters. Wave packet simulations were performed reproducing qualitatively the experimental results of the single and the two-pulse measurements. For both control schemes, intuitive models are presented, which qualitatively explain the main features of the obtained results. (orig.)

  16. Ab Initio Study of Hydration and Proton Dissociation in Ionomer Membranes

    International Nuclear Information System (INIS)

    Idupulapati, Nagesh B.; Devanathan, Ramaswami; Dupuis, Michel

    2010-01-01

    We present a comparative study of proton dissociation in various functional acidic units that are promising candidates as building blocks for polymeric electrolyte membranes. Minimum energy structures for four acidic moieties with clusters of 1-6 water molecules were determined using density functional theory at the B3LYP/6-311G** level starting from chemically rational initial configurations. The perfluoro sulfonyl imide acid group (CF3CF2SO2NHSO2CF3) was observed to be the strongest acid, due to the substantial electron withdrawing effect of both fluorocarbon groups. The hydrophilic functional group (CH3OC6H3OCH3C6H4SO3H) of sulfonated polyetherether ketone (SPEEK) membrane was found to be the strongest base with the acidic proton dissociation requiring the addition of six water molecules and the hydrated proton being more tightly bound to the conjugate base. Even though both perfluoro sulfonyl imides and sulfonic acids (hydrophilic functional groups for sulfonyl imide and Nafion ionomers respectively) required only three water molecules to exhibit spontaneous proton dissociation, the largest possible solvent-separated hydronium ion was attained only for the sulfonyl imide moiety. These results provide a scientific basis for understanding the improved conductivity of perfluorinated sulfonyl imide-based membranes relative to that of the widely-used Nafion membrane.

  17. A theoretical study of CH4 dissociation on pure and gold-alloyed Ni(111) surfaces

    DEFF Research Database (Denmark)

    Kratzer, P.; Hammer, Bjørk; Nørskov, Jens Kehlet

    1996-01-01

    We present a density functional theory study of the first step of CH4 adsorption on the Ni(111) surface, dissociation into adsorbed CH3 and H. The rupture of the C-H bond occurs preferentially on top of a Ni atom, with a dissociation barrier of about 100 kJ/mol (including zero point corrections......). The transition state involves considerable internal excitation of the molecule. The active C-H bond is both stretched to 1.6 Angstrom and tilted relative to the methyl group. A normal mode analysis shows that the reaction coordinate is mainly a C-H stretch, while the orientation of the C-H bond relative...... to the surface is responsible for the highest real mode. Alloying the surface with gold also affects the reactivity of the Ni atoms on adjacent surface sites. The dissociation barrier is increased by 16 and 38 kJ/mol for a Ni atom with one or two gold neighbors, respectively. We attribute these changes...

  18. Pulsed IR Heating Studies of Single-Molecule DNA Duplex Dissociation Kinetics and Thermodynamics

    Science.gov (United States)

    Holmstrom, Erik D.; Dupuis, Nicholas F.; Nesbitt, David J.

    2014-01-01

    Single-molecule fluorescence spectroscopy is a powerful technique that makes it possible to observe the conformational dynamics associated with biomolecular processes. The addition of precise temperature control to these experiments can yield valuable thermodynamic information about equilibrium and kinetic rate constants. To accomplish this, we have developed a microscopy technique based on infrared laser overtone/combination band absorption to heat small (≈10−11 liter) volumes of water. Detailed experimental characterization of this technique reveals three major advantages over conventional stage heating methods: 1), a larger range of steady-state temperatures (20–100°C); 2), substantially superior spatial (≤20 μm) control; and 3), substantially superior temporal (≈1 ms) control. The flexibility and breadth of this spatial and temporally resolved laser-heating approach is demonstrated in single-molecule fluorescence assays designed to probe the dissociation of a 21 bp DNA duplex. These studies are used to support a kinetic model based on nucleic acid end fraying that describes dissociation for both short (10 bp) DNA duplexes. These measurements have been extended to explore temperature-dependent kinetics for the 21 bp construct, which permit determination of single-molecule activation enthalpies and entropies for DNA duplex dissociation. PMID:24411254

  19. Time resolved studies of H2+ dissociation with phase-stabilized laser pulses

    International Nuclear Information System (INIS)

    Fischer, Bettina

    2010-01-01

    In the course of this thesis, experimental studies on the dissociation of H 2 + (H 2 + →p+H) in ultrashort laser pulses with a stabilized carrier-envelope phase (CEP) were carried out. In single-pulse measurements, the ability to control the emission direction of low energetic protons, i.e. the localization of the bound electron at one of the nuclei after dissociation, by the CEP was demonstrated. The coincident detection of the emitted protons and electrons and the measurement of their three-dimensional momentum vectors with a reaction microscope allowed to clarify the localization mechanism. Further control was achieved by a pump-control scheme with two timedelayed CEP-stabilized laser pulses. Here the neutral H 2 molecule was ionized in the first pulse and dissociation was induced by the second pulse. Electron localization was shown to depend on the properties of the bound nuclear wave packet in H 2 + at the time the control pulse is applied, demonstrating the ability to use the shape and dynamics of the nuclear wave packet as control parameters. Wave packet simulations were performed reproducing qualitatively the experimental results of the single and the two-pulse measurements. For both control schemes, intuitive models are presented, which qualitatively explain the main features of the obtained results. (orig.)

  20. Dissociation in small molecules

    International Nuclear Information System (INIS)

    Dehmer, P.M.

    1982-01-01

    The study of molecular dissociation processes is one of the most interesting areas of modern spectroscopy owing to the challenges presented bt even the simplest of diatomic molecules. This paper reviews the commonly used descriptions of molecular dissociation processes for diatomic molecules, the selection rules for predissociation, and a few of the principles to be remembered when one is forced to speculate about dissociation mechanisms in a new molecule. Some of these points will be illustrated by the example of dissociative ionization in O 2

  1. Time-dependent wave-packet study of the direct low-energy dissociative recombination of HD+

    International Nuclear Information System (INIS)

    Orel, A. E.

    2000-01-01

    Wave-packet methods involving the numerical solution of the time-dependent Schroedinger equation have been used with great success in the calculation of cross sections for dissociative recombination of molecular ions by electron impact in the high energy region where the ''boomerang'' model [L. Dube and A. Herzenberg, Phys. Rev. A 11, 1314 (1975)] is valid. We extend this method to study low-energy dissociative recombination where this approximation is no longer appropriate. We apply the method to the ''direct'' low-energy dissociative recombination of HD + . Our results are in excellent agreement with calculations using the multichannel quantum defect method. (c) 2000 The American Physical Society

  2. Out of mind - out of sight : studies on clinical and psychophysiological characteristics of dissociative identity disorder

    OpenAIRE

    Dale, Karl Yngvar

    2008-01-01

    Dissociative identity disorder (DID; APA, 1994), previously labeled Multiple personality (APA, 1980) and Multiple Personality Disorder (APA, 1987), has good diagnostic validity (Gleaves, May, & Cardeña, 2001) and is supported by taxometric research, whereby two types of dissociation have been identified: Pathological dissociation, whose features are consistent with DID, and nonpathological dissociation (Waller, Putnam, & Carlson, 1996). On these grounds, we aimed to contribute to a further...

  3. Experimental study of the dissociation of 100-600 KeV hydrogen cluster ions in an argon gas target

    International Nuclear Information System (INIS)

    Chevallier, M.; Clouvas, A.; Frischkorn, H.J.; Gaillard, M.J.; Poizat, J.C.; Remillieux, J.

    1985-09-01

    We have studied the break-up of accelerated hydrogen cluster ions passing through an argon gas target. The absolute dissociation cross section has been measured for a wide variety of H n + (odd masses only) cluster ions, with n between 5 and 23 and with projectile velocities ranging from 1.5 to 5 x 10 8 cm/s. We discuss the dissociation processes and the dependence of their cross-sections upon the cluster mass and velocity

  4. Visible luminescence studies in the infrared multiphoton dissociation of 1,2-dichloro-1,1-difluoroethane

    Science.gov (United States)

    Pushpa, K. K.; Kumar, Awadesh; Naik, P. D.; Annaji Rao, K.; Parthasarathy, V.; Sarkar, S. K.; Mittal, J. P.

    1997-11-01

    A strong visible luminescence was observed in the CO 2 laser induced infrared multiphoton dissociation of 1,2-dichloro-1,1-difluoroethane. The emission observed between 350-750 nm is attributed to electronically excited carbene CF 2ClCH. The temporal profile of this luminescence was studied as a function of laser pulse duration, pulse energy, excitation frequency and substrate pressure. A suitable dissociation mechanism is presented considering various channels of IRMPD of this molecule.

  5. Catalytic methanol dissociation

    International Nuclear Information System (INIS)

    Alcinikov, Y.; Fainberg, V.; Garbar, A.; Gutman, M.; Hetsroni, G.; Shindler, Y.; Tatrtakovsky, L.; Zvirin, Y.

    1998-01-01

    Results of the methanol dissociation study on copper/potassium catalyst with alumina support at various temperatures are presented. The following gaseous and liquid products at. The catalytic methanol dissociation is obtained: hydrogen, carbon monoxide, carbon dioxide, methane, and dimethyl ether. Formation rates of these products are discussed. Activation energies of corresponding reactions are calculated

  6. Support for distinct subcomponents of spatial working memory: a double dissociation between spatial-simultaneous and spatial-sequential performance in unilateral neglect.

    Science.gov (United States)

    Wansard, Murielle; Bartolomeo, Paolo; Bastin, Christine; Segovia, Fermín; Gillet, Sophie; Duret, Christophe; Meulemans, Thierry

    2015-01-01

    Over the last decade, many studies have demonstrated that visuospatial working memory (VSWM) can be divided into separate subsystems dedicated to the retention of visual patterns and their serial order. Impaired VSWM has been suggested to exacerbate left visual neglect in right-brain-damaged individuals. The aim of this study was to investigate the segregation between spatial-sequential and spatial-simultaneous working memory in individuals with neglect. We demonstrated that patterns of results on these VSWM tasks can be dissociated. Spatial-simultaneous and sequential aspects of VSWM can be selectively impaired in unilateral neglect. Our results support the hypothesis of multiple VSWM subsystems, which should be taken into account to better understand neglect-related deficits.

  7. An ion cooling and state characterization apparatus for studies of molecular ion dissociative interactions

    International Nuclear Information System (INIS)

    Deng, Shihu; Vane, C R; Bannister, M E; Havener, C C; Meyer, F W; Krause, H F; Hettich, R L; Goeringer, D E; Van Berkel, G J

    2009-01-01

    An experimental capability is being developed at the Oak Ridge National Laboratory Multi-Charged Ion Research Facility (ORNL MIRF) to enable stored cooling and state characterization of molecular ions of essentially any mass. Ions selected from a variety of available sources are injected from the side into a 1.5 meter long electrostatic mirror trap, where excited internal states are cooled by radiative cooling. An electron beam target located near the middle of the ion-trap region, coupled with neutral fragment imaging detector systems at each end of the trap, permits state-specific studies of electron-molecular ion dissociation.

  8. Study on the dissociative recombination of HeH+ by multi-channel quantum defect theory

    Directory of Open Access Journals (Sweden)

    Takagi Hidekazu

    2015-01-01

    Full Text Available The dissociative recombination of HeH+ is studied using multi-channel quantum defect theory. We investigated how the partial waves of incident electrons affect the DR cross section. The DR cross section depends on the position of the center of partial wave expansion for the adiabatic S-matrix of electron scattering. When the Rydberg states correlate with the Rydberg states of the hydrogen atom at large internuclear distances, the center should be on the hydrogen atom for a better convergence of the expansion.

  9. Fact or Factitious? A Psychobiological Study of Authentic and Simulated Dissociative Identity States

    Science.gov (United States)

    Simone Reinders, A. A. T.; Willemsen, Antoon T. M.; Vos, Herry P. J.; den Boer, Johan A.; Nijenhuis, Ellert R. S.

    2012-01-01

    Background Dissociative identity disorder (DID) is a disputed psychiatric disorder. Research findings and clinical observations suggest that DID involves an authentic mental disorder related to factors such as traumatization and disrupted attachment. A competing view indicates that DID is due to fantasy proneness, suggestibility, suggestion, and role-playing. Here we examine whether dissociative identity state-dependent psychobiological features in DID can be induced in high or low fantasy prone individuals by instructed and motivated role-playing, and suggestion. Methodology/Principal Findings DID patients, high fantasy prone and low fantasy prone controls were studied in two different types of identity states (neutral and trauma-related) in an autobiographical memory script-driven (neutral or trauma-related) imagery paradigm. The controls were instructed to enact the two DID identity states. Twenty-nine subjects participated in the study: 11 patients with DID, 10 high fantasy prone DID simulating controls, and 8 low fantasy prone DID simulating controls. Autonomic and subjective reactions were obtained. Differences in psychophysiological and neural activation patterns were found between the DID patients and both high and low fantasy prone controls. That is, the identity states in DID were not convincingly enacted by DID simulating controls. Thus, important differences regarding regional cerebral bloodflow and psychophysiological responses for different types of identity states in patients with DID were upheld after controlling for DID simulation. Conclusions/Significance The findings are at odds with the idea that differences among different types of dissociative identity states in DID can be explained by high fantasy proneness, motivated role-enactment, and suggestion. They indicate that DID does not have a sociocultural (e.g., iatrogenic) origin. PMID:22768068

  10. Fact or factitious? A psychobiological study of authentic and simulated dissociative identity states.

    Science.gov (United States)

    Reinders, A A T S; Reinders, A A T Simone; Willemsen, Antoon T M; Vos, Herry P J; den Boer, Johan A; Nijenhuis, Ellert R S

    2012-01-01

    Dissociative identity disorder (DID) is a disputed psychiatric disorder. Research findings and clinical observations suggest that DID involves an authentic mental disorder related to factors such as traumatization and disrupted attachment. A competing view indicates that DID is due to fantasy proneness, suggestibility, suggestion, and role-playing. Here we examine whether dissociative identity state-dependent psychobiological features in DID can be induced in high or low fantasy prone individuals by instructed and motivated role-playing, and suggestion. DID patients, high fantasy prone and low fantasy prone controls were studied in two different types of identity states (neutral and trauma-related) in an autobiographical memory script-driven (neutral or trauma-related) imagery paradigm. The controls were instructed to enact the two DID identity states. Twenty-nine subjects participated in the study: 11 patients with DID, 10 high fantasy prone DID simulating controls, and 8 low fantasy prone DID simulating controls. Autonomic and subjective reactions were obtained. Differences in psychophysiological and neural activation patterns were found between the DID patients and both high and low fantasy prone controls. That is, the identity states in DID were not convincingly enacted by DID simulating controls. Thus, important differences regarding regional cerebral bloodflow and psychophysiological responses for different types of identity states in patients with DID were upheld after controlling for DID simulation. The findings are at odds with the idea that differences among different types of dissociative identity states in DID can be explained by high fantasy proneness, motivated role-enactment, and suggestion. They indicate that DID does not have a sociocultural (e.g., iatrogenic) origin.

  11. Fact or factitious? A psychobiological study of authentic and simulated dissociative identity states.

    Directory of Open Access Journals (Sweden)

    A A T S Reinders

    Full Text Available BACKGROUND: Dissociative identity disorder (DID is a disputed psychiatric disorder. Research findings and clinical observations suggest that DID involves an authentic mental disorder related to factors such as traumatization and disrupted attachment. A competing view indicates that DID is due to fantasy proneness, suggestibility, suggestion, and role-playing. Here we examine whether dissociative identity state-dependent psychobiological features in DID can be induced in high or low fantasy prone individuals by instructed and motivated role-playing, and suggestion. METHODOLOGY/PRINCIPAL FINDINGS: DID patients, high fantasy prone and low fantasy prone controls were studied in two different types of identity states (neutral and trauma-related in an autobiographical memory script-driven (neutral or trauma-related imagery paradigm. The controls were instructed to enact the two DID identity states. Twenty-nine subjects participated in the study: 11 patients with DID, 10 high fantasy prone DID simulating controls, and 8 low fantasy prone DID simulating controls. Autonomic and subjective reactions were obtained. Differences in psychophysiological and neural activation patterns were found between the DID patients and both high and low fantasy prone controls. That is, the identity states in DID were not convincingly enacted by DID simulating controls. Thus, important differences regarding regional cerebral bloodflow and psychophysiological responses for different types of identity states in patients with DID were upheld after controlling for DID simulation. CONCLUSIONS/SIGNIFICANCE: The findings are at odds with the idea that differences among different types of dissociative identity states in DID can be explained by high fantasy proneness, motivated role-enactment, and suggestion. They indicate that DID does not have a sociocultural (e.g., iatrogenic origin.

  12. A possible highly active supported Ni dimer catalyst for O{sub 2} dissociation: A first-principles study

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Shan [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China); Zhang, Yanxing, E-mail: 2016025@htu.edu.cn [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China); Zhang, Xilin; Mao, Jianjun [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China); Yang, Zongxian, E-mail: yzx@henannu.edu.cn [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China); Collaborative Innovation Center of Nano Functional Materials and Applications, Henan Province (China)

    2017-04-30

    Graphical abstract: The minimum energy paths (MEPs) for the dissociation process of O{sub 2} on the surfaces of bare YSZ (111) and Ni{sub n}/YSZ (111) (n = 1, 2 and 3). - Highlights: • The catalytic activity of supported metal catalysts is closely related to the size of metal particles. • The dissociation of O{sub 2} on the YSZ (111) surface is largely enhanced by the supported Ni cluster. • The supported Ni dimer is predicted to be the smallest Ni cluster needed for efficient O{sub 2} dissociation. • The results would provide an important reference to improve the activity and efficiency of the Ni/YSZ(111) nanocomposite catalysts in cost-effective materials. - Abstract: The adsorption and dissociation of O{sub 2} on the supported small nickel clusters with one-, two-, three-Ni atoms on yttria-stabilized zirconia (YSZ) (111) surfaces, as well as those on the bare YSZ(111) and Ni(111) surfaces are comparatively studied using ab initio density functional theory calculations. It is found that the dissociation of O{sub 2} on the YSZ(111) surface is largely enhanced by the supported Ni dimer, which is predicted to be the smallest Ni cluster needed for efficient O{sub 2} dissociation. The results would provide an important reference to improve the activity and efficiency of the Ni/YSZ(111) nanocomposite catalysts in cost-effective materials.

  13. Study of diffractive dissociation especially into strange and charmed particles with EHS

    CERN Multimedia

    2002-01-01

    The diffractive production of heavy quark-antiquark pairs leading to strangeness-antistrangeness and charm-anticharm systems is intended to be measured in this experiment. The use of the rapid cycling bubble chamber (RCBC) with a volume of 100 x 40 x 40 cm$^{3}$ and a picture taking rate of 15 Hz as vertex detector and EHS as forward spectrometer is suitable for the first step of this physics programme. Inclusive cross-sections for diffraction dissociation into $s\\bar{s}$ are lacking whereas diffractive $c\\bar{c}$ production is already better known. The gain of more insight into the mechanism of heavy quark-antiquark production, exclusive diffractive reactions with $\\pi^{0}$'s, diffractive resonance production and also the extraction of data for the double Pomeron exchange mechanism are envisaged. \\\\\\\\ This experiment will be run in two parts, the first one recording the entire unbiased sample of $pp$ and $\\pi^{-}p$ interactions, the second however using triggering for beam and high mass target diffraction di...

  14. Duality in diffraction dissociations

    International Nuclear Information System (INIS)

    Santoro, Alberto.

    1977-01-01

    Diffractive dissociations (aN→a*πN) are naturally explained and a model that accounts for the three-variable correlation (mass-transfer-Jackson angle correlation) is presented. This model takes into account the three possible exchanges: t (pion), u(a*) and s(a) channel exchanger. The physical consequences of the model are: a strong mass-slope correlation due to the zeros of the amplitude, a factorization of diffractive dissociations (factorization of the Pomeron), the possibility of extending this model to double diffractive dissociation and diffraction by nuclei. This model was applied to the NN→NπN reaction. Using the usual parameters of the Deck model, a comparison is made with experiments for all available distributions. the strong slope of the peak at 1400 MeV is naturally explained [fr

  15. Genetic and Environmental Basis of the Relationship Between Dissociative Experiences and Cloninger’s Temperament and Character Dimensions – Pilot Study

    Directory of Open Access Journals (Sweden)

    Domozych Wojciech

    2016-12-01

    Full Text Available Dissociation is commonly regarded as a disruption in the normally integrated functions of memory, knowledge, affect, sensation or behavior. The present study utilized behavioral genetics’ methodology to investigate genetic and environmental basis of the relationship between dissociation and Cloninger’s temperament and character traits. A sample of 83 monozygotic and 65 dizygotic twins were administered self-report measures which assessed dissociative experiences along with personality dimensions. Significant correlations and high loads of common genetic variance between dissociative experiences and personality traits of novelty seeking, self-directedness, cooperativeness and self-transcendence were identified. Heritability of dissociative experiences was estimated at 62%. The study shows that there exists a considerable amount of genetic variance overlap between dissociation and personality dimensions. It also supports the hypothesis that propensity to dissociate is highly heritable

  16. Egocentric and allocentric visuospatial working memory in premotor Huntington's disease: A double dissociation with caudate and hippocampal volumes.

    Science.gov (United States)

    Possin, Katherine L; Kim, Hosung; Geschwind, Michael D; Moskowitz, Tacie; Johnson, Erica T; Sha, Sharon J; Apple, Alexandra; Xu, Duan; Miller, Bruce L; Finkbeiner, Steven; Hess, Christopher P; Kramer, Joel H

    2017-07-01

    Our brains represent spatial information in egocentric (self-based) or allocentric (landmark-based) coordinates. Rodent studies have demonstrated a critical role for the caudate in egocentric navigation and the hippocampus in allocentric navigation. We administered tests of egocentric and allocentric working memory to individuals with premotor Huntington's disease (pmHD), which is associated with early caudate nucleus atrophy, and controls. Each test had 80 trials during which subjects were asked to remember 2 locations over 1-sec delays. The only difference between these otherwise identical tests was that locations could only be coded in self-based or landmark-based coordinates. We applied a multiatlas-based segmentation algorithm and computed point-wise Jacobian determinants to measure regional variations in caudate and hippocampal volumes from 3T MRI. As predicted, the pmHD patients were significantly more impaired on egocentric working memory. Only egocentric accuracy correlated with caudate volumes, specifically the dorsolateral caudate head, right more than left, a region that receives dense efferents from dorsolateral prefrontal cortex. In contrast, only allocentric accuracy correlated with hippocampal volumes, specifically intermediate and posterior regions that connect strongly with parahippocampal and posterior parietal cortices. These results indicate that the distinction between egocentric and allocentric navigation applies to working memory. The dorsolateral caudate is important for egocentric working memory, which can explain the disproportionate impairment in pmHD. Allocentric working memory, in contrast, relies on the hippocampus and is relatively spared in pmHD. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Eye movements discriminate fatigue due to chronotypical factors and time spent on task--a double dissociation.

    Directory of Open Access Journals (Sweden)

    Dario Cazzoli

    Full Text Available Systematic differences in circadian rhythmicity are thought to be a substantial factor determining inter-individual differences in fatigue and cognitive performance. The synchronicity effect (when time of testing coincides with the respective circadian peak period seems to play an important role. Eye movements have been shown to be a reliable indicator of fatigue due to sleep deprivation or time spent on cognitive tasks. However, eye movements have not been used so far to investigate the circadian synchronicity effect and the resulting differences in fatigue. The aim of the present study was to assess how different oculomotor parameters in a free visual exploration task are influenced by: a fatigue due to chronotypical factors (being a 'morning type' or an 'evening type'; b fatigue due to the time spent on task. Eighteen healthy participants performed a free visual exploration task of naturalistic pictures while their eye movements were recorded. The task was performed twice, once at their optimal and once at their non-optimal time of the day. Moreover, participants rated their subjective fatigue. The non-optimal time of the day triggered a significant and stable increase in the mean visual fixation duration during the free visual exploration task for both chronotypes. The increase in the mean visual fixation duration correlated with the difference in subjectively perceived fatigue at optimal and non-optimal times of the day. Conversely, the mean saccadic speed significantly and progressively decreased throughout the duration of the task, but was not influenced by the optimal or non-optimal time of the day for both chronotypes. The results suggest that different oculomotor parameters are discriminative for fatigue due to different sources. A decrease in saccadic speed seems to reflect fatigue due to time spent on task, whereas an increase in mean fixation duration a lack of synchronicity between chronotype and time of the day.

  18. Different Mechanism Effect between Gas-Solid and Liquid-Solid Interface on the Three-Phase Coexistence Hydrate System Dissociation in Seawater: A Molecular Dynamics Simulation Study

    Directory of Open Access Journals (Sweden)

    Zhixue Sun

    2017-12-01

    Full Text Available Almost 98% of methane hydrate is stored in the seawater environment, the study of microscopic mechanism for methane hydrate dissociation on the sea floor is of great significance to the development of hydrate production, involving a three-phase coexistence system of seawater (3.5% NaCl + hydrate + methane gas. The molecular dynamics method is used to simulate the hydrate dissociation process. The dissociation of hydrate system depends on diffusion of methane molecules from partially open cages and a layer by layer breakdown of the closed cages. The presence of liquid or gas phases adjacent to the hydrate has an effect on the rate of hydrate dissociation. At the beginning of dissociation process, hydrate layers that are in contact with liquid phase dissociated faster than layers adjacent to the gas phase. As the dissociation continues, the thickness of water film near the hydrate-liquid interface became larger than the hydrate-gas interface giving more resistance to the hydrate dissociation. Dissociation rate of hydrate layers adjacent to gas phase gradually exceeds the dissociation rate of layers adjacent to the liquid phase. The difficulty of methane diffusion in the hydrate-liquid side also brings about change in dissociation rate.

  19. Reliability and validity of the Turkish version of the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D): a preliminary study.

    Science.gov (United States)

    Kundakçi, Turgut; Sar, Vedat; Kiziltan, Emre; Yargiç, Ilhan L; Tutkun, Hamdi

    2014-01-01

    A total of 34 consecutive patients with dissociative identity disorder or dissociative disorder not otherwise specified were evaluated using the Turkish version of the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D). They were compared with a matched control group composed of 34 patients who had a nondissociative psychiatric disorder. Interrater reliability was evaluated by 3 clinicians who assessed videotaped interviews conducted with 5 dissociative and 5 nondissociative patients. All subjects who were previously diagnosed by clinicians as having a dissociative disorder were identified as positive, and all subjects who were previously diagnosed as not having a dissociative disorder were identified as negative. The scores of the main symptom clusters and the total score of the SCID-D differentiated dissociative patients from the nondissociative group. There were strong correlations between the SCID-D and the Dissociative Experiences Scale total and subscale scores. These results are promising for the validity and reliability of the Turkish version of the SCID-D. However, as the present study was conducted on a predominantly female sample with very severe dissociation, these findings should not be generalized to male patients, to dissociative disorders other than dissociative identity disorder, or to broader clinical or nonclinical populations.

  20. Dissociation between morality and disgust: an event-related potential study.

    Science.gov (United States)

    Yang, Qun; Li, An; Xiao, Xiao; Zhang, Ye; Tian, Xuehong

    2014-10-01

    This study explored the neural correlates of morality and disgust, particularly, how the mechanisms that mediate our avoidance of physically disgusting and morally abhorrent behaviors are neurologically dissociated during the time-course of processing. Twelve participants were asked to judge the acceptability of different types of behaviors, which varied in their level of moral wrongness and physical disgust, while event-related potentials (ERPs) were recorded. The main results showed that the two morally wrong conditions elicited greater amplitudes of P300-400 at frontal sites than the neutral condition and the physically disgusting, but not morally wrong, condition. The physically disgusting conditions (with and without moral content) elicited significantly more positive deflections in the 500-600 ms timeframe than the neutral condition at central-posterior sites. These findings indicate that our aversion to harmful substances in the physical environment and offensive behaviors in the social environment may be neurologically dissociable in the temporal dimension. Furthermore, the detection of moral violations may be processed earlier in time than that of physical disgust. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Effect of temperature and ionic strength on the dissociation kinetics and lifetime of PNA-DNA triplexes

    DEFF Research Database (Denmark)

    Kosaganov, Y N; Stetsenko, D A; Lubyako, E N

    2000-01-01

    Dissociation kinetics of triplexes formed by molecules of peptide nucleic acid (PNA) and DNA have been studied. The complexes consisted of oligomeric PNA containing 10 thymine bases and the dA(10) target incorporated in single-stranded (ssDNA) or double-stranded DNA (dsDNA). Their dissociation wa...

  2. Open-longitudinal study of the effect of dissociative symptoms on the response of patients with panic disorder to venlafaxine.

    Science.gov (United States)

    Ural, Cenk; Belli, Hasan; Tabo, Abdulkadir; Akbudak, Mahir

    2015-02-01

    The relationship between Panic Disorder (PD) and dissociation is well known. In this study we aimed to investigate whether or not dissociative experiences affect the response to PD drug treatment. For this purpose, standart dose of venlafaxine was preferred for treatment. 63 patients with PD were included in the study. Venlafaxine treatment with increasing dose was administered to each patient during a 10-week period. The Panic Disorder Severity Scale (PDSS) and the Dissociation Questionnaire (DIS-Q) were applied to the patients at the beginning of the study. Patients were divided into two groups based on DIS-Q scores. PDSS was applied again to both groups at the end of 10-week treatment. No difference between sociodemographic data and PDSS scores of two groups - patients with low DIS-Q scores (2.5) - was found at the beginning. At the end of the study, a significant decrease in PDSS scores measured in both groups was detected. However, the decrease in PDSS score for the group with lower DIS-Q score was at a higher percentage (z=-3.822, p=0.0001). These results depict that dissociative symptoms accompanying PD affect psychopharmacological treatment in a negative way. Reevaluation of dissociative symptoms at the beginning and end of treatment would help in planning personal therapy. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. MOLECULAR BEAM STUDIES OF IR LASER INDUCED MULTIPHOTON DISSOCIATION AND VIBRATIONAL PREDISSOCIATION

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yuan T.; Shen, Y. Ron

    1980-06-01

    The advancement of crossed molecular beam methods, modern spectroscopy and laser technology allows us to observe chemical reactions on atomic and molecular levels in great detail. After a brief history of crossed molecular beams studies, the author describes and discusses the universal molecular beam apparatus and gives examples of crossed molecular beam studies. The crossed beam technique is compared to other techniques used to provide microscopic information on reaction dynamics. Application of crossed laser and molecular beam studies to the problem of IR multiphoton dissociation of polyatomic molecules is discussed. Study of vibrational predissociation of hydrogen-bonded and van der Waals molecular clusters are discussed. Future cases that the author considers worth pursuing that could benefit from the collisionless environment of molecular beams are enumerated.

  4. Three dimensions of dissociative amnesia.

    Science.gov (United States)

    Dell, Paul F

    2013-01-01

    Principal axis factor analysis with promax rotation extracted 3 factors from the 42 memory and amnesia items of the Multidimensional Inventory of Dissociation (MID) database (N = 2,569): Discovering Dissociated Actions, Lapses of Recent Memory and Skills, and Gaps in Remote Memory. The 3 factors' shared variance ranged from 36% to 64%. Construed as scales, the 3 factor scales had Cronbach's alpha coefficients of .96, .94, and .93, respectively. The scales correlated strongly with mean Dissociative Experiences Scale scores, mean MID scores, and total scores on the Structured Clinical Interview for DSM-IV Dissociative Disorders-Revised (SCID-D-R). What is interesting is that the 3 amnesia factors exhibited a range of correlations with SCID-D-R Amnesia scores (.52, .63, and .70, respectively), suggesting that the SCID-D-R Amnesia score emphasizes gaps in remote memory over amnesias related to dissociative identity disorder. The 3 amnesia factor scales exhibited a clinically meaningful pattern of significant differences among dissociative identity disorder, dissociative disorder not otherwise specified-1, dissociative amnesia, depersonalization disorder, and nonclinical participants. The 3 amnesia factors may have greater clinical utility for frontline clinicians than (a) amnesia as discussed in the context of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, nosology of the dissociative disorders or (b) P. Janet's (1893/1977 ) 4-fold classification of dissociative amnesia. The author recommends systematic study of the phenomenological differences within specific dissociative symptoms and their differential relationship to specific dissociative disorders.

  5. Dissociative part-dependent biopsychosocial reactions to backward masked angry and neutral faces : An fMRI study of dissociative identity disorder

    NARCIS (Netherlands)

    Schlumpf, Yolanda R.; Nijenhuis, Ellert R. S.; Chalavi, Sima; Weder, Ekaterina V.; Zimmermann, Eva; Luechinger, Roger; La Marca, Roberto; Reinders, A. A. T. Simone; Jaencke, Lutz

    2013-01-01

    Objective: The Theory of Structural Dissociation of the Personality (TSDP) proposes that dissociative identity disorder (DID) patients are fixed in traumatic memories as "Emotional Parts" (EP), but mentally avoid these as "Apparently Normal Parts" of the personality (ANP). We tested the hypotheses

  6. MORPHOLOGICAL CHARACTERISTIC OF SPERMATOGONIA AND TESTES DISSOCIATION : A Preliminary Study for the Germ Cell Transplantation in Giant Gouramy (Osphronemus gouramy

    Directory of Open Access Journals (Sweden)

    Irma Andriani

    2010-12-01

    Full Text Available The recent study were attempting to develop spermatogonial germ cell transplantation as a tool to preserve and propagate male germ-plasm from endangered fish species, as well as to produce surrogate broodstock of commercially valuable fish. Spermatogonia identification and testes dissociation were the first necessary steps to obtain highly amount and viable population of spermatogonia as donor cells for transplantation. Using giant gouramy testes as a model, spermatogonia was histological characterized and two methods of testes dissociations were compared (i.e. medium A contained 0.5% trypsin in PBS and medium B contained 0.5% trypsin and DNase 10 IU/μL in PBS complemented with CaCl2, Hepes and FCS. Optimal incubation times (1, 2, 3, 4 and 5 hours in dissociation medium were also determined. Freshly isolated testes of immature giant gouramy were minced in dissociation medium and then incubated to get monodisperce cell suspension. Parameters observed were number and viability of spermatogonia (ø > 10 μm. The viability was analyzed using trypan blue exclusion dye. The results showed that the average number of spermatogonia observed in medium B was higher than in medium A (P0.05. The viability of spermatogonia decreased by the increasing duration time of dissociation. The viability of spermatogonia started to decrease significantly in 2 hours incubation time in medium A and 4 hours incubation time in medium B (P<0.05. In conclusion, application of dissociation medium B yielded higher number of viable spermatogonia than dissociation medium A.

  7. Carbon disulfide (CS{sub 2}) adsorption and dissociation on the Cu(100) surface: A quantum chemical study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wenju, E-mail: wangwenju1982@163.com; Fan, Lili; Wang, Guoping, E-mail: wgp1976@163.com

    2017-08-31

    Highlights: • CS{sub 2}, CS, C and S are strongly chemadsorbed on the Cu(100) surface. • C/S/S, S/CS and CS{sub 2} accord to a decreased adsorption strength on the Cu(100). • The asymmetric model CS{sub 2}(II) is easier to dissociate on the Cu(100) surface. - Abstract: Density functional theory (DFT) is used to examine the adsorption and dissociation of CS{sub 2} on the Cu(100) surface. This study evaluates the adsorption energies and geometries of the species (CS{sub 2}, CS, C and S) adsorption on the Cu(100) surface, as well as that coadsorption of CS and a S atom, and that coadsorption of C atom and two S atoms. The results indicate that the species (CS{sub 2}, CS, C and S) are strongly chemadsorbed on the Cu(100) surface through the C−Cu and/or S−Cu bond with an increased adsorption energy (C/S/S > S/CS > CS{sub 2}). Two pathways for CS{sub 2} dissociation on the Cu(100) surface are constructed, and the energy barrier and reaction energy of each step are calculated. It shows that the dissociated energy barrier of the second C−S bond is 0.25 eV higher than that of the first C−S bond in the pathway 1, but in the pathway 2, the dissociated energy barrier of the second C−S bond is 0.11 eV lower than that of the first C−S bond. Comparing the highest dissociated energy barrier of pathway 1 (0.68 eV) and pathway 2 (0.5 eV), the structure of S/C/S(II) is regarded as a preferable product for the dissociation of CS{sub 2} on the Cu(100) surface.

  8. A density functional study on adsorption and dissociation of O 2 on Ir(1 0 0) surface

    Science.gov (United States)

    Erikat, I. A.; Hamad, B. A.; Khalifeh, J. M.

    2011-06-01

    The adsorption and the reaction barrier for the dissociation of O 2 on Ir(1 0 0) surface are studied using periodic self-consistent density functional theory (DFT) calculations. Dissociative adsorption is found to be energetically more favorable compared to molecular adsorption. Parallel approaches Prl1 and Prl2 on a hollow site with the same adsorption energy of -3.93 eV for both of them are found to have the most energetically preferred sites of adsorptions among all the studied cases. Hybridization between p-O 2 and d-metal orbitals is responsible for the dissociative adsorption. The minimum energy path is determined by using the nudge elastic band method (NEB). We found that the dissociation occurs immediately and very early in the dissociation path with a small activation barrier (0.26 eV), which means that molecular adsorption of O 2 on Ir(1 0 0) surface occurs at very low temperatures; this is consistent with previous experimental and theoretical studies on Ir surfaces.

  9. First-principles study of hydrogen dissociation and diffusion on transition metal-doped Mg(0 0 0 1) surfaces

    International Nuclear Information System (INIS)

    Wang, Zhiwen; Guo, Xinjun; Wu, Mingyi; Sun, Qiang; Jia, Yu

    2014-01-01

    First-principles calculations within the density functional theory (DFT) have been carried out to study hydrogen molecules dissociation and diffusion on clean and transition metals (TMs) doped Mg(0 0 0 1) surfaces following Pozzo et al. work. Firstly, the stability of Mg(0 0 0 1) surface doped with transition metals atom has been studied. The results showed that transition metals on the left of the table tend to substitute Mg in the second layer, while the other transition metals prefer to substitute Mg in the first layer. Secondly, we studied hydrogen molecules dissociation and diffusion on clean and Mg(0 0 0 1) surfaces which the transition metal atoms substituted both in the first layer and second layer. When transition metal atoms substitute in the first layer, the results agree with the Pozzo et al. result; when transition metal atoms substitute in the second layer, the results showed that the transition metals on the left of the periodic table impact on the dissociation barriers is less. However, for the transition metals (Mn, Fe, Co, Ni) on the right, there is a great impact on the barriers. The transition metals doped surfaces bind the dissociated H atoms loosely, making them easily diffused. The results further reveal that the Fe dopant on the Mg surface is the best choice for H 2 dissociation and hydrogen storage.

  10. Ozone-induced dissociation on a traveling wave high-resolution mass spectrometer for determination of double-bond position in lipids.

    Science.gov (United States)

    Vu, Ngoc; Brown, Jeffery; Giles, Kevin; Zhang, Qibin

    2017-09-15

    The position of C=C within fatty acyl chains affects the biological function of lipids. Ozone-induced dissociation mass spectrometry (OzID-MS) has great potential in determination of lipid double-bond position, but has generally been implemented on low-resolution ion trap mass spectrometers. In addition, most of the OzID-MS experiments carried out so far were focused on the sodiated adducts of lipids; fragmentation of the most commonly observed protonated ions generated in LC/MS-based lipidomics workflow has been less explored. Ozone generated in line from an ozone generator was connected to the trap and transfer gas supply line of a Synapt G2 high-resolution mass spectrometer. Protonated ions of different phosphatidylcholines (PC) were generated by electrospray ionization through direct infusion. Different parameters, including traveling wave height and velocity, trap entrance and DC potential, were adjusted to maximize the OzID efficiency. sn-positional isomers and cis/trans isomers of lipids were compared for their reactivity with ozone. Traveling wave height and velocity were tuned to prolong the encounter time between lipid ions and ozone, and resulted in improved OzID efficiency, as did increasing trapping region DC and entrance potential. Under optimized settings, at least 1000 times enhancement in OzID efficiency was achieved compared to that under default settings for monounsaturated PC standards. Monounsaturated C=C in the sn-2 PC isomer reacted faster with ozone than the sn-1 isomer. Similarly, the C=C in trans PC reacted faster than in cis PC. This is the first implementation of OzID in the trap and transfer region of a traveling wave enabled high-resolution mass spectrometer. The OzID reaction efficiency is significantly improved by slowing down ions in the trap region for their prolonged interaction with ozone. This will facilitate application of high-resolution OzID-MS in lipidomics. Copyright © 2017 John Wiley & Sons, Ltd.

  11. Infant attachment insecurity and dissociative symptomatology: findings from the NICHD Study of Early Child Care and Youth Development.

    Science.gov (United States)

    Haltigan, John D; Roisman, Glenn I

    2015-01-01

    Based on data from the NICHD Study of Early Child Care and Youth Development (N = 1,149), the current article provides the first large-sample investigation of associations between different forms of infant attachment insecurity and dissociative symptomatology from childhood through midadolescence as measured by scales based on the mother, teacher, and youth self-report versions of the Achenbach System of Empirically Based Assessments. Findings did not replicate the previously reported and highly cited evidence that infant attachment disorganization is associated with dissociative symptomatology. In contrast, correlations of small magnitude were observed between infant avoidance and dissociative symptomatology, as assessed by teachers and mothers (but not self-report). Results were not moderated by contextual risk. Limitations of the study included the absence of measures of maltreatment and interpersonal trauma, leaving open the possibility that infant attachment disorganization is a diathesis for later dissociation in the context of severe and/or chronic trauma. Nevertheless, the present results strongly indicate the need for additional research exploring the possible role of environmental factors in the development of dissociative symptomatology. © 2014 Michigan Association for Infant Mental Health.

  12. Study of dissociative collisions of hydrogen-line ions by mean of angular and energy distributions

    International Nuclear Information System (INIS)

    Martinez, H.; Urquijo, J. de; Cisneros, C.; Alvarez, J.

    1988-01-01

    Angular and energy distribution of fragments produced in a collision, employed in conjunction with the 'step-model' that means excitation and binary dissociation, are used to determine the binding energy of H 3 (D 3 ) and HD + 2 and also to identify the principal channels in the dissociation processes. (A.C.A.S.) [pt

  13. Study of inner shell excitation effect on C-H dissociation in aromatic hydrocarbon solids

    International Nuclear Information System (INIS)

    Shimoyama, I.; Nakagawa, K.; Matsui, F.; Yoem, H.W.; Ohta, T.; Tanaka, S.; Mase, K.

    2000-01-01

    Since Carson et al. have reported the 'Coulomb Explosion' model, an inner shell excitation effect on dissociation is intensively attractive because multiply ionized states induced by Auger decay enhance dissociation. This effect on chemical reaction has been investigated especially for surface reaction processes such as desorption induced electron transition (DIET). Recently, some studies on DIET using monochromatic soft X-rays have reported that desorption yield depends on not only the repulsion energy but also the character of excited molecular orbital (MO). This means that inner shell resonant excitations to different MO result in different desorption. This Inner Shell Resonant Excitation Effect' is very interesting because it enables us to control photochemical reactions with synchrotron radiation. Two important problems lie ahead of us for application of this effect. One problem is secondary effect. When one irradiates soft X-rays to materials, following reaction includes two kinds of mixed effects; fundamental effect (FE) and secondary effect (SE). FE originates from interactions between photons and materials, while SE originates from interactions between secondary electrons and materials. Since the inner shell resonant excitation effect essentially originates from FE, it is important to know the ratio of FE to SE in a photochemical reaction in order to estimate true magnitude of the inner shell resonant excitation effect. The other problem is the difference between surface reaction and bulk reaction. Weather the bulk reaction shows inner shell excitation effect as well as the surface reaction does? Some studies of the inner shell excitation effect on damage in bulk have been reported. To our knowledge, however, there is no study which reports the difference between bulk and surface reaction. In this paper, we present two kinds of works with aromatic hydrocarbon compounds. First, we present photon stimulated ion desorption (PSID) on condensed benzene to study

  14. Dissociation between facial and bodily expressions in emotion recognition: A case study.

    Science.gov (United States)

    Leiva, Samanta; Margulis, Laura; Micciulli, Andrea; Ferreres, Aldo

    2017-12-21

    Existing single-case studies have reported deficit in recognizing basic emotions through facial expression and unaffected performance with body expressions, but not the opposite pattern. The aim of this paper is to present a case study with impaired emotion recognition through body expressions and intact performance with facial expressions. In this single-case study we assessed a 30-year-old patient with autism spectrum disorder, without intellectual disability, and a healthy control group (n = 30) with four tasks of basic and complex emotion recognition through face and body movements, and two non-emotional control tasks. To analyze the dissociation between facial and body expressions, we used Crawford and Garthwaite's operational criteria, and we compared the patient and the control group performance with a modified one-tailed t-test designed specifically for single-case studies. There were no statistically significant differences between the patient's and the control group's performances on the non-emotional body movement task or the facial perception task. For both kinds of emotions (basic and complex) when the patient's performance was compared to the control group's, statistically significant differences were only observed for the recognition of body expressions. There were no significant differences between the patient's and the control group's correct answers for emotional facial stimuli. Our results showed a profile of impaired emotion recognition through body expressions and intact performance with facial expressions. This is the first case study that describes the existence of this kind of dissociation pattern between facial and body expressions of basic and complex emotions.

  15. Ethylene dissociation on flat and stepped Ni(111): A combined STM and DFT study

    DEFF Research Database (Denmark)

    Vang, R.T.; Honkala, Johanna Karoliina; Dahl, S.

    2006-01-01

    The dissociative adsorption of ethylene (C(2)H(4)) on Ni(111) was studied by scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. The STM studies reveal that ethylene decomposes exclusively at the step edges at room temperature. However, the step edge sites...... are poisoned by the reaction products and thus only a small brim of decomposed ethylene is formed. At 500 K decomposition on the (111) facets leads to a continuous growth of carbidic islands, which nucleate along the step edges. DFT calculations were performed for several intermediate steps...... in the decomposition of ethylene on both Ni(111) and the stepped Ni(211) surface. In general the Ni(211) surface is found to have a higher reactivity than the Ni(111) surface. Furthermore, the calculations show that the influence of step edge atoms is very different for the different reaction pathways. In particular...

  16. First-principles study of molecular NO dissociation on Ir(100) surface

    Science.gov (United States)

    Erikat, I. A.; Hamad, B. A.; Khalifeh, J. M.

    2014-02-01

    The dissociation of NO on Ir(100) surface is investigated using density functional theory (DFT). The pathway and transition state (TS) of the dissociation of NO molecule are determined using climbing image nudge elastic band (CI-NEB). The prerequisite state of NO dissociation is determining the most stable sites of the reactant and products. We found that the most energetically stable sites are the hollow for N atom and the bridge for NO molecule as well as O atom. We found that the bending of NO is the first step of the dissociation reaction due to the increase of the back-donation from the d-band of Ir to 2 π ∗ orbital of NO, which causes the weakening of NO bond. The dissociation energy barrier of NO molecule on Ir(100) surface is 0.49 eV.

  17. A triazolam/amphetamine dose-effect interaction study: dissociation of effects on memory versus arousal.

    Science.gov (United States)

    Mintzer, Miriam Z; Griffiths, Roland R

    2007-06-01

    In addition to producing robust memory impairment, benzodiazepines also induce marked sedation. Thus, it is possible that the observed amnestic effects are secondary to more global sedative effects and do not reflect a specific primary benzodiazepine effect on memory mechanisms. The objective was to use the nonspecific stimulant d-amphetamine to dissociate the sedative and memory-impairing effects of the benzodiazepine triazolam. Single oral doses of placebo, triazolam alone (0.25, 0.50 mg/70 kg), d-amphetamine sulfate alone (20, 30 mg/70 kg), and triazolam (0.25, 0.50 mg/70 kg) and d-amphetamine sulfate (20, 30 mg/70 kg) conjointly (at all dose combinations) were administered to 18 healthy adult participants across nine sessions in a double-blind, staggered-dosing, crossover design. In addition to standard data analyses, analyses were also conducted on z-score standardized data, enabling effects to be directly compared across measures. Relative to the sedative measures, the memory measures generally exhibited a pattern of less reversal of triazolam's effects by d-amphetamine. The memory measures ranged in degree of reversal such that the most reversal was observed for reaction time on the n-back working memory task, and the least reversal was observed for accuracy on the Sternberg working memory task, with most measures showing an overall pattern of partial reversal. Benzodiazepines have specific effects on memory that are not merely a by-product of the drugs' sedative effects, and the degree to which sedative effects contribute to the amnestic effects varies as a function of the particular memory process being assessed.

  18. Dissociation and diffusion of hydrogen on defect-free and vacancy defective Mg (0001) surfaces: A density functional theory study

    Energy Technology Data Exchange (ETDEWEB)

    Han, Zongying [College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266590 (China); Union Research Center of Fuel Cell, School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Chen, Haipeng [College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266590 (China); College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao 266590 (China); Zhou, Shixue, E-mail: zhoushixue66@163.com [College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266590 (China); College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao 266590 (China)

    2017-02-01

    Highlights: • Clarify the effect of vacancy defect on H{sub 2} dissociation on Mg (0001) surface. • Demonstrate the effects of vacancy defect on H atom diffusion. • Reveal the minimum energy diffusion path of H atom from magnesium surface into bulk. - Abstract: First-principles calculations with the density functional theory (DFT) have been carried out to study dissociation and diffusion of hydrogen on defect-free and vacancy defective Mg (0001) surfaces. Results show that energy barriers of 1.42 eV and 1.28 eV require to be overcome for H{sub 2} dissociation on defect-free and vacancy defective Mg (0001) surfaces respectively, indicating that reactivity of Mg (0001) surface is moderately increased due to vacancy defect. Besides, the existence of vacancy defect changes the preferential H atom diffusion entrance to the subsurface and reduces the diffusion energy barrier. An interesting remark is that the minimum energy diffusion path of H atom from magnesium surface into bulk is a spiral channel formed by staggered octahedral and tetrahedral interstitials. The diffusion barriers computed for H atom penetration from the surface into inner-layers are all less than 0.70 eV, which is much smaller than the activation energy for H{sub 2} dissociation on the Mg (0001) surface. This suggests that H{sub 2} dissociation is more likely than H diffusion to be rate-limiting step for magnesium hydrogenation.

  19. Use of surface plasmon resonance (SPR) to study the dissociation and polysaccharide binding of casein micelles and caseins.

    Science.gov (United States)

    Thompson, Abby K; Singh, Harjinder; Dalgleish, Douglas G

    2010-11-24

    Tests were made to determine whether surface plasmon resonance (SPR) could be used as a technique to study the dissociation properties of bovine casein micelles or of sodium caseinate and the interactions between these protein particles and different polysaccharides. Surfaces of bound micelles or caseinate were made, and the changes in refractive index of these layers were used to define changes in the structures of the chemisorbed material. The technique appears to have some potential for studying details of the dissociation of casein micelles and of the binding of different polysaccharides to caseins.

  20. An ab initio study of potential energy surfaces of CH 3COCN dissociation on the low-lying states

    Science.gov (United States)

    Ding, Wan-Jian; Fang, Wei-Hai; Liu, Ruo-Zhuang

    2002-01-01

    The C-CH 3 and C-CN bond dissociations of CH 3COCN on S 1 and T 1 surfaces are studied at the CAS(8,7)/cc-pVDZ level. The results show that the intersystem crossing from S 1 to T 1 is a favorable pathway of S 1 deactivation. Once on the T 1 surface, the system can dissociate adiabatically to CH3 ( X˜)+ OCCN ( X˜) or CN ( X˜)+ CH3CO ( X˜) , but the former has some preference over the latter. This mechanism is consistent with Cheng's presumption deduced from the experimental facts and theoretical considerations. A comparison with other asymmetrically substituted carbonyl compounds suggests that the selectivity of the α-bond cleavage is mainly dependent on the mechanism of dissociation.

  1. The Memory of What We Do Not Recall: Dissociations and Theoretical Debates in the Study of Implicit Memory

    Science.gov (United States)

    Ramos, Tania; Marques, João; Garcia-Marques, Leonel

    2017-01-01

    Implicit memory reflects itself on situations in which previously acquired information is expressed, without awareness or intention. The study of implicit memory has had a profound impact on how researchers have investigated the human memory. In this paper, we review the main studies which have revealed dissociations between direct and indirect…

  2. Insights on finite size effects in ab initio study of CO adsorption and dissociation on Fe 110 surface

    International Nuclear Information System (INIS)

    Chakrabarty, Aurab; Bouhali, Othmane; Mousseau, Normand; Becquart, Charlotte S.; El-Mellouhi, Fedwa

    2016-01-01

    Adsorption and dissociation of hydrocarbons on metallic surfaces represent crucial steps on the path to carburization, eventually leading to dusting corrosion. While adsorption of CO molecules on Fe surface is a barrier-less exothermic process, this is not the case for the dissociation of CO into C and O adatoms and the diffusion of C beneath the surface that are found to be associated with large energy barriers. In practice, these barriers can be affected by numerous factors that combine to favour the CO-Fe reaction such as the abundance of CO and other hydrocarbons as well as the presence of structural defects. From a numerical point of view, studying these factors is challenging and a step-by-step approach is necessary to assess, in particular, the influence of the finite box size on the reaction parameters for adsorption and dissociation of CO on metal surfaces. Here, we use density functional theory (DFT) total energy calculations with the climbing-image nudged elastic band method to estimate the adsorption energies and dissociation barriers for different CO coverages with surface supercells of different sizes. We further compute the effect of periodic boundary condition for DFT calculations and find that the contribution from van der Waals interaction in the computation of adsorption parameters is important as they contribute to correcting the finite-size error in small systems. The dissociation process involves carbon insertion into the Fe surface causing a lattice deformation that requires a larger surface system for unrestricted relaxation. We show that, in the larger surface systems associated with dilute CO-coverages, C-insertion is energetically more favourable, leading to a significant decrease in the dissociation barrier. This observation suggests that a large surface system with dilute coverage is necessary for all similar metal-hydrocarbon reactions in order to study their fundamental electronic mechanisms, as an isolated phenomenon, free from

  3. Insights on finite size effects in ab initio study of CO adsorption and dissociation on Fe 110 surface

    Energy Technology Data Exchange (ETDEWEB)

    Chakrabarty, Aurab, E-mail: aurab.chakrabarty@qatar.tamu.edu; Bouhali, Othmane [Texas A& M University at Qatar, P.O. Box 23874, Doha (Qatar); Mousseau, Normand [Département de Physique and RQMP, Université de Montréal, Case Postale 6128, Succursale Centre-ville, Montréal, Québec H3C 3J7 (Canada); Becquart, Charlotte S. [UMET, UMR CNRS 8207, ENSCL, Université Lille I, 59655 Villeneuve d' Ascq Cédex (France); El-Mellouhi, Fedwa [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, P.O. Box 5825, Doha (Qatar)

    2016-08-07

    Adsorption and dissociation of hydrocarbons on metallic surfaces represent crucial steps on the path to carburization, eventually leading to dusting corrosion. While adsorption of CO molecules on Fe surface is a barrier-less exothermic process, this is not the case for the dissociation of CO into C and O adatoms and the diffusion of C beneath the surface that are found to be associated with large energy barriers. In practice, these barriers can be affected by numerous factors that combine to favour the CO-Fe reaction such as the abundance of CO and other hydrocarbons as well as the presence of structural defects. From a numerical point of view, studying these factors is challenging and a step-by-step approach is necessary to assess, in particular, the influence of the finite box size on the reaction parameters for adsorption and dissociation of CO on metal surfaces. Here, we use density functional theory (DFT) total energy calculations with the climbing-image nudged elastic band method to estimate the adsorption energies and dissociation barriers for different CO coverages with surface supercells of different sizes. We further compute the effect of periodic boundary condition for DFT calculations and find that the contribution from van der Waals interaction in the computation of adsorption parameters is important as they contribute to correcting the finite-size error in small systems. The dissociation process involves carbon insertion into the Fe surface causing a lattice deformation that requires a larger surface system for unrestricted relaxation. We show that, in the larger surface systems associated with dilute CO-coverages, C-insertion is energetically more favourable, leading to a significant decrease in the dissociation barrier. This observation suggests that a large surface system with dilute coverage is necessary for all similar metal-hydrocarbon reactions in order to study their fundamental electronic mechanisms, as an isolated phenomenon, free from

  4. Double Shell Tank (DST) Human Factors Study

    International Nuclear Information System (INIS)

    CHAFFEE, G.A.

