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Sample records for spontaneous dissociation dissociation

  1. Dissociative Disorders

    Science.gov (United States)

    ... actions and identity. People with dissociative disorders escape reality in ways that are involuntary and unhealthy and ... conditions. Complications People with dissociative disorders are at increased risk of complications and associated disorders, such as: ...

  2. Dissociative Disorders

    Science.gov (United States)

    ... that's frightening or highly unpredictable. The stress of war or natural disasters also can bring on dissociative ... adults who experience other traumatic events, such as war, natural disasters, kidnapping, torture, or extended, traumatic, early- ...

  3. Differences between sexes in dissociation and spontaneity of smile in facial paralysis reanimation with the masseteric nerve.

    Science.gov (United States)

    Hontanilla, Bernardo; Marre, Diego

    2014-08-01

    A patient's sex is likely to play an important role in facial paralysis reanimation, with women being superior in terms of development of brain plasticity after reanimation. The purpose of this study was to compare the rate of movement dissociation and spontaneity of men versus women reanimated with gracilis transfer neurotized to the masseteric nerve. We conducted a retrospective chart review of 27 patients who underwent facial paralysis reanimation with microvascular gracilis transplants neurotized to the ipsilateral masseteric nerve. Patients were classified by sex, comparing age at surgery, denervation time, and follow-up, as well as the rates of movement dissociation and smile spontaneity. After reanimation with gracilis to masseteric nerve, movement dissociation and spontaneity were higher in women during the first year after onset of facial movement (p=.02 and p=.01, respectively). After reanimation with masseteric nerve, women seem to be able to smile spontaneously and independently from teeth clenching earlier than men. Copyright © 2013 Wiley Periodicals, Inc.

  4. Five cases of early dissociation between the bipolar hip endoprosthesis cup components; either spontaneously or during reduction maneuvers

    Directory of Open Access Journals (Sweden)

    Vedat Uruç

    2017-03-01

    Full Text Available Bipolar hemiarthroplasty is frequently used in the treatment of intracapsular hip fractures. Dissociation of the bipolar components can happen during the hip dislocation, the reduction maneuvers, or spontaneously without any dislocation. Here we report early dissociation between bipolar components in two cases during the attempt of closed reduction maneuvers and three cases with spontaneous dissociation without any trauma. To prevent or minimize this complication; the reduction of dislocated hips must be achieved very gently under general anesthesia with fluoroscopic control. During the initial operation the surgeons must be sure that the bipolar components are locked to each other and after final reduction, especially in osteoarthritic acetabulums, that the cup position is not in varus position.

  5. 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.

  6. Impairments of spontaneous and deliberative mentalizing co-occur, yet dissociate, in schizophrenia.

    Science.gov (United States)

    Langdon, Robyn; Flynn, Michaela; Connaughton, Emily; Brüne, Martin

    2017-11-01

    Evidence of impairment in explicit mentalizing in people with schizophrenia has inspired interventions to improve awareness of others' mental states in these individuals. Less is known of implicit mentalizing in schizophrenia, with current findings mixed. We sought to resolve previous inconsistencies using Heider & Simmel's (H&S) classic animation to elicit spontaneous mentalizing and examined relations between spontaneous and deliberative mentalizing. Forty-five schizophrenia outpatients and 27 general-community controls completed two explicit theory-of-mind (TOM) tasks and then described the H&S animation (to elicit spontaneous social attributions about emotionally driven, as well as goal-driven, behaviours), before and after an instruction to think of the shapes as people. Accuracy of basic and social facts and frequencies of personification and different mental-state terms were recorded. Explicit TOM performance was impaired in patients. Patients also generated fewer social (but not basic) facts than controls to describe the H&S animation, and used less mental-state language, before, and even more so, after the 'people' instruction, despite that both groups had used more personification terms after the 'people' instruction. Measures of explicit and spontaneous mentalizing contributed independently to discriminating between groups. Patients respond less to the bottom-up signals of agency that ought normally to elicit spontaneous social attributions, even when cued to think of the stimuli as people, and the stimuli depict emotionally driven, as well as goal-driven, behaviour. That impairments of spontaneous and deliberative mentalizing dissociate in schizophrenia suggests that training deliberative mentalizing may not be enough; interventions to improve spontaneous mentalizing are also needed. Findings People with schizophrenia were less likely than controls to spontaneously attribute causal mental states when viewing dynamic signals of emotionally driven and

  7. Deuteron diffractive dissociation

    International Nuclear Information System (INIS)

    Antunes, A.C.B.; Caruso, F.

    1984-01-01

    Deuteron diffractive dissociation is studied in the framework of the Three Components Deck Model. The applicability of this model to light nuclei diffractive dissociation is assumed. The existence of a slope-mass-cos theta correlation is pointed out. The relevant distributions are obtained. (Author) [pt

  8. Dissociated methanol test results

    Energy Technology Data Exchange (ETDEWEB)

    Finegold, J.G.; McKinnon, J.T.

    1982-04-01

    The design and testing of an automotive fuel system that provides hydrogen-rich gases to an internal combustion engine by catalytically cracking, or dissociating, methanol on board the vehicle is described. The vaporization and dissociation of methanol absorb heat from the engine exhaust and increase the lower heating value of the fuel by approximately 22%. In addition, raising the compression ratio and burning with excess air increase the engine thermal efficiency. Engine dynamometer test results with dissociated methanol demonstrated improvement in brake thermal efficiency compared to gasoline from 30% to 100% depending on engine speed and torque. Lower speeds and torques produce the largest improvements. Maps of exhaust temperature and exhaust heat content are presented. The exhaust temperature is almost always high enough for dissociation to occur, but at lower power outputs, there is only enough exhaust energy for partial dissociation of the methanol.

  9. Spontaneous and Deliberate Dissociative States in Military Personnel: Relationships to Objective Performance Under Stress

    Science.gov (United States)

    2014-09-01

    More specifically, the potential utility of deliberate dissociation may depend on whether the context requires cog- nitive engagement with a dynamic...7. 5. Morgan CA III, Rasmusson AM, Wang S, Hoyt G, Hauger RL, Hazlett G: Neuropeptide Y , cortisol, and subjective distress in humans exposed to acute...underwater navigation stress. Biol Psychiatry 2009; 66(4): 334 40. 15. Morgan III CA, Russell B, McNeil J, et al: Baseline burnout symptoms predict

  10. Spontaneous Isomerization of Peptide Cation Radicals Following Electron Transfer Dissociation Revealed by UV-Vis Photodissociation Action Spectroscopy

    Science.gov (United States)

    Imaoka, Naruaki; Houferak, Camille; Murphy, Megan P.; Nguyen, Huong T. H.; Dang, Andy; Tureček, František

    2018-01-01

    Peptide cation radicals of the z-type were produced by electron transfer dissociation (ETD) of peptide dications and studied by UV-Vis photodissociation (UVPD) action spectroscopy. Cation radicals containing the Asp (D), Asn (N), Glu (E), and Gln (Q) residues were found to spontaneously isomerize by hydrogen atom migrations upon ETD. Canonical N-terminal [z4 + H]+● fragment ion-radicals of the R-C●H-CONH- type, initially formed by N-Cα bond cleavage, were found to be minor components of the stable ion fraction. Vibronically broadened UV-Vis absorption spectra were calculated by time-dependent density functional theory for several [●DAAR + H]+ isomers and used to assign structures to the action spectra. The potential energy surface of [●DAAR + H]+ isomers was mapped by ab initio and density functional theory calculations that revealed multiple isomerization pathways by hydrogen atom migrations. The transition-state energies for the isomerizations were found to be lower than the dissociation thresholds, accounting for the isomerization in non-dissociating ions. The facile isomerization in [●XAAR + H]+ ions (X = D, N, E, and Q) was attributed to low-energy intermediates having the radical defect in the side chain that can promote hydrogen migration along backbone Cα positions. A similar side-chain mediated mechanism is suggested for the facile intermolecular hydrogen migration between the c- and [z + H]●-ETD fragments containing Asp, Asn, Glu, and Gln residues. [Figure not available: see fulltext.

  11. Spontaneous Isomerization of Peptide Cation Radicals Following Electron Transfer Dissociation Revealed by UV-Vis Photodissociation Action Spectroscopy.

    Science.gov (United States)

    Imaoka, Naruaki; Houferak, Camille; Murphy, Megan P; Nguyen, Huong T H; Dang, Andy; Tureček, František

    2018-01-16

    Peptide cation radicals of the z-type were produced by electron transfer dissociation (ETD) of peptide dications and studied by UV-Vis photodissociation (UVPD) action spectroscopy. Cation radicals containing the Asp (D), Asn (N), Glu (E), and Gln (Q) residues were found to spontaneously isomerize by hydrogen atom migrations upon ETD. Canonical N-terminal [z 4 + H] +● fragment ion-radicals of the R-C ● H-CONH- type, initially formed by N-C α bond cleavage, were found to be minor components of the stable ion fraction. Vibronically broadened UV-Vis absorption spectra were calculated by time-dependent density functional theory for several [ ● DAAR + H] + isomers and used to assign structures to the action spectra. The potential energy surface of [ ● DAAR + H] + isomers was mapped by ab initio and density functional theory calculations that revealed multiple isomerization pathways by hydrogen atom migrations. The transition-state energies for the isomerizations were found to be lower than the dissociation thresholds, accounting for the isomerization in non-dissociating ions. The facile isomerization in [ ● XAAR + H] + ions (X = D, N, E, and Q) was attributed to low-energy intermediates having the radical defect in the side chain that can promote hydrogen migration along backbone C α positions. A similar side-chain mediated mechanism is suggested for the facile intermolecular hydrogen migration between the c- and [z + H] ● -ETD fragments containing Asp, Asn, Glu, and Gln residues. Graphical Abstract ᅟ.

  12. Genomic Island 2 Is an Unstable Genetic Element Contributing to Brucella Lipopolysaccharide Spontaneous Smooth-to-Rough Dissociation ▿ †

    Science.gov (United States)

    Mancilla, Marcos; López-Goñi, Ignacio; Moriyón, Ignacio; Zárraga, Ana María

    2010-01-01

    Brucella is a Gram-negative bacterium that causes a worldwide-distributed zoonosis. The genus includes smooth (S) and rough (R) species that differ in the presence or absence, respectively, of the O-polysaccharide of lipopolysaccharide. In S brucellae, the O-polysaccharide is a critical diagnostic antigen and a virulence determinant. However, S brucellae spontaneously dissociate into R forms, a problem in antigen and S vaccine production. Spontaneous R mutants of Brucella abortus, Brucella melitensis, and Brucella suis carried the chromosomal scar corresponding to genomic island 2 (GI-2) excision, an event causing the loss of the wboA and wboB O-polysaccharide genes, and the predicted excised circular intermediate was identified in B. abortus, B. melitensis, and B. suis cultures. Moreover, disruption of a putative phage integrase gene in B. abortus GI-2 caused a reduction in O-polysaccharide loss rates under conditions promoting S-R dissociation. However, spontaneous R mutants not carrying the GI-2 scar were also detected. These results demonstrate that the phage integrase-related GI-2 excision is a cause of S-R brucella dissociation and that other undescribed mechanisms must also be involved. In the R Brucella species, previous works have shown that Brucella ovis but not Brucella canis lacks GI-2, and a chromosomal scar identical to those in R mutants was observed. These results suggest that the phage integrase-promoted GI-2 excision played a role in B. ovis speciation and are consistent with other evidence, suggesting that this species and B. canis have emerged as two independent lineages. PMID:20952568

  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. 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.

  15. 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…

  16. 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.

  17. Dissociation of motor maturation.

    Science.gov (United States)

    DiMario, Francis J

    2003-06-01

    We prospectively acquired clinical data regarding the presentation, evaluation, and developmental progress of all patients identified with dissociated motor maturation to define their clinical outcomes. Children (N = 8) referred for evaluation of suspected cerebral palsy because of delayed sitting or walking and identified to have dissociated motor maturation were followed with serial clinical examination. All displayed the characteristic "sitting on air" posture while held in vertical suspension and had otherwise normal developmental assessments. This posture is composed of the hips held in flexion and abduction with the knees extended and feet plantar or dorsiflexed. Three children were initially evaluated at 10 months of age owing to absence of sitting and five other children were evaluated at a mean of 14 months (range 12-19 months) owing to inability to stand. Follow-up evaluations were conducted over a mean of 10.5 months (range 5-34 months). Five children were born prematurely at 34 to 36 weeks gestation. Denver Developmental Screening Test and general and neurologic examinations were normal except to note hypotonia in six children and the "sitting on air" posture in all of the children. Four children have older siblings or parents who "walked late" (after 15 months). On average, the children attained sitting by 8 months (range 7-10 months). One child did not crawl prior to independent walking, two children scooted rather than crawled, and five children crawled at an average of 13.5 months (range 10-16 months). All children cruised by a mean of 18 months (range 16-21.5 months) and attained independent walking by 20.1 months (range 18-25 months). Neuroimaging and serum creatine kinase enzyme testing were normal in two children who were tested. These eight children conform to the syndrome of dissociated motor maturation. The "sitting on air" posture serves as a diagnostic sign and anticipated excellent prognosis, but follow-up is required to ensure a normal

  18. [Dissociative disorders and affective disorders].

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    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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Trauma and dissociation: treatment perspectives.

    Science.gov (United States)

    Kreidler, M C; Zupancic, M K; Bell, C; Longo, M B

    2000-01-01

    How advanced practice nurses can work with trauma survivors to decrease dissociation as a needed coping mechanism. To review the literature on trauma and dissociation as well as current treatment perspectives. Review of the literature and authors' clinical experience. Advanced practice nurses can use knowledge of selected psychopharmacological medications and Erikson's stages of psychosocial development to plan treatment for posttrauma clients.

  4. Dissociation: a developmental psychoneurobiological perspective ...

    African Journals Online (AJOL)

    Dissociation is a common symptom of a spectrum of severe psychopathologies, from reactive attachment disorder of infants to dissociative identity disorders, psychotic experiences, borderline personality disorders and post-traumatic stress disorders of adults. The incidence of abuse in the childhood histories of adults with ...

  5. AV dissociation, an inevitable response.

    Science.gov (United States)

    Wang, Kyuhyun; Benditt, David G

    2011-07-01

    The independent activation of the atria and ventricles, AV dissociation, is a common phenomenon that occurs during a wide variety of electrophysiologic circumstances. The clinical significance of AV dissociation is often misunderstood. This article examines the basis and clinical implications of AV dissociation. AV dissociation is often an obligatory, secondary phenomenon, and should not be construed as the primary disorder; it may be due to either the AV conduction system being completely blocked (3° AV block) or the P wave and the QRS complex being generated from separate sources (usually, the AV junction or ventricle) but occurring close together during the physiologic refractory period of each other. The latter may happen in junctional or ventricular arrhythmias including escape or accelerated rhythm, tachycardia, or premature beats. The crucial clinical point is not the AV dissociation itself, but that an underlying triggering primary disorder is present and should be identified. ©2011, Wiley Periodicals, Inc.

  6. Neurolinguistic features of spontaneous language production dissociate three forms of neurodegenerative disease: Alzheimer's, Huntington's, and Parkinson's.

    Science.gov (United States)

    Illes, J

    1989-11-01

    An analysis of the temporal (prospective) form (silent and filled hesitations, repetitions, incomplete phrases, context-related comments, interjections), syntactic form, and lexical (retrospective) form (verbal deviations, open and closed class phrases) of spontaneous language production of early and middle stage Alzheimer's, Huntington's, and Parkinson's patients was made. Results showed that the language structure was disrupted in each disease, but in different ways. Temporal interruptions of varying types were frequent in the language of Alzheimer's and Huntington's Disease patients; only long-duration silent hesitations were frequent in Parkinson's language samples. Syntactic complexity was reduced in Huntington's Disease. Verbal paraphasias were found in both the language of Alzheimer's patients, as well as moderately advanced Huntington's patients. Closed class phrases were predominant in the language of Alzheimer's patients and Huntington's patients, and open class phrases in the language of Parkinson's patients. Taken together, the results suggest that (1) there is a unique neurolinguistic profile for spontaneous language production for each neurodegenerative disease, (2) pathology of the neostriatum disrupts syntactic organization, (3) adaptive strategies are used to cope with verbal and speech-motor difficulties, and (4) adaptive strategies fail to be effective with increasing disease severity.

  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. 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

  9. Multiphoton dissociative ionization of CS+

    Science.gov (United States)

    Rajput, Jyoti; Jochim, Bethany; Zohrabi, M.; Betsch, K. J.; Ablikim, U.; Berry, Ben; Severt, T.; Summers, A. M.; Armstrong, G. S. J.; Esry, B. D.; Carnes, K. D.; Ben-Itzhak, I.

    2015-05-01

    We have studied the dissociative photoionization of a CS+ molecular ion beam in the strong-field regime using process. Two prominent channels were observed: charge-symmetric dissociation, yielding C+ + S+, and charge-asymmetric dissociation, yielding C + S2+. The differences between these two channels with reference to their relative production probability, energetics, and angular distributions is the focus of this work. This work was supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy. BJ is also supported by DOE-SCGF (DE-AC05-06OR23100).

  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. 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

  12. 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.

  13. Dissociative symptoms in pathological gambling.

    Science.gov (United States)

    Grant, Jon E; Kim, Suck Won

    2003-01-01

    Dissociation is increasingly being recognized as both a normal process and as a psychophysiological aspect of a number of mental disorders. The purpose of this investigation was to shed light on a possible link between dissociation and pathological gambling, a relatively common disorder whose phenomenology remains understudied. Thirty adult outpatients who met DSM-IV criteria for pathological gambling and had no comorbidity were administered the Dissociative Experiences Scale (DES). The pathological gamblers had DES scores that did not significantly differ from those reported by normal controls (t = -0.620; d.f. = 29; p = 0.540). Pathological gamblers do not appear to experience dissociative symptoms (as reflected on the DES) at a rate significantly different from those found in normal controls. Because pathological gamblers seeking medication treatment, as in this study, may differ from others with pathological gambling, further studies are needed. Copyright 2003 S. Karger AG, Basel

  14. 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)

  15. 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.

  16. Thermodynamic properties of dissociated steam

    Science.gov (United States)

    Aminov, R. Z.; Gudym, A. A.

    2017-11-01

    In connection with the development of hydrogen technologies and the generation of dissociated steam as a result of the oxidation of hydrogen in an oxygen environment, it became necessary to determine the calorific parameters of dissociated steam. In the existing tables, the caloric parameters of dissociated steam are presented at a reference temperature of 0 K. By contrast, the authors have developed tables of dissociated steam using a reference temperature of 0°C, within the pressure range 0.01–20.0 MPa and the temperature range 1250–4000 K, along with a system of equations for the industrial calculation of the properties of dissociated steam within the temperature range 1250–2300 K and pressure range 0.01–10.0 MPa, followed by a temperature range of 2200–3600 K. During the dissociation of steam, a mixture of eight components are formed including hydrogen H, oxygen O, radicals OH and HO2, molecules of hydrogen H2, oxygen O2, steam H2O, and hydrogen peroxide H2O2. All existing tables of the properties of dissociated steam are based on a mixture of six components: H2, O2, OH, H, O, and H2O. For evaluate whether this is an oversimplification, the composition of the mixture comprising all eight components was calculated, taking into account additional chemical reactions for the formation of HO2 and H2O2. At a pressure of 0.01 MPa, the maximum mole fraction of HO2 was 2.8·10‑5 at a temperature of 3000 K, and at a pressure of 10 MPa, the maximum mole fraction was 5·10‑5 at a temperature of 4000 K. The mole fraction of H2O2 was much lower. Thus at temperatures up to 3000 K, calculations of the properties of dissociated steam are restricted to six components.

  17. 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.

  18. Dissociative Experiences and Vividness of Auditory Imagery

    Science.gov (United States)

    Pérez-Fabello, María José; Campos, Alfredo

    2017-01-01

    The relationship between dissociation and auditory imagery were assessed, 2 variables that sometime influence on artistic creativity. A total of 170 fine arts undergraduates (94 women and 76 men) received 2 dissociation questionnaires--the Dissociative Ability Scale (DAS), and the Dissociative Experiences Scale (DES)--and 2 auditory imagery…

  19. [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.

  20. 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...

  1. 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

  2. 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

  3. Modelfree determination of dissociation energies

    International Nuclear Information System (INIS)

    Vogel, M.; Herlert, A.; Hansen, K.; Schweikhard, L.

    2002-01-01

    The most fundamental parameter in the characterization of any free stable polyatomic particle (molecule, fullerene, polymer or cluster) is its dissociation energy, which reflects structural and dynamical properties of the system under investigation. A new method to determine the dissociation energy (DE) is presented. It allows a DE direct measurement without any assumptions on how the disintegration process proceeds, does not relay on any model of the system, or other properties. Its basic idea is to compare the excitation energy E A of a sequential decay ( A-->B-->C) with the corresponding energy E B of the single decay (B-->C) that leads to the final product. When the single decay process depends in a measurable way on the amount of excitation energy present, it can be used as an uncalibrated thermometer for the last step of the sequential reaction. Adjusting either of the two excitation energies E A and E B to produce the same reading of the thermometer, the difference in excitation energies, E A - E B , is a direct measure of the energy consumed in the first step of the sequential decay, thus is the dissociation energy of A. As an example, dissociation energies of a series of gold clusters Au n + (n=14-24) were determined. (nevyjel)

  4. 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

  5. Dissociating Prediction Failure: Considerations from Music Perception

    DEFF Research Database (Denmark)

    Ross, Suzi; Hansen, Niels Christian

    2016-01-01

    Dissociating Prediction Failure: Considerations from Music Perception The Journal of Neuroscience, 16 March 2016, 36(11): 3103-3105;......Dissociating Prediction Failure: Considerations from Music Perception The Journal of Neuroscience, 16 March 2016, 36(11): 3103-3105;...

  6. 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.

  7. From dissociation to trauma? Individual differences in dissociation as predictor of 'trauma' perception.

    Science.gov (United States)

    Rassin, Eric; van Rootselaar, Anne-Fleur

    2006-06-01

    In clinical literature, dissociative complaints are generally considered to be the result of traumatic experiences. However, it has been argued that dissociative complaints, in turn, may indulge over-reporting of traumatic experiences. Hence, correlations between dissociation and self-reported trauma may not only reflect the causal path from trauma to dissociation, but possibly also an increased trauma-item endorsement due to dissociation. To test the idea that dissociation fosters a positive response bias on trauma self-reports, participants completed a dissociation scale, and subsequently rated the perceived trauma of ambiguous stimuli. Results indicated that some dissociative complaints indeed predicted increased scores on the trauma ratings, while other manifestations of dissociation were negatively correlated with perceived trauma ratings. Hence, there is reason to argue that people differ in their readiness to perceive a situation as traumatic. However, the association between self-reported dissociation and the perception of 'trauma' is not quite clear-cut.

  8. Radiative capture versus Coulomb dissociation

    International Nuclear Information System (INIS)

    Esbensen, H.; Physics

    2006-01-01

    Measurements of the Coulomb dissociation of 8 B have been used to infer the rate of the inverse radiative proton capture on 7 Be. The analysis is usually based on the assumptions that the two processes are related by detailed balance and described by E1 transitions. However, there are corrections to this relation. The Coulomb form factors for the two processes, for example, are not identical. There are also E2 transitions and higher-order effects in the Coulomb dissociation, and the nuclear induced breakup cannot always be ignored. While adding first-order E2 transitions enhances the decay energy spectrum, the other mechanisms cause a suppression at low relative energies. The net result may accidentally be close to the conventional first-order E1 calculation, but there are differences which cannot be ignored if accuracies of 10% or better are needed

  9. Radiative Capture versus Coulomb Dissociation

    International Nuclear Information System (INIS)

    Esbensen, Henning

    2006-01-01

    Measurements of the Coulomb dissociation of 8B have been used to infer the rate of the inverse radiative proton capture on 7Be. The analysis is usually based on the assumptions that the two processes are related by detailed balance and described by E1 transitions. However, there are corrections to this relation. The Coulomb form factors for the two processes, for example, are not identical. There are also E2 transitions and higher-order effects in the Coulomb dissociation, and the nuclear induced breakup cannot always be ignored. While adding first-order E2 transitions enhances the decay energy spectrum, the other mechanisms cause a suppression at low relative energies. The net result may accidentally be close to the conventional first-order E1 calculation, but there are differences which cannot be ignored if accuracies of 10% or better are needed

  10. Hydrogen dissociation on metal surfaces

    OpenAIRE

    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 processes often approximations need to be made in order to keep the computational cost feasible, such as fixing the surface atoms in place, rather than allowing them to vibrate. In this work, seve...

  11. Dissociative attachment to lithium dimers

    International Nuclear Information System (INIS)

    Wadehra, J.M.

    1987-01-01

    The cross sections and the rates of production of negative ions of atomic lithium by the process of dissociative electron attachment to lithium dimers are obtained by using the resonant scattering theory. Both the cross sections as well as the rates of attachment are enhanced if the lithium molecule is initially vibrationally excited. General expressions for approximately obtaining the rates of electron attachment to any vibrational level of Li 2 are presented

  12. Paraphilia from a dissociative perspective.

    Science.gov (United States)

    Ross, Colin A

    2008-12-01

    A dissociative structural model of the psyche can account for a wide range of symptoms across many DSM-IV categories, including sexual compulsions and addictions. The model leads to a distinct overall plan of treatment and a set of operationalized interventions aimed at integration of the self, rather than suppression of impulses. The model could be tested first in epidemiological studies and later in treatment outcome studies.

  13. Autonoesis and dissociative identity disorder.

    Science.gov (United States)

    Morton, John

    2018-01-01

    Dissociative identity disorder is characterised by the presence in one individual of two or more alternative personality states (alters). For such individuals, the memory representation of a particular event can have full episodic, autonoetic status for one alter, while having the status of knowledge or even being inaccessible to a second alter. This phenomenon appears to create difficulties for a purely representational theory and is presented to Mahr & Csibra (M&C) for their consideration.

  14. [Clinical Handling of Patients with Dissociative Disorders].

    Science.gov (United States)

    Okano, Kenichiro

    2015-01-01

    This paper discusses the way informed psychiatrists are expected to handle dissociative patients in clinical situations, with a specific focus on dissociative identity disorders and dissociative fugue. On the initial interview with dissociative patients, information on their history of trauma and any nascent dissociative symptoms in their childhood should be carefully obtained. Their level of stress in their current life should also be assessed in order to understand their symptomatology, as well as to predict their future clinical course. A psychoeducational approach is crucial; it might be helpful to give information on dissociative disorder to these patients as well as their family members in order to promote their adherence to treatment. Regarding the symptomatology of dissociative disorders, detailed symptoms and the general clinical course are presented. It was stressed that dissociative identity disorder and dissociative fugue, the most high-profile dissociative disorders, are essentially different in their etiology and clinical presentation. Dissociative disorders are often confused with and misdiagnosed as psychotic disorders, such as schizophrenia. Other conditions considered in terms of the differential diagnosis include borderline personality disorder as well as temporal lobe epilepsy. Lastly, the therapeutic approach to dissociative identity disorder is discussed. Each dissociative identity should be understood as potentially representing some traumatically stressful event in the past. The therapist should be careful not to excessively promote the creation or elaboration of any dissociative identities. Three stages are proposed in the individual psychotherapeutic process. In the initial stage, a secure environment and stabilization of symptoms should be sought. The second stage consists of aiding the "host" personality to make use of other more adaptive coping skills in their life. The third stage involves coaching as well as continuous awareness of

  15. Diffractive dissociation and new quarks

    International Nuclear Information System (INIS)

    White, A.R.

    1983-04-01

    We argue that the chiral limit of QCD can be identified with the strong (diffractive dissociation) coupling limit of reggeon field theory. Critical Pomeron scaling at high energy must then be directly related to an infra-red fixed-point of massless QCD and so requires a large number of flavors. This gives a direct argument that the emergence of diffraction-peak scaling, KNO scaling etc. at anti p-p colliders are evidence of a substantial quark structure still to be discovered

  16. 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.

  17. Mirror Writing and a Dissociative Identity Disorder

    OpenAIRE

    Le, Catherine; Smith, Joyce; Cohen, Lewis

    2009-01-01

    Individuals with dissociative identity disorder (DID) have been known to show varied skills and talents as they change from one dissociative state to another. For example, case reports have described people who have changed their handedness or have spoken foreign languages during their dissociative states. During an interview with a patient with DID, a surprising talent emerged when she wrote a sentence for the Folstein Mini-Mental State Exam—mirror writing. It is not known whether her mirror...

  18. Mirror writing and a dissociative identity disorder.

    Science.gov (United States)

    Le, Catherine; Smith, Joyce; Cohen, Lewis

    2009-01-01

    Individuals with dissociative identity disorder (DID) have been known to show varied skills and talents as they change from one dissociative state to another. For example, case reports have described people who have changed their handedness or have spoken foreign languages during their dissociative states. During an interview with a patient with DID, a surprising talent emerged when she wrote a sentence for the Folstein Mini-Mental State Exam-mirror writing. It is not known whether her mirror writing had a deeper level of meaning; however, it does emphasize the idiosyncratic nature of dissociative identity disorder.

  19. Mirror Writing and a Dissociative Identity Disorder

    Directory of Open Access Journals (Sweden)

    Catherine Le

    2009-01-01

    Full Text Available Individuals with dissociative identity disorder (DID have been known to show varied skills and talents as they change from one dissociative state to another. For example, case reports have described people who have changed their handedness or have spoken foreign languages during their dissociative states. During an interview with a patient with DID, a surprising talent emerged when she wrote a sentence for the Folstein Mini-Mental State Exam—mirror writing. It is not known whether her mirror writing had a deeper level of meaning; however, it does emphasize the idiosyncratic nature of dissociative identity disorder.