    1994-01-01

    This report documents the data collection and analyses that were performed in development of material to be used in the Human Factors chapter for the upgrade to the Safety Analysis Report (SAR) for the Double-Shell Tank Farms (DSTF). This study was conducted to collect the data that is necessary to prepare the Human Factors chapter for the upgrade of the SAR for the DSTF. Requirements for the HF chapter of the SAR generally dictate that the facility management describe how the consideration of operator capabilities and limitations and operating experience are used in ensuring the safe and effective operation of the facility. Additionally, analysis to indicate the contribution of human error to the safety basis accidents or events must be reported. Since the DSTF is a mature operating facility and the requirement to prepare a HF chapter is new, it was not expected that the consideration of HF principles would be an explicit part of DSTF operations. It can be expected, however, that the programs that guide the daily operations at the DSTF contain provisions for the consideration of the needs of their operating personnel and lessons learned from prior experience. Consideration of both the SAR requirements and the nature of the DSTF operations led to the following objectives being defined for the study: (1) to identify the programs at the OSTF where human performance may be considered; (2) to describe how HF principles and operating experience are used to ensure safe and reliable human performance at the DSTF; (3) to describe how HF principles and operating experience are considered as modifications or improvements are made at the DSTF; and (4) to perform task analysis sufficient to understand the potential for human error in OSTF operations

  5. Diffraction dissociation at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Jenkovszky, Laszlo [Bogolyubov Institute for Theoretical Physics (BITP), Ukrainian National Academy of Sciences 14-b, Metrolohichna str., Kiev, 03680, Ukraine and Wigner Research Centre for Physics, Hungarian Academy of Sciences 1525 Budapest, POB 49 (Hungary); Orava, Risto [Institute of Physics, Division of Elementary Particle Physics, P.O. Box 64 (Gustaf Haellstroeminkatu 2a), FI-00014 University of Helsinki, Finland and CERN, CH-1211 Geneva 23 (Switzerland); Salii, Andrii [Bogolyubov Institute for Theoretical Physics (BITP), Ukrainian National Academy of Sciences 14-b, Metrolohichna str., Kiev, 03680 (Ukraine)

    2013-04-15

    We report on recent calculations of low missing mass single (SD) and double (DD) diffractive dissociation at LHC energies. The calculations are based on a dual-Regge model, dominated by a single Pomeron exchange. The diffractively excited states lie on the nucleon trajectory N*, appended by the isolated Roper resonance. Detailed predictions for the squared momentum transfer and missing mass dependence of the differential and integrated single-and double diffraction dissociation in the kinematical range of present and future LHC measurements are given.

  6. Diffraction dissociation at the LHC

    International Nuclear Information System (INIS)

    Jenkovszky, László; Orava, Risto; Salii, Andrii

    2013-01-01

    We report on recent calculations of low missing mass single (SD) and double (DD) diffractive dissociation at LHC energies. The calculations are based on a dual-Regge model, dominated by a single Pomeron exchange. The diffractively excited states lie on the nucleon trajectory N*, appended by the isolated Roper resonance. Detailed predictions for the squared momentum transfer and missing mass dependence of the differential and integrated single-and double diffraction dissociation in the kinematical range of present and future LHC measurements are given.

  7. Picosecond dissociation of amyloid fibrils with infrared laser: A nonequilibrium simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Hoang Viet, Man; Roland, Christopher, E-mail: cmroland@ncsu.edu; Sagui, Celeste, E-mail: sagui@ncsu.edu [Department of Physics, North Carolina State University, Raleigh, North Carolina 27695-8202 (United States); Derreumaux, Philippe; Nguyen, Phuong H., E-mail: phuong.nguyen@ibpc.fr [Laboratoire de Biochimie Théorique, UPR 9080, CNRS Université Denis Diderot, Sorbonne Paris Cité IBPC, 13 rue Pierre et Marie Curie, 75005 Paris (France); Li, Mai Suan [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Institute for Computational Science and Technology, SBI Building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City (Viet Nam)

    2015-10-21

    Recently, mid-infrared free-electron laser technology has been developed to dissociate amyloid fibrils. Here, we present a theoretical framework for this type of experiment based on laser-induced nonequilibrium all-atom molecular dynamics simulations. We show that the fibril is destroyed due to the strong resonance between its amide I vibrational modes and the laser field. The effects of laser irradiation are determined by a balance between fibril formation and dissociation. While the overall rearrangements of the fibril finish over short time scales, the interaction between the peptides and the solvent continues over much longer times indicating that the waters play an important role in the dissociation process. Our results thus provide new insights into amyloid fibril dissociation by laser techniques and open up new venues to investigate the complex phenomena associated with amyloidogenesis.

  8. Adatom Bond Dissociation in the Collision Between an Adsorbed Atom and Incident Diatomic Molecule: A Classical Trajectory Study

    International Nuclear Information System (INIS)

    Bayhan, U.

    2004-01-01

    The collisional dissociation of the Atom-Surface bond in the diatomic molecule (gas) / atom (ads) collision taking place on a bcc-structure surface have been studied by classical trajectory methods over the collision energy ranges and the attractive well depth of the diatomic molecule (gas) / atom (ads) interactions

  9. Does semantic impairment explain surface dyslexia? VLSM evidence for a double dissociation between regularization errors in reading and semantic errors in picture naming

    Directory of Open Access Journals (Sweden)

    Sara Pillay

    2014-04-01

    adjacent posterior inferior temporal gyrus (blue in figure 1. In contrast, semantic errors during picture naming (red and pink in figure 1 and impaired performance on the semantic matching task (yellow and pink in figure 1 were correlated with more anterior temporal lobe damage and with inferior frontal gyrus involvement. There was substantial overlap between lesion correlates for the two explicit semantic tasks (pink in figure 1, but none between these areas and those correlated with regularization errors. This double dissociation is difficult to accommodate in terms of a common impairment underlying semantic deficits and regularization errors. Lesions in relatively anterior temporal regions appear to produce semantic deficits but not regularization errors, whereas more posterior temporal lesions produce regularization errors but not explicit semantic errors. One possibility is that this posterior temporal region stores whole word representations that do not include semantic information. Alternatively, these representations may include highly abstract and word-specific semantic information useful for computing phonology but not for more complex semantic tasks.

  10. Further dissociating the processes involved in recognition memory: an FMRI study.

    Science.gov (United States)

    Henson, Richard N A; Hornberger, Michael; Rugg, Michael D

    2005-07-01

    Based on an event-related potential study by Rugg et al. [Dissociation of the neural correlates of implicit and explicit memory. Nature, 392, 595-598, 1998], we attempted to isolate the hemodynamic correlates of recollection, familiarity, and implicit memory within a single verbal recognition memory task using event-related fMRI. Words were randomly cued for either deep or shallow processing, and then intermixed with new words for yes/no recognition. The number of studied words was such that, whereas most were recognized ("hits"), an appreciable number of shallow-studied words were not ("misses"). Comparison of deep hits versus shallow hits at test revealed activations in regions including the left inferior parietal gyrus. Comparison of shallow hits versus shallow misses revealed activations in regions including the bilateral intraparietal sulci, the left posterior middle frontal gyrus, and the left frontopolar cortex. Comparison of hits versus correct rejections revealed a relative deactivation in an anterior left medial-temporal region (most likely the perirhinal cortex). Comparison of shallow misses versus correct rejections did not reveal response decreases in any regions expected on the basis of previous imaging studies of priming. Given these and previous data, we associate the left inferior parietal activation with recollection, the left anterior medial-temporal deactivation with familiarity, and the intraparietal and prefrontal responses with target detection. The absence of differences between shallow misses and correct rejections means that the hemodynamic correlates of implicit memory remain unclear.

  11. The dissociable neural dynamics of cognitive conflict and emotional conflict control: An ERP study.

    Science.gov (United States)

    Xue, Song; Li, Yu; Kong, Xia; He, Qiaolin; Liu, Jia; Qiu, Jiang

    2016-04-21

    This study investigated differences in the neural time-course of cognitive conflict and emotional conflict control, using event-related potentials (ERPs). Although imaging studies have provided some evidence that distinct, dissociable neural systems underlie emotional and nonemotional conflict resolution, no ERP study has directly compared these two types of conflict. Therefore, the present study used a modified face-word Stroop task to explore the electrophysiological correlates of cognitive and emotional conflict control. The behavioral data showed that the difference in response time of congruency (incongruent condition minus the congruent condition) was larger in the cognitive conflict task than in the emotional conflict task, which indicated that cognitive conflict was stronger than the emotional conflict in the present tasks. Analysis of the ERP data revealed a main effect of task type on N2, which may be associated with top-down attention. The N450 results showed an interaction between cognitive and emotional conflict, which might be related to conflict detection. In addition, we found the incongruent condition elicited a larger SP than the congruent condition, which might be related to conflict resolution. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Contribution to simple and double photoionization studies in several molecules excited by synchrotron radiation

    International Nuclear Information System (INIS)

    Lablanquie, Pascal

    1984-01-01

    This work is divided into two parts. Photoelectron spectrometry has enabled us to study the simple photoionisation in inner and outer shell of the N 2 molecule. The limits of an independent particle model, and the importance of electronic interactions have been outlined; an analysis of the structures situated at a photon energy of 23 eV revealed the behavior of two kinds of autoionizing states; the shape resonances of the Σ g + states have been compared. We have then built a new experimental set-up to study double photoionisation. The case of the CS 2 molecule has been examined by mass spectrometry associated to a PIPICO (PhotoIon-PhotoIon Coincidence) technique. An approach of the spectroscopy of the CS 2 ++ ion has been proposed; two dissociation paths of the ion have been observed, their mechanisms are discussed. (author) [fr

  13. Experimental study on the double barrier structure at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, H Y; Chua, S J [Centre for Optoelectronics, Dept. of Electrical Engineering, National Univ. of Singapore (Singapore)

    1994-06-15

    An experimental study of AlAs / GaAs / AlAs double barrier structure is carried out. The double barrier and quantum well structure are grown by MBE. The peak-to-valley ratio 2.6 : 1 with peak current density of 1.6 kA/cm/sup 2 at room temperature have been achieved. (authors)

  14. Functional neuroimaging studies of episodic memory. Functional dissociation in the medial temporal lobe structures

    International Nuclear Information System (INIS)

    Tsukiura, Takashi

    2008-01-01

    Previous functional neuroimaging studies have demonstrated the critical role of the medial temporal lobe (MTL) regions in the encoding and retrieval of episodic memory. It has also been shown that an emotional factor in human memory enhances episodic encoding and retrieval. However, there is little evidence regarding the specific contribution of each MTL region to the relational, contextual, and emotional processes of episodic memory. The goal of this review article is to identify differential activation patterns of the processes between MTL regions. Results from functional neuroimaging studies of episodic memory show that the hippocampus is involved in encoding the relation between memory items, whereas the entorhinal and perirhinal cortices (anterior parahippocampal gyrus) contribute to the encoding of a single item. Additionally, the parahippocampal cortex (posterior parahippocampal gyrus) is selectively activated during the processing of contextual information of episodic memory. A similar pattern of functional dissociation is found in episodic memory retrieval. Functional neuroimaging has also shown that emotional information of episodic memory enhances amygdala-MTL correlations and that this enhancement is observed during both the encoding and retrieval of emotional memories. These findings from pervious neuroimaging studies suggest that different MTL regions could organize memory for personally experienced episodes via the 'relation' and 'context' factors of episodic memory, and that the emotional factor of episodes could modulate the functional organization in the MTL regions. (author)

  15. A Pilot Study of Disparity Vergence and Near Dissociated Phoria in Convergence Insufficiency Patients Before versus After Vergence Therapy

    Directory of Open Access Journals (Sweden)

    Tara L. Alvarez

    2015-07-01

    Full Text Available PURPOSE: This study examined the relationship between the near dissociated phoria and disparity vergence eye movements. Convergence insufficiency (CI patients before vergence therapy were compared to: 1 the same patients after vergence therapy and 2 binocularly normal controls (BNC. METHODS: Sixteen subjects were studied--twelve BNC and four with CI. Measurements from the CI subjects were obtained before and after 18 hours of vergence eye movement therapy. The near dissociated phoria was measured using the flashed Maddox rod technique. Vergence responses were stimulated from 4° symmetrical disparity vergence step stimuli. The peak velocity of the vergence response and the magnitude of the fusion initiating component (FIC from an independent component analysis were calculated. A linear regression analysis was conducted studying the vergence peak velocity as a function of the near dissociated phoria where the Pearson correlation coefficient was computed. RESULTS: Before vergence therapy, the average with one standard deviation FIC magnitude of convergence responses from CI subjects was 0.290.82 and significantly less than the FIC magnitude of 1.850.84 for BNC (p<0.02. A paired t-test reported that the FIC and near dissociated phoria before vergence therapy for CI subjects significantly increased to 1.490.57 (p<0.04 and became less exophoric to 3.5∆1.9 exo (p<0.02 after vergence therapy. A significant correlation (r=0.87; p<0.01 was observed between the near dissociated phoria and the vergence ratio of convergence peak velocity divided by divergence peak velocity. CONCLUSION: The results have clinical translational impact in understanding the mechanism by which vergence therapy may be changing the vergence system leading to a sustained reduction in visual symptoms.

  16. Design studies for the Double Chooz trigger

    International Nuclear Information System (INIS)

    Cucoanes, Andi Sebastian

    2009-01-01

    The main characteristic of the neutrino mixing effect is assumed to be the coupling between the flavor and the mass eigenstates. Three mixing angles (θ 12 , θ 23 , θ 13 ) are describing the magnitude of this effect. Still unknown, θ 13 is considered very small, based on the measurement done by the CHOOZ experiment. A leading experiment will be Double Chooz, placed in the Ardennes region, on the same site as used by CHOOZ. The Double Chooz goal is the exploration of ∝80% from the currently allowed θ 13 region, by searching the disappearance of reactor antineutrinos. Double Chooz will use two similar detectors, located at different distances from the reactor cores: a near one at ∝150 m where no oscillations are expected and a far one at 1.05 km distance, close to the first minimum of the survival probability function. The measurement foresees a precise comparison of neutrino rates and spectra between both detectors. The detection mechanism is based on the inverse β-decay. The Double Chooz detectors have been designed to minimize the rate of random background. In a simplified view, two optically separated regions are considered. The target, filled with Gd-doped liquid scintillator, is the main antineutrino interaction volume. Surrounding the target, the inner veto region aims to tag the cosmogenic muon background which hits the detector. Both regions are viewed by photomultipliers. The Double Chooz trigger system has to be highly efficient for antineutrino events as well as for several types of background. The trigger analyzes discriminated signals from the central region and the inner veto photomultipliers. The trigger logic is fully programmable and can combine the input signals. The trigger conditions are based on the total energy released in event and on the PMT groups multiplicity. For redundancy, two independent trigger boards will be used for the central region, each of them receiving signals from half of the photomultipliers. A third trigger board

  17. Design studies for the Double Chooz trigger

    Energy Technology Data Exchange (ETDEWEB)

    Cucoanes, Andi Sebastian

    2009-07-24

    The main characteristic of the neutrino mixing effect is assumed to be the coupling between the flavor and the mass eigenstates. Three mixing angles ({theta}{sub 12}, {theta}{sub 23}, {theta}{sub 13}) are describing the magnitude of this effect. Still unknown, {theta}{sub 13} is considered very small, based on the measurement done by the CHOOZ experiment. A leading experiment will be Double Chooz, placed in the Ardennes region, on the same site as used by CHOOZ. The Double Chooz goal is the exploration of {proportional_to}80% from the currently allowed {theta}{sub 13} region, by searching the disappearance of reactor antineutrinos. Double Chooz will use two similar detectors, located at different distances from the reactor cores: a near one at {proportional_to}150 m where no oscillations are expected and a far one at 1.05 km distance, close to the first minimum of the survival probability function. The measurement foresees a precise comparison of neutrino rates and spectra between both detectors. The detection mechanism is based on the inverse {beta}-decay. The Double Chooz detectors have been designed to minimize the rate of random background. In a simplified view, two optically separated regions are considered. The target, filled with Gd-doped liquid scintillator, is the main antineutrino interaction volume. Surrounding the target, the inner veto region aims to tag the cosmogenic muon background which hits the detector. Both regions are viewed by photomultipliers. The Double Chooz trigger system has to be highly efficient for antineutrino events as well as for several types of background. The trigger analyzes discriminated signals from the central region and the inner veto photomultipliers. The trigger logic is fully programmable and can combine the input signals. The trigger conditions are based on the total energy released in event and on the PMT groups multiplicity. For redundancy, two independent trigger boards will be used for the central region, each of

  18. DFT study of adsorption and dissociation behavior of H2S on Fe-doped graphene

    International Nuclear Information System (INIS)

    Zhang, Hong-ping; Luo, Xue-gang; Song, Hong-tao; Lin, Xiao-yan; Lu, Xiong; Tang, Youhong

    2014-01-01

    Highlights: • Fe-doped and Pt-doped graphene can significantly improve the interactions between H 2 S and graphene. • The location of S had an important role in the interactions between H 2 S and Fe-doped graphene. • The influence of Fe-S distance can be very weak in a certain range and H 2 S can be dissociated into S and H 2 . - Abstracts: Understanding the interaction mechanisms of hydrogen sulfide (H 2 S) with graphene is important in developing graphene-based sensors for gas detection and removal. In this study, the effects of doped Fe atom on interaction of H 2 S with graphene were investigated by density functional theory calculations. Analyses of adsorption energy, electron density difference, and density of states indicated that the doped Fe atom can significantly improve the interaction of H 2 S gas molecules with graphene, as well as Pt-doped graphene. The location of the sulfur atom is important in the interactions between H 2 S and Fe-doped graphene. The influence of the Fe-S distance can be very weak within a certain distance, as simulated in this study

  19. Molecular dynamics study of CO2 hydrate dissociation: Fluctuation-dissipation and non-equilibrium analysis.

    Science.gov (United States)

    English, Niall J; Clarke, Elaine T

    2013-09-07

    Equilibrium and non-equilibrium molecular dynamics (MD) simulations have been performed to investigate thermal-driven break-up of planar CO2 hydrate interfaces in liquid water at 300-320 K. Different guest compositions, at 85%, 95%, and 100% of maximum theoretical occupation, led to statistically-significant differences in the observed initial dissociation rates. The melting temperatures of each interface were estimated, and dissociation rates were observed to be strongly dependent on temperature, with higher dissociation rates at larger over-temperatures vis-à-vis melting. A simple coupled mass and heat transfer model developed previously was applied to fit the observed dissociation profiles, and this helps to identify clearly two distinct régimes of break-up; a second well-defined region is essentially independent of composition and temperature, in which the remaining nanoscale, de facto two-dimensional system's lattice framework is intrinsically unstable. From equilibrium MD of the two-phase systems at their melting point, the relaxation times of the auto-correlation functions of fluctuations in number of enclathrated guest molecules were used as a basis for comparison of the variation in the underlying, non-equilibrium, thermal-driven dissociation rates via Onsager's hypothesis, and statistically significant differences were found, confirming the value of a fluctuation-dissipation approach in this case.

  20. DFT study of adsorption and dissociation of thiophene molecules on Ni(1 1 0)

    Science.gov (United States)

    Morin, C.; Eichler, A.; Hirschl, R.; Sautet, P.; Hafner, J.

    2003-08-01

    The different adsorption possibilities of thiophene (C 4H 4S) on the Ni(1 1 0) surface have been studied using first principle local-density-functional calculations, with the Vienna ab initio simulation package, which is based on a plane wave basis set and projector augmented wave potentials. For each configuration, a geometric optimisation has been performed. A detailed analysis of the structural and electronic properties of the molecule and the surface in the most stable conformations is presented, showing the combined roles of the molecular distortion and the interactions between the molecule and the surface. Three structures with comparatively large adsorption energies are identified, all with the molecule plane parallel to the surface. Starting from these stabilised structures, various scenarios for the desulfurisation process have been envisaged. While, for the most stable structure, the formation of an adsorbed thiol is an activated process, with an energetic barrier of 0.70 eV, the two structures which are just a bit less stable can dissociate to a C 4H 4 species and a sulfur atom with barriers as low as 0.07 eV. A description of the different transition states and a kinetic analysis of the desulfurisation reaction is also presented.

  1. Dissociable self effects for emotion regulation: a study of Chinese major depressive outpatients.

    Science.gov (United States)

    Wang, Xiaoxia; Feng, Zhengzhi; Zhou, Daiquan; Lei, Xu; Liao, Tongquan; Zhang, Li; Ji, Bing; Li, Jing

    2014-01-01

    Reappraisal is an adaptive emotion regulation strategy while the role of self-perspective in reappraisal process of depressed patients is largely unknown in terms of goals (valence/arousal) and tactics (detachment/immersion). In this study, 12 depressed individuals and 15 controls were scanned with MRI during which they either attend naturally to emotional stimuli, or adopt detachment/immersion strategy. Behaviorally, no group differences in self-reported emotion regulation effectiveness were found. In addition, we observed that (1) patients were less able to downregulate amygdala activation with recruitment of more dorsal lateral prefrontal cortex (dlPFC) when adopting detachment strategy regardless of valence, and this preserved ability to regulate emotion was inversely associated with severity of symptoms; (2) patients had deficits in upregulating amygdala activation when adopting immersion strategy, with less inferior frontal gyrus (IFG) activation and strengthening coupling of dlPFC and ventral medial prefrontal cortex (vmPFC) with amygdala; (3) comparison between groups yielded that patients showed stronger vmPFC activation under either self-detached or self-immersed condition. In conclusion, impaired modulatory effects of amygdala in depressed patients are compensated with strengthening cognitive control resources, with dissociable effects for different self-perspectives in reappraisal. These results may help clarify the role of self-perspective underlying reappraisal in major depression.

  2. Study of DNA Origami Dimerization and Dimer Dissociation Dynamics and of the Factors that Limit Dimerization.

    Science.gov (United States)

    Liber, Miran; Tomov, Toma E; Tsukanov, Roman; Berger, Yaron; Popov, Mary; Khara, Dinesh C; Nir, Eyal

    2018-06-01

    Organizing DNA origami building blocks into higher order structures is essential for fabrication of large structurally and functionally diverse devices and molecular machines. Unfortunately, the yields of origami building block attachment reactions are typically not sufficient to allow programed assembly of DNA devices made from more than a few origami building blocks. To investigate possible reasons for these low yields, a detailed single-molecule fluorescence study of the dynamics of rectangular origami dimerization and origami dimer dissociation reactions is conducted. Reactions kinetics and yields are investigated at different origami and ion concentrations, for different ion types, for different lengths of bridging strands, and for the "sticky end" and "weaving welding" attachment techniques. Dimerization yields are never higher than 86%, which is typical for such systems. Analysis of the dynamic data shows that the low yield cannot be explained by thermodynamic instability or structural imperfections of the origami constructs. Atomic force microscopy and gel electrophoresis evidence reveal self-dimerization of the origami monomers, likely via blunt-end interactions made possible by the presence of bridging strands. It is suggested that this mechanism is the major factor that inhibits correct dimerization and means to overcome it are discussed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Dissociable Self Effects for Emotion Regulation: A Study of Chinese Major Depressive Outpatients

    Directory of Open Access Journals (Sweden)

    Xiaoxia Wang

    2014-01-01

    Full Text Available Reappraisal is an adaptive emotion regulation strategy while the role of self-perspective in reappraisal process of depressed patients is largely unknown in terms of goals (valence/arousal and tactics (detachment/immersion. In this study, 12 depressed individuals and 15 controls were scanned with MRI during which they either attend naturally to emotional stimuli, or adopt detachment/immersion strategy. Behaviorally, no group differences in self-reported emotion regulation effectiveness were found. In addition, we observed that (1 patients were less able to downregulate amygdala activation with recruitment of more dorsal lateral prefrontal cortex (dlPFC when adopting detachment strategy regardless of valence, and this preserved ability to regulate emotion was inversely associated with severity of symptoms; (2 patients had deficits in upregulating amygdala activation when adopting immersion strategy, with less inferior frontal gyrus (IFG activation and strengthening coupling of dlPFC and ventral medial prefrontal cortex (vmPFC with amygdala; (3 comparison between groups yielded that patients showed stronger vmPFC activation under either self-detached or self-immersed condition. In conclusion, impaired modulatory effects of amygdala in depressed patients are compensated with strengthening cognitive control resources, with dissociable effects for different self-perspectives in reappraisal. These results may help clarify the role of self-perspective underlying reappraisal in major depression.

  4. Strong-field dissociation dynamics

    International Nuclear Information System (INIS)

    DiMauro, L.F.; Yang, Baorui.

    1993-01-01

    The strong-field dissociation behavior of diatomic molecules is examined under two distinctive physical scenarios. In the first scenario, the dissociation of the isolated hydrogen and deuterium molecular ions is discussed. The dynamics of above-threshold dissociation (ATD) are investigated over a wide range of green and infrared intensities and compared to a dressed-state model. The second situation arises when strong-field neutral dissociation is followed by ionization of the atomic fragments. The study results in a direct measure of the atomic fragment's ac-Stark shift by observing the intensity-dependent shifts in the electron or nuclear fragment kinetic energy. 8 figs., 14 refs

  5. [Dissociative disorders and affective disorders].

    Science.gov (United States)

    Montant, J; Adida, M; Belzeaux, R; Cermolacce, M; Pringuey, D; Da Fonseca, D; Azorin, J-M

    2014-12-01

    The phenomenology of dissociative disorders may be complex and sometimes confusing. We describe here two cases who were initially misdiagnosed. The first case concerned a 61 year-old woman, who was initially diagnosed as an isolated dissociative fugue and was actually suffering from severe major depressive episode. The second case concerned a 55 year-old man, who was suffering from type I bipolar disorder and polyvascular disease, and was initially diagnosed as dissociative fugue in a mooddestabilization context, while it was finally a stroke. Yet dissociative disorders as affective disorder comorbidity are relatively unknown. We made a review on this topic. Dissociative disorders are often studied through psycho-trauma issues. Litterature is rare on affective illness comorbid with dissociative disorders, but highlight the link between bipolar and dissociative disorders. The later comorbidity often refers to an early onset subtype with also comorbid panic and depersonalization-derealization disorder. Besides, unipolar patients suffering from dissociative symptoms have more often cyclothymic affective temperament. Despite the limits of such studies dissociative symptoms-BD association seems to correspond to a clinical reality and further works on this topic may be warranted. Copyright © 2014 L’Encéphale. Published by Elsevier Masson SAS.. All rights reserved.

  6. A spherical electron cloud hopping model for studying product branching ratios of dissociative recombination.

    Science.gov (United States)

    Yu, Hua-Gen

    2008-05-21

    A spherical electron cloud hopping (SECH) model is proposed to study the product branching ratios of dissociative recombination (DR) of polyatomic systems. In this model, the fast electron-captured process is treated as an instantaneous hopping of a cloud of uniform spherical fractional point charges onto a target M+q ion (or molecule). The sum of point charges (-1) simulates the incident electron. The sphere radius is determined by a critical distance (Rc eM) between the incoming electron (e-) and the target, at which the potential energy of the e(-)-M+q system is equal to that of the electron-captured molecule M+q(-1) in a symmetry-allowed electronic state with the same structure as M(+q). During the hopping procedure, the excess energies of electron association reaction are dispersed in the kinetic energies of M+q(-1) atoms to conserve total energy. The kinetic energies are adjusted by linearly adding atomic momenta in the direction of driving forces induced by the scattering electron. The nuclear dynamics of the resultant M+q(-1) molecule are studied by using a direct ab initio dynamics method on the adiabatic potential energy surface of M+q(-1), or together with extra adiabatic surface(s) of M+q(-1). For the latter case, the "fewest switches" surface hopping algorithm of Tully was adapted to deal with the nonadiabaticity in trajectory propagations. The SECH model has been applied to study the DR of both CH+ and H3O+(H2O)2. The theoretical results are consistent with the experiment. It was found that water molecules play an important role in determining the product branching ratios of the molecular cluster ion.

  7. Fact or Factitious? A Psychobiological Study of Authentic and Simulated Dissociative Identity States

    NARCIS (Netherlands)

    Reinders, A. A. T. Simone; Willemsen, Antoon T. M.; Vos, Herry P. J.; den Boer, Johan A.; Nijenhuis, Ellert R. S.

    2012-01-01

    Background: Dissociative identity disorder (DID) is a disputed psychiatric disorder. Research findings and clinical observations suggest that DID involves an authentic mental disorder related to factors such as traumatization and disrupted attachment. A competing view indicates that DID is due to

  8. Isotope exchange study of the dissociation of metal - humic substance complexes

    Czech Academy of Sciences Publication Activity Database

    Mizera, J.; Jansová, A.; Hvoždová, I.; Beneš, P.; Novák, František

    2003-01-01

    Roč. 53, A (2003), s. A97-A101 ISSN 0011-4626 Institutional research plan: CEZ:AV0Z6066911; CEZ:MSM 210000019 Keywords : isotope exchange * dissociation of metal * humic substance complexes Subject RIV: EH - Ecology, Behaviour Impact factor: 0.263, year: 2003

  9. Study of the 17Ne Coulomb dissociation process and its role for the rp process of nucleosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Marganiec, Justyna [TU Darmstadt (Germany); EMMI, GSI Darmstadt (Germany); Wamers, Felix [EMMI, GSI Darmstadt (Germany); TU Darmstadt (Germany); GSI Darmstadt (Germany); FIAS, Frankfurt am Main (Germany); Aumann, Thomas [TU Darmstadt (Germany); GSI Darmstadt (Germany); Egorova, Irina [BLTP JINR Dubna (Russian Federation); Grigorenko, Leonid [FLNR JINR Dubna (Russian Federation); RRC KI, Moscow (Russian Federation); Heil, Michael [GSI Darmstadt (Germany); Perfenova, Yuliya [FLNR JINR Dubna (Russian Federation); INP, Moscow (Russian Federation); Plag, Ralf [GSI Darmstadt (Germany); Goethe-Universitaet, Frankfurt am Main (Germany); Collaboration: R3B-Collaboration

    2014-07-01

    The study of {sup 17}Ne Coulomb dissociation process gives us a possibility to study the time-reversed reaction {sup 15}O(2p,γ){sup 17}Ne, with the detailed balance theorem. This reaction could serve as a bypass of {sup 15}O waiting point during the rp process, and move the initial CNO material towards heavier nuclei. The two-proton capture can proceed sequentially or directly from the three-body continuum. And the reaction rate can be enhanced by a few orders of magnitude by taking the three-body continuum into account. The Coulomb dissociation method is the one way to experimentally determine the three-body radiative capture cross section, which is needed to verify theoretical calculations, and which was not experimentally determined yet. The experiment has been performed at the LAND/R3B setup at GSI.

  10. Internet addiction: a descriptive clinical study focusing on comorbidities and dissociative symptoms.

    Science.gov (United States)

    Bernardi, Silvia; Pallanti, Stefano

    2009-01-01

    Internet addiction (IAD) is an emerging cause of morbidity and has been recently considered to merit inclusion in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Given the paucity of knowledge about IAD, we conducted a descriptive clinical analysis of patients focusing on clinical, demographic features, and comorbidities. The detachment has been suggested as a reason for the attractiveness of the Internet; thus, we assessed dissociative symptoms and their association with IAD disability. A cohort of 50 adult outpatients were screened using the Internet Addiction Scale. Exclusion criterion was using the Internet for only one purpose such as gaming or gambling. Nine women and 6 men constituted the sample of Internet addicts; each of them had a score of 70 or higher on the Internet Addiction Scale. Comorbidities and subthreshold symptoms were screened carefully. Dissociative symptoms were analyzed with the Dissociative Experience Scale, and disability was assessed using the Sheehan Disability Scale. Hours/week spent on the Internet were 42.21 +/- 3.09. Clinical diagnoses included 14% attention deficit and hyperactivity disorder, 7% hypomania, 15% generalized anxiety disorder, 15% social anxiety disorder; 7% dysthymia, 7% obsessive compulsive personality disorder, 14% borderline personality disorder, and 7% avoidant personality disorder. One patient met criteria for binge eating disorder. Severity measures of IAD were associated with higher perception of family disability (r = 0.814; P Dissociative Experience Scale were higher than expected (23.20 +/- 1.83) and were related to higher obsessive compulsive scores (r = 0.618; P

  11. Performance study of double SOI image sensors

    Science.gov (United States)

    Miyoshi, T.; Arai, Y.; Fujita, Y.; Hamasaki, R.; Hara, K.; Ikegami, Y.; Kurachi, I.; Nishimura, R.; Ono, S.; Tauchi, K.; Tsuboyama, T.; Yamada, M.

    2018-02-01

    Double silicon-on-insulator (DSOI) sensors composed of two thin silicon layers and one thick silicon layer have been developed since 2011. The thick substrate consists of high resistivity silicon with p-n junctions while the thin layers are used as SOI-CMOS circuitry and as shielding to reduce the back-gate effect and crosstalk between the sensor and the circuitry. In 2014, a high-resolution integration-type pixel sensor, INTPIX8, was developed based on the DSOI concept. This device is fabricated using a Czochralski p-type (Cz-p) substrate in contrast to a single SOI (SSOI) device having a single thin silicon layer and a Float Zone p-type (FZ-p) substrate. In the present work, X-ray spectra of both DSOI and SSOI sensors were obtained using an Am-241 radiation source at four gain settings. The gain of the DSOI sensor was found to be approximately three times that of the SSOI device because the coupling capacitance is reduced by the DSOI structure. An X-ray imaging demonstration was also performed and high spatial resolution X-ray images were obtained.

  12. A first principles study of the adsorption and dissociation of CO2 on the δ-Pu (111) surface

    International Nuclear Information System (INIS)

    Atta-Fynn, R.; Raya, A.K.

    2009-01-01

    A complete understanding of the nature of the 5f electrons has been and continues to be a major scientific problem in condensed matter physics. Bulk and surface electronic structure studies of the actinides as also atomic and molecular adsorptions on the actinide surfaces provide a path towards this understanding. In this work, ab initio calculations within the framework of density functional theory have been used to study the adsorption of molecular CO 2 and the corresponding partially dissociated (CO+O) and completely dissociated (C+O+O) products on the δ-Pu (111) surface. The completely dissociated C+O+O configurations exhibit the strongest binding with the surface (7.92 eV), followed by partially dissociated products CO+O (5.08 eV), with molecular CO 2 adsorption having the lowest binding energies (2.35 eV). For all initial vertically upright orientations, the CO 2 molecule physi-sorbs or do not bind to the surface and the geometry and orientation do not change. For all initial flat lying orientations chemisorption occurs, with the final state corresponding to a bent CO 2 molecule with bond angles of 117-130 degrees and the elongation of the CO bond. For CO+O co-adsorption, the stable configurations corresponded to CO dipole moment orientations of 100-172 degrees with respect to the surface normal and the elongation of the CO bond. The most stable chemisorption cases correspond to anomalously large rumpling of the top Pu layer. The interactions of the CO 2 and CO with the Pu surface have been analyzed using the energy density of states and difference charge density distributions. The nature and the behavior of the 5f electrons have also been discussed in detail in the context of this study. (authors)

  13. Dissociative symptoms in kleptomania.

    Science.gov (United States)

    Grant, Jon E

    2004-02-01

    Many patients with kleptomania report an altered state of consciousness during acts of theft. The purpose of this investigation was to clarify a possible link between dissociation and kleptomania, a disabling disorder whose phenomenology remains understudied. 26 adult outpatients who met DSM-IV criteria for kleptoania were administered the Dissociative Experiences Scale and compared to 22 normal controls. The patients with kleptomania had scores that differed significantly from those reported by normal controls. There were no statistically significant differences by sex. Because kleptomania patients seeking treatment with medication may differ from others with kleptomania, further studies are needed.

  14. Opposite brain emotion-regulation patterns in identity states of dissociative identity disorder: a PET study and neurobiological model.

    Science.gov (United States)

    Reinders, Antje A T S; Willemsen, Antoon T M; den Boer, Johan A; Vos, Herry P J; Veltman, Dick J; Loewenstein, Richard J

    2014-09-30

    Imaging studies in posttraumatic stress disorder (PTSD) have shown differing neural network patterns between hypo-aroused/dissociative and hyper-aroused subtypes. Since dissociative identity disorder (DID) involves different emotional states, this study tests whether DID fits aspects of the differing brain-activation patterns in PTSD. While brain activation was monitored using positron emission tomography, DID individuals (n=11) and matched DID-simulating healthy controls (n=16) underwent an autobiographic script-driven imagery paradigm in a hypo-aroused and a hyper-aroused identity state. Results were consistent with those previously found in the two PTSD subtypes for the rostral/dorsal anterior cingulate, the prefrontal cortex, and the amygdala and insula, respectively. Furthermore, the dissociative identity state uniquely activated the posterior association areas and the parahippocampal gyri, whereas the hyper-aroused identity state uniquely activated the caudate nucleus. Therefore, we proposed an extended PTSD-based neurobiological model for emotion modulation in DID: the hypo-aroused identity state activates the prefrontal cortex, cingulate, posterior association areas and parahippocampal gyri, thereby overmodulating emotion regulation; the hyper-aroused identity state activates the amygdala and insula as well as the dorsal striatum, thereby undermodulating emotion regulation. This confirms the notion that DID is related to PTSD as hypo-aroused and hyper-arousal states in DID and PTSD are similar. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  15. Pain sensitivity and neural processing during dissociative states in patients with borderline personality disorder with and without comorbid posttraumatic stress disorder: a pilot study.

    Science.gov (United States)

    Ludäscher, Petra; Valerius, Gabriele; Stiglmayr, Christian; Mauchnik, Jana; Lanius, Ruth A; Bohus, Martin; Schmahl, Christian

    2010-05-01

    Stress-induced dissociative states involving analgesia are a common feature of borderline personality disorder (BPD) and posttraumatic stress disorder (PTSD). Our aim was to investigate the psychologic, somatosensory (pain sensitivity) and neural correlates of dissociative states in patients with these disorders. We included 15 women with BPD who were not taking medication; 10 of these women had comorbid PTSD. While undergoing functional magnetic resonance imaging at 1.5 Tesla, participants were exposed to a script describing a personalized dissociation-inducing situation and a personalized script describing a neutral situation. We assessed dissociative psychopathology and pain sensitivity. Dissociative psychopathology scores were significantly higher and pain sensitivity was lower after the dissociation-inducing script was read compared with the neutral script. The blood oxygen level-dependent (BOLD) signal was significantly increased in the left inferior frontal gyrus (Brodmann area [BA] 9) during the presentation of the dissociation-inducing script. Regression analyses revealed positive correlations between BOLD signal and dissociative psychopathology in the left superior frontal gyrus (BA 6) and negative correlations in the right middle (BA 21) and inferior temporal gyrus (BA 20). In the subgroup of participants with comorbid PTSD, we also found increased activity in the left cingulate gyrus (BA 32) during script-driven imagery-induced dissociation, a positive correlation between dissociation scores and activity in the right and left insula (BA 13) and a negative correlation in the right parahippocampal gyrus (BA 35). The main limitation of this pilot study is the absence of a control group. Therefore, the results may also reflect the neural correlates of non-BPD/PTSD specific dissociative states or the neural correlates of emotionally stressful or "loaded" memories. Another limitation is the uncorrected statistical level of the functional magnetic resonance

  16. A study of laughter and dissociation: distinct correlates of laughter and smiling during bereavement.

    Science.gov (United States)

    Keltner, D; Bonanno, G A

    1997-10-01

    Laughter facilitates the adaptive response to stress by increasing the psychological distance from distress and by enhancing social relations. To test these hypotheses, the authors related measures of bereaved adults' laughter and smiling 6 months postloss to measures of their (a) subjective emotion and dissociation from distress, (b) social relations, and (c) responses they evoked in others. Duchenne laughter, which involves orbicularis oculi muscle action, related to self-reports of reduced anger and increased enjoyment, the dissociation of distress, better social relations, and positive responses from strangers, whereas non-Duchenne laughter did not. Lending credence to speculations in the ethological literature, Duchenne laughter correlated with different intrapersonal and interpersonal responses than Duchenne smiles. Discussion focuses on the relevance of these findings to theories of positive emotion.

  17. Dissociation of metastable CH3CO radicals studied by time-resolved photofragment imaging

    Science.gov (United States)

    Suzuki, Toshinori; Shibata, Takeshi; Li, Haiyang

    1998-05-01

    A novel experimental technique to measure the energy- dependent unimolecular dissociation rate k(E) of radical species is presented. Internally excited CH3CO radicals were formed by ultraviolet photodissociation of CH3COCl, and the subsequent decay of these radicals was detected by subpicosecond time-clocked photofragment imaging. The CH3CO radicals with different internal energies were dispersed in space by their recoil velocities, and their decay rates were measured for each internal energy.

  18. Dissociative symptoms and neuroendocrine dysregulation in depression.

    Science.gov (United States)

    Bob, Petr; Fedor-Freybergh, Peter; Jasova, Denisa; Bizik, Gustav; Susta, Marek; Pavlat, Josef; Zima, Tomas; Benakova, Hana; Raboch, Jiri

    2008-10-01

    Dissociative symptoms are traditionally attributed to psychological stressors that produce dissociated memories related to stressful life events. Dissociative disorders and dissociative symptoms including psychogenic amnesia, fugue, dissociative identity-disorder, depersonalization, derealization and other symptoms or syndromes have been reported as an epidemic psychiatric condition that may be coexistent with various psychiatric diagnoses such as depression, schizophrenia, borderline personality disorder or anxiety disorders. According to recent findings also the somatic components of dissociation may occur and influence brain, autonomic and neuroendocrine functions. At this time there are only few studies examining neuroendocrine response related to dissociative symptoms that suggest significant dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis. The aim of the present study is to perform examination of HPA axis functioning indexed by basal cortisol and prolactin and test their relationship to psychic and somatoform dissociative symptoms. Basal cortisol and prolactin and psychic and somatoform dissociative symptoms were assessed in 40 consecutive inpatients with diagnosis of unipolar depression mean age 43.37 (SD=12.21). The results show that prolactin and cortisol as indices of HPA axis functioning manifest significant relationship to dissociative symptoms. Main results represent highly significant correlations obtained by simple regression between psychic dissociative symptoms (DES) and serum prolactin (R=0.55, p=0.00027), and between somatoform dissociation (SDQ-20) and serum cortisol (R=-0.38, p=0.015). These results indicate relationship between HPA-axis reactivity and dissociative symptoms in unipolar depressive patients that could reflect passive coping behavior and disengagement.

  19. Emission spectroscopic studies on dynamics of molecular excitation and dissociation by controlled electron impact

    International Nuclear Information System (INIS)

    Ogawa, Teiichiro

    1986-01-01

    Emission spectrum by controlled electron impact has been a successful technique for the investigation of molecular dynamics. (1) Molecular excitation. Aromatic molecules give an optical emission similar to fluorescence. However, as is shown by the vibrational structure and the electron energy dependence of benzene emission, its excitation process is not necessarily optical. Some aliphatic molecules also exhibit an emission band at the ultraviolet region. (2) Molecular dissociation. Analysis of the Doppler profile, the threshold energy, the excitation function and the isotope effect of the atomic emission produced in electron-molecule collisions has clarified the dynamics of the molecular dissociation. Especially the Doppler profile has given the translational energy distribution of the fragment atom, which is very useful to disclose the potential energy curve. Its angular dependence has recently found to allow determination of the symmetry of the intermediate excited state and the magnetic sublevel distribution of the fragment atom. These finding has revealed detailed state-to-state dynamics of the molecular dissociation. (author)

  20. Facilities for studying the double beta decay processes

    International Nuclear Information System (INIS)

    Zdesenko, Yu.G.

    1980-01-01

    Modern state, tendencies and perspectiVes of the development of experimental installations to study double β-decay are treated. The main peculiarities of direct recognition and full experiments on the study of double β-decay are considered. A simple ratio is obtained from statistical considerations which connects the life time limits of the nuclei with the facility parameters to conduct direct recognition experiments. Possibilities of different detectors are evaluated on the basis of the ratio. Requirements for the modern technique for complete investigation of double β-decay are formulated and two designs of facilities meeting the requirements are considered. It is shown that the facility with proportional chambers is more perspective. On the basis of the analysis of the facility development to study double β-decay, conclusion is made that the final and unambiguous proof of the existence of double β-decay process can be obtained only directly in the experiments with immediate recording of the decay acts. Possibilities of the existing and developed facilities to conduct recognition (direct) experiments are such, that with their help life time limits as to neutronless double β-decay at the level of 10 21 -10 22 years can be established. Counters on the basis of the condensed noble gases, semiconductor detectors made of TeCd, scintillators of big volume are the most perspective detectors. To conduct complete experiments it is necessary to develop a facility with sensitivity sufficient for the detection of two-neutrino double β-activeness when Tsub(1/2)=10sup(21) years [ru

  1. A nonaqueous potentiometric titration study of the dissociation of t-butyl methacrylate-methacrylic acid copolymers.

    Science.gov (United States)

    Nakatani, Kiyoharu; Yamashita, Jun; Sekine, Tomomi; Toriumi, Minoru; Itani, Toshiro

    2003-05-01

    The dissociation of t-butyl methacrylate-methacrylic acid copolymers in dimethyl sulfoxide was analyzed by a nonaqueous potentiometric titration technique. The negative logarithm of the dissociation constant of the monomer unit of a methacrylic acid (MAA) monotonously increased with the increasing degree of dissociation corresponding to the titrant/MAA amount ratio, and was highly influenced by the copolymerization ratio. The results are discussed in terms of the suppression of the dissociation of MAA by a neighboring charged methacrylate anion unit.

  2. Dissociative part-dependent biopsychosocial reactions to backward masked angry and neutral faces: An fMRI study of dissociative identity disorder.

    Science.gov (United States)

    Schlumpf, Yolanda R; Nijenhuis, Ellert R S; Chalavi, Sima; Weder, Ekaterina V; Zimmermann, Eva; Luechinger, Roger; La Marca, Roberto; Reinders, A A T Simone; Jäncke, Lutz

    2013-01-01

    The Theory of Structural Dissociation of the Personality (TSDP) proposes that dissociative identity disorder (DID) patients are fixed in traumatic memories as "Emotional Parts" (EP), but mentally avoid these as "Apparently Normal Parts" of the personality (ANP). We tested the hypotheses that ANP and EP have different biopsychosocial reactions to subliminally presented angry and neutral faces, and that actors instructed and motivated to simulate ANP and EP react differently. Women with DID and matched healthy female actors (CON) were as ANP and EP (DIDanp, DIDep, CONanp, CONep) consecutively exposed to masked neutral and angry faces. Their brain activation was monitored using functional magnetic resonance imaging. The black-and-white dotted masks preceding and following the faces each had a centered colored dot, but in a different color. Participants were instructed to immediately press a button after a perceived color change. State anxiety was assessed after each run using the STAI-S. Final statistical analyses were conducted on 11 DID patients and 15 controls for differences in neural activity, and 13 DID patients and 15 controls for differences in behavior and psychometric measures. Differences between ANP and EP in DID patients and between DID and CON in the two dissociative parts of the personality were generally larger for neutral than for angry faces. The longest reaction times (RTs) existed for DIDep when exposed to neutral faces. Compared to DIDanp, DIDep was associated with more activation of the parahippocampal gyrus. Following neutral faces and compared to CONep, DIDep had more activation in the brainstem, face-sensitive regions, and motor-related areas. DIDanp showed a decreased activity all over the brain in the neutral and angry face condition. There were neither significant within differences nor significant between group differences in state anxiety. CON was not able to simulate genuine ANP and EP biopsychosocially. DID patients have dissociative

  3. Dissociative part-dependent biopsychosocial reactions to backward masked angry and neutral faces: An fMRI study of dissociative identity disorder☆

    Science.gov (United States)

    Schlumpf, Yolanda R.; Nijenhuis, Ellert R.S.; Chalavi, Sima; Weder, Ekaterina V.; Zimmermann, Eva; Luechinger, Roger; La Marca, Roberto; Reinders, A.A.T. Simone; Jäncke, Lutz

    2013-01-01

    Objective The Theory of Structural Dissociation of the Personality (TSDP) proposes that dissociative identity disorder (DID) patients are fixed in traumatic memories as “Emotional Parts” (EP), but mentally avoid these as “Apparently Normal Parts” of the personality (ANP). We tested the hypotheses that ANP and EP have different biopsychosocial reactions to subliminally presented angry and neutral faces, and that actors instructed and motivated to simulate ANP and EP react differently. Methods Women with DID and matched healthy female actors (CON) were as ANP and EP (DIDanp, DIDep, CONanp, CONep) consecutively exposed to masked neutral and angry faces. Their brain activation was monitored using functional magnetic resonance imaging. The black-and-white dotted masks preceding and following the faces each had a centered colored dot, but in a different color. Participants were instructed to immediately press a button after a perceived color change. State anxiety was assessed after each run using the STAI-S. Final statistical analyses were conducted on 11 DID patients and 15 controls for differences in neural activity, and 13 DID patients and 15 controls for differences in behavior and psychometric measures. Results Differences between ANP and EP in DID patients and between DID and CON in the two dissociative parts of the personality were generally larger for neutral than for angry faces. The longest reaction times (RTs) existed for DIDep when exposed to neutral faces. Compared to DIDanp, DIDep was associated with more activation of the parahippocampal gyrus. Following neutral faces and compared to CONep, DIDep had more activation in the brainstem, face-sensitive regions, and motor-related areas. DIDanp showed a decreased activity all over the brain in the neutral and angry face condition. There were neither significant within differences nor significant between group differences in state anxiety. CON was not able to simulate genuine ANP and EP biopsychosocially

  4. Multireference configuration interaction treatment of potential energy surfaces: symmetric dissociation of H/sub 2/O in a double-zeta basis

    Energy Technology Data Exchange (ETDEWEB)

    Brown, F B; Shavitt, I; Shepard, R

    1984-03-23

    Multiconfiguration self-consistent fields (SCF) and multireference configurational interaction (CI) calculations have been performed for the H/sub 2/O molecule in a double-zeta basis for four symmetric geometries, for comparison with full CI results. Unlike single-reference results, the energy errors are almost independent of geometry, allowing unbiased treatments of potential energy surfaces. 35 references, 1 figure, 2 tables.

  5. Studies on the photochemical and thermal dissociation synthesis of krypton difluoride

    Energy Technology Data Exchange (ETDEWEB)

    Kinkead, S.A.; FitzPatrick, J.R.; Foropoulos, J. Jr.; Kissane, R.J.; Purson, J.D.

    1993-08-01

    Like dioxygen difluoride (O{sub 2}F{sub 2}), KrF{sub 2} can be produced by thermal dissociation or photochemical synthesis from the elements; however, the yields are invariably much less than those obtained for O{sub 2}F{sub 2}. For example, while irradiation of liquid O{sub 2}/F{sub 2} mixtures at {minus}196{degrees}C through a sapphire window with an unfiltered 1,000W uv lamp provides in excess of 3g of O{sub 2}F{sub 2} per hour, the yield of KrF{sub 2} under identical circumstances is approximately 125 mg/hr. In this report, the yield of KrF{sub 2} in quartz and Pyrex{trademark} photochemical reactors has been examined as a function of irradiation wavelength, irradiation power, and Kr: F{sub 2} mole ratio. The uv-visible spectrum of KrF{sub 2} has also been recorded for comparison with earlier work, and the quantum yield for photodissociation at two wavelengths determined. The synthesis of KrF{sub 2} using large thermal gradients has also been examined using resistively heated nickel filaments to thermally dissociate the F{sub 2} in close proximity to liquid nitrogen-cooled metal surfaces. As a net result, KrF{sub 2} has been produced in yields in excess of 1.75 g/hr for extended periods in photochemical systems, and 2.3 g/hr for shorter periods in thermally dissociative reactors. This paper summarizes the results of examining parametrically several different types of reactors for efficiency of producing krypton difluoride.

  6. Molecular beam study of dissociative sticking of methane on Ni(100)

    DEFF Research Database (Denmark)

    Holmblad, Peter Mikal; Wambach, Jørg; Chorkendorff, Ib

    1995-01-01

    of the methane leads to a dramatic enhancement of the sticking, emphasizing that the initial vibrational state is of crucial importance. These results are consistent with a mechanism of direct activated dissociative chemisorption where the dynamics is dominated by a barrier in the potential energy surface mainly...... located in the vibrational coordinates. Normal-energy scaling is only approximately observed. The effect of surface temperature is also investigated but is found to be smaller than activation by translational or vibrational energy. A simplified analysis in terms of state resolved sticking curves, Snu...... American Institute of Physics....

  7. Stability and dissociation dynamics of N{sub 2}{sup ++} ions following core ionization studied by an Auger-electron–photoion coincidence method

    Energy Technology Data Exchange (ETDEWEB)

    Iwayama, H.; Shigemasa, E. [UVSOR Facility, Institute for Molecular Science, Nishigonaka 38, Myodaiji, Okazaki 444-8585 (Japan); SOKENDAI, Nishigonaka 38, Myodaiji, Okazaki 444-8585 (Japan); Kaneyasu, T. [SAGA Light Source, Tosu 841-0005 (Japan); Hikosaka, Y. [Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194 (Japan)

    2016-07-21

    An Auger-electron–photoion coincidence (AEPICO) method has been applied to study the stability and dissociation dynamics of dicationic states after the N K-shell photoionization of nitrogen molecules. From time-of-flight and kinetic energy analyses of the product ions, we have obtained coincident Auger spectra associated with metastable states of N{sub 2}{sup ++} ions and dissociative states leading to N{sub 2}{sup ++} → N{sup +} + N{sup +} and N{sup ++} + N. To investigate the production of dissociative states, we present two-dimensional AEPICO maps which reveal the correlations between the binding energies of the Auger final states and the ion kinetic energy release. These correlations have been used to determine the dissociation limits of individual Auger final states.

  8. Theoretical study on the cooperative exciton dissociation process based on dimensional and hot charge-transfer state effects in an organic photocell

    International Nuclear Information System (INIS)

    Shimazaki, Tomomi; Nakajima, Takahito

    2016-01-01

    This paper discusses the exciton dissociation process at the donor–acceptor interface in organic photocells. In our previous study, we introduced a local temperature to handle the hot charge-transfer (CT) state and calculated the exciton dissociation probability based on the 1D organic semiconductor model [T. Shimazaki and T. Nakajima, Phys. Chem. Chem. Phys. 17, 12538 (2015)]. Although the hot CT state plays an essential role in exciton dissociations, the probabilities calculated are not high enough to efficiently separate bound electron–hole pairs. This paper focuses on the dimensional (entropy) effect together with the hot CT state effect and shows that cooperative behavior between both effects can improve the exciton dissociation process. In addition, we discuss cooperative effects with site-disorders and external-electric-fields.

  9. Radiation Protection, double-blind studies with radiopharmaceuticals

    International Nuclear Information System (INIS)

    Pujadas, M. C.; Camacho, C.; Guasp, M.; Villaescusa, J. I.

    2009-01-01

    In a double-blind randomized controlled clinical trial (RCT) subjects and researchers do not know the assignment to treatment groups to ovoid the appearance of subjective biases of information. The employment of radiopharmaceuticals in double-blind RCTs raises a dilemma from the point ov view of the radiological protection. On the one hand, the obligation to act in cases of contamination and/or risk of irradiation exists, but on the other hand the duty of keeping the blind study also exists. In this paper some of the possible problems that arise when conducting a double-blind RCT with radiopharmaceuticals from the point of view of the radiological protection are presented. We comment our experience with the radiopharmaceutical Alpharadin and, in addition, we propose useful recommendations based on the randomness of the decontamination process. (Author) 7 refs.

  10. Double resonance spectroscopy of the D1Πu+ and B′′ B-bar 1Σu+ states near the third dissociation threshold of H2

    International Nuclear Information System (INIS)

    Ekey, R C; Cordova, A E; Duan, W; Chartrand, A M; McCormack, E F

    2013-01-01

    Double-resonance laser spectroscopy via the E,F 1 Σ g + ,v ′ =6,J ′ state was used to probe the energy region below the third dissociation limit of molecular hydrogen. Resonantly enhanced multi-photon ionization spectra were recorded by detecting ion production as a function of energy using a time-of-flight mass spectrometer. Energies and line widths for the v = 14–17 levels of the D 1 Π u + state of H 2 are reported and compared to experimental data obtained by using VUV synchrotron light excitation (Dickenson et al 2010 J. Chem. Phys. 133 144317) and fully ab initio non-adiabatic calculations of D 1 Π u + state energies and line widths (Glass-Maujean et al 2012 Phys. Rev. A 86 052507). Several high vibrational levels of the B ′′ B-bar 1 Σ u + state were also observed in this region. Term energies and rotational constants for the v = 67–69 vibrational levels are reported and compared to highly accurate ro-vibrational energy level predictions from fully ab initio non-adiabatic calculations of the first six 1 Σ u + levels of H 2 (Wolniewicz et al 2006 J. Mol. Spectrosc. 238 118). While additional observed transitions can be assigned to other states, several unassigned features in the spectra highlight the need for a fully integrated theoretical treatment of dissociation and ionization to understand the complex pattern of highly vibrationally excited states expected in this region. (paper)

  11. Theoretical studies of molecule surface scattering: Rotationally inelastic diffraction and dissociative dynamics of H2 on metals

    International Nuclear Information System (INIS)

    Cruz Pol, A.J.