  20. Dissociative identity disorder: Medicolegal challenges.

    Science.gov (United States)

    Farrell, Helen M

    2011-01-01

    Persons with dissociative identity disorder (DID) often present in the criminal justice system rather than the mental health system and perplex experts in both professions. DID is a controversial diagnosis with important medicolegal implications. Defendants have claimed that they committed serious crimes, including rape or murder, while they were in a dissociated state. Asserting that their alter personality committed the bad act, defendants have pleaded not guilty by reason of insanity (NGRI). In such instances, forensic experts are asked to assess the defendant for DID and provide testimony in court. Debate continues over whether DID truly exists, whether expert testimony should be allowed into evidence, and whether it should exculpate defendants for their criminal acts. This article reviews historical and theoretical perspectives on DID, presents cases that illustrate the legal implications and controversies of raising an insanity defense based on multiple personalities, and examines the role of forensic experts asked to comment on DID with the goal of assisting clinicians in the medicolegal assessment of DID in relation to crimes.

  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. From dissociation to trauma? Individual differences in dissociation as predictor of 'trauma' perception

    NARCIS (Netherlands)

    Rassin, Eric; van Rootselaar, Anne-Fleur

    2006-01-01

    In clinical literature, dissociative complaints are generally considered to be the result of traumatic experiences. However, it has been argued that dissociative complaints, in turn, may indulge over-reporting of traumatic experiences. Hence, correlations between dissociation and self-reported

  3. 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.

  4. 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.

  5. Coulomb dissociation of N-20,N-21

    NARCIS (Netherlands)

    Roeder, Marko; Adachi, Tatsuya; Aksyutina, Yulia; Alcantara, Juan; Altstadt, Sebastian; Alvarez-Pol, Hector; Ashwood, Nicholas; Atar, Leyla; Aumann, Thomas; Avdeichikov, Vladimir; Barr, M.; Beceiro, Saul; Bemmerer, Daniel; Benlliure, Jose; Bertulani, Carlos; Boretzky, Konstanze; Borge, Maria J. G.; Burgunder, G.; Caamano, Manuel; Caesar, Christoph; Casarejos, Enrique; Catford, Wilton; Cederkall, Joakim; Chakraborty, S.; Chartier, Marielle; Chulkov, Leonid; Cortina-Gil, Dolores; Crespo, Raquel; Pramanik, Ushasi Datta; Diaz-Fernandez, Paloma; Dillmann, Iris; Elekes, Zoltan; Enders, Joachim; Ershova, Olga; Estrade, A.; Farinon, F.; Fraile, Luis M.; Freer, Martin; Freudenberger, M.; Fynbo, Hans; Galaviz, Daniel; Geissel, Hans; Gernhaeuser, Roman; Goebel, Kathrin; Golubev, Pavel; Diaz, D. Gonzalez; Hagdahl, Julius; Heftrich, Tanja; Heil, Michael; Heine, Marcel; Heinz, Andreas; Henriques, Ana; Holl, Matthias; Ickert, G.; Ignatov, Alexander; Jakobsson, Bo; Johansson, Hakan; Jonson, Bjorn; Kalantar-Nayestanaki, Nasser; Kanungo, Rituparna; Kelic-Heil, Aleksandra; Knoebel, Ronja; Kroell, Thorsten; Kruecken, Reiner; Kurcewicz, J.; Kurz, Nikolaus; Labiche, Marc; Langer, Christoph; Le Bleis, Tudi; Lemmon, Roy; Lepyoshkina, Olga; Lindberg, Simon; Machado, Jorge; Marganiec, Justyna; Mostazo Caro, Magdalena; Movsesyan, Alina; Najafi, Mohammad Ali; Nilsson, Thomas; Nociforo, Chiara; Panin, Valerii; Paschalis, Stefanos; Perea, Angel; Petri, Marina; Pietri, S.; Plag, Ralf; Prochazka, A.; Rahaman, Md. Anisur; Rastrepina, Ganna; Reifarth, Rene; Ribeiro, Guillermo; Ricciardi, M. Valentina; Rigollet, Catherine; Riisager, Karsten; Rossi, Dominic; del Rio Saez, Jose Sanchez; Savran, Deniz; Scheit, Heiko; Simon, Haik; Sorlin, Olivier; Stoica, V.; Streicher, Branislav; Taylor, Jon; Tengblad, Olof; Terashima, Satoru; Thies, Ronja; Togano, Yasuhiro; Uberseder, Ethan; Van de Walle, J.; Velho, Paulo; Volkov, Vasily; Wagner, Andreas; Wamers, Felix; Weick, Helmut; Weigand, Mario; Wheldon, Carl; Wilson, G.; Wimmer, Christine; Winfield, J. S.; Woods, Philip; Yakorev, Dmitry; Zhukov, Mikhail; Zilges, Andreas; Zuber, Kai

    2016-01-01

    Neutron-rich light nuclei and their reactions play an important role in the creation of chemical elements. Here, data from a Coulomb dissociation experiment on N-20,N-21 are reported. Relativistic N-20,N-21 ions impinged on a lead target and the Coulomb dissociation cross section was determined in a

  6. 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.

  7. Dissociation and the Development of Psychopathology.

    Science.gov (United States)

    Putnam, Frank W.; Trickett, Penelope K.

    This paper reviews the research on dissociation and the development of psychopathology in children and adolescents. Definitions and dimensions of dissociation are addressed, noting its range from normative daydreaming to the extremes found in individuals with multiple personality disorder. Memory dysfunctions, disturbances of identity, passive…

  8. Molecular dissociation in dilute gas

    Science.gov (United States)

    Renfrow, S. N.; Duggan, J. L.; McDaniel, F. D.

    1999-06-01

    The charge state distributions (CSD) produced during molecular dissociation are important to both Trace Element Accelerator Mass Spectrometry (TEAMS) and the ion implantation industry. The CSD of 1.3-1.7 MeV SiN+, SiMg+, SiMn+, and SiZn+ molecules have been measured for elements that do not form atomic negative ions (N, Mg, Mn, and Zn) using a NEC Tandem Pelletron accelerator. The molecules were produced in a Cs sputter negative ion source, accelerated, magnetically analyzed, and then passed through an N2 gas cell. The neutral and charged breakups where analyzed using an electrostatic deflector and measured with particle detectors. Equilibrium CSD were determined and comparisons made between molecular and atomic ion data.

  9. The (B)link Between Creativity and Dopamine: Spontaneous Eye Blink Rates Predict and Dissociate Divergent and Convergent Thinking

    Science.gov (United States)

    Chermahini, Soghra Akbari; Hommel, Bernhard

    2010-01-01

    Human creativity has been claimed to rely on the neurotransmitter dopamine, but evidence is still sparse. We studied whether individual performance (N=117) in divergent thinking (alternative uses task) and convergent thinking (remote association task) can be predicted by the individual spontaneous eye blink rate (EBR), a clinical marker of…

  10. 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

  11. 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

  12. 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.

  13. Psychotherapy and Pharmacotherapy for Patients with Dissociative Identity Disorder

    OpenAIRE

    Gentile, Julie P.; Dillon, Kristy S.; Gillig, Paulette Marie

    2013-01-01

    There is a wide variety of what have been called “dissociative disorders,” including dissociative amnesia, dissociative fugue, depersonalization disorder, dissociative identity disorder, and forms of dissociative disorder not otherwise specified. Some of these diagnoses, particularly dissociative identity disorder, are controversial and have been questioned by many clinicians over the years. The disorders may be under-diagnosed or misdiagnosed, but many persons who have experienced trauma rep...

  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. From state dissociation to status dissociatus.

    Science.gov (United States)

    Antelmi, Elena; Ferri, Raffaele; Iranzo, Alex; Arnulf, Isabelle; Dauvilliers, Yves; Bhatia, Kailash P; Liguori, Rocco; Schenck, Carlos H; Plazzi, Giuseppe

    2016-08-01

    The states of being are conventionally defined by the simultaneous occurrence of behavioral, neurophysiological and autonomic descriptors. State dissociation disorders are due to the intrusion of features typical of a different state into an ongoing state. Disorders related to these conditions are classified according to the ongoing main state and comprise: 1) Dissociation from prevailing wakefulness as seen in hypnagogic or hypnopompic hallucinations, automatic behaviors, sleep drunkenness, cataplexy and sleep paralysis 2) Dissociation from rapid eye movement (REM) sleep as seen in REM sleep behavior disorder and lucid dreaming and 3) Dissociation from NREM sleep as seen in the disorders of arousal. The extreme expression of states dissociation is characterized by the asynchronous occurrence of the various components of the different states that prevents the recognition of any state of being. This condition has been named status dissociatus. According to the underlying disorders/diseases and to their severity, among status dissociatus we may recognize disorders in which such an extreme dissociation occurs only at night time or intermittently (i.e., autoimmune encephalopathies, narcolepsy type 1 and IgLON5 parasomnia), and others in which it occurs nearly continuously with complete loss of any conventionally defined state of being, and of the circadian pattern (agrypnia excitata). Here, we render a comprehensive review of all diseases/disorders associated with state dissociation and status dissociatus and propose a critical classification of this complex scenario. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. 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

  17. 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.

  18. Dissociative recombination of molecular ions H2+

    International Nuclear Information System (INIS)

    Abarenov, A.V.; Marchenko, V.S.

    1989-01-01

    The total cross sections of dissociation and dissociative recombination of slow electrons and molecular ions H 2 + have been calculated in terms of the quasiclassical and dipole approximations. In the calculations allowance was made for the quantum nature of vibrational motion of heavy particles and presence of autoionization of divergence states of the H 2 (Σ u , nl) molecules. It is shown that the H 2 + ion dissociation cross sections are dominant in increase of the electron energy in the ε >or approx. 2-3 eV region for H 2 + (v) ion distribution over the vibrational levels characteristic for the beam experiments. 15 refs.; 5 figs

  19. Dissociative identity disorder: a controversial diagnosis.

    Science.gov (United States)

    Gillig, Paulette Marie

    2009-03-01

    A brief description of the controversies surrounding the diagnosis of dissociative identity disorder is presented, followed by a discussion of the proposed similarities and differences between dissociative identity disorder and borderline personality disorder. The phenomenon of autohypnosis in the context of early childhood sexual trauma and disordered attachment is discussed, as is the meaning of alters or alternate personalities. The author describes recent neurosciences research that may relate the symptoms of dissociative identity disorder to demonstrable disordered attention and memory processes. A clinical description of a typical patient presentation is included, plus some recommendations for approaches to treatment.

  20. How Do We Assess Dissociation in Treatment Seeking Refugees in the West?

    DEFF Research Database (Denmark)

    Palic, Sabina; Elklit, Ask; Armour, Cherie

    Bosnian treatment seeking refugees with the dissociation subscale of the Structured Interview for Disorders of Extreme Stress (SIDES-D), the self-report version of the SIDES-D (SIDES-D-SR), the Dissociative Experiences Scale (DES), and the DES-Taxon. The DES correlated strongly with the SIDES......Not enough attention is paid to dissociation in treatment of traumatized refugees in western countries. Knowledge about the assessment, the extent, and the content of dissociation in this group is lacking. An evaluation of measures and description of dissociative symptoms was carried out in 86...... dissociation. The most common dissociative symptoms in treatement seeking refugees are discussed, and characteristics of the presumably “dissociated” pre- and post-war personality, which was spontanously observed during the clnical interviews...

  1. The cognitive psychology of dissociative states.

    Science.gov (United States)

    Brown, Richard J

    2002-08-01

    A number of theoretical models have identified dissociation as a possible cognitive mechanism underlying medically unexplained symptoms (''hysteria''). A review of research and theory in this area indicates that the dissociation concept is a useful explanation of this phenomenon. However, existing models of dissociation have a number of explanatory shortcomings. This article describes a recent model of unexplained illness that aims to extend the dissociation concept by reference to research and theory from contemporary cognitive psychology. According to this view, unexplained symptoms should be regarded as disturbances of consciousness and behavioural control, resulting from the chronic activation of stored symptom representations within memory. This process is driven by the repeated reallocation of high-level attention on to symptom representations. The model offers a fresh perspective on the nature of unexplained symptoms, providing an explicit account of the factors involved in the creation and maintenance of this phenomenon.

  2. 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.

  3. 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

  4. Dissociation in eating disorders: relationship between dissociative experiences and binge-eating episodes.

    Science.gov (United States)

    La Mela, Carmelo; Maglietta, Marzio; Castellini, Giovanni; Amoroso, Luca; Lucarelli, Stefano

    2010-01-01

    Several findings support the hypothesis that there is a relationship between dissociation and eating disorders (EDs). The aims of this study were as follows: (1) to assess whether ED patients show a higher level of dissociation than healthy control (HC) individuals or psychiatric control patients with anxiety and mood disorders and (2) to investigate the effects of dissociation on ED symptoms, specifically binge eating behavior. Fifty-four ED patients, 56 anxiety and mood disorders control patients, and 39 HC individuals completed the Eating Disorder Examination Questionnaire and the Dissociation Questionnaire. Each participant was asked about the number of binge eating episodes he or she had experienced in the past 4 weeks. The ED patients had higher levels of dissociation than both the psychiatric control group and the HC group. In the ED group, the number of binge episodes was related to the level of dissociation. Dissociative experiences are relevant in EDs, and binge eating is related to dissociation. In patients affected by the core psychopathologic beliefs of EDs (overevaluation of shape and weight), dissociation may allow an individual to initiate binging behavior, thus decreasing self-awareness and negative emotional states, without having to deal with the long-term consequences of their actions. Copyright 2010 Elsevier Inc. All rights reserved.

  5. Fast kinetics of calcium dissociation from calsequestrin

    Directory of Open Access Journals (Sweden)

    MARIANELA BELTRÁN

    2006-01-01

    Full Text Available We measured the kinetics of calcium dissociation from calsequestrin in solution or forming part of isolated junctional sarcoplasmic reticulum membranes by mixing calsequestrin equilibrated with calcium with calcium-free solutions in a stopped-flow system. In parallel, we measured the kinetics of the intrinsic fluorescence changes that take place following calcium dissociation from calsequestrin. We found that at 25ºC calcium dissociation was 10-fold faster for calsequestrin attached to junctional membranes (k = 109 s-1 than in solution. These results imply that calcium dissociation from calsequestrin in vivo is not rate limiting during excitation-contraction coupling. In addition, we found that the intrinsic fluorescence decrease for calsequestrin in solution or forming part of junctional membranes was significantly slower than the rates of calcium dissociation. The kinetics of intrinsic fluorescence changes had two components for calsequestrin associated to junctional membranes and only one for calsequestrin in solution; the faster component was 8-fold faster (k = 54.1 s-1 than the slower component (k = 6.9 s-1, which had the same k value as for calsequestrin in solution. These combined results suggest that the presence of calsequestrin at high concentrations in a restricted space, such as when bound to the junctional membrane, accelerates calcium dissociation and the resulting structural changes, presumably as a result of cooperative molecular interactions.

  6. New-onset dissociative disorder after electroconvulsive therapy.

    Science.gov (United States)

    Zaidner, Eduardo; Sewell, R Andrew; Murray, Evan; Schiller, Allen; Price, Bruce H; Cunningham, Miles G

    2010-09-01

    Electroconvulsive therapy (ECT) is an exceptionally effective treatment for a number of psychiatric conditions; however, a common adverse effect is temporary cognitive impairment, especially memory loss. The dissociative disorders also involve disturbances of memory, as well as consciousness and personal identity, but are rarely iatrogenic. We report a case in which dissociative symptoms developed after ECT. A 51-year-old woman with hypothyroidism, migraine headaches, bipolar disorder, and anorexia by history was admitted for worsening depression with suicidal ideation. After a course of 7 right-sided ECT treatments, she experienced remarkable personality change, claiming that it was 1976 and behaving as though she was 30 years younger. Neuropsychological tests were normal, and her memory and former personality spontaneously returned 2 weeks later. This case illustrates that such events may be seen in patients with certain psychiatric profiles, and further studies are needed to determine the risk factors for the occurrence of dissociative episodes after ECT.

  7. Dissociative Spectrum Disorders in the Primary Care Setting

    OpenAIRE

    Elmore, James L.

    2000-01-01

    Dissociative disorders have a lifetime prevalence of about 10%. Dissociative symptoms may occur in acute stress disorder, posttraumatic stress disorder, somatization disorder, substance abuse, trance and possession trance, Ganser's syndrome, and dissociative identity disorder, as well as in mood disorders, psychoses, and personality disorders. Dissociative symptoms and disorders are observed frequently among patients attending our rural South Carolina community mental health center. Given the...

  8. 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

  9. 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...

  10. Dissociation of deuteron, 6He and 11Be from Coulomb dissociation ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 70; Issue 5. Dissociation of ... Diffraction dissociation; Coulomb effect; post-acceleration phenomenon; momentum distribution; bremsstrahlung integral; halo structure. ... Physics Department, Vivekananda College, 269, Diamond Harvour Road, Kolkata 700 063, India ...

  11. Isotope separation by photoselective dissociative electron

    International Nuclear Information System (INIS)

    Stevens, C.G.

    1978-01-01

    A method of separating isotopes based on photoselective electron capture dissociation of molecules having an electron capture cross section dependence on the vibrational state of the molecule is described. A molecular isotope source material is irradiated to selectively excite those molecules containing a desired isotope to a predetermined vibrational state having associated therewith an electron capture energy region substantially non-overlapping with the electron capture energy ranges associated with the lowest vibration states of the molecules. The isotope source is also subjected to electrons having an energy corresponding to the non-overlapping electron capture region whereby the selectively excited molecules preferentially capture electrons and dissociate into negative ions and neutrals. The desired isotope may be in the negative ion product or in the neutral product depending upon the mechanism of dissociation of the particular isotope source used. The dissociation product enriched in the desired isotope is then separated from the reaction system by conventional means. Specifically, 235 UF 6 is separated from a UF 6 mixture by selective excitation followed by dissociative electron capture into 235 UF 5 - and F

  12. Psychotherapy and pharmacotherapy for patients with dissociative identity disorder.

    Science.gov (United States)

    Gentile, Julie P; Dillon, Kristy S; Gillig, Paulette Marie

    2013-02-01

    There is a wide variety of what have been called "dissociative disorders," including dissociative amnesia, dissociative fugue, depersonalization disorder, dissociative identity disorder, and forms of dissociative disorder not otherwise specified. Some of these diagnoses, particularly dissociative identity disorder, are controversial and have been questioned by many clinicians over the years. The disorders may be under-diagnosed or misdiagnosed, but many persons who have experienced trauma report "dissociative" symptoms. Prevalence of dissociative disorders is unknown, but current estimates are higher than previously thought. This paper reviews clinical, phenomenological, and epidemiological data regarding diagnosis in general, and illustrates possible treatment interventions for dissociative identity disorder, with a focus on psychotherapy interventions and a review of current psychopharmacology recommendations as part of a comprehensive multidisciplinary treatment plan.

  13. 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.

  14. Dissociation mechanisms of photoexcited molecular ions

    CERN Document Server

    Inglis, L C

    2003-01-01

    Photoionisation of gas phase molecules, in the energy range 8 - 40 eV, and the subsequent dissociation mechanisms have been investigated using threshold photoelectron spectroscopy and ion time-of-flight mass spectrometry. The excitation source used was monochromatic radiation, delivered by station 3.2 at the Daresbury Laboratory Synchrotron Radiation Source. These two techniques have also been combined in threshold photoelectron-photoion coincidence experiments, in order to record coincidence time-of-flight mass spectra and thereby determine breakdown curves. Such curves display the ion fragmentation as a function of internal energy. In addition, computer modelling techniques have been employed to gain some understanding of the unimolecular dissociations of energy selected molecular ions by establishing theoretical breakdown graphs, appearance energies, fragmentation pathways and dissociation rates. Ab initio quantum chemistry calculations have been carried out, generating ionisation and appearance energies, ...

  15. Dissociation in virtual reality: depersonalization and derealization

    Science.gov (United States)

    Garvey, Gregory P.

    2010-01-01

    This paper looks at virtual worlds such as Second Life7 (SL) as possible incubators of dissociation disorders as classified by the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition3 (also known as the DSM-IV). Depersonalization is where "a person feels that he or she has changed in some way or is somehow unreal." Derealization when "the same beliefs are held about one's surroundings." Dissociative Identity Disorder (DID), previously known as multiple personality disorder fits users of Second Life who adopt "in-world" avatars and in effect, enact multiple distinct identities or personalities (known as alter egos or alters). Select questions from the Structured Clinical Interview for Depersonalization (SCI-DER)8 will be discussed as they might apply to the user's experience in Second Life. Finally I would like to consider the hypothesis that rather than a pathological disorder, dissociation is a normal response to the "artificial reality" of Second Life.

  16. Dissociative amnesia: a case with management challenges

    Directory of Open Access Journals (Sweden)

    Priti Singh

    2015-07-01

    Full Text Available A case of dissociative amnesia with regressed behaviour was diagnosed applying the existing criteria for dissociative disorder in the tenth revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10. Though there are number of cases of such condition, but when coupled with regressed behaviour it adds to new dimension in the management. An applied strategy in lines with both pharmacological and non pharmacological was used, and we found that it helped our patient to gradually improve her behaviour. This is one of the few cases reported and we hope more such cases should be reported in understanding the psychopathology.

  17. Coulomb dissociation of $^{20,21}$N

    OpenAIRE

    Röder, Marko; Adachi, Tatsuya; Aksyutina, Yulia; Alcantara, Juan; Altstadt, Sebastian; Alvarez-Pol, Hector; Ashwood, Nicholas; Atar, Leyla; Aumann, Thomas; Avdeichikov, Vladimir; Barr, M.; Beceiro, Saul; Bemmerer, Daniel; Benlliure, Jose; Bertulani, Carlos

    2016-01-01

    Neutron-rich light nuclei and their reactions play an important role for the creation of chemical elements. Here, data from a Coulomb dissociation experiment on $^{20,21}$N are reported. Relativistic $^{20,21}$N ions impinged on a lead target and the Coulomb dissociation cross section was determined in a kinematically complete experiment. Using the detailed balance theorem, the $^{19}\\mathrm{N}(\\mathrm{n},\\gamma)^{20}\\mathrm{N}$ and $^{20}\\mathrm{N}(\\mathrm{n},\\gamma)^{21}\\mathrm{N}$ excitati...

  18. Coulomb dissociation of N 20,21

    OpenAIRE

    Röder, Marko; Adachi, Tatsuya; Aksyutina, Yulia; Alcantara, Juan; Altstadt, Sebastian; Alvarez-Pol, Hector; Ashwood, Nicholas; Atar, Leyla; Aumann, Thomas; Avdeichikov, Vladimir; Barr, M.; Beceiro, Saul; Bemmerer, Daniel; Benlliure, Jose; Bertulani, Carlos

    2016-01-01

    Neutron-rich light nuclei and their reactions play an important role in the creation of chemical elements. Here, data from a Coulomb dissociation experiment on N20,21 are reported. Relativistic N20,21 ions impinged on a lead target and the Coulomb dissociation cross section was determined in a kinematically complete experiment. Using the detailed balance theorem, the N19(n,γ)N20 and N20(n,γ)N21 excitation functions and thermonuclear reaction rates have been determined. The N19(n,γ)N20 rate is...

  19. Cognitive behavioral hypnotherapy for dissociative disorders.

    Science.gov (United States)

    Fine, Catherine G

    2012-04-01

    Dissociative disorders (DD) prevail as sequelae to overwhelming experiences in childhood. These readily formed post-traumatic responses and trance states develop in high hypnotizable subjects whose dysregulations become organized into ego states. A cognitive behavioral hypnotherapeutic treatment model will effectively contain, explore, metabolize, and resolve these life-endangering conditions. This article will detail the cognitive hypnotic world of DD patients, the relational spaces of the ego states, and the triphasic treatment mode to successfully resolve the dissociative pathology. Structured and phase appropriate hypnotic interventions will be described.

  20. Visuomotor Dissociation in Cerebral Scaling of Size

    NARCIS (Netherlands)

    Potgieser, Adriaan R. E.; de Jong, Bauke M.

    2016-01-01

    Estimating size and distance is crucial in effective visuomotor control. The concept of an internal coordinate system implies that visual and motor size parameters are scaled onto a common template. To dissociate perceptual and motor components in such scaling, we performed an fMRI experiment in

  1. Dissociative electron attachment to ozone: rate constant

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  2. From dissociated hegemony towards embedded hegemony

    NARCIS (Netherlands)

    Gaay Fortman, B. de; Dhanrajgir, Nikhil

    2005-01-01

    An earlier paper by the second author, entitled ‘Bella Americana: Some Consequences for the International Community’ [1], dealt with the background and consequences of the American dissociation from the international legal and political order created after World War II. The current article

  3. Psychobiology of dissociation and its clinical assessment.

    Science.gov (United States)

    Ptacek, Radek; Bob, Petr; Paclt, Ivo; Pavlat, Josef; Jasova, Denisa; Zvolsky, Petr; Raboch, Jiri

    2007-04-01

    Dissociation is often defined as partial or total disconnection between memories of the past, awareness of identity and of immediate sensations, and control of bodily movements, often resulting from traumatic experiences, intolerable problems, or disturbed relationships. This type of reaction to a psychological and/or physical trauma has often various neurobiological consequences and its clinical assessment has received enormous interest in recent psychological and neuroscience research. Psychometric parameters of the Czech version of the Dissociative Experiences Scale were tested from the viewpoints of internal consistency, validity and factor structure, using data from a sample of n=783 adults, divided into three groups (epilepsy n=243, depression n=357, norm n=183), average age 39 years, SD=13.5. Findings of this study demonstrated that reliability, validity and factor structure of the Czech version of the Dissociative Experiences Scale correspond to those of the original English version. The Czech version of the questionnaire may be considered a suitable tool for estimating subjectively experienced dissociative symptoms.

  4. Dissociations between Imagery and Language Processing.

    Science.gov (United States)

    1984-08-20

    review of the neuropsychological literature on imagery, Erlichman & Barrett (1983) discovered that in general imagery is not systematically correlated...Arteriography showed a left occipital hematoma, caused by an arteriovenous malformation (AYM). A I Imagery dissociations 5 craniotomy was performed to

  5. 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 ...

  6. Dissociative charge exchange of H2+

    International Nuclear Information System (INIS)

    Bruijn, D. de.

    1983-01-01

    This thesis is devoted to molecular dissociation, in particular the dissociation of the hydrogen molecule H 2 arising from electron capture of its ion H 2 + in a collision. Thereby the important practical question how a chemical bond can be broken is implicitly addressed. This thesis opens (chapter I) with an overview of the available experimental approaches in molecular physics. Further the simple Demkov model for NRCE is described. In chapter II a novel experimental technique for measurements on dissociative processes is introduced which combines a high efficiency with a high energy resolution. A detailed description of the techniques applied in the detector, which has a high spatial and timing resolution with 30 μm and 350 psec FWHM respectively for the detection of one particle, is given in chapter III. A semi-classical theory for NRCE in the medium energy range between a diatomic molecular ion and an atom is developed in chapter IV. The experiments on dissociative charge exchange of H 2 + with Ar, Mg, Na and Cs targets at keV energies are described in Chapter V. The predissociation of the c 3 PIsub(u)-state of H 2 populated after charge exchange of H 2 with several targets at keV energies; is the subject of chapter VI. In chapter VII, orientational oscillations in the cross section for charge exchange of H 2 + with alkali targets are discussed. The last chapter deals with predissociation of highly excited states in H 2 . (Auth.)

  7. Psychobiological characteristics of dissociative identity disorder : A symptom provocation study

    NARCIS (Netherlands)

    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.

    2006-01-01

    Background: 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.

  8. 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.

  9. Thermal dissociation behavior and dissociation enthalpies of methane-carbon dioxide mixed hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, T.H.; Kneafsey, T.J.; Rees, E.V.L.

    2011-02-15

    Replacement of methane with carbon dioxide in hydrate has been proposed as a strategy for geologic sequestration of carbon dioxide (CO{sub 2}) and/or production of methane (CH{sub 4}) from natural hydrate deposits. This replacement strategy requires a better understanding of the thermodynamic characteristics of binary mixtures of CH{sub 4} and CO{sub 2} hydrate (CH{sub 4}-CO{sub 2} mixed hydrates), as well as thermophysical property changes during gas exchange. This study explores the thermal dissociation behavior and dissociation enthalpies of CH{sub 4}-CO{sub 2} mixed hydrates. We prepared CH{sub 4}-CO{sub 2} mixed hydrate samples from two different, well-defined gas mixtures. During thermal dissociation of a CH{sub 4}-CO{sub 2} mixed hydrate sample, gas samples from the head space were periodically collected and analyzed using gas chromatography. The changes in CH{sub 4}-CO{sub 2} compositions in both the vapor phase and hydrate phase during dissociation were estimated based on the gas chromatography measurements. It was found that the CO{sub 2} concentration in the vapor phase became richer during dissociation because the initial hydrate composition contained relatively more CO{sub 2} than the vapor phase. The composition change in the vapor phase during hydrate dissociation affected the dissociation pressure and temperature; the richer CO{sub 2} in the vapor phase led to a lower dissociation pressure. Furthermore, the increase in CO{sub 2} concentration in the vapor phase enriched the hydrate in CO{sub 2}. The dissociation enthalpy of the CH{sub 4}-CO{sub 2} mixed hydrate was computed by fitting the Clausius-Clapeyron equation to the pressure-temperature (PT) trace of a dissociation test. It was observed that the dissociation enthalpy of the CH{sub 4}-CO{sub 2} mixed hydrate lays between the limiting values of pure CH{sub 4} hydrate and CO{sub 2} hydrate, increasing with the CO{sub 2} fraction in the hydrate phase.