    1993-01-01

    The interaction of H 2 and its isotopes with metal surfaces has been the subject of many investigations. The scattering experiments provide data such as the final rotational state distribution, sticking coefficients, kinetic energy distribution, and diffraction data. In the first study of this thesis the author implemented a model for looking at the rotationally inelastic diffraction probabilities for H 2 , HD, and D 2 , as a function of surface temperature. The surface is treated in a quantum mechanical fashion using a recently developed formalism. The center of mass translational motion is treated semiclassically using Gaussian wave packets, and the rotations are described quantum mechanically. The phonon summed rotation-diffraction probabilities as well as the probability distribution for a scattering molecule exchanging an amount of energy ΔE with the surface were computed. In the second and third study of this thesis the author implemented a mixed quantum-classical model to compute the probability for dissociation and rotational excitation for H 2 , HD, and D 2 scattered from Ni(100) dimensionally in dynamics simulations. Of the six degrees of freedom for the dissociative adsorption of a diatomic molecule on a static surface, the author treats Z,d the center of mass distance above the surface plan, r, the internuclear separation, θ, the polar orientation angle, quantum mechanically. The remaining three degrees of freedom, X and Y, the center of mass position on the surface plane, and oe, the azimuthal orientation angle, are treated classically. Probabilities for dissociation and ro-vibrational excitation are computed as a function of incident translational energy. Two sudden approximations are tested, in which either the center of mass translation parallel to the surface or the azimuthal orientation of the molecule are frozen. Comparisons are made between low and high dimensionality results and with fully classical results

  12. Study of interference by double neutron capture in activation analysis

    International Nuclear Information System (INIS)

    Cohen, I.M.; Korob, R.O.; Mila, M.I.; Rocca, H.C.

    1976-06-01

    The characteristics of the interferences by double capture in activation analysis are studied. Calculations of these interferences are performed, based on the corresponding activation functions, for typical irradiation and decay times. The experiments performed with the pairs Ho-Dy and Pt-Au and their results are commented. (author) [es

  13. randomised double blind study to compare effectiveness of honey

    African Journals Online (AJOL)

    2014-02-02

    Feb 2, 2014 ... EAsT AFRICAN MEDICAL JOURNAL. February 2014 .... based randomised double- blinded clinical trial evaluating effectiveness of ... study drugs was undertaken following a random ... included sodium citrate, citric acid monohydrate, ... post-hoc test to carry out pair-wise comparisons of .... self-care market.

  14. Fragmentation study of iridoid glucosides through positive and negative electrospray ionization, collision-induced dissociation and tandem mass spectrometry.

    Science.gov (United States)

    Es-Safi, Nour-Eddine; Kerhoas, Lucien; Ducrot, Paul-Henri

    2007-01-01

    Mass spectrometric methodology based on the combined use of positive and negative electrospray ionization, collision-induced dissociation (CID) and tandem mass spectrometry (MS/MS) has been applied to the mass spectral study of a series of six naturally occurring iridoids through in-source fragmentation of the protonated [M+H]+, deprotonated [M--H]- and sodiated [M+Na]+ ions. This led to the unambiguous determination of the molecular masses of the studied compounds and allowed CID spectra of the molecular ions to be obtained. Valuable structural information regarding the nature of both the glycoside and the aglycone moiety was thus obtained. Glycosidic cleavage and ring cleavages of both aglycone and sugar moieties were the major fragmentation pathways observed during CID, where the losses of small molecules, the cinnamoyl and the cinnamate parts were also observed. The formation of the ionized aglycones, sugars and their product ions was thus obtained giving information on their basic skeleton. The protonated, i.e. [M+H]+ and deprotonated [M--H]-, ions were found to fragment mainly by glycosidic cleavages. MS/MS spectra of the [M+Na]+ ions gave complementary information for the structural characterization of the studied compounds. Unlike the dissociation of protonated molecular ions, that of sodiated molecules also provided sodiated sugar fragments where the C0+ fragment corresponding to the glucose ion was obtained as base peak for all the studied compounds. Copyright (c) 2007 John Wiley & Sons, Ltd.

  15. Dissociative photoionization of the NO molecule studied by photoelectron-photon coincidence technique

    International Nuclear Information System (INIS)

    Kivimaeki, A.; Alvarez-Ruiz, J.; Coreno, M.; Simone, M. de; Moise, A.; Partanen, L.; Richter, R.; Stankiewicz, M.

    2010-01-01

    Low-energy photoelectron-vacuum ultraviolet (VUV) photon coincidences have been measured using synchrotron radiation excitation in the inner-valence region of the nitric oxide molecule. The capabilities of the coincidence set-up were demonstrated by detecting the 2s -1 → 2p -1 radiative transitions in coincidence with the 2s photoelectron emission in Ne. In NO, the observed coincidence events are attributed to dissociative photoionization with excitation, whereby photoelectron emission is followed by fragmentation of excited NO + ions into O + + N* or N + + O* and VUV emission from an excited neutral fragment. The highest coincidence rate occurs with the opening of ionization channels which are due to correlation satellites of the 3σ photoionization. The decay time of VUV photon emission was also measured, implying that specific excited states of N atoms contribute significantly to observed VUV emission.

  16. Voluntary switching between identities in dissociative identity disorder: A functional MRI case study.

    Science.gov (United States)

    Savoy, R L; Frederick, B B; Keuroghlian, A S; Wolk, P C

    2012-01-01

    Patients who suffer from dissociative identity disorder present unique scientific and clinical challenges for psychology and psychiatry. We have been fortunate in working with a patient who-while undergoing functional MRI-can switch rapidly and voluntarily between her main personality (a middle-aged, high-functioning woman) and an alternate personality (a 4-6-year-old girl). A unique task was designed to isolate the processes occurring during the switches between these personalities. Data are from two imaging sessions, conducted months apart, each showing the same activated areas during switches between these personalities. The activated areas include the following: the primary sensory and motor cortex, likely associated with characteristic facial movements made during switching; the nucleus accumbens bilaterally, possibly associated with aspects of reward connected with switching; and prefrontal sites, presumably associated with the executive control involved in the switching of personalities.

  17. Dissociative symptomatology in cancer patients

    Science.gov (United States)

    Civilotti, Cristina; Castelli, Lorys; Binaschi, Luca; Cussino, Martina; Tesio, Valentina; Di Fini, Giulia; Veglia, Fabio; Torta, Riccardo

    2015-01-01

    Introduction: The utilization of the post-traumatic stress disorder (PTSD) diagnostic spectrum is currently being debated to categorize psychological adjustment in cancer patients. The aims of this study were to: (1) evaluate the presence of cancer-related traumatic dissociative symptomatology in a sample of cancer patients; (2) examine the correlation of cancer-related dissociation and sociodemographic and medical variables, anxiety, depression, and post-traumatic stress symptomatology; (3) investigate the predictors of cancer-related dissociation. Methods: Ninety-two mixed cancer patients (mean age: 58.94, ds = 10.13) recruited from two hospitals in northern Italy were administered a questionnaire on sociodemographic and medical characteristics, the Karnofsky Scale to measure the level of patient activity and medical care requirements, the Hospital Anxiety and Depression Scale (HADS) to evaluate the presence of anxiety and depression, the Impact of Event Scale Revised (IES-R) to assess the severity of intrusion, avoidance, and hypervigilance, and the Peritraumatic Dissociative Experiences Questionnaire (PDEQ) to quantify the traumatic dissociative symptomatology. Results: 31.5% of participants report a PDEQ score above the cutoff. The results indicated that dissociative symptomatology was positively correlated with HADS scores (HADS-Anxiety: r = 0.476, p dissociative symptomatology. The results converged on a three predictor model revealing that IES-R-Intrusion, IES-R-Avoidance, and IES-R-Hyperarousal accounted for 53.9% of the explained variance. Conclusion: These findings allow us to hypothesize a specific psychological reaction which may be ascribed to the traumatic spectrum within the context of cancer, emphasizing the close relationship between the origin of dissociative constituents which, according to the scientific literature, compose the traumatic experience. Our results have implications for understanding dissociative symptomatology in a cancer

  18. Study on the calibration and optimization of double theodolites baseline

    Science.gov (United States)

    Ma, Jing-yi; Ni, Jin-ping; Wu, Zhi-chao

    2018-01-01

    For the double theodolites measurement system baseline as the benchmark of the scale of the measurement system and affect the accuracy of the system, this paper puts forward a method for calibration and optimization of the double theodolites baseline. Using double theodolites to measure the known length of the reference ruler, and then reverse the baseline formula. Based on the error propagation law, the analyses show that the baseline error function is an important index to measure the accuracy of the system, and the reference ruler position, posture and so on have an impact on the baseline error. The optimization model is established and the baseline error function is used as the objective function, and optimizes the position and posture of the reference ruler. The simulation results show that the height of the reference ruler has no effect on the baseline error; the posture is not uniform; when the reference ruler is placed at x=500mm and y=1000mm in the measurement space, the baseline error is the smallest. The experimental results show that the experimental results are consistent with the theoretical analyses in the measurement space. In this paper, based on the study of the placement of the reference ruler, for improving the accuracy of the double theodolites measurement system has a reference value.

  19. Aspartame Sensitivity? A Double Blind Randomised Crossover Study

    OpenAIRE

    Sathyapalan, Thozhukat; Thatcher, Natalie J.; Hammersley, Richard; Rigby, Alan S.; Pechlivanis, Alexandros; Gooderham, Nigel J.; Holmes, Elaine; le Roux, Carel W.; Atkin, Stephen L.; Courts, Fraser

    2015-01-01

    Background Aspartame is a commonly used intense artificial sweetener, being approximately 200 times sweeter than sucrose. There have been concerns over aspartame since approval in the 1980s including a large anecdotal database reporting severe symptoms. The objective of this study was to compare the acute symptom effects of aspartame to a control preparation. Methods This was a double-blind randomized cross over study conducted in a clinical research unit in United Kingdom. Forty-eight indivi...

  20. Encoding-related brain activity dissociates between the recollective processes underlying successful recall and recognition: a subsequent-memory study.

    Science.gov (United States)

    Sadeh, Talya; Maril, Anat; Goshen-Gottstein, Yonatan

    2012-07-01

    The subsequent-memory (SM) paradigm uncovers brain mechanisms that are associated with mnemonic activity during encoding by measuring participants' neural activity during encoding and classifying the encoding trials according to performance in the subsequent retrieval phase. The majority of these studies have converged on the notion that the mechanism supporting recognition is mediated by familiarity and recollection. The process of recollection is often assumed to be a recall-like process, implying that the active search for the memory trace is similar, if not identical, for recall and recognition. Here we challenge this assumption and hypothesize - based on previous findings obtained in our lab - that the recollective processes underlying recall and recognition might show dissociative patterns of encoding-related brain activity. To this end, our design controlled for familiarity, thereby focusing on contextual, recollective processes. We found evidence for dissociative neurocognitive encoding mechanisms supporting subsequent-recall and subsequent-recognition. Specifically, the contrast of subsequent-recognition versus subsequent-recall revealed activation in the Parahippocampal cortex (PHc) and the posterior hippocampus--regions associated with contextual processing. Implications of our findings and their relation to current cognitive models of recollection are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Dissociative symptoms and dissociative disorder comorbidity in patients with obsessive-compulsive disorder.

    Science.gov (United States)

    Belli, Hasan; Ural, Cenk; Vardar, Melek Kanarya; Yesılyurt, Sema; Oncu, Fatıh

    2012-10-01

    The present study attempted to assess the dissociative symptoms and overall dissociative disorder comorbidity in patients with obsessive-compulsive disorder (OCD). In addition, we examined the relationship between the severity of obsessive-compulsive symptoms and dissociative symptoms. All patients admitted for the first time to the psychiatric outpatient unit were included in the study. Seventy-eight patients had been diagnosed as having OCD during the 2-year study period. Patients had to meet the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for OCD. Most (76.9%; n = 60) of the patients were female, and 23.1% (n = 18) of the patients were male. Dissociation Questionnaire was used to measure dissociative symptoms. The Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Dissociative Disorders interviews and Yale-Brown Obsessive Compulsive Checklist and Severity Scale were used. Eleven (14%) of the patients with OCD had comorbid dissociative disorder. The most prevalent disorder in our study was dissociative depersonalization disorder. Dissociative amnesia and dissociative identity disorder were common as well. The mean Yale-Brown score was 23.37 ± 7.27 points. Dissociation Questionnaire scores were between 0.40 and 3.87 points, and the mean was 2.23 ± 0.76 points. There was a statistically significant positive correlation between Yale-Brown points and Dissociation Questionnaire points. We conclude that dissociative symptoms among patients with OCD should alert clinicians for the presence of a chronic and complex dissociative disorder. Clinicians may overlook an underlying dissociative process in patients who have severe symptoms of OCD. However, a lack of adequate response to cognitive-behavioral and drug therapy may be a consequence of dissociative process. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Dissociation Energies of Diatomic Molecules

    International Nuclear Information System (INIS)

    Qun-Chao, Fan; Wei-Guo, Sun

    2008-01-01

    Molecular dissociation energies of 10 electronic states of alkali molecules of KH, 7 LiD, 7 LiH, 6 LiH, NaK, NaLi and NaRb are studied using the highest three accurate vibrational energies of each electronic state, and an improved parameter-free analytical formula which is obtained starting from the LeRoy–Bernstein vibrational energy expression near the dissociation limit. The results show that as long as the highest three vibrational energies are accurate, the current analytical formula will give accurate theoretical dissociation energies D e theory , which are in excellent agreement with the experimental dissociation energies D e expt . (atomic and molecular physics)

  3. Dissociative Tendencies and Traffic Incidents

    Directory of Open Access Journals (Sweden)

    Valle, Virginia

    2012-01-01

    Full Text Available This paper analyses the relationship between dissociative experiences and road traffic incidents (crashes and traffic tickets in drivers (n=295 from Mar del Plata (Argentina city. A self-report questionnaire was applied to assess traffic crash involvement and sociodemographic variables. Dissociative tendencies were assessed by a modified version of the DES scale. To examine differences in DES scores tests of the difference of means were applied. Drivers who reported to be previously involved in traffic incidents obtained higher puntuations in the dissociative experiences scale than drivers who did not report such events. This result is observed for the total scale and for the three sub-scales (absorption, amnesia and depersonalization. However, differences appeared mainly for minor damage collisions. Further studies are needed to evaluate the role of dissociative tendencies as a risk factor in road traffic safety.

  4. Double contrast study of the operated stomach in lateroposition

    International Nuclear Information System (INIS)

    Volodina, G.I.; Novakovskij, A.R.

    1986-01-01

    Anastomosis was diagnosed in 34 patients, anastomosis ulcer in 3, cancer of the stump in 2, recurrence of stomach polyposis in 1 and cicatrical structure of the jejunum in 1. The great potentialities of a double contrast study of the operated stomach in lateroposition in the differential diagnosis of cancer of the stomach stump, deformities and other diseases were noted. The above method of examination of the operated stomach was recommended as an adjuvant to the commonly used method

  5. Evidence of the dissociative PTSD subtype: A systematic literature review of latent class and profile analytic studies of PTSD.

    Science.gov (United States)

    Hansen, Maj; Ross, Jana; Armour, Cherie

    2017-04-15

    The dissociative PTSD (D-PTSD) subtype was first introduced into the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) in 2013. Prior to this, studies using latent profile analysis (LPA) or latent class analysis (LCA), began to provide support for the D-PTSD construct and associated risk factors. This research is important, because dissociative symptoms in the context of PTSD may potentially interfere with treatment course or outcome. The aims of the present study were twofold: to systematically review the LCA and LPA studies investigating support for the D-PTSD construct; and to review the associated research on the risk factors or covariates of D-PTSD in the identified studies. Six databases (PubMed, Web of Science, Scopus, PILOTS, PsychInfo, and Embase) were systematically searched for relevant papers. Eleven studies were included in the present review. The majority of the studies were supportive of the D-PTSD subtype; primarily characterized by depersonalization and derealization. Several covariates of the D-PTSD subtype have been investigated with mixed results. Many limitations relate to the state of the current literature, including a small number of studies, the use of self-report measurements of PTSD, and heterogeneity across the samples in investigated covariates. The results were overall supportive of the D-PTSD construct. Future research on D-PTSD and associated risk factors is needed to shed light on the possibilities of facilitating preventive actions, screening, and implications on treatment effects. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Propofol and memory: a study using a process dissociation procedure and functional magnetic resonance imaging.

    Science.gov (United States)

    Quan, X; Yi, J; Ye, T H; Tian, S Y; Zou, L; Yu, X R; Huang, Y G

    2013-04-01

    Thirty volunteers randomly received either mild or deep propofol sedation, to assess its effect on explicit and implicit memory. Blood oxygen level-dependent functional magnetic resonance during sedation examined brain activation by auditory word stimulus and a process dissociation procedure was performed 4 h after scanning. Explicit memory formation did not occur in either group. Implicit memories were formed during mild but not deep sedation (p = 0.04). Mild propofol sedation inhibited superior temporal gyrus activation (Z value 4.37, voxel 167). Deep propofol sedation inhibited superior temporal gyrus (Z value 4.25, voxel 351), middle temporal gyrus (Z value 4.39, voxel 351) and inferior parietal lobule (Z value 5.06, voxel 239) activation. Propofol only abolishes implicit memory during deep sedation. The superior temporal gyrus is associated with explicit memory processing, while the formation of both implicit and explicit memories is associated with superior and middle temporal gyri and inferior parietal lobule activation. Anaesthesia © 2013 The Association of Anaesthetists of Great Britain and Ireland.

  7. Water dissociation and CO oxidation over Au/anatase catalyst. A DFT-D2 study

    Science.gov (United States)

    Saqlain, Muhammad Adnan; Hussain, Akhtar; Siddiq, Muhammad; Leitão, Alexandre A.

    2018-03-01

    With the help of DFT-D2 methodology, we have investigated the adsorption of water on clean anatase(001) and Au/anatase(001). In the former case, adsorption energies of H2O differ to small extent computed employing GGA = PW91 and DFT-D2 methods. While the GGA = PW91 predicts that water would desorb close to 650 K on the TiO2 surface, the DFT-D2 predicts that desorption is most likely to occur above 700 K. A comparison of water adsorption on TiO2 and Au/TiO2 surfaces shows that the TiO2 prefers dimer adsorption whereas the Au/TiO2 prefers monomer adsorption. We found that the diffusion of surface hydroxyls on to the Au cluster from the Au/TiO2 periphery is unlikely and it seems that the CO oxidation would occur at the Au/TiO2 boundary. The results show that water dissociation and CO oxidation steps occur easily on Au/TiO2 indicating that this could be good alternative catalyst for water gas shift reaction industry.

  8. IR and visible luminescence studies in the infrared multiphoton dissociation of 1,2-dibromo-1,1-difluoroethane

    Science.gov (United States)

    Pushpa, K. K.; Kumar, Awadhesh; Vatsa, R. K.; Naik, P. D.; Annaji Rao, K.; Mittal, J. P.; Parthasarathy, V.; Sarkar, S. K.

    1995-07-01

    The infrared multiphoton dissociation of 1,2-dibromo-1,1-difluoroethane gives rise to IR and visible luminescence. Vibrationally excited parent molecules dissociate via two primary channels yielding bromine and vibrationally excited HBr. The strong visible emission observed between 350 to 750 nm has been assigned to electronically excited carbene CF 2Br CH.

  9. Dissociation in patients with dissociative seizures: relationships with trauma and seizure symptoms.

    Science.gov (United States)

    Pick, S; Mellers, J D C; Goldstein, L H

    2017-05-01

    This study aimed to extend the current understanding of dissociative symptoms experienced by patients with dissociative (psychogenic, non-epileptic) seizures (DS), including psychological and somatoform types of symptomatology. An additional aim was to assess possible relationships between dissociation, traumatic experiences, post-traumatic symptoms and seizure manifestations in this group. A total of 40 patients with DS were compared with a healthy control group (n = 43), matched on relevant demographic characteristics. Participants completed several self-report questionnaires, including the Multiscale Dissociation Inventory (MDI), Somatoform Dissociation Questionnaire-20, Traumatic Experiences Checklist and the Post-Traumatic Diagnostic Scale. Measures of seizure symptoms and current emotional distress (Hospital Anxiety and Depression Scale) were also administered. The clinical group reported significantly more psychological and somatoform dissociative symptoms, trauma, perceived impact of trauma, and post-traumatic symptoms than controls. Some dissociative symptoms (i.e. MDI disengagement, MDI depersonalization, MDI derealization, MDI memory disturbance, and somatoform dissociation scores) were elevated even after controlling for emotional distress; MDI depersonalization scores correlated positively with trauma scores while seizure symptoms correlated with MDI depersonalization, derealization and identity dissociation scores. Exploratory analyses indicated that somatoform dissociation specifically mediated the relationship between reported sexual abuse and DS diagnosis, along with depressive symptoms. A range of psychological and somatoform dissociative symptoms, traumatic experiences and post-traumatic symptoms are elevated in patients with DS relative to healthy controls, and seem related to seizure manifestations. Further studies are needed to explore peri-ictal dissociative experiences in more detail.

  10. Dissociation dynamics of methylal

    Energy Technology Data Exchange (ETDEWEB)

    Beaud, P; Frey, H -M; Gerber, T; Mischler, B; Radi, P P; Tzannis, A -P [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The dissociation of methylal is investigated using mass spectrometry, combined with a pyrolytic radical source and femtosecond pump probe experiments. Based on preliminary results two reaction paths of methylal dissociation are proposed and discussed. (author) 4 fig., 3 refs.

  11. Cryoscopic studies in molten salts: dissociation of some alkali isopolymolybdates and some related molybdenum(VI) compounds in molten potassium dichromate and potassium nitrate

    International Nuclear Information System (INIS)

    Hassanein, M.; Youssef, N.S.

    1982-01-01

    The dissociation of the solutes, viz. M 2 MoO 4 , M 2 MO 3 O 10 , M 2 Mo 4 O 13 , M 2 Mo 5 O 16 (M = Rb or Cs), Na 2 CrO 4 .MoO 3 , K 2 CrO 4 .2MoO 3 , Cr 2 Mo 3 O 12 and V 2 MoO 8 in molten K 2 Cr 2 O 7 and KNO 3 as solvents has been studied employing cryoscopic method. The values of number of foreign ions (ν) show that all the solutes, except V 2 MoO 8 , are either simply dissociated in the melt, or, in some cases after dissociation undergo rearrangement to heteropolyions of the type (CrMo 2 O 10 ) 2- . The solute V 2 MoO 8 , dissolves without any apparent dissociation. An agreement between the experimental and calculated values of activity (a) based on the Temkin and random mixing models and that of Vant Hoff's equation support the proposed simple dissociation scheme for K 2 Cr 2 O 7 -Cs 2 MoO 4 system. (author)

  12. Comparison of reactivity on step and terrace sites of Pd (3 3 2) surface for the dissociative adsorption of hydrogen: A quantum chemical molecular dynamics study

    International Nuclear Information System (INIS)

    Ahmed, Farouq; Nagumo, Ryo; Miura, Ryuji; Ai, Suzuki; Tsuboi, Hideyuki; Hatakeyama, Nozomu; Endou, Akira; Takaba, Hiromitsu; Kubo, Momoji; Miyamoto, Akira

    2011-01-01

    The notion of 'active sites' is fundamental to heterogeneous catalysis. However, the exact nature of the active sites, and hence the mechanism by which they act, are still largely a matter of speculation. In this study, we have presented a systematic quantum chemical molecular dynamics (QCMD) calculations for the interaction of hydrogen on different step and terrace sites of the Pd (3 3 2) surface. Finally the dissociative adsorption of hydrogen on step and terrace as well as the influence of surface hydrogen vacancy for the dissociative adsorption of hydrogen has been investigated through QCMD. This is a state-of-the-art method for calculating the interaction of atoms and molecules with metal surfaces. It is found that fully hydrogen covered (saturated) step sites can dissociate hydrogen moderately and that a monovacancy surface is suitable for significant dissociative adsorption of hydrogen. However in terrace site of the surface we have found that dissociation of hydrogen takes place only on Pd sites where the metal atom is not bound to any pre-adsorbed hydrogen atoms. Furthermore, from the molecular dynamics and electronic structure calculations, we identify a number of consequences for the interpretation and modeling of diffusion experiments demonstrating the coverage and directional dependence of atomic hydrogen diffusion on stepped palladium surface.

  13. Threshold collision-induced dissociation of diatomic molecules: a case study of the energetics and dynamics of O2- collisions with Ar and Xe.

    Science.gov (United States)

    Ahu Akin, F; Ree, Jongbaik; Ervin, Kent M; Kyu Shin, Hyung

    2005-08-08

    The energetics and dynamics of collision-induced dissociation of O2- with Ar and Xe targets are studied experimentally using guided ion-beam tandem mass spectrometry. The cross sections and the collision dynamics are modeled theoretically by classical trajectory calculations. Experimental apparent threshold energies are 2.1 and 1.1 eV in excess of the thermochemical O2- bond dissociation energy for argon and xenon, respectively. Classical trajectory calculations confirm the observed threshold behavior and the dependence of cross sections on the relative kinetic energy. Representative trajectories reveal that the bond dissociation takes place on a short time scale of about 50 fs in strong direct collisions. Collision-induced dissociation is found to be remarkably restricted to the perpendicular approach of ArXe to the molecular axis of O2-, while collinear collisions do not result in dissociation. The higher collisional energy-transfer efficiency of xenon compared with argon is attributed to both mass and polarizability effects.

  14. Threshold collision-induced dissociation of diatomic molecules: A case study of the energetics and dynamics of O2- collisions with Ar and Xe

    International Nuclear Information System (INIS)

    Ahu Akin, F.; Ree, Jongbaik; Ervin, Kent M.; Hyung, Kyu Shin

    2005-01-01

    The energetics and dynamics of collision-induced dissociation of O 2 - with Ar and Xe targets are studied experimentally using guided ion-beam tandem mass spectrometry. The cross sections and the collision dynamics are modeled theoretically by classical trajectory calculations. Experimental apparent threshold energies are 2.1 and 1.1 eV in excess of the thermochemical O 2 - bond dissociation energy for argon and xenon, respectively. Classical trajectory calculations confirm the observed threshold behavior and the dependence of cross sections on the relative kinetic energy. Representative trajectories reveal that the bond dissociation takes place on a short time scale of about 50 fs in strong direct collisions. Collision-induced dissociation is found to be remarkably restricted to the perpendicular approach of Ar/Xe to the molecular axis of O 2 - , while collinear collisions do not result in dissociation. The higher collisional energy-transfer efficiency of xenon compared with argon is attributed to both mass and polarizability effects

  15. Study of noise reduction characteristics of double-wall panels

    Science.gov (United States)

    Navaneethan, R.; Quayle, B.; Stevenson, S.; Graham, M.

    1983-05-01

    The noise reduction characteristics of general aviation type, flat, double-wall structures were investigated. The experimental study was carried out on 20-by-20 inch panels with an exposed area of 18 by 18 inches. A frequency range from 20 to 5000 Hz was covered. The experimental results, in general, follow the expected trends. At low frequencies the double-wall structures are no better than the single-wall structures. However, for depths normally used in the general aviation industry, the double-wall panels are very attractive. The graphite-spoxy skin panels have higher noise reduction at very low frequencies ( 100 Hz) than the Kevlar skin panels. But the aluminum panels have higher noise reduction in the high frequency region, due to their greater mass. Use of fiberglass insulation is not effective in the low frequency region, and at times it is even negative. But the insulation is effective in the high-frequency region. The theoretical model for predicting the transmission loss of these multilayered panels is also discussed.

  16. Biomechanical evaluation of knotless anatomical double-layer double-row rotator cuff repair: a comparative ex vivo study.

    Science.gov (United States)

    Hepp, Pierre; Osterhoff, Georg; Engel, Thomas; Marquass, Bastian; Klink, Thomas; Josten, Christoph

    2009-07-01

    The layered configuration of the rotator cuff tendon is not taken into account in classic rotator cuff tendon repair techniques. The mechanical properties of (1) the classic double-row technique, (2) a double-layer double-row (DLDR) technique in simple suture configuration, and (3) a DLDR technique in mattress suture configuration are significantly different. Controlled laboratory study. Twenty-four sheep shoulders were assigned to 3 repair groups of full-thickness infraspinatus tears: group 1, traditional double-row repair; group 2, DLDR anchor repair with simple suture configuration; and group 3, DLDR knotless repair with mattress suture configuration. After ultrasound evaluation of the repair, each specimen was cyclically loaded with 10 to 100 N for 50 cycles. Each specimen was then loaded to failure at a rate of 1 mm/s. There were no statistically significant differences among the 3 testing groups for the mean footprint area. The cyclic loading test revealed no significant difference among the 3 groups with regard to elongation. For the load-to-failure test, groups 2 and 3 showed no differences in ultimate tensile load when compared with group 1. However, when compared to group 2, group 3 was found to have significantly higher values regarding ultimate load, ultimate elongation, and energy absorbed. The DLDR fixation techniques may provide strength of initial repair comparable with that of commonly used double-row techniques. When compared with the knotless technique with mattress sutures, simple suture configuration of DLDR repair may be too weak. Knotless DLDR rotator cuff repair may (1) restore the footprint by the use of double-row principles and (2) enable restoration of the shape and profile. Double-layer double-row fixation in mattress suture configuration has initial fixation strength comparable with that of the classic double-row fixation and so may potentially improve functional results of rotator cuff repair.

  17. A classical trajectory study of the adatom -surface bond dissociation in the collision reaction between an adsorbed H atom and an N2 molecule

    International Nuclear Information System (INIS)

    Bayhan, U.

    2005-01-01

    The collisionnal dissociation of the Adatom-Surface bond in the diatomic molecule N2(gas)/H(ads) collision taking place on a W(100) bcc-structure surface have been studied by classical trajectory method over the collision energy ranges (0.1-2.0 eV ) and the attractive well depth (0.19-4.0 eV). of the N2 molecule (gas)/H(ads) interactions. When the energy accumulate into the adatom bond, thus leading to a a large dissociation probability

  18. Dissociative and molecular oxygen chemisorption channels on reduced rutile TiO2(110): A high-resolution STM study

    DEFF Research Database (Denmark)

    Lira, Estephania; Hansen, Jonas Ørbæk; Huo, Peipei

    2010-01-01

    High-resolution scanning tunneling microscopy (STM) and temperature-programmed desorption (TPD) were used to study the interaction of O2 with reduced TiO2(110)–(1 × 1) crystals. STM is the technique of choice to unravel the relation between vacancy and non-vacancy assisted O2 dissociation channel...... in the near-surface region of reduced TiO2(110) crystals, the kinetics of the two O2 dissociation channels as well as the kinetics of the diffusion and reaction of Ti interstitials....

  19. Evidence for a Double Dissociation between Spatial-Simultaneous and Spatial-Sequential Working Memory in Visuospatial (Nonverbal) Learning Disabled Children

    Science.gov (United States)

    Mammarella, Irene C.; Cornoldi, Cesare; Pazzaglia, Francesca; Toso, Cristina; Grimoldi, Mario; Vio, Claudio

    2006-01-01

    The paper describes the performance of three children with specific visuospatial working memory (VSWM) impairments (Study 1) and three children with visuospatial (nonverbal) learning disabilities (Study 2) assessed with a battery of working memory (WM) tests and with a number of school achievement tasks. Overall, performance on WM tests provides…

  20. Present status of radiochemical double beta decay study (238U)

    International Nuclear Information System (INIS)

    Madic, C.; Maillard, C.; Chevallier, A.; Chevallier, J.; Escoubes, B.; Schulz, N.; Sens, J.C.

    1989-01-01

    A sensitive experiment has been designed that will be able to measure an assumed half-life of 1.9x10 22 yr. This double beta corresponds to the activity of 27000 238 Pu nuclei formed during a year, in a 200 m deep mine, from 300 kg of 238 U, giving 210 alpha decays per year. Plutonium 238 et 239 will be determined by alpha spectroscopy after extraction chromatography. Experimental studies were undertaken to select the best conditions for running the extraction chromatography cycles

  1. Collision-induced dissociation of diatomic ions

    International Nuclear Information System (INIS)

    Los, J.; Govers, T.R.

    1978-01-01

    An attempt is made to illustrate how mass spectrometric studies of dissociation in diatomic molecular ions can provide information on the dynamics of these collisions and on the predissociative states involved. Restriction is made to primary beam energies of the order of at least keV. The review covers the dynamics of dissociation, experimental techniques, direct dissociation in heavy-particle collisions, and translational spectroscopy. 120 references

  2. Experimentally-induced dissociation impairs visual memory.

    Science.gov (United States)

    Brewin, Chris R; Mersaditabari, Niloufar

    2013-12-01

    Dissociation is a phenomenon common in a number of psychological disorders and has been frequently suggested to impair memory for traumatic events. In this study we explored the effects of dissociation on visual memory. A dissociative state was induced experimentally using a mirror-gazing task and its short-term effects on memory performance were investigated. Sixty healthy individuals took part in the experiment. Induced dissociation impaired visual memory performance relative to a control condition; however, the degree of dissociation was not associated with lower memory scores in the experimental group. The results have theoretical and practical implications for individuals who experience frequent dissociative states such as patients with posttraumatic stress disorder (PTSD). Copyright © 2013 Elsevier Inc. All rights reserved.

  3. A Cross-Lagged Panel Study of Dissociation and Posttraumatic Stress in a Treatment-Seeking Sample of Survivors of Childhood Sexual Abuse

    DEFF Research Database (Denmark)

    Murphy, Siobhan; Elklit, Ask; Murphy, Jamie

    2017-01-01

    Objective: The current prospective study assessed the temporal relations between dissociation and posttraumatic stress (PTS) in a sample of treatment-seeking female survivors of childhood sexual abuse. PTS refers to symptoms associated with posttraumatic stress disorder (PTSD) in the absence...... clinical implications that may affect their treatment and trauma recovery....

  4. SFG study of methanol dissociative adsorption at Pt(1 0 0), Pt(1 1 0) and Pt(1 1 1) electrodes surfaces

    Science.gov (United States)

    Vidal, F.; Busson, B.; Six, C.; Pluchery, O.; Tadjeddine, A.

    2002-04-01

    The Pt( hkl)/methanol in acidic solution interface which constitutes a model of the anodic part of a fuel cell is studied by infrared-visible sum frequency generation vibrational spectroscopy. Methanol dissociative adsorption leads to CO poisoning of the Pt electrode surfaces. The structure of the CO/Pt( hkl) interface depends strongly on the orientation of the surface electrode.

  5. Dissociations of the Fluocinolone Acetonide Implant: The Multicenter Uveitis Steroid Treatment (MUST) Trial and Follow-up Study.

    Science.gov (United States)

    Holbrook, Janet T; Sugar, Elizabeth A; Burke, Alyce E; Vitale, Albert T; Thorne, Jennifer E; Davis, Janet L; Jabs, Douglas A

    2016-04-01

    To describe fluocinolone acetonide implant dissociations in the Multicenter Uveitis Steroid Treatment (MUST) Trial. Randomized clinical trial with extended follow-up. Review of data collected on the first implant in the eye(s) of participants. Dissociation was defined as the drug pellet no longer being affixed to the strut and categorized as spontaneous or surgically related. A total of 250 eyes (146 patients) had at least 1 implant placed. Median follow-up time after implant placement was 6 years (range 0.5-9.2 years). Thirty-four dissociations were reported in 30 participants. There were 22 spontaneous events in 22 participants; 6-year cumulative risk of a spontaneous dissociation was 4.8% (95% confidence interval [CI]: 2.4%-9.1%). The earliest event occurred 4.8 years after placement. Nine of 22 eyes with data had a decline in visual acuity ≥5 letters temporally related to the dissociation. Thirty-nine implant removal surgeries were performed, 33 with replacement. Twelve dissociations were noted during implant removal surgeries in 10 participants (26%, 95% CI 15%-48%); 5 of these eyes had a decline in visual acuity ≥5 letters after surgery. The time from implant placement to removal surgery was longer for the surgeries at which dissociated implants were identified than for those without one (5.7 vs 3.7 years, P uveitis or its treatment. There is an increasing risk of dissociation of Retisert implants during follow-up; the risk is greater with removal/exchange surgeries, but the risk of both spontaneous and surgically related events increases with longevity of the implants. In 22% of affected eyes visual acuity declined by 15 letters. In the context of eyes with moderate to severe uveitis for years, this rate is not unexpected. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Dissociation and Memory Fragmentation in Posttraumatic Stress Disorder: An Evaluation of the Dissociative Encoding Hypothesis

    Science.gov (United States)

    Bedard-Gilligan, Michele; Zoellner, Lori A.

    2012-01-01

    Several prominent theories of posttraumatic stress disorder (PTSD) posit that peritraumatic dissociation results in insufficient encoding of the trauma memory and that persistent dissociation prevents memory elaboration, resulting in memory fragmentation and PTSD. In this review, we summarize the empirical literature on peritraumatic and trait dissociation and trauma narrative fragmentation as measured by meta-memory and rater/objective coding. Across 16 studies to date, the association between dissociation and fragmentation was most prominent when examining peritraumatic dissociation and patient's own ratings of memory fragmentation. This relationship did not hold when examining trait dissociation or rater-coded or computer-generated measures of fragmentation. Thus, initial evidence points more toward a strong self-reported association between constructs that is not supported on more objective fragmentation coding. Measurement overlap, construct ambiguity, and exclusion of potential confounds may underlie lack of a strong association between dissociation and objective-rated fragmentation. PMID:22348400

  7. Double dissociation of the anterior and posterior dorsomedial caudate-putamen in the acquisition and expression of associative learning with the nicotine stimulus.

    Science.gov (United States)

    Charntikov, Sergios; Pittenger, Steven T; Swalve, Natashia; Li, Ming; Bevins, Rick A

    2017-07-15

    Tobacco use is the leading cause of preventable deaths worldwide. This habit is not only debilitating to individual users but also to those around them (second-hand smoking). Nicotine is the main addictive component of tobacco products and is a moderate stimulant and a mild reinforcer. Importantly, besides its unconditional effects, nicotine also has conditioned stimulus effects that may contribute to the tenacity of the smoking habit. Because the neurobiological substrates underlying these processes are virtually unexplored, the present study investigated the functional involvement of the dorsomedial caudate putamen (dmCPu) in learning processes with nicotine as an interoceptive stimulus. Rats were trained using the discriminated goal-tracking task where nicotine injections (0.4 mg/kg; SC), on some days, were paired with intermittent (36 per session) sucrose deliveries; sucrose was not available on interspersed saline days. Pre-training excitotoxic or post-training transient lesions of anterior or posterior dmCPu were used to elucidate the role of these areas in acquisition or expression of associative learning with nicotine stimulus. Pre-training lesion of p-dmCPu inhibited acquisition while post-training lesions of p-dmCPu attenuated the expression of associative learning with the nicotine stimulus. On the other hand, post-training lesions of a-dmCPu evoked nicotine-like responding following saline treatment indicating the role of this area in disinhibition of learned motor behaviors. These results, for the first time, show functionally distinct involvement of a- and p-dmCPu in various stages of associative learning using nicotine stimulus and provide an initial account of neural plasticity underlying these learning processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Control over the Strength of Connections Between Modules: A Double Dissociation Between Stimulus Format and Task Revealed by Granger Causality Mapping in fMRI

    Directory of Open Access Journals (Sweden)

    Britt eAnderson

    2015-03-01

    Full Text Available Drawing on theoretical and computational work with the localist Dual Route reading model and results from behavioral studies, Besner, Moroz, and O'Malley (2011 proposed that the ability to perform tasks that require overriding stimulus-specific defaults (e.g., semantics when naming Arabic numerals, and phonology when evaluating the parity of number words necessitate the ability to modulate the strength of connections between cognitive modules for lexical representation, semantics, and phonology on a task- and stimulus-specific basis. We used fMRI to evaluate this account by assessing changes in functional connectivity while participants performed tasks that did and did not require such stimulus-task default overrides. The occipital region showing the greatest modulation of BOLD signal strength for the two stimulus types was used as the seed region for Granger Causality Mapping (GCM. Our GCM analysis revealed a region of rostromedial frontal cortex with a crossover interaction. When participants performed tasks that required overriding stimulus type defaults (i.e., parity judgments of number words and naming Arabic numerals functional connectivity between the occipital region and rostromedial frontal cortex was present. Statistically significant functional connectivity was absent when the tasks were the default for the stimulus type (i.e., parity judgments of Arabic numerals and reading number words. This frontal region (BA 10 has previously been shown to be involved in goal-directed behaviour and maintenance of a specific task-set. We conclude that overriding stimulus-task defaults requires a modulation of connection strengths between cognitive modules and that the override mechanism predicted from cognitive theory is instantiated by frontal modulation of neural activity of brain regions specialized for sensory processing.

  9. Neural Dissociation of Number from Letter Recognition and Its Relationship to Parietal Numerical Processing

    Science.gov (United States)

    Park, Joonkoo; Hebrank, Andrew; Polk, Thad A.; Park, Denise C.

    2012-01-01

    The visual recognition of letters dissociates from the recognition of numbers at both the behavioral and neural level. In this article, using fMRI, we investigate whether the visual recognition of numbers dissociates from letters, thereby establishing a double dissociation. In Experiment 1, participants viewed strings of consonants and Arabic…

  10. Reconsidering the autohypnotic model of the dissociative disorders.

    Science.gov (United States)

    Dell, Paul F

    2018-03-22

    The dissociative disorders field and the hypnosis field currently reject the autohypnotic model of the dissociative disorders, largely because many correlational studies have shown hypnotizability and dissociation to be minimally related (r = .12). Curiously, it is also widely accepted that dissociative patients are highly hypnotizable. If dissociative patients are highly hypnotizable because only highly hypnotizable individuals can develop a dissociative disorder - as the author proposes - then the methodology of correlational studies of hypnotizability and dissociation in random clinical and community samples would necessarily be constitutively unable to detect, and statistically unable to reflect, that fact. That is, the autohypnotic, dissociative distancing of that small subset of highly hypnotizable individuals who repeatedly encountered intolerable circumstances is statistically lost among the data of (1) the highly hypnotizable subjects who do not dissociate and (2) subjects (of all levels of hypnotizability) who manifest other kinds of dissociation. The author proposes that, when highly hypnotizable individuals repeatedly engage in autohypnotic distancing from intolerable circumstances, they develop an overlearned, highly-motivated, automatized pattern of dissociative self-protection (i.e., a dissociative disorder). The author urges that theorists of hypnosis and the dissociative disorders explicitly include in their theories (a) the trait of high hypnotizability, (b) the phenomena of autohypnosis, and (c) the manifestations of systematized, autohypnotic pathology. Said differently, the author is suggesting that autohypnosis and autohypnotic pathology are unacknowledged nodes in the nomothetic networks of both hypnosis and dissociation.

  11. Theoretical study (ab initio and DFT methods on acidic dissociation constant of xylenol orange in aqueous solution

    Directory of Open Access Journals (Sweden)

    F. Kiani

    2017-07-01

    Full Text Available Analytical measurement of materials requires exact knowledge of their acid dissociation constant (pKa values. In recent years, quantum mechanical calculations have been extensively used to study of acidities in the aqueous solutions and the results were compared with the experimental values. In this study, a theoretical study was carried out on xylenol orange (in water solution by ab initio method. We calculated the pKa values of xylenol orange in water, using high-level ab initio (PM3, DFT (HF, B3LYP/6-31+G(d and SCRF methods. The experimental determination of these values (pKa,s is a challenge because xylenol orange has a low solubility in water. We considered several ionization reactions and equilibriums in water that constitute the indispensable theoretical basis to calculate the pKa values of xylenol orange. The results show that the calculated pKa values have a comparable agreement with the experimentally determined pKa values. Therefore, this method can be used to predict such properties for indicators, drugs and other important molecules.

  12. An analytical study of double bend achromat lattice

    Energy Technology Data Exchange (ETDEWEB)

    Fakhri, Ali Akbar, E-mail: fakhri@rrcat.gov.in; Kant, Pradeep; Singh, Gurnam; Ghodke, A. D. [Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)

    2015-03-15

    In a double bend achromat, Chasman-Green (CG) lattice represents the basic structure for low emittance synchrotron radiation sources. In the basic structure of CG lattice single focussing quadrupole (QF) magnet is used to form an achromat. In this paper, this CG lattice is discussed and an analytical relation is presented, showing the limitation of basic CG lattice to provide the theoretical minimum beam emittance in achromatic condition. To satisfy theoretical minimum beam emittance parameters, achromat having two, three, and four quadrupole structures is presented. In this structure, different arrangements of QF and defocusing quadruple (QD) are used. An analytical approach assuming quadrupoles as thin lenses has been followed for studying these structures. A study of Indus-2 lattice in which QF-QD-QF configuration in the achromat part has been adopted is also presented.

  13. An analytical study of double bend achromat lattice.

    Science.gov (United States)

    Fakhri, Ali Akbar; Kant, Pradeep; Singh, Gurnam; Ghodke, A D

    2015-03-01

    In a double bend achromat, Chasman-Green (CG) lattice represents the basic structure for low emittance synchrotron radiation sources. In the basic structure of CG lattice single focussing quadrupole (QF) magnet is used to form an achromat. In this paper, this CG lattice is discussed and an analytical relation is presented, showing the limitation of basic CG lattice to provide the theoretical minimum beam emittance in achromatic condition. To satisfy theoretical minimum beam emittance parameters, achromat having two, three, and four quadrupole structures is presented. In this structure, different arrangements of QF and defocusing quadruple (QD) are used. An analytical approach assuming quadrupoles as thin lenses has been followed for studying these structures. A study of Indus-2 lattice in which QF-QD-QF configuration in the achromat part has been adopted is also presented.

  14. An analytical study of double bend achromat lattice

    International Nuclear Information System (INIS)

    Fakhri, Ali Akbar; Kant, Pradeep; Singh, Gurnam; Ghodke, A. D.

    2015-01-01

    In a double bend achromat, Chasman-Green (CG) lattice represents the basic structure for low emittance synchrotron radiation sources. In the basic structure of CG lattice single focussing quadrupole (QF) magnet is used to form an achromat. In this paper, this CG lattice is discussed and an analytical relation is presented, showing the limitation of basic CG lattice to provide the theoretical minimum beam emittance in achromatic condition. To satisfy theoretical minimum beam emittance parameters, achromat having two, three, and four quadrupole structures is presented. In this structure, different arrangements of QF and defocusing quadruple (QD) are used. An analytical approach assuming quadrupoles as thin lenses has been followed for studying these structures. A study of Indus-2 lattice in which QF-QD-QF configuration in the achromat part has been adopted is also presented

  15. Hydrogen dissociation and incorporation on Mg{sub 17}Al{sub 12}(100) surface: A density functional theory study

    Energy Technology Data Exchange (ETDEWEB)

    Ning, Hua [Guangxi Key Laboratory for Relativistic Astrophysics, Guangxi Colleges and Universities Key Laboratory of Novel Energy Materials and Related Technology, College of Physics Science and Technology, Guangxi University, Nanning 530004 (China); Guangxi Collaborative Innovation Center of Structure and Property for New Energy and Materials, School of Material Science and Engineering, Guilin University of Electronic Technology, Guilin 541004 (China); Zhou, Zhiyan; Zhang, Ziyan [Guangxi Key Laboratory for Relativistic Astrophysics, Guangxi Colleges and Universities Key Laboratory of Novel Energy Materials and Related Technology, College of Physics Science and Technology, Guangxi University, Nanning 530004 (China); Zhou, Wenzheng; Li, Guangxu [Guangxi Key Laboratory for Relativistic Astrophysics, Guangxi Colleges and Universities Key Laboratory of Novel Energy Materials and Related Technology, College of Physics Science and Technology, Guangxi University, Nanning 530004 (China); Guangxi Collaborative Innovation Center of Structure and Property for New Energy and Materials, School of Material Science and Engineering, Guilin University of Electronic Technology, Guilin 541004 (China); Guo, Jin, E-mail: guojin@gxu.edu.cn [Guangxi Key Laboratory for Relativistic Astrophysics, Guangxi Colleges and Universities Key Laboratory of Novel Energy Materials and Related Technology, College of Physics Science and Technology, Guangxi University, Nanning 530004 (China); Guangxi Collaborative Innovation Center of Structure and Property for New Energy and Materials, School of Material Science and Engineering, Guilin University of Electronic Technology, Guilin 541004 (China)

    2017-02-28

    Highlights: • Hydrogen adsorption, dissociation, and penetration on (in) Mg{sub 17}Al{sub 12} (100) surface are studied. • Hydrogen molecules are dissociated on the surface with barrier of 0.63 eV. • The maximum barrier energy for atomic hydrogen penetration into the subsurface is ∼0.7 eV. • The hybridization between the s orbital of H and the s orbitals of Mg is major. - Abstract: Hydrogen adsorption, dissociation, and penetration on (in) Mg{sub 17}Al{sub 12} (100) surface are studied extensively by DFT total-energy calculations. The adsorption geometries, dissociation barriers, various diffusion pathways, penetrative processes, and electronic structures were investigated. Results show that the atomic and molecular hydrogen forms prefer to be adsorbed on the Mg3-Mg3 bridge sites (C sites). Hydrogen molecules are dissociated on the surface with the minimum barrier energy of 0.63 eV. There are two stages in the process of hydrogen incorporation, which are hydrogen diffusion on the surface and the penetration from the surface into the subsurface. Two possible pathways of atomic hydrogen penetration from surface into subsurface are found. The calculations of electronic structures show that the hybridization between the s orbital of H and the s orbitals of Mg is major. The Mg-Mg bond on the outmost surface is shortened from 4.48 Å to 3.30 Å after the hydrogen adsorption on C sites, showing the strong interaction between Mg and H atoms.

  16. The Progressive Approach to EMDR Group Therapy for Complex Trauma and Dissociation: A Case-Control Study

    Directory of Open Access Journals (Sweden)

    Ana I. Gonzalez-Vazquez

    2018-02-01

    Full Text Available Eye Movement Desensitization and Reprocessing is a psychotherapeutic approach with recognized efficiency in treating post-traumatic stress disorder (PTSD, which is being used and studied in other psychiatric diagnoses partially based on adverse and traumatic life experiences. Nevertheless, there is not enough empirical evidence at the moment to support its usefulness in a diagnosis other than PTSD. It is commonly accepted that the use of EMDR in severely traumatized patients requires an extended stabilization phase. Some authors have proposed integrating both the theory of structural dissociation of the personality and the adaptive information processing model guiding EMDR therapy. One of these proposals is the Progressive Approach. Some of these EMDR procedures will be evaluated in a group therapy format, integrating them along with emotional regulation, dissociation, and trauma-oriented psychoeducational interventions. Patients presenting a history of severe traumatization, mostly early severe and interpersonal trauma, combined with additional significant traumatizing events in adulthood were included. In order to discriminate the specific effect of EMDR procedures, two types of groups were compared: TAU (treatment as usual: psychoeducational intervention only vs. TAU+EMDR (the same psychoeducational intervention plus EMDR specific procedures. In pre-post comparison, more variables presented positive changes in the group including EMDR procedures. In the TAU+EMDR group, 4 of the 5 measured variables presented significant and positive changes: general health (GHQ, general satisfaction (Schwartz, subjective well-being, and therapy session usefulness assessment. On the contrary, only 2 of the 5 variables in the TAU group showed statistically significant changes: general health (GHQ, and general satisfaction (Schwartz. Regarding post-test inter-group comparison, improvement in subjective well-being was related to belonging to the group that

  17. Comparative study of the conformational lock, dissociative thermal inactivation and stability of euphorbia latex and lentil seedling amine oxidases.

    Science.gov (United States)

    Amani, M; Moosavi-Movahedi, A A; Floris, G; Longu, S; Mura, A; Moosavi-Nejad, S Z; Saboury, A A; Ahmad, F

    2005-04-01

    The thermal stability of copper/quinone containing amine oxidases from Euphorbia characias latex (ELAO) and lentil seedlings (LSAO) was measured in 100 mM potassium phosphate buffer (pH 7.0) following changes in absorbance at 292 nm. ELAO was shown to be about 10 degrees C more stable than LSAO. The dissociative thermal inactivation of ELAO was studied using putrescine as substrate at different temperatures in the range 47-70 degrees C, and a "conformational lock" was developed using the theory pertaining to oligomeric enzyme. Moreover ELAO was shown to be more stable towards denaturants than LSAO, as confirmed by dodecyl trimethylammonium bromide denaturation curves. A comparison of the numbers of contact sites in inter-subunits of ELAO relative to LSAO led us to conclude that the higher stability of ELAO to temperature and towards denaturants was due to the presence of larger number of contact sites in the conformational lock of the enzyme. This study also gives a putative common mechanism for thermal inactivation of amine oxidases and explains the importance of C-terminal conserved amino acids residues in this class of enzymes.

  18. Dissociations between developmental dyslexias and attention deficits

    Science.gov (United States)

    Lukov, Limor; Friedmann, Naama; Shalev, Lilach; Khentov-Kraus, Lilach; Shalev, Nir; Lorber, Rakefet; Guggenheim, Revital

    2014-01-01

    We examine whether attention deficits underlie developmental dyslexia, or certain types of dyslexia, by presenting double dissociations between the two. We took into account the existence of distinct types of dyslexia and of attention deficits, and focused on dyslexias that may be thought to have an attentional basis: letter position dyslexia (LPD), in which letters migrate within words, attentional dyslexia (AD), in which letters migrate between words, neglect dyslexia, in which letters on one side of the word are omitted or substituted, and surface dyslexia, in which words are read via the sublexical route. We tested 110 children and adults with developmental dyslexia and/or attention deficits, using extensive batteries of reading and attention. For each participant, the existence of dyslexia and the dyslexia type were tested using reading tests that included stimuli sensitive to the various dyslexia types. Attention deficit and its type was established through attention tasks assessing sustained, selective, orienting, and executive attention functioning. Using this procedure, we identified 55 participants who showed a double dissociation between reading and attention: 28 had dyslexia with normal attention and 27 had attention deficits with normal reading. Importantly, each dyslexia with suspected attentional basis dissociated from attention: we found 21 individuals with LPD, 13 AD, 2 neglect dyslexia, and 12 surface dyslexia without attention deficits. Other dyslexia types (vowel dyslexia, phonological dyslexia, visual dyslexia) also dissociated from attention deficits. Examination of 55 additional individuals with both a specific dyslexia and a certain attention deficit found no attention function that was consistently linked with any dyslexia type. Specifically, LPD and AD dissociated from selective attention, neglect dyslexia dissociated from orienting, and surface dyslexia dissociated from sustained and executive attention. These results indicate that

  19. Study of a double bubbler for material balance in liquids

    Energy Technology Data Exchange (ETDEWEB)

    Hugues Lambert

    2013-09-01

    The objective of this project was to determine the potential of a double bubbler to measure density and fluid level of the molten salt contained in an electrorefiner. Such in-situ real-time measurements can provide key information for material balances in the pyroprocessing of the nuclear spent fuel. This theoretical study showed this technique has a lot of promise. Four different experiments were designed and performed. The first three experiments studied the influence of a variety of factors such as depth difference between the two tubes, gas flow rate, the radius of the tubes and determining the best operating conditions. The last experiment purpose was to determine the precision and accuracy of the apparatus during specific conditions. The elected operating conditions for the characterization of the system were a difference of depth of 25 cm and a flow rate of 55 ml/min in each tube. The measured densities were between 1,000 g/l and 1,400g/l and the level between 34cm and 40 cm. The depth difference between the tubes is critical, the larger, the better. The experiments showed that the flow rate should be the same in each tube. The concordances with theoretical predictions were very good. The density precision was very satisfying (spread<0.1%) and the accuracy was about 1%. For the level determination, the precision was also very satisfying (spread<0.1%), but the accuracy was about 3%. However, those two biases could be corrected with calibration curves. In addition to the aqueous systems studied in the present work, future work will focus on examining the behavior of the double bubbler instrumentation in molten salt systems. The two main challenges which were identified in this work are the effect of the temperature and the variation of the superficial tension.

  20. Monte Carlo study of double exchange interaction in manganese oxide

    Energy Technology Data Exchange (ETDEWEB)

    Naa, Christian Fredy, E-mail: chris@cphys.fi.itb.ac.id [Physics Department, Faculty of Mathematics and Natural Science, Institut Teknologi Bandung, Jalan Ganesha 10 Bandung (Indonesia); Unité de Dynamique et Structure des Matérioux Moléculaires, Université Littoral Côte d’Opale, Maison de la Reserche Blaise Pascal 50, rue Ferdinand Buisson, Calais, France email (France); Suprijadi,, E-mail: supri@fi.itb.ac.id; Viridi, Sparisoma, E-mail: dudung@fi.itb.ac.id; Djamal, Mitra, E-mail: mitra@fi.itb.ac.id [Physics Department, Faculty of Mathematics and Natural Science, Institut Teknologi Bandung, Jalan Ganesha 10 Bandung (Indonesia); Fasquelle, Didier, E-mail: didier.fasquelle@univ-littoral.fr [Unité de Dynamique et Structure des Matérioux Moléculaires, Université Littoral Côte d’Opale, Maison de la Reserche Blaise Pascal 50, rue Ferdinand Buisson, Calais, France email (France)

    2015-09-30

    In this paper we study the magnetoresistance properties attributed by double exchange (DE) interaction in manganese oxide by Monte Carlo simulation. We construct a model based on mixed-valence Mn{sup 3+} and Mn{sup 4+} on the general system of Re{sub 2/3}Ae{sub 1/3}MnO{sub 3} in two dimensional system. The conduction mechanism is based on probability of e{sub g} electrons hopping from Mn{sup 3+} to Mn{sup 4+}. The resistivity dependence on temperature and the external magnetic field are presented and the validity with related experimental results are discussed. We use the resistivity power law to fit our data on metallic region and basic activated behavior on insulator region. On metallic region, we found our result agree well with the quantum theory of DE interaction. From general arguments, we found our simulation agree qualitatively with experimental results.

  1. Double rotation NMR studies of zeolites and aluminophosphate molecular sieves

    Energy Technology Data Exchange (ETDEWEB)

    Jelinek, Raz [Univ. of California, Berkeley, CA (United States)

    1993-07-01

    Goal is to study the organization and structures of guest atoms and molecules and their reactions on internal surfaces within pores of zeolites and aluminophosphate molecular sieves. 27Al and 23Na double rotation NMR (DOR) is used since it removes the anisotropic broadening in NMR spectra of quadrupolar nuclei, thus increasing resolution. This work concentrates on probing aluminum framework atoms in aluminophosphate molecular sieves and sodium extra framework cations in porous aluminosilicates. In aluminophosphates, ordering and electronic environments of the framework 27Al nuclei are modified upon adsorption of water molecules within the channels; a relation is sought between the sieve channel topology and the organization of adsorbed water, as well as the interaction between the Al nuclei and the water molecules. Extra framework Na+ cations are directly involved in adsorption processes and reactions in zeolite cavities.

  2. Some double resonance and multiple quantum NMR studies in solids

    Energy Technology Data Exchange (ETDEWEB)

    Wemmer, D.E.

    1978-08-01

    The first section of this work presents the theory and experimental applications to analysis of molecular motion of chemical shielding lineshapes obtained with high resolution double resonance NMR techniques. Analysis of /sup 13/C powder lineshapes in hexamethylbenzene (HMB) and decamethylferrocene (DMFe) show that these molecules reorient in a jumping manner about the symmetry axis. Analysis of proton chemical shielding lineshapes of residual protons in heavy ice (D/sub 2/O) show that protons are exchanged among the tetrahedral positions of neighboring oxygen atoms, consistent with motion expected from defect migration. The second section describes the application of Fourier Transform Double Quantum NMR to measurement of chemical shielding of deuterium in powder samples. Studies of partially deuterated benzene and ferrocene give equal shielding anisotropies, ..delta..sigma = -6.5 ppM. Theoretical predictions and experimental measurements of dipolar couplings between deuterons using FTDQ NMR are presented. Crystals of BaClO/sub 3/.D/sub 2/O, ..cap alpha..,..beta.. d-2 HMB and ..cap alpha..,..beta..,..gamma.. d-3 HMB were studied, as were powders of d-2 HMB and anisic acid. The third section discusses general multiple quantum spectroscopy in dipolar coupled spin systems. Theoretical description is made for creation and detection of coherences between states without quantum number selection rules ..delta..m = +-1. Descriptions of techniques for partial selectivity of order in preparation and detection of multiple quantum coherences are made. The effects on selectivity and resolution of echo pulses during multiple quantum experiments are discussed. Experimental observation of coherences up to order 6 have been made in a sample of benzene dissolved in a liquid crystal. Experimental verifications of order selection and echo generation have been made.

  3. Some double resonance and multiple quantum NMR studies in solids

    International Nuclear Information System (INIS)

    Wemmer, D.E.

    1978-08-01

    The first section of this work presents the theory and experimental applications to analysis of molecular motion of chemical shielding lineshapes obtained with high resolution double resonance NMR techniques. Analysis of 13 C powder lineshapes in hexamethylbenzene (HMB) and decamethylferrocene (DMFe) show that these molecules reorient in a jumping manner about the symmetry axis. Analysis of proton chemical shielding lineshapes of residual protons in heavy ice (D 2 O) show that protons are exchanged among the tetrahedral positions of neighboring oxygen atoms, consistent with motion expected from defect migration. The second section describes the application of Fourier Transform Double Quantum NMR to measurement of chemical shielding of deuterium in powder samples. Studies of partially deuterated benzene and ferrocene give equal shielding anisotropies, Δsigma = -6.5 ppM. Theoretical predictions and experimental measurements of dipolar couplings between deuterons using FTDQ NMR are presented. Crystals of BaClO 3 .D 2 O, α,β d-2 HMB and α,β,γ d-3 HMB were studied, as were powders of d-2 HMB and anisic acid. The third section discusses general multiple quantum spectroscopy in dipolar coupled spin systems. Theoretical description is made for creation and detection of coherences between states without quantum number selection rules Δm = +-1. Descriptions of techniques for partial selectivity of order in preparation and detection of multiple quantum coherences are made. The effects on selectivity and resolution of echo pulses during multiple quantum experiments are discussed. Experimental observation of coherences up to order 6 have been made in a sample of benzene dissolved in a liquid crystal. Experimental verifications of order selection and echo generation have been made

  4. Study of double scattering effect in antiproton--deuteron annihilation

    International Nuclear Information System (INIS)

    Zemany, P.D.

    1975-01-01

    The double scattering process in the deuteron is investigated for the reaction anti pd → p/sub s/ + mesons. About 30 percent of the apparent anti pn annihilations are involved in double scattering. A model which describes the properties of protons emerging from apparent anti pn annihilations is presented

  5. Dissociating maternal responses to sad and happy facial expressions of their own child: An fMRI study.

    Science.gov (United States)

    Kluczniok, Dorothea; Hindi Attar, Catherine; Stein, Jenny; Poppinga, Sina; Fydrich, Thomas; Jaite, Charlotte; Kappel, Viola; Brunner, Romuald; Herpertz, Sabine C; Boedeker, Katja; Bermpohl, Felix

    2017-01-01

    Maternal sensitive behavior depends on recognizing one's own child's affective states. The present study investigated distinct and overlapping neural responses of mothers to sad and happy facial expressions of their own child (in comparison to facial expressions of an unfamiliar child). We used functional MRI to measure dissociable and overlapping activation patterns in 27 healthy mothers in response to happy, neutral and sad facial expressions of their own school-aged child and a gender- and age-matched unfamiliar child. To investigate differential activation to sad compared to happy faces of one's own child, we used interaction contrasts. During the scan, mothers had to indicate the affect of the presented face. After scanning, they were asked to rate the perceived emotional arousal and valence levels for each face using a 7-point Likert-scale (adapted SAM version). While viewing their own child's sad faces, mothers showed activation in the amygdala and anterior cingulate cortex whereas happy facial expressions of the own child elicited activation in the hippocampus. Conjoint activation in response to one's own child happy and sad expressions was found in the insula and the superior temporal gyrus. Maternal brain activations differed depending on the child's affective state. Sad faces of the own child activated areas commonly associated with a threat detection network, whereas happy faces activated reward related brain areas. Overlapping activation was found in empathy related networks. These distinct neural activation patterns might facilitate sensitive maternal behavior.

  6. Dissociation of explicit and implicit long-term memory consolidation in semantic dementia: a case study.

    Science.gov (United States)

    Tu, S; Mioshi, E; Savage, S; Hodges, J R; Hornberger, M

    2013-08-01

    We report a case study of a semantic dementia patient, whose episodic memory consolidation was tested over a 2-month period. The results reveal that despite early retention of information, the patient lost all explicit information of the newly learnt material after 2 weeks. By contrast, he retained implicit word information even after a 4-week delay. These findings highlight the critical time window of 2-4 weeks in which newly learnt information should be re-encoded in rehabilitations studies. The results also indicate that learnt information can be still accessed with implicit retrieval strategies when explicit retrieval fails.

  7. Сombination of Knowledge of Mathematics and Chemistry in the Study of the Theme “Water Dissociation. Power of Hydrogen” in the Inorganic Chemistry Course

    OpenAIRE

    Melnyk, D. O.

    2014-01-01

    The aim of this work was to show effective and convenient way of studying the theme “Water Dissociation. Power of Hydrogen” and facilitate the new material perception by students of pharmaceutical faculty using knowledge of mathematics and chemistry. The correct calculation of pH and ions concentration in solution is necessary for complete perception of the theoretical bases of many disciplines. Using such approach in the study of this theme increases the student's ability to solve the proble...

  8. Inflight dissociation of zircon in air plasma

    Energy Technology Data Exchange (ETDEWEB)

    Yugeswaran, S; Selvarajan, V [Bharathiar University, Coimbatore 641046 (India); Ananthapadmanabhan, P V; Thiyagarajan, T K [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai - 400 085 (India); Nair, Janardhanan [Ion Arc Technologies Pvt Ltd, Coimbatore (India)

    2010-02-01

    Thermal dissociation of zircon can be conveniently carried out in a plasma reactor, which is characterized by high temperature, high energy density and high quench rate. Zirconia is recovered from this partially dissociated zircon by alkali leaching. Dissociation of zircon has been conventionally carried out in argon gas, which is expensive. The present paper reports experimental results on thermal dissociation of zircon in air plasma medium. Process simulation for 'inflight' dissociation of zircon in air plasma medium is also presented. The experimental system consists of a central hollow graphite electrode, which acts as the cathode and a graphite anode. The material to be processed is fed centrally through the cathode. The unique feature of the system is that it uses air as the working gas to generate the thermal plasma. The system has been used to study in-flight dissociation of zircon in the thermal plasma jet. Dissociation was carried out over 10-25 kW power range. Results of the study indicate that complete dissociation of zircon to ZrO{sub 2} and silica could be accomplished at 25 kW in air plasma.

  9. Inflight dissociation of zircon in air plasma

    International Nuclear Information System (INIS)

    Yugeswaran, S; Selvarajan, V; Ananthapadmanabhan, P V; Thiyagarajan, T K; Nair, Janardhanan

    2010-01-01

    Thermal dissociation of zircon can be conveniently carried out in a plasma reactor, which is characterized by high temperature, high energy density and high quench rate. Zirconia is recovered from this partially dissociated zircon by alkali leaching. Dissociation of zircon has been conventionally carried out in argon gas, which is expensive. The present paper reports experimental results on thermal dissociation of zircon in air plasma medium. Process simulation for 'inflight' dissociation of zircon in air plasma medium is also presented. The experimental system consists of a central hollow graphite electrode, which acts as the cathode and a graphite anode. The material to be processed is fed centrally through the cathode. The unique feature of the system is that it uses air as the working gas to generate the thermal plasma. The system has been used to study in-flight dissociation of zircon in the thermal plasma jet. Dissociation was carried out over 10-25 kW power range. Results of the study indicate that complete dissociation of zircon to ZrO 2 and silica could be accomplished at 25 kW in air plasma.

  10. Energy localization and molecular dissociation

    International Nuclear Information System (INIS)

    Takeno, S.; Tsironis, G.P.

    2005-01-01

    We study analytically as well as numerically the role that large-amplitude vibrations play during the process of molecular dissociation. Our model consists of a linear three-atom molecule composed of identical atoms interacting with their nearest neighbors by Morse potentials. We find a close relation between energy localization and bond breaking and evaluate numerically the corresponding reaction paths

  11. Dissociation in mediation

    Directory of Open Access Journals (Sweden)

    Daniela Muraru

    2008-01-01

    Full Text Available This paper approaches several texts that are part of the so-called discourse of mediation, adopting a pragma-dialectical perspective of the theory of dissociation. It is an attempt to identify the uses of dissociative patterns, with special emphasis on the indicators of dissociation. The paper investigates the various uses of the concept of dissociation as a discursive technique in the argumentation on the different aspects that are involved in international conflict, such as the discussion of the notion of peace. The purpose is to identify the role of dissociation, as a device strategically used by the mediator to help the parties minimize the disagreement space, and come to a conflict resolution.

  12. Transport studies in p-type double quantum well samples

    International Nuclear Information System (INIS)

    Hyndman, R.J.

    2000-01-01

    The motivation for the study of double quantum well samples is that the extra spatial degree of freedom can modify the ground state energies of the system, leading to new and interesting many body effects. Electron bi-layers have been widely studied but the work presented here is the first systematic study of transport properties of a p-type, double quantum well system. The samples, grown on the 311 plane, consisted of two 100A GaAs wells separated by a 30A AlAs barrier. The thin barrier in our structures, gives rise to very strong inter-layer Coulombic interactions but in contrast to electron double quantum well samples, tunnelling between the two wells is very weak. This is due to the large effective mass of holes compared with electrons. It is possible to accurately control the total density of a sample and the relative occupancy of each well using front and back gates. A systematic study of the magnetoresistance properties of the p-type bi-layers, was carried out at low temperatures and in high magnetic fields, for samples covering a range of densities. Considerable care was required to obtain reliable results as the samples were extremely susceptible to electrical shock and were prone to drift in density slowly over time. With balanced wells, the very low tunnelling in the p-type bi-layer leads to a complete absence of all odd integers in both resistance and thermopower except for the v=1 state, ( v 1/2 in each layer) where v is the total Landau level filling factor. Unlike other FQHE features the v=1 state strengthens with increased density as inter-layer interactions increase in strength over intra-layer interactions. The state is also destroyed at a critical temperature, which is much lower than the measured activation temperature. This is taken as evidence for a finite temperature phase transition predicted for the bi-layer v=1. From the experimental observations, we construct a phase diagram for the state, which agree closely with theoretical predictions

  13. Anxious bliss: a case study of dissociation in a Mexican nun.

    Science.gov (United States)

    Lester, Rebecca J

    2008-03-01

    This is a case study of Celeste, postulant in a Roman Catholic convent in Mexico who experienced frequent episodes of leaving her body to commune with God. During these experiences, Celeste felt immersed in an ;incredibly beautiful profound silence' where ;time and space were broken.' But as much as Celeste craved these experiences, they also alarmed her; she was acutely aware that they might be indicative of psychological or neurological dysfunction. This article chronicles Celeste's struggles to make sense of her experiences in light of competing explanatory models. Her ultimate resolution suggests intriguing new directions for transcultural psychiatric research.

  14. Water dissociating on rigid Ni(100): A quantum dynamics study on a full-dimensional potential energy surface

    Science.gov (United States)

    Liu, Tianhui; Chen, Jun; Zhang, Zhaojun; Shen, Xiangjian; Fu, Bina; Zhang, Dong H.

    2018-04-01

    We constructed a nine-dimensional (9D) potential energy surface (PES) for the dissociative chemisorption of H2O on a rigid Ni(100) surface using the neural network method based on roughly 110 000 energies obtained from extensive density functional theory (DFT) calculations. The resulting PES is accurate and smooth, based on the small fitting errors and the good agreement between the fitted PES and the direct DFT calculations. Time dependent wave packet calculations also showed that the PES is very well converged with respect to the fitting procedure. The dissociation probabilities of H2O initially in the ground rovibrational state from 9D quantum dynamics calculations are quite different from the site-specific results from the seven-dimensional (7D) calculations, indicating the importance of full-dimensional quantum dynamics to quantitatively characterize this gas-surface reaction. It is found that the validity of the site-averaging approximation with exact potential holds well, where the site-averaging dissociation probability over 15 fixed impact sites obtained from 7D quantum dynamics calculations can accurately approximate the 9D dissociation probability for H2O in the ground rovibrational state.

  15. Dissociating early- and late-selection processes in recall: the mixed blessing of categorized study lists.

    Science.gov (United States)

    Guzel, Mehmet A; Higham, Philip A

    2013-07-01

    Two experiments are reported in which we used type-2 signal detection theory to separate the effects of semantic categorization on early- and late-selection processes in free and cued recall. In Experiment 1, participants studied cue-target pairs for which the targets belonged to two, six, or 24 semantic categories, and later the participants were required to recall the targets either with (cued recall) or without (free recall) the studied cues. A confidence rating and a report decision were also required, so that we could compute both forced-report quantity and metacognitive resolution (type-2 discrimination), which served as our estimates of early- and late-selection processes, respectively. Consistent with prior research, having fewer categories enhanced the early-selection process (in performance, two > six > 24 categories). However, in contrast, the late-selection process was impaired (24 > six = two categories). In Experiment 2, encoding of paired associates, for which the targets belonged to either two or 20 semantic categories, was manipulated by having participants either form interactive images or engage in rote repetition. Having fewer categories again was associated with enhanced early selection (two > 20 categories); this effect was greater for rote repetition than for interactive imagery, and greater for free recall than for cued recall. However, late selection again showed the opposite pattern (20 > two categories), even with interactive-imagery encoding, which formed distinctive, individuated memory traces. The results are discussed in terms of early- and late-selection processes in retrieval, as well as overt versus covert recognition.

  16. Dissociation in undergraduate students: disruptions in executive functioning.

    Science.gov (United States)

    Giesbrecht, Timo; Merckelbach, Harald; Geraerts, Elke; Smeets, Ellen

    2004-08-01

    The concept of dissociation refers to disruptions in attentional control. Attentional control is an executive function. Few studies have addressed the link between dissociation and executive functioning. Our study investigated this relationship in a sample of undergraduate students (N = 185) who completed the Dissociative Experiences Scale and the Random Number Generation Task. We found that minor disruptions in executive functioning were related to a subclass of dissociative experiences, notably dissociative amnesia and the Dissociative Experiences Scale Taxon. However, the two other subscales of the Dissociative Experiences Scale, measuring depersonalization and absorption, were unrelated to executive functioning. Our findings suggest that a failure to inhibit previous responses might contribute to the pathological memory manifestations of dissociation.

  17. Dissociative depression among women in the community.

    Science.gov (United States)

    Sar, Vedat; Akyüz, Gamze; Oztürk, Erdinç; Alioğlu, Firdevs

    2013-01-01

    This study screened the prevalence and correlates of dissociative disorders among depressive women in the general population. The Dissociative Disorders Interview Schedule and the posttraumatic stress disorder (PTSD) and borderline personality disorder sections of the Structured Clinical Interview for DSM-IV were administered to 628 women in 500 homes. The prevalence of current major depressive episode was 10.0%. Of the women, 26 (40.6%) had the lifetime diagnosis of a DSM-IV, dissociative disorder, yielding a prevalence of 4.1% for dissociative depression. This group was younger (mean age = 30.7 years) than the nondissociative depression women (mean age = 39.6 years). There was no difference between the 2 groups on comorbid somatization disorder, PTSD, or borderline personality disorder. Besides suicide attempts, the dissociative group was characterized by secondary features of dissociative identity disorder; Schneiderian symptoms; borderline personality disorder criteria; and extrasensory perceptions, including possession experiences. They reported suicidality, thoughts of guilt and worthlessness, diminished concentration and indecisiveness, and appetite and weight changes more frequently than the nondissociative group. Early cessation of school education and childhood sexual abuse were frequently reported by the dissociative depression group. With its distinct features, the concept of dissociative depression may facilitate understanding of treatment resistance in, development of better psychotherapy strategies for, and new thinking on the neurobiology and pharmacotherapy of depressive disorders.

  18. Indirect double photoionization of water

    Science.gov (United States)

    Resccigno, T. N.; Sann, H.; Orel, A. E.; Dörner, R.

    2011-05-01

    The vertical double ionization thresholds of small molecules generally lie above the dissociation limits corresponding to formation of two singly charged fragments. This gives the possibility of populating singly charged molecular ions by photoionization in the Franck-Condon region at energies below the lowest dication state, but above the dissociation limit into two singly charged fragment ions. This process can produce a superexcited neutral fragment that autoionizes at large internuclear separation. We study this process in water, where absorption of a photon produces an inner-shell excited state of H2O+ that fragments to H++OH*. The angular distribution of secondary electrons produced by OH* when it autoionizes produces a characteristic asymmetric pattern that reveals the distance, and therefore the time, at which the decay takes place. LBNL, Berkeley, CA, J. W. Goethe Universität, Frankfurt, Germany. Work performed under auspices of US DOE and supported by OBES, Div. of Chemical Sciences.

  19. A quantum chemical study of the N2H+ + e- → N2 + H reaction I: The linear dissociation path

    International Nuclear Information System (INIS)

    Talbi, D.

    2007-01-01

    A theoretical investigation of the dissociative recombination (DR) of linear N 2 H + (X 1 Σ g + ) to give N 2 + H has been undertaken because it is of interest for astrochemistry and also because it has been recently studied experimentally. Using state of the art quantum chemical methods, it is shown that the lowest 2 Σ repulsive state of N 2 H leading to the N 2 and H fragments in their ground electronic states does not cross the curve of the ion nor the one of the lowest N 2 H Rydberg state. This lowest 2 Σ repulsive state is very low in energy. Its curve passes below the 1 Σ N 2 H + state and below the lowest bound 2 Σ N 2 H states. However, it is also shown that there exist higher repulsive 2 Σ and 2 Δ states of N 2 H (the second and third repulsive states) crossing the ion curve. These states will lead to the formation of N 2 in its 3 Σ u + and 3 Δ u states. This study, the first of its type, shows that the DR of linear N 2 H + should involve the direct mechanism and that it should lead to N 2 in its first excited states. However this process may not be efficient for N 2 H + in its ground vibrational state (v = 0), a state in which it exists in the cold environment of the interstellar medium. For the DR to be efficient for N 2 H + in its ground v = 0 vibrational state, bent geometries of the ion might have to be considered

  20. Dissociative recombination of dications

    International Nuclear Information System (INIS)

    Seiersen, K.; Heber, O.; Jensen, M.J.; Safvan, C.P.; Andersen, L. H.

    2003-01-01

    Dissociative recombination (DR) of doubly-charged positive ions has been studied at the heavy ion storage ring ASTRID. Low-energy electrons were scattered on the dication of the N 2 molecule, and the absolute cross section was measured in the energy range of 10 -4 -50 eV. From the measured cross section, a thermal rate coefficient of 5.8x10 -7 cm 3 s -1 at 300 K was extracted. Furthermore, we present new results on the CO 2+ DR rate, and a summary and comparison of measured DR rate coefficients for both the singly and doubly-charged ions of CO, CO 2 , and N 2 is presented

  1. Case studies on the formation of chalcogenide self-assembled monolayers on surfaces and dissociative processes

    Directory of Open Access Journals (Sweden)

    Yongfeng Tong

    2016-02-01

    Full Text Available This report examines the assembly of chalcogenide organic molecules on various surfaces, focusing on cases when chemisorption is accompanied by carbon–chalcogen atom-bond scission. In the case of alkane and benzyl chalcogenides, this induces formation of a chalcogenized interface layer. This process can occur during the initial stages of adsorption and then, after passivation of the surface, molecular adsorption can proceed. The characteristics of the chalcogenized interface layer can be significantly different from the metal layer and can affect various properties such as electron conduction. For chalcogenophenes, the carbon–chalcogen atom-bond breaking can lead to opening of the ring and adsorption of an alkene chalcogenide. Such a disruption of the π-electron system affects charge transport along the chains. Awareness about these effects is of importance from the point of view of molecular electronics. We discuss some recent studies based on X-ray photoelectron spectroscopy that shed light on these aspects for a series of such organic molecules.

  2. Experimental study of heat transfer in regenerators-evaporators with dissociating coolant

    International Nuclear Information System (INIS)

    Kolykhan, L.I.; Golovnya, V.N.

    1983-01-01

    The results of experimental study of heat transfer in two parallel-flow regenerators-evaporators are given. One of the regenerators represents a counterflow heat exchanger of the tube-in-tube type with longitudinal roughness of the outside of the inner tube. In the second regenerator at the three intervals between roughness, recombiner-Chambers have been installed for fivefold increase of residence time of recombining warming gas mixture 2NO+O 2 reversible 2NO 2 reversible N 2 O 4 . The conducted experiments have shown that in the regenerators, having recombiners, more heat has been transfered (up to 15-20%) in comparison with conven=. tional construction at the expense of approximation of heating gas conditions to equitidrium and increasing of temperature drop. On the basis of conducted investigation the possibility of utilization of developed calculation methods is concluded for reliable design of regenerators of different types with equilibrium and non-equilibrium proceeding of chemical reactions in the coolant and with marked temperature heads between heating gas and heated medium

  3. Insights into the effect of coverage on CO adsorption and dissociation over Rh(1 0 0) surface: A theoretical study

    International Nuclear Information System (INIS)

    Zhao, Xiaojun; Zhang, Riguang; Ling, Lixia; Wang, Baojun

    2014-01-01

    Graphical abstract: - Highlights: • The adsorption energies gradually decrease with the increasing of CO coverage on Rh(1 0 0). • CO reaches the saturated adsorption with the coverage of 12/12 ML on Rh(1 0 0). • Both CO desorption and dissociation co-exist at the coverage less than or equal to 2/12 ML. • Only molecule CO adsorption is favored at the coverage greater than or equal to 3/12 ML. • Only molecule CO adsorption form exists in syngas conversion on Rh catalyst. - Abstract: The adsorption, dissociation and desorption of CO at different coverage over Rh(1 0 0) surface have been systematically investigated using density functional theory method together with the periodic slab model. Our results show that at the coverage less than or equal to 4/12 ML, CO favored the most stable bridge site adsorption, and the adsorption energies of CO have little difference; while at the coverage greater than or equal to 5/12 ML, the lateral repulsive interaction begins to affect the adsorption structures and the corresponding adsorption energies of adsorbed CO molecules, and the interaction will be stronger with the increasing of CO coverage, which leads to CO migration over Rh(1 0 0) surface when CO coverage is greater than or equal to 10/12 ML. The adsorption energies of these CO molecules will decrease successively until the saturated adsorption with the CO coverage of 12/12 ML. Further calculations on CO dissociation indicate that when CO coverage is greater than or equal to 3/12 ML, the dissociation of adsorbed CO molecules will be unfavorable both kinetically and thermodynamically, suggesting that only molecule CO adsorption are favored. Considering the catalytic activity of Rh(1 0 0) surface toward CO dissociation and the higher CO coverage under the continuous supply of CO in syngas conversion, it is to be expected that only molecule CO adsorption exist on Rh catalyst

  4. The Comparative Study of the Effects of Extremely Low Frequency Electromagnetic Fields and Infrasound on Water Molecule Dissociation and Generation of Reactive Oxygen Species

    Science.gov (United States)

    2008-11-01

    ISTC Project No. #1592P The Comparative Study of The Effects of Extremely Low Frequency Electromagnetic Fields and Infrasound on Water Molecule...performed under the agreement with the International Science and Technology Center ( ISTC ), Moscow. REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704...dissociation and generation of reactive oxygen spaces. 5a. CONTRACT NUMBER ISTC Registration No: A-1592p 5b. GRANT NUMBER 5c. PROGRAM ELEMENT

  5. Object-action dissociation: A voxel-based lesion-symptom mapping study on 102 patients after glioma removal

    Directory of Open Access Journals (Sweden)

    Alberto Pisoni

    Full Text Available Data concerning the neural basis of noun and verb processing are inconsistent. Some authors assume that action-verb processing is based on frontal areas while nouns processing relies on temporal regions; others argue that the circuits processing verbs and nouns are closely interconnected in a predominantly left-lateralized fronto-temporal-parietal network; yet, other researchers consider that the primary motor cortex plays a crucial role in processing action verbs. In the present study, one hundred and two patients with a tumour either in the right or left hemisphere were submitted to picture naming of objects and actions before and after surgery. To test the effect of specific brain regions in object and action naming, patients' lesions were mapped and voxel-lesion-symptom mapping (VLSM was computed. Behavioural results showed that left-brain damaged patients were significantly more impaired than right brain-damaged patients. The VLSM showed that these two grammatical classes are segregated in the left hemisphere. In particular, scores in naming of objects correlated with damage to the anterior temporal region, while scores in naming of actions correlated with lesions in the parietal areas and in the posterior temporal cortex. In addition, VLSM analyses carried out on non-linguistic tasks were not significant, confirming that the regions associated with deficits in object and action naming were not generally engaged in all cognitive tasks. Finally, the involvement of subcortical pathways was investigated and the inferior longitudinal fasciculus proved to play a role in object naming, while no specific bundle was identified for actions. Keywords: Object action dissociation, Temporal lesion, Frontal lesion, Voxel-based lesion symptom mapping

  6. The co-occurrence of PTSD and dissociation: differentiating severe PTSD from dissociative-PTSD.

    Science.gov (United States)

    Armour, Cherie; Karstoft, Karen-Inge; Richardson, J Don

    2014-08-01

    A dissociative-posttraumatic stress disorder (PTSD) subtype has been included in the DSM-5. However, it is not yet clear whether certain socio-demographic characteristics or psychological/clinical constructs such as comorbid psychopathology differentiate between severe PTSD and dissociative-PTSD. The current study investigated the existence of a dissociative-PTSD subtype and explored whether a number of trauma and clinical covariates could differentiate between severe PTSD alone and dissociative-PTSD. The current study utilized a sample of 432 treatment seeking Canadian military veterans. Participants were assessed with the Clinician Administered PTSD Scale (CAPS) and self-report measures of traumatic life events, depression, and anxiety. CAPS severity scores were created reflecting the sum of the frequency and intensity items from each of the 17 PTSD and 3 dissociation items. The CAPS severity scores were used as indicators in a latent profile analysis (LPA) to investigate the existence of a dissociative-PTSD subtype. Subsequently, several covariates were added to the model to explore differences between severe PTSD alone and dissociative-PTSD. The LPA identified five classes: one of which constituted a severe PTSD group (30.5 %), and one of which constituted a dissociative-PTSD group (13.7 %). None of the included, demographic, trauma, or clinical covariates were significantly predictive of membership in the dissociative-PTSD group compared to the severe PTSD group. In conclusion, a significant proportion of individuals report high levels of dissociation alongside their PTSD, which constitutes a dissociative-PTSD subtype. Further investigation is needed to identify which factors may increase or decrease the likelihood of membership in a dissociative-PTSD subtype group compared to a severe PTSD only group.

  7. On the nature of gallium species in gallium-modified mordenite and MFI zeolites. A comparative DRIFT study of carbon monoxide adsorption and hydrogen dissociation.

    Science.gov (United States)

    Serykh, Alexander I; Kolesnikov, Stanislav P

    2011-04-21

    The results of a DRIFT study of carbon monoxide molecular adsorption and hydrogen dissociative adsorption on gallium-modified mordenite and MFI (ZSM-5) zeolites are presented. It was found that in the reduced gallium-modified mordenite (Ga-MOR) both Ga(3+) and Ga(+) exchanged cations are present and can be detected by CO adsorption. Ga(3+) cations in Ga-MOR dissociatively adsorb molecular hydrogen at elevated temperatures, resulting in the formation of gallium hydride species and acidic hydroxyl groups. In the reduced Ga-MFI evacuated at 823 K under medium vacuum conditions only Ga(+) exchanged intrazeolite cations were detected. It was found, however, that Ga(3+) intrazeolite exchanged cations which form upon high-temperature disproportionation of Ga(+) cations in the reduced Ga-MFI and Ga-MOR can be stabilized by high-temperature oxidation of these zeolites.

  8. The dissociative chemisorption of methane on Ni(100) and Ni(111): Classical and quantum studies based on the reaction path Hamiltonian

    International Nuclear Information System (INIS)

    Mastromatteo, Michael; Jackson, Bret

    2013-01-01

    Electronic structure methods based on density functional theory are used to construct a reaction path Hamiltonian for CH 4 dissociation on the Ni(100) and Ni(111) surfaces. Both quantum and quasi-classical trajectory approaches are used to compute dissociative sticking probabilities, including all molecular degrees of freedom and the effects of lattice motion. Both approaches show a large enhancement in sticking when the incident molecule is vibrationally excited, and both can reproduce the mode specificity observed in experiments. However, the quasi-classical calculations significantly overestimate the ground state dissociative sticking at all energies, and the magnitude of the enhancement in sticking with vibrational excitation is much smaller than that computed using the quantum approach or observed in the experiments. The origin of this behavior is an unphysical flow of zero point energy from the nine normal vibrational modes into the reaction coordinate, giving large values for reaction at energies below the activation energy. Perturbative assumptions made in the quantum studies are shown to be accurate at all energies studied

  9. The Shutdown Dissociation Scale (Shut-D)

    Science.gov (United States)

    Schalinski, Inga; Schauer, Maggie; Elbert, Thomas

    2015-01-01

    The evolutionary model of the defense cascade by Schauer and Elbert (2010) provides a theoretical frame for a short interview to assess problems underlying and leading to the dissociative subtype of posttraumatic stress disorder. Based on known characteristics of the defense stages “fright,” “flag,” and “faint,” we designed a structured interview to assess the vulnerability for the respective types of dissociation. Most of the scales that assess dissociative phenomena are designed as self-report questionnaires. Their items are usually selected based on more heuristic considerations rather than a theoretical model and thus include anything from minor dissociative experiences to major pathological dissociation. The shutdown dissociation scale (Shut-D) was applied in several studies in patients with a history of multiple traumatic events and different disorders that have been shown previously to be prone to symptoms of dissociation. The goal of the present investigation was to obtain psychometric characteristics of the Shut-D (including factor structure, internal consistency, retest reliability, predictive, convergent and criterion-related concurrent validity). A total population of 225 patients and 68 healthy controls were accessed. Shut-D appears to have sufficient internal reliability, excellent retest reliability, high convergent validity, and satisfactory predictive validity, while the summed score of the scale reliably separates patients with exposure to trauma (in different diagnostic groups) from healthy controls. The Shut-D is a brief structured interview for assessing the vulnerability to dissociate as a consequence of exposure to traumatic stressors. The scale demonstrates high-quality psychometric properties and may be useful for researchers and clinicians in assessing shutdown dissociation as well as in predicting the risk of dissociative responding. PMID:25976478

  10. The Shutdown Dissociation Scale (Shut-D

    Directory of Open Access Journals (Sweden)

    Inga Schalinski

    2015-05-01

    Full Text Available The evolutionary model of the defense cascade by Schauer and Elbert (2010 provides a theoretical frame for a short interview to assess problems underlying and leading to the dissociative subtype of posttraumatic stress disorder. Based on known characteristics of the defense stages “fright,” “flag,” and “faint,” we designed a structured interview to assess the vulnerability for the respective types of dissociation. Most of the scales that assess dissociative phenomena are designed as self-report questionnaires. Their items are usually selected based on more heuristic considerations rather than a theoretical model and thus include anything from minor dissociative experiences to major pathological dissociation. The shutdown dissociation scale (Shut-D was applied in several studies in patients with a history of multiple traumatic events and different disorders that have been shown previously to be prone to symptoms of dissociation. The goal of the present investigation was to obtain psychometric characteristics of the Shut-D (including factor structure, internal consistency, retest reliability, predictive, convergent and criterion-related concurrent validity.A total population of 225 patients and 68 healthy controls were accessed. Shut-D appears to have sufficient internal reliability, excellent retest reliability, high convergent validity, and satisfactory predictive validity, while the summed score of the scale reliably separates patients with exposure to trauma (in different diagnostic groups from healthy controls.The Shut-D is a brief structured interview for assessing the vulnerability to dissociate as a consequence of exposure to traumatic stressors. The scale demonstrates high-quality psychometric properties and may be useful for researchers and clinicians in assessing shutdown dissociation as well as in predicting the risk of dissociative responding.

  11. Study on synthesis, kit formulation and chemical kinetics of dissociation of 99mTc labeled PnAO biotin complex

    International Nuclear Information System (INIS)

    Afshan, A.; Jafri, S.R.A.; Maecke, H.

    2004-01-01

    Full text: A bifunctional ligand of PnAO-biotin has recently been synthesized, with a better percentage yield of 63% in the presence of newly developed coupling agent 0-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexaflorophos phate (HATU). Then lyophilized kit with 150μg of PnAObiotin has been developed and labeled with high specific activity of technetium-99m (2500-3000MBq) to get maximum radiochemical purity of 99mTc-PnAO-biotin complex i.e. > 97%. The association of avidin and streptavidin is among the strongest known non-covalent protein ligand interaction Ka 1015 M-1 and 1013 M-1 respectively. We measured the dissociation rate constant of PnAO-biotin from avidin and streptavidin challenged with excess of cold biotin. For the separation of bound and free-labeled biotin we employed ultrafilteration technique. The results of these experiments demonstrated that the non-covalent binding between 99mTc-PnAO-biotin with avidin and 99mTc-PnAO-biotin with streptavidin is more than 99%. Both biotin-binding proteins exhibited a faster initial phase and the rate of dissociation of 99mTc-PnAO-biotin with avidin is found to be 8.2x10-8 at 250C and 2.6x10-7 at 370C while the rate of dissociation 99mTc-PnAO-biotin from streptavidin is found to be 6x10-7 at 250C and 1.06x10-6 at 370C. The in-vitro study of the kinetics of dissociation exhibits the strong interaction of 99mTc-PnAO-biotin complex with both proteins, which suggests that this bifunctional PnAO-biotin ligand can be used for tumor localization with monoclonal antibodies to achieve high tumor to non-tumor ratio. (author)

  12. The O-H Bond Dissociation Energies of Substituted Phenols and Proton Affinities of Substituted Phenoxide Ions: A DFT Study

    Directory of Open Access Journals (Sweden)

    Tadafumi Uchimaru

    2002-04-01

    Full Text Available Abstract: The accurate O-H bond dissociation enthalpies for a series of meta and para substituted phenols (X-C6H4-OH, X=H, F, Cl, CH3, OCH3, OH, NH2, CF3, CN, and NO2 have been calculated by using the (ROB3LYP procedure with 6-311G(d,p and 6-311++G(2df,2p basis sets. The proton affinities of the corresponding phenoxide ions (XC6H4-O- have also been computed at the same level of theory. The effect of change of substituent position on the energetics of substituted phenols has been analyzed. The correlations of Hammett’s substituent constants with the bond dissociation enthalpies of the O-H bonds of phenols and proton affinities of phenoxide ions have been explored.

  13. [Screening for major dissociative disorders with the FDS, the German version of the Dissociative Experience Scale].

    Science.gov (United States)

    Rodewald, Frauke; Gast, Ursula; Emrich, Hinderk M

    2006-06-01

    The prevalence of major dissociative disorders (dissociative identity disorder, DID and similar forms of dissociative disorder not otherwise specified, DDNOS) in clinical samples is about 5 %. Despite their frequency, major dissociative disorders are often overseen for a long time. Screening-scales have proved to be effective to support clinical diagnosis. The aim of this study was to test, whether the Fragebogen für dissoziative Symptome (FDS), the German version of the Dissociative Experiences Scale (DES), differentiates between patients with dissociative disorders, non-dissociative disorders and non-clinical controls. Additionally, an optimal FDS-cutoff for a more detailed differential-diagnostic evaluation of the dissociative symptomatology should be identified. 150 participants with DID (group DID: n = 44), DDNOS (DDNOS: n = 22), posttraumatic disorders (TRAUMA: n = 20), other non-dissociative disorders (non-TRAUMA: n = 34) and non-clinical controls (KG: n = 30) completed the FDS. In the five diagnostic groups, mean values were calculated and compared for the FDS, DES and FDS-20. Via receiver-operating-curves the cutoff-scores, which differentiated best between participants with and without major dissociative disorders, were identified. FDS, DES and FDS-20 differentiate significantly between patients with and without major dissociative disorders. For all scales, there were significant differences between the diagnostic groups, with mean-scores decreasing continuously from the groups DID to DDNOS and TRAUMA. Between the groups non-TRAUMA and KG tendencies were found in the predicted direction. The optimal cutoff-scores to differentiate between participants with and without major dissociative disorders were 13 (FDS/FDS-20) and 15 (DES). Using these cutoff-scores, at least 90 % of the patients with major dissociative disorders could be identified correctly (sensitivity). The specifity of the scales was 0.89 to 0.90. Screening for major dissociative disorders

  14. The Dissociation of Notions as a Tool for Justification: A study on practical reasoning in common law decisions

    OpenAIRE

    Ferry, Victor

    2012-01-01

    As an instance of the typical interaction between general argumentation theory and judicial argumentation practice, this paper uses the dissociation of notions, a concept elaborated by the former, possibly as from observations on the latter, to reexamine two well-known common law cases, in which the judges justify an interpretation grounded on the spirit of the law as opposed to a narrow interpretation of precedents. The author compares two current rival theoretical perspectives on the dissoc...

  15. Study of correlation of production and decay planes in π → 3π diffractive dissociation process on nuclei

    International Nuclear Information System (INIS)

    Efremov, A.V.; Ivan'shin, Yu.I.; Tkachev, L.G.; Zul'karneev, R.Ya.

    1998-01-01

    A large correlation of production and decay planes of (π - π + π - )-system in dissociation of π - -beam 40 GeV/c on nuclear targets was observed. The dependences of the correlation on atomic number, Feynman variable and transverse momentum as well as on invariant mass of the pion triple and neutral pion pair were investigated. It was shown that the phenomenon has a clear dynamic origin and resembles the single spin asymmetry behaviour

  16. A first principle study for the adsorption and absorption of carbon atom and the CO dissociation on Ir(100) surface

    Energy Technology Data Exchange (ETDEWEB)

    Erikat, I. A., E-mail: ihsanas@yahoo.com [Department of Physics, Jerash University, Jerash-26150 (Jordan); Hamad, B. A. [Department of Physics, The University of Jordan, Amman-11942 (Jordan)

    2013-11-07

    We employ density functional theory to examine the adsorption and absorption of carbon atom as well as the dissociation of carbon monoxide on Ir(100) surface. We find that carbon atoms bind strongly with Ir(100) surface and prefer the high coordination hollow site for all coverages. In the case of 0.75 ML coverage of carbon, we obtain a bridging metal structure due to the balance between Ir–C and Ir–Ir interactions. In the subsurface region, the carbon atom prefers the octahedral site of Ir(100) surface. We find large diffusion barrier for carbon atom into Ir(100) surface (2.70 eV) due to the strong bonding between carbon atom and Ir(100) surface, whereas we find a very small segregation barrier (0.22 eV) from subsurface to the surface. The minimum energy path and energy barrier for the dissociation of CO on Ir(100) surface are obtained by using climbing image nudge elastic band. The energy barrier of CO dissociation on Ir(100) surface is found to be 3.01 eV, which is appreciably larger than the association energy (1.61 eV) of this molecule.

  17. A first principle study for the adsorption and absorption of carbon atom and the CO dissociation on Ir(100) surface

    Science.gov (United States)

    Erikat, I. A.; Hamad, B. A.

    2013-11-01

    We employ density functional theory to examine the adsorption and absorption of carbon atom as well as the dissociation of carbon monoxide on Ir(100) surface. We find that carbon atoms bind strongly with Ir(100) surface and prefer the high coordination hollow site for all coverages. In the case of 0.75 ML coverage of carbon, we obtain a bridging metal structure due to the balance between Ir-C and Ir-Ir interactions. In the subsurface region, the carbon atom prefers the octahedral site of Ir(100) surface. We find large diffusion barrier for carbon atom into Ir(100) surface (2.70 eV) due to the strong bonding between carbon atom and Ir(100) surface, whereas we find a very small segregation barrier (0.22 eV) from subsurface to the surface. The minimum energy path and energy barrier for the dissociation of CO on Ir(100) surface are obtained by using climbing image nudge elastic band. The energy barrier of CO dissociation on Ir(100) surface is found to be 3.01 eV, which is appreciably larger than the association energy (1.61 eV) of this molecule.

  18. Adsorption and dissociation of H2S on Mo(1 0 0) surface by first-principles study

    International Nuclear Information System (INIS)

    Luo, Haijun; Cai, Jianqiu; Tao, Xiangming; Tan, Mingqiu

    2014-01-01

    Density-functional theory calculations had been used to investigate the adsorption and dissociation of H 2 S on Mo(1 0 0) surface. Adsorption mechanisms of H 2 S, HS, S and H on the Mo(1 0 0) surface were analyzed. H 2 S was found to be adsorbed at bridge, hollow and top sites with adsorption energies of −1.25, −1.03 and −0.92 eV, respectively. HS was strongly chemically absorbed at hollow, bridge and top sites with adsorption energies of −4.51, −4.08 and −3.45 eV, respectively, and sulfur and hydrogen preferred to be absorbed at hollow and bridge sites, respectively. In addition, potential energy profiles of H 2 S dissociation on Mo(1 0 0) had been constructed by a climbing image nudged elastic band method. Four possible dissociation pathways of the first H 2 S dehydrogenation were examined with reaction barriers of 0.28, 0.37, 0.075, and 0.21 eV, respectively, while the energy barrier to break the S-H bond of HS with or without hydrogen co-adsorption was almost the same low. This work showed that the decomposition of H 2 S on the molybdenum surface was kinetically and thermodynamically facile. Local densities of electronic states were further used to characterize the interaction between H 2 S and substrate.

  19. A first principle study for the adsorption and absorption of carbon atom and the CO dissociation on Ir(100) surface

    International Nuclear Information System (INIS)

    Erikat, I. A.; Hamad, B. A.

    2013-01-01

    We employ density functional theory to examine the adsorption and absorption of carbon atom as well as the dissociation of carbon monoxide on Ir(100) surface. We find that carbon atoms bind strongly with Ir(100) surface and prefer the high coordination hollow site for all coverages. In the case of 0.75 ML coverage of carbon, we obtain a bridging metal structure due to the balance between Ir–C and Ir–Ir interactions. In the subsurface region, the carbon atom prefers the octahedral site of Ir(100) surface. We find large diffusion barrier for carbon atom into Ir(100) surface (2.70 eV) due to the strong bonding between carbon atom and Ir(100) surface, whereas we find a very small segregation barrier (0.22 eV) from subsurface to the surface. The minimum energy path and energy barrier for the dissociation of CO on Ir(100) surface are obtained by using climbing image nudge elastic band. The energy barrier of CO dissociation on Ir(100) surface is found to be 3.01 eV, which is appreciably larger than the association energy (1.61 eV) of this molecule

  20. Speech-Language Dissociations, Distractibility, and Childhood Stuttering

    Science.gov (United States)

    Conture, Edward G.; Walden, Tedra A.; Lambert, Warren E.

    2015-01-01

    Purpose This study investigated the relation among speech-language dissociations, attentional distractibility, and childhood stuttering. Method Participants were 82 preschool-age children who stutter (CWS) and 120 who do not stutter (CWNS). Correlation-based statistics (Bates, Appelbaum, Salcedo, Saygin, & Pizzamiglio, 2003) identified dissociations across 5 norm-based speech-language subtests. The Behavioral Style Questionnaire Distractibility subscale measured attentional distractibility. Analyses addressed (a) between-groups differences in the number of children exhibiting speech-language dissociations; (b) between-groups distractibility differences; (c) the relation between distractibility and speech-language dissociations; and (d) whether interactions between distractibility and dissociations predicted the frequency of total, stuttered, and nonstuttered disfluencies. Results More preschool-age CWS exhibited speech-language dissociations compared with CWNS, and more boys exhibited dissociations compared with girls. In addition, male CWS were less distractible than female CWS and female CWNS. For CWS, but not CWNS, less distractibility (i.e., greater attention) was associated with more speech-language dissociations. Last, interactions between distractibility and dissociations did not predict speech disfluencies in CWS or CWNS. Conclusions The present findings suggest that for preschool-age CWS, attentional processes are associated with speech-language dissociations. Future investigations are warranted to better understand the directionality of effect of this association (e.g., inefficient attentional processes → speech-language dissociations vs. inefficient attentional processes ← speech-language dissociations). PMID:26126203

  1. DOUBLE CURVED SURFACE (DCS) - Case study in reinforced concrete

    DEFF Research Database (Denmark)

    Esteves, Luis Pedro; Henriques, Goncalo

    2007-01-01

    This paper deals with digital integration between design and fabrication in order to construct a complex double-curved concrete surface. This research focused on practical application of CNC technology to polyurethane (EPS), as an alternative to concrete formwork. The influence of specific EPS...

  2. Aspartame sensitivity? A double blind randomised crossover study.

    Directory of Open Access Journals (Sweden)

    Thozhukat Sathyapalan

    Full Text Available Aspartame is a commonly used intense artificial sweetener, being approximately 200 times sweeter than sucrose. There have been concerns over aspartame since approval in the 1980s including a large anecdotal database reporting severe symptoms. The objective of this study was to compare the acute symptom effects of aspartame to a control preparation.This was a double-blind randomized cross over study conducted in a clinical research unit in United Kingdom. Forty-eight individual who has self reported sensitivity to aspartame were compared to 48 age and gender matched aspartame non-sensitive individuals. They were given aspartame (100mg-containing or control snack bars randomly at least 7 days apart. The main outcome measures were acute effects of aspartame measured using repeated ratings of 14 symptoms, biochemistry and metabonomics.Aspartame sensitive and non-sensitive participants differed psychologically at baseline in handling feelings and perceived stress. Sensitive participants had higher triglycerides (2.05 ± 1.44 vs. 1.26 ± 0.84mmol/L; p value 0.008 and lower HDL-C (1.16 ± 0.34 vs. 1.35 ± 0.54 mmol/L; p value 0.04, reflected in 1H NMR serum analysis that showed differences in the baseline lipid content between the two groups. Urine metabonomic studies showed no significant differences. None of the rated symptoms differed between aspartame and control bars, or between sensitive and control participants. However, aspartame sensitive participants rated more symptoms particularly in the first test session, whether this was placebo or control. Aspartame and control bars affected GLP-1, GIP, tyrosine and phenylalanine levels equally in both aspartame sensitive and non-sensitive subjects.Using a comprehensive battery of psychological tests, biochemistry and state of the art metabonomics there was no evidence of any acute adverse responses to aspartame. This independent study gives reassurance to both regulatory bodies and the public that

  3. Aspartame sensitivity? A double blind randomised crossover study.

    Science.gov (United States)

    Sathyapalan, Thozhukat; Thatcher, Natalie J; Hammersley, Richard; Rigby, Alan S; Courts, Fraser L; Pechlivanis, Alexandros; Gooderham, Nigel J; Holmes, Elaine; le Roux, Carel W; Atkin, Stephen L

    2015-01-01

    Aspartame is a commonly used intense artificial sweetener, being approximately 200 times sweeter than sucrose. There have been concerns over aspartame since approval in the 1980s including a large anecdotal database reporting severe symptoms. The objective of this study was to compare the acute symptom effects of aspartame to a control preparation. This was a double-blind randomized cross over study conducted in a clinical research unit in United Kingdom. Forty-eight individual who has self reported sensitivity to aspartame were compared to 48 age and gender matched aspartame non-sensitive individuals. They were given aspartame (100mg)-containing or control snack bars randomly at least 7 days apart. The main outcome measures were acute effects of aspartame measured using repeated ratings of 14 symptoms, biochemistry and metabonomics. Aspartame sensitive and non-sensitive participants differed psychologically at baseline in handling feelings and perceived stress. Sensitive participants had higher triglycerides (2.05 ± 1.44 vs. 1.26 ± 0.84mmol/L; p value 0.008) and lower HDL-C (1.16 ± 0.34 vs. 1.35 ± 0.54 mmol/L; p value 0.04), reflected in 1H NMR serum analysis that showed differences in the baseline lipid content between the two groups. Urine metabonomic studies showed no significant differences. None of the rated symptoms differed between aspartame and control bars, or between sensitive and control participants. However, aspartame sensitive participants rated more symptoms particularly in the first test session, whether this was placebo or control. Aspartame and control bars affected GLP-1, GIP, tyrosine and phenylalanine levels equally in both aspartame sensitive and non-sensitive subjects. Using a comprehensive battery of psychological tests, biochemistry and state of the art metabonomics there was no evidence of any acute adverse responses to aspartame. This independent study gives reassurance to both regulatory bodies and the public that acute ingestion of

  4. NMR and XAS Study of Fe-Mo Double Perovskites

    International Nuclear Information System (INIS)

    Zajac, D.A.; Kapusta, C.; Borowiec, M.; Sikora, M.; Marquina, C.; Blasco, J.; Ibarra, M.R.

    2005-01-01

    The results of NMR and XAS measurements of the A 2 FeMoO 6 double perovskites (DP) (A 2 =Sr 2 , SrBa, Ba 2 , Ca 2 ) at the Fe and Mo K edges are reported and the information on the individual site electronic and magnetic properties is analysed. The compounds studied belong to the family of materials exhibiting a high field '' colossal '' magnetoresistance as well as a low field '' giant '' magnetoresistance. Magnetoresistive properties of the compounds arise from their half-metallicity, i.e. only one spin direction being populated in the conduction band, which consists of overlapping spin down 3d Fe, 2p O and 4d Mo electron bands. Within the model, a spin-down electron undergoes a fast hopping through unoccupied oxygen 2p orbitals between Fe 3+ (3d 5 - spin up) and Mo 6+ (4d 0 ) ionic cores. This mechanism implicates an anti-parallel coupling of the Fe and Mo spins and leads to non-integer magnetic moments and a metallic character below TC. The interaction, in analogy with the '' double exchange '' (DE) in manganites, is called '' double exchange-like '' interaction. The superexchange interaction (SE) is also expected to be present, resulting also in an anti-parallel coupling of 3d Fe 3+ and 4d Mo 5+ spins through occupied oxygen 2p orbitals. The insulating character of SE is connected with an increase of the tilt angle of the Fe-O-Mo bond, which is related to a change of the structural tolerance factor f and results in structural distortions. The molybdenum NMR measurements revealed the existence of a non-integer magnetic moment at Mo and Fe, which can be attributed to the DE-like interaction. However, experiments using Moessbauer spectroscopy have shown the existence of two Fe ionisation states - with integer (SE) and non integer (DE) magnetic moments. The 95 Mo and 97 Mo NMR measurements on A 2 FeMoO 6 (A 2 =Sr 2 , SrBa, Ba 2 , Ca 2 ) presented in this work show different values of the Mo hyperfine field and the corresponding magnetic moment. This is attributed

  5. Energy distribution in dissociations of polyatomic molecules

    International Nuclear Information System (INIS)

    Koernig, S.A.

    1989-01-01

    In this thesis studies are reported of fragmentation processes in polyatomic molecules. In order to find out which dessocaciation reactions take place, how they are brought about by the internal energy of the reactant, and to investigate the structure of the dissociating 'transition state', the fragment mass and the corresponding kinetic energy release (KER) are determined by differential translational spectroscopy using a position and time sensitive two-particle coincidence detector. The results are interpreted using the statistical theory of unimolecular dissociation. It turns out that the standard assumptions of the theory, especially in calculating KER-distributions, are not realistic in all molecules considered. Dissociation is induced by the neutralization with alkali metal vapour. In ch. 2 the experimental method and the analysis of the data (dissociation pathways, branching ratios and ε-d-distributions) are introduced and exemplified by measurements of cyclohexane, which represents the upper limit in precursor and fragment mass accessible in the apparatus. In ch. 3 a study is reported of the molecules methylchloride (CH 3 Cl) and the acetylradical (CH 3 CO). In spite of their similar geometric structures, completely different dissociation mechanisms have been found. Methylchloride dissociates via a repulsive state; acetyl radicals show energy scrambling. The energy distribution from dissociating acetyl exemplifies dynamical effects in the dissociation. In ch. 4 an investigation of a number of prototype hydrocarbons is presented. The dissociation pathways of several small linear alkanes indicate that neutralization takes place to unknown repulsive potentials, of which the position and steepness are determined from the kinetic energy release. (author). 118 refs.; 40 figs.; 5 tabs

  6. Wavepacket theory of collisional dissociation in molecules

    International Nuclear Information System (INIS)

    Kulander, K.

    1980-01-01

    An explicit integration scheme is used to solve the time dependent Schroedinger equation for wavepackets which model collisions in the collinear H + H 2 system. A realistic LEPS-type potential energy surface is used. Collision energies considered are above the dissociation threshold and probabilities for collision induced dissociation are reported. Also quantum mechanical state-to-state transition probabilities are generated. These results are compared to extensive classical trajectory calculations performed on this same system. The time evolution of the wavepacket densities is studied to understand the dynamics of the collinear collisional dissociation process

  7. Intolerance reaction after application of glucagon during double contrast studies

    International Nuclear Information System (INIS)

    Kainberger, F.; Fruehwald, F.; Schwaighofer, B.; Lindemayr, H.

    1986-01-01

    Whereas intolerance reactions against contrast media are a well-known hazard during radiologic procedures, intolerance reactions to other preparations used in radiology are rare. Glucagon, frequently used to induce gastrointestinal hypotonia, is said to have almost no side-effects. A case of anaphylactic reaction during double-contrast upper gastrointestinal examination is reported. Pseudoallergic reaction to propylparaben, a preservative agent in glucagon, is suspected. IgE-antibodies to glucagon could not be detected by RAST. (orig.) [de

  8. The co-occurrence of PTSD and dissociation: differentiating severe PTSD from dissociative-PTSD

    DEFF Research Database (Denmark)

    Armour, C.; Karstoft, K. I.; Richardson, J. D.