  10. Assessment of complex dissociative disorder patients and simulated dissociation in forensic contexts.

    Science.gov (United States)

    Brand, Bethany L; Webermann, Aliya R; Frankel, A Steven

    Few assessors receive training in assessing dissociation and complex dissociative disorders (DDs). Potential differential diagnoses include anxiety, mood, psychotic, substance use, and personality disorders, as well as exaggeration and malingering. Individuals with DDs typically elevate on many clinical and validity scales on psychological tests, yet research indicates that they can be distinguished from DD simulators. Becoming informed about the testing profiles of DD individuals and DD simulators can improve the accuracy of differential diagnoses in forensic settings. In this paper, we first review the testing profiles of individuals with complex DDs and contrast them with DD simulators on assessment measures used in forensic contexts, including the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), Personality Assessment Inventory (PAI), and the Structured Inventory of Reported Symptoms (SIRS), as well as dissociation-specific measures such as the Dissociative Experiences Scale (DES) and Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D-R). We then provide recommendations for assessing complex trauma and dissociation through the aforementioned assessments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. 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.

  12. Photofragment translational spectroscopy of three body dissociations and free radicals

    Energy Technology Data Exchange (ETDEWEB)

    North, Simon William [Univ. of California, Berkeley, CA (United States)

    1995-04-01

    This dissertation describes several three-body dissociations and the photodissociation of methyl radicals studied using photofragment translational spectroscopy. The first chapter provides an introduction to three body dissociation, examines current experimental methodology, and includes a discussion on the treatment of photofragment translational spectroscopy data arising from three-body fragmentation. The ultraviolet photodissociation of azomethane into two methyl radicals and nitrogen is discussed in chapter 2. Chapter 3 describes the photodissociation of acetone at 248 nm and 193 nm. At 248 nm the translational energy release from the initial C-C bond cleavage matches the exit barrier height and a comparison with results at 266 nm suggests that T> is invariant to the available energy. A fraction of the nascent CH3CO radicals spontaneously dissociate following rotational averaging. The T> for the second C-C bond cleavage also matches the exit barrier height. At 193 nm the experimental data can be successfully fit assuming that the dynamics are analogous to those at 248 nm. A simplified model of energy partitioning which adequately describes the experimental results is discussed. Experiments on acetyl halides provide additional evidence to support the proposed acetone dissociation mechanism. A value of 17.0±1.0 kcal/mole for the barrier height, CH3CO decomposition has been determined. The photodissociation of methyl radical at 193 nm and 212.8 nm is discussed in the chapter 5. The formation of CH2(1Al) and H (2S) was the only single photon dissociation pathway observed at both wavelengths.

  13. The Contribution of Art Therapy to the Dissociative Disorders.

    Science.gov (United States)

    Murphy, Patricia S.

    1994-01-01

    Explored concepts of brain hemispheric lateralization and distinct right brain functioning in extensive dissociation by administering Dissociative Experiences Scale to 114 engineering students and 92 university drawing students. Chi-square calculation found differences in dissociative scoring levels between groups that approached significance at…

  14. The Parenting Experiences of Mothers with Dissociative Disorders.

    Science.gov (United States)

    Benjamin, Lynn R.; Benjamin, Robert; Rind, Bruce

    1998-01-01

    Presents a qualitative analysis of the experience of parenting of mothers with dissociative disorders. Using the mothers' words, describes how the five symptom areas of dissociation impeded their parenting efforts. Discusses the necessity of addressing parenting in the treatment of client-mothers with dissociative disorders. (Author/MKA)

  15. 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

  16. A DFT study of temperature dependent dissociation mechanism of ...

    Indian Academy of Sciences (India)

    Abstract. We report a Density Functional Theoretical (DFT) study of dissociation of Hydrogen Fluoride (HF) in HF(H2O)7 cluster, using B3LYP functional and empirical exchange correlation functional M06-2X along with 6-31+G(d,p) basis set. Dissociation constant, KRP, of HF dissociation and pKa values of HF in cluster.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-09

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

  18. Dissociating response systems: erasing fear from memory.

    Science.gov (United States)

    Soeter, Marieke; Kindt, Merel

    2010-07-01

    In addition to the extensive evidence in animals, we previously showed that disrupting reconsolidation by noradrenergic blockade produced amnesia for the original fear response in humans. Interestingly, the declarative memory for the fear association remained intact. These results asked for a solid replication. Moreover, given the constructive nature of memories, the intact recollection of the fear association could eventually 'rebuild' the fear memory, resulting in the spontaneous recovery of the fear response. Yet, perseverance of the amnesic effects would have substantial clinical implications, as even the most effective treatments for psychiatric disorders display high percentages of relapse. Using a differential fear conditioning procedure in humans, we replicated our previous findings by showing that administering propranolol (40mg) prior to memory reactivation eliminated the startle fear response 24h later. But most importantly, this effect persisted at one month follow-up. Notably, the propranolol manipulation not only left the declarative memory for the acquired contingency untouched, but also skin conductance discrimination. In addition, a close association between declarative knowledge and skin conductance responses was found. These findings are in line with the supposed double dissociation of fear conditioning and declarative knowledge relative to the amygdala and hippocampus in humans. They support the view that skin conductance conditioning primarily reflects contingency learning, whereas the startle response is a rather specific measure of fear. Furthermore, the results indicate the absence of a causal link between the actual knowledge of a fear association and its fear response, even though they often operate in parallel. Interventions targeting the amygdalar fear memory may be essential in specifically and persistently dampening the emotional impact of fear. From a clinical and ethical perspective, disrupting reconsolidation points to promising

  19. Comparing the symptoms and mechanisms of "dissociation" in dissociative identity disorder and borderline personality disorder.

    Science.gov (United States)

    Laddis, Andreas; Dell, Paul F; Korzekwa, Marilyn

    2017-01-01

    A total of 75 patients were diagnosed with the Structured Clinical Interview for DSM-IV Dissociative Disorders-Revised as having dissociative identity disorder (DID), and 100 patients were diagnosed with the Structured Interview for DSM-IV Personality as having borderline personality disorder (BPD). Both groups were administered the Multidimensional Inventory of Dissociation (MID). DID patients had significantly higher MID scores than BPD patients, different distributions of MID scores, and different MID subscale profiles in 3 ranges of MID scores (0-15, 15-30, 30-45). The core MID symptoms-exhibited at all ranges of MID scores-for DID patients (the presence of alters, identity confusion, and memory problems) and BPD patients (flashbacks, identity confusion, and memory problems) were ostensibly similar but were considered to be mostly produced by different underlying processes. Multiple regression analyses showed that the core MID symptoms of DID patients had different predictors than did the core MID symptoms of BPD patients. Alter identities seemed to generate most-but not all-dissociative phenomena in DID patients, whereas only the 24% highest scoring BPD patients (MID ≥45) seemed to manifest alter-driven dissociative experiences. Most BPD dissociative experiences appeared to be due to 5 other mechanisms: (a) BPD-specific, stress-driven, rapid shifts of self-state; (b and c) nondefensive disruptions of the framework of perceptual organization with or without an accompanying BPD-specific, dissociation-like disintegration of affective/neurocognitive functioning; (d) a defensive distancing or detachment from distress (i.e., simple depersonalization); and (e) Allen, Console, and Lewis's (1999) severe absorptive detachment.

  20. Dissociative Disorders: Between Neurosis and Psychosis

    Science.gov (United States)

    Devillé, C.; Moeglin, C.; Sentissi, O.

    2014-01-01

    Dissociative disorders are a set of disorders defined by a disturbance affecting functions that are normally integrated with a prevalence of 2.4 percent in industrialised countries. These disorders are often poorly diagnosed or misdiagnosed because of sharing common clinical features with psychotic disorders, but requiring a very different trajectory of care. Repeated clinical situations in a crisis centre in Geneva provided us with a critical overview of current evidence of knowledge in clinical and etiopathological field about dissociative disorders. Because of their multiple expressions and the overlap with psychotic disorders, we focused on the clinical aspects using three different situations to better understand their specificity and to extend our thinking to the relevance of terms “neurosis” and “psychosis.” Finally, we hope that this work might help physicians and psychiatrists to become more aware of this complex set of disorders while making a diagnosis. PMID:25405051

  1. 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.

  2. Dissociative Disorders: Between Neurosis and Psychosis

    Directory of Open Access Journals (Sweden)

    C. Devillé

    2014-01-01

    Full Text Available Dissociative disorders are a set of disorders defined by a disturbance affecting functions that are normally integrated with a prevalence of 2.4 percent in industrialised countries. These disorders are often poorly diagnosed or misdiagnosed because of sharing common clinical features with psychotic disorders, but requiring a very different trajectory of care. Repeated clinical situations in a crisis centre in Geneva provided us with a critical overview of current evidence of knowledge in clinical and etiopathological field about dissociative disorders. Because of their multiple expressions and the overlap with psychotic disorders, we focused on the clinical aspects using three different situations to better understand their specificity and to extend our thinking to the relevance of terms “neurosis” and “psychosis.” Finally, we hope that this work might help physicians and psychiatrists to become more aware of this complex set of disorders while making a diagnosis.

  3. 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

  4. Dissociations between developmental dyslexias and attention deficits

    OpenAIRE

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

    2015-01-01

    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 o...

  5. Tissue Dissociation Enzyme Neutral Protease Assessment

    OpenAIRE

    Breite, A.G.; Dwulet, F.E.; McCarthy, R.C.

    2010-01-01

    Neutral proteases, essential components of purified tissue dissociation enzymes required for successful human islet isolation, show variable activities and effects of substrate on their activities. Initially we used a spectrophotometric endpoint assay with azocasein substrate to measure neutral protease activity. After critical review of the results, we observed these data to be inconsistent and not correlating expected differences in specific activities between thermolysin and Bacillus polym...

  6. Acid dissociation characteristics of humic acids

    International Nuclear Information System (INIS)

    Tochiyama, Osamu; Sakakibara, Tetsuro; Inoue, Yasushi

    1995-01-01

    Based on the results from potentiometric titrations carried out on polyacrylic acid and some commercially available humic acids, the equation for the proton dissociation of weak polymeric acids is proposed to be K app (H + )α/(1-α) = K 1/2 {(1-α)/α}((Na + )/(Na + ) s ), where α is the degree of dissociation, K 1/2 is the dissociation constant at α = 1/2, and the brackets with subscript s denote the concentration at the surface of the polymer. This equation has been derived on the assumptions: (i) Each polymer molecule is a polybasic acid (H N R N ) having different acidic sites with K values from K 1 to K N . (ii) Binding energies of protons on these sites are all equal. (iii) The ratios of the dissociation constants of H N-i R N i- and H N-j R N j- is expressed by K i /K j = {(N-i+1)/i}/{(N-j+1)/j} since the probabilities to release or bind a proton are proportional to the numbers of protons or numbers of available anionic sites on the polymer. (iv) The effective concentration of protons at the surface of the polymer ((H + ) s ) is related by (H + ) s /(H + ) = (Na + ) s /(Na + ), where (Na + ) s can be estimated by the relation, (Na + ) s = (Cl - ) s + (R - ) s (where (R - ) s Σi(H N-i R N i- )). This leads to (Na + ) s ≅ (Cl - ) s , which in turn leads to (Na + ) s ≅ (Na + ) at high ionic strength and (Na + ) s ≅ (R - ) s = C R α at low ionic strength. (author)

  7. Selective dissociation in dication-molecule reactions

    Czech Academy of Sciences Publication Activity Database

    Parkes, M. A.; Lockyear, J. F.; Price, S. D.; Schröder, Detlef; Roithová, J.; Herman, Zdeněk

    2010-01-01

    Roč. 12, č. 23 (2010), s. 6233-6243 ISSN 1463-9076 R&D Projects: GA ČR GA203/09/1223 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z40400503 Keywords : coincidence methods * dications * dissociation * electron transfer * energy partitioning Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.454, year: 2010

  8. 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.)

  9. Dressing effect in multiphoton unimolecular dissociation

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Diaz, P.F.; Garcia-Fernandez, P.

    1986-03-01

    On the basis of a quantum-statistical model recently discussed, we deal in this paper with the perturbations induced by the intense field of a CO/sub 2/ laser on the levels of the vibrational pattern of a molecule undergoing multiphoton unimolecular dissociation. This perturbational correction is investigated by using a displacement operator technique and the results are interpreted according to the statistical model.

  10. Dissociation of recombinant prion autocatalysis from infectivity

    OpenAIRE

    Noble, Geoffrey P; Supattapone, Surachai

    2015-01-01

    Within the mammalian prion field, the existence of recombinant prion protein (PrP) conformers with self-replicating (ie. autocatalytic) activity in vitro but little to no infectious activity in vivo challenges a key prediction of the protein-only hypothesis of prion replication – that autocatalytic PrP conformers should be infectious. To understand this dissociation of autocatalysis from infectivity, we recently performed a structural and functional comparison between a highly infectious and ...

  11. Sulfur isotope separation by dissociative electron attachment

    International Nuclear Information System (INIS)

    Allen, J.E. Jr.

    1976-01-01

    A new method is proposed for isotope separation in polyatomic molecules. In this method a laser is tuned to selectively excite a vibration mode of the molecules which contain the isotope to be removed. Before deactivation can occur, an electron is attached, resulting in an excited negative ion. Under the proper conditions this ion may dissociate, producing fragments which can be removed chemically. This technique is particularly suited to isotope separation in SF 6 . Potential energy curves are developed for this molecule to aid in explaining the mechanism of dissociative electron attachment. These curves incorporate much of the information known about attachment of electrons to SF 6 and represent an improvement over previously published curves. A rough estimate of the effectiveness of this method is made, based upon the temperature-dependent branching ratio for SF 5 - and SF 6 - . The calculations indicate that the fractional 34 S content in a sample of processed SF 6 may increase 4760 times the content in a natural sample. A kinetics model is presented to describe the attachment of electrons to SF 6 . Numerical solutions of the appropriate rate equations indicate that application of the proposed technique to SF 6 will require a low pressure environment and a large number of zero energy electrons. A simple theory is developed to determine threshold intensities for laser-induced dissociation on the basis of experimentally measurable quantities, the total laser power and the reaction volume. Using the focused beam method, a series of experiments performed to separate isotopes in SF 6 establishes a value of 6.0 MW/cm 2 for the threshold intensity. This eliminates dissociative electron attachment as an explanation of isotope separation by the focused beam method, but does not exclude it as a viable technique for separating isotopes

  12. 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.

  13. Psychophysiological correlates of dissociation, handedness, and hemispheric lateralization.

    Science.gov (United States)

    Ashworth, Joel; Ciorciari, Joseph; Stough, Con

    2008-05-01

    Dissociation involves a disruption of typically integrated functions including consciousness, information perception, and memory; however, dissociation may not always be of a pathologic nature. Increasingly, studies are identifying relations between inconsistent handedness, mixed hemispheric lateralization, and dissociative symptomatology in both clinical and nonclinical populations. The current study explored whether a nonclinical sample of individuals scoring high in dissociation would display an inconsistent handedness in conjunction with a left hemispheric lateralization as measured by electroencephalography. Twenty-seven participants (12 males and 15 females) aged between 20 and 59 years (M = 29.1 year, SD = 11.2 years), completed the Dissociative Experiences Scale and Waterloo Handedness Questionnaire Revised after determining laterality. As predicted, inconsistently handed participants scoring high in dissociation displayed left hemispheric lateralization across frontal, central, and parietal regions. Conversely, right lateralization was found within Delta frequency band across temporal regions. The study provides a good framework for future research investigating the neurophysiological correlates underpinning dissociative symptomatology.

  14. Dissociative style and individual differences in verbal working memory span.

    Science.gov (United States)

    de Ruiter, Michiel B; Phaf, R Hans; Elzinga, Bernet M; van Dyck, Richard

    2004-12-01

    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 dissociative style, a positive relationship was also expected between dissociative style and verbal working memory span. In a sample of 119 psychology students, it was found that the verbal span of the high-dissociative group was about half a word larger than of the medium and low-dissociative groups. It is suggested that dissociative style may be one of only very few individual differences that is directly relevant to consciousness research.

  15. Dissociative recombination of small molecular ions

    International Nuclear Information System (INIS)

    Mul, P.M.

    1981-01-01

    In this thesis an analysis is given of merged electron-ion beam experiment and work on dissociative recombination of molecular ions and electrons is described. Chapter II covers a brief introduction of the theory of dissociative recombination. In chapter III, a description is given of the merged electron-ion beam experiment and a method is described which allows the determination of the mean angle between the electron and ion trajectories in a merged electron-ion beam experiment. In chapter IV a paper on the three dominant atmospheric diatomic ions NO + , O 2 + and N 2 + is presented and in chapter V the dissociative recombination for N 2 H + and N 2 D + is discussed. In chapter VI two papers on the polyatomic ions of the carbon-containing molecular ions are presented, and in chapter VII a letter with some results of the work presented in more detail in the chapters IV, V and VI is presented. The magnitude and the energy dependence of the cross-section measured by the merged beam technique and by other techniques is compared and discussed. (Auth.)

  16. 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)

  17. Dissociative symptoms and dissociative disorders comorbidity in obsessive compulsive disorder: Symptom screening, diagnostic tools and reflections on treatment.

    Science.gov (United States)

    Belli, Hasan

    2014-08-16

    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 experiences scale can be used for screening dissociative symptoms and detecting dissociative disorders in patients with OCD. However, a history of neglect and abuse during childhood is linked to a risk factor in the pathogenesis of dissociative psychopathology in adults. The childhood trauma questionnaire-53 and childhood trauma questionnaire-40 can be used for this purpose. Clinicians should not fail to notice the hidden dissociative symptoms and childhood traumatic experiences in OCD cases with severe symptoms that are resistant to treatment. Symptom screening and diagnostic tools used for this purpose should be known. Knowing how to treat these pathologies in patients who are diagnosed with OCD can be crucial.

  18. 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.

  19. Effects of electrostatic interactions on ligand dissociation kinetics

    Science.gov (United States)

    Erbaş, Aykut; de la Cruz, Monica Olvera; Marko, John F.

    2018-02-01

    We study unbinding of multivalent cationic ligands from oppositely charged polymeric binding sites sparsely grafted on a flat neutral substrate. Our molecular dynamics simulations are suggested by single-molecule studies of protein-DNA interactions. We consider univalent salt concentrations spanning roughly a 1000-fold range, together with various concentrations of excess ligands in solution. To reveal the ionic effects on unbinding kinetics of spontaneous and facilitated dissociation mechanisms, we treat electrostatic interactions both at a Debye-Hückel (DH) (or implicit ions, i.e., use of an electrostatic potential with a prescribed decay length) level and by the more precise approach of considering all ionic species explicitly in the simulations. We find that the DH approach systematically overestimates unbinding rates, relative to the calculations where all ion pairs are present explicitly in solution, although many aspects of the two types of calculation are qualitatively similar. For facilitated dissociation (FD) (acceleration of unbinding by free ligands in solution) explicit-ion simulations lead to unbinding at lower free-ligand concentrations. Our simulations predict a variety of FD regimes as a function of free-ligand and ion concentrations; a particularly interesting regime is at intermediate concentrations of ligands where nonelectrostatic binding strength controls FD. We conclude that explicit-ion electrostatic modeling is an essential component to quantitatively tackle problems in molecular ligand dissociation, including nucleic-acid-binding proteins.

  20. Lebanon and Syria: between dissociation and spillover

    Directory of Open Access Journals (Sweden)

    Javier Lion Bustillo

    2014-12-01

    Full Text Available The risk of Syrian civil war violence spreading towards Lebanon is high. This can be explained by various factors deriving as much from the neighbouring conflict as from other existing factors in Lebanese politics, which have led to the significant collaboration of Lebanon’s Future Movement and Hezbollah with their respective allies in Syria, and to undermining Najib Mikati’s dissociation policies. However, the leaders of those parties tend to balance their will to preserve their confessional leadership with an image of being the defender of national interests. This limits the possibility of an openly sectarian conflict, but it does not totally eliminate it.

  1. 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

  2. Adsorption and dissociation of dinitrogen on transition metal (Ta, W and Re) doped MgO surface

    KAUST Repository

    Yadav, Manoj Kumar

    2016-06-16

    The adsorption and dissociation of dinitrogen on transition metal (Ta, W and Re) doped MgO(100) surface has been studied employing density functional theory. It is found that all these transition metals (TM) on MgO(100) surface are capable of adsorbing dinitrogen (N2), however there is no dissociative adsorption of N2 on single transition metal dopant. When two TM atoms are doped on MgO(100) surface, dissociative adsorption of dinitrogen occurs in all the three cases. Whether the dissociation is spontaneous or is it associated with activation barrier depends on the orientation of N2 molecule approaching the dopant site.

  3. Dissociative detachment relates to psychotic symptoms and personality decompensation.

    Science.gov (United States)

    Allen, J G; Coyne, L; Console, D A

    1997-01-01

    Previous studies have addressed the prominence of psychotic symptoms in conjunction with multiple personality disorder (now dissociative identity disorder). The present study examines the relation between psychotic symptoms and a more pervasive form of dissociative disturbance, namely dissociative detachment. Two hundred sixty-six women in inpatient treatment for severe trauma-related disorders completed the Dissociative Experiences Scale (DES), and 102 of these patients also completed the Millon Clinical Multiaxial Inventory (MCMI-III). A factor analysis of the DES yielded two dimensions of dissociative detachment: detachment from one's own actions and detachment from the self and the environment. Each of these DES dimensions relates strongly to the thought disorder and schizotypal personality disorder scales of the MCMI-III. We propose that severe dissociative detachment, by virtue of loosening the moorings in inner and outer reality, is conducive to psychotic symptoms and personality decompensation.

  4. Dissociation energy of the ground state of NaH

    International Nuclear Information System (INIS)

    Huang, Hsien-Yu; Lu, Tsai-Lien; Whang, Thou-Jen; Chang, Yung-Yung; Tsai, Chin-Chun

    2010-01-01

    The dissociation energy of the ground state of NaH was determined by analyzing the observed near dissociation rovibrational levels. These levels were reached by stimulated emission pumping and fluorescence depletion spectroscopy. A total of 114 rovibrational levels in the ranges 9≤v '' ≤21 and 1≤J '' ≤14 were assigned to the X 1 Σ + state of NaH. The highest vibrational level observed was only about 40 cm -1 from the dissociation limit in the ground state. One quasibound state, above the dissociation limit and confined by the centrifugal barrier, was observed. Determining the vibrational quantum number at dissociation v D from the highest four vibrational levels yielded the dissociation energy D e =15 815±5 cm -1 . Based on new observations and available data, a set of Dunham coefficients and the rotationless Rydberg-Klein-Rees curve were constructed. The effective potential curve and the quasibound states were discussed.

  5. Alkali promotion of N-2 dissociation over Ru(0001)

    DEFF Research Database (Denmark)

    Mortensen, Jens Jørgen; Hammer, Bjørk; Nørskov, Jens Kehlet

    1998-01-01

    Using self-consistent density functional calculations, we show that adsorbed Na and Cs lower the barrier for dissociation of N2 on Ru(0001). Since N2 dissociation is a crucial step in the ammonia synthesis reaction, we explain in this way the experimental observation that alkali metals promote...... the ammonia synthesis reaction over Ru catalysts. We also show that the origin of this effect is predominantly a direct electrostatic attraction between the adsorbed alkali atoms and the dissociating molecule....

  6. 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.

  7. 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.

  8. 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.

  9. 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).

  10. Autocatalytic water dissociation on Cu(110) at near ambient conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mulleregan, Alice; Andersson, Klas; Ketteler, Guido; Bluhm, Hendrik; Yamamoto, Susumu; Ogasawara, Hirohito; Pettersson, Lars G.M.; Salmeron, Miquel; Nilsson, Anders

    2007-05-16

    Autocatalytic dissociation of water on the Cu(110) metal surface is demonstrated based on X-ray photoelectron spectroscopy studies carried out in-situ under near ambient conditions of water vapor pressure (1 Torr) and temperature (275-520 K). The autocatalytic reaction is explained as the result of the strong hydrogen-bond in the H{sub 2}O-OH complex of the dissociated final state, which lowers the water dissociation barrier according to the Broensted-Evans-Polanyi relations. A simple chemical bonding picture is presented which predicts autocatalytic water dissociation to be a general phenomenon on metal surfaces.

  11. CO dissociation on magnetic Fen clusters

    KAUST Repository

    Jedidi, Abdesslem

    2014-01-01

    This work theoretically investigates the CO dissociation on Fen nanoparticles, for n in the range of 1-65, focusing on size dependence in the context of the initial step of the Fischer-Tropsch reaction. CO adsorbs molecularly through its C-end on a triangular facet of the nanoparticle. Dissociation becomes easier when the cluster size increases. Then, the C atom is bonded to a square facet that is generated as a result of the adsorption if it does not yet exist in the bare cluster, while the O atom is adsorbed on a triangular facet. In the most stable situation, the two adsorbed atoms remain close together, both having in common one shared first-neighbor iron atom. There is a partial spin quenching of the neighboring Fe atoms, which become more positively charged than the other Fe atoms. The shared surface iron atom resembles a metal-cation from a complex. Despite the small size of the iron cluster considered, fluctuations due to specific configurations do not influence properties for n > 25 and global trends seem significant.

  12. Bottomonium dissociation in a finite density plasma

    Directory of Open Access Journals (Sweden)

    Nelson R.F. Braga

    2017-10-01

    Full Text Available We present a holographic description of the thermal behavior of bb¯ heavy vector mesons inside a plasma at finite temperature and density. The meson dissociation in the medium is represented by the decrease in the height of the spectral function peaks. In order to find a description for the evolution of the quasi-states with temperature and chemical potential it is crucial to use a model that is consistent with the decay constant behavior. The reason is that the height of a spectral function peak is related to the value of the zero temperature decay constant of the corresponding particle. AdS/QCD holographic models are in general not consistent with the observation that decay constants of heavy vector mesons decrease with radial excitation level. However, it was recently shown that using a soft wall background and calculating the correlation functions at a finite position of anti-de Sitter space, associated with an ultraviolet energy scale, it is possible to describe the observed behavior. Here we extend this proposal to the case of finite temperature T and chemical potential μ. A clear picture of the dissociation of bottomonium states as a function of μ and T emerges from the spectral function. The energy scales where the change in chemical potential leads to changes in the thermal properties of the mesons is consistent with QCD expectations.

  13. Multigenerational Dissociation: A Framework for Building Narrative.

    Science.gov (United States)

    McCollum, Sally E

    2015-01-01

    This paper presents the concept of Multigenerational Dissociation (MGD), a behavior pattern that occurs in families in which violence and abuse are re-enacted from one generation to the next, accompanied by denial that the trauma occurred, or if it did, that it was destructive. While revictimization, reenactment, and the intergenerational transmission of trauma are discussed extensively in the literature, MGD helps to view them within a broad historical framework. This is useful for conceptualizing cases therapeutically, and it can also contribute to research on dissociation and recovered memories of trauma and abuse by demonstrating the value of narrative clinical data. Case material is used to illustrate how MGD occurs in people's lives and affects their memories, demonstrating how it becomes a frame within which to convey the dynamics of how traumatic experiences are remembered. This also demonstrates that when clinicians contribute their own narrative data to research on traumatic memory, the science is more accurate, relevant, and comprehensible to clinical and nonclinical researchers.

  14. Fracture-dissociation of ceramic liner.

    Science.gov (United States)

    Hwang, Sung Kwan; Oh, Jin-Rok; Her, Man Seung; Shim, Young Jun; Cho, Tae Yeun; Kwon, Sung Min

    2008-08-01

    The use of BIOLOX delta ceramic (CeramTec AG, Plochingen, Germany) has been increasing. This ceramic prevents cracking by restraining the phase transformation due to the insertion of nano-sized, yttria-stabilized tetragonal zirconia into the alumina matrix. This restrains the progress of cracking through the formation of platelet-like crystal or whiskers due to the addition of an oxide additive. We observed a case of BIOLOX delta ceramic liner (CeramTec AG) rim fracture 4 months postoperatively. Radiographs showed that the ceramic liner was subluxated from the acetabular cup. Scratches on the acetabular cup and femoral neck were seen, and the fracture was visible on the rim of the liner. Under electron microscope, metal particle coatings from the ceramic liner were identified. The ceramic liner, fracture fragments, and adjacent tissues were removed and replaced with a ceramic liner and femoral head of the same size and design. We believe the mechanism of the fracture-dissociation of the ceramic liner in this case is similar to a case of separation of the ceramic liner from the polyethylene shell in a sandwich-type ceramic-ceramic joint. To prevent ceramic liner fracture-dissociation, the diameter of the femoral neck needs to be decreased in a new design, while the diameter of the femoral head needs to be increased to ensure an increase in range of motion.

  15. Autobiographical memory specificity in dissociative identity disorder.

    Science.gov (United States)

    Huntjens, Rafaële J C; Wessel, Ineke; Hermans, Dirk; van Minnen, Agnes

    2014-05-01

    A lack of adequate access to autobiographical knowledge has been related to psychopathology. More specifically, patients suffering from depression or a history of trauma have been found to be characterized by overgeneral memory, in other words, they show a relative difficulty in retrieving a specific event from memory located in time and place. Previous studies of overgeneral memory have not included patients with dissociative disorders. These patients are interesting to consider, as they are hypothesized to have the ability to selectively compartmentalize information linked to negative emotions. This study examined avoidance and overgeneral memory in patients with dissociative identity disorder (DID; n = 12). The patients completed the autobiographical memory test (AMT). Their performance was compared with control groups of posttraumatic stress disorder (PTSD) patients (n = 26), healthy controls (n = 29), and DID simulators (n = 26). Specifically, we compared the performance of separate identity states in DID hypothesized to diverge in the use of avoidance as a coping strategy to deal with negative affect. No significant differences in memory specificity were found between the separate identities in DID. Irrespective of identity state, DID patients were characterized by a lack of memory specificity, which was similar to the lack of memory specificity found in PTSD patients. The converging results for DID and PTSD patients add empirical evidence for the role of overgeneral memory involved in the maintenance of posttraumatic psychopathology.