    2014-01-01

    A dissociative-posttraumatic stress disorder (PTSD) subtype has been included in the DSM-5. However, it is not yet clear whether certain socio-demographic characteristics or psychological/clinical constructs such as comorbid psychopathology differentiate between severe PTSD and dissociative-PTSD....... The current study investigated the existence of a dissociative-PTSD subtype and explored whether a number of trauma and clinical covariates could differentiate between severe PTSD alone and dissociative-PTSD. The current study utilized a sample of 432 treatment seeking Canadian military veterans. Participants...... were assessed with the Clinician Administered PTSD Scale (CAPS) and self-report measures of traumatic life events, depression, and anxiety. CAPS severity scores were created reflecting the sum of the frequency and intensity items from each of the 17 PTSD and 3 dissociation items. The CAPS severity...

  9. How Hot are Your Ions Really? A Threshold Collision-Induced Dissociation Study of Substituted Benzylpyridinium "Thermometer" Ions

    Science.gov (United States)

    Carpenter, John E.; McNary, Christopher P.; Furin, April; Sweeney, Andrew F.; Armentrout, P. B.

    2017-09-01

    The first absolute experimental bond dissociation energies (BDEs) for the main heterolytic bond cleavages of four benzylpyridinium "thermometer" ions are measured using threshold collision-induced dissociation in a guided ion beam tandem mass spectrometer. In this experiment, substituted benzylpyridinium ions are introduced into the apparatus using an electrospray ionization source, thermalized, and collided with Xe at varied kinetic energies to determine absolute cross-sections for these reactions. Various effects are accounted for, including kinetic shifts, multiple collisions, and internal and kinetic energy distributions. These experimentally measured 0 K BDEs are compared with computationally predicted values at the B3LYP-GD3BJ, M06-GD3, and MP2(full) levels of theory with a 6-311+G(2d,2p) basis set using vibrational frequencies and geometries determined at the B3LYP/6-311+G(d,p) level. Additional dissociation pathways are observed for nitrobenzylpyridinium experimentally and investigated using these same levels of theory. Experimental BDEs are also compared against values in the literature at the AM1, HF, B3LYP, B3P86, and CCSD(T) levels of theory. Of the calculated values obtained in this work, the MP2(full) level of theory with counterpoise corrections best reproduces the experimental results, as do the similar literature CCSD(T) values. Lastly, the survival yield method is used to determine the characteristic temperature (Tchar) of the electrospray source prior to the thermalization region and to confirm efficient thermalization. [Figure not available: see fulltext.

  10. Molecular-dynamics study of propane-hydrate dissociation: Fluctuation-dissipation and non-equilibrium analysis.

    Science.gov (United States)

    Ghaani, Mohammad Reza; English, Niall J

    2018-03-21

    Equilibrium and non-equilibrium molecular-dynamics (MD) simulations have been performed to investigate thermal-driven break-up of planar propane-hydrate interfaces in contact with liquid water over the 260-320 K range. Two types of hydrate-surface water-lattice molecular termination were adopted, at the hydrate edge with water, for comparison: a 001-direct surface cleavage and one with completed cages. Statistically significant differences in melting temperatures and initial break-up rates were observed between both interface types. Dissociation rates were observed to be strongly dependent on temperature, with higher rates at larger over-temperatures vis-à-vis melting. A simple coupled mass and heat transfer model, developed previously, was applied to fit the observed dissociation profiles, and this helps us to identify clearly two distinct hydrate-decomposition régimes; following a highly temperature-dependent break-up phase, a second well-defined stage is essentially independent of temperature, in which the remaining nanoscale, de facto two-dimensional system's lattice framework is intrinsically unstable. Further equilibrium MD-analysis of the two-phase systems at their melting point, with consideration of the relaxation times gleaned from the auto-correlation functions of fluctuations in a number of enclathrated guest molecules, led to statistically significant differences between the two surface-termination cases; a consistent correlation emerged in both cases between the underlying, non-equilibrium, thermal-driven dissociation rates sampled directly from melting with that from an equilibrium-MD fluctuation-dissipation approach.

  11. Coulomb drag in anisotropic systems: a theoretical study on a double-layer phosphorene

    NARCIS (Netherlands)

    Saberi-Pouya, S.; Vazifehshenas, T.; Farmanbar Gelepordsari, M.; Salavati-Fard, T.

    2016-01-01

    We theoretically study the Coulomb drag resistivity in a double-layer electron system with highly anisotropic parabolic band structure using Boltzmann transport theory. As an example, we consider a double-layer phosphorene on which we apply our formalism. This approach, in principle, can be tuned

  12. Dissociative Disorders Among Chinese Inpatients Diagnosed With Schizophrenia

    Science.gov (United States)

    Yu, Junhan; Ross, Colin A.; Keyes, Benjamin B.; Li, Ying; Dai, Yunfei; Zhang, Tianhong; Wang, Lanlan; Fan, Qing; Xiao, Zeping

    2010-01-01

    The purpose of the study was to assess the prevalence of dissociative disorders in a sample of Chinese psychiatric inpatients. Participants in the study consisted of 569 consecutively admitted inpatients at Shanghai Mental Health Center, China, of whom 84.9% had a clinical diagnosis of schizophrenia based on the Chinese Classification and Diagnostic Criteria for Mental Disorders, Version 3 (CCMD-3). All participants completed a self-report measure of dissociation, the Dissociative Experiences Scale (DES) and none had a prior diagnosis of a dissociative disorder. Ninety-six randomly selected participants were interviewed with a structured interview, the Dissociative Disorders Interview Schedule (DDIS) and a clinical interview. These 96 patients did not differ significantly from the 473 patients who were not interviewed on any demographic measures or on the self-report measure dissociation. A total of 28 (15.3%, after weighting of the data) patients received a clinical diagnosis of a dissociative disorder based on DSM-IV-TR criteria. Dissociative identity disorder was diagnosed in 2 (0.53%, after weighting) patients. Compared to the patients without a dissociative disorder, patients with dissociative disorders were significantly more likely to report childhood abuse (57.1% versus 22.1%), but the two groups did not differ significantly on any demographic measures. Dissociative disorders were readily identified in an inpatient psychiatric population in China. PMID:20603768

  13. Malingering dissociative identity disorder: objective and projective assessment.

    Science.gov (United States)

    Labott, Susan M; Wallach, Heather R

    2002-04-01

    Verification of dissociative identity disorder presents challenges given the complex nature of the illness. This study addressed the concern that this disorder can be successfully malingered on objective and projective psychological tests. 50 undergraduate women were assigned to a Malingering or a Control condition, then completed the Rorschach Inkblot Test and the Dissociative Experiences Scale II. The Malingering group were asked to simulate dissociative identity disorder; controls received instructions to answer all materials honestly. Analysis indicated that malingerers were significantly more likely to endorse dissociative experiences on the Dissociative Experiences Scale II in the range common to patients with diagnosed dissociative identity disorder. However, on the Rorschach there were no significant differences between the two groups. Results suggest that the assessment of dissociative identity disorder requires a multifaceted approach with both objective and projective assessment tools. Research is needed to assess these issues in clinical populations.

  14. Teaching Chinese psychiatrists to make reliable dissociative disorder diagnoses.

    Science.gov (United States)

    Fan, Qing; Yu, Junhan; Ross, Colin A; Keyes, Benjamin B; Dai, Yunfei; Zhang, Tianhong; Wang, Lanlan; Xiao, Zeping

    2011-09-01

    The aim of the study was to assess the outcome of an educational effort by two North American experts in dissociative disorders to teach Chinese psychiatrists to make reliable dissociative disorder diagnoses. In the final phase of the educational effort, 569 patients at Shanghai Mental Health Center completed the Chinese version of the Dissociative Experiences Scale (DES). Patients were then randomly selected in different proportions according to their DES scores: 96 selected patients were then assessed with the Dissociative Disorders Interview Schedule (DDIS) and clinical diagnostic interviews based on DSM-IV criteria. According to the clinical diagnostic interviews, 28 (4.9%) patients were diagnosed as having dissociative disorders. Agreement between the American experts and Chinese psychiatrists for presence or absence of a dissociative disorder was 0.75 using Cohen's kappa. Dissociative disorders can be diagnosed in China with good inter-rater reliability. The authors describe the steps taken to achieve this outcome.

  15. Adsorption and possible dissociation of glucose by the [BN fullerene-B6]- magnetic nanocomposite. In silico studies

    Science.gov (United States)

    Anota, E. Chigo; Villanueva, M. Salazar; Shakerzadeh, E.; Castro, M.

    2018-02-01

    The adsorption, activation and possible dissociation of the glucose molecule on the magnetic [BN fullerene-B6]- system is performed by means of density functional theory calculations. Three models of magnetic nanocomposites were inspected: i) pristine BN fullerene, BN fullerene functionalized with a magnetic B6 cluster which generates two structures: ii) pyramidal (P) and iii) triangular (T). Chemical interactions of glucose appear for all these cases; however, for the BNF:B6(T)—glucose system, the interaction generates an effect of dissociation on glucose, due to the magnetic effects, since it has high spin multiplicity. The latter nanocomposite shows electronic behavior like-conductor and like-semi-conductor for the P and T geometries, respectively. Intrinsic magnetism associated to values of 1.0 magneton bohr (µB) for the pyramidal and 5.0 µB for the triangular structure, high polarity, and low-chemical reactivity are found for these systems. These interesting properties make these functionalized fullerenes a good option for being used as nano-vehicles for drug delivery. These quantum descriptors remain invariant when the [BN]-fullerene and [BNF:B6 (P) or (T)]- nanocomposites are interacting with the glucose molecule. According to the determined adsorption energy, chemisorption regimes occur in both the phases: gas and aqueous medium.

  16. Hydrogenation of graphene nanoflakes and C-H bond dissociation of hydrogenated graphene nanoflakes: a density functional theory study

    Institute of Scientific and Technical Information of China (English)

    Sheng Tao; Hui-Ting Liu; Liu-Ming Yan; Bao-Hua Yue; Ai-Jun Li

    2017-01-01

    The Gibbs free energy change for the hydrogenation of graphene nanoflakes Cn (n =24,28,30 and 32) and the C-H bond dissociation energy of hydrogenated graphene nanoflakes CnHm (n =24,28,30 and 32;and m =1,2 and 3) are evaluated using density functional theory calculations.It is concluded that the graphene nanoflakes and hydrogenated graphene nanoflakes accept the ortharyne structure with peripheral carbon atoms bonded via the most triple bonds and leaving the least unpaired dangling electrons.Five-membered rings are formed at the deep bay sites attributing to the stabilization effect from the pairing of dangling electrons.The hydrogenation reactions which eliminate one unpaired dangling electron and thus decrease the overall multiplicity of the graphene nanoflakes or hydrogenated graphene nanoflakes are spontaneous with negative or near zero Gibbs free energy change.And the resulting C-H bonds are stable with bond dissociation energy in the same range as those of aromatic compounds.The other C-H bonds are not as stable attributing to the excessive unpaired dangling electrons being filled into the C-H anti-bond orbital.

  17. Dissociation and decay of ultracold sodium molecules

    International Nuclear Information System (INIS)

    Mukaiyama, T.; Abo-Shaeer, J.R.; Xu, K.; Chin, J.K.; Ketterle, W.

    2004-01-01

    The dissociation of ultracold molecules was studied by ramping an external magnetic field through a Feshbach resonance. The observed dissociation energies directly yielded the strength of the atom-molecule coupling. They showed nonlinear dependence on the ramp speed. This was explained by a Wigner threshold law which predicts that the decay rate of the molecules above threshold increases with the density of states. In addition, inelastic molecule-molecule and molecule-atom collisions were characterized

  18. Experimental study of angular dependence in double photon Compton scattering

    International Nuclear Information System (INIS)

    Sandhu, B.S.; Dewan, R.; Saddi, M.B.; Singh, B.; Ghumman, B.S.

    2000-01-01

    The collision differential cross-section and energy of one of the final photons for double photon Compton scattering have been measured as a function of scattering angle θ 1 . The incident photon energy is 0.662 MeV and thin aluminium foils are used as a scatterer. The two simultaneously emitted photons in this higher order process are detected in coincidence using two NaI(Tl) scintillation spectrometers and 30 ns timing electronics. The measured values for energy and collision differential cross-section agree with theory within experimental estimated error. The present data provide information of angular dependence in this higher order process

  19. Schematic model studies of double beta decay processes

    International Nuclear Information System (INIS)

    Civitarese, O.

    1996-01-01

    Some features of the nuclear matrix elements, for double beta decay transitions to a final ground state and to a final excited one and two-quadrupole phonon states, are presented and discussed in the framework of a schematic model. The competition between spin-flip and non-spin-flip transitions on the relevant nuclear matrix elements, the effects due to proton-neutron pairing correlations and the effects due to the inclusion of exchange terms in the QRPA matrix are discussed. (Author)

  20. Role of dispersion corrected hybrid GGA class in accurately calculating the bond dissociation energy of carbon halogen bond: A benchmark study

    Science.gov (United States)

    Kosar, Naveen; Mahmood, Tariq; Ayub, Khurshid

    2017-12-01

    Benchmark study has been carried out to find a cost effective and accurate method for bond dissociation energy (BDE) of carbon halogen (Csbnd X) bond. BDE of C-X bond plays a vital role in chemical reactions, particularly for kinetic barrier and thermochemistry etc. The compounds (1-16, Fig. 1) with Csbnd X bond used for current benchmark study are important reactants in organic, inorganic and bioorganic chemistry. Experimental data of Csbnd X bond dissociation energy is compared with theoretical results. The statistical analysis tools such as root mean square deviation (RMSD), standard deviation (SD), Pearson's correlation (R) and mean absolute error (MAE) are used for comparison. Overall, thirty-one density functionals from eight different classes of density functional theory (DFT) along with Pople and Dunning basis sets are evaluated. Among different classes of DFT, the dispersion corrected range separated hybrid GGA class along with 6-31G(d), 6-311G(d), aug-cc-pVDZ and aug-cc-pVTZ basis sets performed best for bond dissociation energy calculation of C-X bond. ωB97XD show the best performance with less deviations (RMSD, SD), mean absolute error (MAE) and a significant Pearson's correlation (R) when compared to experimental data. ωB97XD along with Pople basis set 6-311g(d) has RMSD, SD, R and MAE of 3.14 kcal mol-1, 3.05 kcal mol-1, 0.97 and -1.07 kcal mol-1, respectively.

  1. Hypnotic suggestibility, cognitive inhibition, and dissociation.

    Science.gov (United States)

    Dienes, Zoltán; Brown, Elizabeth; Hutton, Sam; Kirsch, Irving; Mazzoni, Giuliana; Wright, Daniel B

    2009-12-01

    We examined two potential correlates of hypnotic suggestibility: dissociation and cognitive inhibition. Dissociation is the foundation of two of the major theories of hypnosis and other theories commonly postulate that hypnotic responding is a result of attentional abilities (including inhibition). Participants were administered the Waterloo-Stanford Group Scale of Hypnotic Susceptibility, Form C. Under the guise of an unrelated study, 180 of these participants also completed: a version of the Dissociative Experiences Scale that is normally distributed in non-clinical populations; a latent inhibition task, a spatial negative priming task, and a memory task designed to measure negative priming. The data ruled out even moderate correlations between hypnotic suggestibility and all the measures of dissociation and cognitive inhibition overall, though they also indicated gender differences. The results are a challenge for existing theories of hypnosis.

  2. Dissociation and memory fragmentation in post-traumatic stress disorder: an evaluation of the dissociative encoding hypothesis.

    Science.gov (United States)

    Bedard-Gilligan, Michele; Zoellner, Lori A

    2012-01-01

    Several prominent theories of post-traumatic stress disorder (PTSD) posit that peritraumatic dissociation results in insufficient encoding of the trauma memory and that persistent dissociation prevents memory elaboration, resulting in memory fragmentation and PTSD. In this review we summarise the empirical literature on peritraumatic and trait dissociation and trauma narrative fragmentation as measured by meta-memory and rater/objective coding. Across 16 studies to date, the association between dissociation and fragmentation was most prominent when examining peritraumatic dissociation and patient's own ratings of memory fragmentation. This relationship did not hold when examining trait dissociation or rater-coded or computer-generated measures of fragmentation. Thus initial evidence points more towards a strong self-reported association between constructs that is not supported on more objective fragmentation coding. Measurement overlap, construct ambiguity, and exclusion of potential confounds may underlie lack of a strong association between dissociation and objective-rated fragmentation.

  3. Studying the muon background component in the Double Chooz experiment

    Energy Technology Data Exchange (ETDEWEB)

    Dietrich, Dennis

    2013-03-28

    The reactor anti-neutrino experiment Double Chooz (DC) will measure the third neutrino mixing angle θ{sub 13} with very high precision. This mixing angle is connected to fundamental questions in particle physics beyond the current Standard Model. In DC neutrinos are detected via the Inverse Beta Decay reaction, which provides a clean signal distinguishable from most backgrounds. However, as neutrino interactions in the detector are very rare and an interfering muon background is present, a proper understanding and reduction of this background is mandatory. This is crucial because muons create fast neutrons and βn-emitters which lead to background capable of mimicking the neutrino interaction in the detector. This thesis covers different analysis topics related to the cosmic ray muon background at the DC far site. The thesis covers the identification of muons, the applied rejection technique and the determination of the muon rate at DC far site. Utilizing the muon rejection cuts of the neutrino analysis a muon rate of 13 s{sup -1} in the Inner Detector (ID) and of 46 s{sup -1} in the Inner Muon Veto (IV) was found. The efficiency of the IV to identify and reject cosmic ray muons was measured and a value greater than 99.97% has been found. The stability of the determined muon rates was examined and a seasonal modulation was found, compatible with a variation of the temperature profile of the atmosphere over the year. The parameter describing the strength between the relationship of temperature and muon rate change, the effective temperature coefficient was obtained: αT=0.39±0.01(stat.)±0.02(syst.). This gave the opportunity to measure the atmospheric kaon to pion ratio with the DC far detector which was found to be r(K/π)=0.14±0.06. Additional variations of muon rate with surface pressure were found and the barometric coefficient describing this effect was measured as βp=-0.59±0.20(stat.)±0.10(syst.) permille /mbar. Another central theme of this work was

  4. Studying the muon background component in the Double Chooz experiment

    International Nuclear Information System (INIS)

    Dietrich, Dennis

    2013-01-01

    The reactor anti-neutrino experiment Double Chooz (DC) will measure the third neutrino mixing angle θ 13 with very high precision. This mixing angle is connected to fundamental questions in particle physics beyond the current Standard Model. In DC neutrinos are detected via the Inverse Beta Decay reaction, which provides a clean signal distinguishable from most backgrounds. However, as neutrino interactions in the detector are very rare and an interfering muon background is present, a proper understanding and reduction of this background is mandatory. This is crucial because muons create fast neutrons and βn-emitters which lead to background capable of mimicking the neutrino interaction in the detector. This thesis covers different analysis topics related to the cosmic ray muon background at the DC far site. The thesis covers the identification of muons, the applied rejection technique and the determination of the muon rate at DC far site. Utilizing the muon rejection cuts of the neutrino analysis a muon rate of 13 s -1 in the Inner Detector (ID) and of 46 s -1 in the Inner Muon Veto (IV) was found. The efficiency of the IV to identify and reject cosmic ray muons was measured and a value greater than 99.97% has been found. The stability of the determined muon rates was examined and a seasonal modulation was found, compatible with a variation of the temperature profile of the atmosphere over the year. The parameter describing the strength between the relationship of temperature and muon rate change, the effective temperature coefficient was obtained: αT=0.39±0.01(stat.)±0.02(syst.). This gave the opportunity to measure the atmospheric kaon to pion ratio with the DC far detector which was found to be r(K/π)=0.14±0.06. Additional variations of muon rate with surface pressure were found and the barometric coefficient describing this effect was measured as βp=-0.59±0.20(stat.)±0.10(syst.) permille /mbar. Another central theme of this work was the extrapolation

  5. Subtypes of dissociative (conversion) disorder in two tertiary hospitals in Bangladesh.

    Science.gov (United States)

    Ahsan, M S; Mullick, S I; Sobhan, M A; Khanam, M; Nahar, J S; Salam, M A; Ali, R; Islam, M; Kabir, M S

    2010-01-01

    Dissociative (conversion) disorders are common among the patients attending in and out patients of Psychiatry Department of tertiary hospitals in Bangladesh. This study was done to see the subtypes of dissociative (conversion) disorder according to International Classification of Diseases, Tenth Revision (ICD-10). This is a descriptive, cross sectional study done on 100 consecutive patients from the Departments of Psychiatry, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka and Dhaka Medical College Hospital (DMCH). Study period was July 2005 to June 2006. Among the patients of dissociative (conversion) disorder, mixed dissociative (conversion) disorder was found highest 34%, followed by dissociative convulsion 33%, dissociative motor disorders 19%, dissociative anaesthesia and sensory loss 5%, dissociative amnesia 4%, dissociative fugue 3%. However, the researcher did not find any multiple personality disorder which is relatively common in North America. This finding reflected that there are differences in prevalence of sub types of dissociative disorders in Bangladesh and Western countries.

  6. Study in regularities in the formation of double stranded DNA breaks in irradiated rat thymocytes

    International Nuclear Information System (INIS)

    Ivannik, B.P.; ProskuryakoV, S.Ya.; Ryabchenko, N.I.

    1979-01-01

    Using low-gradient viscosimetry of neutral detergent nuclear lysates a study was made of postradiation changes in the molecular weight of double-stranded DNA of thymocytes. It was established that 375 eV are needed for one double-stranded break to appear, and a dose of 1 rad is required for 0.275 double-stranded break to occur at the site of DNA with m.w. 10 12 dalton. The repair of double-stranded breaks is only observed when rats are exposed to a dose of 500 R. It is assumed that the absence of repair of double-stranded DNA breaks and the presence of secondary postradiation degradation of DNA are responsible for thymocyte death

  7. Adsorption and dissociation of H{sub 2}S on Mo{sub 2}C(001) surface-A first-principle study

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Dianling; Guo, Wenyue, E-mail: wyguo@upc.edu.cn; Liu, Yunjie; Chi, Yuhua

    2015-10-01

    Highlights: • Adsorption of reactants, intermediates involved was investigated. • The Mulliken charge and partial density of states were analyzed. • The dissociation mechanism was investigated. • The optimal pathway for the dissociation of H{sub 2}S on the Mo{sub 2}C(001) surface was given. - Abstract: The adsorption and decomposition reaction mechanisms of H{sub 2}S on Mo{sub 2}C(001) has been systematically studied using self-consistent periodic density functional theory. Results show that the molecular of H{sub 2}S is adsorbed either on the Mo top site or bridge site. Mulliken population analysis and density of states for H{sub 2}S/Mo-terminated Mo{sub 2}C(001) adsorption system are examined to confirm the adsorption mechanism of H{sub 2}S with the Mo{sub 2}C(001) surface, which can involve the donation of charge from the “s lone pair electrons” that are LUMO orbitals into the surface and the back donation of electrons from the surface into the HOMO orbital. The optimal pathway for the dissociation of H{sub 2}S on the Mo{sub 2}C(001) surface can be H{sub 2}S{sub top} → SH{sub fcc} + H{sub fcc} → S{sub fcc} + H{sub fcc} + H{sub fcc}. The first step is the rate-determining step because it has the smallest rate constant among the possible reactions pathways.

  8. Gas phase 1H NMR studies and kinetic modeling of dihydrogen isotope equilibration catalyzed by Ru-nanoparticles under normal conditions: dissociative vs. associative exchange.

    Science.gov (United States)

    Limbach, Hans-Heinrich; Pery, Tal; Rothermel, Niels; Chaudret, Bruno; Gutmann, Torsten; Buntkowsky, Gerd

    2018-04-25

    The equilibration of H2, HD and D2 between the gas phase and surface hydrides of solid organic-ligand-stabilized Ru metal nanoparticles has been studied by gas phase 1H NMR spectroscopy using closed NMR tubes as batch reactors at room temperature and 800 mbar. When two different nanoparticle systems, Ru/PVP (PVP ≡ polyvinylpyrrolidone) and Ru/HDA (HDA ≡ hexadecylamine) were exposed to D2 gas, only the release of HD from the hydride containing surface could be detected in the initial stages of the reaction, but no H2. In the case of Ru/HDA also the reverse experiment was performed where surface deuterated nanoparticles were exposed to H2. In that case, the conversion of H2 into gaseous HD was detected. In order to analyze the experimental kinetic and spectroscopic data, we explored two different mechanisms taking into account potential kinetic and equilibrium H/D isotope effects. Firstly, we explored the dissociative exchange mechanism consisting of dissociative adsorption of dihydrogen, fast hydride surface diffusion and associative desorption of dihydrogen. It is shown that if D2 is the reaction partner, only H2 will be released in the beginning of the reaction, and HD only in later reaction stages. The second mechanism, dubbed here associative exchange consists of the binding of dihydrogen to Ru surface atoms, followed by a H-transfer to or by H-exchange with an adjacent hydride site, and finally of the associative desorption of dihydrogen. In that case, in the exchange with D2, only HD will be released in the beginning of the reaction. Our experimental results are not compatible with the dissociative exchange but can be explained in terms of the associative exchange. Whereas the former will dominate at low temperatures and pressures, the latter will prevail around room temperature and normal pressures where transition metal nanoparticles are generally used as reaction catalysts.

  9. Laser ionization and dissociation of hydrogen

    International Nuclear Information System (INIS)

    Buck, J.D.

    1987-01-01

    Experiments undertaken to further characterize the spectroscopic and photophysical properties of some important excited singlet states of molecular hydrogen and its deuterium isotopes are described. Attention was centered on high vibrational levels of the B, C, and B' states within about 1000 cm -1 of the second dissociation limit. A double-resonance excitation scheme was needed to access levels with a large average bond distance from the ground state. Two-photon absorption of tunable uv-laser radiation-pumped ground-state hydrogen molecules into selected rovibronic levels of the metastable EF double-minimum electronic state. A second tunable near-IR probe laser was scanned to generate ions by resonant multiphoton ionization, where the resonant levels were provided by B, C, B', and other levels near the dissociation limit. New information was obtained regarding line shapes and intensities. Time-of-flight ion mass selection permitted observation of additional excitation channels with dissociation superimposed on the ionization process to produce protons

  10. A multi-reference singles and doubles configuration interaction determination in the dissociation energy and vibrational levels of the BeF molecules in the X2Σ + state

    International Nuclear Information System (INIS)

    Machado, F.B.C.; Ornellas, F.R.

    1988-10-01

    An accurate potential energy curve for the BeF molecule in the X 2 Σ + state is calculated within the MRSDCI approach. Vibrational level spacings and the dissociation energy are reported. Agreement with the available experimental spacings is 15 cm -1 on the average. The theoretically computed D o , 5.92 eV, favors the experimental value of 5.85 eV over the higher value of 6.26 eV. Arguments are also presented that show why the value obtained by the Birge-Sponer linear extrapolation is accidentally a good one. (author) [pt

  11. Dissociation and psychosis in dissociative identity disorder and schizophrenia.

    Science.gov (United States)

    Laddis, Andreas; Dell, Paul F

    2012-01-01

    Dissociative symptoms, first-rank symptoms of schizophrenia, and delusions were assessed in 40 schizophrenia patients and 40 dissociative identity disorder (DID) patients with the Multidimensional Inventory of Dissociation (MID). Schizophrenia patients were diagnosed with the Structured Clinical Interview for the DSM-IV Axis I Disorders; DID patients were diagnosed with the Structured Clinical Interview for DSM-IV Dissociative Disorders-Revised. DID patients obtained significantly (a) higher dissociation scores; (b) higher passive-influence scores (first-rank symptoms); and (c) higher scores on scales that measure child voices, angry voices, persecutory voices, voices arguing, and voices commenting. Schizophrenia patients obtained significantly higher delusion scores than did DID patients. What is odd is that the dissociation scores of schizophrenia patients were unrelated to their reports of childhood maltreatment. Multiple regression analyses indicated that 81% of the variance in DID patients' dissociation scores was predicted by the MID's Ego-Alien Experiences Scale, whereas 92% of the variance in schizophrenia patients' dissociation scores was predicted by the MID's Voices Scale. We propose that schizophrenia patients' responses to the MID do not index the same pathology as do the responses of DID patients. We argue that neither phenomenological definitions of dissociation nor the current generation of dissociation instruments (which are uniformly phenomenological in nature) can distinguish between the dissociative phenomena of DID and what we suspect are just the dissociation-like phenomena of schizophrenia.

  12. Study of the double charge-changing collision cross-sections of H+, D+, Li+ ions with organic molecules in the energy range 10-50 keV

    International Nuclear Information System (INIS)

    Farrokhi, S.

    1966-01-01

    The variation of the double charge-changing collision cross-sections of H + , D + , Li + ions with organic molecules (CH 4 , C 2 H 6 , C 3 H 8 , C 4 H 10 ) in the energy range 10-50 keV has been studied. Several maximums for σ 1-1 = f(E) have been shown. Their existence should be explained by the different possibilities of dissociating the target-molecules. The position of the maximums, for the H + → H - and D + → D - reactions is in good agreement with that defined by the Massey adiabatic relation. (author) [fr

  13. The statistical study of Chorus waves using the Double star TC1 data

    Science.gov (United States)

    Yearby, K.; Aryan, H.; Balikhin, M. A.; Krasnoselskikh, V.; Agapitov, O. V.

    2013-12-01

    The Double star satellite was launched on 29 December 2003 into an equatorial elliptical orbit with a perigee of 570km and an apogee of 78970km and an inclination of 28.5°. The satellite operated until 14 October 2007. The Double star TC1 data provides extensive coverage of the inner magnetosphere regions in the range of L shells >1.1L*, and a wide range of latitudes. This study presents a detailed statistical study of the Chorus waves during 4 years of the Double star operation.

  14. Dissociative Identity Disorder

    Science.gov (United States)

    Schmidt, Tom

    2007-01-01

    Few psychological disorders in the Diagnostic Statistical Manual have generated as much controversy as Dissociative Identity Disorder (DID). For the past 35 years diagnoses of DID, previously referred to as Multiple Personality Disorder (MPD), have increased exponentially, causing various psychological researchers and clinicians to question the…

  15. Electron-Impact Ionization and Dissociative Ionization of Biomolecules

    Science.gov (United States)

    Huo, Winifred M.; Chaban, Galina M.; Dateo, Christopher E.

    2006-01-01

    It is well recognized that secondary electrons play an important role in radiation damage to humans. Particularly important is the damage of DNA by electrons, potentially leading to mutagenesis. Molecular-level study of electron interaction with DNA provides information on the damage pathways and dominant mechanisms. Our study of electron-impact ionization of DNA fragments uses the improved binary-encounter dipole model and covers DNA bases, sugar phosphate backbone, and nucleotides. An additivity principle is observed. For example, the sum of the ionization cross sections of the separate deoxyribose and phosphate fragments is in close agreement with the C3(sup prime)- and C5 (sup prime)-deoxyribose-phospate cross sections, differing by less than 5%. Investigation of tandem double lesion initiated by electron-impact dissociative ionization of guanine, followed by proton reaction with the cytosine in the Watson-Crick pair, is currently being studied to see if tandem double lesion can be initiated by electron impact. Up to now only OH-induced tandem double lesion has been studied.

  16. Neurophysiological correlates of dissociative symptoms

    NARCIS (Netherlands)

    Kruijs, van der S.J.M.; Bodde, N.M.G; Carrette, E.C.B.; Lazeron, R.H.C; Vonck, K.E.J.; Boon, P.A.J.M.; Langereis, G.R.; Cluitmans, P.J.M.; Feijs, L.M.G.; Hofman, P.A.M.; Backes, W.H.; Jansen, J.F.A.; Aldenkamp, A.P.

    2014-01-01

    Objective: Dissociation is a mental process with psychological and somatoform manifestations, which is closely related to hypnotic suggestibility and essentially shows the ability to obtain distance from reality. An increased tendency to dissociate is a frequently reported characteristic of patients

  17. Objective documentation of child abuse and dissociation in 12 murderers with dissociative identity disorder.

    Science.gov (United States)

    Lewis, D O; Yeager, C A; Swica, Y; Pincus, J H; Lewis, M

    1997-12-01

    The skepticism regarding the existence of dissociative identity disorder as well as the abuse that engenders it persists for lack of objective documentation. This is doubly so for the disorder in murderers because of issues of suspected malingering. This article presents objective verification of both dissociative symptoms and severe abuse during childhood in a series of adult murderers with dissociative identity disorder. This study consisted of a review of the clinical records of 11 men and one woman with DSM-IV-defined dissociative identity disorder who had committed murder. Data were gathered from medical, psychiatric, social service, school, military, and prison records and from records of interviews with subjects' family members and others. Handwriting samples were also examined. Data were analyzed qualitatively. Signs and symptoms of dissociative identity disorder in childhood and adulthood were corroborated independently and from several sources in all 12 cases; objective evidence of severe abuse was obtained in 11 cases. The subjects had amnesia for most of the abuse and underreported it. Marked changes in writing style and/or signatures were documented in 10 cases. This study establishes, once and for all, the linkage between early severe abuse and dissociative identity disorder. Further, the data demonstrate that the disorder can be distinguished from malingering and from other disorders. The study shows that it is possible, with great effort, to obtain objective evidence of both the symptoms of dissociative identity disorder and the abuse that engenders it.

  18. Experimental study of improvement of exchanged power in gases by catalytic dissociation: ammonia (1961); Etude experimentale de l'amelioration des echanges de chaleur avec les gaz par dissociation catalytique: ammoniac (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Perroud, P [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires; De La Harpe, A [Centre National de la Recherche Scientifique(CNRS), 75 - Paris (France)

    1961-07-01

    Rates of ammonia dissociation and resulting coefficients of improvement of exchanged power have been measured in an annular channel under following conditions: mean wall temperature until 1500 deg. C (tungsten rod, diameter 3 mm), mass velocity until 11 g/cm{sup 2}.s and absolute pressure between 1.5 and 7 kg/cm{sup 2}. Rate of dissociation is mainly function of wall temperature and total mass flow rate of ammonia; it depends little on entrance gas temperature and is practically independent of pressure. Apparent coefficients of improvement of exchanged power under above conditions (including radiation) have reached 1.8; this maximum was obtained for a mean wall temperature of 1250 deg. C. These coefficients decrease when Reynolds number increases. Finally, a theoretical analysis of the phenomenon is given as well as possibilities of application. (authors) [French] Les taux de dissociation d'ammoniac et les coefficients d'amelioration de puissance echangee resultants ont ete mesures en espace annulaire dans les conditions suivantes: temperature moyenne de paroi jusqu'a 1500 deg. C (barreau de tungstene de diametre 3 mm), vitesse massique jusqu'a 11 g/cm{sup 2}.s et pression absolue comprise entre 1,5 et 7 kg/cm{sup 2}. Le taux de dissociation est surtout fonction de la temperature de paroi et du debit en masse total d'ammoniac; il depend peu de la temperature d'entree du gaz et est pratiquement independant de la pression. Les coefficients d'amelioration apparents de la puissance echangee dans les conditions d'experience (rayonnement compris) ont atteint 1,8. Ce maximum observe se place vers une temperature moyenne de la paroi de 1250 deg. C. Ces coefficients decroissent quand le nombre de Reynolds de l'ecoulement croit. Finalement, une analyse theorique du phenomene est donnee ainsi que les perspectives d'applications. (auteurs)

  19. An alternative approach to treating lateral epicondylitis. A randomized, placebo-controlled, double-blinded study

    NARCIS (Netherlands)

    Nourbakhsh, Mohammad Reza; Fearon, Frank J.

    Objective: To investigate the effect of noxious level electrical stimulation on pain, grip strength and functional abilities in subjects with chronic lateral epicondylitis. Design: Randomized, placebo-control, double-blinded study. Setting: Physical Therapy Department, North Georgia College and

  20. Study of the Dissociative Processes in O{sub 2} Discharges. Development of an Atomic Oxygen Beam Source; Etude de la dissociation de O{sub 2} dans les decharges d'oxygene. Application a la realisation de sources d'atomes

    Energy Technology Data Exchange (ETDEWEB)

    Pagnon, Daniel

    1992-09-24

    The first part of this work is devoted to the study of dissociative processes in an oxygen glow discharge at low pressure (0,1-5 Torr, 1-80 mA). The kinetics of oxygen atoms has been determined supported by the measurements of atomic concentrations by VUV absorption spectroscopy and actinometry. The reaction coefficients for dissociative excitation and direct excitation of oxygen atoms have been calculated using the cross sections of the literature and a previously calculated EEDF. It has been demonstrated that dissociative excitation is negligible in respect with direct excitation for dissociation rates smaller than 2,5 %. An upper limit of 20 % for dissociative rates is observed. This limit has been explained by the increase of the atomic recombination at the discharge wall with increasing wall temperature. Using all these results, we have designed and optimized a source of oxygen atoms which has then been adapted on a MBE device. The spatial distribution of the atomic density has been measured in molecular jet by laser induced fluorescence (LIF) and Resonant Multi-Photon Ionization (RMPI). A stimulated emission has been evidenced and the coefficient for this process evaluated. A model for the effusion of atoms has been developed from which the flow of atoms on the sample can be predicted. This source has already been used in industrial MBE devices for in-situ oxidation of copper films, superconductors, and substrates for VLSI high speed applications. The methodology of this work and the diagnostics developed can be applied to other kinds of discharges, of other molecular gases, to design sources of atoms for the treatment of large area samples. (author) [French] Ce travail debute par l'etude de la dissociation dans une decharge luminescente d'oxygene a basse pression (0,1-5 torr, 1-80 ma). La cinetique des atomes d'oxygene a ete etablie a partir de la mesure des concentrations atomiques par spectroscopie d'absorption vuv et par actinometrie. Les coefficients de

  1. A fundamental study on sodium-water reaction in the double-pool-type LMFBR

    International Nuclear Information System (INIS)

    Yoshida, Kazuo; Akimoto, Tokuzo

    1987-01-01

    In order to evaluate the pressure rise by large sodium-water reaction in the Double-Pool LMFBR, basic tests on pressure wave celerity in rectangular tube are carried out. The initial spike pressure in rectangular-shelled steam generator of the Double Pool reactor, strongly depends on pressure wave celerity. In this study, celerity was measured as a function of pressure wave rising time and pulse height, and influence of water around the test section on celerity was investigated. (author)

  2. Muon background studies for shallow depth Double - Chooz near detector

    Energy Technology Data Exchange (ETDEWEB)

    Gómez, H. [Laboratoire Astroparticule et Cosmologie (APC) - Université Paris 7. Paris (France)

    2015-08-17

    Muon events are one of the main concerns regarding background in neutrino experiments. The placement of experimental set-ups in deep underground facilities reduce considerably their impact on the research of the expected signals. But in the cases where the detector is installed on surface or at shallow depth, muon flux remains high, being necessary their precise identification for further rejection. Total flux, mean energy or angular distributions are some of the parameters that can help to characterize the muons. Empirically, the muon rate can be measured in an experiment by a number of methods. Nevertheless, the capability to determine the muons angular distribution strongly depends on the detector features, while the measurement of the muon energy is quite difficult. Also considering that on-site measurements can not be extrapolated to other sites due to the difference on the overburden and its profile, it is necessary to find an adequate solution to perform the muon characterization. The method described in this work to obtain the main features of the muons reaching the experimental set-up, is based on the muon transport simulation by the MUSIC software, combined with a dedicated sampling algorithm for shallow depth installations based on a modified Gaisser parametrization. This method provides all the required information about the muons for any shallow depth installation if the corresponding overburden profile is implemented. In this work, the method has been applied for the recently commissioned Double - Chooz near detector, which will allow the cross-check between the simulation and the experimental data, as it has been done for the far detector.

  3. Muon background studies for shallow depth Double - Chooz near detector

    International Nuclear Information System (INIS)

    Gómez, H.

    2015-01-01

    Muon events are one of the main concerns regarding background in neutrino experiments. The placement of experimental set-ups in deep underground facilities reduce considerably their impact on the research of the expected signals. But in the cases where the detector is installed on surface or at shallow depth, muon flux remains high, being necessary their precise identification for further rejection. Total flux, mean energy or angular distributions are some of the parameters that can help to characterize the muons. Empirically, the muon rate can be measured in an experiment by a number of methods. Nevertheless, the capability to determine the muons angular distribution strongly depends on the detector features, while the measurement of the muon energy is quite difficult. Also considering that on-site measurements can not be extrapolated to other sites due to the difference on the overburden and its profile, it is necessary to find an adequate solution to perform the muon characterization. The method described in this work to obtain the main features of the muons reaching the experimental set-up, is based on the muon transport simulation by the MUSIC software, combined with a dedicated sampling algorithm for shallow depth installations based on a modified Gaisser parametrization. This method provides all the required information about the muons for any shallow depth installation if the corresponding overburden profile is implemented. In this work, the method has been applied for the recently commissioned Double - Chooz near detector, which will allow the cross-check between the simulation and the experimental data, as it has been done for the far detector

  4. H2 EJECTION FROM POLYCYCLIC AROMATIC HYDROCARBONS: INFRARED MULTIPHOTON DISSOCIATION STUDY OF PROTONATED ACENAPHTHENE AND 9,10-DIHYDROPHENANTHRENE

    International Nuclear Information System (INIS)

    Szczepanski, Jan; Vala, Martin T.; Oomens, Jos; Steill, Jeffrey D.

    2011-01-01

    The infrared multiple-photon dissociation (IRMPD) spectra of protonated acenaphthene ([ACN+H] + ) and 9,10-dihydrophenanthrene ([DHP+H] + ) have been recorded using an infrared free electron laser after the compounds were protonated by electrospray ionization and trapped in a Fourier transform ion cyclotron mass spectrometer. In both compounds, the loss of two mass units is predominant. Density functional calculations (B3LYP/6-311++G(d,p)) of the infrared spectra of all possible protonated isomers of each species showed that the observed IRMPD spectra are best fit to the isomer with the largest proton affinity and lowest relative electronic energy. Potential energy surfaces of the most stable isomers of [ACN+H] + and [DHP+H] + have been calculated for H and H 2 loss. The lowest energy barriers are for loss of H 2 , with predicted energies 4.28 and 4.15 eV, respectively. After H 2 ejection, the adjacent aliphatic hydrogens migrate to the bare ejection site and stabilize the remaining fragment. Single H loss may occur from [ACN+H] + but the energy required is higher. No single H loss is predicted from [DHP+H] + , only H migration around the carbon skeleton. The vibrational bands in the parent closed-shell protonated polycyclic aromatic hydrocarbons are compared to bands observed from the interstellar medium.

  5. Dissociation and Alterations in Brain Function and Structure: Implications for Borderline Personality Disorder.

    Science.gov (United States)

    Krause-Utz, Annegret; Frost, Rachel; Winter, Dorina; Elzinga, Bernet M

    2017-01-01

    Dissociation involves disruptions of usually integrated functions of consciousness, perception, memory, identity, and affect (e.g., depersonalization, derealization, numbing, amnesia, and analgesia). While the precise neurobiological underpinnings of dissociation remain elusive, neuroimaging studies in disorders, characterized by high dissociation (e.g., depersonalization/derealization disorder (DDD), dissociative identity disorder (DID), dissociative subtype of posttraumatic stress disorder (D-PTSD)), have provided valuable insight into brain alterations possibly underlying dissociation. Neuroimaging studies in borderline personality disorder (BPD), investigating links between altered brain function/structure and dissociation, are still relatively rare. In this article, we provide an overview of neurobiological models of dissociation, primarily based on research in DDD, DID, and D-PTSD. Based on this background, we review recent neuroimaging studies on associations between dissociation and altered brain function and structure in BPD. These studies are discussed in the context of earlier findings regarding methodological differences and limitations and concerning possible implications for future research and the clinical setting.

  6. [Characteristics of Bacillus cereus dissociants].

    Science.gov (United States)

    Doroshenko, E V; Loĭko, N G; Il'inskaia, O N; Kolpakov, A I; Gornova, I B; Klimanova, E V; El'-Registan, G I

    2001-01-01

    The autoregulation of the phenotypic (populational) variability of the Bacillus cereus strain 504 was studied. The isolated colonial morphotypes of this bacterium were found to differ in their growth characteristics and the synthesis of extracellular proteases. The phenotypic variabilities of vegetative proliferating cells and those germinated from endospores and cystlike refractory cells were different. Bacterial variants also differed in the production of the d1 and d2 factors (the autoinducers of dormancy and autolysis, respectively) and sensitivity to them. The possible role of these factors in the dissociation of microorganisms is discussed.

  7. The responses of dissociative patients on the thematic apperception test.

    Science.gov (United States)

    Pica, M; Beere, D; Lovinger, S; Dush, D

    2001-07-01

    This study compared the responses of dissociative inpatients and general inpatient psychiatric controls on the Thematic Apperception Test (TAT; Murray, 1943). We found the stories of dissociative participants to be characterized by a greater interpersonal distance and more trauma and dissociation responses than those of the controls. No significant differences were found regarding total number of emotional references, although references to positive emotions were almost nonexistent for the dissociative group. A post hoc analysis of the data found the testing behaviors of dissociative participants to be characterized by switching, trance states, intrainterview amnesias, and affectively loaded card rejections. Questions were raised regarding the relevancy of the findings to clinical practice and how they might explain some of the controversies surrounding the diagnosis of dissociative identity disorder (DID). Copyright 2001 John Wiley & Sons, Inc.

  8. Electromagnetic dissociation of relativistic [sup 28]Si by nucleon emission

    Energy Technology Data Exchange (ETDEWEB)

    Sonnadara, U.J.

    1992-12-01

    A detailed study of the electromagnetic dissociation of [sup 28]Si by nucleon emission at E[sub lab]/A = 14.6 (GeV/nucleon was carried out with [sup 28]Si beams interacting on [sup 208]Pb). [sup 120]Sn. [sup 64]C targets. The measurements apparatus consists of detectors in the target area which measure the energy and charged multiplicity, and a forward spectrometer which measures the position, momentum and energy of the reaction fragments. The exclusive electromagnetic dissociation cross sections for decay channels having multiple nucleons in the final state have been measured which enables the selection of events produced in pure electromagnetic interactions. The measured cross sections agree well with previous measurements obtained for the removal of a few nucleons as well as with measurements on total charge removal cross sections from other experiments. The dependence of the integrated cross sections on the target charge Z[sub T] and the target mass AT confirms that for higher Z targets the excitation is largely electromagnetic. Direct measurements of the excitation energy for the electromagnetic dissociation of [sup 28]Si [yields] p+[sup 27]Al and [sup 28]Si [yields] n+[sup 27]Si have been obtained through a calculation of the invariant mass in kinematically, reconstructed events. The excitation energy spectrum for all targets peak near the isovector giant dipole resonance in [sup 28]Si. These distributions are well reproduced by combining the photon spectrum calculated using the Weizsaecker-Williams approximation with the experimental data on the photonuclear [sup 28]Si([sub [gamma],p])[sup 27]Al and [sup 28]Si([sub [gamma],n])[sup 27]Si. The possibilities of observing double giant dipole resonance excitations in [sup 28]Si have been investigated with cross section measurements as well as with excitation energy reconstruction.

  9. Experimental study of heat transfer to the N2O4 dissociating coolant in the circular tube with variable heat load on the wall

    International Nuclear Information System (INIS)

    Golovnya, V.N.; Kolykhan, L.I.

    1983-01-01

    The results of the experimental study of heat transfer to N 2 O 4 dissociating coolant with a sinusoidal law of heat flux density variation by length are presented. The heat transfer process has been studied at subcritical and supercritical parameters and different substance aggregation states. Maximum error of heat transfer coefficient determination don't exceed 15%. The esimation of the effect of variable heat load on heat transfer has been condUcted by comparison of experimental data on the Nusselt number change along the tube length with that calculated using conventional relations for the conditions of uniform heat release. It is shown that heat transfer is enhanced in the region of heat load qsub(c) growth while its intensity is decreased in the region of heat flux reduction. The quantitative effect of qsub(c) variation on heat transfer can be regarded for by the method of superpositions

  10. Dissociation of Vertical Semiconductor Diatomic Artificial Molecules

    International Nuclear Information System (INIS)

    Pi, M.; Emperador, A.; Barranco, M.; Garcias, F.; Muraki, K.; Tarucha, S.; Austing, D. G.

    2001-01-01

    We investigate the dissociation of few-electron circular vertical semiconductor double quantum dot artificial molecules at 0T as a function of interdot distance. A slight mismatch introduced in the fabrication of the artificial molecules from nominally identical constituent quantum wells induces localization by offsetting the energy levels in the quantum dots by up to 2meV, and this plays a crucial role in the appearance of the addition energy spectra as a function of coupling strength particularly in the weak coupling limit

  11. Thought beyond language: neural dissociation of algebra and natural language.

    Science.gov (United States)

    Monti, Martin M; Parsons, Lawrence M; Osherson, Daniel N

    2012-08-01

    A central question in cognitive science is whether natural language provides combinatorial operations that are essential to diverse domains of thought. In the study reported here, we addressed this issue by examining the role of linguistic mechanisms in forging the hierarchical structures of algebra. In a 3-T functional MRI experiment, we showed that processing of the syntax-like operations of algebra does not rely on the neural mechanisms of natural language. Our findings indicate that processing the syntax of language elicits the known substrate of linguistic competence, whereas algebraic operations recruit bilateral parietal brain regions previously implicated in the representation of magnitude. This double dissociation argues against the view that language provides the structure of thought across all cognitive domains.

  12. Dissociation of Procedural and Working Memory in Pigeons (Columba livia

    Directory of Open Access Journals (Sweden)

    Walter T. Herbranson

    2016-07-01

    Full Text Available A new method was developed to concurrently investigate procedural memory and working memory in pigeons. Pigeons performed a sequence of keypecks across 3 response keys in a serial response task, with periodic choice probes for the location of a recently produced response. Procedural memory was operationally defined as decreasing response times to predictable cues in the sequence. Working memory was reflected by accurate responses to the choice probes. Changing the sequence of required keypecks to a random sequence interfered with procedural memory in the form of slowed response times, but did not prevent pigeons from effectively using working memory to remember specific cue locations. Conversely, changing exposure duration of to a cue location influenced working memory but had no effect on procedural memory. Double dissociations such as this have supported the multiple systems approach to the study of memory in cognitive psychology and neuroscience, and they encourage a similar approach in comparative psychology.

  13. Childhood maltreatment and intimate partner violence in dissociative disorder patients.

    Science.gov (United States)

    Webermann, Aliya R; Brand, Bethany L; Chasson, Gregory S

    2014-01-01

    Childhood maltreatment (CM) is a risk factor for subsequent intimate partner violence (IPV) in adulthood, with high rates of retrospectively reported CM among IPV victims and perpetrators. A theorized mechanism of the link between CM and IPV is dissociation. Dissociation may allow perpetrators of violence to remain emotionally distant from their behavior and minimize empathy toward those they victimize, enabling them to commit acts of violence similar to their own experiences. Indeed, elevated rates of dissociation and dissociative disorders (DD) have been found among IPV survivors and perpetrators. In addition, in pilot studies, DD clinicians have reported high levels of violent behavior among DD patients. The present study investigates IPV among DD patients with Dissociative Identity Disorder and Dissociative Disorder Not Otherwise Specified, a group with CM rates of 80-95% and severe dissociative symptoms. DD clinicians reported on rates of CM and IPV among 275 DD patients in outpatient treatment. DD patients also completed a self-report measure of dissociation. Analyses assessed the associations between CM typologies and IPV, as well as trait dissociation and IPV. Physical and emotional child abuse were associated with physical IPV, and childhood witnessing of domestic violence (DV) and childhood neglect were associated with emotional IPV. The present study is the first to provide empirical support for a possible CM to adult IPV developmental trajectory among DD patients. Future research is needed to better understand the link between CM and IPV among those with trauma and DD.

  14. Frontal and occipital perfusion changes in dissociative identity disorder.

    Science.gov (United States)

    Sar, Vedat; Unal, Seher N; Ozturk, Erdinc

    2007-12-15

    The aim of the study was to investigate if there were any characteristics of regional cerebral blood flow (rCBF) in dissociative identity disorder. Twenty-one drug-free patients with dissociative identity disorder and nine healthy volunteers participated in the study. In addition to a clinical evaluation, dissociative psychopathology was assessed using the Structured Clinical Interview for DSM-IV Dissociative Disorders, the Dissociative Experiences Scale and the Clinician-Administered Dissociative States Scale. A semi-structured interview for borderline personality disorder, the Hamilton Depression Rating Scale, and the Childhood Trauma Questionnaire were also administered to all patients. Normal controls had to be without a history of childhood trauma and without any depressive or dissociative disorder. Regional cerebral blood flow (rCBF) was studied with single photon emission computed tomography (SPECT) with Tc99m-hexamethylpropylenamine (HMPAO) as a tracer. Compared with findings in the control group, the rCBF ratio was decreased among patients with dissociative identity disorder in the orbitofrontal region bilaterally. It was increased in median and superior frontal regions and occipital regions bilaterally. There was no significant correlation between rCBF ratios of the regions of interest and any of the psychopathology scale scores. An explanation for the neurophysiology of dissociative psychopathology has to invoke a comprehensive model of interaction between anterior and posterior brain regions.

  15. Childhood maltreatment and intimate partner violence in dissociative disorder patients

    Directory of Open Access Journals (Sweden)

    Aliya R. Webermann

    2014-09-01

    Full Text Available Background: Childhood maltreatment (CM is a risk factor for subsequent intimate partner violence (IPV in adulthood, with high rates of retrospectively reported CM among IPV victims and perpetrators. A theorized mechanism of the link between CM and IPV is dissociation. Dissociation may allow perpetrators of violence to remain emotionally distant from their behavior and minimize empathy toward those they victimize, enabling them to commit acts of violence similar to their own experiences. Indeed, elevated rates of dissociation and dissociative disorders (DD have been found among IPV survivors and perpetrators. In addition, in pilot studies, DD clinicians have reported high levels of violent behavior among DD patients. Objective: The present study investigates IPV among DD patients with Dissociative Identity Disorder and Dissociative Disorder Not Otherwise Specified, a group with CM rates of 80–95% and severe dissociative symptoms. Methods: DD clinicians reported on rates of CM and IPV among 275 DD patients in outpatient treatment. DD patients also completed a self-report measure of dissociation. Analyses assessed the associations between CM typologies and IPV, as well as trait dissociation and IPV. Results: Physical and emotional child abuse were associated with physical IPV, and childhood witnessing of domestic violence (DV and childhood neglect were associated with emotional IPV. Conclusions: The present study is the first to provide empirical support for a possible CM to adult IPV developmental trajectory among DD patients. Future research is needed to better understand the link between CM and IPV among those with trauma and DD.

  16. Dissociating Memory Networks in Early Alzheimer’s Disease and Frontotemporal Lobar Degeneration - A Combined Study of Hypometabolism and Atrophy

    Science.gov (United States)

    Frisch, Stefan; Dukart, Juergen; Vogt, Barbara; Horstmann, Annette; Becker, Georg; Villringer, Arno; Barthel, Henryk; Sabri, Osama; Müller, Karsten; Schroeter, Matthias L.

    2013-01-01

    Introduction We aimed at dissociating the neural correlates of memory disorders in Alzheimer’s disease (AD) and frontotemporal lobar degeneration (FTLD). Methods We included patients with AD (n = 19, 11 female, mean age 61 years) and FTLD (n = 11, 5 female, mean age 61 years) in early stages of their diseases. Memory performance was assessed by means of verbal and visual memory subtests from the Wechsler Memory Scale (WMS-R), including forgetting rates. Brain glucose utilization was measured by [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) and brain atrophy by voxel-based morphometry (VBM) of T1-weighted magnetic resonance imaging (MRI) scans. Using a whole brain approach, correlations between test performance and imaging data were computed separately in each dementia group, including a group of control subjects (n = 13, 6 female, mean age 54 years) in both analyses. The three groups did not differ with respect to education and gender. Results Patients in both dementia groups generally performed worse than controls, but AD and FTLD patients did not differ from each other in any of the test parameters. However, memory performance was associated with different brain regions in the patient groups, with respect to both hypometabolism and atrophy: Whereas in AD patients test performance was mainly correlated with changes in the parieto-mesial cortex, performance in FTLD patients was correlated with changes in frontal cortical as well as subcortical regions. There were practically no overlapping regions associated with memory disorders in AD and FTLD as revealed by a conjunction analysis. Conclusion Memory test performance may not distinguish between both dementia syndromes. In clinical practice, this may lead to misdiagnosis of FTLD patients with poor memory performance. Nevertheless, memory problems are associated with almost completely different neural correlates in both dementia syndromes. Obviously, memory functions are carried out by

  17. Photo-dissociation of hydrogen passivated dopants in gallium arsenide

    International Nuclear Information System (INIS)

    Tong, L.; Larsson, J.A.; Nolan, M.; Murtagh, M.; Greer, J.C.; Barbe, M.; Bailly, F.; Chevallier, J.; Silvestre, F.S.; Loridant-Bernard, D.; Constant, E.; Constant, F.M.