  16. Mechanical Dissociation of Retinal Neurons with Vibration

    Science.gov (United States)

    Motomura, Tamami; Hayashida, Yuki; Murayama, Nobuki

    The neuromorphic device, which implements the functions of biological neural circuits by means of VLSI technology, has been collecting much attention in the engineering fields in the last decade. Concurrently, progress in neuroscience research has revealed the nonlinear computation in single neuron levels, suggesting that individual neurons are not merely the circuit elements but computational units. Thus, elucidating the properties of neuronal signal processing is thought to be an essential step for developing the next generation of neuromorphic devices. In the present study, we developed a method for dissociating single neurons from specific sublayers of mammalian retinas with using no proteolytic enzymes but rather combining tissue incubation in a low-Ca2+ medium and the vibro-dissociation technique developed for the slices of brains and spinal cords previously. Our method took shorter time of the procedure, and required less elaborated skill, than the conventional enzymatic method did; nevertheless it yielded enough number of the cells available for acute electrophysiological experiments. The isolated retinal neurons were useful for measuring the nonlinear membrane conductances as well as the spike firing properties under the perforated-patch whole-cell configuration. These neurons also enabled us to examine the effects of proteolytic enzymes on the membrane excitability in those cells.

  17. Products of Dissociative Recombination in the Ionosphere

    Science.gov (United States)

    Cosby, Philip

    1996-01-01

    SRI International undertook a novel experimental measurement of the product states formed by dissociative recombination (DR) of O2(+), NO(+), and N2(+) as a function of both electron energy and reactant ion vibrational level. For these measurements we used a recently developed experimental technique for measuring dissociation product distributions that allows both the branching ratios to be accurately determined and the electronic and rovibrational state composition of the reactant ions to be specified. DR is the dominant electron loss mechanism in all regions of the ionosphere. In this process, electron attachment to the molecular ion produces an unstable neutral molecule that rapidly dissociates. For a molecular ion such as O2(+), the dissociation recombination reaction is (1) O2(+) + e yields O + O + W. The atomic products of this reaction, in this case two oxygen atoms, can be produced in a variety of excited states and with a variety of kinetic energies, as represented by W in Eq. (1). These atoms are not only active in the neutral chemistry of the ionosphere, but are also especially important because their optical emissions are often used to infer in situ concentrations of the parent molecular ion and ambient electron densities. Many laboratory measurements have been made of DR reaction rates under a wide range of electron temperatures, but very little is known about the actual distributions among the final states of the atomic products. This lack of knowledge seriously limits the validity and effectiveness of efforts to model both natural and man-made ionospheric disturbances. Bates recently identified major deficiencies in the currently accepted branching ratios for O2(+) as they relate to blue and green line emission measurements in the nocturnal F-region. During our two-year effort, we partially satisfied our ambitious goals. We constructed and operated a variable pressure, electron-impact ion source and a high pressure, hollow-cathode discharge ion

  18. Controls on Gas Hydrate Formation and Dissociation

    Energy Technology Data Exchange (ETDEWEB)

    Miriam Kastner; Ian MacDonald

    2006-03-03

    The main objectives of the project were to monitor, characterize, and quantify in situ the rates of formation and dissociation of methane hydrates at and near the seafloor in the northern Gulf of Mexico, with a focus on the Bush Hill seafloor hydrate mound; to record the linkages between physical and chemical parameters of the deposits over the course of one year, by emphasizing the response of the hydrate mound to temperature and chemical perturbations; and to document the seafloor and water column environmental impacts of hydrate formation and dissociation. For these, monitoring the dynamics of gas hydrate formation and dissociation was required. The objectives were achieved by an integrated field and laboratory scientific study, particularly by monitoring in situ formation and dissociation of the outcropping gas hydrate mound and of the associated gas-rich sediments. In addition to monitoring with the MOSQUITOs, fluid flow rates and temperature, continuously sampling in situ pore fluids for the chemistry, and imaging the hydrate mound, pore fluids from cores, peepers and gas hydrate samples from the mound were as well sampled and analyzed for chemical and isotopic compositions. In order to determine the impact of gas hydrate dissociation and/or methane venting across the seafloor on the ocean and atmosphere, the overlying seawater was sampled and thoroughly analyzed chemically and for methane C isotope ratios. At Bush hill the pore fluid chemistry varies significantly over short distances as well as within some of the specific sites monitored for 440 days, and gas venting is primarily focused. The pore fluid chemistry in the tub-warm and mussel shell fields clearly documented active gas hydrate and authigenic carbonate formation during the monitoring period. The advecting fluid is depleted in sulfate, Ca Mg, and Sr and is rich in methane; at the main vent sites the fluid is methane supersaturated, thus bubble plumes form. The subsurface hydrology exhibits both

  19. Resonance processes in e - H2 collisions: Dissociative attachment and dissociation from vibrationally and rotationally excited states

    International Nuclear Information System (INIS)

    Fabrikant, I.; Xu, Y.; Wadehra, J.M.

    2002-01-01

    We summarize theoretical studies of dissociative electron attachment to rovibrationally excited H2 molecules by comparing results of earlier local calculations with the results of more recent nonlocal complex potential calculations. The extension of the resonance theory to the near-threshold resonant dissociation is discussed and results are shown for dissociation from vibrationally excited states. Contributions from two negative-ion resonances, 2 Σ + u shape resonance and 2 Σ + g Feshbach resonance, are analysed. We also demonstrate the isotope effect by presenting the peak values of the dissociative attachment cross section for all five isotopic substitutes of H 2

  20. Child Abuse and Revictimization: Depression and Dissociation as Mediator Variables.

    Science.gov (United States)

    Becker-Lausen, Evvie; And Others

    Based on a review of prior research, a causal model was proposed to explain the relationship between child abuse, dissociation, depression, and revictimization. In the model, dissociation and depression were proposed as mediator variables, developing out of child abuse and leading to revictimization. Subjects were 301 male and female university…

  1. Multiple Personality and the Pathological Dissociation of Self.

    Science.gov (United States)

    Price, Reese E.

    This paper considers the condition of Multiple Personality Disorder (MPD), which is defined as a separation of alternating personalities by rigid boundaries and amnestic barriers. It is proposed that MPD represents the end of a continuum of a defensive dissociation of the self that can result when a child employs a dissociative splitting of self…

  2. Errors of Logic and Scholarship Concerning Dissociative Identity Disorder

    Science.gov (United States)

    Ross, Colin A.

    2009-01-01

    The author reviewed a two-part critique of dissociative identity disorder published in the "Canadian Journal of Psychiatry". The two papers contain errors of logic and scholarship. Contrary to the conclusions in the critique, dissociative identity disorder has established diagnostic reliability and concurrent validity, the trauma histories of…

  3. 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…

  4. Dissociative Disorders in Children: Behavioral Profiles and Problems.

    Science.gov (United States)

    Putnam, Frank W.

    1993-01-01

    Clinical research has established a connection between childhood trauma and the development of dissociative disorders in adults. Pathological dissociation produces a range of symptoms and behaviors such as amnesias, rapid shifts in mood and behavior, and auditory and visual hallucinations. Many of these symptoms are misdiagnosed as attention,…

  5. PTSD in relation to dissociation in traumatized police officers

    NARCIS (Netherlands)

    Carlier, I. V.; Lamberts, R. D.; Fouwels, A. J.; Gersons, B. P.

    1996-01-01

    The assumed relationship between dissociation and symptoms of posttraumatic stress disorder (PTSD) was examined. From a group of police officers who had experienced a traumatic event, the authors assessed the chronic dissociative symptoms of 42 police officers with PTSD, 50 police officers with

  6. Quantum chemical study of mechanisms of dissociation and ...

    Indian Academy of Sciences (India)

    Based on potential energy curves for bond dissociation and the transition state and IRC studies, it is found that besides the direct dissociation of carbonyl cyanide, a photoisomerization process through a non-planar transition state may also occur resulting in the formation of a stable and planar isomer CNC(O)CN.

  7. A DFT study of temperature dependent dissociation mechanism of ...

    Indian Academy of Sciences (India)

    of HF in HF(H2O)7 cluster. SWATANTRA K YADAVa, HIRDYESH MISHRAa,∗ and ASHWANI K TIWARIb,∗ ... Dissociation constant, KRP, of HF dissociation and pKa values of HF in cluster at various temperatures have been reported. ... a series of studies on water cluster by means of graph theory and ab initio methods and ...

  8. Structure sensitivity of CO dissociation on Rh surfaces

    DEFF Research Database (Denmark)

    Mavrikakis, Manos; Baumer, M.; Freund, H.J.

    2002-01-01

    Using periodic self-consistent density functional calculations it is shown that the barrier for CO dissociation is similar to120 kJ/mol lower on the stepped Rh(211) surface than on the close-packed Rh(111) surface. The stepped surface binds molecular CO and the dissociation products more strongly...

  9. Dissociation and social cognition in schizophrenia spectrum disorder

    NARCIS (Netherlands)

    Renard, Selwyn B.; Pijnenborg, Marieke; Lysaker, Paul H.

    While there is emerging evidence that dissociation is linked with trauma history and possibly symptoms in schizophrenia, it remains unclear whether dissociation represents a symptom dimensions in its own right in schizophrenia and as such is uniquely related to other features of illness. To explore

  10. 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

  11. The rise and fall of dissociative identity disorder.

    Science.gov (United States)

    Paris, Joel

    2012-12-01

    Dissociative identity disorder (DID), once considered rare, was frequently diagnosed during the 1980s and 1990s, after which interest declined. This is the trajectory of a medical fad. DID was based on poorly conceived theories and used potentially damaging treatment methods. The problem continues, given that the DSM-5 includes DID and accords dissociative disorders a separate chapter in its manual.

  12. 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'

  13. Dissociating apathy and depression in Parkinson disease

    Science.gov (United States)

    Kirsch-Darrow, L.; Fernandez, H.F.; Marsiske, M.; Okun, M.S.; Bowers, D.

    2010-01-01

    Objective To examine the hypothesis that apathy is a core feature of Parkinson disease (PD) and that apathy can be dissociated from depression. Methods Eighty patients with PD and 20 patients with dystonia completed depression and apathy measures including the Marin Apathy Evaluation Scale (AES), Beck Depression Inventory (BDI), and Centers for Epidemiologic Studies–Depression Scale (CES-D). Results There was a significantly higher severity and frequency of apathy in PD (frequency = 51%, 41/80) than in dystonia (frequency = 20%, 4/20). Apathy in the absence of depression was frequent in PD and did not occur in dystonia (PD = 28.8%, dystonia = 0%). Conclusions Patients with Parkinson disease (PD) experienced significantly higher frequency and severity of apathy when compared with patients with dystonia. Apathy may be a “core” feature of PD and occurs in the absence of depression. PMID:16832074

  14. Thermal dissociation and unfolding of insulin

    DEFF Research Database (Denmark)

    Huus, Kasper; Havelund, Svend; Olsen, Helle B

    2005-01-01

    The thermal stability of human insulin was studied by differential scanning microcalorimetry and near-UV circular dichroism as a function of zinc/protein ratio, to elucidate the dissociation and unfolding processes of insulin in different association states. Zinc-free insulin, which is primarily...... dimeric at room temperature, unfolded at approximately 70 degrees C. The two monomeric insulin mutants Asp(B28) and Asp(B9),Glu(B27) unfolded at higher temperatures, but with enthalpies of unfolding that were approximately 30% smaller. Small amounts of zinc caused a biphasic thermal denaturation pattern...... of insulin. The biphasic denaturation is caused by a redistribution of zinc ions during the heating process and results in two distinct transitions with T(m)'s of approximately 70 and approximately 87 degrees C corresponding to monomer/dimer and hexamer, respectively. At high zinc concentrations (>or=5 Zn(2...

  15. Dissociative identity disorder: An empirical overview.

    Science.gov (United States)

    Dorahy, Martin J; Brand, Bethany L; Sar, Vedat; Krüger, Christa; Stavropoulos, Pam; Martínez-Taboas, Alfonso; Lewis-Fernández, Roberto; Middleton, Warwick

    2014-05-01

    Despite its long and auspicious place in the history of psychiatry, dissociative identity disorder (DID) has been associated with controversy. This paper aims to examine the empirical data related to DID and outline the contextual challenges to its scientific investigation. The overview is limited to DID-specific research in which one or more of the following conditions are met: (i) a sample of participants with DID was systematically investigated, (ii) psychometrically-sound measures were utilised, (iii) comparisons were made with other samples, (iv) DID was differentiated from other disorders, including other dissociative disorders, (v) extraneous variables were controlled or (vi) DID diagnosis was confirmed. Following an examination of challenges to research, data are organised around the validity and phenomenology of DID, its aetiology and epidemiology, the neurobiological and cognitive correlates of the disorder, and finally its treatment. DID was found to be a complex yet valid disorder across a range of markers. It can be accurately discriminated from other disorders, especially when structured diagnostic interviews assess identity alterations and amnesia. DID is aetiologically associated with a complex combination of developmental and cultural factors, including severe childhood relational trauma. The prevalence of DID appears highest in emergency psychiatric settings and affects approximately 1% of the general population. Psychobiological studies are beginning to identify clear correlates of DID associated with diverse brain areas and cognitive functions. They are also providing an understanding of the potential metacognitive origins of amnesia. Phase-oriented empirically-guided treatments are emerging for DID. The empirical literature on DID is accumulating, although some areas remain under-investigated. Existing data show DID as a complex, valid and not uncommon disorder, associated with developmental and cultural variables, that is amenable to

  16. Photon diffractive dissociation in deep inelastic scattering

    International Nuclear Information System (INIS)

    Wuesthoff, M.

    1995-09-01

    The cross section of the Photon Diffractive Dissociation in Deep Inelastic Scattering is calculated in the frame work of perturbative QCD. In the triple Regge region the BFKL-approximation is used to evaluate the leading contributions of the corresponding Feynman diagrams with a subsequent resummation in terms of integral equations. These equations are partly solved leading to an effective two to four gluons transition vertex. This exhibits remarkable properties like the total symmetry under the interchange of gluons, the conformal invariance and a simple colour structure. The presence of four interacting gluons in the t-channel does not support the simple triple Pomeron picture with solely a local vertex. A dimensional conservation law is found for zero momentum transfer with the consequence that a direct coupling of the three BFKL-singularities is absent. Another consequence is the dominance of small transverse momenta at the triple Pomeron vertex. Beyond the triple Regge limit a slightly different approach is used in which the diagrams are calculated with leading log(Q 2 ) accuracy. Higher twist contributions are neglected except for the longitudinal part of the cross section which dominates at small invariant masses M in accordance with QCD-predictions and measurements for the exclusive production of vector mesons. For the comparison with the recently measured Photon Diffractive Dissociation-data from H1 and ZEUS a model for the Pomeron is introduced based on the F 2 -data. In the spirit of the k t -factorization theorem this model is inserted in place of the BFKL-Pomeron. Considering the fact that this approach does not contain free parameters the agreement between the theoretical prediction and the data is found to be good. (orig.)

  17. Controllable dissociations of PH3 molecules on Si(001).

    Science.gov (United States)

    Liu, Qin; Lei, Yanhua; Shao, Xiji; Ming, Fangfei; Xu, Hu; Wang, Kedong; Xiao, Xudong

    2016-04-01

    We demonstrate for the first time to our knowledge that controllable dissociation of PH3 adsorption products PHx (x = 2, 1) can be realized by STM (scanning tunneling microscope) manipulation techniques at room temperature. Five dissociative products and their geometric structures are identified via combining STM experiments and first-principle calculations and simulations. In total we realize nine kinds of controllable dissociations by applying a voltage pulse among the PH3-related structures on Si(001). The dissociation rates of the five most common reactions are measured by the I-t spectrum method as a function of voltage. The suddenly increased dissociation rate at 3.3 V indicates a transition from multivibrational excitation to single-step excitation induced by inelastic tunneling electrons. Our studies prove that selectively breaking the chemical bonds of a single molecule on semiconductor surface by STM manipulation technique is feasible.

  18. Self Blocking of CO Dissociation on a Stepped Ruthenium Surface

    DEFF Research Database (Denmark)

    Vendelbo, Søren Bastholm; Johansson, Martin; Mowbray, Duncan

    2010-01-01

    reaction only occurs on the steps. Under ultra high vacuum (UHV) conditions CO dissociates on the step, the oxygen reacts with CO to form CO2 and the residual carbon blocks the step from further CO dissociation. This mechanism competes with the recombination of carbon and oxygen. At high CO pressures, we......The influence of steps on CO reactions has been studied on a Ru(0 1 (1) over bar 5 4) single crystal with a step density of 4%. Based on temperature programmed desorption (TPD) and oxygen titration experiments as well as density functional theory (DFT) calculations, we show that the CO dissociation...... find step blocking no longer dominates the CO dissociation reaction to the same extent and further carbon uptake is observed. This self-poisoning effect is discussed in relation to similar studies of Ni(14 13 13) where such effects were not observed. We find the apparent dissociation energy on the step...

  19. 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.

  20. Electron Transfer Dissociation and Collision-Induced Dissociation of Underivatized Metallated Oligosaccharides

    Science.gov (United States)

    Schaller-Duke, Ranelle M.; Bogala, Mallikharjuna R.; Cassady, Carolyn J.

    2018-02-01

    Electron transfer dissociation (ETD) and collision-induced dissociation (CID) were used to investigate underivatized, metal-cationized oligosaccharides formed via electrospray ionization (ESI). Reducing and non-reducing sugars were studied including the tetrasaccharides maltotetraose, 3α,4β,3α-galactotetraose, stachyose, nystose, and a heptasaccharide, maltoheptaose. Univalent alkali, divalent alkaline earth, divalent and trivalent transition metal ions, and a boron group trivalent metal ion were adducted to the non-permethylated oligosaccharides. ESI generated [M + Met]+, [M + 2Met]2+, [M + Met]2+, [M + Met - H]+, and [M + Met - 2H]+ most intensely along with low intensity nitrate adducts, depending on the metal and sugar ionized. The ability of these metal ions to produce oligosaccharide adduct ions by ESI had the general trend: Ca(II) > Mg(II) > Ni(II) > Co(II) > Zn(II) > Cu(II) > Na(I) > K(I) > Al(III) ≈ Fe(III) ≈ Cr(III). Although trivalent metals were utilized, no triply charged ions were formed. Metal cations allowed for high ESI signal intensity without permethylation. ETD and CID on [M + Met]2+ produced various glycosidic and cross-ring cleavages, with ETD producing more cross-ring and internal ions, which are useful for structural analysis. Product ion intensities varied based on glycosidic-bond linkage and identity of monosaccharide sub-unit, and metal adducts. ETD and CID showed high fragmentation efficiency, often with complete precursor dissociation, depending on the identity of the adducted metal ion. Loss of water was occasionally observed, but elimination of small neutral molecules was not prevalent. For both ETD and CID, [M + Co]2+ produced the most uniform structurally informative dissociation with all oligosaccharides studied. The ETD and CID spectra were complementary. [Figure not available: see fulltext.

  1. 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.

  2. Sleep loss increases dissociation and affects memory for emotional stimuli.

    Science.gov (United States)

    van Heugten-van der Kloet, Dalena; Giesbrecht, Timo; Merckelbach, Harald

    2015-06-01

    Because of their dreamlike character, authors have speculated about the role that the sleep-wake cycle plays in dissociative symptoms. We investigated whether sleep loss fuels dissociative symptoms and undermines cognitive efficiency, particularly memory functioning. Fifty-six healthy undergraduate students were randomly assigned to an experimental group (n = 28) and a control group (n = 28). The experimental group was deprived of sleep for 36 h in a sleep laboratory; the control group had a regular night of sleep. Sleepiness, mood, and dissociative symptoms were assessed 6 times in the experimental group (control group: 4 times). Several cognitive tasks were administered. Sleep deprivation led to an increase in dissociative symptoms, which was mediated by levels of general distress. Feelings of sleepiness preceded an increase of dissociative symptoms and deterioration of mood. Finally, sleep loss also undermined memory of emotional material, especially in highly dissociative individuals. Limitations included moderate reliability of the mood scale, limited generalizability due to student sample, and a relatively short period of intensive sleep deprivation rather than lengthy but intermittent sleep loss, representative of a clinical population. We found that sleep deprivation had significant effects on dissociation, sleepiness, and mood. Specifically, sleepiness and dissociation increased during the night, while mood deteriorated. Our findings stress the importance of sleep deficiencies in the development of dissociative symptoms. They support the view that sleep disruptions fuel distress, but also degrade memory and attentional control. It is against this background that dissociative symptoms may arise. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. 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

  4. Hydrate thermal dissociation behavior and dissociation enthalpies in methane-carbon dioxide swapping process

    DEFF Research Database (Denmark)

    Mu, Liang; von Solms, Nicolas

    2018-01-01

    The swapping of methane with carbon dioxide in hydrate has been proposed as a potential strategy for geologic sequestration of carbon dioxide and production of methane from natural hydrate deposits. However, this strategy requires a better understanding of the thermodynamic characteristics of CH4...... and CO2 hydrate as well as (CH4 + CO2) or (CH4 + CO2 + N2) mixed hydrates (since (CO2 + N2) gas mixture is often used as the swapping gas), along with the thermal physics property changes during gas exchange. In this study, a high pressure micro-differential scanning calorimetry (HP μ-DSC) was performed...... on synthesized gas hydrates to investigate the dissociation behavior of various hydrates. The hydrate dissociation enthalpies were determined by both μ-DSC measurement and Clapeyron equation. For the single guest molecule hydrate system, the average dissociation enthalpies of CH4 hydrate and CO2 hydrate measured...

  5. 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.

  6. 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

  7. Abnormal Hippocampal Morphology in Dissociative Identity Disorder and Post-Traumatic Stress Disorder Correlates with Childhood Trauma and Dissociative Symptoms

    NARCIS (Netherlands)

    Chalavi, Sima; Vissia, Eline M.; Giesen, Mechteld E.; Nijenhuis, Ellert R. S.; Draijer, Nel; Cole, James H.; Dazzan, Paola; Pariante, Carmine M.; Madsen, Sarah K.; Rajagopalan, Priya; Thompson, Paul M.; Toga, Arthur W.; Veltman, Dick J.; Reinders, Antje A. T. S.

    Smaller hippocampal volume has been reported in individuals with post-traumatic stress disorder (PTSD) and dissociative identity disorder (DID), but the regional specificity of hippocampal volume reductions and the association with severity of dissociative symptoms and/or childhood traumatization

  8. Novel fluid shear-based dissociation device for improved single cell dissociation of spheroids and cell aggregates.

    Science.gov (United States)

    Triantafillu, Ursula L; Nix, Jaron N; Kim, Yonghyun

    2018-01-01

    Biological industries commonly rely on bioreactor systems for the large-scale production of cells. Cell aggregation, clumping, and spheroid morphology of certain suspension cells make their large-scale culture challenging. Growing stem cells as spheroids is indispensable to retain their stemness, but large spheroids (>500 µm diameter) suffer from poor oxygen and nutrient diffusion, ultimately resulting in premature cell death in the centers of the spheroids. Despite this, most large-scale bioprocesses do not have an efficient method for dissociating cells into single cells, but rely on costly enzymatic dissociation techniques. Therefore, we tested a proof-of-concept fluid shear-based mechanical dissociator that was designed to dissociate stem cell spheroids and aggregates. Our prototype was able to dissociate cells while retaining high viability and low levels of apoptosis. The dissociator also did not impact long-term cell growth or spheroid formation. Thus, the dissociator introduced here has the potential to replace traditional dissociation methods. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:293-298, 2018. © 2017 American Institute of Chemical Engineers.

  9. 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.

  10. Jactatio corporis nocturna and dissociative disorder: a case report.

    Science.gov (United States)

    Pelin, Zerrin; Karataş, Semra; Kesebir, Sermin

    2012-01-01

    Jactatio corporis nocturna is a type of parasomnia. Rhythmic body movements during sleep are commonly observed in infancy and early childhood, and spontaneous resolution is expected after the age of 4 years. Rarely, the body movements persist until adulthood. Rhythmic body movements characteristically occur during the wake-sleep transition period, rather than during other sleep stages. Some psychiatric diseases can co-occur with sleep-related movement disorders. A relationship between parasomnias and dissociative disorders has been recently reported. Herein we present a 33-year-old male with nocturnal repetitive rolling body movements and daytime fatigue. The patient also had loss of memory of some important events (such as the day his daughter underwent surgery), and reported that he sometimes confused reality with dreams had fantasies during which he experienced his spirit rising above to watch his body and fantasy. Detailed neuropsychological assessment showed that the patient also had a dissociative disorder. Video-polysomnographic recordings showed repetitive, rolling body movements that occurred only during rapid eye movement (REM) sleep.

  11. Dissociations of the night: individual differences in sleep-related experiences and their relation to dissociation and schizotypy.

    Science.gov (United States)

    Watson, D

    2001-11-01

    The author examined the associations among sleep-related experiences (e.g., hypnagogic hallucinations, nightmares, waking dreams, and lucid dreams), dissociation, schizotypy, and the Big Five personality traits in 2 large student samples. Confirmatory factor analyses indicated that (a) dissociation and schizotypy are strongly correlated-yet distinguishable-constructs, and (b) the differentiation between them can be enhanced by eliminating detachment/depersonalization items from the dissociation scales. A general measure of sleep experiences was substantially correlated with both schizotypy and dissociation (especially the latter) and more weakly related to the Big Five. In contrast, an index of lucid dreaming was weakly related to all of these other scales. These results suggest that measures of dissociation, schizotypy, and sleep-related experiences all define a common domain characterized by unusual cognitions and perceptions.

  12. Dissociative disorders in acute psychiatric inpatients in Taiwan.

    Science.gov (United States)

    Chiu, Chui-De; Meg Tseng, Mei-Chih; Chien, Yi-Ling; Liao, Shih-Cheng; Liu, Chih-Min; Yeh, Yei-Yu; Hwu, Hai-Gwo; Ross, Colin A

    2017-04-01

    Dissociative disorders have been documented to be common psychiatric disorders which can be detected reliably with standardized diagnostic instruments in North American and European psychiatric inpatients and outpatients (20.6% and 18.4%, respectively). However, there are concerns about their cross-cultural manifestations as an apparently low prevalence rate has been reported in East Asian inpatients and outpatients (1.7% and 4.9%, respectively). It is unknown whether the clinical profile of dissociative disorders in terms of their core symptomatic clusters, associated comorbid disorders, and environmental risk factors that has emerged in western clinical populations can also be found in non-western clinical populations. A standardized structured interview for DSM-IV dissociative disorders, post-traumatic stress disorder, and a history of interpersonal victimization was administered in a sample of Taiwanese acute psychiatric inpatients. Our results showed that 19.5% of our participants met criteria for a DSM-IV dissociative disorder, mostly dissociative disorder not otherwise specified. More importantly, the western clinical profile of dissociative disorders also characterized our patients, including a poly-symptomatic presentation and a history of interpersonal trauma in both childhood and adulthood. Our results lend support to the conclusion that cross-cultural manifestations of dissociative pathology in East Asia are similar to those in North America and Europe. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  13. Does Nitric Acid Dissociate at the Aqueous Solution Surface?

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Tanza; Winter, Berndt; Stern, Abraham C.; Baer, Marcel D.; Mundy, Christopher J.; Tobias, Douglas J.; Hemminger, J. C.

    2011-11-03

    Nitric acid is a prevalent component of atmospheric aerosols, and the extent of nitric acid dissociation at aqueous interfaces is relevant to its role in heterogeneous atmospheric chemistry. Several experimental and theoretical studies have suggested that the extent of dissociation of nitric acid near aqueous interfaces is less than in bulk solution. Here, dissociation of HNO3 at the surface of aqueous nitric acid is quantified using X-ray photoelectron spectroscopy of the nitrogen local electronic structure. The relative amounts of undissociated HNO3(aq) and dissociated NO3-(aq) are identified by the distinguishable N1s core-level photoelectron spectra of the two species, and we determine the degree of dissociation, αint, in the interface (the first ~3 layers of solution) as a function of HNO3 concentration. Our measurements show that dissociation is decreased by approximately 20% near the solution interface compared with bulk, and furthermore that dissociation occurs even in the top-most solution layer. The experimental results are supported by first-principles MD simulations, which show that hydrogen-bonds between HNO3 and water molecules at the solution surface stabilize the molecular form at low concentration, in analogy to the stabilization of molecular HNO3 that occurs in bulk solution at high concentration. This work was supported by the U.S. Department of Energy's (DOE) Office of Basic Energy Sciences, Chemical Sciences program. The Pacific Northwest National Laboratory is operated by Battelle for DOE.

  14. 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.

  15. Scapulothoracic Dissociation: A Rare Variant: A Case Report

    Directory of Open Access Journals (Sweden)

    Rajat Jangir

    2014-07-01

    Full Text Available Scapulothoracic dissociation is a rare injury involving separation of scapula from the thorax along with the upper extremity. Majority of the patients have concomitant neurovascular injury and the prognosis is uniformly poor in such cases. We present a case of scapulothoracic dissociation with comminuted fracture of scapula and acromioclavicular joint disruption without neurovascular deficit. There were associated avulsion fractures of the spinous processes of vertebrae (T3-T5. Such presentation is rare in an already rare scapulothoracic dissociation injury. A discussion regarding the probable mechanism of injury, management and prognosis is presented.

  16. Electron Capture Dissociation of Weakly Bound Polypeptide Polycationic Complexes

    DEFF Research Database (Denmark)

    Haselmann, Kim F; Jørgensen, Thomas J D; Budnik, Bogdan A

    2002-01-01

    as well as specific complexes of modified glycopeptide antibiotics with their target peptide. The weak nature of bonding is substantiated by blackbody infrared dissociation, low-energy collisional excitation and force-field simulations. The results are consistent with a non-ergodic ECD cleavage mechanism.......We have previously reported that, in electron capture dissociation (ECD), rupture of strong intramolecular bonds in weakly bound supramolecular aggregates can proceed without dissociation of weak intermolecular bonds. This is now illustrated on a series of non-specific peptide-peptide dimers...

  17. State dissociation, human behavior, and consciousness.

    Science.gov (United States)

    Mahowald, Mark W; Cramer Bornemann, Michel A; Schenck, Carlos H

    2011-01-01

    Sleep is clearly not only a whole-brain or global phenomenon, but can also be a local phenomenon. This accounts for the fact that the primary states of being (wakefulness, NREM sleep, and REM sleep) are not necessarily mutually exclusive, and components of these states may appear in various combinations, with fascinating clinical consequences. Examples include: sleep inertia, narcolepsy, sleep paralysis, lucid dreaming, REM sleep behavior disorder, sleepwalking, sleep terrors, out-of-body experiences, and reports of alien abduction. The incomplete declaration of state likewise has implications for consciousness - which also has fluid boundaries. Fluctuations in the degree of consciousness are likely explained by abnormalities of a "spatial and temporal binding rhythm" which normally results in a unified conscious experience. Dysfunctional binding may play a role in anesthetic states, autism, schizophrenia, and neurodegenerative disorders. Further study of the broad spectrum of dissociated states of sleep and wakefulness that are closely linked with states of consciousness and unconsciousness by basic neuroscientists, clinicians, and members of the legal profession will provide scientific, clinical and therapeutic insights, with forensic implications.

  18. Tissue dissociation enzyme neutral protease assessment.

    Science.gov (United States)

    Breite, A G; Dwulet, F E; McCarthy, R C

    2010-01-01

    Neutral proteases, essential components of purified tissue dissociation enzymes required for successful human islet isolation, show variable activities and effects of substrate on their activities. Initially we used a spectrophotometric endpoint assay with azocasein substrate to measure neutral protease activity. After critical review of the results, we observed these data to be inconsistent and not correlating expected differences in specific activities between thermolysin and Bacillus polymyxa proteases. This observation led to the development of a fluorescent microplate assay using fluorescein isothyocyanate-conjugated bovine serum albumin (FITC-BSA) as the substrate. This simpler, more flexible method offered a homogeneous, kinetic enzyme assay allowing determination of steady state reaction rates of sample replicates at various dilutions. The assay had a linear range of 4- to 8-fold and interassay coefficients of variation for B polymyxa protease and thermolysin of inhibitors, as illustrated by addition of sulfhydryl protease inhibitors, which, consistent with earlier reports, strongly indicated that the main contaminant in purified collagenase preparations was clostripain. Determination of the specific activities for several purified neutral proteases showed that the B polymyxa and Clostridium histolyticum proteases had approximately 40% and 15% specific activities, respectively, of those obtained with purified thermolysin, indicating the different characteristics of neutral protease enzymes for cell isolation procedures. Copyright 2010 Elsevier Inc. All rights reserved.

  19. Visuomotor Dissociation in Cerebral Scaling of Size.

    Directory of Open Access Journals (Sweden)

    Adriaan R E Potgieser

    Full Text Available Estimating size and distance is crucial in effective visuomotor control. The concept of an internal coordinate system implies that visual and motor size parameters are scaled onto a common template. To dissociate perceptual and motor components in such scaling, we performed an fMRI experiment in which 16 right-handed subjects copied geometric figures while the result of drawing remained out of sight. Either the size of the example figure varied while maintaining a constant size of drawing (visual incongruity or the size of the examples remained constant while subjects were instructed to make changes in size (motor incongruity. These incongruent were compared to congruent conditions. Statistical Parametric Mapping (SPM8 revealed brain activations related to size incongruity in the dorsolateral prefrontal and inferior parietal cortex, pre-SMA / anterior cingulate and anterior insula, dominant in the right hemisphere. This pattern represented simultaneous use of a 'resized' virtual template and actual picture information requiring spatial working memory, early-stage attention shifting and inhibitory control. Activations were strongest in motor incongruity while right pre-dorsal premotor activation specifically occurred in this condition. Visual incongruity additionally relied on a ventral visual pathway. Left ventral premotor activation occurred in all variably sized drawing while constant visuomotor size, compared to congruent size variation, uniquely activated the lateral occipital cortex additional to superior parietal regions. These results highlight size as a fundamental parameter in both general hand movement and movement guided by objects perceived in the context of surrounding 3D space.

  20. Visuomotor Dissociation in Cerebral Scaling of Size.

    Science.gov (United States)

    Potgieser, Adriaan R E; de Jong, Bauke M

    2016-01-01

    Estimating size and distance is crucial in effective visuomotor control. The concept of an internal coordinate system implies that visual and motor size parameters are scaled onto a common template. To dissociate perceptual and motor components in such scaling, we performed an fMRI experiment in which 16 right-handed subjects copied geometric figures while the result of drawing remained out of sight. Either the size of the example figure varied while maintaining a constant size of drawing (visual incongruity) or the size of the examples remained constant while subjects were instructed to make changes in size (motor incongruity). These incongruent were compared to congruent conditions. Statistical Parametric Mapping (SPM8) revealed brain activations related to size incongruity in the dorsolateral prefrontal and inferior parietal cortex, pre-SMA / anterior cingulate and anterior insula, dominant in the right hemisphere. This pattern represented simultaneous use of a 'resized' virtual template and actual picture information requiring spatial working memory, early-stage attention shifting and inhibitory control. Activations were strongest in motor incongruity while right pre-dorsal premotor activation specifically occurred in this condition. Visual incongruity additionally relied on a ventral visual pathway. Left ventral premotor activation occurred in all variably sized drawing while constant visuomotor size, compared to congruent size variation, uniquely activated the lateral occipital cortex additional to superior parietal regions. These results highlight size as a fundamental parameter in both general hand movement and movement guided by objects perceived in the context of surrounding 3D space.

  1. Dissociable learning processes in comparative psychology.

    Science.gov (United States)

    Smith, J David; Church, Barbara A

    2017-08-10

    Comparative and cognitive psychologists interpret performance in different ways. Animal researchers invoke a dominant construct of associative learning. Human researchers acknowledge humans' capacity for explicit-declarative cognition. This article offers a way to bridge a divide that defeats productive cross-talk. We show that animals often challenge the associative-learning construct, and that it does not work to try to stretch the associative-learning construct to encompass these performances. This approach thins and impoverishes that important construct. We describe an alternative approach that restrains the construct of associative learning by giving it a clear operational definition. We apply this approach in several comparative domains to show that different task variants change-in concert-the level of awareness, the declarative nature of knowledge, the dimensional breadth of knowledge, and the brain systems that organize learning. These changes reveal dissociable learning processes that a unitary associative construct cannot explain but a neural-systems framework can explain. These changes define the limit of associative learning and the threshold of explicit cognition. The neural-systems framework can broaden empirical horizons in comparative psychology. It can offer animal models of explicit cognition to cognitive researchers and neuroscientists. It can offer simple behavioral paradigms for exploring explicit cognition to developmental researchers. It can enliven the synergy between human and animal research, promising a productive future for both.

  2. Dissociative Ionization and Thermal Decomposition of Cyclopentanone.

    Science.gov (United States)

    Pastoors, Johan I M; Bodi, Andras; Hemberger, Patrick; Bouwman, Jordy

    2017-09-21

    Despite the growing use of renewable and sustainable biofuels in transportation, their combustion chemistry is poorly understood, limiting our efforts to reduce harmful emissions. Here we report on the (dissociative) ionization and the thermal decomposition mechanism of cyclopentanone, studied using imaging photoelectron photoion coincidence spectroscopy. The fragmentation of the ions is dominated by loss of CO, C 2 H 4 , and C 2 H 5 , leading to daughter ions at m/z 56 and 55. Exploring the C 5 H 8 O . + potential energy surface reveals hydrogen tunneling to play an important role in low-energy decarbonylation and probably also in the ethene-loss processes, yielding 1-butene and methylketene cations, respectively. At higher energies, pathways without a reverse barrier open up to oxopropenyl and cyclopropanone cations by ethyl-radical loss and a second ethene-loss channel, respectively. A statistical Rice-Ramsperger-Kassel-Marcus model is employed to test the viability of this mechanism. The pyrolysis of cyclopentanone is studied at temperatures ranging from about 800 to 1100 K. Closed-shell pyrolysis products, namely 1,3-butadiene, ketene, propyne, allene, and ethene, are identified based on their photoion mass-selected threshold photoelectron spectrum. Furthermore, reactive radical species such as allyl, propargyl, and methyl are found. A reaction mechanism is derived incorporating both stable and reactive species, which were not predicted in prior computational studies. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  3. Dissociative attachment - A challenge for chemical physics

    International Nuclear Information System (INIS)

    Burrow, P.D.

    1996-01-01

    The dissociative attachment (DA) process, e + AB → A + B - , appears in a surprisingly diverse number of disciplines ranging from physics to biology, with little overlap among the practitioners. Theory lags well behind experiment at present, and treatments from first principles have thus far been limited to diatomic molecules. Even triatomics will offer a considerable challenge to theory, to say nothing of larger molecules of more chemical interest. As motivation, this presentation will describe a few of the applications of DA in fields that are not likely to be familar to AMO scientists. The author continues with a discussion of DA measurements in a series of progressively larger hydrocarbons containing only a single chlorine atom, the goal being to understand the role played by the hydrocarbon framework. In unsaturated hydrocarbons, the DA cross sections are greatly enhanced by the presence of additional temporary anion states due to the normally empty π* orbitals. When the region of unsaturation is remote from the carbon-chlorine bond, DA measurements provide information about intramolecular electron transfer. Finally, recent measurements on molecules containing two chlorine atoms will be discussed

  4. Interidentity memory transfer in dissociative identity disorder.

    Science.gov (United States)

    Kong, Lauren L; Allen, John J B; Glisky, Elizabeth L

    2008-08-01

    Controversy surrounding dissociative identity disorder (DID) has focused on conflicting findings regarding the validity and nature of interidentity amnesia, illustrating the need for objective methods of examining amnesia that can discriminate between explicit and implicit memory transfer. In the present study, the authors used a cross-modal manipulation designed to mitigate implicit memory effects. Explicit memory transfer between identities was examined in 7 DID participants and 34 matched control participants. After words were presented to one identity auditorily, the authors tested another identity for memory of those words in the visual modality using an exclusion paradigm. Despite self-reported interidentity amnesia, memory for experimental stimuli transferred between identities. DID patients showed no superior ability to compartmentalize information, as would be expected with interidentity amnesia. The cross-modal nature of the test makes it unlikely that memory transfer was implicit. These findings demonstrate that subjective reports of interidentity amnesia are not necessarily corroborated by objective tests of explicit memory transfer. Copyright (c) 2008 APA, all rights reserved.

  5. Interidentity amnesia in dissociative identity disorder.

    Science.gov (United States)

    Morton, John

    2017-07-01

    Patients diagnosed with dissociative identity disorder (DID) usually present with alternative personality states (alters) who take separate control of consciousness. Commonly, one alter will claim they have no awareness of events which took place when another alter was in control. However, some kinds of material are transferred across the alter boundary. Huntjens et al. devised an objective method of demonstrating such transfer. In the main study, following Huntjens et al., for three patients, two alters were taught different sets of nouns. The following week, one of the alters was given a recognition memory test including both sets plus distractor words. The patients in the Huntjens experiment responded in the same way to words in both sets. In the present experiemnt, two of the patients tested had pairs of alters where there was no interference from the material which was presented to the other alter. In one of these cases, there was breakthrough with one pairing of alters, a pattern matched in a subsidiary experiment. The population of individuals with DID are not homogeneous with respect to the depth of the blocking of episodic material from one alter to another.

  6. [Introducing treatment for dissociative identity disorder].

    Science.gov (United States)

    Kitamura, Naoto

    2011-01-01

    This paper is a case presentation and study of the introduction of treatment for Dissociative Identity Disorder (DID). Since one manifestation of the pathology of DID is that sufferers avoid relying on others, at the start of treatment we try to stabilise the relationship between clinicians and patients; that is to say, we aim to build a treatment relationship which will be able to gradually overcome the patients' dread of relying on clinicians. In parallel with this we undertake a thorough psychiatric assessment of their condition. This is a standard treatment plan, which follows the general principles of clinical psychiatry. On the other hand, the specialist aspect of DID treatment calls for handling the unique behaviours of a group of mutually opposed alternating personalities appropriately, while always paying consistent attention to the traumatic memories which are connected to the formation and maintenance of the condition. This paper presents the first DID case which the author has taken charge of. There were some difficulties in the early stages of treatment, but after modifying some parts to acknowledge the alternating personalities as independent personalities in face-to-face interviews and psychological education for families, the stabilisation of the treatment structure progressed gradually and the stability of the relationship between clinicians and patients itself has become the focus.

  7. 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.

  8. Dissociation of changes in the permeability of the blood-brain barrier from catecholamine-induced changes in blood pressure of normotensive and spontaneously hypertensive rats

    International Nuclear Information System (INIS)

    Sankar, R.; Domer, F.R.; Taylor, B.

    1982-01-01

    Researchers have studied the effects of the pressor catecholamine, dopamine, and the depressor catecholamine, isoproterenol, on the systemic blood pressure and the permeability of the blood-brain barrier (BBB) to albumin in normotensive (WKY) and spontaneously hypertensive (SHR) rats. The rats were anesthetized with pentobarbital. The permeability of the BBB to protein was measured by the extravasation of radioiodinated serum albumin (RISA). The permeability was decreased by both catecholamines despite the dose-dependent, yet opposite, changes in blood pressure in the WKY rats. The blood pressure response to both of the catecholamines was enhanced in the SHR rats. Isoproterenol caused a decrease in the permeability of the BBB in the SHR but dopamine did not. Results with both WKY and SHR rats are suggestive of an adrenergically-mediated decrease in movement across the BBB of compounds of large molecular weight, regardless of changes in blood pressure

  9. 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.

  10. 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

  11. 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

  12. The relationship between fatalism, dissociation, and trauma symptoms in Latinos.

    Science.gov (United States)

    Greenwell, Ashley N; Cosden, Merith

    2009-01-01

    Numerous studies have documented an overrepresentation of posttraumatic stress disorder in the Latino population. However, the contributing factors to trauma symptomatology among Latinos are not fully understood. The present study examined 112 low-income, Latino outpatients in a mental health clinic to identify culturally relevant variables that predict trauma symptomatology. Fatalism, peritraumatic dissociation, acculturation, and demographic variables were analyzed. Peritraumatic dissociation was found to account for a significant percentage of the variance in trauma symptoms (21%) as measured by the Peritraumatic Dissociative Experiences Questionnaire-Modified and the Trauma Symptom Inventory. Fatalism measured by the Multiphasic Assessment of Cultural Constructs was not found to be significantly associated with symptom severity. Also, acculturation variables did not predict peritraumatic dissociation. Implications of the findings for trauma research and practice are discussed.

  13. Model-independent determination of dissociation energies: method and applications

    International Nuclear Information System (INIS)

    Vogel, Manuel; Hansen, Klavs; Herlert, Alexander; Schweikhard, Lutz

    2003-01-01

    A number of methods are available for the purpose of extracting dissociation energies of polyatomic particles. Many of these techniques relate the rate of disintegration at a known excitation energy to the value of the dissociation energy. However, such a determination is susceptible to systematic uncertainties, mainly due to the unknown thermal properties of the particles and the potential existence of 'dark' channels, such as radiative cooling. These problems can be avoided with a recently developed procedure, which applies energy-dependent reactions of the decay products as an uncalibrated thermometer. Thus, it allows a direct measurement of dissociation energies, without any assumption on properties of the system or on details of the disintegration process. The experiments have been performed in a Penning trap, where both rate constants and branching ratios have been measured. The dissociation energies determined with different versions of the method yield identical values, within a small uncertainty

  14. J/\\psi-dissociation by a color electric flux tube

    OpenAIRE

    Loh, S.; Greiner, C.; Mosel, U.

    1997-01-01

    We adress the question of how a $c-\\bar{c}$-state (a $J/\\psi $) can be dissociated by the strong color electric fields when moving through a color electric flux tube. The color electric flux tube and the dissociation of the heavy quarkonia state are both described within the Friedberg-Lee color dielectric model. We speculate on the importance of such an effect with respect to the observed $J/\\psi $-suppression in ultrarelativistic heavy ion collisions.

  15. Equilibrium dissociation pressures of lithium hydride and lithium deuteride

    International Nuclear Information System (INIS)

    Smith, H.M.; Webb, R.E.

    1977-12-01

    The equilibrium dissociation pressures of plateau composition lithium hydride and lithium deuteride have been measured from 450 to 750 0 C. These data were used to derive the relationship of dissociation pressure with temperature over this range and to calculate several thermodynamic properties of these materials. Thermodynamic properties determined included the enthalpy, entropy, and free energy of formation; the enthalpy and entropy of fusion; and the melting points

  16. A neuroanatomical dissociation for emotion induced by music

    OpenAIRE

    Johnsen, Erica L.; Tranel, Daniel; Lutgendorf, Susan; Adolphs, Ralph

    2009-01-01

    Does feeling an emotion require changes in autonomic responses, as William James proposed? Can feelings and autonomic responses be dissociated? Findings from cognitive neuroscience have identified brain structures that subserve feelings and autonomic response, including those induced by emotional music. In the study reported here, we explored whether feelings and autonomic responses can be dissociated by using music, a stimulus that has a strong capacity to induce emotional experiences. We te...

  17. [Persistent Perpetrator Contact in a Patient with Dissociative Identity Disorder].

    Science.gov (United States)

    Tschöke, Stefan; Eisele, Frank; Steinert, Tilman

    2016-05-01

    The case of a young woman with still ongoing incest and forced prostitution is presented. The criteria for a dissociative identity disorder (DID) were met. Due to persistent contact to the perpetrator she was repeatedly revictimized. Based on the model of trauma-related dissociation we discuss to what extent she was capable of self-determined decision making as well as therapeutic consequences resulting therefrom. © Georg Thieme Verlag KG Stuttgart · New York.

  18. Microscopic evidence for the dissociation of water molecules on cleaved GaN(11[combining macron]00).

    Science.gov (United States)

    Wu, Shih-Yu; Lang, Liang-Wei; Cai, Pei-Yang; Chen, Yun-Wen; Lai, Yu-Ling; Lin, Ming-Wei; Hsu, Yao-Jane; Lee, Wei-I; Kuo, Jer-Lai; Luo, Meng-Fan; Kuo, Chien-Cheng

    2018-01-03

    The dissociation of water molecules absorbed on a cleaved non-polar GaN(11[combining macron]00) surface was studied primarily with synchrotron-based photoemission spectra and density-functional-theory calculations. The adsorbed water molecules are spontaneously dissociated into hydrogen atoms and hydroxyl groups at either 300 or 130 K, which implies a negligible activation energy (macron]00) respectively. These results highlight the promising applications of the non-polar GaN(11[combining macron]00) surface in water dissociation and hydrogen generation.

  19. Radiogenic changes in the behavior and physiology of the spontaneously hypertensive rat: evidence for a dissociation between acute hypotension and incapacitation

    International Nuclear Information System (INIS)

    Mickley, G.A.; Teitelbaum, H.; Parker, G.A.; Vieras, F.; Dennison, B.A.; Bonney, C.H.

    1982-01-01

    Immediately following exposure to a sufficiently large dose of ionizing radiation, rats and several other species experience a transient period of acute hypotension and an accompanying deficit in performance. Although significant correlations have been reported between the drop in blood pressure and the early transient incapacitation (ETI) and a causal relationship has been suggested, the extent to which hypotension precipitates the occurrence of the behavioral deficits remains uncertain. The present experiments investigated both radiogenic blood pressure and performance changes in a strain of rat bred for hypertension (spontaneously hypertensive rat: SHR) in order to determine if high blood pressure might attenuate ETI. Although male SHRs experienced a severe ETI and a drop in blood pressure, much of the data is inconsistent with the hypothesis that hypotension causes performance decrements. In an additional series of studies, blood volume and serum chemistry data were analyzed. Male SHRs were significantly higher than normotensive controls on several blood chemistry determinations. Exposure to ionizing radiation, more often than not, enhanced these differences. These results could not be explained on the basis of radiogenic blood volume fluctuations

  20. Bioaccumulation of dissociating substances; Bioakkumulation dissoziierender Stoffe

    Energy Technology Data Exchange (ETDEWEB)

    Butte, W.; Plegge, V.; Schettgen, C.; Willenborg, R.; Zauke, G.P. [Oldenburg Univ. (Germany). Fachbereich Chemie; Kuhlmann, H. [Oldenburg Univ. (Germany). Fachbereich Chemie]|[Bundesforschungsanstalt fuer Fischerei, Ahrensburg (Germany). Inst. fuer Fischereioekologie

    2000-02-01

    Bioconcentration factors (BCF) are important parameters to assess the environmental fate of chemicals. In this report we describe the determination of BCF for Triclosan, a trichlorophenoxy phenol, for some dissociating herbicides like Dichlorprop, MCPA, Mecoprop, Triclopyr and Picloram as well as for selected pyrethroids like Cyfluthrin, Cypermethrin, Deltamethrin and Permethrin. It was shown that BCF and rate constants for the uptake of Triclosan are decreasing with an increasing pH of the test water. The BCF for the herbicides evaluated are all below 10, confirming data already reported for herbicides of similar structure. Thus, for these compounds there is no tendency to bioaccumulate. Furthermore, there was no correlation between BCF and n-octanol/water partition coefficients or dissociation constants. BCF of pyrethroids were between 860 and 2200. For the analysis of pyrenthroid metabolites a gas chromatographic method using daughter-ion mass spectrometry for detection was established. The detection limit of this method was 1 {mu}g/kg, but metabolites could not be detected in fish during the bioaccumulation experiments. The high toxicity of pyrethroids for fish was approved; LC50-values were between 1 and 5 {mu}g/l. To evaluate physiological effects in fish, produced by pyrethroids, EROD activities in preparations of trout liver were measured. No increase in activity could be detected, but there was a tendency to lower values. We think this to result from the high toxicity of pyrethroids that could have impaired this enzyme system. (orig.) [German] Biokonzentrationsfaktoren (BCF) sind wichtige Parameter, mit Hilfe derer das Umweltverhalten von Chemikalien abgeschaetzt werden kann. Im Rahmen dieses Forschungsvorhabens wurden BCF-Werte fuer Triclosan, ein Trichlorphenoxyphenol, fuer einige dissoziierende Herbizide: Dichlorprop, MCPA, Mecoprop, Triclopyr und Picloram sowie fuer ausgewaehlte Pyrethroide: Cyfluthrin, Cypermethrin, Deltamethrin und Permethrin

  1. Effect of disorder on exciton dissociation in conjugated polymers

    International Nuclear Information System (INIS)

    Feng Yuwen; Zhao Hui; Chen Yuguang; Yan Yonghong

    2017-01-01

    By using a multi-configurational time-dependent Hartree–Fock (MCTDHF) method for the time-dependent Schrödinger equation and a Newtonian equation of motion for lattice, we investigate the disorder effects on the dissociation process of excitons in conjugated polymer chains. The simulations are performed within the framework of an extended version of the Su–Schrieffer–Heeger model modified to include on-site disorder, off-diagonal, electron–electron interaction, and an external electric field. Our results show that Coulomb correlation effects play an important role in determining the exciton dissociation process. The electric field required to dissociate an exciton can practically impossibly occur in a pure polymer chain, especially in the case of triplet exciton. However, when the on-site disorder effects are taken into account, this leads to a reduction in mean dissociation electric fields. As the disorder strength increases, the dissociation field decreases effectively. On the contrary, the effects of off-diagonal disorder are negative in most cases. Moreover, the dependence of exciton dissociation on the conjugated length is also discussed. (paper)

  2. Cumulative trauma, PTSD and dissociation among Ethiopian refugees in Israel.

    Science.gov (United States)

    Finklestein, Michal; Solomon, Zahava

    2009-01-01

    The aim of this study was to examine the exposure of Ethiopian refugees to pre-, peri- and post-migration stressful events and their implications for both posttraumatic stress disorder (PTSD) and dissociation. A random sample (N = 478) of three groups of refugees took part in the research ("Moses" immigrants, 1984, n = 165; "Solomon" immigrants, 1991, n = 169; "Family Reunification" immigrants, 1995, n = 144). Exposure to stressful events and posttraumatic symptoms were assessed via the Harvard Trauma Questionnaire (HTQ). Post-migration difficulties were assessed via the Post Migration Living Difficulties (PMLD) scale. Dissociation was evaluated using the Dissociation Experience Scale (DES). Significant differences were found among the groups in the rates of PTSD (27%, 15%, and 26%, respectively), but no differences were found in dissociation. A significant relationship was found between PTSD symptoms and cumulative trauma among the three groups, but no such relationship was found between dissociation and cumulative trauma. The differences among the groups were discussed in light of the unique characteristics of cumulative trauma, PTSD and dissociation among Ethiopian refugees.

  3. [Identity and dissociation in cyberspace. A case of dissociative identity disorder associated with internet role playing].

    Science.gov (United States)

    Te Wildt, B T; Kowalewski, E; Meibeyer, F; Huber, T

    2006-01-01

    By mediating dissociative experiences, the Internet can challenge the boundaries of people's sense of identity. To illustrate this hypothesis, a case of dissociative identity disorder (DID) is presented. A young unemployed woman created and frequently played several characters in an online game. For more than 2 years she spent up to 12 h a day in the Internet, assuming various personalities, which in return intruded upon her neglected real life. During the course of an inpatient psychotherapeutic treatment, the clinical diagnosis of DID was confirmed by psychometric testing. After 12 weeks of psychotherapy, the patient had managed to identify her fragmented identities as character traits and integrated them into her core personality. She rearranged her real everyday life, found a new job, and reduced her online activities. Even though the patient's psychopathology stems from a disposition in terms of a personality disorder with histrionic and narcissistic features, excessive internet role play obviously functioned as a trigger to develop DIS. Conclusively, cyberspace's anonymous interactivity may offer the possibility to explore one's identity while also putting at risk its coherence.

  4. Subacute transverse myelitis with Lyme profile dissociation

    Directory of Open Access Journals (Sweden)

    Ajjan, Mohammed

    2008-06-01

    Full Text Available Introduction: Transverse myelitis is a very rare neurologic syndrome with an incidence per year of 1-5 per million population. We are presenting an interesting case of subacute transverse myelitis with its MRI (magnetic resonance imaging and CSF (cerebrospinal fluid findings. Case: A 46-year-old African-American woman presented with decreased sensation in the lower extremities which started three weeks ago when she had a 36-hour episode of sore throat. She reported numbness up to the level just below the breasts. Lyme disease antibodies total IgG (immunoglobulin G and IgM (immunoglobulin M in the blood was positive. Antinuclear antibody profile was within normal limits. MRI of the cervical spine showed swelling in the lower cervical cord with contrast enhancement. Cerebrospinal fluid was clear with negative Borrelia Burgdorferi IgG and IgM. Herpes simplex, mycoplasma, coxiella, anaplasma, cryptococcus and hepatitis B were all negative. No oligoclonal bands were detected. Quick improvement ensued after she was given IV Ceftriaxone for 7 days. The patient was discharged on the 8th day in stable condition. She continued on doxycycline for 21 days. Conclusions: Transverse myelitis should be included in the differential diagnosis of any patient presenting with acute or subacute myelopathy in association with localized contrast enhancement in the spinal cord especially if flu-like prodromal symptoms were reported. Lyme disease serology is indicated in patients with neurological symptoms keeping in mind that dissociation in Lyme antibody titers between the blood and the CSF is possible.

  5. Electromagnetic Dissociation and Spacecraft Electronics Damage

    Science.gov (United States)

    Norbury, John W.

    2016-01-01

    When protons or heavy ions from galactic cosmic rays (GCR) or solar particle events (SPE) interact with target nuclei in spacecraft, there can be two different types of interactions. The more familiar strong nuclear interaction often dominates and is responsible for nuclear fragmentation in either the GCR or SPE projectile nucleus or the spacecraft target nucleus. (Of course, the proton does not break up, except possibly to produce pions or other hadrons.) The less familiar, second type of interaction is due to the very strong electromagnetic fields that exist when two charged nuclei pass very close to each other. This process is called electromagnetic dissociation (EMD) and primarily results in the emission of neutrons, protons and light ions (isotopes of hydrogen and helium). The cross section for particle production is approximately defined as the number of particles produced in nucleus-nucleus collisions or other types of reactions. (There are various kinematic and other factors which multiply the particle number to arrive at the cross section.) Strong, nuclear interactions usually dominate the nuclear reactions of most interest that occur between GCR and target nuclei. However, for heavy nuclei (near Fe and beyond) at high energy the EMD cross section can be much larger than the strong nuclear interaction cross section. This paper poses a question: Are there projectile or target nuclei combinations in the interaction of GCR or SPE where the EMD reaction cross section plays a dominant role? If the answer is affirmative, then EMD mechanisms should be an integral part of codes that are used to predict damage to spacecraft electronics. The question can become more fine-tuned and one can ask about total reaction cross sections as compared to double differential cross sections. These issues will be addressed in the present paper.