    2002-01-01

    A theoretical and experimental study of the photo-dissociation mechanisms of hydrogen passivated n- and p-type dopants in gallium arsenide is presented. The photo-induced dissociation of the Si Ga -H complex has been observed for relatively low photon energies (3.48 eV), whereas the photo-dissociation of C As -H is not observed for photon energies up to 5.58 eV. This fundamental difference in the photo-dissociation behavior between the two dopants is explained in terms of the localized excitation energies about the Si-H and C-H bonds

  18. Traumatic dissociation as a predictor of posttraumatic stress disorder in South African female rape survivors.

    Science.gov (United States)

    Nöthling, Jani; Lammers, Kees; Martin, Lindi; Seedat, Soraya

    2015-04-01

    Women survivors of rape are at an increased risk for posttraumatic stress disorder (PTSD). Traumatic dissociation has been identified as a precursor of PTSD. This study assessed the predictive potential of traumatic dissociation in PTSD and depression development.The study followed a longitudinal, prospective design. Ninety-seven female rape survivors were recruited from 2 clinics in Cape Town, South Africa. Clinical interviews and symptom status assessments of the participants were completed to measure dissociation, childhood traumas, resilience, depression, and PTSD.Traumatic dissociation was a significant predictor of PTSD and depression. The linear combination of prior dissociation, current dissociation, and resilience significantly explained 20.7% of the variance in PTSD. Dissociation mediated the relationship between resilience and PTSD.As traumatic dissociation significantly predicts PTSD, its early identification and management may reduce the risk of developing PTSD. Interventions focused on promoting resilience may also be successful in reducing the risk of dissociation following rape.

  19. Traumatic Dissociation as a Predictor of Posttraumatic Stress Disorder in South African Female Rape Survivors

    Science.gov (United States)

    Nöthling, Jani; Lammers, Kees; Martin, Lindi; Seedat, Soraya

    2015-01-01

    Abstract Women survivors of rape are at an increased risk for posttraumatic stress disorder (PTSD). Traumatic dissociation has been identified as a precursor of PTSD. This study assessed the predictive potential of traumatic dissociation in PTSD and depression development. The study followed a longitudinal, prospective design. Ninety-seven female rape survivors were recruited from 2 clinics in Cape Town, South Africa. Clinical interviews and symptom status assessments of the participants were completed to measure dissociation, childhood traumas, resilience, depression, and PTSD. Traumatic dissociation was a significant predictor of PTSD and depression. The linear combination of prior dissociation, current dissociation, and resilience significantly explained 20.7% of the variance in PTSD. Dissociation mediated the relationship between resilience and PTSD. As traumatic dissociation significantly predicts PTSD, its early identification and management may reduce the risk of developing PTSD. Interventions focused on promoting resilience may also be successful in reducing the risk of dissociation following rape. PMID:25906104

  20. Dissociative features in posttraumatic stress disorder: A latent profile analysis.

    Science.gov (United States)

    Műllerová, Jana; Hansen, Maj; Contractor, Ateka A; Elhai, Jon D; Armour, Cherie

    2016-09-01

    The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) characterizes the dissociative subtype of posttraumatic stress disorder (PTSD) in terms of the individual meeting the criteria for PTSD and additionally reporting symptoms of depersonalization and/or derealization. The current study aimed to examine whether a dissociative PTSD profile may include alternative features of dissociation and whether it could be differentiated from a nondissociative PTSD profile on certain psychopathologies and demographics. Data from 309 trauma-exposed participants, collected through Amazon Mechanical Turk, were subjected to latent profile analysis. Regression analyses were used to examine the predictors of latent classes. Three discrete profiles named Baseline, PTSD, and Dissociative profile were uncovered. All examined features of dissociation were significantly elevated in the Dissociative profile. Anxiety, male sex, being employed, and having a minority racial background significantly predicted the Dissociative profile relative to the PTSD profile. The study points to the importance of alternative symptoms of dissociation in the dissociative PTSD subtype beyond the symptoms of depersonalization and derealization. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  1. Surface species formed by the adsorption and dissociation of water molecules on Ru(0001) surface containing a small coverage of carbon atoms studied by scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dept of Materials Science and Engineering UCB; Dept of Applied Science and Technology, UCB; Institut de Ciencia de Materials de Barcelona, Barcelona, Spain; Instituto de Ciencia de Materiales de Madrid, Madrid, Spain; Department of Mechanical Engineering, Yale University; Salmeron, Miquel; Shimizu, Tomoko K.; Mugarza, Aitor; Cerda, Jorge I.; Heyde, Markus; Qi, Yabing; Schwarz, Udo D.; Ogletree, D. Frank; Salmeron, Miquel

    2008-04-26

    The adsorption and dissociation of water on a Ru(0001) surface containing a small amount ({le} 3 %) of carbon impurities was studied by scanning tunneling microscopy (STM). Various surface species are formed depending on the temperature. These include molecular H{sub 2}O, H{sub 2}O-C complexes, H, O, OH and CH. Clusters of either pure H{sub 2}O or mixed H{sub 2}O-OH species are also formed. Each of these species produces a characteristic contrast in the STM images and can be identified by experiment and by ab initio total energy calculations coupled with STM image simulations. Manipulation of individual species via excitation of vibrational modes with the tunneling electrons has been used as supporting evidence.

  2. Dissociative multiple ionization of diatomic molecules by extreme-ultraviolet free-electron-laser pulses

    DEFF Research Database (Denmark)

    Madsen, Lars Bojer; Leth, Henriette Astrup

    2011-01-01

    Nuclear dynamics in dissociative multiple ionization processes of diatomic molecules exposed to extreme-ultraviolet free-electron-laser pulses is studied theoretically using the Monte Carlo wave packet approach. By simulated detection of the emitted electrons, the model reduces a full propagation...... of the system to propagations of the nuclear wave packet in one specific electronic charge state at a time. Suggested ionization channels can be examined, and kinetic energy release spectra for the nuclei can be calculated and compared with experiments. Double ionization of O2 is studied as an example, and good...

  3. Childhood emotional abuse, dissociation, and suicidality among patients with drug dependency in Turkey.

    Science.gov (United States)

    Tamar-Gurol, Defne; Sar, Vedat; Karadag, Figen; Evren, Cuneyt; Karagoz, Mustafa

    2008-10-01

    The aim of the present study was to determine the prevalence and correlates of dissociative disorders among patients with drug dependency. The Dissociative Experiences Scale (DES) was used to screen 104 consecutive patients at an addiction treatment center. Thirty-seven patients who had scores >or=30 were compared with 21 patients who scored suicide attempt and/or childhood emotional abuse was significant predictors of a dissociative disorder. The majority (59.3%) of dissociative drug users reported that dissociative experiences had existed prior to substance use. More patients in the dissociative disorder than in the non-dissociative group stopped their treatment prematurely. A considerable proportion of drug users have a dissociative disorder, which may also interfere with treatment process. The relatively young age of this subgroup of patients and frequent reports of childhood emotional abuse underline potential preventive benefits of early intervention among adolescents with developmental trauma history and dissociative psychopathology.

  4. Does phasic trauma treatment make patients with dissociative identity disorder treatment more dissociative?

    Science.gov (United States)

    Brand, Bethany; Loewenstein, Richard J

    2014-01-01

    Proponents of the iatrogenic model of the etiology of dissociative identity disorder (DID) have expressed concern that treatment focused on direct engagement and interaction with dissociated self-states harms DID patients. However, empirical data have shown that this type of DID treatment is beneficial. Analyzing data from the prospective Treatment of Patients With Dissociative Disorders (TOP DD) Study, we test empirically whether DID treatment is associated with clinically adverse manifestations of dissociated self-states: acting so differently that one feels like different people, hearing voices, and dissociative amnesia. We show that, over the course of the study, there were significant decreases in feeling like different people and hearing voices. These results indicate that this form of DID treatment does not lead to symptomatic worsening in these dimensions, as predicted by the iatrogenic model. Indeed, treatment provided by TOP DD therapists reduced, rather than increased, the extent to which patients experienced manifestations of pathological dissociation. Because severe symptomatology and impairment are associated with DID, iatrogenic harm may come from depriving DID patients of treatment that targets DID symptomatology.

  5. Study of photoionization and dissociative photoionization of carbon monoxide from ionization threshold to 38 eV by using synchrotron radiation

    International Nuclear Information System (INIS)

    Zhao, Yujie; Cao, Maoqi; Li, Yuquan; Shan, Xiaobin; Liu, Fuyi; Sheng, Liusi; Li, Li; Liu, Wanfang

    2014-01-01

    Highlights: • The high resolution photoionization spectrum of carbon monoxide has been investigated using tunable synchrotron radiation. • This work has investigated comprehensively almost all kinds of photo excitation processes of CO in wide photon region. • The mechanisms of photoionization and dissociative photoionization of CO have been researched in detail. - Abstract: The vacuum-ultraviolet photoionization and dissociative photoionization of carbon monoxide in a region 14–38 eV have been investigated with time-of-flight (TOF) photoionization mass spectrometry (PIMS) using tunable synchrotron radiation (SR). The adiabatic ionization energy (IE) of carbon monoxide and appearance energies (AE) for its fragment ions in different states are determined by measurements of photoionization efficiency spectra (PIES). Ab initio calculations have been performed to investigate the reaction mechanism of dissociative photoionization of carbon monoxide. On the basis of experimental and predicted theoretical results, the mechanisms of photoionization and dissociative photoionization of molecular CO are discussed, and sixteen dissociative photoionization processes are proposed. The equilibrium geometries and harmonic vibrational frequencies of CO molecule, and its parent cation were calculated by using MP2 (full) method. The differences of configurations between them are also discussed on the basis of theoretical calculations. According to our results, the experimental IE of CO molecule, and dissociation energies (E d ) of possible dissociative channels are in reasonable agreement with the calculated values of the proposed photodissociation channels

  6. Multiphoton dissociation of polyatomic molecules

    International Nuclear Information System (INIS)

    Schulz, P.A.

    1979-10-01

    The dynamics of infrared multiphoton excitation and dissociation of SF 6 was investigated under collision free conditions by a crossed laser-molecular beam method. In order to understand the excitation mechanism and to elucidate the requirements of laser intensity and energy fluence, a series of experiments were carried out to measure the dissociation yield dependences on energy fluence, vibrational temperature of SF 6 , the pulse duration of the CO 2 laser and the frequency in both one and two laser experiments. Translational energy distributions of the SF 5 dissociation product measured by time of flight and angular distributions and the dissociation lifetime of excited SF 6 as inferred from the observation of secondary dissociation of SF 5 into SF 4 and F during the laser pulse suggest that the dynamics of dissociation of excited molecules is dominated by complete energy randomization and rapid intramolecular energy transfer on a nanosecond timescale, and can be adequately described by RRKM theory. An improved phenomenological model including the initial intensity dependent excitation, a rate equation describing the absorption and stimulated emission of single photons, and the unimolecular dissociation of excited molecules is constructed based on available experimental results. The model shows that the energy fluence of the laser determines the excitation of molecules in the quasi-continuum and the excess energy with which molecules dissociate after the laser pulse. The role played by the laser intensity in multiphoton dissociation is more significant than just that of overcoming the intensity dependent absorption in the lowest levels. 63 references

  7. Predictors of trait dissociation and peritraumatic dissociation induced via cold pressor.

    Science.gov (United States)

    Gómez-Pérez, Lydia; López-Martínez, Alicia Eva; Asmundson, Gordon John Glenn

    2013-11-30

    Understanding which factors predict individual dissociative response during stressful situations is important to clarify the nature of dissociation and the mechanisms associated to its use as a coping strategy. The present study examined (1) whether experiential avoidance (EA), anxiety sensitivity (AS), depressive symptoms, and state anxiety concurrently predicted trait dissociation (TD)-absorption, amnesia, depersonalization, and total TD scores-and laboratory induced dissociation (LID); and (2) whether TD and catastrophizing predicted LID. We also examined whether catastrophizing mediated the relationships between both AS and depressive symptoms and LID. A total of 101 female undergraduate students participated in a cold pressor task, which significantly induced dissociation. Results of hierarchical regression analyses showed that AS at Time 1 (9 months before the experimental session), as well as depressive symptoms and catastrophizing at the time of the experiment (Time 2), predicted LID at Time 2. Depressive symptoms at Time 2 predicted total TD, absorption, and amnesia scores. AS at Time 1 and depressive symptoms at Time 2 predicted depersonalization. AS, depressive symptoms, and catastrophizing seem to facilitate the use of dissociative strategies by healthy individuals, even in response to non-traumatic but discomforting stress. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  8. A COMPARATIVE STUDY OF SINGLE VERSUS DOUBLE LAYER CLOSURE ON LOWER SEGMENT CAESAREAN SCAR

    Directory of Open Access Journals (Sweden)

    Kirtirekha Mohapatra

    2016-10-01

    Full Text Available BACKGROUND There are few issues in modern obstetrics that have been as controversial as management of a woman with a prior caesarean delivery. Hence, it is required to have evidence based correct practice of this surgical procedure. Healing of the uterine incision and the strength of the scar should be the most important consideration. The aim of the study is to compare the effect of technique of uterine closure (Single Layer vs. Double Layer on subsequent pregnancies and to find out, which technique has a better maternal and neonatal outcome by strengthening the scar. MATERIALS AND METHODS 500 cases of previous caesarean section pregnancies were taken, 250 from single layer closure group and 250 from double layer closure group. The mode of delivery during present pregnancy was noted. Integrity of scar, thickness of scar, presence of adhesion were documented. The neonates were observed. Results were compared so as to draw an inference about the better method. RESULTS Mean age between the two groups were similar. Majority did not have history of premature rupture of membrane during previous pregnancy. Postoperative complications were more when double layer closure of uterine scar was done in index surgery. Interpregnancy gap of <3 years was more commonly present in double layer closure group (52.8% in double layer versus 34.8% in single layer. Single layer had more scar tenderness (21.2%, thinned out scars (34.6%, incomplete ruptures (7.1% and complete ruptures (2.8% than double layer closure group. Neonatal outcomes were not statistically different in both the groups. CONCLUSION Double layer uterine closure seems to have better impact on scar integrity as compared to single layer uterine closure.

  9. Nuclear responses for neutrinos and neutrino studies by double ...

    Indian Academy of Sciences (India)

    0.03 eV and real-time exclusive studies of the low energy solarν's by inverse β ... Therefore the intensity ratio of the pp ν and the Be ν is independent of ... The 0νββ events are identified by setting the appropriate energy window and the prompt.

  10. Albinism in Botswana Junior Secondary Schools: A Double Case Study

    Science.gov (United States)

    Dart, Gareth; Nkanotsang, Tiroyaone; Chizwe, Ose; Kowa, Lily

    2010-01-01

    Pupils with albinism potentially face a number of challenges in accessing quality education in schools in Botswana. Physical issues such as poor eyesight related to the condition and the problems of sensitive skin in such a dry and warm climate are both contributing factors to making learning problematic for some pupils. This study by Gareth Dart…

  11. Studies of interaction between two alkaloids and double helix DNA

    International Nuclear Information System (INIS)

    Sun, Yantao; Peng, Tingting; Zhao, Lei; Jiang, Dayu; Cui, Yuncheng

    2014-01-01

    This article presents the study on the interaction of two alkaloids (matrine and evodiamine) and hs-DNA by absorption, fluorescence, circular dichroism (CD), DNA melting and viscosity experiments. The spectroscopic studies suggested that two alkaloids can bind to DNA through an intercalative mode. The viscosity measurement and thermal denaturation also indicated that two alkaloids can intercalate to DNA. The binding constants (K A ) and the number of binding sites (n) were determined. At the same time, some significant thermodynamic parameters of the binding of the alkaloids to DNA were obtained. Competitive binding studies revealed that alkaloids had an effect on ethidium bromide (EB) bound DNA. In addition, it was also proved that the fluorescence quenching was influenced by ionic strength. - Highlights: • Interaction between two alkaloids and DNA is studied by spectral methods. • The binding constant and the binding sites between two alkaloids and DNA are obtained. • There are a classical intercalative mode between alkaloids and DNA. • The binding of matrine with DNA is weaker than that of evodiamine. • It is important for us to understand the alkaloids–DNA interactions at a molecular level

  12. Studies of double-sided silicon microstrip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, S.C. [New Mexico Univ., Albuquerque, NM (United States). Center for Particle Phys.; Bruner, N.L. [New Mexico Univ., Albuquerque, NM (United States). Center for Particle Phys.; Frautschi, M.A. [New Mexico Univ., Albuquerque, NM (United States). Center for Particle Phys.; Hoeferkamp, M.R. [New Mexico Univ., Albuquerque, NM (United States). Center for Particle Phys.; Patton, A. [New Mexico Univ., Albuquerque, NM (United States). Center for Particle Phys.

    1996-12-01

    The electrical characteristics of detectors manufactured by SINTEF/SI with a variety of geometrical and processing options have been investigated. The detectors` leakage current, depletion voltage, bias resistance, interstrip and coupling capacitance, and coupling capacitor breakdown voltage were studied. (orig.).

  13. Studies of double-sided silicon microstrip detectors

    International Nuclear Information System (INIS)

    Seidel, S.C.; Bruner, N.L.; Frautschi, M.A.; Hoeferkamp, M.R.; Patton, A.

    1996-01-01

    The electrical characteristics of detectors manufactured by SINTEF/SI with a variety of geometrical and processing options have been investigated. The detectors' leakage current, depletion voltage, bias resistance, interstrip and coupling capacitance, and coupling capacitor breakdown voltage were studied. (orig.)

  14. Clinical effects of buspirone in social phobia : A double-blind placebo-controlled study

    NARCIS (Netherlands)

    denBoer, JA; Westenberg, HGM; Pian, KLH

    Background: The results of open pilot studies suggest that the serotonin-1A (5-HT1A) receptor agonist buspirone might be effective in social phobia. Method: In the present study, the efficacy of buspirone was investigated in patients with social phobia using a 12-week double-blind placebo-controlled

  15. ADHD and EEG-neurofeedback: a double-blind randomized placebo-controlled feasibility study

    NARCIS (Netherlands)

    Lansbergen, M.M.; Dongen-Boomsma, M. van; Buitelaar, J.K.; Slaats-Willemse, D.I.E.

    2011-01-01

    Electroencephalography (EEG)-neurofeedback has been shown to offer therapeutic benefits to patients with attention-deficit/hyperactivity disorder (ADHD) in several, mostly uncontrolled studies. This pilot study is designed to test the feasibility and safety of using a double-blind placebo

  16. Dissociative State and Competence

    Directory of Open Access Journals (Sweden)

    Yu-Ju Lin

    2007-10-01

    Full Text Available This report presents the results of forensic evaluation of the civil competence of a case of alleged dissociative identity disorder (DID and discusses whether such dissociative states substantially jeopardize civil competence. A 40-year-old woman claimed that she had had many personalities since her college days. From the age of 37 to 40, she shopped excessively, which left her with millions of dollars of debt. She ascribed her shopping to a certain identity state, over which she had no control. (In this article, we use the term identity state to replace personality as an objective description of a mental state. She thus raised the petition of civil incompetence. During the forensic evaluation, it was found that the identity states were relatively stable and mutually aware of each other. The switch into another identity state was sometimes under voluntary control. The subject showed consistency and continuity in behavioral patterns across the different identity states, and no matter which identity state she was in, there was no evidence of impairment in her factual knowledge of social situations and her capacity for managing personal affairs. We hence concluded that she was civilly competent despite the claimed DID. Considering that the existence and diagnosis of DID are still under dispute and a diagnosis of DID alone is not sufficient to interdict a person's civil right, important clinical and forensic issues remain to be answered.

  17. A study of Double Pomeron Exchange in ALICE

    CERN Document Server

    Kirk, A.

    1998-01-01

    The non-Abelian nature of QCD suggests that particles that have a gluon constituent, such as glueballs or hybrids, should exist. Experiments WA76, WA91 and WA102 have performed a dedicated search for these states in central production using the CERN Omega Spectrometer. New results from central production show that there is a kinematical filter which can select out glueball candidates from known qqbar states. A further study of this at high energies is essential in order to get information on the M(X0) > 2 GeV region. This paper describes how this could be done using the the ALICE detector at the LHC.

  18. Hyperglycemia associated dissociative fugue (organic dissociative disorder) in an elderly.

    Science.gov (United States)

    Ram, Dushad; Ashoka, H G; Gowdappa, Basavnna

    2015-01-01

    Inadequate glycemic control in patients with diabetes is known to be associated with psychiatric disorders such as depression, anxiety disorder, and cognitive impairment. However, dissociative syndrome has not been reported so far. Here we are reporting a case of repeated dissociative fugue associated with hyperglycemia, in an elderly with type II diabetes. Possible neurobiological mechanism has been discussed.

  19. Hyperglycemia associated dissociative fugue (organic dissociative disorder) in an elderly

    OpenAIRE

    Ram, Dushad; Ashoka, H. G; Gowdappa, Basavnna

    2015-01-01

    Inadequate glycemic control in patients with diabetes is known to be associated with psychiatric disorders such as depression, anxiety disorder, and cognitive impairment. However, dissociative syndrome has not been reported so far. Here we are reporting a case of repeated dissociative fugue associated with hyperglycemia, in an elderly with type II diabetes. Possible neurobiological mechanism has been discussed.

  20. Hyperglycemia associated dissociative fugue (organic dissociative disorder in an elderly

    Directory of Open Access Journals (Sweden)

    Dushad Ram

    2015-01-01

    Full Text Available Inadequate glycemic control in patients with diabetes is known to be associated with psychiatric disorders such as depression, anxiety disorder, and cognitive impairment. However, dissociative syndrome has not been reported so far. Here we are reporting a case of repeated dissociative fugue associated with hyperglycemia, in an elderly with type II diabetes. Possible neurobiological mechanism has been discussed.

  1. Dissociative style and individual differences in verbal working memory span.

    NARCIS (Netherlands)

    de Ruiter, M.B.; Phaf, R.H.; Elzinga, B.M.; van Dyck, R.

    2004-01-01

    Dissociative style is mostly studied as a risk factor for dissociative pathology, but it may also reflect a fundamental characteristic of healthy information processing. Due to the close link between attention and working memory and the previous finding of enhanced attentional abilities with a high

  2. Self-Destructive Behavior in People with Dissociative Disorders.

    Science.gov (United States)

    Saxe, Glenn N.; Chawla, Neharika; Van der Kolk, Bessel

    2002-01-01

    Study assesses self-destructive behavior in a group of inpatients who have dissociative disorders compared to those who report few dissociative symptoms. Results reveal that these patients more frequently engage in self-destructive behaviors, use more methods of self-injury, and begin to injure themselves at an earlier age then patients who do not…

  3. Studying thermal dehydration of double nickel alkali metal pyrophosphates

    International Nuclear Information System (INIS)

    Bykanova, T.A.; Lavrov, A.V.; AN SSSR, Moscow. Inst. Obshchej i Neorganicheskoj Khimii)

    1978-01-01

    The methods of thermogravimetry, paper chromatography, infrared spectroscopy and X-ray phase analysis were used in studying the process of thermal dehydration of pyrophosphates of the M 2 Ni 3 (P 2 O 7 ) 2 xnH 2 O type (where n=6, 10; M=Na, K, Rb, Cs, NH 4 ). The dehydration of Cs 2 Ni 3 (P 2 O 7 ) 2 x10H 2 O proceeds in a single stage (endothermal effect at 210 deg C). The exothermal effects at 730 and 690 deg C correspond to the crystallization of the amorphous dehydration products. It has been established that binary pyrophosphates of nickel with alkali metals decompose when heated into Ni 3 (PO 4 ) 2 +MPO 4

  4. The Dissociative Subtype of Posttraumatic Stress Disorder (PTSD) Among Adolescents: Co-Occurring PTSD, Depersonalization/Derealization, and Other Dissociation Symptoms.

    Science.gov (United States)

    Choi, Kristen R; Seng, Julia S; Briggs, Ernestine C; Munro-Kramer, Michelle L; Graham-Bermann, Sandra A; Lee, Robert C; Ford, Julian D

    2017-12-01

    The purpose of this study was to examine the co-occurrence of posttraumatic stress disorder (PTSD) and dissociation in a clinical sample of trauma-exposed adolescents by evaluating evidence for the depersonalization/derealization dissociative subtype of PTSD as defined by the DSM-5 and then examining a broader set of dissociation symptoms. A sample of treatment-seeking, trauma-exposed adolescents 12 to 16 years old (N = 3,081) from the National Child Traumatic Stress Network Core Data Set was used to meet the study objectives. Two models of PTSD/dissociation co-occurrence were estimated using latent class analysis, one with 2 dissociation symptoms and the other with 10 dissociation symptoms. After model selection, groups within each model were compared on demographics, trauma characteristics, and psychopathology. Model A, the depersonalization/derealization model, had 5 classes: dissociative subtype/high PTSD; high PTSD; anxious arousal; dysphoric arousal; and a low symptom/reference class. Model B, the expanded dissociation model, identified an additional class characterized by dissociative amnesia and detached arousal. These 2 models provide new information about the specific ways PTSD and dissociation co-occur and illuminate some differences between adult and adolescent trauma symptom expression. A dissociative subtype of PTSD can be distinguished from PTSD alone in adolescents, but assessing a wider range of dissociative symptoms is needed to fully characterize adolescent traumatic stress responses. Copyright © 2017 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

  5. Single-, double-, and triple-photoionization cross sections of carbon monoxide (CO) and ionic fragmentation of CO+, CO2+, and CO3+

    International Nuclear Information System (INIS)

    Masuoka, T.; Nakamura, E.

    1993-01-01

    Single-, double-, and triple-photoionization processes of carbon monoxide (CO) have been studied in the photon-energy region of 37--100 eV by use of time-of-flight mass spectrometry and a photoion-photoion-coincidence method together with synchrotron radiation. The single-, double-, and triple-photoionization cross sections of CO are determined. Ion branching ratios and the partial cross sections for the individual ions respectively produced from the precursors CO + and CO 2+ are determined separately at excitation energies where the molecular and dissociative single- and double-photoionization processes compete. The threshold for the molecular double photoionization was found to be 41.3±0.2 eV. Furthermore, in single photoionization, the production of CO + is dominant whereas with double photoionization dissociation becomes dominant

  6. Collision-induced dissociation of aflatoxins.

    Science.gov (United States)

    Tóth, Katalin; Nagy, Lajos; Mándi, Attila; Kuki, Ákos; Mézes, Miklós; Zsuga, Miklós; Kéki, Sándor

    2013-02-28

    The aflatoxin mycotoxins are particularly hazardous to health when present in food. Therefore, from an analytical point of view, knowledge of their mass spectrometric properties is essential. The aim of the present study was to describe the collision-induced dissociation behavior of the four most common aflatoxins: B1, B2, G1 and G2. Protonated aflatoxins were produced using atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) combined with high-performance liquid chromatography (HPLC). For the tandem mass spectrometry (MS/MS) experiments nitrogen was used as the collision gas and the collision energies were varied in the range of 9-44 eV (in the laboratory frame). The major APCI-MS/MS fragmentations of protonated aflatoxins occurred at 30 eV collision energy. The main fragmentation channels were found to be the losses of a series of carbon monoxide molecules and loss of a methyl radical, leading to the formation of radical-type product ions. In addition, if the aflatoxin molecule contained an ether- or lactone-oxygen atom linked to a saturated carbon atom, loss of a water molecule was observed from the [M + H](+) ion, especially in the case of aflatoxins G1 and G2. A relatively small modification in the structure of aflatoxins dramatically altered the fragmentation pathways and this was particularly true for aflatoxins B1 and B2. Due to the presence of a C = C double bond connected to the ether group in aflatoxin B1 no elimination of water was observed but, instead, formation of radical-type product ions occurred. Fragmentation of protonated aflatoxin B1 yielded the most abundant radical-type cations. Copyright © 2013 John Wiley & Sons, Ltd.

  7. Inter-identity autobiographical amnesia in patients with dissociative identity disorder

    NARCIS (Netherlands)

    Huntjens, R.J.C.; Verschuere, B.; McNally, R.J.

    2012-01-01

    Background A major symptom of Dissociative Identity Disorder (DID; formerly Multiple Personality Disorder) is dissociative amnesia, the inability to recall important personal information. Only two case studies have directly addressed autobiographical memory in DID. Both provided evidence suggestive

  8. Inter-Identity Autobiographical Amnesia in Patients with Dissociative Identity Disorder

    NARCIS (Netherlands)

    Huntjens, R.J.C.; Verschuere, B.; McNally, R.J.

    2012-01-01

    Background: A major symptom of Dissociative Identity Disorder (DID; formerly Multiple Personality Disorder) is dissociative amnesia, the inability to recall important personal information. Only two case studies have directly addressed autobiographical memory in DID. Both provided evidence suggestive

  9. The role of reversed kinematics and double kinematic solutions in nuclear reactions studies

    International Nuclear Information System (INIS)

    Kaplan, M.; Parker, W.E.; Moses, D.J.; Lacey, R.; Alexander, J.M.

    1993-01-01

    The advantages of reversed kinematics in nuclear reactions studies are discussed, with particular emphasis on the origin of double solutions in the reaction kinematics. This possibility for double solutions does not exist in normal kinematics, and provides the basis for a new method of imposing important experimental constraints on the uniqueness of fitting complex observations. By gating on one or the other of the two solutions, light particle kinematics can be greatly influenced in coincidence measurements. The power of the method is illustrated with data for the reaction 1030 MeV 121 Sb+ 27 Al, where charged particle emissions arise from several different sources. (orig.)

  10. Dissociation: a developmental psychoneurobiological perspective

    African Journals Online (AJOL)

    Adele

    ... the stream of con- sciousness and memory.1 It is a frequent symptom of a range ... infant for long time spans in an extremely disturbed psycho- biological state that ... Advantage: Dissociation is adaptive in the short-term. Dissociation can be ...

  11. Dissociation: adjustment or distress? Dissociative phenomena, absorption and quality of life among Israeli women who practice channeling compared to women with similar traumatic history.

    Science.gov (United States)

    Stolovy, Tali; Lev-Wiesel, Rachel; Witztum, Eliezer

    2015-06-01

    This study aimed to explore the relationship between traumatic history, dissociative phenomena, absorption and quality of life among a population of channelers, in comparison with a population of non-channelers with similar traumatic history. The study sample included 150 women. The measures included Traumatic Experiences Scale, Dissociative Experience Scale, Absorption Scale, Brief Symptom Inventory and Quality of Life (QOL) Assessment. Channelers presented significantly higher levels of dissociation, absorption and psychological health compared to the other group. Dissociation and absorption were trauma-related only among the comparison group. Hence, dissociation has different qualities among different people, and spiritual practice contributes to QOL.

  12. Dysregulation in cortical reactivity to emotional faces in PTSD patients with high dissociation symptoms

    Directory of Open Access Journals (Sweden)

    Aleksandra Klimova

    2013-09-01

    Full Text Available Background: Predominant dissociation in posttraumatic stress disorder (PTSD is characterized by restricted affective responses to positive stimuli. To date, no studies have examined neural responses to a range of emotional expressions in PTSD with high dissociative symptoms. Objective: This study tested the hypothesis that PTSD patients with high dissociative symptoms will display increased event-related potential (ERP amplitudes in early components (N1, P1 to threatening faces (angry, fearful, and reduced later ERP amplitudes (Vertex Positive Potential (VPP, P3 to happy faces compared to PTSD patients with low dissociative symptoms. Methods: Thirty-nine civilians with PTSD were classified as high dissociative (n=16 or low dissociative (n=23 according to their responses on the Clinician Administered Dissociative States Scale. ERPs were recorded, whilst participants viewed emotional (happy, angry, fear and neutral facial expressions in a passive viewing task. Results: High dissociative PTSD patients displayed significantly increased N120 amplitude to the majority of facial expressions (neutral, happy, and angry compared to low dissociative PTSD patients under conscious and preconscious conditions. The high dissociative PTSD group had significantly reduced VPP amplitude to happy faces in the conscious condition. Conclusion: High dissociative PTSD patients displayed increased early (preconscious cortical responses to emotional stimuli, and specific reductions to happy facial expressions in later (conscious, face-specific components compared to low dissociative PTSD patients. Dissociation in PTSD may act to increase initial pre-attentive processing of affective stimuli, and specifically reduce cortical reactivity to happy faces when consciously processing these stimuli.

  13. A single dose desensitization for summer hay fever. Results of a double blind study-1988.

    Science.gov (United States)

    Fell, P; Brostoff, J

    1990-01-01

    A new type of desensitising vaccine, enzyme potentiated was subjected to a double-blind randomised study during the hay fever season. The vaccine is a convenient single injection given in March and the results show good protection throughout the grass pollen season.

  14. Rotating double arm spectrometer to study hard scattering interactions at Serpukhov accelerator

    International Nuclear Information System (INIS)

    Abramov, V.V.; Baldin, B.Yu.; Buzulutskov, A.F.

    1991-01-01

    The double arm magnetic spectrometer designed to study high P T particle production with intense proton and pion beams is described. Particle trajectories are measured by the drift and proportional chambers. Particles are identified by Cherenkov ring spectrometer and muon identifier. The spectrometer can be rotated around the target up to 160 mrad. 2 tabs.; 13 figs

  15. Preliminary Heat Transfer Studies for the Double Shell Tanks (DST) Transfer Piping

    International Nuclear Information System (INIS)

    HECHT, S.L.

    2000-01-01

    Heat transfer studies were made to determine the thermal characteristics of double-shell tank transfer piping under both transient and steady-state conditions. A number of design and operation options were evaluated for this piping system which is in its early design phase

  16. A double-blind, placebo-controlled study of sertraline with naltrexone for alcohol dependence.

    LENUS (Irish Health Repository)

    Farren, Conor K

    2009-01-01

    Significant preclinical evidence exists for a synergistic interaction between the opioid and the serotonin systems in determining alcohol consumption. Naltrexone, an opiate receptor antagonist, is approved for the treatment of alcohol dependence. This double-blind placebo-controlled study examined whether the efficacy of naltrexone would be augmented by concurrent treatment with sertraline, a selective serotonin receptor uptake inhibitor (SSRI).

  17. Mefloquine prophylaxis prevents malaria during pregnancy: a double-blind, placebo-controlled study

    NARCIS (Netherlands)

    Nosten, F.; ter Kuile, F.; Maelankiri, L.; Chongsuphajaisiddhi, T.; Nopdonrattakoon, L.; Tangkitchot, S.; Boudreau, E.; Bunnag, D.; White, N. J.

    1994-01-01

    A double-blind, placebo-controlled study of mefloquine antimalarial prophylaxis in pregnancy (> 20 weeks of gestation) was conducted in 339 Karen women living in an area of multidrug-resistant malaria transmission on the Thai-Burmese border. Mefloquine gave > or = 86% (95% confidence interval [CI],

  18. ULTRAVIOLET TRANSITIONS IN EUROPIUM STUDIED WITH A FREQUENCY-DOUBLED CW RING DYE-LASER

    NARCIS (Netherlands)

    Eliel, E.R.; Hogervorst, W.; van Leeuwen, K.A.H.; Post, B.H.

    1981-01-01

    High resolution laser spectroscopy has been applied to the study of three ultraviolet transitions in Europium at λ = 294.8, 295.1 and 295.8 nm. The tunable narrowband UV has been generated by intracavity frequency doubling in a cw ring dye laser using a temperate tuned, Brewster angled ADA crystal.

  19. Human norovirus inactivation in oysters by high hydrostatic pressure processing: A randomized double-blinded study

    Science.gov (United States)

    This randomized, double-blinded, clinical trial assessed the effect of high hydrostatic pressure processing (HPP) on genogroup I.1 human norovirus (HuNoV) inactivation in virus-seeded oysters when ingested by subjects. The safety and efficacy of HPP treatments were assessed in three study phases wi...

  20. Preparation, characterization and thermal behaviour study of double selenates of lanthanides, yttrium and beryllium

    International Nuclear Information System (INIS)

    Ribeiro, C.A.

    1988-01-01

    The lanthanides (III) and yttrium (III) double selenates were studied using common analytical methods, atomic absorption, X-ray diffraction infra-red absorption, thermogravimetry and differential thermal analysis. These compounds were prepared from the mixture of lanthanides (III) and yttrium (III) selenates aqueous solution and basic beryllium selenates aqueous solution, obeying equimolar relation (1:1) to the cation

  1. Double-Wavelet Approach to Studying the Modulation Properties of Nonstationary Multimode Dynamics

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Mosekilde, Erik; Pavlov, A.N.

    2005-01-01

    On the basis of double-wavelet analysis, the paper proposes a method to study interactions in the form of frequency and amplitude modulation in nonstationary multimode data series. Special emphasis is given to the problem of quantifying the strength of modulation for a fast signal by a coexisting...

  2. Quarkonium suppression: Gluonic dissociation vs. colour screening

    Indian Academy of Sciences (India)

    mechanism comes into play for the initial conditions taken from the self screened parton cascade model in these studies. Keywords. Quark gluon plasma; J ψ; suppression; dissociation; colour screening. PACS No. 12.38.M. 1. Introduction. The last two decades have seen hectic activity towards identifying unique signatures ...

  3. Resonances in dissociative recombination: Trends and patterns

    Energy Technology Data Exchange (ETDEWEB)

    Orel, A E; Ngassam, V; Royal, J [Department of Applied Science, University of California, Davis (United States); Roos, J B; Larson, A, E-mail: aeorel@ucdavis.ed [Department of Theoretical Chemistry, Royal Institute of Technology, Stockholm (Sweden)

    2009-11-15

    In dissociative recombination, the kinetic energy of the incident electron is transferred into excitation of the electrons of the target ion and then into kinetic energy of the fragments. In general, this proceeds via a resonance where the electron is temporarily trapped by the ion, leading to efficient energy transfer. The study of dissociative recombination is the study of these resonances, Rydberg states converging to the ground and excited states of the ion. For a number of systems, we have studied the electronic states involved in dissociative recombination, including the ground and excited states of the ion, the resonant states and the bound Rydberg states of the system, by combining electron scattering calculations with multi-reference configuration interaction quantum chemistry calculations. We will report on trends and patterns in these resonance states. We will discuss studies of dissociative recombination of the rare-gas ions, moving down the periodic table from He{sup +}{sub 2} to Ne{sup +}{sub 2} to Ar{sup +}{sub 2}, where the ground electronic state of the ion is constant, but its polarizability increases. We will also present results on isoelectronic polyatomic systems, such as HCO{sup +} and HCNH{sup +}, as well as the effects of changing the electronic structure slightly such as HCN{sup +}/HNC{sup +} and H{sub 2}CO{sup +}.

  4. Quarkonium dissociation by anisotropy

    Science.gov (United States)

    Chernicoff, Mariano; Fernández, Daniel; Mateos, David; Trancanelli, Diego

    2013-01-01

    We compute the screening length for quarkonium mesons moving through an anisotropic, strongly coupled mathcal{N} = 4 super Yang-Mills plasma by means of its gravity dual. We present the results for arbitrary velocities and orientations of the mesons, as well as for arbitrary values of the anisotropy. The anisotropic screening length can be larger or smaller than the isotropic one, and this depends on whether the comparison is made at equal temperatures or at equal entropy densities. For generic motion we find that: (i) mesons dissociate above a certain critical value of the anisotropy, even at zero temperature; (ii) there is a limiting velocity for mesons in the plasma, even at zero temperature; (iii) in the ultra-relativistic limit the screening length scales as (1 - v 2)ɛ with ɛ = 1 /2, in contrast with the isotropic result ɛ = 1 /4.

  5. Radiographer and radiologist perception error in reporting double contrast barium enemas: A pilot study

    International Nuclear Information System (INIS)

    Booth, Alison M.; Mannion, Richard A.J.

    2005-01-01

    Purpose: The practice of radiographers performing double contrast barium enemas (DCBE) is now widespread and in many centres the radiographer's opinion is, at least, contributing to a dual reporting system [Bewell J, Chapman AH. Radiographer performed barium enemas - results of a survey to assess progress. Radiography 1996;2:199-205; Leslie A, Virjee JP. Detection of colorectal carcinoma on double contrast barium enema when double reporting is routinely performed: an audit of current practice. Clin Radiol 2001;57:184-7; Culpan DG, Mitchell AJ, Hughes S, Nutman M, Chapman AH. Double contrast barium enema sensitivity: a comparison of studies by radiographers and radiologists. Clin Radiol 2002;57:604-7]. To ensure this change in practice does not lead to an increase in reporting errors, this study aimed to compare the perception abilities of radiographers with those of radiologists. Methods: Three gastro-intestinal (GI) radiographers and three consultant radiologists independently reported on a selection of 50 DCBE examinations, including the level of certainty in their comments for each examination. A blinded comparison of the results with an independent 'standard report' was recorded. Results: The results demonstrate there was no significant difference in perception error for any of the levels of certainty, for single reporting, for double reading by a radiographer/radiologist or by two radiologists. Conclusions: The study shows that radiographers can perceive abnormalities on DCBE at similar sensitivities and specificities as radiologists. While the participants in the study may be typical of a district general hospital, the nature of the study gives it limited external validity. As a pilot, the results demonstrate that, with slight modification, the methodology could be used for a larger study

  6. A double-mutant collection targeting MAP kinase related genes in Arabidopsis for studying genetic interactions.

    Science.gov (United States)

    Su, Shih-Heng; Krysan, Patrick J

    2016-12-01

    Mitogen-activated protein kinase cascades are conserved in all eukaryotes. In Arabidopsis thaliana there are approximately 80 genes encoding MAP kinase kinase kinases (MAP3K), 10 genes encoding MAP kinase kinases (MAP2K), and 20 genes encoding MAP kinases (MAPK). Reverse genetic analysis has failed to reveal abnormal phenotypes for a majority of these genes. One strategy for uncovering gene function when single-mutant lines do not produce an informative phenotype is to perform a systematic genetic interaction screen whereby double-mutants are created from a large library of single-mutant lines. Here we describe a new collection of 275 double-mutant lines derived from a library of single-mutants targeting genes related to MAP kinase signaling. To facilitate this study, we developed a high-throughput double-mutant generating pipeline using a system for growing Arabidopsis seedlings in 96-well plates. A quantitative root growth assay was used to screen for evidence of genetic interactions in this double-mutant collection. Our screen revealed four genetic interactions, all of which caused synthetic enhancement of the root growth defects observed in a MAP kinase 4 (MPK4) single-mutant line. Seeds for this double-mutant collection are publicly available through the Arabidopsis Biological Resource Center. Scientists interested in diverse biological processes can now screen this double-mutant collection under a wide range of growth conditions in order to search for additional genetic interactions that may provide new insights into MAP kinase signaling. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  7. Dissociation - a preliminary contextual model

    Directory of Open Access Journals (Sweden)

    C Krüger

    2007-02-01

    Full Text Available Background. The Diagnostic and Statistical Manual of Mental Disorders (DSM system has certain limitations when applied to two South African examples of dissociation, because it is descriptive (non-explanatory and focuses on intrapsychic (non-communal processes. Even the existing Western explanatory models of dissociation fail to accommodate fully the communal aspects of dissociation in our South African context. Objectives and methods. The aim was to explore an expanded perspective on dissociation that does not limit it to an intrapsychic phenomenon, but that accounts for the interrelatedness of individuals within their social context. Auto-ethnography was used. In this article a collective, socially orientated, contextual hermeneutic was applied to two local examples of dissociation. Three existing Western models were expanded along multicontextual, collective lines, for them to be more useful in the pluralistic South African context. Results. This preliminary contextual model of dissociation includes a person’s interpersonal, socio-cultural, and spiritual contexts, in addition to the intrapsychic context. Dissociation is considered to be a normal information-processing tool that maintains balanced, coherent selves-in-society, i.e. individuals connected to each other. In the South African context dissociation appears mostly as a normal phenomenon and seldom as a sign of mental illness. Dissociation is pivotal for the normal construction of individual and communal identities in the face of conflicting sets of information from various contexts. Dissociation may help individuals or communities to survive in a world of conflicting messages, where conflict is often interpersonal/cultural/societal in nature, rather than primarily intrapsychic. Conclusions. This model should be developed and evaluated further. Such evaluation would require suitable new local terminology.

  8. Assessment of dissociation in Bosnian treatment-seeking refugees in Denmark.

    Science.gov (United States)

    Palic, Sabina; Carlsson, Jessica; Armour, Cherie; Elklit, Ask

    2015-05-01

    Dissociative experiences are common in traumatized individuals, and can sometimes be mistaken for psychosis. It is difficult to identify pathological dissociation in the treatment of traumatized refugees, because there is a lack of systematic clinical descriptions of dissociative phenomena in refugees. Furthermore, we are currently unaware of how dissociation measures perform in this clinical group. To describe the phenomenology of dissociative symptoms in Bosnian treatment-seeking refugees in Denmark. As a part of a larger study, dissociation was assessed systematically in 86 Bosnian treatment-seeking refugees using a semi-structured clinical interview (Structured Interview for Disorders of Extreme Stress-dissociation subscale; SIDES-D) and a self-report scale (Dissociative Experiences Scale; DES). The SIDES-D indicated twice as high prevalence of pathological dissociation as the DES. According to the DES, 30% of the refugees had pathological dissociation 15 years after their resettlement. On the SIDES-D, depersonalization and derealization experiences were the most common. Also, questions about depersonalization and derealization at times elicited reporting of visual and perceptual hallucinations, which were unrelated to traumatic re-experiencing. Questions about personality alteration elicited spontaneous reports of a phenomenon of "split" pre- and post-war identity in the refugee group. Whether this in fact is a dissociative phenomenon, characteristic of severe traumatization in adulthood, needs further examination. Knowledge of dissociative symptoms in traumatized refugees is important in clinical settings to prevent misclassification and to better target psychotherapeutic interventions. Much development in the measurement of dissociation in refugees is needed.

  9. Dissociation of brain edema induced by cold injury in rat model. MR imaging and perfusion studies with 14C-iodo-antipyrine

    International Nuclear Information System (INIS)

    Itabashi, Yoko; Prado, G.L.M.; Abo, Mitsuru; Miura, Hiroyuki; Abe, Yoshinao

    2001-01-01

    The purpose of this study is to confirm whether T2-weighted imaging and perfusion imaging, i.e. autoradiogram of 14 C-iodoantipyrine, on the course of brain edema correspond to each other or not. Cold injured rat brains were used as a model and were sequentially examined by both methods and compared with each other and with histological specimens. Special focus relies on the time changes in the lesions. High SI of T2-weighted images were observed and the percentages in the high SI area to the total brain area in the same slice were 4.7±0.31, 5.6±0.46 and 3.4±0.42 for 6, 24 and 48 hours, respectively. By contrast, low perfusion areas were indicated in the perfusion study and their percentages were 4.6±0.55, 5.6±0.86 and 2.4±0.35 for 6, 24 and 48 hours, respectively. At 48 hours after cold injury, low perfusion areas were smaller than high SI areas. Moreover, high accumulation areas consisting of macrophages were observed surrounding necrosis. It is concluded that there is dissociation between perfusion and T2-weighted MR imaging, where the collection of macrophages surrounding edema lesions and necrosis had the same appearance on MRI and different accumulations on perfusion studies. (author)

  10. Dissociative, depressive, and PTSD symptom severity as correlates of nonsuicidal self-injury and suicidality in dissociative disorder patients.

    Science.gov (United States)

    Webermann, Aliya R; Myrick, Amie C; Taylor, Christina L; Chasson, Gregory S; Brand, Bethany L

    2016-01-01

    The present study investigates whether symptom severity can distinguish patients diagnosed with dissociative identity disorder and dissociative disorder not otherwise specified with a recent history of nonsuicidal self-injury (NSSI) and suicide attempts from those patients without recent self-harm. A total of 241 clinicians reported on recent history of patient NSSI and suicide attempts. Of these clinicians' patients, 221 completed dissociative, depressive, and posttraumatic stress disorder symptomatology measures. Baseline cross-sectional data from a naturalistic and prospective study of dissociative disorder patients receiving community treatment were utilized. Analyses evaluated dissociative, depressive, and posttraumatic stress disorder symptom severity as methods of classifying patients into NSSI and suicide attempt groupings. Results indicated that dissociation severity accurately classified patients into NSSI and suicidality groups, whereas depression severity accurately classified patients into NSSI groups. These findings point to dissociation and depression severity as important correlates of NSSI and suicidality in patients with dissociative disorders and have implications for self-harm prevention and treatment.

  11. The return of dissociation as absence within absence.

    Science.gov (United States)

    Gurevich, Hayuta

    2014-12-01

    My aim is to translate Ferenczi's central concepts of the intrapsychic impact and imprint of early developmental trauma into both revived and contemporary conceptualizations. The concept of dissociation was renounced by Freud, yet it is returning as a cornerstone of recent trauma theories. Ferenczi used the concept of "repression," but used it in the sense of an intrapsychic imprint of early external trauma that fragments consciousness, that is, as dissociation. Furthermore, early trauma is double: an absence of protection that threatens existence of the self, combined with an absence of attachment and of recognition of this threat and terror; thus it is an absence-within-absence. This contemporary conceptualization entails a widening of the intrapsychic realm to include an intersubjective one, and regards dissociation as a unique and complex intrapsychic absence, which is a negative of the external absence-within-absence in the early environment.

  12. Unresolved mourning, supernatural beliefs and dissociation: a mediation analysis.

    Science.gov (United States)

    Thomson, Paula; Jaque, S Victoria

    2014-01-01

    Unresolved mourning is marked by disorganized behavior and states of mind. In this study, we speculated that pathological dissociation would mediate the effects of unresolved mourning on supernatural beliefs. This hypothesis was determined based on findings that indicate an association between higher levels of dissociation, stronger beliefs in the supernatural and unresolved mourning. We examined two groups of participants, one classified as non-unresolved (non-U) (n = 56) and the other as unresolved (n = 26) (U) with respect to past loss/trauma as measured by the Adult Attachment Interview (AAI). Two self-report instruments were administered to measure supernatural beliefs and dissociation. As hypothesized, the multivariate analysis of variance indicated mean differences between the two groups. The unresolved group had greater belief in the supernatural and more pathological dissociative processes. The mediation analysis demonstrated that pathological dissociation fully mediated the effects of unresolved mourning on supernatural beliefs.

  13. Symmetry Breakdown in Ground State Dissociation of HD+

    International Nuclear Information System (INIS)

    Ben-Itzhak, I.; Wells, E.; Carnes, K. D.; Krishnamurthi, Vidhya; Weaver, O. L.; Esry, B. D.

    2000-01-01

    Experimental studies of the dissociation of the electronic ground state of HD + following ionization of HD by fast proton impact indicate that the H + +D 1s dissociation channel is more likely than the H1s+D + dissociation channel by about 7% . This isotopic symmetry breakdown is due to the finite nuclear mass correction to the Born-Oppenheimer approximation which makes the 1sσ state 3.7 meV lower than the 2pσ state at the dissociation limit. The measured fractions of the two dissociation channels are in agreement with coupled-channels calculations of 1sσ to 2pσ transitions. (c) 2000 The American Physical Society

  14. On film quality in barium-air double contrast colon study

    International Nuclear Information System (INIS)

    Rhu, Sang Hyung; Rhee, Jae Ho; Kim, Hai Sung; Cheung, Hwan

    1984-01-01

    The colon double contrast study provides valuable diagnostic information by means of appropriate control of Kvp and mAa when making double contrast image by injecting air into the colon after coating the colon wall by appropriately diluted Barium solution. The following experiments were performed the results of which allowed to improve the quality of film in barium-air double contrast colon study: (1) Do the pictures have uniform density when measured with a densitometer from three measuring points established in the picture by changing Kvp and mAs depending on the thickness of the patient? (2) Is the quality of the picture improved by being compensated from the adjacent area when using a wedge filter in routine check lateral decubitus and erect view? (3) What is the optimum dilution of barium solution which gives the best result for colon wall coating? The above experiments revealed that as the patient's thickness increased, it should be considered to increase mAs as well as Kvp and a wedge filter could give diagnostically very informative pictures in routine-check lateral decubitus and erect view. And 70-80% solution of Barium-water mixture provided the best quality of double contrast image

  15. Fast MAS 1H NMR Study of Water Adsorption and Dissociation on the (100) Surface of Ceria Nanocubes: A Fully Hydroxylated, Hydrophobic Ceria Surface

    Energy Technology Data Exchange (ETDEWEB)

    Gill, Lance [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division; Beste, Ariana [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Joint Institute for Computational Sciences (JIBS); Univ. of Tennessee, Knoxville, TN (United States); Chen, Banghao [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division; Li, Meijun [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division; Mann, Amanda K. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division; Overbury, Steven H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division; Hagaman, Edward W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division

    2017-03-22

    1H nuclear magnetic resonance (NMR) spectroscopy was used to study hydroxylic surface species on ceria nanocubes, a crystalline, high-surface-area CeO2 that presents mostly (100) facets. Water adsorption and desorption experiments in combination with fast magic angle spinning (MAS, 20–40 kHz) 1H NMR provide high-resolution 1H spectra that allow the observation of ten resonance bands (water or hydroxyl) on or under the (100) surface. Assignments were made using a combination of adsorption and temperature-programmed desorption, quantitative spin counting, deuterium exchange, spin–lattice (T1) and spin–spin (T2) relaxation, and DFT calculations. In air, the (100) surface exists as a fully hydroxylated surface. Water adsorption and dissociation on dry ceria surfaces occur first at oxygen vacancies, but Ce3+ centers are not required since water dissociation is barrier-less on the fully oxidized surface. Surface $-$OH functionality occurs in two resolved bands representing isolated $-$OH (1 ppm) and hydrogen-bonded $-$OH (9 ppm), the latter being dominant. Deuterium exchange of surface hydroxyls with D2O does not occur under mild or forcing conditions. Despite large differences in the T1 of surface hydroxyls and physisorbed water, surface hydroxyl T1 values are independent of the presence or absence of physisorbed water, demonstrating that the protons within these two functional group pools are not in intimate contact. These observations show that, once hydroxylated, the surface $-$OH functionality preferentially forms hydrogen bonds with surface lattice oxygen, i.e., the hydroxylated (100) surface of ceria is hydrophobic. Near this surface it is energetically more favorable for physisorbed water to hydrogen bond to itself rather than to the surface. DFT calculations support this notion. Impurity Na+ remaining in incompletely washed ceria nanocubes

  16. Competition between dissociation paths of I2+ NO+ using fast laser fields

    International Nuclear Information System (INIS)

    Lev, U; Prabhudesai, V S; Natan, A; Schwalm, D; Bruner, B D; Silberberg, Y; Heber, O; Zajfman, D; Zohrabi, M; Gaire, B; Carnes, K D; Ben-Itzhak, I; Strasser, D

    2012-01-01

    The competition between dissociation paths of I 2 + and NO + molecules was studied using femtosecond laser pulses with different intensities. It was found, both for moderate fields and for strong fields, that the dissociation path strongly prefers the higher energy dissociation path with smaller kinetic energy rather than the lower energy path with higher kinetic energy.

  17. Study on Relative COP Changes with Increasing Heat Input Temperatures of Double Effect Steam Absorption Chillers

    Directory of Open Access Journals (Sweden)

    Abd Majid Mohd Amin

    2016-01-01

    Full Text Available Absorption chillers at cogeneration plants generate chilled water using steam supplied by heat recovery steam generators. The chillers are mainly of double effect type. The COP of double effect varies from 0.7 to 1.2 depending on operation and maintenance practices of the chillers. Heat input to the chillers during operations could have impact on the COP of the chillers. This study is on relative COP changes with increasing the heat input temperatures for a steam absorption chiller at a gas fueled cogeneration plant. Reversible COP analysis and zero order model were used for evaluating COP of the chiller for 118 days operation period. Results indicate increasing COP trends for both the reversible COP and zero model COP. Although the zero model COP are within the range of double effect absorption chiller, it is not so for the actual COP. The actual COP is below the range of normal double effect COP. It is recommended that economic replacement analysis to be undertaken to assess the feasibility either to repair or replace the existing absorption chiller.

  18. Effective field study of ising model on a double perovskite structure

    Energy Technology Data Exchange (ETDEWEB)

    Ngantso, G. Dimitri; El Amraoui, Y. [LMPHE, (URAC 12), Faculté des Sciences, Université Mohammed V, Rabat (Morocco); Benyoussef, A. [LMPHE, (URAC 12), Faculté des Sciences, Université Mohammed V, Rabat (Morocco); Center of Materials and Nanomaterials, MAScIR, Rabat (Morocco); Hassan II Academy of Science and Technology, Rabat (Morocco); El Kenz, A., E-mail: elkenz@fsr.ac.ma [LMPHE, (URAC 12), Faculté des Sciences, Université Mohammed V, Rabat (Morocco)

    2017-02-01

    By using the effective field theory (EFT), the mixed spin-1/2 and spin-3/2 Ising ferrimagnetic model adapted to a double perovskite structure has been studied. The EFT calculations have been carried out from Ising Hamiltonian by taking into account first and second nearest-neighbors interactions and the crystal and external magnetic fields. Both first- and second-order phase transitions have been found in phase diagrams of interest. Depending on crystal-field values, the thermodynamic behavior of total magnetization indicated the compensation phenomenon existence. The hysteresis behaviors are studied by investigating the reduced magnetic field dependence of total magnetization and a series of hysteresis loops are shown for different reduced temperatures around the critical one. - Highlights: • Magnetic properties of double perovskite Structure have been studied. • Compensation temperature has been observed below the critical temperature. • Hysteresis behaviors have been studied.

  19. Effective field study of ising model on a double perovskite structure

    International Nuclear Information System (INIS)

    Ngantso, G. Dimitri; El Amraoui, Y.; Benyoussef, A.; El Kenz, A.

    2017-01-01

    By using the effective field theory (EFT), the mixed spin-1/2 and spin-3/2 Ising ferrimagnetic model adapted to a double perovskite structure has been studied. The EFT calculations have been carried out from Ising Hamiltonian by taking into account first and second nearest-neighbors interactions and the crystal and external magnetic fields. Both first- and second-order phase transitions have been found in phase diagrams of interest. Depending on crystal-field values, the thermodynamic behavior of total magnetization indicated the compensation phenomenon existence. The hysteresis behaviors are studied by investigating the reduced magnetic field dependence of total magnetization and a series of hysteresis loops are shown for different reduced temperatures around the critical one. - Highlights: • Magnetic properties of double perovskite Structure have been studied. • Compensation temperature has been observed below the critical temperature. • Hysteresis behaviors have been studied.

  20. Comparison between single-row and double-row rotator cuff repair: a biomechanical study.

    Science.gov (United States)

    Milano, Giuseppe; Grasso, Andrea; Zarelli, Donatella; Deriu, Laura; Cillo, Mario; Fabbriciani, Carlo

    2008-01-01

    The aim of this study was to compare the mechanical behavior under cyclic loading test of single-row and double-row rotator cuff repair with suture anchors in an ex-vivo animal model. For the present study, 50 fresh porcine shoulders were used. On each shoulder, a crescent-shaped full-thickness tear of the infraspinatus was performed. Width of the tendon tear was 2 cm. The lesion was repaired using metal suture anchors. Shoulders were divided in four groups, according the type of repair: single-row tension-free repair (Group 1); single-row tension repair (Group 2); double-row tension-free repair (Group 3); double-row tension repair (Group 4); and a control group. Specimens were subjected to a cyclic loading test. Number of cycles at 5 mm of elongation and at failure, and total elongation were calculated. Single-row tension repair showed significantly poorest results for all the variables considered, when compared with the other groups. Regarding the mean number of cycles at 5 mm of elongation and at failure, there was a nonsignificant difference between Groups 3 and 4, and both of them were significantly greater than Group 1. For mean total elongation, the difference between Groups 1, 3, and 4 was not significant, but all of them were significantly lower than the control group. A single-row repair is particularly weak when performed under tension. Double-row repair is significantly more resistant to cyclic displacement than single-row repair in both tension-free and tension repair. Double-row repair technique can be primarily considered for large, unstable rotator cuff tears to improve mechanical strength of primary fixation of tendons to bone.

  1. A DFT study of Ru, Rh, Pd, Os, Ir, and Pt clusters as catalysts for methane dissociation in a direct methane fuel cell (DMHFC)

    Energy Technology Data Exchange (ETDEWEB)

    Psofogiannakisa, G. [Ottawa Univ., Ottawa, ON (Canada). Dept. of Chemical Engineering; Ottawa, Univ., Ottawa, ON (Canada). Centre for Catalysis Research and Innovation; St-Amant, A. [Ottawa Univ., Ottawa, ON (Canada). Dept. of Chemistry; Ternan, M. [Ottawa Univ., Ottawa, ON (Canada). Centre for Catalysis Research and Innovation; EnPross Inc., Ottawa, ON (Canada)

    2008-07-01

    The rate limiting step in a direct methane hydrocarbon fuel cell (DMHFC) is the dissociative chemisorption of methane. Quantum mechanical computations were used to examine the terrace, kink, and step sites on 6 different clusters of group 8 transition metals, notably Ru, Rh, Pd, Os, Ir, and Pt. The computations involved the anodic reaction of a DMHFC with a polymer electrolyte that operates at atmospheric pressure and temperatures higher than 120 degrees C. The interaction between molecular fragments and a surface (Pt) were described and density functional theory (DFT) calculations were performed using Guassian software. The geometries of 5 different platinum clusters were examined along with their electronic energy barriers. The biggest contribution to the stabilization energy came from the overlap between the sigma bond in methane and unoccupied sd hybrid orbitals in the Pt bonding atom. The study showed that when relaxation was allowed, the displacement of the bonding metal atom was 0.36 to 0.52 A. The electronic energy barrier often increased as d-orbital occupancy increased. For the kink surface sites, the energy barriers were considerably smaller for the 5d transition metals than for the 4d transition metals. 5 refs., 1 tab.

  2. Can the DSM-5 differentiate between nonpathological possession and dissociative identity disorder? A case study from an Afro-Brazilian religion.

    Science.gov (United States)

    Delmonte, Romara; Lucchetti, Giancarlo; Moreira-Almeida, Alexander; Farias, Miguel

    2016-01-01

    The aim of this article is to examine whether the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), are able to differentiate between nonpathological religious possession and dissociative identity disorder (DID). We use the case study of an individual who leads an Afro-Brazilian religious group (Umbanda), focusing on her personal development and possession experiences from early childhood to the present, spanning a period of more than 40 years, and examine these data following DSM-5 criteria for DID (300.14). Her experiences of possession can be broken into 2 distinct stages. In the 1st stage (childhood and early adulthood), she displayed intrusive thoughts and a lack of control over possession states, which were associated with a heightened state of anxiety, loneliness, amnesia, and family conflict (meeting all 5 criteria for DID). In the 2nd stage (late 20s up to the present), she regularly experienced possession states but felt in control of their onset and found them religiously meaningful. In this 2nd stage, she only fulfilled 3 criteria for DID. We question the accuracy of diagnosing this individual with DID in her earlier life and suggest that the DSM-5 criteria fail to address the ambiguity of affect surrounding possession experiences (positive at the individual level, negative at the interpersonal level) and lack a clearer acknowledgment of the prevalence of possession and other unusual experiences in general populations.

  3. The Relationship Between Apraxia of Speech and Oral Apraxia: Association or Dissociation?

    Science.gov (United States)

    Whiteside, Sandra P; Dyson, Lucy; Cowell, Patricia E; Varley, Rosemary A

    2015-11-01

    Acquired apraxia of speech (AOS) is a motor speech disorder that affects the implementation of articulatory gestures and the fluency and intelligibility of speech. Oral apraxia (OA) is an impairment of nonspeech volitional movement. Although many speakers with AOS also display difficulties with volitional nonspeech oral movements, the relationship between the 2 conditions is unclear. This study explored the relationship between speech and volitional nonspeech oral movement impairment in a sample of 50 participants with AOS. We examined levels of association and dissociation between speech and OA using a battery of nonspeech oromotor, speech, and auditory/aphasia tasks. There was evidence of a moderate positive association between the 2 impairments across participants. However, individual profiles revealed patterns of dissociation between the 2 in a few cases, with evidence of double dissociation of speech and oral apraxic impairment. We discuss the implications of these relationships for models of oral motor and speech control. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Parents' descriptions of young children's dissociative reactions after trauma.

    Science.gov (United States)

    Cintron, Gabriela; Salloum, Alison; Blair-Andrews, Zoe; Storch, Eric A

    2017-10-09

    There is limited research on the phenomenology of how young children who have been exposed to trauma express the intrusive symptom of dissociative reactions. The current qualitative study utilized interviews from a semi-structured diagnostic clinical interview with 74 caregivers of young children (ages 3 to 7) who were exposed to trauma to identify parents' descriptions of their children's dissociative reactions during a clinical interview. Based on results from the interview, 45.9% of the children had dissociative reactions (8.5% had flashbacks and 41.9% had dissociative episodes). Interviews were transcribed to identify themes of dissociative reactions in young children. Common themes to flashbacks and dissociative episodes included being triggered, being psychologically in their own world (e.g., spaced out and shut down), and displaying visible signs (e.g., crying and screaming). For flashbacks, caregivers reported that it seemed as if the child was re-experiencing the trauma (e.g., yelling specific words and having body responses). For dissociative episodes, caregivers noted that the child not only seemed psychologically somewhere else (e.g., distant and not there) but also would be physically positioned somewhere else (e.g., sitting and not responding). Caregivers also expressed their own reactions to the child's dissociative episode due to not understanding what was occurring, and trying to interrupt the occurrences (e.g., calling out to the child). Themes, descriptions, and phrases to describe dissociative reactions in young children after trauma can be used to help parents and professionals more accurately identify occurrences of dissociative reactions.

  5. Dynamics of NO2 dissociation. Study by resonance-enhanced multi-photon ionisation of energy distribution and of anisotropies in fragments

    International Nuclear Information System (INIS)

    Mons, Michel

    1988-01-01

    In this research thesis, the author reports the use of laser resonance-enhanced multi-photon ionization and of time-of-flight mass spectrometry for a detailed characterization of fragments produced by a photo-dissociation process. The author more particularly addressed the case of a NO 2 molecule excited at low energies above the dissociation threshold. In the first part, the author discusses issues and problems related to molecular photo-dissociation. In the second part, he presents the developed method and shows that the combined use of both techniques allows a precise characterisation of photo-fragments in terms of internal or translational energies as well as in terms of angle distributions. Finally, the author presents and discusses results obtained in the case of NO 2 [fr

  6. A comparative theoretical study of exciton-dissociation and charge-recombination processes in oligothiophene/fullerene and oligothiophene/perylenediimide complexes for organic solar cells

    KAUST Repository

    Yi, Yuanping

    2011-01-01

    The exciton-dissociation and charge-recombination processes in donor-acceptor complexes found in α-sexithienyl/C60 and α-sexithienyl/perylenetetracarboxydiimide (PDI) solar cells are investigated by means of quantum-chemical methods. The electronic couplings and exciton-dissociation and charge-recombination rates have been evaluated for various configurations of the complexes. The results suggest that the decay of the lowest charge-transfer state to the ground state in the PDI-based devices: (i) is faster than that in the fullerene-based devices and (ii) in most cases, can compete with the dissociation of the charge-transfer state into mobile charge carriers. This faster charge-recombination process is consistent with the lower performance observed experimentally for the devices using PDI derivatives as the acceptor. © 2011 The Royal Society of Chemistry.

  7. Lifetime and kinetic energy release of metastable dications dissociation

    International Nuclear Information System (INIS)

    Alagia, M.; Candori, P.; Falcinelli, S.; Mundim, K.C.; Mundim, M.S.P.; Pirani, F.; Richter, R.; Stranges, S.; Vecchiocattivi, F.

    2012-01-01

    Graphical abstract: A statistical method is proposed for extracting dynamics information from coincidence data in double photoionization of molecules. Highlights: ► When a photon, with sufficient energy, hits a molecule, a doubly charged ion can be formed. This dication has often a large probability of dissociate in two positive singly charged ions. ► Experiments of photoelectron–photoion–photoion coincidence can provide valuable information about the dynamics of such dissociation processes. ► A statistical method is proposed for extracting such information from the coincidence data. - Abstract: A new method for the determination of dynamical features of the molecular dication dissociation processes, following the single photon double ionization, investigated by time-of-flight mass spectrometry technique has been developed. The method is based on an extension of the generalized simulated annealing statistical methodology, previously applied in other fields. Here it is described and applied, as an example, to the case of the dissociation of the CO 2 2+ dication giving CO + + O + ion fragments. The results are consistent with previous determination of the metastable lifetime of the dication, but the analysis also provides additional information about the dynamics of the reaction.

  8. [Questionnaire on dissociative symptoms. German adaptation, reliability and validity of the American Dissociative Experience Scale (DES)].

    Science.gov (United States)

    Freyberger, H J; Spitzer, C; Stieglitz, R D; Kuhn, G; Magdeburg, N; Bernstein-Carlson, E

    1998-06-01

    The "Fragebogen zu dissoziativen Symptomen (FDS)" represents the authorised German translation and adaptation of the "Dissociative Experience Scale" (DES; Bernstein and Putnam 1986). The original scale comprises 28 items covering dissociative experiences with regard to memory, identity, awareness and cognition according to DSM-III-R and DSM-IV. For the German version, 16 items were added to cover dissociative phenomena according to ICD-10, mainly pseudoneurological conversion symptoms. Reliability and validity of the German version were studied in a total sample of 813 persons and were compared to the results of the original version. Test-retest reliability of the FDS was rtt = 0.88 and Cronbach's consistency coefficient was alpha = 0.93, which is comparable to the results of the DES. The instrument differentiates between different samples (healthy control subjects, students, unselected neurological and psychiatric inpatients, neurological and psychiatric patients with a dissociative disorder and schizophrenics). The FDS is an easily applicable, reliable and valid measure to quantify dissociative experiences.

  9. Granulomatous colitis: findings on double contrast barium enema and follow-up studies

    International Nuclear Information System (INIS)

    Song, Jong Gi; Han, Joon Koo; Kim, Seung Hoon; Choo, Sung Wook; Kim, Seung Cheol; Choi, Byung Ihn

    1995-01-01

    To evaluate the radiologic findings of granulomatous colitis on double contrast barium enema and changes on follow-up studies. Serial double contrast barium enema of six patients with granulomatous colitis confirmed by endoscopic biopsy were reviewed. We analyzed the radiologic findings and their follow-up changes, including aphthous ulcers, lymphoid hyperplasia, deep ulcers, cobble stone appearance, geographic ulcers, asymmetric involvement of ulcers, skip lesions, sinus tract, fistula formation, pseudosacculation, focal stricture, and small bowel involvement. Pretreatment double contrast barium enema findings were aphthous ulcers in five patients, deep ulcer in six, cobble stone appearance in five, longitudinal geographic ulcers in two, fistulas in one, pseudosacculations in two, focal stricture in one, and pseudopolyps in six. Also, anal ulcers were observed in two patients, asymmetric involvement of ulcers in three, skip lesions in four, and small bowel involvement in five in five patients proved to have inactive disease after treatment, aphthous ulcers and deep ulcers disappeared. Geographic ulcers of two patients and anal ulcer of one patients decreased in size or depth. Pseudosacculation in one patient disappeared. Pseudopolyps decreased in two patients, increased in one, and decreased after increase in two. One patient whose disease remained active after treatment showed maintenance or increase of ulcers or fistula. And their pseudosacculation or focal stricture unchanged and pseudopolyps decreased. The major radiologic findings of chronic granulomatous colitis on double contrast barium enema are aphthous ulcer, deep ulcer, cobble stone appearance, discontinuity of the lesion and coexistence of ulcers and pseudopolyps. And, double contrast barium enema is good follow-up modality because its findings correlate with clinical course of the granulomatous colitis after treatment

  10. Dissociative absorption: An empirically unique, clinically relevant, dissociative factor.

    Science.gov (United States)

    Soffer-Dudek, Nirit; Lassri, Dana; Soffer-Dudek, Nir; Shahar, Golan

    2015-11-01

    Research of dissociative absorption has raised two questions: (a) Is absorption a unique dissociative factor within a three-factor structure, or a part of one general dissociative factor? Even when three factors are found, the specificity of the absorption factor is questionable. (b) Is absorption implicated in psychopathology? Although commonly viewed as "non-clinical" dissociation, absorption was recently hypothesized to be specifically associated with obsessive-compulsive symptoms. To address these questions, we conducted exploratory and confirmatory factor analyses on 679 undergraduates. Analyses supported the three-factor model, and a "purified" absorption scale was extracted from the original inclusive absorption factor. The purified scale predicted several psychopathology scales. As hypothesized, absorption was a stronger predictor of obsessive-compulsive symptoms than of general psychopathology. In addition, absorption was the only dissociative scale that longitudinally predicted obsessive-compulsive symptoms. We conclude that absorption is a unique and clinically relevant dissociative tendency that is particularly meaningful to obsessive-compulsive symptoms. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Assessing the structure and meaningfulness of the dissociative subtype of PTSD.

    Science.gov (United States)

    Ross, Jana; Baník, Gabriel; Dědová, Mária; Mikulášková, Gabriela; Armour, Cherie

    2018-01-01

    Studies conducted in the USA, Canada and Denmark have supported the existence of the dissociative PTSD subtype, characterized primarily by symptoms of depersonalization and derealization. The current study aimed to examine the dissociative PTSD subtype in an Eastern European, predominantly female (83.16%) sample, using an extended set of dissociative symptoms. A latent profile analysis was applied to the PTSD and dissociation data from 689 trauma-exposed university students from Slovakia. Four latent profiles of varying PTSD and dissociation symptomatology were uncovered. They were named non-symptomatic, moderate PTSD, high PTSD and dissociative PTSD. The dissociative PTSD profile showed elevations on depersonalization and derealization, but also the alternative dissociative indicators of gaps in awareness and memory, sensory misperceptions and cognitive and behavioural re-experiencing. The core PTSD symptoms of 'memory impairment' and 'reckless or self-destructive behaviour' were also significantly elevated in the dissociative PTSD profile. Moreover, anxiety and anger predicted membership in the dissociative PTSD profile. The results provide support for the proposal that the dissociative PTSD subtype can be characterized by a variety of dissociative symptoms.

  12. Combined photoelectron, collision-induced dissociation, and computational studies of parent and fragment anions of N-paranitrophenylsulfonylalanine and N-paranitrophenylalanine

    Science.gov (United States)

    Lambert, Jason; Chen, Jing; Buonaugurio, Angela; Bowen, Kit H.; Do-Thanh, Chi-Linh; Wang, Yilin; Best, Michael D.; Compton, R. N.; Sommerfeld, Thomas

    2013-12-01

    After synthesizing the compounds N-paranitrophenylsulfonylalanine (NPNPSA) and N-paranitrophenylalanine (NPNPA), the photoelectron spectrum of the valence anion of N-paranitrophenylsulfonylalanine (NPNPSA)-, was measured and the collision-induced dissociation (CID) pathways of deprotonated N-paranitrophenylsulfonylalanine (NPNPSA-H)- and deprotonated N-paranitrophenylalanine (NPNPA-H)- were determined. Pertinent calculations were conducted to analyze both sets of experimental data. From the valence anion photoelectron spectrum of (NPNPSA)-, the adiabatic electron affinity (AEA) of NPNPSA was determined to be 1.7 ± 0.1 eV, while the vertical detachment energy (VDE) of (NPNPSA)- was found to be 2.3 ± 0.1 eV. Calculations for four low lying conformers of (NPNPSA)- gave AEA values in the range of 1.6-2.1 eV and VDE values in the range of 2.0-2.4 eV. These calculations are in very good agreement with the experimental values. While the NPNPA anion (NPNPSA)- was not observed experimentally it was studied computationally. The six low lying (NPNPSA)- conformers were identified and calculated to have AEA values in the range of 0.7-1.2 eV and VDE values in the range of 0.9-1.6 eV. CID was used to study the fragmentation patterns of deprotonated NPNPA and deprotonated NPNPSA. Based on the CID data and calculations, the excess charge was located on the delocalized π-orbitals of the nitrobenzene moiety. This is made evident by the fact that the dominant fragments all contained the nitrobenzene moiety even though the parent anions used for the CID study were formed via deprotonation of the carboxylic acid. The dipole-bound anions of both molecules are studied theoretically using the results of previous studies on nitrobenzene as a reference.

  13. Application of parametric equations of motion to study the laser induced multiphoton dissociation of H2+ in intense laser field.

    Science.gov (United States)

    Kalita, Dhruba J; Rao, Akshay; Rajvanshi, Ishir; Gupta, Ashish K

    2011-06-14

    We have applied parametric equations of motion (PEM) to study photodissociation dynamics of H(2)(+). The resonances are extracted using smooth exterior scaling method. This is the first application of PEM to non-Hermitian Hamiltonian that includes resonances and the continuum. Here, we have studied how the different resonance states behave with respect to the change in field amplitude. The advantage of this method is that one can easily trace the different states that are changing as the field parameter changes.

  14. Neural complexity, dissociation, and schizophrenia

    Czech Academy of Sciences Publication Activity Database

    Bob, P.; Šusta, M.; Chládek, Jan; Glaslová, K.; Fedor-Ferybergh, P.

    2007-01-01

    Roč. 13, č. 10 (2007), HY1-5 ISSN 1234-1010 Institutional research plan: CEZ:AV0Z20650511 Keywords : neural complexity * dissociation * schizophrenia Subject RIV: FH - Neurology Impact factor: 1.607, year: 2007

  15. Analytical and Experimental Study of Recycling Baffled Double-Pass Solar Air Heaters with Attached Fins

    Directory of Open Access Journals (Sweden)

    Chun Sheng Lin

    2013-03-01

    Full Text Available The study of the heat transfer of solar air heaters with a new design using an absorbing plate with fins and baffles, which facilitate the recycling of flowing air, is reported. The mathematical formulation and analytical analysis for such a recyclic baffled double-pass solar air heater were developed theoretically. The performance of the device was studied experimentally as well. The theoretical predicted and experimental results were compared with another design, i.e., a downward-type single-pass solar air heater without recycle and double-pass operations reported in our previous work. Significant improvement in heat-transfer efficiency is achieved with the baffle and fin design due to the recycling heating and the extended heat transfer area. The effects of mass flow rate and recycle ratio on the heat-transfer efficiency enhancement as well as on the power consumption increment are also discussed.

  16. Use of orthogonal field alternational gel electrophoresis (OFAGE) for studying DNA double strand breakage and repair

    International Nuclear Information System (INIS)

    Contopoulou, C.R.; Cook, V.; Mortimer, R.K.

    1987-01-01

    The study of DNA double strand breakage and repair has normally been carried by using neutral sucrose gradient or neutral elution techniques. The authors have applied OFAGE procedures to study x-ray induced double strand breaks and repair. Breakage of chromosomes is seen by a decrease in intensity of individual chromosome bands; as expected, this decrease becomes more pronounced as chromosome size increases. The fragments of broken chromosomes appears as a broad smear in the size range 100 kb to 1000 kb. Following repair, these fragments partially disappear and the chromosomal bands increase in intensity. In four repair deficient mutants, rad51, rad52, rad54, rad55, no increase in chromosomal band intensity was seen. These results have been confirmed by blotting for a specific chromosome

  17. Studies on a Double Poisson-Geometric Insurance Risk Model with Interference

    Directory of Open Access Journals (Sweden)

    Yujuan Huang

    2013-01-01

    Full Text Available This paper mainly studies a generalized double Poisson-Geometric insurance risk model. By martingale and stopping time approach, we obtain adjustment coefficient equation, the Lundberg inequality, and the formula for the ruin probability. Also the Laplace transformation of the time when the surplus reaches a given level for the first time is discussed, and the expectation and its variance are obtained. Finally, we give the numerical examples.

  18. Preliminary results from a study of the double beta decay of 150Nd

    International Nuclear Information System (INIS)

    Perillo, I.M.C.; Chan, Y.D.; Hurley, D.; Lesko, K.T.; McDonald, R.J.; Moorhead, M.E.; Norman, E.B.; Smith, A.R.; Stokstad, R.G.

    1996-01-01

    We report the preliminary results from a study of the double beta decay of 150 Nd to the first 0 + excited state of 150 Sm. Our data consists of 50 days of counting 5 kg of natural Nd 2 O 3 at the LBNL-Oroville low background facility. The deduced lower limit for the half life of this decay mode is 4.9.10 19 years. (orig.)

  19. Effect of the surface charge discretization on electric double layers. A Monte Carlo simulation study

    OpenAIRE

    Madurga Díez, Sergio; Martín-Molina, Alberto; Vilaseca i Font, Eudald; Mas i Pujadas, Francesc; Quesada-Pérez, Manuel

    2007-01-01

    The structure of the electric double layer in contact with discrete and continuously charged planar surfaces is studied within the framework of the primitive model through Monte Carlo simulations. Three different discretization models are considered together with the case of uniform distribution. The effect of discreteness is analyzed in terms of charge density profiles. For point surface groups,a complete equivalence with the situation of uniformly distributed charge is found if profiles are...

  20. Atrioventricular Dissociation after Electroconvulsive Therapy

    Directory of Open Access Journals (Sweden)

    Siegfried William Yu

    2011-01-01

    Full Text Available Electroconvulsive therapy (ECT is increasingly used as a treatment for psychiatric disorders. Cardiac effects are the principal cause of medical complications in these patients. We report a case of atrioventricular (AV dissociation that occurred after ECT that was treated with pacemaker implantation. The mechanisms contributing to the onset of AV dissociation in this patient, and the management and rationale for device therapy, in light of the most recent guidelines, are reviewed.

  1. Sub-dissociative dose intranasal ketamine for limb injury pain in children in the emergency department: a pilot study.

    Science.gov (United States)

    Yeaman, Fiona; Oakley, Ed; Meek, Robert; Graudins, Andis

    2013-04-01

    The present study aims to conduct a pilot study examining the effectiveness of intranasal (IN) ketamine as an analgesic for children in the ED. The present study used an observational study on a convenience sample of paediatric ED patients aged 3-13 years, with moderate to severe (≥6/10) pain from isolated limb injury. IN ketamine was administered at enrolment, with a supplementary dose after 15 min, if required. Primary outcome was change in median pain rating at 30 min. Secondary outcomes included change in median pain rating at 60 min, patient/parent satisfaction, need for additional analgesia and adverse events being reported. For the 28 children included in the primary analysis, median age was 9 years (interquartile range [IQR] 6-10). Twenty-three (82.1%) were male. Eighteen (64%) received only one dose of IN ketamine (mean dose 0.84 mg/kg), whereas 10 (36%) required a second dose at 15 min (mean for second dose 0.54 mg/kg). The total mean dose for all patients was 1.0 mg/kg (95% CI: 0.92-1.14). The median pain rating decreased from 74.5 mm (IQR 60-85) to 30 mm (IQR 12-51.5) at 30 min (P pain rating was 25 mm (IQR 4-44). Twenty (83%) subjects were satisfied with their analgesia. Eight (33%) were given additional opioid analgesia and the 28 reported adverse events were all transient and mild. In this population, an average dose of 1.0 mg/kg IN ketamine provided adequate analgesia by 30 min for most patients. © 2013 The Authors. EMA © 2013 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

  2. The Dissociative Subtype of Post-traumatic Stress Disorder: Research Update on Clinical and Neurobiological Features.

    Science.gov (United States)

    van Huijstee, Jytte; Vermetten, Eric

    2017-10-21

    Recently, a dissociative subtype of post-traumatic stress disorder (PTSD) has been included in the DSM-5. This review focuses on the clinical and neurobiological features that distinguish the dissociative subtype of PTSD from non-dissociative PTSD. Clinically, the dissociative subtype of PTSD is associated with high PTSD severity, predominance of derealization and depersonalization symptoms, a more significant history of early life trauma, and higher levels of comorbid psychiatric disorders. Furthermore, PTSD patients with dissociative symptoms exhibit different psychophysiological and neural responses to the recall of traumatic memories. While individuals with non-dissociative PTSD exhibit an increased heart rate, decreased activation of prefrontal regions, and increased activation of the amygdala in response to traumatic reminders, individuals with the dissociative subtype of PTSD show an opposite pattern. It has been proposed that dissociation is a regulatory strategy to restrain extreme arousal in PTSD through hyperinhibition of limbic regions. In this research update, promises and pitfalls in current research studies on the dissociative subtype of PTSD are listed. Inclusion of the dissociative subtype of PTSD in the DSM-5 stimulates research on the prevalence, symptomatology, and neurobiology of the dissociative subtype of PTSD and poses a challenge to improve treatment outcome in PTSD patients with dissociative symptoms.

  3. Double labeling autoradiography. Cell kinetic studies with 3H- and 14C-thymidine

    International Nuclear Information System (INIS)

    Schultze, B.

    1981-01-01

    Examples of the multiple applicability of the double labeling method with 3 H- and 14 C-TdR are demonstrated. Double labeling with 3 H- and 14 C-TdR makes it possible to determine the cycle and its phases with high precision by modifying the usual percent labeled mitoses method with a single injection of 3 H-TdR. In addition, data is provided on the variances of the transit times through the cycle phases. For example, in the case of the jejunal crypt cells of the mouse, the transit times through successive cycle phases are uncorrelated. In the case of glial cells the double labeling method provides cell kinetic parameters despite the paucity of proliferating glial cells. In the adult untreated animal, glial cell mitoses are so rare that the percent labeled mitoses method can not be utilized. However, the S-phase duration can be measured by double labeling and the cycle time can be determined by the so-called method of labeled S phases. With the latter method the passage through the S phase of the 3 H-TdR-labeled S phase cells can be registered by injecting 14 C-TdR at different time intervals following 3 H-TdR application. In this way an S-phase duration of about 10 hr and a cycle time of about 20 hr was found for glial cells in the adult untreated mouse. An exchange of glial cells between the growth fraction and the nongrowth fraction has also been shown by double labeling. A quite different application of the double labeling method with 3H- and 14 C-TdR is the in vivo study of the cell cycle phase-specific effect of drugs used in chemotherapy of tumors. The effect of vincristine on these cells has been studied. Vincristine affects cells in S and G2 in such a manner that they are arrested during the next metaphase and subsequently become necrotic. It has no effect on G1 cells

  4. Dissociative disorders in DSM-5.

    Science.gov (United States)

    Spiegel, David; Lewis-Fernández, Roberto; Lanius, Ruth; Vermetten, Eric; Simeon, Daphne; Friedman, Matthew

    2013-01-01

    The rationale, research literature, and proposed changes to the dissociative disorders and conversion disorder in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) are presented. Dissociative identity disorder will include reference to possession as well as identity fragmentation, to make the disorder more applicable to culturally diverse situations. Dissociative amnesia will include dissociative fugue as a subtype, since fugue is a rare disorder that always involves amnesia but does not always include confused wandering or loss of personality identity. Depersonalization disorder will include derealization as well, since the two often co-occur. A dissociative subtype of posttraumatic stress disorder (PTSD), defined by the presence of depersonalization or derealization in addition to other PTSD symptoms, is being recommended, based upon new epidemiological and neuroimaging evidence linking it to an early life history of adversity and a combination of frontal activation and limbic inhibition. Conversion disorder (functional neurological symptom disorder) will likely remain with the somatic symptom disorders, despite considerable dissociative comorbidity.

  5. Photo induced dissociation of amino acids free from thermal degradation effects: A case study applied to DL-Valine

    International Nuclear Information System (INIS)

    Silva, Á. Miranda da; Mocellin, A.; Farrokhpour, H.; Mundim, M.S.P.; Brito, A. Naves de

    2013-01-01

    We present a careful study of the thermal degradation effects in the mass spectrum of DL-Valine using a quadrupole mass spectrometer and a time of flight – mass spectrometer. This allows setting the temperature of 95 ± 10 °C as threshold for the sublimation of our solid sample. Based on the assignments for each ionic fragment detected, it is possible to separate the mass peaks in groups, explaining what are the principal bond breaks involved in the specific ionic yield, whose procedure can be extended to other amino acids

  6. Photo induced dissociation of amino acids free from thermal degradation effects: A case study applied to DL-Valine

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Á. Miranda da; Mocellin, A. [Instituto, Universidade de Brasília, Box 04455, 70919-970 Brasília-DF (Brazil); Farrokhpour, H. [Chemistry Department, Isfahan University of Technology, 84156-83111 Isfahan (Iran, Islamic Republic of); Mundim, M.S.P. [Instituto, Universidade de Brasília, Box 04455, 70919-970 Brasília-DF (Brazil); Brito, A. Naves de, E-mail: arnaldo.naves@gmail.com [Instituto de Física “Gleb Wataghin”, Universidade Estadual de Campinas, 13083-859 Campinas, SP (Brazil)

    2013-08-15

    We present a careful study of the thermal degradation effects in the mass spectrum of DL-Valine using a quadrupole mass spectrometer and a time of flight – mass spectrometer. This allows setting the temperature of 95 ± 10 °C as threshold for the sublimation of our solid sample. Based on the assignments for each ionic fragment detected, it is possible to separate the mass peaks in groups, explaining what are the principal bond breaks involved in the specific ionic yield, whose procedure can be extended to other amino acids.

  7. First Principles Study of Electronic and Magnetic Structures in Double Perovskites

    Science.gov (United States)

    Ball, Molly

    At present, electronic devices are reaching their storage and processing limit causing a major push to find materials that can be used in the next generation of devices. Double perovskites with A2BB'O 6 stoichiometry form one of the leading classes of materials currently being studied as a potential candidate because of their extremely wide range and tunability of functional properties, along with economic and highly scalable synthesis routes. Having a thorough understanding of their electronic and magnetic structure and their dependence on composition and local structure is the basis for targeted development of novel and optimized double perovskites. While the body of knowledge and rules within the field of materials chemistry has enabled many previous discoveries, recent developments within density functional theory (DFT) allow by now a rather realistic description of the electronic and magnetic properties of materials and especially identification of their origin from geometry and orbital structure. This thesis details computational work based on DFT within several collaborative studies to better understand the electronic and magnetic properties of double perovskites and related materials that show promise for future use in multifunctional devices. First, we will begin with a general introduction to the double perovskite structure, their properties, and the computational methods used to study them. In the next section, we will look at the case of the antiferromagnetic, insulating double perovskite Sr2CoOsO6, where measurements showed that the transition metal ions in the two sublattices undergo magnetic ordering independently of each other, indicating weak magnetic short-range coupling and a dominance of longer-range interactions, which has previously not been observed. Here, we performed DFT calculations to extract the exchange strengths between the ions and explain this unique dominance of the long-range interactions. Then, we will look at studies done on thin

  8. A comparative theoretical study of exciton-dissociation and charge-recombination processes in oligothiophene/fullerene and oligothiophene/perylenediimide complexes for organic solar cells

    KAUST Repository

    Yi, Yuanping; Coropceanu, Veaceslav; Bré das, Jean-Luc

    2011-01-01

    ) is faster than that in the fullerene-based devices and (ii) in most cases, can compete with the dissociation of the charge-transfer state into mobile charge carriers. This faster charge-recombination process is consistent with the lower performance observed

  9. Density functional theory study of the adsorption and dissociation of O{sub 2} on CuO(1 1 1) surface

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Shujuan, E-mail: sunshujuan@hebut.edu.cn [School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130 (China); Li, Chunyu [Science and Technology Innovation Center, Datang Technologies Industry Group Company Limited, Beijing (China); Zhang, Dongsheng [School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130 (China); Wang, Yanji, E-mail: yjwang@hebut.edu.cn [School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130 (China)

    2015-04-01

    Highlights: • The dissociation mechanisms of O{sub 2} on the CuO(1 1 1) surface have been obtained. • The energy barriers and reaction energies are calculated. • The presence of oxygen vacancy can obviously improve the catalytic activity of CuO. - Abstract: Density functional theory (DFT) have been performed to investigate the adsorption and dissociation of O{sub 2} on the perfect and oxygen-deficient CuO(1 1 1) surfaces. The calculated results indicate that the bridge site of two Cu{sub sub} atoms is the most favorable site for O adsorption on the perfect CuO(1 1 1) surface. But on the oxygen-deficient CuO(1 1 1) surface, the O atom adsorbed on O{sub vacancy} site after optimization. On the perfect and oxygen-deficient CuO(1 1 1) surfaces, the O{sub 2} are all paralleling to the surface after optimization. Possible dissociation pathways of molecularly adsorbed O{sub 2} on the two surfaces are identified. The calculated results suggest that the presence of oxygen vacancy exhibits a strong chemical reactivity towards the dissociation of O{sub 2} and can obviously improve the catalytic activity of CuO.

  10. A DFT Study of R-X Bond Dissociation Enthalpies of Relevance to the Initiation Process of Atom Transfer Radical Polymerization

    DEFF Research Database (Denmark)

    Gillies, Malcolm Bjørn; Matyjaszewski, Krzysztof; Norrby, Per-Ola

    2003-01-01

    DFT calculations at the B3P86/6-31G** level have been carried out to derive the bond dissociation energies (BDE) and free energies for a number of R-X systems (X ) Cl, Br, I, N3, and S2-CNMe2) that have been or can potentially be used as initiators for atom transfer radical polymerization (ATRP...

  11. Low-energy electron-induced dissociation in condensed-phase L-cysteine II: a comparative study on anion desorption from chemisorbed and physisorbed films

    International Nuclear Information System (INIS)

    Alizadeh, E.; Rowntree, P.A.; Massey, S.; Sanche, L.

    2016-01-01

    In recent years it has become apparent that dissociative attachment of low energy electrons (DEA) is important for the description of radiation damage to biologically relevant molecules and living cells. Due to its multifunctional structure, cysteine is becoming an ideal model molecule for investigating the complex interactions of proteins with metallic surfaces such as gold nanoparticles. We report herein the results of low-energy electron induced degradation of L-cysteine films, chemisorbed on a gold substrate via the thiol group or physisorbed into a clean gold surface. The data were recorded under ultra-high vacuum conditions at room temperature. Anion yields desorbed from these films by the impact of 0.5 to 19 eV electrons provide clear evidence of the efficient decomposition of this amino acid via dissociative electron attachment (i.e., from dissociation of intermediate transient anions located between 5 and 14 eV). The peaks in the desorbed-anion yield functions, associated with DEA, are superimposed on a continuously rising signal attributed to dipolar dissociation. Similar to the results previously observed from physisorbed films, light anionic species, with masses lower than 35 amu, have been detected. In addition, we measured for first time fragments at 14 amu (CH_2"-) and 15 amu (CH_3"-) desorbing from physisorbed films, as well as heavier fragments of mass 45 and 46 amu desorbing from chemisorbed films

  12. High psychiatric comorbidity in adolescents with dissociative disorders.

    Science.gov (United States)

    Bozkurt, Hasan; Duzman Mutluer, Tuba; Kose, Cigdem; Zoroglu, Salih

    2015-06-01

    The aim of this study was to evaluate psychiatric comorbidity rates and patterns in a sample of clinically referred adolescents diagnosed with dissociative disorders (DD) by using a structured interview. All participants completed a comprehensive test battery, which consisted of a questionnaire for sociodemographic data and clinical history, Child Posttraumatic Stress Reaction Index, Childhood Abuse and Neglect Questionnaire and the Adolescent Dissociative Experiences Scale. Diagnosis was made by the Structured Clinical Interview for DSM-IV Dissociative Disorders. Psychiatric comorbidity was assessed using the Schedule for Affective Disorders and Schizophrenia for School Age Children - Present and Lifetime Version. A total of 25 adolescent subjects aged 12-18 years participated in the study. Ten adolescents were diagnosed as having dissociative identity disorder and 15 of them were diagnosed as having dissociative disorder-not otherwise specified based on the Structured Clinical Interview for DSM-IV Dissociative Disorders findings. Adolescents with dissociative identity disorder were found to have higher scores on the Adolescent Dissociative Experiences Scale and Child Posttraumatic Stress Reaction Index than the dissociative disorder-not otherwise specified group. Sexual and physical abuses were also found to be among the main traumatic events. Incest was reported in six cases of the study sample. All subjects had at least one comorbid psychiatric disorder. The most common psychiatric diagnoses were major depressive disorder (n = 25; 100%) and post-traumatic stress disorder (n = 22; 88%). High psychiatric comorbidity rates were found in adolescents diagnosed with DD. A prevalent history of abuse and traumatic events was represented. Clinicians should be aware of the impacts of DD on adolescents' mental health. © 2014 The Authors. Psychiatry and Clinical Neurosciences © 2014 Japanese Society of Psychiatry and Neurology.

  13. Hybrid-bubble-chamber study of nucleon diffractive dissociation in 14-GeV/c π+-p collisions

    International Nuclear Information System (INIS)

    Chadwick, G.B.; Carroll, J.T.; Chaloupka, V.; Ballam, J.; Bouchez, J.; Herquet, P.; Linglin, D.; Moffeit, K.C.; Stevens, R.; Davidson, V.; Firestone, A.; Nagy, F.; Peck, C.; Rosenfeld, L.; Ely, R.; Grether, D.; Oddone, P.

    1978-01-01

    Two experiments to study the low-mass diffractive enhancement recoiling against a fast forward pion from π + p and π - p collisions at 14 GeV/c are described. Photographs of the SLAC 40-in. hydrogen bubble chamber were triggered by a downstream spectrometer when the missing mass, calculated on-line, was above 1.1 GeV. Evidence for a nonresonant mass peak at 1.35 GeV is presented, as well as for production of resonances at about 1.5 and 1.68 GeV. The data are presented as distributions in mass and momentum transfer, as well as moments and isocline plots of the decay angular distributions. Model-independent features are emphasized

  14. Improved circadian sleep-wake cycle in infants fed a day/night dissociated formula milk.

    Science.gov (United States)

    Cubero, J; Narciso, D; Aparicio, S; Garau, C; Valero, V; Rivero, M; Esteban, S; Rial, R; Rodríguez, A B; Barriga, C

    2006-06-01

    On the basis of the circadian nutritional variations present in breast milk, and of the implications for the sleep/wake cycle of the nutrients present in infant formula milks, we designed a formula milk nutritionally dissociated into a Day/Night composition. The goal was to improve the bottle-fed infant's sleep/wake circadian rhythm. A total of 21 infants aged 4-20 weeks with sleeping difficulties were enrolled in the three-week duration study. The sleep analysis was performed using an actimeter (Actiwatch) placed on an ankle of each infant to uninterruptedly record movements during the three weeks. The dissociated Day milk, designed to be administered from 06:00 to 18:00, contained low levels of tryptophan (1.5g/100g protein) and carbohydrates, high levels of proteins, and the nucleotides Cytidine 5 monophosphate, Guanosine 5 monophosphate and Inosine 5 monophosphate. The dissociated Night milk, designed to be administered from 18.00 to 06.00, contained high levels of tryptophan (3.4g/100g protein) and carbohydrates, low levels of protein, and the nucleotides Adenosine 5 monophosphate and Uridine 5 monophosphate. Three different milk-feeding experiments were performed in a double-blind procedure covering three weeks. In week 1 (control), the infants received both by day and by night a standard formula milk; in week 2 (inverse control), they received the dissociated milk inversely (Night/Day instead of Day/Night); and in week 3, they received the Day/Night dissociated formula concordant with the formula design. When the infants were receiving the Day/Night dissociated milk in concordance with their environment, they showed improvement in all the nocturnal sleep parameters analyzed: total hours of sleep, sleep efficiency, minutes of nocturnal immobility, nocturnal awakenings, and sleep latency. In conclusion, the use of a chronobiologically adjusted infant formula milk seems to be effective in improving the consolidation of the circadian sleep/wake cycle in bottle

  15. Signal and background studies for the search of neutrinoless double beta decay in GERDA

    International Nuclear Information System (INIS)

    Agostini, Matteo

    2013-01-01

    The GERDA experiment searches for the neutrinoless double beta decay in Ge-76, by operating bare HPGe detectors in ultra-pure liquid Ar. This dissertation presents a first decomposition of the background measured in the current data-taking phase. The background at the energy of interest was found to be dominated by 214 Bi, 208 Tl and 42 K gamma-rays, with secondary contributions from 42 K and 214 Bi beta-rays, and 210 Po alpha-rays. For the forthcoming upgrade of the apparatus, a new HPGe detector design (BEGe) has been studied, with focus on its capability of suppressing the identified backgrounds through pulse shape analysis. This included the development of a comprehensive modeling of the detectors and the experimental characterization of their response to surface interactions. The achieved results show that GERDA can improve the present limit on the neutrinoless double beta decay half-life by an order of magnitude.

  16. Theoretical study of the mechanism of formation of a chemical bond between two ions: A+ and B+. Application to CO++. Interpretation of N2O++ photo-dissociation mechanisms

    International Nuclear Information System (INIS)

    Levasseur, Nathalie

    1989-01-01

    This research thesis reports the theoretical study of the mechanism of formation of a chemical bond between two positively charged species, within the frame of the valence-bond theory and in the CO model case. The analysis in terms of orthogonal and non orthogonal orbitals leads to two very different interpretations, and allows potential curves of doubly charged diatomic ions to be simply explained, the generally evoked model to be put into question again, and a predictive model to be developed. The theoretical determination of N 2 O potential energy surfaces and of the first states of N 2 O ++ ( 3 Σ - , 1 Δ, 1 Σ + et 3 Π) allowed experimental results of N 2 O ++ photo-dissociation to be at least qualitatively understood and interpreted. Moreover, the study of electronic configurations involved in dissociation, showed that the model elaborated for a diatomic molecule is also valid for a triatomic system [fr

  17. Reaction mechanism and nuclear correlations study by low energy pion double charge exchange

    International Nuclear Information System (INIS)

    Weinfeld, Z.

    1993-06-01

    In pion double-charge-exchange (DCX) reactions, a positive (negative) pion is incident on a nucleus and a negative (positive) pion emerges. These reactions are of fundamental interest since the process must involve at least two nucleons in order to conserve charge. Although two nucleon processes are present in many reactions they are usually masked by the dominant single nucleon processes. DCX is unique in that respect since it is a two nucleon process in lowest order and thus may be sensitive to two-nucleon correlations. Measurements of low energy pion double-charge-exchange reactions to the double-isobaric-analog-state (DIAS) and ground-state (GS) of the residual nucleus provide new means for studying nucleon-nucleon correlations in nuclei. At low energies (T π 7/2 shell at energies ranging from 25 to 65 MeV. Cross sections were measured on 42,44,48 Ca, 46,50 Ti and 54 Fe. The calcium isotopes make a good set of nuclei on which to study the effects of correlations in DCX reactions

  18. Evaluation of magnocellular pathway abnormalities in schizophrenia: a frequency doubling technology study and clinical implications

    Directory of Open Access Journals (Sweden)

    Fabiana Benites Vaz de Lima

    2013-04-01

    Full Text Available BACKGROUND: Visual processing deficits have been reported for patients with schizophrenia. Previous studies demonstrated differences in early-stage processing of schizophrenics, although the nature, extent, and localization of the disturbance are unknown. The magnocellular and parvocellular visual pathways are associated with transient and sustained channels, but their respective contributions to schizophrenia-related visual deficits remains controversial. PURPOSE: The aim of this study was to evaluate magnocellular dysfunction in schizophrenia using frequency doubling technology. METHODS: Thirty-one patients with schizophrenia and 34 healthy volunteers were examined. Frequency doubling technology testing was performed in one session, consisting of a 15-minute screening strategy followed by the C-20 program for frequency doubling technology. RESULTS: Schizophrenic patients showed lower global mean sensitivity (30,97 ± 2,25 dB compared with controls (32,17 ± 3,08 dB, p<0.009. Although there was no difference in the delta sensitivity of hemispheres, there was a difference in sensitivity analysis of the fibers crossing the optic chiasm, with lower mean sensitivity in the patient group (28,80 dB versus controls (30,66 dB. The difference was higher in fibers that do not cross the optic chiasm, with lower mean sensitivity in patients (27,61 dB versus controls (30,26 dB, p<0.005. CONCLUSIONS: Our results suggest that there are differences between global sensitivity and fiber sensitivity measured by frequency doubling technology. The different sensitivity of fibers that do not cross the optic chiasm is consistent with most current etiological hypotheses for schizophrenia. The decreased sensitivity responses in the optic radiations may significantly contribute to research assessing early-stage visual processing deficits for patients with schizophrenia.

  19. Trauma-Related Dissociation Is Linked With Maladaptive Personality Functioning

    Directory of Open Access Journals (Sweden)

    Antonella Granieri

    2018-05-01

    Full Text Available Background: Extensive research has demonstrated the positive associations among the exposure to traumatic experiences, the levels of dissociation, and the severity of psychiatric symptoms in adults. However, it has been hypothesized in clinical literature that an excessive activation of the dissociative processes following multiple traumatic experiences may jeopardize the psychological and behavioral functioning of the individuals, fostering higher levels of maladaptive personality functioning.Methods: The study involved 322 adult volunteers from Italy. Participants completed measures on traumatic experiences, dissociation, and maladaptive personality traits.Results: The number of traumatic experiences reported by participants were positively associated with dissociation scores and maladaptive personality scores. Mediation analyses showed that dissociation acted as a partial mediator in the relationship between traumatic experiences and overall maladaptive personality functioning. Regression curve analyses showed that the positive association between maladaptive personality functioning and dissociation was stronger among participants with higher exposure to traumatic experiences.Conclusion: Exposure to multiple traumatic experiences may increase the risk for an excessive activation of the dissociative processes, which in turn may generate severe impairments in multiple domains of personality functioning.

  20. Study of the F sup(+)sub(2) centers stabilization process in LiF:OH sup(-) crystals and spectroscopy of the OH sup(-) dissociation

    International Nuclear Information System (INIS)

    Courrol, L.C.

    1990-01-01

    We studied the process of stabilization of the F sup(+) sub(2) centers in irradiated LiF:OH sup(-) single crystals. A consistent investigation of the wide number of defects produced by the radiation damage in the lattice allowed us to improve the experimental conditions to increase the final number of stabilized F sup(+) sub(2). It has been established the model for the F sup(+) sub(2):O sup(2-) formation in LiF:OH sup(-) irradiated based on a statistical distribution of the defects produced during the electron irradiation at 230K. These stabilized centers are formed during the thermal diffusion of the anionic vacancies in competition with the isolated F sup(+) sub(2) centers. A critical distance of thirteen lattice parameters determined for a vacancy suggested that the O sup(2-) -α dipole is the precursor entity for the F sup(+) sub(2):O sup(2-) creation. A further increasing of the F sup(+) sub(2) stabilized concentration was obtained after the e sup(-) - irradiation and the vacancy generation process by irradiating the samples at 77K with a small dose of gamma rays. The same net effect was seen after the e sup(-) - irradiation by keeping the samples at room temperature for at least 6 months as a consequence of the thermal activated diffusion of the remaining O sup(2-) -α dipoles and reaction with F centers. The sub-products of the OH sup(-) dissociation induced by the high energy irradiation were identified by spectroscopical analysis. A new defect was identified as a F sub(z) center containing a water molecule. Its luminescence properties and stability has been determined. Future investigations and some implications from the model has been discussed. (author)

  1. A Study of Free-Piston Double-Diaphragm Drivers for Expansion Tubes. Report 1

    Science.gov (United States)

    Kendall, M. A.

    1997-01-01

    In recent years the free-piston double-diaphragm driver has been used to increase the performance of the XI pilot expansion tube to super-orbital test conditions. However, the actual performance of the double-diaphragm driver was found to be considerably less than ideal. An experimental study of the double-diaphragm driver was carried out on the XI facility over a range of conditions with the objective of determining the effect of. heat losses; and the non-ideal rupture of the 'light' secondary diaphragm on the driver performance. The disparity between the theoretical and measured performance envelope are highlighted. A viscous limit for the experiments vas established. Heat transfer behind the primary shock is shown to be the mechanism behind this limit Incident, reflected and transmitted shock trajectories for the secondary diaphragm were experimentally determined and compared with computed trajectories from a one-dimensional diaphragm inertia model. It was found that the diaphragm did influence the unsteady expansion. A good agreement between experimental and computed shock trajectories was obtained using a diaphragm inertia model assuming that the diaphragm mass became negligible 3 microns after shock impact.

  2. Wind tunnel study of natural ventilation of building integrated photovoltaics double skin façade

    Directory of Open Access Journals (Sweden)

    Hudişteanu Sebastian Valeriu

    2018-01-01

    Full Text Available The paper presents a wind tunnel experimental analysis of a small-scale building model (1:30. The objective of the study is to determine the wind influence on the ventilation of a double skin façade channel (DSF and the cooling effect over integrated photovoltaic panels. The tests were achieved by conceiving and implementation of an experimental program using a wind tunnel with atmospheric boundary layer. The effect of the wind over the ventilation of the horizontal channels of double skin façades is evaluated for different incident velocities. The results are generalized for the average steady state values of the velocities analysed. The experimental results put in evidence the correlation between the reference wind velocity and the dynamics of the air movement inside the double skin façade. These values are used to determine the convective heat transfer and the cooling effect of the air streams inside the channel upon the integrated photovoltaic panels. The decrease of the photovoltaic panels temperature determines a raise of 11% in efficiency and power generated.

  3. Clinical study of double dose of valsartan combined with tacrolimus in treatment of diabetic nephropathy.

    Science.gov (United States)

    Jin, H; Zhang, H-N; Hou, X-L; Zhang, B; Wu, J; Zhang, H-B

    2016-01-01

    To investigate the clinical effect of double dose of valsartan combined with tacrolimus in the treatment of diabetic nephropathy (DN). HA total of 86 cases diagnosed with DN were selected from October 2013 to October 2014 in Zaozhuang Municipal Hospital, China. The study was approved by our hospital Ethics Committee and written consent was obtained from patients and their family members. Patients were randomly divided into three groups according to the sequence of admission, group A (conventional dose of valsartan group, n = 28 cases), group B (double dose of valsartan group, n = 29 cases) and group C (double dose of valsartan combined with tacrolimus group, n = 29). Clinical effects were compared by analyzing the renal function tests after 8 weeks. 24h urine protein, serum creatinine level of patients in group B and group C were significantly lower than that of group A. Those in group C was much lower. The glomerular filtration rates were significantly higher for group B and C than that of group A, and those in group C were much higher. The difference is statistically significant (p valsartan combined with tacrolimus treatment of DN patients can improve clinical symptoms, reducing inflammation, inhibiting or even reversing the interstitial fibrosis, which will improve the curative effect and reduce the recurrence, as to provide a new theoretical basis for the clinical treatment of the disease.

  4. Wind tunnel study of natural ventilation of building integrated photovoltaics double skin façade

    Science.gov (United States)

    Hudişteanu, Sebastian Valeriu; Popovici, Cătălin George; Cherecheş, Nelu-Cristian

    2018-02-01

    The paper presents a wind tunnel experimental analysis of a small-scale building model (1:30). The objective of the study is to determine the wind influence on the ventilation of a double skin façade channel (DSF) and the cooling effect over integrated photovoltaic panels. The tests were achieved by conceiving and implementation of an experimental program using a wind tunnel with atmospheric boundary layer. The effect of the wind over the ventilation of the horizontal channels of double skin façades is evaluated for different incident velocities. The results are generalized for the average steady state values of the velocities analysed. The experimental results put in evidence the correlation between the reference wind velocity and the dynamics of the air movement inside the double skin façade. These values are used to determine the convective heat transfer and the cooling effect of the air streams inside the channel upon the integrated photovoltaic panels. The decrease of the photovoltaic panels temperature determines a raise of 11% in efficiency and power generated.

  5. Double product and end-organ damage in African and Caucasian men: the SABPA study.

    Science.gov (United States)

    Schultz, A J; Schutte, A E; Schutte, R

    2013-08-10

    Increasing urbanisation in sub-Saharan African countries is causing a rapid increase in cardiovascular disease. Evidence suggests that Africans have higher blood pressures and a higher prevalence of hypertension-related cardiovascular morbidity and mortality, compared to Caucasians. We investigated double product (systolic blood pressure × heart rate), a substantial measure of cardiac workload, as a possible cardiovascular risk factor in African and Caucasian men. The study consisted of 101 urbanised African and 101 Caucasian male school teachers. We measured 24h ambulatory blood pressure and the carotid cross-sectional wall area, and determined left ventricular hypertrophy electrocardiographically by means of the Cornell product. Urinary albumin and creatinine were analysed to obtain the albumin-to-creatinine ratio. Africans had higher 24h, daytime and nighttime systolic- and diastolic blood pressure, heart rate and resultant double product compared to the Caucasians. In addition, markers of end-organ damage, albumin-to-creatinine ratio and left ventricular hypertrophy were higher in the Africans while cross-sectional wall area did not differ. In Africans after single partial and multiple regression analysis, 24h systolic blood pressure, but not double product or heart rate, correlated positively with markers of end-organ damage (cross-sectional wall area: β=0.398, P=0.005; left ventricular hypertrophy: β=0.455, Pproduct may not be a good marker of increased cardiovascular risk when compared to systolic blood pressure in African and Caucasian men. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  6. Grammatical category dissociation in multilingual aphasia.

    Science.gov (United States)

    Faroqi-Shah, Yasmeen; Waked, Arifi N

    2010-03-01

    Word retrieval deficits for specific grammatical categories, such as verbs versus nouns, occur as a consequence of brain damage. Such deficits are informative about the nature of lexical organization in the human brain. This study examined retrieval of grammatical categories across three languages in a trilingual person with aphasia who spoke Arabic, French, and English. In order to delineate the nature of word production difficulty, comprehension was tested, and a variety of concomitant lexical-semantic variables were analysed. The patient demonstrated a consistent noun-verb dissociation in picture naming and narrative speech, with severely impaired production of verbs across all three languages. The cross-linguistically similar noun-verb dissociation, coupled with little evidence of semantic impairment, suggests that (a) the patient has a true "nonsemantic" grammatical category specific deficit, and (b) lexical organization in multilingual speakers shares grammatical class information between languages. The findings of this study contribute to our understanding of the architecture of lexical organization in bilinguals.