  6. Dissociable brain biomarkers of fluid intelligence.

    Science.gov (United States)

    Paul, Erick J; Larsen, Ryan J; Nikolaidis, Aki; Ward, Nathan; Hillman, Charles H; Cohen, Neal J; Kramer, Arthur F; Barbey, Aron K

    2016-08-15

    Cognitive neuroscience has long sought to understand the biological foundations of human intelligence. Decades of research have revealed that general intelligence is correlated with two brain-based biomarkers: the concentration of the brain biochemical N-acetyl aspartate (NAA) measured by proton magnetic resonance spectroscopy (MRS) and total brain volume measured using structural MR imaging (MRI). However, the relative contribution of these biomarkers in predicting performance on core facets of human intelligence remains to be well characterized. In the present study, we sought to elucidate the role of NAA and brain volume in predicting fluid intelligence (Gf). Three canonical tests of Gf (BOMAT, Number Series, and Letter Sets) and three working memory tasks (Reading, Rotation, and Symmetry span tasks) were administered to a large sample of healthy adults (n=211). We conducted exploratory factor analysis to investigate the factor structure underlying Gf independent from working memory and observed two Gf components (verbal/spatial and quantitative reasoning) and one working memory component. Our findings revealed a dissociation between two brain biomarkers of Gf (controlling for age and sex): NAA concentration correlated with verbal/spatial reasoning, whereas brain volume correlated with quantitative reasoning and working memory. A follow-up analysis revealed that this pattern of findings is observed for males and females when analyzed separately. Our results provide novel evidence that distinct brain biomarkers are associated with specific facets of human intelligence, demonstrating that NAA and brain volume are independent predictors of verbal/spatial and quantitative facets of Gf. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  7. The Many Faces of Dissociation: Opportunities for Innovative Research in Psychiatry

    Science.gov (United States)

    2014-01-01

    It has been claimed that the progress of psychiatry has lagged behind that of other medical disciplines over the last few decades. This may suggest the need for innovative thinking and research in psychiatry, which should consider neglected areas as topics of interest in light of the potential progress which might be made in this regard. This review is concerned with one such field of psychiatry: dissociation and dissociative disorders. Dissociation is the ultimate form of human response to chronic developmental stress, because patients with dissociative disorders report the highest frequency of childhood abuse and/or neglect among all psychiatric disorders. The cardinal feature of dissociation is a disruption in one or more mental functions. Dissociative amnesia, depersonalization, derealization, identity confusion, and identity alterations are core phenomena of dissociative psychopathology which constitute a single dimension characterized by a spectrum of severity. While dissociative identity disorder (DID) is the most pervasive condition of all dissociative disorders, partial representations of this spectrum may be diagnosed as dissociative amnesia (with or without fugue), depersonalization disorder, and other specified dissociative disorders such as subthreshold DID, dissociative trance disorder, acute dissociative disorders, and identity disturbances due to exposure to oppression. In addition to constituting disorders in their own right, dissociation may accompany almost every psychiatric disorder and operate as a confounding factor in general psychiatry, including neurobiological and psycho-pharmacological research. While an anti- dissociative drug does not yet exist, appropriate psychotherapy leads to considerable improvement for many patients with dissociative disorders. PMID:25598819

  8. [Dissociative disorders: from Janet to DSM-IV].

    Science.gov (United States)

    Nakatani, Y

    2000-01-01

    I reviewed the literature on dissociation and dissociative disorders from Pierre Janet to DSM-IV, and examined the current trends in research. Janet's theory on hysteria is multifaceted, and is based on three psychological models. Based on a hierarchical model, Janet related hysteric symptoms to the activities within the lower strata of mental hierarchy (automatisms psychologiques), which were demonstrably shown in somnambulism. A second model was based on the concept of a psychological system, which was hypothetically composed of ideas, images, feelings, sensations, and movements. According to this model, dissociation of psychological functions was fundamental to the mechanism of hysteria: loss of integration was thought to engender fixed ideas (ideas fixes) and to lead to the development of a system totally isolated from the whole personality system. Janet also attempted to explain various mental disorders using an economic model. He referred to a loss of equilibration between psychological force and psychological tension. Thus, an unexpected emotional experience was conceived to cause a consumption of reserved psychological force, which was in turn followed by exhaustion associated with hysteric symptoms. Whereas most current researchers regard Janet as the first to study psychological trauma as a principal cause of dissociation, I feel it is important to note that he also emphasized the role of stigmata, i.e., permanent traits of hysteric patients, which were represented as a suggestibility and a tendency toward a narrowing of the consciousness field. Discussion about dissociation and its relation to trauma all but disappeared after Janet. However, during the Second World War and post-war period, some psychiatrists began to pay attention to two emerging phenomena: a high incidence of dissociative symptoms such as fugue and amnesia among combatants, and traumatic neurosis frequently observed among ex-inmates of concentration camps. In the 1970s, interest in

  9. Dissociation between spontaneously hypertensive (SHR) andWistar–Kyoto (WKY) rats in baseline performance and methylphenidate response on measures of attention, impulsivity and hyperactivity in a Visual Stimulus Position Discrimination Task

    Energy Technology Data Exchange (ETDEWEB)

    Thanos, P.K.

    2009-10-08

    The spontaneously hypertensive rat (SHR) is a widely accepted rodent model of Attention Deficit/Hyperactivity Disorder (ADHD), and methylphenidate (MP) is a central nervous systemstimulant that has been shown to have a dose-related positive effect on attention task performance in humans with ADHD. The current study was undertaken to compare SHR to its typical control strain, Wistar-Kyoto(WKY) rats, on the performance of a Visual Stimulus Position Discrimination Task (VSPDT) as well as of the responsiveness of the two rat strains to MP treatment. The rats were initially trained on the VSPDT, in which a light cue was presented randomly at three different cue-light intervals (1 s, 300 ms and 100 ms) over one of two levers, and presses on the lever corresponding to the light cue were reinforced with a food pellet. Once rats reached stable performance, the treatment phase of the study began, during which they received daily intraperitoneal (IP) injections of saline, 2 mg/kg, 5 mg/kg, and 10 mg/kg of MP in a randomized order immediately prior to being tested on the VSPDT. Baseline performance accuracy on the VSPDT did not differ between the groups. Furthermore, a striking strain dissociation was evident in the response of the two strains to treatment; VSPDT performance was substantially disrupted by the 5 and 10 mg/kg dose in the WKY rats but only mildly in the SHR rats. Response omissions were also increased only in WKY rats. Finally, both strains had increased locomotor activity in the operant chamber following MP treatment. These findings point to an important difference in response tendency toMP in the two strains that supports a view that a critical difference between these strains may suggest neurochemical and neuroadaptive differences associated with the behavioral impairments of ADHD.

  10. The adsorption and dissociation of water molecule on goethite (010) surface: A DFT approach

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Long, E-mail: shuweixia@ouc.edu.cn [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, College of Chemistry and Chemical Engineering (China); Xiu, Fangyuan [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, College of Chemistry and Chemical Engineering (China); Qiu, Meng [Qingdao Institute of Bioenergy and Bioprocess Technology (China); Xia, Shuwei; Yu, Liangmin [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, College of Chemistry and Chemical Engineering (China)

    2017-01-15

    Graphical abstract: The optimized structure of hydrated goethite (010) surface with medium water coverage (water density about 6.7 H{sub 2}O/nm{sup 2}). - Highlights: • Stable adsorption and dissociation structure of H{sub 2}O on goethite (010) surface was investigated by DFT. • Reasonable path for water dissociation was proposed by transitional state analysis. • The mechanism of water adsorption on goethite and binding nature were revealed by PDOS. - Abstract: Using density functional theory (DFT) calculation, we investigate the configuration, stability and electronic properties of fresh cleaved (010) goethite surface (Pnma) and this surface exposed to water monolayer at low, medium and high coverage. Water is predicted to be chemisorbed to the surface, together with the surface reconstruction. The interaction energy of the most stable configuration of both low and medium coverage per water molecule is almost the same (−1.17 eV), while that of high coverage is much lower (less than 1.03 eV). It indicates that highly hydrated surface is less stable. PDOS analysis reveals the adsorption of H{sub 2}O is due to the formation of Fe−O bond, caused by overlapping of Fe's 3d and O's 2p orbitals. Dissociation processes at low and medium water coverage are non-spontaneous; while at high coverage, it can undertake spontaneously both thermodynamically and dynamically. The dissociation paths of all three water coverage are the similar. The proton from one adsorbed water is likely to dissociate to bind to the vicinal surface μ{sub 3}−O as an intermediate product; the proton belonged to μ{sub 3}−O transferred to the neighbor surface μ{sub 2}−O as the dissociative configuration.

  11. The Dissociative Electroionization of Carbon Dioxide by low-energy Electron Impact. The C+, O+ and CO+ Dissociation channels.

    OpenAIRE

    Locht, Robert; Davister, M.

    1995-01-01

    This work reports the dissociative ionization of CO2 between 19-40 eV. The three dissociation channels producing C+, O+ and CO+ are examined in detail. Translational energy distributions as a function of the impinging electron energy and the ionization efficiency for fixed kinetic energy carried away by the fragments are measured. The kinetic energy versus appearance energy diagram is obtained for the three fragment ions. When available, the present results are compared with previous measurem...

  12. 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

  13. Is dissociative amnesia a culture-bound syndrome? Findings from a survey of historical literature.

    Science.gov (United States)

    Pope, Harrison G; Poliakoff, Michael B; Parker, Michael P; Boynes, Matthew; Hudson, James I

    2007-02-01

    Natural human psychological phenomena, such as depression, anxiety, delusions, hallucinations and dementia, are documented across the ages in both fictional and non-fictional works. We asked whether 'dissociative amnesia' was similarly documented throughout history. We advertised in three languages on more than 30 Internet web sites and discussion groups, and also in print, offering US$1000 to the first individual who could find a case of dissociative amnesia for a traumatic event in any fictional or non-fictional work before 1800. Our search generated more than 100 replies; it produced numerous examples of ordinary forgetfulness, infantile amnesia and biological amnesia throughout works in English, other European languages, Latin, Greek, Arabic, Sanskrit and Chinese before 1800, but no descriptions of individuals showing dissociative amnesia for a traumatic event. If dissociative amnesia for traumatic events were a natural psychological phenomenon, an innate capacity of the brain, then throughout the millennia before 1800, individuals would presumably have witnessed such cases and portrayed them in non-fictional works or in fictional characters. The absence of cases before 1800 cannot reasonably be explained by arguing that our ancestors understood or described psychological phenomena so differently as to make them unrecognizable to modern readers because spontaneous complete amnesia for a major traumatic event, in an otherwise lucid individual, is so graphic that it would be recognizable even through a dense veil of cultural interpretation. Therefore, it appears that dissociative amnesia is not a natural neuropsychological phenomenon, but instead a culture-bound syndrome, dating from the nineteenth century.

  14. Brucella dissociation is essential for macrophage egress and bacterial dissemination.

    Science.gov (United States)

    Pei, Jianwu; Kahl-McDonagh, Melissa; Ficht, Thomas A

    2014-01-01

    It has long been observed that smooth Brucella can dissociate into rough mutants that are cytotoxic to macrophages. However, the in vivo biological significance and/or mechanistic details of Brucella dissociation and cytotoxicity remain incomplete. In the current report, a plaque assay was developed using Brucella strains exhibiting varying degrees of cytotoxicity. Infected monolayers were observed daily using phase contrast microscopy for plaque formation while Brucella uptake and replication were monitored using an immunofluorescence assay (IFA). Visible plaques were detected at 4-5 days post infection (p.i.) with cytotoxic Brucella 16MΔmanBA at an MOI of 0.1. IFA staining demonstrated that the plaques consisted of macrophages with replicating Brucella. Visible plaques were not detected in monolayers infected with non-cytotoxic 16MΔmanBAΔvirB2 at an MOI of 0.1. However, IFA staining did reveal small groups of macrophages (foci) with replicating Brucella in the monolayers infected with 16MΔmanBAΔvirB2. The size of the foci observed in macrophage monolayers infected with rough Brucella correlated directly with cytotoxicity measured in liquid culture, suggesting that cytotoxicity was essential for Brucella egress and dissemination. In monolayers infected with 16M, small and large foci were observed. Double antibody staining revealed spontaneous rough mutants within the large, but not the small foci in 16M infected monolayers. Furthermore, plaque formation was observed in the large foci derived from 16M infections. Finally, the addition of gentamicin to the culture medium inhibited plaque formation, suggesting that cell-to-cell spread occurred only following release of the organisms from the cells. Taken together, these results demonstrate that Brucella-induced cytotoxicity is critical for Brucella egress and dissemination.

  15. Brucella Dissociation Is Essential for Macrophage Egress and Bacterial Dissemination

    Directory of Open Access Journals (Sweden)

    Thomas A Ficht

    2014-03-01

    Full Text Available It has long been observed that smooth Brucella can dissociate into rough mutants that are cytotoxic to macrophages. However, the in vivo biological significance and/or mechanistic de-tails of Brucella dissociation and cytotoxicity remain incomplete. In the current report, a plaque assay was developed using Brucella strains exhibiting varying degrees of cytotoxicity. Infected monolayers were observed daily using phase contrast microscopy for plaque formation while Brucella uptake and replication were monitored using an immunofluorescence assay (IFA. Vis-ible plaques were detected at 4-5 days post infection (p.i. with cytotoxic Brucella 16M∆manBA at an MOI of 0.1. IFA staining demonstrated that the plaques consisted of macrophages with replicating Brucella. Visible plaques were not detected in monolayers infected with non-cytotoxic 16M∆manBA∆virB2 at an MOI of 0.1. However, IFA staining did reveal small groups of macrophages (foci with replicating Brucella in the monolayers infected with 16M∆manBA∆virB2. The size of the foci observed in macrophage monolayers infected with rough Brucella correlated directly with cytotoxicity measured in liquid culture, suggesting that cytotoxicity was essential for Brucella egress and dissemination. In monolayers infected with 16M, small and large foci were observed. Double antibody staining revealed spontaneous rough mutants within the large, but not the small foci in 16M infected monolayers. Furthermore, plaque formation was observed in the large foci derived from 16M infections. Finally, the addi-tion of gentamicin to the culture medium inhibited plaque formation, suggesting that the cell-to-cell spreading occurred only following release of the organisms from the cells. Taken together, these results demonstrate that Brucella induced cytotoxicity is critical for Brucella egress and dissemination.

  16. 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.

  17. Dissociative symptoms in individuals with gender dysphoria:is the elevated prevalence real?

    OpenAIRE

    Colizzi, Marco; Costa, Rosalia; Todarello, Orlando

    2015-01-01

    This study evaluated dissociative symptomatology, childhood trauma and body uneasiness in 118 individuals with gender dysphoria, also evaluating dissociative symptoms in follow-up assessments after sex reassignment procedures were performed. We used both clinical interviews (Dissociative Disorders Interview Schedule) and self-reported scales (Dissociative Experiences Scale). A dissociative disorder of any kind seemed to be greatly prevalent (29.6%). Moreover, individuals with gender dysphoria...

  18. 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.

  19. Equations for calculating the properties of dissociated steam

    Science.gov (United States)

    Aminov, R. Z.; Gudym, A. A.

    2017-08-01

    The equations of state for dissociated steam have been developed in the temperature and pressure ranges of 1250-2300 K and 0.01-10.00 MPa for calculating thermodynamic processes in thermal power units operating on high-temperature steam. These equations are based on the property tables for dissociated steam derived at a reference temperature of 0 K. It is assumed that the initial substance is steam, the dissociation of which—in accordance with the most likely chemical reactions—results in formation of molecules of hydrogen, oxygen, steam, hydroxyl, and atoms of oxygen and hydrogen. Differential thermodynamic correlations, considering a change in the chemical potential and the composition of the mixture, during the steam dissociation are used. A reference temperature of 0.01°C used in the calculation of parameters of nondissociated steam has been adopted to predict processes in thermal power units without matching the reference temperatures and to account for transformation of dissociated steam into its usual form for which there is the international system of equations with the water triple point of 0.01°C taken as the reference. In the investigated region, the deviation of dissociated steam properties from those of nondissociated steam, which increases with decreasing the pressure or increasing the temperature, was determined. For a pressure of 0.02 MPa and a temperature of 2200 K, these deviations are 512 kJ/kg for the enthalpy, 0.2574 kJ/(kg K) for the entropy, and 3.431 kJ/(kg K) for the heat capacity at constant pressure. The maximum deviation of the dissociated steam properties calculated by the developed equations from the handbook values that these equations are based on does not exceed 0.03-0.05%.

  20. 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.

  1. Photophysical properties of neutral and dissociated forms of rosmarinic acid

    Energy Technology Data Exchange (ETDEWEB)

    Danaf, Nader Al [Department of Chemistry, American University of Beirut, Beirut (Lebanon); Department of Life Sciences and Chemistry, Jacobs University Bremen, Bremen (Germany); Melhem, Racha Abi [Department of Chemistry, American University of Beirut, Beirut (Lebanon); Assaf, Khaleel I.; Nau, Werner M. [Department of Life Sciences and Chemistry, Jacobs University Bremen, Bremen (Germany); Patra, Digambara, E-mail: dp03@aub.edu.lb [Department of Chemistry, American University of Beirut, Beirut (Lebanon)

    2016-07-15

    Polyphenols are bioactive components that have attracted attention by chemists over many years. Rosmarinic acid (RA) is a polyphenol that is widely investigated for its broad range of potential applications as an anti-carcinogenic agent, an anti-inflammatory drug, and antioxidant. The spectroscopic properties of this molecule are addressed in details in this study. The absorption and fluorescence of RA are investigated at different pH values, characterizing the dissociated forms of RA. In a similar manner, RA was characterized in a set of different solvents. The spectral shifts of RA in the different solvents were addressed by using the Lippert–Mataga and the Stokes' shift vs. E{sub T}30 plots, which revealed two sets of linearity for the behavior of RA in polar protic and aprotic solvents. The lifetime decay profile of the dissociated forms of RA and those of RA in different solvents are characterized by bi-exponential lifetime decay functions. A theoretical study on the molecular structure of the different dissociated forms of RA is also reported. The simulated UV–vis spectra of the dissociated forms of RA were studied and compared to the experimental spectra by performing TDDFT calculations. Besides the UV-simulated spectra, the frontier molecular orbitals (FMO) of the different RA dissociated forms were also calculated.

  2. Hippocampal and Amygdalar Volumes in Dissociative Identity Disorder

    Science.gov (United States)

    Vermetten, Eric; Schmahl, Christian; Lindner, Sanneke; Loewenstein, Richard J.; Bremner, J. Douglas

    2011-01-01

    Objective Smaller hippocampal volume has been reported in several stress-related psychiatric disorders, including posttraumatic stress disorder (PTSD), borderline personality disorder with early abuse, and depression with early abuse. Patients with borderline personality disorder and early abuse have also been found to have smaller amygdalar volume. The authors examined hippocampal and amygdalar volumes in patients with dissociative identity disorder, a disorder that has been associated with a history of severe childhood trauma. Method The authors used magnetic resonance imaging to measure the volumes of the hippocampus and amygdala in 15 female patients with dissociative identity disorder and 23 female subjects without dissociative identity disorder or any other psychiatric disorder. The volumetric measurements for the two groups were compared. Results Hippocampal volume was 19.2% smaller and amygdalar volume was 31.6% smaller in the patients with dissociative identity disorder, compared to the healthy subjects. The ratio of hippocampal volume to amygdalar volume was significantly different between groups. Conclusions The findings are consistent with the presence of smaller hippocampal and amygdalar volumes in patients with dissociative identity disorder, compared with healthy subjects. PMID:16585437

  3. Illusory touch and tactile perception in somatoform dissociators.

    Science.gov (United States)

    Brown, Richard J; Brunt, Natalie; Poliakoff, Ellen; Lloyd, Donna M

    2010-09-01

    The psychological mechanisms of somatoform dissociation (i.e., pseudoneurological symptoms) are poorly understood. This study evaluated recent theoretical predictions regarding the role of tactile perception in the development of somatoform dissociative symptoms. Eighty nonclinical participants scoring either high or low on the Somatoform Dissociation Questionnaire (SDQ-20) completed the Somatic Signal Detection Task (SSDT), a novel perceptual paradigm designed to simulate the occurrence of somatoform symptoms in the laboratory. Prior to the SSDT, participants completed a memory task designed to produce either minimal or maximal activation of tactile representations in memory. The high SDQ-20 group exhibited a more liberal response criterion (c) on the SSDT than the low SDQ-20 group after controlling for negative affectivity, somatosensory amplification and depression. This effect was mainly attributable to an increased number of false alarms (i.e., illusory experiences of touch) in the high SDQ-20 group rather than an increased hit rate. General perceptual ability (i.e., tactile sensitivity) was comparable between the two groups. The memory manipulation had no effect on SSDT performance. Somatoform dissociators appear more likely to experience illusory perceptual events under conditions of sensory ambiguity than nondissociators, despite comparable perceptual abilities more generally. These findings support theories that identify distorted perceptual processing as a feature of somatoform dissociation. The SSDT has potential as a tool for further research in this area. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  4. Strategic use of dissociation in ethical argumentation on abortion

    Directory of Open Access Journals (Sweden)

    Simona Mazilu

    2008-01-01

    Full Text Available This paper is concerned with the dialectical and rhetorical consequences of the use of dissociation in ethical argumentation on abortion. Disputants make strategic use of dissociation to advance their standpoints, to establish the starting points of the discussion and to argue in favor or against abortion as well. From the pragma-dialectical perspective (van Rees 2002, 2003, 2005a, 2005b, 2006, dissociation is defined as an argumentative technique by which a unitary concept is divided into two different concepts of which one is intended as positive while the other one as negative. The analysis of a religious text on abortion shows that by means of dissociation abortion can be conceived of as “an unspeakable crime” or “the deliberate killing of an innocent human being” as opposed to “interruption of pregnancy”, the term preferred by pro-choice supporters. I claim that the protagonist uses dissociation as a rhetorical strategy aimed at persuading both the interlocutor and the audience.

  5. Dynamics of dissociation versus ionization in strong laser fields

    International Nuclear Information System (INIS)

    In this paper, experimental results are presented which clearly demonstrate the effectiveness that an external field has in altering the dissociation dynamics. The experiment examines the strong-field dissociation dynamics of molecular hydrogen ions and its deuterated isotopes. These studies involve multiphoton excitation in the intensity regime of 10 11-14 W/cm 2 with the fundamental and second harmonic of a ND:YAG or ND:YLF laser system. Measurements include energy resolved electron and mass spectroscopy which provide useful probes in elucidating the interaction dynamics predicted by existing models. The example this in this paper, examines the strong-field dissociation of H 2 + , HD + , and D 2 + at green (0.5 μm) and (1μm) frequencies. The diatomic ions are formed via multiphonon ionization of the neutral precursor which is physically separable from the dissociation process. This study provides the first observation of the dynamics associated with the above threshold dissociation (ATD) process and analogies will be made with the more familiar above threshold ionization (ATI) phenomenon

  6. Heterolytic dissociative adsorption state of dihydrogen favored by interfacial defects

    Science.gov (United States)

    Song, Zhenjun; Hu, Hanshi; Xu, Hu; Li, Yong; Cheng, Peng; Zhao, Bin

    2018-03-01

    The atomic-scale insight into dihydrogen on MgO(001) surface deposited on molybdenum substrate with interfacial defects was investigated in detail by employing density functional methods Here we report novel dissociative adsorption behaviors of single hydrogen molecule on the usually inert oxide surfaces, with consideration of two types of dissociation schemes. The heterolytic dissociation state -Mg(H)-O(H)- of dihydrogen is impossible to obtain on neighboring O-Mg sites of perfect bulk MgO(001) terraces. Unusually, the hydrogen molecule can form heterolytic fragmentation states on metal supported MgO(001) films with very low activation barrier (0.398 eV), and the heterolytic dissociation state is much more favorable than homolytic dissociation state both energetically and kinetically in all cases. Electronic properties and bonding attribution of adsorbates and the oxide-metal hybrid structure are revealed by analyzing density of states, differential charge densities, orbital interaction and electron localization function. The characteristic changes to the property and activity of magnesia (001) can have potential application in catalytic reactions.

  7. Electron-Impact Dissociation of Hydrocarbon Molecular Ions

    International Nuclear Information System (INIS)

    Bannister, M.E.; Schultz, D.R.

    2014-01-01

    Absolute cross-sections for electron-impact dissociation of CH x + (x = 1, 2, 3) producing CH y + (y = 0, 1, 2) fragment ions were measured in the 3-100 eV range using a crossed electron-ion beams technique with total uncertainties of about 11% near the cross-section peaks. For CH + dissociation, although the measured energy dependence agrees well with two sets of storage ring measurements, the magnitude of the present results lies about 15%-25% lower at the cross-section peak near 40 eV. For dissociation of CH 2 + , the cross-sections are nearly identical for energies above 15 eV, but they are dramatically different at lower energies. The CH + channel exhibits a strong peak rising from an observed threshold of about 6 eV; the C + channel is relatively flat down to the lowest measured energy. For dissociation of CH 3 + and CD 3 + , good agreement is found with other results reported for the CH + fragment, but some differences are found for the CD 2 + and C + fragments. A pilot study has also been undertaken to assess the feasibility of applying a molecular dynamics approach to treat the full range of electron-hydrocarbon dissociation processes, especially for energies above a few eV, in order to provide an overarching theoretical model that can be readily applied. Comparison with the experimental data for CH + shows favourable agreement. (author)

  8. Hippocampal and amygdalar volumes in dissociative identity disorder.

    Science.gov (United States)

    Vermetten, Eric; Schmahl, Christian; Lindner, Sanneke; Loewenstein, Richard J; Bremner, J Douglas

    2006-04-01

    Smaller hippocampal volume has been reported in several stress-related psychiatric disorders, including posttraumatic stress disorder (PTSD), borderline personality disorder with early abuse, and depression with early abuse. Patients with borderline personality disorder and early abuse have also been found to have smaller amygdalar volume. The authors examined hippocampal and amygdalar volumes in patients with dissociative identity disorder, a disorder that has been associated with a history of severe childhood trauma. The authors used magnetic resonance imaging to measure the volumes of the hippocampus and amygdala in 15 female patients with dissociative identity disorder and 23 female subjects without dissociative identity disorder or any other psychiatric disorder. The volumetric measurements for the two groups were compared. Hippocampal volume was 19.2% smaller and amygdalar volume was 31.6% smaller in the patients with dissociative identity disorder, compared to the healthy subjects. The ratio of hippocampal volume to amygdalar volume was significantly different between groups. The findings are consistent with the presence of smaller hippocampal and amygdalar volumes in patients with dissociative identity disorder, compared with healthy subjects.

  9. THERMODYNAMICS OF ETHANOLAMMONIUM CATIONES DISSOCIATION IN AQUEOUS SOLUTIONS

    Directory of Open Access Journals (Sweden)

    R. E. Khoma

    2017-03-01

    Full Text Available The literature data on the thermodynamics of ethanolamines onium cations dissociation have been systematized and generalized. The correlation between these cations dissociation thermodynamic functions (DH and DS and physicochemical properties (Tmp., Tbp, Pp, lgPow et al. has been revealed. There was a correlation between lipophilicity determined experimentally and calculated by QSAR. For monoethanolammonium, diethanolammonium, and their N-methyl and N-ethyl derivatives it was found dissociation thermodynamic functions to depend on bases lgPow. Acid-base dissociation of TRIS and triethanolamine onium cations does not correspond to said relationship because TRIS (primary amine, TEA (tertiary amine act differently on aqueous solutions of SO2. TEA, unlike MEA, DEA and MMEA, has a salting out effect towards sulfur dioxide because of competing hydration that promotes sulfite «onium» salts hydrolysis. TRIS promotes S(IV → S(VI sulphooxidation, in contrast to another ethanolamines. Enthalpy–enthropy compensation with isothermodynamic temperature 303 K has been recorded. The revealed correlations may be useful in developing of procedures for air sanitary cleaning from acidic gases; chemisorbents immobilized for gas and ion exchange chromatography; potentiometric methods for fluorocomplex acids determinations. The use of monoethanolamine is most promising to obtain chemisorbents because the thermodynamic functions of its onium cation acid-base dissociation are least dependent on temperature compared to other etanolammonium cations.

  10. 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.

  11. 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.

  12. 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

  13. Hopping approach towards exciton dissociation in conjugated polymers

    International Nuclear Information System (INIS)

    Emelianova, E. V.; Auweraer, M. van der; Baessler, H.

    2008-01-01

    By employing random walk an analytic theory for the dissociation of singlet excitons in a random organic solid, for instance, a conjugated polymer, has been developed. At variance of conventional three-dimensional Onsager theory, it is assumed that an exciton with finite lifetime can first transfer endothermically an electron to an adjacent site, thereby generating a charge transfer state whose energy is above the energy of that of the initial exciton. In a second step the latter can fully dissociate in accordance with Onsager's concept Brownian motion. The results indicate that, depending of the energy required for the first jump, the first jump contributes significantly to the field dependence of the dissociation yield. Disorder weakens the temperature dependence of the yield dramatically and precludes extracting information on the exciton binding energy from it

  14. Dissociative recombination and electron attachment in regions of star formation

    International Nuclear Information System (INIS)

    Herbst, Eric; Roueff, Evelyne

    2011-01-01

    Dissociative recombination and electron attachment are important in interstellar chemistry, which is heavily dominated by ions and ionic processes. Here we consider how the competition between dissociative recombination and other reactions, such as H-atom transfer, can explain the unusually high observed abundances of the reactive cations OH + and H 2 O + in the dense outflow source in front of the Orion Nebula. We also show how dissociative recombination and other processes might block the achievement of an equilibrium ortho-to-para abundance ratio for H 2 O + in diffuse interstellar clouds. Finally, we consider the formation and destruction rates of molecular anions observed in the interstellar and circumstellar media, especially the formation mechanism of radiative attachment, the rate of which has only been estimated by a simple phase space theory, which is surprisingly successful in most instances.

  15. Electron-impact dissociation of molecular hydrogen into neutral fragments

    Science.gov (United States)

    Scarlett, Liam H.; Tapley, Jonathan K.; Fursa, Dmitry V.; Zammit, Mark C.; Savage, Jeremy S.; Bray, Igor

    2018-02-01

    We present convergent close-coupling calculations of electron-impact dissociation of the ground state of molecular hydrogen into neutral fragments over the range of impact energies from 6 to 300 eV. The calculations account for dissociative excitation, excitation radiative decay dissociation, and predissociation through all bound electronic triplet states, and singlet states up to the D' 1 Π u state. An estimate is given for the contribution from the remaining bound electronic singlet states. Our results are in agreement with the recommended data of Yoon et al. [J. Phys. Chem. Ref. Data 37, 913 (2008)] in the low (6-12 eV) and high (60-70 eV) energy regions, but somewhat lower at the intermediate energies.

  16. The Dynamics of Dissociative Electron Attachment to Small Polyatomic Molecules

    Science.gov (United States)

    Rescigno, Thomas

    2013-09-01

    Dissociative electron attachment (DEA) is a resonant process in which an electron attaches to a molecule to form an unstable anion which subsequently fragments into stable products. DEA to small polyatomic molecules is often governed by complex electronic and nuclear dynamics that is intrinsically multi-dimensional. One-dimensional treatments of the dissociation dynamics based on resonance scattering theory, while often successful in modeling the energy dependence of total cross sections, can mask the complexity of post-attachment dynamics which is revealed by the observed angular dependence of the reaction products. The dissociation evolves on transient anion potential energy surfaces and often involves conical intersections which can result in a complete breakdown of the axial recoil approximation. I will use the examples of DEA to water, carbon dioxide and methanol to illustrate the discussion. Work performed under auspices of USDOE by LBNL under contract DE-AC02-05CH11231 and supported by OBES, Division of Chemical Sciences.

  17. 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.

  18. Reaction paths of phosphine dissociation on silicon (001)

    International Nuclear Information System (INIS)

    Warschkow, O.; McKenzie, D. R.; Curson, N. J.; Schofield, S. R.; Marks, N. A.; Wilson, H. F.; Radny, M. W.; Smith, P. V.; Reusch, T. C. G.; Simmons, M. Y.

    2016-01-01

    Using density functional theory and guided by extensive scanning tunneling microscopy (STM) image data, we formulate a detailed mechanism for the dissociation of phosphine (PH 3 ) molecules on the Si(001) surface at room temperature. We distinguish between a main sequence of dissociation that involves PH 2 +H, PH+2H, and P+3H as observable intermediates, and a secondary sequence that gives rise to PH+H, P+2H, and isolated phosphorus adatoms. The latter sequence arises because PH 2 fragments are surprisingly mobile on Si(001) and can diffuse away from the third hydrogen atom that makes up the PH 3 stoichiometry. Our calculated activation energies describe the competition between diffusion and dissociation pathways and hence provide a comprehensive model for the numerous adsorbate species observed in STM experiments

  19. Reaction paths of phosphine dissociation on silicon (001)

    Energy Technology Data Exchange (ETDEWEB)

    Warschkow, O.; McKenzie, D. R. [Centre for Quantum Computation and Communication Technology, School of Physics, The University of Sydney, Sydney, NSW 2006 (Australia); Curson, N. J. [Centre for Quantum Computation and Communication Technology, School of Physics, The University of New South Wales, Sydney, NSW 2052 (Australia); London Centre for Nanotechnology and Department of Electronic and Electrical Engineering, University College London, 17-19 Gordon Street, London WC1H 0AH (United Kingdom); Schofield, S. R. [Centre for Quantum Computation and Communication Technology, School of Physics, The University of New South Wales, Sydney, NSW 2052 (Australia); London Centre for Nanotechnology and Department of Physics and Astronomy, University College, 17-19 Gordon Street, London WC1H 0AH (United Kingdom); Marks, N. A. [Centre for Quantum Computation and Communication Technology, School of Physics, The University of Sydney, Sydney, NSW 2006 (Australia); Discipline of Physics & Astronomy, Curtin University, GPO Box U1987, Perth, WA (Australia); Wilson, H. F. [Centre for Quantum Computation and Communication Technology, School of Physics, The University of Sydney, Sydney, NSW 2006 (Australia); CSIRO Virtual Nanoscience Laboratory, Parkville, VIC 3052 (Australia); School of Applied Sciences, RMIT University, Melbourne, VIC 3000 (Australia); Radny, M. W.; Smith, P. V. [School of Mathematical and Physical Sciences, The University of Newcastle, Callaghan, NSW 2308 (Australia); Reusch, T. C. G.; Simmons, M. Y. [Centre for Quantum Computation and Communication Technology, School of Physics, The University of New South Wales, Sydney, NSW 2052 (Australia)

    2016-01-07

    Using density functional theory and guided by extensive scanning tunneling microscopy (STM) image data, we formulate a detailed mechanism for the dissociation of phosphine (PH{sub 3}) molecules on the Si(001) surface at room temperature. We distinguish between a main sequence of dissociation that involves PH{sub 2}+H, PH+2H, and P+3H as observable intermediates, and a secondary sequence that gives rise to PH+H, P+2H, and isolated phosphorus adatoms. The latter sequence arises because PH{sub 2} fragments are surprisingly mobile on Si(001) and can diffuse away from the third hydrogen atom that makes up the PH{sub 3} stoichiometry. Our calculated activation energies describe the competition between diffusion and dissociation pathways and hence provide a comprehensive model for the numerous adsorbate species observed in STM experiments.

  20. J/ψ dissociation in parity-odd bubbles

    International Nuclear Information System (INIS)

    Tuchin, Kirill

    2011-01-01

    We calculate the quarkonium dissociation rate in the P and CP-odd domains (bubbles) that were possibly created in heavy-ion collisions. In the presence of the magnetic field produced by the valence quarks of colliding ions, parity-odd domains generate electric field. Quarkonium dissociation is the result of quantum tunneling of quark or antiquark through the potential barrier in this electric field. The strength of the electric field in the quarkonium comoving frame depends on the quarkonium velocity with respect to the background magnetic field. We investigate momentum, electric field strength and azimuthal dependence of the dissociation rate. Azimuthal distribution of quarkonia surviving in the electromagnetic field is strongly anisotropic; the form of anisotropy depends on the relation between the electric and magnetic fields and quarkonium momentum P ⊥ . These features can be used to explore the properties of the electromagnetic field created in heavy ion collisions.

  1. Dissociative attachment from vibrationally and rotationally excited HCl and HF

    International Nuclear Information System (INIS)

    Allan, M.; Wong, S.F.

    1981-01-01

    An electron impact mass spectrometer is used to study dissociative attachment in HCl, DCl, and HF at incident energies 0--4 eV. Target molecules in different excited nuclear states are prepared with an iridium oven source. The cross sections for Cl - /HCl, Cl - /DCl, and F - /HF all show an order of magnitude increase with each increase of vibrational quantum (v=0, 1, and 2). In Cl - /HCl the threshold cross section for the v=2 level at 0.1 eV reaches (7.8 +- 4.7) x 10 -15 cm 2 . Together, this large cross section and the recent potential-energy-curve calculations of HCl and HCl - show that the conventional theory of dissociative attachment may not be applicable here. A new mechanism for dissociative attachment is suggested

  2. Photodetachment and dissociation dynamics of microsolvated iodide clusters

    Energy Technology Data Exchange (ETDEWEB)

    Piani, G; Becucci, M [European Laboratory for Non-Linear Spectroscopy, Polo Scientifico e Tecnologico Universita di Firenze, via N Carrara 1, 50019 Sesto Fiorentino (Italy); Bowen, M S; Oakman, J; Hu, Q; Continetti, R E [Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0340 (United States)], E-mail: gpiani@lens.unifi.it, E-mail: becucci@lens.unifi.it, E-mail: rcontinetti@ucsd.edu

    2008-11-15

    The properties of anionic clusters I{sup -}X (X=carbon dioxide, water, ammonia, benzene, phenol, aniline and nitrobenzene) and their dissociation dynamics on the neutral potential energy surface following photodetachment (PD) were studied by photoelectron-photofragment coincidence experiments. Different reaction channels were available using 4.82 eV energy photons, leading to production of iodine in the {sup 2}P{sub 3/2} and {sup 2}P{sub 1/2} states and to both stable and dissociating neutral clusters. The partitioning of the available energy strongly favors the electron kinetic energy channel. The kinetic energy release in the fragment channel is rather small and dependent on the potential energy surface on which the process takes place. A multistep dissociative PD process is observed for the iodide-aniline cluster leading to production of zero kinetic energy electrons.

  3. Dissociative Identity Disorders in Korea: Two Recent Cases.

    Science.gov (United States)

    Kim, Ilbin; Kim, Daeho; Jung, Hyun-Jin

    2016-03-01

    Although dissociative identity disorder (DID), the most severe of the dissociative disorders, has retained its own diagnostic entity since its introduction in the DSM-III, cases of DID are rarely seen in South and East Asia, likely due to the higher prevalence of possession disorder. We report two patients with DID who were recently admitted to our inpatient psychiatric unit and demonstrated distinct transitions to several identities. Their diagnoses were confirmed through a structured interview for dissociative disorders and possible differential diagnoses were ruled out by psychological, neuroimaging, and laboratory tests. The rapid transition to a Westernized, individualized society along with an increase in child abuse, might contribute to an increase in DID, previously under-diagnosed in this region.

  4. Dissociative disorder due to Graves' hyperthyroidism: a case report.

    Science.gov (United States)

    Mizutani, Kaoru; Nishimura, Katsuji; Ichihara, Atsuhiro; Ishigooka, Jun

    2014-01-01

    We report the case of a 20-year-old Japanese woman with no psychiatric history with apparent dissociative symptoms. These consisted of amnesia for episodes of shoplifting behaviors and a suicide attempt, developing together with an exacerbation of Graves' hyperthyroidism. Patients with Graves' disease frequently manifest various psychiatric disorders; however, very few reports have described dissociative disorder due to this disease. Along with other possible causes, for example, encephalopathy associated with autoimmune thyroid disease, clinicians should be aware of this possibility. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Diagnostic challenges leading to underdiagnosis of dissociative disorders

    Directory of Open Access Journals (Sweden)

    Aadil M

    2017-02-01

    Full Text Available Muhammad Aadil,1 Maria Shoaib2 1Department of Psychiatry, Rush University Medical Center, Chicago, IL, USA; 2Department of medicine, Dow Medical College, Karachi, PakistanWe read the article “Is the Dissociative Experiences Scale able to identify detachment and compartmentalization symptoms? Factor structure of the Dissociative Experiences Scale in a large sample of psychiatric and nonpsychiatric subjects” by Mazzotti et al with great interest and would like to add our views in its support.1View the original paper by Mazzotti and colleagues.

  6. Electron-driven excitations and dissociation of molecules

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Greg [Univ. of California, Davis, CA (United States); Orel, Ann E. [Univ. of California, Davis, CA (United States)

    2015-02-13

    This program studied how energy is interchanged in electron and photon collisions with molecules leading to ex-citation and dissociation. Modern ab initio techniques, both for the photoionization and electron scattering, and the subsequent nuclear dynamics studies, are used to accurately treat these problems. This work addresses vibrational ex-citation and dissociative attachment following electron impact, and the dynamics following inner shell photoionzation. These problems are ones for which a full multi-dimensional treatment of the nuclear dynamics is essential and where non-adiabatic effects are expected to be important.

  7. Optical observations of molecular dissociation in thin foils

    International Nuclear Information System (INIS)

    Berry, H.G.; Gay, T.J.; Brooks, R.L.

    1981-01-01

    We have measured the intensity and polarizations of light emitted from atomic excited states of dissociated molecular ions. Using HeH + projectiles, we have observed factors of 1-5 enhancements of the light from n=3, sup(1,3)P,D states of He I and some He II and H I emissions. Observations of Lyman alpha emission after dissociation of H 2 + and H 3 + show rapid variations in light yield for small internuclear separations at the foil surface. (author)

  8. 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.

  9. Photogenerated Exciton Dissociation in Highly Coupled Lead Salt Nanocrystal Assemblies

    KAUST Repository

    Choi, Joshua J.

    2010-05-12

    Internanocrystal coupling induced excitons dissociation in lead salt nanocrystal assemblies is investigated. By combining transient photoluminescence spectroscopy, grazing incidence small-angle X-ray scattering, and time-resolved electric force microscopy, we show that excitons can dissociate, without the aid of an external bias or chemical potential gradient, via tunneling through a potential barrier when the coupling energy is comparable to the exciton binding energy. Our results have important implications for the design of nanocrystal-based optoelectronic devices. © 2010 American Chemical Society.

  10. Dissociative identity disorder and schizophrenia: differential diagnosis and theoretical issues.

    Science.gov (United States)

    Foote, Brad; Park, Jane

    2008-06-01

    Schizophrenia and dissociative identity disorder (DID) are typically thought of as unrelated syndromes--a genetically based psychotic disorder versus a trauma-based dissociative disorder--and are categorized as such by the DSM-IV. However, substantial data exist to document the elevated occurrence of psychotic symptoms in DID; awareness of these features is necessary to prevent diagnostic confusion. Recent research has also pointed out that schizophrenia and DID overlap not only in psychotic symptoms but also in terms of traumatic antecedents, leading to a number of suggestions for revision of our clinical, theoretical, and nosologic understanding of the relationship between these two disorders.

  11. A review of the dissociative disorders: from multiple personality disorder to the posttraumatic stress

    Directory of Open Access Journals (Sweden)

    Modesto J. Romero-López

    Full Text Available In this paper we review the idea of dissociation, dissociative disorders and their relationship with the processes of consciousness. We will deal specifically with multiple personality disorder and posttraumatic stress disorder. Both polarize the discussion of diagnostic categories with dissociative symptoms. This review compares the initial ideas (one century old with the current scenario and emerging trends in research, which are relating cognitive processes and dissociative phenomena and disorders from a neuroscientific approach. We discuss the ideas on dissociation, hypnosis and suicide associated with these disorders. There seems to be a lack of consensus as to the nature of dissociation with theoretical, empirical and clinical implications.

  12. Dissociative disorder manifesting for underlying adolescent hemi-parkinsonism: New chronology for old mummies.

    Science.gov (United States)

    Jha, Shailesh; Garg, Amit; Khanna, Amit

    2015-08-01

    Dissociative symptoms can be induced by a variety of conditions that can either coexist or mimic each other in clinical presentation. In coexisting dissociative disorder with medical illness, the causality remains uncertain, but sometime its role as nidus for dissociative symptoms just cannot be ruled out. The origin of "organic dissociative disorder" is undoubtedly found by various authors who demonstrated that a high percentage of patients with dissociative symptoms present with some form of neurological insult before developing the symptom. Herein we report on a case of adolescent onset hemi-parkinsonism with coexisting dissociative disorder. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. The Dissociative Electroionization of Ammonia and Ammonia-d3. I. The NH+ and NH2+ dissociation channels.

    OpenAIRE

    Locht, Robert; Servais, Christian; Ligot, M.; Derwa, Fr.; Momigny, J.

    1988-01-01

    The dissociative electroionization of NH3 (ND3) in the NH2+ (ND2+) and NH+(ND+) dissociation channels is investigated in the 15-50 eV electron energy range. The translational energy distributions of ND2+ (NH2+) exhibit several components whereas NH+ only shows a continuous broad distribution. For both ions a kinetic energy-versus-appearance energy diagram is obtained and discussed. The predissociation of the Jahn-Teller split NH3+(A2E) state produces both ions at their lowest threshold. At hi...

  14. 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.

  15. Shock wave structure in an ideal dissociating gas

    Science.gov (United States)

    Liu, K. H.

    1975-01-01

    Composition changes within the shock layer due to chemical reactions are considered. The Lighthill ideal dissociating gas model was used in an effort to describe the oxygen type molecule. First, the two limiting cases, when the chemical reaction rates are very slow and very fast in comparison to local convective rates, are investigated. Then, the problem is solved for arbitrary chemical reaction rates.

  16. Structure of light neutron-rich nuclei through Coulomb dissociation

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 57; Issue 2-3. Structure of light neutron-rich nuclei through Coulomb dissociation. U Datta Pramanik T Aumann D Cortina H Emling H Geissel M Hellström R Holzmann N Iwasa Y Leifels G Münzenberg M Rejmund C Scheidenberger K Sümmerer A Leistenschneider ...

  17. Carbon dioxide dissociation and buffering in chicken blood during development.

    Science.gov (United States)

    Tazawa, H; Piiper, J

    1984-07-01

    Carbon dioxide dissociation curves of oxygenated and deoxygenated bloods, the Haldane effect, the buffer value and other blood and true plasma buffering indices, O2 capacity and hematocrit were determined in bloods withdrawn from chicks before, during and after hatching and 8-month-old hens. Blood CO2 dissociation curves shifted upwards in the developing embryo till pipping, and moved downwards after pipping and hatching. In accordance with the position of the CO2 dissociation curves, the true plasma bicarbonate and red cell CO2 standardized to PCO2 = 40 torr changed. The Haldane factor at standard PCO2 increased from 0.12-0.13 on days 10-14 of incubation to 0.34 in young hens. The buffering power changed in parallel with O2 capacity and hematocrit, increasing steadily during incubation, dropping at hatching and then increasing again to the adult value. The observed changes in the CO2 dissociation curves and buffering variables during the development enable the chick to minimize the changes in the acid-base status and are favorable for coping with the increasing demand for CO2 transport and buffering of the developing bird.

  18. Dissociation path for H2 on Al(110)

    DEFF Research Database (Denmark)

    Hammer, Bjørk; Jacobsen, Karsten Wedel; Nørskov, Jens Kehlet

    1992-01-01

    The minimum energy path is calculated for an H2 molecule dissociating on an Al(110) surface within local density functional theory. The properties of the potential energy surface along the five H2 ionic coordinates perpendicular to the reaction path are also determined and shown to be essential...

  19. Clinical Assessment of Dissociative Identity Disorder among College Counseling Clients

    Science.gov (United States)

    Levy, Benjamin; Swanson, Janine E.

    2008-01-01

    College counseling professionals address a wide range of complex student mental health concerns. Among these, accurately identifying client presentations of dissociative identity disorder (DID) can be especially challenging because students with DID sometimes present as if they are experiencing another problem, such as a mood, anxiety, or…

  20. Perseveration induces dissociative uncertainty in obsessive-compulsive disorder.

    Science.gov (United States)

    Giele, Catharina L; van den Hout, Marcel A; Engelhard, Iris M; Dek, Eliane C P; Toffolo, Marieke B J; Cath, Danielle C

    2016-09-01

    Obsessive compulsive (OC)-like perseveration paradoxically increases feelings of uncertainty. We studied whether the underlying mechanism between perseveration and uncertainty is a reduced accessibility of meaning ('semantic satiation'). OCD patients (n = 24) and matched non-clinical controls (n = 24) repeated words 2 (non-perseveration) or 20 times (perseveration). They decided whether this word was related to another target word. Speed of relatedness judgments and feelings of dissociative uncertainty were measured. The effects of real-life perseveration on dissociative uncertainty were tested in a smaller subsample of the OCD group (n = 9). Speed of relatedness judgments was not affected by perseveration. However, both groups reported more dissociative uncertainty after perseveration compared to non-perseveration, which was higher in OCD patients. Patients reported more dissociative uncertainty after 'clinical' perseveration compared to non-perseveration.. Both parts of this study are limited by some methodological issues and a small sample size. Although the mechanism behind 'perseveration → uncertainty' is still unclear, results suggest that the effects of perseveration are counterproductive. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. 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…

  2. Bond dissociation enthalpies of a pinoresinol lignin model compound

    Science.gov (United States)

    Thomas Elder

    2014-01-01

    ABSTRACT: The pinoresinol unit is one of the principal interunit linkages in lignin. As such, its chemistry and properties are of major importance in understanding the behavior or the polymer. This work examines the homolytic cleavage of the pinoresinol system, representing the initial step in thermal degradation. The bond dissociation enthalpy of this reaction has...

  3. Development of a collision induced dissociation ion cyclotron resonance spectrometer

    International Nuclear Information System (INIS)

    Fan, Y.N.

    1982-01-01

    A transient analysis ion cyclotron resonance spectrometer is developed to investigate the phenomena of collision induced dissociation. The Fourier transform method and the modified maximum entropy spectral analysis or covariance least square method are implemented in measuring the mass spectrum of the ion ensemble. The Fourier transform method can be used in quantitative analysis while the maximum entropy method as developed here is useful for qualitative analysis only. The cyclotron resonance frequency, relaxation time constant, and the relative ion population are observable from the Fourier transform spectrum. These parameters are very important in investigating collision induced dissociation process and other topics in gas phase chemistry. The ion cyclotron resonance spectrometer is not only developed to study fragments and their abundance from a parent ion, but also to determine the threshold energy and reaction cross section in the collision induced dissociation process. When hard sphere model is used in the ion-molecule collision, the radius of acetone ion measured from the reactive cross section is 2.2 angstrom which is very close to the physical dimension of acetone. The threshold energy for acetone ion in collision induced dissociation process is 1.8 eV which is similar to the result obtained by the angle-resolved mass spectrometer

  4. Trauma and dissociation in conversion disorder and chronic pelvic pain

    NARCIS (Netherlands)

    Spinhoven, P.; Roelofs, K.; Moene, F.C.; Kuyk, J.; Nijenhuis, E.R.S.; Hoogduin, C.A.L.; Dyck, R. van

    2004-01-01

    Objective: The purpose of this study was to: a) assess the link between sexual and/or physical abuse and dissociation in conversion disorder and chronic pelvic pain patients; and b) assess whether this effect is independent of level of general psychopathology. Method: This report examines data from

  5. Dissociation, Paranormal Belief, and Quality of Life in Older People

    Directory of Open Access Journals (Sweden)

    Tungshan Chou

    2015-12-01

    Full Text Available The measurement of religiosity in current health-related literature is mostly based on the traditional Christian belief system. It has been argued that such a measurement approach may misrepresent the true degree of religiosity in Taiwanese people. In this study, religiosity was measured in two ways: self-reported religion type and a qualitatively derived index of religious piety based on principles as suggested by Gries, Su, and Schak to be used in the Taiwanese context. Their effects on dissociation, paranormal belief, and quality of life were juxtaposed for comparison. In addition, the beneficial effect of religious piety was examined in the framework of McClenon’s ritual healing theory. A total of 266 healthy older adults across Taiwan were interviewed by four trained assistants over a 4-month period. Factor scores were used to represent the dissociative tendencies (depersonalization/derealization, forgetfulness, amnesia, and psychological absorption and paranormal belief facets (precognition, psi power, other forms of life, traditional religious belief, superstition, and telepathy. The results showed that older people of high religious piety display better quality of life profiles than their counterparts in the low religious piety group. The effects of self-reported religion type were mainly seen with paranormal beliefs compatible with their religious beliefs, whereas the effects of religious piety were more pronounced in relation to quality of life than dissociation and paranormal belief. The beneficial advantage of dissociation hypothesized by ritual healing theory did not receive empirical support in the nonclinical sample of this study.

  6. The solvent and substituent effects on bond dissociation energies of ...

    Indian Academy of Sciences (India)

    The solvent and substituent effects on bond dissociation energies of NO-donor molecules containing the N-NO bond ... College of Physics and Engineering, Henan University of Science and Technology, Luoyang 471003 China; Department of Physics and Chemistry, Henan polytechnic University, Jiaozuo 454000 China ...

  7. Electron ionization and dissociation of aliphatic amino acids

    Science.gov (United States)

    Papp, P.; Shchukin, P.; Kočíšek, J.; Matejčík, Š.

    2012-09-01

    We present experimental and theoretical study of electron ionization and dissociative ionization to the gas phase amino acids valine, leucine, and isoleucine. A crossed electron/molecular beams technique equipped with quadrupole mass analyzer has been applied to measure mass spectra and ion efficiency curves for formation of particular ions. From experimental data the ionization energies of the molecules and the appearance energies of the fragment ions were determined. Ab initio calculations (Density Functional Theory and G3MP2 methods) were performed in order to calculate the fragmentation paths and interpret the experimental data. The experimental ionization energies of parent molecules [P]+ 8.91 ± 0.05, 8.85 ± 0.05, and 8.79 ± 0.05 eV and G3MP2 ionization energies (adiabatic) of 8.89, 8.88, and 8.81 eV were determined for valine, leucine, and isoleucine, respectively, as well as the experimental and theoretical threshold energies for dissociative ionization channels. The comparison of experimental data with calculations resulted in identification of the ions as well as the neutral fragments formed in the dissociative reactions. Around 15 mass/charge ratio fragments were identified from the mass spectra by comparison of experimental appearance energies with calculated reaction enthalpies for particular dissociative reactions.

  8. Dissociative experiences and their relationship to mood problems ...

    African Journals Online (AJOL)

    Introduction: To examine the presence of dissociation among Arab mothers with disabled children in Saudi Arabia, and to explore if this is linked to their mood difficulties, in addition to certain other demographic variables. Methods: We conducted a prospective study during the period of June 2011 to February 2012, on 86 ...

  9. Direct measurement of exciton dissociation energy in polymers

    Czech Academy of Sciences Publication Activity Database

    Toušek, J.; Toušková, J.; Chomutová, R.; Paruzel, Bartosz; Pfleger, Jiří

    2017-01-01

    Roč. 7, č. 1 (2017), s. 1-6, č. článku 015113. ISSN 2158-3226 Institutional support: RVO:61389013 Keywords : exciton dissociation energy * polymers * SCR Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 1.568, year: 2016

  10. Mechanism studies on thermal dissociation of tri-n-octylamine ...

    Indian Academy of Sciences (India)

    CHUNHUA DONG

    2017-09-02

    Sep 2, 2017 ... Abstract. The thermal dissociation of tri-n-octylamine hydrochloride (TOAHCl) was investigated using both the quantum chemical simulation and experimental methods. The pathway through which a mixture of tri- n-octylamine (TOA) and hydrogen chloride (HCl), rather than di-n-octylamine (DOA) and ...

  11. Perception, action, and Roelofs effect: a mere illusion of dissociation.

    Directory of Open Access Journals (Sweden)

    Paul Dassonville

    2004-11-01

    Full Text Available A prominent and influential hypothesis of vision suggests the existence of two separate visual systems within the brain, one creating our perception of the world and another guiding our actions within it. The induced Roelofs effect has been described as providing strong evidence for this perception/action dissociation: When a small visual target is surrounded by a large frame positioned so that the frame's center is offset from the observer's midline, the perceived location of the target is shifted in the direction opposite the frame's offset. In spite of this perceptual mislocalization, however, the observer can accurately guide movements to the target location. Thus, perception is prone to the illusion while actions seem immune. Here we demonstrate that the Roelofs illusion is caused by a frame-induced transient distortion of the observer's apparent midline. We further demonstrate that actions guided to targets within this same distorted egocentric reference frame are fully expected to be accurate, since the errors of target localization will exactly cancel the errors of motor guidance. These findings provide a mechanistic explanation for the various perceptual and motor effects of the induced Roelofs illusion without requiring the existence of separate neural systems for perception and action. Given this, the behavioral dissociation that accompanies the Roelofs effect cannot be considered evidence of a dissociation of perception and action. This indicates a general need to re-evaluate the broad class of evidence purported to support this hypothesized dissociation.

  12. Dissociation in hysteria and hypnosis: evidence from cognitive neuroscience.

    Science.gov (United States)

    Bell, Vaughan; Oakley, David A; Halligan, Peter W; Deeley, Quinton

    2011-03-01

    Jean-Martin Charcot proposed the radical hypothesis that similar brain processes were responsible for the unexplained neurological symptoms of 'hysteria', now typically diagnosed as 'conversion disorder' or 'dissociative (conversion) disorder', and the temporary effects of hypnosis. While this idea has been largely ignored, recent cognitive neuroscience studies indicate that (i) hypnotisability traits are associated with a tendency to develop dissociative symptoms in the sensorimotor domain; (ii) dissociative symptoms can be modelled with suggestions in highly hypnotisable subjects; and (iii) hypnotic phenomena engage brain processes similar to those seen in patients with symptoms of hysteria. One clear theme to emerge from the findings is that 'symptom' presentation, whether clinically diagnosed or simulated using hypnosis, is associated with increases in prefrontal cortex activity suggesting that intervention by the executive system in both automatic and voluntary cognitive processing is common to both hysteria and hypnosis. Nevertheless, while the recent literature provides some compelling leads into the understanding of these phenomena, the field still lacks well controlled systematically designed studies to give a clear insight into the neurocognitive processes underlying dissociation in both hysteria and hypnosis. The aim of this review is to provide an agenda for future research.

  13. Theoretical study (ab initio and DFT methods) on acidic dissociation ...

    African Journals Online (AJOL)

    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 ...