  7. Investigating the dissociative subtype of posttraumatic stress disorder in a sample of traumatized detained youth.

    Science.gov (United States)

    Bennett, Diana C; Modrowski, Crosby A; Kerig, Patricia K; Chaplo, Shannon D

    2015-09-01

    In this study, we tested the validity of a dissociative subtype in a sample of 225 detained adolescents (142 boys, 83 girls) likely meeting full or partial criteria for posttraumatic stress disorder (PTSD). Competing theories of dissociation pose controversy regarding dissociation as a taxon versus a continuum, and results of the current study contribute to this debate by providing evidence of distinct group differences between those high and low in dissociation. Mixture modeling revealed 2 groups of youth with differing levels of depersonalization/derealization dissociative symptoms. Differences between the 2 groups of youth were investigated regarding trauma exposure and several posttraumatic reactions: posttraumatic stress symptoms (PTSS), emotion dysregulation, and emotional numbing. Compared with youth classified in the low-dissociation group, youth who exhibited high levels of dissociation demonstrated higher levels of total PTSS, posttraumatic symptom clusters of emotional numbing, intrusion, and associated features, as well as reporting more difficulties with emotion dysregulation. To test theory regarding the factors that increase the likelihood of persistent dissociation, bootstrapped regression analyses were performed to examine the possibility of an indirect effect of peritraumatic dissociation. Results consistent with statistical mediation suggested that the presence of peritraumatic dissociation at the time of trauma may contribute to the continuation of dissociative symptoms as a more generalized pattern. The results of the current study have implications for clinical treatment with traumatized youth. (c) 2015 APA, all rights reserved).

  8. Dissociative amnesia in dissociative disorders and borderline personality disorder: self-rating assessment in a college population.

    Science.gov (United States)

    Sar, Vedat; Alioğlu, Firdevs; Akyuz, Gamze; Karabulut, Sercan

    2014-01-01

    Dissociative amnesia (DA) among subjects with a dissociative disorder and/or borderline personality disorder (BPD) recruited from a nonclinical population was examined. The Steinberg Dissociative Amnesia Questionnaire (SDAQ), the Childhood Trauma Questionnaire, and the self-report screening tool of the BPD section of the Structured Clinical Interview for DSM-IV(SCID-BPD) were administered to 1,301 college students. A total of 80 participants who were diagnosed with BPD according to the clinician-administered SCID-BPD and 111 nonborderline controls were evaluated using the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D) by a psychiatrist blind to diagnosis and scale scores. Internal consistency analyses and test-retest evaluations suggested that the SDAQ is a reliable instrument for the population studied. Of the participants, 20.6% reported an SDAQ score of 20 or above and impairment by DA. Those who had both dissociative disorder and BPD (n = 78) had the highest SDAQ scores. Both disorders had significant effects on the SCID-D total and amnesia scores in the variance analysis. On SDAQ scores, however, only BPD had this effect. There was a significant interaction between the 2 disorders for the SCID-D total but not for the SDAQ or SCID-D amnesia scores. BPD represented the severity of dissociation and childhood trauma in this study group. However, in contrast to the dissociative disorders, BPD was characterized by better awareness of DA in self-report. The discrepancies between self-report and clinical interview associated with BPD and dissociative disorders are discussed in the context of betrayal theory (J. J. Freyd, 1994) of BPD and perceptual theory (D. B. Beere, 2009) of dissociative disorders.

  9. [Childhood traumatization, dissociation and nonsuicidal self-injurious behavior in borderline personality disorder].

    Science.gov (United States)

    Merza, Katalin; Harmatta, János; Papp, Gábor; Kuritárné Szabó, Ildikó

    2017-05-01

    Childhood traumatization plays a significant role in the etiology of borderline personality disorder. Studies found a significant association between childhood traumatization, dissociation, and nonsuicidal self-injurious behavior. The aim of our study was to assess dissociation and nonsuicidal self-injury among borderline inpatients and to reveal the association between childhood traumatization, dissociation, and self-injurious behavior. The sample consisted of 80 borderline inpatients and 73 depressed control patients. Childhood traumatization, dissociation and self-injurious behavior were assessed by questionnaires. Borderline patients reported severe and multiplex childhood traumatization. Cumulative trauma score and sexual abuse were the strongest predictors of dissociation. Furthermore, we have found that cumulative trauma score and dissociation were highly predictive of self-injurious behavior. Our results suggest that self-injurious behavior and dissociation in borderline patients can be regarded as indicators of childhood traumatization. Orv Hetil. 2017; 158(19): 740-747.

  10. Study of the Light Emission Process from the Double Chooz Photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, E.; Cerrada, M.; Crespo, J. I.; Gil-Botella, I.; Jimenez, S.; Lopez, M.; Novella, P.; Palomares, C.; Santorelli, R.; Verdugo, A.

    2012-09-13

    In this document we present a study of the light emitted by the base of a Hamamatsu R7081MOD-ASSY photomultiplier (PMT) of the same type used in the Double Chooz experiment. Several characteristic features of the light signal have been found in terms of amplitude, length and pulse shape. Additional investigations on the properties of the epoxy used to cover the photomultiplier base have been carried out. A possible explanation of the light emission process is discussed at the end of the study. (Author) 1 ref.

  11. P300 is attenuated during dissociative episodes.

    Science.gov (United States)

    Kirino, Eiji

    2006-02-01

    The present study examined the pathophysiology of dissociative phenomena using the P300 component of event-related potentials, quantitative electroencephalography (QEEG), and morphology measures of computed tomography scan. Event-related potentials during an auditory oddball paradigm and QEEG in resting state were recorded. Patients exhibited attenuation of P300 amplitudes compared with controls during dissociative episodes, but exhibited recovery to control levels in remission. Patients had a larger Sylvian fissure-brain ratio than did controls. QEEG findings revealed no significant differences between the patients and controls or between episodes and remission in the patient group. Attenuation of the P300 can be interpreted as the result of a negative feedback loop from the medial temporal lobe to the cortex, which decreases the amount of information flow, allocation of attentional resources, and updating of working memory to avoid both excessive long-term memory system activity in medial temporal lobe and resurgence of affect-laden memories.

  12. Critical superheats upon boiling of dissociating liquids

    International Nuclear Information System (INIS)

    Kolykhan, L.I.; Solov'ev, V.N.

    1985-01-01

    The experimental data on critical superheats of dissociating liquids, i.e. nitrogen tetroxide and nitrine are presented (nitrine is the solution of nitrogen oxide in nitrogen tetroxide). The experiments with boiling N 2 O 4 have been carried out in the pressure range 0.1-3.0 MPa and with boiling nitrine within the pressure range 0.2-9.0 MPa. The experiments have revealed an anomalous dependence of critical superheats on pressure P, thus at P>=2.5 MPa the critical superheat values exceed the limiting ones, and at P=4.5 MPa this excess amounts to more than 16 K, essentially exceeding the errors of the experiments. The results for N 2 O 4 critical superheats agree with experimental data of other authors. Complex phenomena observed upon boiling of dissociating liquids require further theoretical and experimental studies

  13. Photon diffractive dissociation in deep inelastic scattering

    International Nuclear Information System (INIS)

    Ryskin, M.G.

    1990-01-01

    The new ep-collider HERA gives us the possibility to study the diffractive dissociation of virtual photon in deep inelastic ep-collision. The process of photon dissociation in deep inelastic scattering is the most direct way to measure the value of triple-pomeron vertex G 3P . It was shown that the value of the correct bare vertex G 3P may more than 4 times exceeds its effective value measuring in the triple-reggeon region and reaches the value of about 40-50% of the elastic pp-pomeron vertex. On the contrary in deep inelastic processes the perpendicular momenta q t of the secondary particles are large enough. Thus in deep inelastic reactions one can measure the absolute value of G 3P vertex in the most direct way and compare its value and q t dependence with the leading log QCD predictions

  14. Cell membrane antigen-antibody complex dissociation by the widely used glycine-HCL method: an unreliable procedure for studying antibody internalization.

    Science.gov (United States)

    Tsaltas, G; Ford, C H

    1993-02-01

    Methods following the process of binding and internalization of antibodies to cell surface antigens have often employed low pH isoosmolar buffers in order to dissociate surface antigen-antibody complexes. One of the most widely used buffers is a 0.05 M glycine-HCL buffer pH 2.8. Since the efficacy of action of this buffer was critical to a series of internalization experiments employing monoclonal antibodies (Mabs) to carcinoembryonic antigen (CEA) expressing cancer cell lines in this laboratory, we tested its performance in a number of different assays. Our results indicate that this buffer only partially dissociates antigen-antibody bonds and therefore can introduce major inaccuracies in internalization experiments.

  15. Dissociation, childhood trauma, and ataque de nervios among Puerto Rican psychiatric outpatients.

    Science.gov (United States)

    Lewis-Fernández, Roberto; Garrido-Castillo, Pedro; Bennasar, Mari Carmen; Parrilla, Elsie M; Laria, Amaro J; Ma, Guoguang; Petkova, Eva

    2002-09-01

    This study examined the relationships of dissociation and childhood trauma with ataque de nervios. Forty Puerto Rican psychiatric outpatients were evaluated for frequency of ataque de nervios, dissociative symptoms, exposure to trauma, and mood and anxiety psychopathology. Blind conditions were maintained across assessments. Data for 29 female patients were analyzed. Among these 29 patients, clinician-rated dissociative symptoms increased with frequency of ataque de nervios. Dissociative Experiences Scale scores and diagnoses of panic disorder and dissociative disorders were also associated with ataque frequency, before corrections were made for multiple comparisons. The rate of childhood trauma was uniformly high among the patients and showed no relationship to dissociative symptoms and disorder or number of ataques. Frequent ataques de nervios may, in part, be a marker for psychiatric disorders characterized by dissociative symptoms. Childhood trauma per se did not account for ataque status in this group of female outpatients.

  16. Dissociation of acetone radical cation (CH3COCH3(+*) --> CH3CO(+) + CH3(*)): an ab initio direct classical trajectory study of the energy dependence of the branching ratio.

    Science.gov (United States)

    Zhou, Jia; Schlegel, H Bernhard

    2008-12-18

    The nonstatistical dissociation of acetone radical cation has been studied by ab initio direct classical trajectory calculations at the MP2/6-31G(d) level of theory. A bond additivity correction has been used to improve the MP2 potential energy surface (BAC-MP2). The energy dependence of the branching ratio, dissociation kinetics, and translational energy distribution for the two types of methyl groups have been investigated using microcanonical ensembles and specific mode excitation. In each case, the dissociation favors the loss of the newly formed methyl group, in agreement with the experiments. For microcanonical ensembles, the branching ratios for methyl loss are calculated to be 1.43, 1.88, 1.70, and 1.50 for 1, 2, 10, and 18 kcal/mol of excess energy, respectively. The energy dependence of the branching ratio is seen more dramatically in the excitation of individual modes involving C-C-O bending. For modes 3 and 6, the branching ratio rises to 1.6 and 1.8-2.3 when 1 or 2 kcal/mol are added, respectively, but falls off when more energy is added. For mode 8, the branching ratio continues to rise monotonically from 1.5 to 2.76 when 1-8 kcal/mol of excess energy are added.

  17. Dissociated cultures of newborn mouse brain

    International Nuclear Information System (INIS)

    Wiesmann, U.N.; Hofmann, K.; Burkhart, T.; Herschkowitz, N.

    1975-01-01

    The metabolism of 35 SO 4 -sulfated lipids and mucopolysaccharides was studied in dissociated brain cell cultures from newborn albino mouse brains. The cultures were maintained under an atmosphere of 40% O 2 and 5% CO 2 in apparent good health up to 30 days. Early morphological examination of the dissociated cells demonstrated an initial partial reaggregation of the cells, which later settled and became confluent bilayered cultures. Cell proliferation measured by DNA and protein determination, morphological differentiation and biochemical differentiation took place in the dissociated brain cell cultures analogous in some respects to the in vivo situation. A timed increase in the synthesis of a myelin precursor, cerebroside 35 SO 4 , was observed after 6 to 8 days in culture (DIC). A peak of cerebroside sulfate was evident at 17 DIC. No stable sulfatide was observed at any time. Protein-bound macromolecular 35 SO 4 -MPS was synthetized and secreted from the cells into the culture medium. Maximal synthesis and secretion occurred at 8 DIC. This culture system proves to be a useful model for studying some aspects of differentiation of brain cells under external conditions. (author)

  18. DSM-5's posttraumatic stress disorder with dissociative symptoms: challenges and future directions.

    Science.gov (United States)

    Dorahy, Martin J; van der Hart, Onno

    2015-01-01

    The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, formally recognizes a dissociative subtype of posttraumatic stress disorder (PTSD; PTSD with dissociative symptoms). This nomenclative move will boost empirical and theoretical efforts to further understand the links between dissociation, trauma, and PTSD. This article examines the empirical literature showing that patients with PTSD can be divided into 2 different groups based on their neurobiology, psychological symptom profile, history of exposure to early relational trauma, and depersonalization/derealization symptoms. It then explores the conceptual and empirical challenges of conceiving 1 of these types as reflecting a "dissociative" type of PTSD. First, this classification is based on the presence of a limited subset of dissociative symptoms (i.e., depersonalization, derealization). This sets aside an array of positive and negative psychoform and somatoform dissociative symptoms that may be related to PTSD. Second, empirical evidence suggests heightened dissociation in PTSD compared to many other disorders, indicating that dissociation is relevant to PTSD more broadly rather than simply to the so-called dissociative subtype. This article sets out important issues to be examined in the future study of dissociation in PTSD, which needs to be informed by solid conceptual understandings of dissociation.

  19. Low-energy electron-induced dissociation in condensed-phase L-cysteine II: a comparative study on anion desorption from chemisorbed and physisorbed films

    Science.gov (United States)

    Alizadeh, Elahe; Massey, Sylvain; Sanche, Léon; Rowntree, Paul A.

    2016-04-01

    Due to its multifunctional structure, cysteine is becoming an ideal model molecule for investigating the complex interactions of proteins with metallic surfaces such as gold nanoparticles. We report herein the results of low-energy electron induced degradation of L-cysteine films, chemisorbed on a gold substrate via the thiol group or physisorbed into a clean gold surface. The data were recorded under ultra-high vacuum conditions at room temperature. Anion yields desorbed from these films by the impact of 0.5 to 19 eV electrons provide clear evidence of the efficient decomposition of this amino acid via dissociative electron attachment (i.e., from dissociation of intermediate transient anions located between 5 and 14 eV). The peaks in the desorbed-anion yield functions, associated with DEA, are superimposed on a continuously rising signal attributed to dipolar dissociation. Similar to the results previously observed from physisorbed films, light anionic species, with masses lower than 35 amu, have been detected. In addition, we measured for first time fragments at 14 amu (CH2-) and 15 amu (CH3-) desorbing from physisorbed films, as well as heavier fragments of mass 45 and 46 amu desorbing from chemisorbed films. Contribution to the Topical Issue "Low-Energy Interactions related to Atmospheric and Extreme Conditions", edited by S. Ptasinska, M. Smialek-Telega, A. Milosavljevic, B. Sivaraman.

  20. Study on spin filtering and switching action in a double-triangular network chain

    Science.gov (United States)

    Zhang, Yongmei

    2018-04-01

    Spin transport properties of a double-triangular quantum network with local magnetic moment on backbones and magnetic flux penetrating the network plane are studied. Numerical simulation results show that such a quantum network will be a good candidate for spin filter and spin switch. Local dispersion and density of states are considered in the framework of tight-binding approximation. Transmission coefficients are calculated by the method of transfer matrix. Spin transmission is regulated by substrate magnetic moment and magnetic flux piercing those triangles. Experimental realization of such theoretical research will be conducive to designing of new spintronic devices.

  1. Experimental Study on Superfine Sand Concrete Mixed by Double Mixing Technology

    OpenAIRE

    yuqing zhao

    2013-01-01

    Traditional concept thought that medium sand and fine sand can be used to mix concrete, superfine sand can not used to mix concrete. This makes the source of superfine sand limited. With the shortage of medium sand and fine sand, it is imperative to exploit the resource of superfine sand. Superfine sand concrete is mixed by means of Double-doped Technology-ultra-fine fly ash and super plasticizer. Primary factor influencing superfine sand concrete strength is studied by orthogonal test, the o...

  2. Study on Modelling Standardization of Double-fed Wind Turbine and Its Application

    Directory of Open Access Journals (Sweden)

    Li Xiang

    2016-01-01

    Full Text Available Based on the standardized modelling of the International Modelling Team, study on double-fed induction generator (DFIG wind turbine is processed in this paper, aiming at capability of universally and reasonably reflecting key performance related to large scale system analysis. The standardized model proposed is of high degree of structural modularity, easy functional extension and universalization of control strategy and signal. Moreover, it is applicable for wind turbines produced by different manufacturers through model parameter adjustment. The complexity of the model can meet both needs of grid-connected characteristic simulation of wind turbine and large scale power system simulation.

  3. Studying the Relative Positions of the Teeth of Conjugated Wheels in the Double Harmonic Transmission

    Directory of Open Access Journals (Sweden)

    Draghiţa Ianici

    2017-11-01

    Full Text Available The paper presents a detailed study of the gearing processes in the two stages of the double harmonic transmission. To highlight the graphics of the relative motion of the conjugates teeth it was developed an original calculation program, written in Visual Basic. By running the calculation program, the relative successive positions of the conjugate teeth were viewed and the basic parameters of the gearing were established: the angle profile (α, the tooth height (h and the size of the deformation of the flexible toothed wheel (w0.

  4. A variational study of the self-trapped magnetic polaron formation in double-exchange model

    International Nuclear Information System (INIS)

    Liu Tao; Feng Mang; Wang Kelin

    2005-01-01

    We study the formation of self-trapped magnetic polaron (STMP) in an antiferro/ferromagnetic double-exchange model semi-analytically by variational solutions. It is shown that the Jahn-Teller effect is not essential to the STMP formation and the STMP forms in the antiferromagnetic material within the region of the order of the lattice constant. We also confirm that no ground state STMP exists in the ferromagnetic background, but the ground state bound MP could appear due to the impurity potential

  5. Abstract probabilistic CNOT gate model based on double encoding: study of the errors and physical realizability

    Science.gov (United States)

    Gueddana, Amor; Attia, Moez; Chatta, Rihab

    2015-03-01

    In this work, we study the error sources standing behind the non-perfect linear optical quantum components composing a non-deterministic quantum CNOT gate model, which performs the CNOT function with a success probability of 4/27 and uses a double encoding technique to represent photonic qubits at the control and the target. We generalize this model to an abstract probabilistic CNOT version and determine the realizability limits depending on a realistic range of the errors. Finally, we discuss physical constraints allowing the implementation of the Asymmetric Partially Polarizing Beam Splitter (APPBS), which is at the heart of correctly realizing the CNOT function.

  6. "Live high-train low" using normobaric hypoxia: a double-blinded, placebo-controlled study

    DEFF Research Database (Denmark)

    Siebenmann, Christoph; Robach, Paul; Jacobs, Robert A

    2012-01-01

    The combination of living at altitude and training near sea level [live high-train low (LHTL)] may improve performance of endurance athletes. However, to date, no study can rule out a potential placebo effect as at least part of the explanation, especially for performance measures. With the use o...... of a placebo-controlled, double-blinded design, we tested the hypothesis that LHTL-related improvements in endurance performance are mediated through physiological mechanisms and not through a placebo effect. Sixteen endurance cyclists trained for 8 wk at low altitude (...

  7. 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-.

  8. Memories of attachment hamper EEG cortical connectivity in dissociative patients.

    Science.gov (United States)

    Farina, Benedetto; Speranza, Anna Maria; Dittoni, Serena; Gnoni, Valentina; Trentini, Cristina; Vergano, Carola Maggiora; Liotti, Giovanni; Brunetti, Riccardo; Testani, Elisa; Della Marca, Giacomo

    2014-08-01

    In this study, we evaluated cortical connectivity modifications by electroencephalography (EEG) lagged coherence analysis, in subjects with dissociative disorders and in controls, after retrieval of attachment memories. We asked thirteen patients with dissociative disorders and thirteen age- and sex-matched healthy controls to retrieve personal attachment-related autobiographical memories through adult attachment interviews (AAI). EEG was recorded in the closed eyes resting state before and after the AAI. EEG lagged coherence before and after AAI was compared in all subjects. In the control group, memories of attachment promoted a widespread increase in EEG connectivity, in particular in the high-frequency EEG bands. Compared to controls, dissociative patients did not show an increase in EEG connectivity after the AAI. Conclusions: These results shed light on the neurophysiology of the disintegrative effect of retrieval of traumatic attachment memories in dissociative patients.

  9. [Dissociative identity disorder or schizophrenia?].

    Science.gov (United States)

    Tschöke, S; Steinert, T

    2010-01-01

    We present a case of dissociative identity disorder in which Schneiderian first rank symptoms were present besides of various states of consciousness. Thus the diagnosis of schizophrenia had to be considered. Formally, the symptoms met ICD-10 criteria for schizophrenia. However, taking into account the lack of formal thought disorder and of negative symptoms as well as a typical history of severe and prolonged traumatisation, we did not diagnose a co-morbid schizophrenic disorder. There is good evidence for the existence of psychotic symptoms among patients with dissociative disorders. However, in clinical practice this differential diagnosis is rarely considered.

  10. Dissociative symptoms and dissociative disorders comorbidity in obsessive compulsive disorder: Symptom screening, diagnostic tools and reflections on treatment

    OpenAIRE

    Belli, Hasan

    2014-01-01

    Borderline personality disorder, conversion disorder and obsessive compulsive disorder frequently have dissociative symptoms. The literature has demonstrated that the level of dissociation might be correlated with the severity of obsessive compulsive disorder (OCD) and that those not responding to treatment had high dissociative symptoms. The structured clinical interview for DSM-IV dissociative disorders, dissociation questionnaire, somatoform dissociation questionnaire and dissociative expe...

  11. Sensory dissociation in chronic low back pain: Two case reports.

    Science.gov (United States)

    Adamczyk, Wacław M; Luedtke, Kerstin; Saulicz, Oskar; Saulicz, Edward

    2018-08-01

    Patients with chronic low back pain often report that they do not perceive their painful back accurately. Previous studies confirmed that sensory dissociation and/or discrepancy between perceived body image and actual size is one of the specific traits of patients with chronic pain. Current approaches for measuring sensory dissociation are limited to two-point-discrimination or rely on pain drawings not allowing for quantitative analysis. This case study reports the sensory dissociation of two cases with chronic low back pain using a recently published test (point-to-point-test (PTP)) and a newly developed test (two-point-estimation (TPE)). Both patients mislocalized tactile stimuli delivered to the painful location compared to non-painful locations (PTP test). In addition, both patients perceived their painful lumbar region differently from non-painful sites above and below and contralateral to the painful site. TPE data showed two distinct clinical patterns of sensory dissociation: one patient perceived the two-point distance in the painful area as expanded, while the other patient perceived it as shrunk. The latter pattern of sensory dissociation (i.e., pattern shrunk) is likely to respond to sensory training. Whether enlarged patterns of sensory dissociation are more resistant to treatment remains unknown but would explain the low effectiveness of previous studies using sensory training in chronic low back pain populations. Subgrouping patients according to their sensory discrimination pattern could contribute to the choice and effectiveness of the treatment approach.

  12. Double hard scattering without double counting

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, Markus [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Gaunt, Jonathan R. [VU Univ. Amsterdam (Netherlands). NIKHEF Theory Group; Schoenwald, Kay [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2017-02-15

    Double parton scattering in proton-proton collisions includes kinematic regions in which two partons inside a proton originate from the perturbative splitting of a single parton. This leads to a double counting problem between single and double hard scattering. We present a solution to this problem, which allows for the definition of double parton distributions as operator matrix elements in a proton, and which can be used at higher orders in perturbation theory. We show how the evaluation of double hard scattering in this framework can provide a rough estimate for the size of the higher-order contributions to single hard scattering that are affected by double counting. In a numeric study, we identify situations in which these higher-order contributions must be explicitly calculated and included if one wants to attain an accuracy at which double hard scattering becomes relevant, and other situations where such contributions may be neglected.

  13. Double hard scattering without double counting

    International Nuclear Information System (INIS)

    Diehl, Markus; Gaunt, Jonathan R.

    2017-02-01

    Double parton scattering in proton-proton collisions includes kinematic regions in which two partons inside a proton originate from the perturbative splitting of a single parton. This leads to a double counting problem between single and double hard scattering. We present a solution to this problem, which allows for the definition of double parton distributions as operator matrix elements in a proton, and which can be used at higher orders in perturbation theory. We show how the evaluation of double hard scattering in this framework can provide a rough estimate for the size of the higher-order contributions to single hard scattering that are affected by double counting. In a numeric study, we identify situations in which these higher-order contributions must be explicitly calculated and included if one wants to attain an accuracy at which double hard scattering becomes relevant, and other situations where such contributions may be neglected.

  14. Single- and double-photoionization cross-sections of nitrogen dioxide (NO2) and ionic fragmentation of NO2+ and NO22+

    International Nuclear Information System (INIS)

    Masuoka, Toshio; Kobayashi, Ataru

    2004-01-01

    Single- and double-photoionization processes of nitrogen dioxide (NO 2 ) have been studied in the photon energy region of 37-125 eV by use of time-of-flight mass spectrometry and the photoion-photoion coincidence method together with synchrotron radiation. The single- and double-photoionization cross-sections of NO 2 are determined. Ion branching ratios and the partial cross-sections for the individual ions, respectively, produced from the parent NO 2 + and NO 2 2+ ions are also determined separately at excitation energies where the molecular and dissociative single- and double-photoionization processes occur simultaneously. It was found that dissociation of the parent ions is dominant both in single and double photoionization. The thresholds for the O + + NO + and N + + O + dissociation channels of NO 2 2+ are at 35.0 ± 0.3 and 43.6 ± 0.3 eV, respectively. Kinetic energy releases in these two dissociation channels of NO 2 2+ have also been elucidated

  15. Experimental study for transient response of a double-tube thermosyphon (DTTH)

    International Nuclear Information System (INIS)

    Salem, M.A.M.

    2010-01-01

    Energy conservation is becoming increasingly important as the cost of fuel continuously rises. The heat pipe and the closed two-phase thermosyphon are particularly effective tools in the heat transfer process.A theoretical and experimental investigation was conducted to study the double-tube two-phase closed-thermosyphon (DTTH) behavior in transient regimes. Experiments were performed to investigate the effects of changing the heating and cooling rate as well as the evaporator length on the double tube thermosyphon in actual integrated operation (start-up, steady-state and shut-down). he necessity for a dynamic model of DTTH for some applications of discontinuous operation imposed the need to the current applied investigation. Therefore, the main objective of the current study is to develop a theoretical model that can predict the dynamic behavior of the double-tube evaporator by tracing various transient parameters during operation from start up to steady state until shut down condition. A model describing both thermal and phase flows of the closed two-phase double tube thermosyphon (DTTH) has been simulated. The theoretical model provides a general description of the behavior of our practical setup based on experimental observations which show a simple exponential behavior. It is based on a two thermal body description (evaporator wall and working fluid) there is good agreement between experiments data and numerical prediction.A computer simulation program based on the method was developed to estimate temperature and the other performance of double tube thermosyphon as well as the time needed to reach steady state condition. The governing equations of the simple 1-D model were solved by Engineering Equation Solver program (EES) using finite difference Euler method. A computer program is designed to solve these differential equations by an explicit finite difference method. The results from this model were found to be in general agreement with the experimental

  16. How thioredoxin dissociates its mixed disulfide.

    Directory of Open Access Journals (Sweden)

    Goedele Roos

    2009-08-01

    Full Text Available The dissociation mechanism of the thioredoxin (Trx mixed disulfide complexes is unknown and has been debated for more than twenty years. Specifically, opposing arguments for the activation of the nucleophilic cysteine as a thiolate during the dissociation of the complex have been put forward. As a key model, the complex between Trx and its endogenous substrate, arsenate reductase (ArsC, was used. In this structure, a Cys29(Trx-Cys89(ArsC intermediate disulfide is formed by the nucleophilic attack of Cys29(Trx on the exposed Cys82(ArsC-Cys89(ArsC in oxidized ArsC. With theoretical reactivity analysis, molecular dynamics simulations, and biochemical complex formation experiments with Cys-mutants, Trx mixed disulfide dissociation was studied. We observed that the conformational changes around the intermediate disulfide bring Cys32(Trx in contact with Cys29(Trx. Cys32(Trx is activated for its nucleophilic attack by hydrogen bonds, and Cys32(Trx is found to be more reactive than Cys82(ArsC. Additionally, Cys32(Trx directs its nucleophilic attack on the more susceptible Cys29(Trx and not on Cys89(ArsC. This multidisciplinary approach provides fresh insights into a universal thiol/disulfide exchange reaction mechanism that results in reduced substrate and oxidized Trx.

  17. Motor Extinction in Distinct Reference Frames: A Double Dissociation

    Directory of Open Access Journals (Sweden)

    Jennifer Heidler-Gary

    2013-01-01

    Full Text Available Objective: Test the hypothesis that right hemisphere stroke can cause extinction of left hand movements or movements of either hand held in left space, when both are used simultaneously, possibly depending on lesion site.

  18. Double Dissociation of Functions in Developmental Dyslexia and Dyscalculia

    Science.gov (United States)

    Rubinsten, Orly; Henik, Avishai

    2006-01-01

    This work examines the association between symbols and their representation in adult developmental dyscalculia and dyslexia. Experiment 1 used comparative judgment of numerals, and it was found that in physical comparisons (e.g., 3-5 vs. 3-5) the dyscalculia group showed a significantly smaller congruity effect than did the dyslexia and the…

  19. Study of flow instabilities in double-channel natural circulation boiling systems

    International Nuclear Information System (INIS)

    Durga Prasad, Gonella V.; Pandey, Manmohan; Pradhan, Santosh K.; Gupta, Satish K.

    2008-01-01

    Natural circulation boiling systems consisting of parallel channels can undergo different types of oscillations (in-phase or out-of-phase) depending on the geometric parameters and operating conditions. Disturbances in one channel affect the flow in other channels, which triggers thermal-hydraulic oscillations. In the present work, the modes of oscillation under different operating conditions and channel-to-channel interaction during power fluctuations and on-power refueling in a double-channel natural circulation boiling system are investigated. The system is modeled using a lumped parameter mathematical model and RELAP5/MOD3.4. Parametric studies are carried out for an equal-power double-channel system, at different operating conditions, with both the models, and the results are compared. Instabilities, non-linear oscillations, and effects of recirculation loop dynamics and geometric parameters on the mode of oscillations, are studied using the lumped model. The two channels oscillate out-of-phase in Type-I region, but in Type-II region, both the modes of oscillation are observed under different conditions. Channel-to-channel interaction and on-power refueling studies are carried out using the RELAP model. At high powers, disturbances in one channel significantly affect the stability of the other channel. During on-power refueling, a near-stagnation condition or low-velocity reverse flow can occur, the possibility of reverse flow being higher at lower pressures

  20. Diagnostic study of multiple double layer formation in expanding RF plasma

    Science.gov (United States)

    Chakraborty, Shamik; Paul, Manash Kumar; Roy, Jitendra Nath; Nath, Aparna

    2018-03-01

    Intensely luminous double layers develop and then expand in size in a visibly glowing RF discharge produced using a plasma source consisting of a semi-transparent cylindrical mesh with a central electrode, in a linear plasma chamber. Although RF discharge is known to be independent of device geometry in the absence of magnetic field, the initiation of RF discharge using such a plasma source results in electron drift and further expansion of the plasma in the vessel. The dynamics of complex plasma structures are studied through electric probe diagnostics in the expanding RF plasma. The measurements made to study the parametric dependence of evolution of double layer structures are analyzed and presented here. The plasma parameter measurements suggest that the complex potential structures initially form with low potential difference between the layers and then gradually expand producing burst oscillations. The present study provides interesting information about the stability of plasma sheath and charge particle dynamics in it that are important to understand the underlying basic sheath physics along with applications in plasma acceleration and propulsion.

  1. [Do double gloves protect against contamination during cannulation of blood vessels? A prospective randomized study].

    Science.gov (United States)

    Szarpak, Łukasz; Kurowski, Andrzej

    2014-01-01

    Undamaged medical gloves protect medical personnel from contact with physiological fluids of the patient. Thus they protect the assistance provider from hand skin contamination with potentially infectious biological materials. The aim of the study was to evaluate the occurrence of pierce, perforations or damage of medical gloves during cannulation of blood vessels. In the prospective randomized study 303 pairs of gloves, used during cannulation of blood vessels under simulated resuscitation, were analyzed. Gloves were tested by the water leak test. The water test revealed 44 cases of damage to the gloves used during cannulation of blood vessels. Significant differences were noted in the frequency of damage to both the outer and single pairs of gloves and the inner pair of gloves. The study showed that the use of double gloves provides a higher level of security for a paramedic than the use of a single pair of gloves, however, double gloves reduce the manual dexterity of a paramedic. A large number of damages to gloves are not noticed by medical personnel during surgery.

  2. Raman and FTIR spectroscopic studies on two hydroxylated tung oils (HTO) bearing conjugated double bonds

    Science.gov (United States)

    Zhuang, Yuwei; Ren, Zhiyong; Jiang, Lei; Zhang, Jiaxiang; Wang, Huafen; Zhang, Guobao

    2018-06-01

    Tung oil (TO) was used as a model compound to study two hydroxylated tung oils (HTO), prepared from TO by either aminolysis (HTO-am) or alcoholysis (HTO-al). Main bands in Raman and FTIR spectra were initially assigned based on the detailed analysis of the compound spectra before and after exposure to elevated temperature (200 °C). The effect of heat treatment in air on spectral bands, and especially on the changes associated with double bonds, were then investigated. In the present work, changes in spectral bands due to heat treatment were compared with those revealed in the previous work of others. The results show that the conjugated triene structure of TO has been retained during alcoholysis and aminolysis, to yield the HTOs studied; yet the change of the triene structure caused by heating is different among the three samples; the H-bonding strength between OH and Cdbnd O in HTO-am is higher than that in HTO-al; the changes in HTO vOH and vCdbnd O bands in FTIR caused by the present heat treatment were significant; for TO, there is a big difference between changes in spectra as caused by thermal exposure, compared to those caused by ageing under UV light or exposure to a catalyst. The present work has laid additional groundwork for further study of the reactions of such triply conjugated double bond structures under different ageing conditions.

  3. Dissociating Effects of Scrambling and Topicalization within the Left Frontal and Temporal Language Areas: An fMRI Study in Kaqchikel Maya.

    Science.gov (United States)

    Ohta, Shinri; Koizumi, Masatoshi; Sakai, Kuniyoshi L

    2017-01-01

    Some natural languages grammatically allow different types of changing word orders, such as object scrambling and topicalization. Scrambling and topicalization are more related to syntax and semantics/phonology, respectively. Here we hypothesized that scrambling should activate the left frontal regions, while topicalization would affect the bilateral temporal regions. To examine such distinct effects in our functional magnetic resonance imaging study, we targeted the Kaqchikel Maya language, a Mayan language spoken in Guatemala. In Kaqchikel, the syntactically canonical word order is verb-object-subject (VOS), but at least three non-canonical word orders (i.e., SVO, VSO, and OVS) are also grammatically allowed. We used a sentence-picture matching task, in which the participants listened to a short Kaqchikel sentence and judged whether a picture matched the meaning of the sentence. The advantage of applying this experimental paradigm to an understudied language such as Kaqchikel is that it will allow us to validate the universality of linguistic computation in the brain. We found that the conditions with scrambled sentences [+scrambling] elicited significant activation in the left inferior frontal gyrus and lateral premotor cortex, both of which have been proposed as grammar centers, indicating the effects of syntactic loads. In contrast, the conditions without topicalization [-topicalization] resulted in significant activation in bilateral Heschl's gyrus and superior temporal gyrus, demonstrating that the syntactic and phonological processes were clearly dissociated within the language areas. Moreover, the pre-supplementary motor area and left superior/middle temporal gyri were activated under relatively demanding conditions, suggesting their supportive roles in syntactic or semantic processing. To exclude any semantic/phonological effects of the object-subject word orders, we performed direct comparisons while making the factor of topicalization constant, and

  4. Double-Balloon Catheter for Isolated Liver Perfusion: An Experimental Study

    International Nuclear Information System (INIS)

    Cwikiel, Wojciech; Bergqvist, Lennart; Harnek, Jan

    2001-01-01

    Purpose: Further development of a previously described interventional method for isolated liver perfusion (ILP) with a new double-lumen balloon catheter, and evaluation of the side-effects of such isolation.Methods: In six pigs a double-balloon occlusion catheter was placed via the transjugular approach with its tip in the portal vein. One of the balloons was positioned in the inferior vena cava (IVC), cranial to the origin of the hepatic veins and the other balloon in the portal vein. By the transfemoral approach, a single-balloon occlusion catheter was placed in the IVC caudal to the origin of the hepatic veins. A third catheter was placed by the transfemoral route with the occlusion balloon in the proper hepatic artery. After inflation of all balloons 99 Tc m -labelled human serum albumin was recirculated through the liver. The isolation was evaluated by repeated measurement of radioactivity levels in peripheral blood. Laboratory tests of liver and pancreas function, and hemoglobin, were taken before, at the end of, and 3 days after the procedure. Blood gases were tested at the beginning and end of the procedure.Results: One pig died during the procedure due to technical failure and was excluded from the study. In the other pigs leakage from the isolated liver to the systemic circulation increased slowly, up to 9.7% (mean) during 30 min of recirculation of the perfusate through the liver. Laboratory tests were normal in all pigs except insignificant acidosis directly after the procedure and the slight elevation of s-ALAT after 3 days.Conclusions: Only minor leakage from the liver to the systemic circulation was noted during ILP performed with a new, double-balloon catheter. There were no serious side effects

  5. Psychiatric comorbidity in patients with conversion disorder and prevalence of dissociative symptoms.

    Science.gov (United States)

    Yayla, Sinan; Bakım, Bahadır; Tankaya, Onur; Ozer, Omer Akil; Karamustafalioglu, Oguz; Ertekin, Hulya; Tekin, Atilla

    2015-01-01

    The 1st objective of the current study was to investigate the frequency and types of dissociative symptoms in patients with conversion disorder (CD). The 2nd objective of the current study was to determine psychiatric comorbidity in patients with and without dissociative symptoms. A total of 54 consecutive consenting patients primarily diagnosed with CD according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, criteria who were admitted to the psychiatric emergency outpatient clinic of Sisli Etfal Research and Teaching Hospital (Istanbul, Turkey) were included in the study. The Structured Clinical Interview for DSM-IV Axis I Disorders, Structured Interview for DSM-IV Dissociative Disorders, and Dissociative Experiences Scale were administered. Study groups consisted of 20 patients with a dissociative disorder and 34 patients without a diagnosis of any dissociative disorder. A total of 37% of patients with CD had any dissociative diagnosis. The prevalence of dissociative disorders was as follows: 18.5% dissociative disorder not otherwise specified, 14.8% dissociative amnesia, and 3.7% depersonalization disorder. Significant differences were found between the study groups with respect to comorbidity of bipolar disorder, past hypomania, and current and past posttraumatic stress disorder (ps = .001, .028, .015, and .028, respectively). Overall comorbidity of bipolar disorder was 27.8%. Psychiatric comorbidity was higher and age at onset was earlier among dissociative patients compared to patients without dissociative symptoms. The increased psychiatric comorbidity and early onset of conversion disorder found in patients with dissociative symptoms suggest that these patients may have had a more severe form of conversion disorder.

  6. Double and triple isotope gamma camera studies with energy selection after data collection

    International Nuclear Information System (INIS)

    Soussaline, F.; Raynaud, C.; Kacperek, A.; Kellershohn, C.; Sauce, M.; Zadje, C.

    1974-01-01

    A system comprising a Toshiba camera and a Informatek data processing system has been used to perform multiple isotope studies. A large window (30-550KeV) is used and the data can be manipulated after data collection, to form sets of dynamic frames for various energies. Linear combinations of matrices have been used to correct for scattering. Double isotope studies using 197Hg/198Au have been used to determine Hg renal uptake in man, and are compared to a previous technique requiring two separate data acquisitions. Animal (pig) renal experiments have been performed using 169 Yb/sup(99m)Tc/ 197 Hg. This pilot study gave good results and indicates the utility of the system for multiple isotope function studies in man [fr

  7. Studies of the wavelength dependence of non-sequential double ionization of xenon in strong fields

    International Nuclear Information System (INIS)

    Kaminski, P.; Wiehle, R.; Kamke, W.; Helm, H.; Witzele, B.

    2005-01-01

    Full text: The non-sequential double ionization of noble gases in strong fields is still a process which is not completely understood. The most challenging question is: what is the dominant physical process behind the knee structure in the yield of doubly charged ions which are produced in the focus of an ultrashort laser pulse in dependence of the intensity? Numerous studies can be explained with the so-called rescattering model, where an electron is freed by the strong laser field and then driven back to its parent ion due to the oscillation of the field. Through this backscattering process it is possible to kick out a second electron. However in the low intensity or multiphoton (MPI) region this model predicts that the first electron can not gain enough energy in the oscillating electric field to further ionize or excite the ion. We present experimental results for xenon in the MPI region which show a significant contribution of doubly charged ions. A Ti:sapphire laser system (800 nm, 100 fs) is used to ionize the atoms. The coincident detection of the momentum distribution of the photoelectrons with an imaging spectrometer and the time of flight spectrum of the ions allows a detailed view into the ionization process. For the first time we also show a systematic study of the wavelength dependence (780-830 nm and 1180-1550 nm) on the non-sequential double ionization. The ratio Xe 2+ /Xe + shows a surprising oscillatory behavior with varying wavelength. Ref. 1 (author)

  8. Double Chooz sensitivity and backgrounds studies to search for θ13 leptonic mixing angle

    International Nuclear Information System (INIS)

    Mention, G.

    2005-06-01

    The Double Chooz experiment will study the oscillations of electron antineutrinos produced by the Chooz nuclear power station to measure θ 13 mixing angle. The current knowledge on this parameter, provided ny the Chooz experiment, can be improved by reducing statistical and systematic errors. A large data sample will be collected to improve the former one. Two identical detectors will be built to cancel most of experimental systematic uncertainties involved in production and detection processes. Special care will be dedicated to backgrounds generated by natural radioactivity and cosmic ray interactions. In the hereby thesis, we describe our simulation studies to compute θ 13 sensitivity and assess the discovery potential of the experiment. We concentrated particularly on quantifying the detector related systematic errors that would limit the θ 13 sensitivity. Background related systematic errors such as the accidental events produced by the radioactivity of the photomultiplier tubes, correlated events from neutrons as well as a hypothetical background (mimicking the oscillation pattern) were taken into account. After 3 years, Double Chooz will be able to disentangle an oscillation signal for sin 2 (2*θ 13 ) > 0.05 (at 3*σ) or, if no oscillations were observed, to put a limit of sin 2 (2θ 13 ) < 0.03 at 90% C.L. (author)

  9. DISSOCIATIVE DISORDERS IN DSM-5

    NARCIS (Netherlands)

    Spiegel, David; Loewenstein, Richard J.; Lewis-Fernandez, Roberto; Sar, Vedat; Simeon, Daphne; Vermetten, Eric; Cardena, Etzel; Dell, Paul F.

    Background: We present recommendations for revision of the diagnostic criteria for the Dissociative Disorders (DDs) for DSM-5. The periodic revision of the DSM provides an opportunity to revisit the assumptions underlying specific diagnoses and the empirical support, or lack of it, for the defining

  10. Hydrogen dissociation on metal surfaces

    NARCIS (Netherlands)

    Wijzenbroek, M.

    2016-01-01

    Dissociative chemisorption is an important reaction step in many catalytic reactions. An example of such a reaction is the Haber-Bosch process, which is used commercially to produce ammonia, an important starting material in the production of fertilisers. In theoretical descriptions of such chemical

  11. Can the dissociative PTSD subtype be identified across two distinct trauma samples meeting caseness for PTSD?

    Science.gov (United States)

    Hansen, Maj; Műllerová, Jana; Elklit, Ask; Armour, Cherie

    2016-08-01

    For over a century, the occurrence of dissociative symptoms in connection to traumatic exposure has been acknowledged in the scientific literature. Recently, the importance of dissociation has also been recognized in the long-term traumatic response within the DSM-5 nomenclature. Several studies have confirmed the existence of the dissociative posttraumatic stress disorder (PTSD) subtype. However, there is a lack of studies investigating latent profiles of PTSD solely in victims with PTSD. This study investigates the possible presence of PTSD subtypes using latent class analysis (LCA) across two distinct trauma samples meeting caseness for DSM-5 PTSD based on self-reports (N = 787). Moreover, we assessed if a number of risk factors resulted in an increased probability of membership in a dissociative compared with a non-dissociative PTSD class. The results of LCA revealed a two-class solution with two highly symptomatic classes: a dissociative class and a non-dissociative class across both samples. Increased emotion-focused coping increased the probability of individuals being grouped into the dissociative class across both samples. Social support reduced the probability of individuals being grouped into the dissociative class but only in the victims of motor vehicle accidents (MVAs) suffering from whiplash. The results are discussed in light of their clinical implications and suggest that the dissociative subtype can be identified in victims of incest and victims of MVA suffering from whiplash meeting caseness for DSM-5 PTSD.

  12. Dissociative tendencies and individual differences in high hypnotic suggestibility.

    Science.gov (United States)

    Terhune, Devin Blair; Cardeña, Etzel; Lindgren, Magnus

    2011-03-01

    Inconsistencies in the relationship between dissociation and hypnosis may result from heterogeneity among highly suggestible individuals, in particular the existence of distinct highly suggestible subtypes that are of relevance to models of psychopathology and the consequences of trauma. This study contrasted highly suggestible subtypes high or low in dissociation on measures of hypnotic responding, cognitive functioning, and psychopathology. Twenty-one low suggestible (LS), 19 low dissociative highly suggestible (LDHS), and 11 high dissociative highly suggestible (HDHS) participants were administered hypnotic suggestibility scales and completed measures of free recall, working memory capacity, imagery, fantasy-proneness, psychopathology, and exposure to stressful life events. HDHS participants were more responsive to positive and negative hallucination suggestions and experienced greater involuntariness during hypnotic responding. They also exhibited impaired working memory capacity, elevated pathological fantasy and dissociative symptomatology, and a greater incidence of exposure to stressful life events. In contrast, LDHS participants displayed superior object visual imagery. These results provide further evidence for two highly suggestible subtypes: a dissociative subtype characterised by deficits in executive functioning and a predisposition to psychopathology, and a subtype that exhibits superior imagery and no observable deficits in functioning.

  13. Ionisation and dissociation of water induced by swift multicharged ions

    International Nuclear Information System (INIS)

    Legendre, S.

    2006-02-01

    Ionization and dissociation of water molecules and water clusters induced by 11.7 MeV/A Ni 25+ ions were carried out by imaging techniques. Branching ratios, ionisation cross sections and Kinetic Energy Released distributions have been measured together with fragmentation dynamics studies. Multiple ionization represents approximately 30% of the ionizing events. Double ionization produces in significant way atomic oxygen, considered as a possible precursor of the large production of HO 2 radical in liquid water radiolysis by ions of high Linear Energy Transfer. We evidence a strong selectivity of bond breakage in the case of ion-induced HOD fragmentation. Once the molecule doubly ionized, the breakage of the O-H bond is found 6.5 times more probable than that of the O-D bond. A semi-classical calculation simulating the fragmentation dynamics on the potential energy surface of the ground-state of di-cation H 2 O 2+ makes possible to as well reproduce the preferential nature of the breakage of the O-H bond as the position and the shift of the kinetic energy distributions. First results concerning interaction with water clusters are also reported. Measurements in coincidence are carried out giving access to correlation, with the distributions in energy and angle of the emitted fragments. Mass spectrum points fast intra-cluster proton transfer, leading to the emission of protonated clusters. (author)

  14. Phlebitis induced by parenteral treatment with flucloxacillin and cloxacillin: a double-blind study.

    Science.gov (United States)

    Svedhem, A; Alestig, K; Jertborn, M

    1980-01-01

    Two studies were performed on a total of 54 patients with staphylococcal infections. Study I compares with phlebitogenic properties of flucloxacillin after intravenous infusions when either saline or sterile water was used as a solvent. No difference was observed between the two solvents, and the frequency of phlebitis for the total material without respect to solvents was 5% after 1 day of treatment and 13% after 2 days. Study II was a double-blind comparison of phlebitis caused by intravenous infusions of either flucloxacillin or cloxacillin. The frequencies of phlebitis were found to be 18 and 13%, respectively. After 2 days of treatment the frequency of phlebitis increased dramatically for both drugs. All infusions were given through a plastic cannula of 5-cm length and 1.2-mm diameter. PMID:7447412

  15. Studies on electrodeposited silver sulphide thin films by double exposure holographic interferometry

    International Nuclear Information System (INIS)

    Prabhune, V.B.; Shinde, N.S.; Fulari, V.J.

    2008-01-01

    Silver sulphide (Ag 2 S) thin films have been deposited on to stainless steel and fluorine doped tin oxide (FTO) glass substrates by the electrodeposition process, in potentiostatic mode using silver nitrate (AgNO 3 ), sodium thiosulphate (Na 2 S 2 O 3 ) as a precursor sources and Ethylene Diamine Tetra Acetic Acid (EDTA) was used as a complexing agent. The deposition potential of the compound was investigated by cyclic voltammetry. The structural and optical properties of the deposited films have been studied using X-ray diffraction (XRD) and optical absorption techniques, respectively. XRD studies reveal that the films are polycrystalline with monoclinic crystal structure. Optical absorption study shows the presence of direct transition with bandgap energy 1.1 eV. The determination of thickness and stress of the Ag 2 S thin films was carried out by Double Exposure Holographic Interferometry (DEHI) technique.

  16. Global functioning and disability in dissociative disorders.

    Science.gov (United States)

    Mueller-Pfeiffer, Christoph; Rufibach, Kaspar; Perron, Noelle; Wyss, Daniela; Kuenzler, Cornelia; Prezewowsky, Cornelia; Pitman, Roger K; Rufer, Michael

    2012-12-30

    Dissociative disorders are frequent comorbid conditions of other mental disorders. Yet, there is controversy about their clinical relevance, and little systematic research has been done on how they influence global functioning. Outpatients and day care patients (N=160) of several psychiatric units in Switzerland were assessed with the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV Axis I Disorders, Structured Clinical Interview for DSM-IV Dissociative Disorders, Global Assessment of Functioning Scale, and World Health Organization Disability Assessment Schedule-II. The association between subjects with a dissociative disorder (N=30) and functional impairment after accounting for non-dissociative axis I disorders was evaluated by linear regression models. We found a proportion of 18.8% dissociative disorders (dissociative amnesia=0%, dissociative fugue=0.6%, depersonalization disorder=4.4%, dissociative identity disorder=7.5%, dissociative disorder-not-otherwise-specified=6.3%) across treatment settings. Adjusted for other axis I disorders, subjects with a comorbid dissociative identity disorder or dissociative disorder-not-otherwise-specified had a median global assessment of functioning score that was 0.86 and 0.88 times, respectively, the score of subjects without a comorbid dissociative disorder. These findings support the hypothesis that complex dissociative disorders, i.e., dissociative identity disorder and dissociative disorder-not-otherwise-specified, contribute to functional impairment above and beyond the impact of co-existing non-dissociative axis I disorders, and that they qualify as "serious mental illness". Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  17. Signal and background studies for the search of neutrinoless double beta decay in GERDA

    Energy Technology Data Exchange (ETDEWEB)

    Agostini, Matteo

    2013-04-24

    The GERDA experiment searches for the neutrinoless double beta decay in Ge-76, by operating bare HPGe detectors in ultra-pure liquid Ar. This dissertation presents a first decomposition of the background measured in the current data-taking phase. The background at the energy of interest was found to be dominated by {sup 214}Bi, {sup 208}Tl and {sup 42}K gamma-rays, with secondary contributions from {sup 42}K and {sup 214}Bi beta-rays, and {sup 210}Po alpha-rays. For the forthcoming upgrade of the apparatus, a new HPGe detector design (BEGe) has been studied, with focus on its capability of suppressing the identified backgrounds through pulse shape analysis. This included the development of a comprehensive modeling of the detectors and the experimental characterization of their response to surface interactions. The achieved results show that GERDA can improve the present limit on the neutrinoless double beta decay half-life by an order of magnitude.

  18. Interlayer Structures and Dynamics of Arsenate and Arsenite Intercalated Layered Double Hydroxides: A First Principles Study

    Directory of Open Access Journals (Sweden)

    Yingchun Zhang

    2017-03-01

    Full Text Available In this study, by using first principles simulation techniques, we explored the basal spacings, interlayer structures, and dynamics of arsenite and arsenate intercalated Layered double hydroxides (LDHs. Our results confirm that the basal spacings of NO3−-LDHs increase with layer charge densities. It is found that Arsenic (As species can enter the gallery spaces of LDHs with a Mg/Al ratio of 2:1 but they cannot enter those with lower charge densities. Interlayer species show layering distributions. All anions form a single layer distribution while water molecules form a single layer distribution at low layer charge density and a double layer distribution at high layer charge densities. H2AsO4− has two orientations in the interlayer regions (i.e., one with its three folds axis normal to the layer sheets and another with its two folds axis normal to the layer sheets, and only the latter is observed for HAsO42−. H2AsO3− orientates in a tilt-lying way. The mobility of water and NO3− increases with the layer charge densities while As species have very low mobility. Our simulations provide microscopic information of As intercalated LDHs, which can be used for further understanding of the structures of oxy-anion intercalated LDHs.

  19. Study of magnetic properties for co double-nanorings: Monte Carlo simulation

    International Nuclear Information System (INIS)

    Ye, Qingying; Chen, Shuiyuan; Liu, Jingyao; Huang, Chao; Huang, Shengkai; Huang, Zhigao

    2016-01-01

    In this paper, cobalt double-nanorings (Co D-N-rings) structure model was constructed. Based on Monte-Carlo simulation (MC) method combining with Fast Fourier Transformation and Micromagnetism (FFTM) method, the magnetic properties of Co D-N-rings with different geometric dimensions have been studied. The simulated results indicate that, the magnetization steps in hysteresis loops is the result of the special spin configurations (SCs), i.e., onion-type state and vortex-type state, which are very different from that in many other nanostructures, such as nanometer thin-films, nanotubes, etc. Besides, Co D-N-rings with different geometric dimensions present interesting magnetization behavior, which is determined by the change of both SCs and exchange interaction in Co D-N-rings. - Highlights: • A double-nanorings structure (named as D-N-rings) was proposed to construct cobalt nanometer thin film. • Monte Carlo method combining with FFTM method was used to simulate magnetic properties of the Co D-N-rings. • Magnetization dynamic processes of the Co D-N-rings were obtained and interpreted through the evolutionary process of spin configurations. • Geometric dimensions deeply influence the magnetization behavior of the Co D-N-rings, which is determined by the change of both SCs and exchange interaction.

  20. Hydroxyurea: a radiation potentiator in carcinoma of the uterine cervix. A randomized double-blind study

    International Nuclear Information System (INIS)

    Piver, M.S.; Barlow, J.J.; Vongtama, V.; Blumenson, L.

    1983-01-01

    From June, 1972, to December, 1976, 40 patients with FIGO (International Federation of Gynaecology and Obstetrics) Stage IIB carcinoma of the uterine cervix were entered into a prospective, double-blind, randomized study to evaluate the possible radiation-potentiating properties (i.e., improved survival) of the S-phase cell cycle-specific inhibitor of DNA synthesis, hydroxyurea. All patients were documented to be without aortic lymph node metastasis by pretherapy staging para-aortic lymphadenectomy. All 40 patients were followed up for longer than 5 years (5.2 to 9.2 years) or until death. The double-blind code was not broken until all patients had been followed up for a minimum of 2 to 5 years. Leukopenia (white blood cell count less than 2,500 mm3) was significantly increased in the patients given hydroxyurea as compared to those given placebo (P less than 0.0001). There was no statistically significant difference relative to anemia, thrombocytopenia, radiation-induced skin reaction, and radiation-induced intestinal reaction between the patients given placebo or those given hydroxyurea. Life-table survival for the patients given hydroxyurea was 94% as compared to 53% for the patients given placebo (P . 0.006). Only one (5%) patient given hydroxyurea died of cervical cancer. Of the other patients who died in the group given hydroxyurea, all were confirmed by postmortem examination to have been without recurrent cervical cancer. In contrast, 45% (nine) of the patients given placebo died of cervical cancer