  14. C reaction from the Coulomb dissociation of C

    Indian Academy of Sciences (India)

    beam energy within the fully quantum mechanical distorted wave Born approximation formalism of breakup reactions .... [17] of this formalism to nuclear astrophysics was on the Coulomb dissociation of 9Li on. 534. Pramana ..... The approximation involves the replacement of del-operator by an effective local momentum, K(= ...

  15. Multistage audiovisual integration of speech: dissociating identification and detection

    DEFF Research Database (Denmark)

    Eskelund, Kasper; Tuomainen, Jyrki; Andersen, Tobias

    2011-01-01

    signal. Here we show that identification of phonetic content and detection can be dissociated as speech-specific and non-specific audiovisual integration effects. To this end, we employed synthetically modified stimuli, sine wave speech (SWS), which is an impoverished speech signal that only observers...

  16. Physical conditions in Photo-Dissociation Regions around Planetary Nebulae

    NARCIS (Netherlands)

    Bernard-Salas, J; Tielens, A. G. G. M.

    We present observations of the infrared fine-structure lines of [Si II] (34.8 mum), [O I] (63.2 and 145.5 mum) and [C II] (157.7 mum) obtained with the ISO SWS and LWS spectrographs of nine Planetary Nebulae (PNe). These lines originate in the Photo-Dissociation Regions (PDRs) associated with the

  17. Quantum chemical study of mechanisms of dissociation and ...

    Indian Academy of Sciences (India)

    Quantum chemical study of mechanisms of dissociation and isomerization reactions in some molecules and radicals of astrophysical significance: Cyanides and related molecules. V P GUPTA∗ and ARCHNA SHARMA. Department of Physics, University of Jammu, Jammu-Tawi 180 006, India. ∗Corresponding author: ...

  18. Semiempirical and DFT Investigations of the Dissociation of Alkyl Halides

    Science.gov (United States)

    Waas, Jack R.

    2006-01-01

    Enthalpy changes corresponding to the gas phase heats of dissociation of 12 organic halides were calculated using two semiempirical methods, the Hartree-Fock method, and two DFT methods. These calculated values were compared to experimental values where possible. All five methods agreed generally with the expected empirically known trends in the…

  19. The solvent and substituent effects on bond dissociation energies of ...

    Indian Academy of Sciences (India)

    Administrator

    Bond dissociation energy; density functional theory; NO-donor molecule; geometry optimi- zation. 1. Introduction. Nitric oxide (NO) is a simple intra- and intercellular signalling molecule playing important roles in many physiological processes. 1. Its biological functions include regulating the blood pressure, transmitting.

  20. 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

  1. Conversion (dissociative) symptoms as a presenting feature in early onset bipolar disorder: a case series

    OpenAIRE

    Ghosal, Malay Kumar; Guha, Prathama; Sinha, Mausumi; Majumdar, Debabrata; Sengupta, Payel

    2009-01-01

    We present three cases of early onset bipolar disorder where dissociative (conversion) symptoms preceded the onset of mania. This case series underscores the significance of dissociative/conversion symptoms as an early atypical presentation in juvenile bipolar disorder.

  2. Volume of discrete brain structures in complex dissociative disorders : preliminary findings

    NARCIS (Netherlands)

    Ehling, T.; Nijenhuis, E. R. S.; Krikke, A. P.; DeKloet, ER; Vermetten, E

    2007-01-01

    Based on findings in traumatized animals and patients with posttraumatic stress disorder, and on traumatogenic models of complex dissociative disorders, it was hypothesized that (1) patients with complex dissociative disorders have smaller volumes of hippocampus, parahippocampal gyrus, and amygdala

  3. 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

  4. Experimental measurements and thermodynamic modeling of refrigerant hydrates dissociation conditions

    International Nuclear Information System (INIS)

    Hashemi, Hamed; Babaee, Saeedeh; Mohammadi, Amir H.; Naidoo, Paramespri; Ramjugernath, Deresh

    2015-01-01

    Highlights: • Dissociation conditions of refrigerant hydrates are studied experimentally and theoretically. • Refrigerants R23, R134a, R125a, R22, R410A, R407C and R507C are studied experimentally. • A thermodynamic model able to predict refrigerant hydrates dissociation conditions is proposed. • The results show good agreement between the experimental and predicted values. - Abstract: This study aims to investigate dissociation conditions of refrigerant hydrates both experimentally and theoretically. For this purpose, dissociation conditions of refrigerants R23, R134a, R125a, R22, R410A, R407C and R507C have been measured experimentally. A thermodynamic model that is able to predict refrigerant hydrates dissociation conditions in the various phase equilibrium regions has been proposed as well. Refrigerants modeled in this study include pure refrigerants: R11, R12, R13, R22, R23, R32, R134a, R141b, R143a, R125a, R152a, and mixed refrigerants: R11 + R12, R11 + R114, R12 + R114, R32 + R125a + R134a (R407C), R32 + R125a (R410A). For the modeling of the fluid and hydrate phases, the Peng-Robinson equation of state modified by Stryjek and Vera and the MHV2 G E -EoS mixing rule along with the UNIFAC (original) activity coefficient and van der Waals–Platteeuw (vdW–P) models were employed. The results show good agreement between the experimental and predicted values

  5. Dissociação e transtornos dissociativos: modelos teóricos Dissociation and dissociative disorders: theoretical models

    Directory of Open Access Journals (Sweden)

    Paulo Jacomo Negro Junior

    1999-12-01

    Full Text Available A compreensão da experiência dissociativa e das origens dos transtornos dissociativos é difícil devido à complexidade da questão. As contradições da classificação são decorrentes das dificuldades de se construir uma teoria da mente abrangente que unifique neurobiologia e psicodinâmica. Os autores discutem as bases conceituais da dissociação com ênfase na integração entre neurobiologia e fenomenologia. O papel do aprendizado é amplamente discutido, assim como as teorias atuais de neodissociação, trauma e sociocognitivismo para os transtornos dissociativos.It is challenging to understand the dissociative experiences and the origins of dissociative disorders. Contradictions of classification are due to the intrinsic difficulties to build up a theory of the mind that unifies neurobiology and psychodynamics. The authors discuss the conceptual basis of dissociation, with emphasis on the integration of neurobiology and phenomenology. The role of learning is discussed as well as the neodissociative, trauma, and sociocognitive theories for dissociative disorders.

  6. Probing the potential energy landscape for dissociation of protonated indole via threshold collision-induced dissociation and theoretical studies

    Science.gov (United States)

    Yang, Zhibo; Ruan, Chunhai; Ahmed, H.; Rodgers, M. T.

    2007-09-01

    Collision-induced dissociation of protonated indole with Xe is studied as a function of kinetic energy using guided ion beam tandem mass spectrometry techniques. Activated dissociation resulting in endothermic loss of neutral HCN (or HNC) is the only pathway observed over the range of collision energies examined. The cross-section threshold for this activated dissociation pathway is interpreted to yield 0 and 298 K activation energies for this process after accounting for the effects of multiple ion-neutral collisions, the internal energy distribution of the protonated indole cations, and their lifetimes for dissociation. Density functional theory (DFT) calculations at the MPW1PW91/6-31G* level of theory are used to determine the structures of indole, the protonated indole tautomers, and the transition states, intermediates, and products involved in the activated dissociation of protonated indole. Four distinct pathways between the reactant ion and dissociation products are computed. In all cases, the ionic product formed is C6H5CH2+, while the neutral product is HCN in three of the pathways and HNC in the fourth. The vibrational frequencies and rotational constants of the ground state tautomer of protonated indole and the rate-determining transition state along each of the pathways computed are used for the thermodynamic analysis of the experimental data. The theoretical activation energies and potential energy landscapes for activated dissociation of protonated indole are determined from single point calculations at the MPW1PW91/6-311+G(2d,2p) and MP2(full)/6-311+G(2d,2p) levels of theory, using the MPW1PW91/6-31G* optimized geometries. Both theories produce similar potential energy landscapes for elimination of HCN (or HNC) from protonated indole. Theory suggests that elimination of HNC is favored over HCN. However, our threshold measurements probe the lowest-energy pathway available and are in much better agreement with the higher-energy HCN elimination

  7. 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.

  8. 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.

  9. CO dissociation on Ni: The effect of steps and of nickel carbonyl

    DEFF Research Database (Denmark)

    Engbæk, Jakob; Lytken, Ole; Nielsen, Jane Hvolbæk

    2008-01-01

    The dissociation of CO was investigated on a stepped Ni(141313) crystal. The experiments show that the monoatomic steps completely dominate the dissociation of CO on the nickel surface. The activation energy for dissociation of CO along the steps is measured at 500 K to be 150 kJ/mol in the press...... and in the Fischer-Tropsch synthesis....

  10. Multidimensional Potential Energy Surface for H2 Dissociation over Cu(111)

    DEFF Research Database (Denmark)

    Hammer, Bjørk; Scheffler, Matthias; Jacobsen, Karsten Wedel

    1994-01-01

    We present ab initio density functional calculations within the generalized gradient approximation for H-2 dissociating over Cu(111). The minimum barrier for dissociation is 0.5 eV and shows large corrugation within the unit cell and a strong dependence on the molecular orientation. Dissociation ...

  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. 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…

  13. Dissociation and memory fragmentation: Experimental effects on meta-memory but not on actual memory performance.

    NARCIS (Netherlands)

    van den Hout, M.; Kindt, M.

    2003-01-01

    The relation between state dissociation and fragmentary memory was investigated by assessing both actual memory performance and meta-memory. From a sample of 330 normal subjects, 2 subsamples were selected on basis of trait dissociation, as measured by the Dissociative Experience Scale. 20 subjects

  14. The Phenomenon of Pathological Dissociation in the Ancient Chinese Medicine Literature.

    Science.gov (United States)

    Fung, Hong Wang

    2018-01-01

    Dissociative symptoms and disorders have been reported in many different cultures. If pathological dissociation is naturally occurring and related to adverse experiences, such phenomena should have been witnessed and portrayed before the modern age. To investigate whether this is the case, the author made use of the rich ancient Chinese medicine literature and looked for descriptions of pathological dissociation in medical documents written by ancient Chinese medical practitioners. In this paper, the author presents six cases selected from the ancient Chinese medicine literature. The phenomenon of pathological dissociation is observed in these cases. This is the first report of case descriptions of pathological dissociation documented in Chinese cultures before 1900.

  15. Dissociative stupor mimicking consciousness disorder in an advanced lung cancer patient.

    Science.gov (United States)

    Tada, Yukio; Okano, Tetsuya; Kaga, Akiko; Yamazaki, Susumu; Kawada, Satoshi; Ishida, Mayumi; Kobayashi, Kunihiko; Onishi, Hideki

    2012-06-01

    Although there are three kinds of stupor in psychiatry, dissociative stupor is the most commonly recognized. In psychiatric clinics or emergency rooms, dissociative stupor is common, but in an oncology setting it is hardly known. Therefore, distinguishing dissociative stupor from consciousness disorder is occasionally difficult, especially in the advanced or terminal phase. We report an advanced lung cancer patient who presented dissociative stupor mimicking consciousness disorder. It is necessary to distinguish between consciousness disorder and dissociative stupor. In addition, consultation with a psychiatrist should be taken into consideration.

  16. Who Done It, Actually? Dissociative Identity Disorder for the Criminologist

    Directory of Open Access Journals (Sweden)

    Adah Sachs

    2015-07-01

    Full Text Available Dissociative Identity Disorder (DID (American Psychiatric Association 2013 is examined in this paper from the perspective of its relevance to the criminologist. As this psychiatric condition is linked to severe and prolonged childhood abuse, accounts of DID patients inevitably involve reports of serious crimes, in which the person was the victim, perpetrator or witness. These reports can thus contain crucial information for criminal investigations by the police or for court proceedings. However, due to the person’s dissociation, such reports are often very confusing, hard to follow, hard to believe and difficult to obtain. They also frequently state that the person had ‘no choice’, a thorny notion for the criminologist (as well as for the clinician. Through the analysis of clinical examples, the paper explores how decisions are made by a person with DID, the notions of choice and ‘competent reasoning’, and the practical and ethical ways for interviewing a person with DID.

  17. Dissociative excitation and fragmentation of S8 by electron impact.

    Science.gov (United States)

    Brotton, S J; McConkey, J W

    2011-05-28

    The vacuum-ultraviolet emission spectrum from 136 nm to 168 nm following the dissociative excitation of a predominantly S(8) target by electron impact at 100 eV incident energy was measured. The relative cross sections for the dominant multiplets at 138.9, 142.9, 147.9, and 166.7 nm are presented. Excitation functions are shown for electron-impact energies from below threshold to 360 eV for the two most prominent emissions at 142.5 nm and 147.4 nm. Five thresholds are clearly apparent in both excitation functions. For the four highest energy channels, the energy separation between the adjacent thresholds is approximately constant and the cross sections reduce regularly as the threshold energies increase. We suggest possible fragmentation pathways of the dissociating S(8) molecule that reproduce the energies of our observed thresholds. © 2011 American Institute of Physics

  18. Dissociative ionization of ethane with femtosecond pulses of radiation

    Science.gov (United States)

    Boran, Y.; Gutsev, G. L.; Kolomenskii, A. A.; Zhu, F.; Schuessler, A.; Strohaber, J.

    2018-02-01

    We present results of the interaction of ethane with 50 fs pulses of radiation at a wavelength of 800 nm. Ion yields of the parent ion and daughter fragments were measured using a reflectron time-of-flight (TOF) mass spectrometer. The yields of dissociative ionization products were measured as a function of laser intensity and polarization angle. Intensity scans indicate sequential ionization and dissociation. When the field polarization was rotated with respect to the TOF axis, we observed anisotropic ion yields of fragment ions peaked along the TOF axis. Measurements of the fragment {{{C}}}2{{{{H}}}2}2+ reveal the existence of anomalous perpendicular fragmentation. Kinetic energy of the hydrogen ions was measured using linear operation of the TOF and provided information on the underlying mechanisms for formation of H+, {{{{H}}}2}+ and {{{{H}}}3}+. Quantum chemical calculations using GAUSSIAN 09 further investigated the production of {{{{H}}}3}+ and the stability of C2H2+.

  19. Threshold collision induced dissociation experiment for azobenzene and its derivatives

    Science.gov (United States)

    Rezaee, Mohammadreza; Compton, Robert

    In this study we investigated protonated azobenzene cation and properties of trans 2,2',6,6'-tetrafluoroazobenzene anion using the collision induced dissociation method and the results are compared with the results from ab initio electronic structure calculations. We measured the bond dissociation energies experimentally and found which theoretical quantum chemistry methods yield best results. Several high accuracy multi-level calculations such as CBS-QB3, G3 and G4 had been carried out to obtain reliable thermochemical information for azobenzene and several of its derivatives and their anion or cation. We also performed other experiments such as Raman spectroscopy to study these light sensitive molecules with promising applications such as photo-switching.

  20. Wave-packet approach to Rydberg resonances in dissociative recombination

    International Nuclear Information System (INIS)

    Morisset, Sabine; Pichl, Lukas; Orel, Ann E.; Schneider, Ioan F.

    2007-01-01

    We report the time-dependent approach to resonant electron capture into Rydberg states in collisions with molecular cations at low impact energy, as an alternative to the method based on multichannel quantum defect theory (MQDT), and present the results for the HD + ion. The propagation of the initial wave function on 13 Rydberg states (besides one valence state) correctly describes the indirect dissociative recombination mechanism in the time domain. Notably, the nonlocal coupling operator between the ionization and dissociation channels is accounted for in the indirect process, extending previous work on the case of direct coupling. The present approach compares to the MQDT framework with remarkable precision: resonant structures in the cross section correctly emerge from the wave-packet propagation; the time-dependent result also forms a cross section envelope for the dense series of ultrafine MQDT resonances corresponding to the quasicontinuous part of the Rydberg state manifold

  1. Post-foil interaction in foil-induced molecular dissociation

    International Nuclear Information System (INIS)

    Faibis, A.; Kanter, E.P.; Koenig, W.; Plesser, I.; Vager, Z.

    1985-01-01

    The authors have investigated the foil-induced dissociation of 175- 250- keV/amu CH + , NH + , and OH + , FH + and NeH + ions by coincident detection of the fragment atoms. The dissociation energies corresponding to in-foil and post-foil interactions were deduced from the measured relative flight times of the fragment pairs to a set of detectors downstream from the target. The authors considered final states consisting of a) a proton and a heavy-ion and, b) a hydrogen atom and a heavy-ion. Surprisingly, in both cases the energy released in the post-target interaction shows a similar linear increase with the charge state of the heavy partner

  2. Accurate bond dissociation energies (D 0) for FHF- isotopologues

    Science.gov (United States)

    Stein, Christopher; Oswald, Rainer; Sebald, Peter; Botschwina, Peter; Stoll, Hermann; Peterson, Kirk A.

    2013-09-01

    Accurate bond dissociation energies (D 0) are determined for three isotopologues of the bifluoride ion (FHF-). While the zero-point vibrational contributions are taken from our previous work (P. Sebald, A. Bargholz, R. Oswald, C. Stein, P. Botschwina, J. Phys. Chem. A, DOI: 10.1021/jp3123677), the equilibrium dissociation energy (D e ) of the reaction ? was obtained by a composite method including frozen-core (fc) CCSD(T) calculations with basis sets up to cardinal number n = 7 followed by extrapolation to the complete basis set limit. Smaller terms beyond fc-CCSD(T) cancel each other almost completely. The D 0 values of FHF-, FDF-, and FTF- are predicted to be 15,176, 15,191, and 15,198 cm-1, respectively, with an uncertainty of ca. 15 cm-1.

  3. Dissociative electron attachment: Threshold phenomena and multimode effects

    International Nuclear Information System (INIS)

    Fabrikant, Ilya I

    2009-01-01

    We present a summary of recent progress on studies of threshold phenomena in low-energy dissociative electron attachment to polyatomic molecules: vibrational Feshbach resonances and threshold cusps. The theoretical approach is based on the resonance R-matrix theory. It allows us to analyze threshold effects in other channels, particularly vibrational excitation. If the molecular long-range field is not strong enough, virtual-state cusps are observed at vibrational excitation thresholds. The second part of the paper illustrates the multimode effects in dissociative attachment using attachment to the CF 3 Cl molecule as an example. Symmetric stretch C-Cl vibrations v 3 and symmetric deformation (or so-called u mbrella ) vibrations v 2 are included. Calculations allow us to study the final-state vibrational distribution in the CF 3 (v 2 ) fragment.

  4. 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.

  5. Comparison of brazilian spiritist mediumship and dissociative identity disorder.

    Science.gov (United States)

    Moreira-Almeida, Alexander; Neto, Francisco Lotufo; Cardeña, Etzel

    2008-05-01

    We studied the similarities and differences between Brazilian Spiritistic mediums and North American dissociative identity disorder (DID) patients. Twenty-four mediums selected among different Spiritistic organizations in São Paulo, Brazil, were interviewed using the Dissociative Disorder Interview Schedule, and their responses were compared with those of DID patients described in the literature. The results from Spiritistic mediums were similar to published data on DID patients only with respect to female prevalence and high frequency of Schneiderian first-rank symptoms. As compared with individuals with DID, the mediums differed in having better social adjustment, lower prevalence of mental disorders, lower use of mental health services, no use of antipsychotics, and lower prevalence of histories of physical or sexual childhood abuse, sleepwalking, secondary features of DID, and symptoms of borderline personality. Thus, mediumship differed from DID in having better mental health and social adjustment, and a different clinical profile.

  6. Convergent paradigms for visual neuroscience and dissociative identity disorder.

    Science.gov (United States)

    Manning, Mark L; Manning, Rana L

    2009-01-01

    Although dissociative identity disorder, a condition in which multiple individuals appear to inhabit a single body, is a recognized psychiatric disorder, patients may yet encounter health professionals who declare that they simply "do not believe in multiple personalities." This article explores the proposal that resistance to the disorder represents a failure to apply an appropriate paradigm from which the disorder should be interpreted. Trauma and sociocognitive explanations of dissociative identity disorder are contrasted. The trauma hypothesis is further differentiated into paradigms in which trauma affects a defense mechanism, and one in which trauma serves to inhibit the normal integration sequence of parallel processes of the self in childhood. This latter paradigm is shown to be broadly consistent with current models of cortical processing in another system, the cortical visual system.

  7. 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.

  8. 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).

  9. Dissociation mediates the relationship between childhood trauma and hallucination-proneness.

    Science.gov (United States)

    Varese, F; Barkus, E; Bentall, R P

    2012-05-01

    It has been proposed that the relationship between childhood trauma and hallucinations can be explained by dissociative processes. The present study examined whether the effect of childhood trauma on hallucination-proneness is mediated by dissociative tendencies. In addition, the influence of dissociative symptoms on a cognitive process believed to underlie hallucinatory experiences (i.e. reality discrimination; the capacity to discriminate between internal and external cognitive events) was also investigated. Patients with schizophrenia spectrum disorders (n=45) and healthy controls (with no history of hallucinations; n=20) completed questionnaire measures of hallucination-proneness, dissociative tendencies and childhood trauma, as well as performing an auditory signal detection task. Compared to both healthy and non-hallucinating clinical controls, hallucinating patients reported both significantly higher dissociative tendencies and childhood sexual abuse. Dissociation positively mediated the effect of childhood trauma on hallucination-proneness. This mediational role was particularly robust for sexual abuse over other types of trauma. Signal detection abnormalities were evident in hallucinating patients and patients with a history of hallucinations, but were not associated with pathological dissociative symptoms. These results are consistent with dissociative accounts of the trauma-hallucinations link. Dissociation, however, does not affect reality discrimination. Future research should examine whether other cognitive processes associated with both dissociative states and hallucinations (e.g. deficits in cognitive inhibition) may explain the relationship between dissociation and hallucinatory experiences.

  10. Automated tissue dissociation for rapid extraction of viable cells

    OpenAIRE

    McBeth, Christine; Gutermuth, Angela; Ochs, Jelena; Sharon, Andre; Sauer-Budge, Alexis F.

    2017-01-01

    Viable cells from healthy tissues are a rich resource in high demand for many next-generation therapeutics and regenerative medicine applications. Cell extraction from the dense connective matrix of most tissues is a labor-intensive task and high variability makes cGMP compliance difficult. To reduce costs and ensure greater reproducibility, automated tissue dissociators compatible with robotic liquid handling systems are required. Here we demonstrate the utility of our automated tissue disso...

  11. Dissociation of weak acids during Gran plot free acidity titrations

    OpenAIRE

    Lindberg, Steven E:; Cole, Jan M.

    2011-01-01

    A comparison of weak and free acid concentrations measured by base titration and hydrogen ionactivities determined by direct pH measurement is described for several of our data sets for raincollected above and below a forest canopy in the eastern United States. These data illustrate theinfluence of weak acid dissociation during titration and the possible effect of activity coefficientson calculated free acid concentrations.DOI: 10.1111/j.1600-0889.1984.tb00240.x

  12. Dissociative recombination of interstellar ions: electronic structure calculations for HCO+

    International Nuclear Information System (INIS)

    Kraemer, W.P.; Hazi, A.U.

    1985-01-01

    The present study of the interstellar formyl ion HCO + is the first attempt to investigate dissociative recombination for a triatomic molecular ion using an entirely theoretical approach. We describe a number of fairly extensive electronic structure calculations that were performed to determine the reaction mechanism of the e-HCO + process. Similar calculations for the isoelectronic ions HOC + and HN 2 + are in progress. 60 refs

  13. [Dissociating between Enhancing and Impairing Effects of Emotion on Cognition].

    Science.gov (United States)

    Dolcos, Florin; Denkova, Ekaterina

    Objectives Emerging evidence suggests that emotion can have both enhancing and impairing effects on various cognitive processes. These opposing effects can be identified at different levels, both within the same cognitive process and across different processes, as well as at more general levels, such as in the case of the response to stress. The aim of the present review is to discuss recent advances in the mechanisms underlying the enhancing and impairing effects of emotion on different aspects within the same process (e.g., episodic memory) and across specific cognitive processes (perception vs. episodic memory, working memory vs. episodic memory), as well as in the context of the response to stress.Emerging Evidence The available evidence points to a number of aspects that dissociate the opposing effects of emotion on cognition. (i) Opposing effects within episodic memory can be attributed to different accounts, involving dissociation at different levels: central vs. peripheral trade-off, high vs. low prioritization of information processing, and items encoding vs. the formation of complex associations. (ii) The opposing effects across cognitive processes, such as perception and episodic memory, can be linked to dissociation between immediate/impairing vs. long-term/enhancing effects, which are mediated by common and dissociable neural mechanisms, involving bottom-up and top-down processes. (iii) Finally, in the larger context of the response to stress, emotional stress can lead to opposing effects depending on the degree, context, and controllability of the stressors.Conclusions Overall, the present review highlights the need to consider the various factors that can influence enhancing or impairing effects of emotion on cognition, in studies investigating emotion-cognition interactions. These issues are important for understanding mechanisms of emotion-cognition interactions not only in healthy functioning but also in emotional disturbances, where these

  14. Obesity and dissociable forms of impulsivity in young adults.

    OpenAIRE

    Chamberlain, Sam; Derbyshire, Katherine L; Leppink, Eric; Grant, Jon E

    2015-01-01

    Objective. Obesity is one of the leading causes of preventable morbidity and mortality, and young people are increasingly affected. The aim of this study was to examine relationships between obesity and dissociable forms of impulsivity in young adults. Methods. A group of young adults (511) was recruited from city areas in the United States using media advertisements. These young adults were administered careful and extensive clinical and neurocognitive assessment in order to quantif...

  15. [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.

  16. Co-occurrence of dissociative identity disorder and borderline personality disorder.

    Science.gov (United States)

    Ross, Colin A; Ferrell, Lynn; Schroeder, Elizabeth

    2014-01-01

    The literature indicates that, among individuals with borderline personality disorder, pathological dissociation correlates with a wide range of impairments and difficulties in psychological function. It also predicts a poorer response to dialectical behavior therapy for borderline personality disorder. We hypothesized that (a) dissociative identity disorder commonly co-occurs with borderline personality disorder and vice versa, and (b) individuals who meet criteria for both disorders have more comorbidity and trauma than individuals who meet criteria for only 1 disorder. We interviewed a sample of inpatients in a hospital trauma program using 3 measures of dissociation. The most symptomatic group was those participants who met criteria for both borderline personality disorder and dissociative identity disorder on the Dissociative Disorders Interview Schedule, followed by those who met criteria for dissociative identity disorder only, then those with borderline personality disorder only, and finally those with neither disorder. Greater attention should be paid to the relationship between borderline personality disorder and dissociative identity disorder.

  17. Dissociation and symptoms of culture-bound syndromes in North America: a preliminary study.

    Science.gov (United States)

    Ross, Colin A; Schroeder, Elizabeth; Ness, Laura

    2013-01-01

    The aim of this study was to determine whether classical culture-bound syndromes occur among psychiatric inpatients with dissociative disorders in North America. The Dissociative Trance Disorder Interview Schedule, the Dissociative Experiences Scale, and the Dissociative Disorders Interview Schedule were administered to 100 predominantly Caucasian, American, English-speaking trauma program inpatients at a hospital in the United States. The participants reported high rates of childhood physical and/or sexual abuse (87%), dissociative disorders (73%), and membership in the dissociative taxon (78%). They also reported a wide range of possession experiences and exorcism rituals, as well as the classical culture-bound syndromes of latah, bebainan, amok, and pibloktoq. Our data are consistent with the view that possession and classical culture-bound syndromes are predominantly dissociative in nature and not really culture-bound from the perspective of Caucasian, English-speaking America.

  18. Stability Analysis of Methane Hydrate-Bearing Soils Considering Dissociation

    Directory of Open Access Journals (Sweden)

    Hiromasa Iwai

    2015-06-01

    Full Text Available It is well known that the methane hydrate dissociation process may lead to unstable behavior such as large ground deformations, uncontrollable gas production, etc. A linear instability analysis was performed in order to investigate which variables have a significant effect on the onset of the instability behavior of methane hydrate-bearing soils subjected to dissociation. In the analysis a simplified viscoplastic constitutive equation is used for the soil sediment. The stability analysis shows that the onset of instability of the material system mainly depends on the strain hardening-softening parameter, the degree of strain, and the permeability for water and gas. Then, we conducted a numerical analysis of gas hydrate-bearing soil considering hydrate dissociation in order to investigate the effect of the parameters on the system. The simulation method used in the present study can describe the chemo-thermo-mechanically coupled behaviors such as phase changes from hydrates to water and gas, temperature changes and ground deformation. From the numerical results, we found that basically the larger the permeability for water and gas is, the more stable the simulation results are. These results are consistent with those obtained from the linear stability analysis.

  19. Quantum entanglement and the dissociation process of diatomic molecules

    Energy Technology Data Exchange (ETDEWEB)

    Esquivel, Rodolfo O; Molina-Espiritu, Moyocoyani [Departamento de Quimica, Universidad Autonoma Metropolitana, 09340-Mexico DF (Mexico); Flores-Gallegos, Nelson [Unidad Profesional Interdisciplinaria de IngenierIa, Campus Guanajuato del Instituto Politecnico Nacional, 36275-Guanajuato (Mexico); Plastino, A R; Angulo, Juan Carlos; Dehesa, Jesus S [Instituto Carlos I de Fisica Teorica y Computacional, and Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Granada, 18071-Granada (Spain); Antolin, Juan, E-mail: esquivel@xanum.uam.mx, E-mail: arplastino@ugr.es [Departamento de Fisica Aplicada, EUITIZ, Universidad de Zaragoza, 50018-Zaragoza (Spain)

    2011-09-14

    In this work, we investigate quantum entanglement-related aspects of the dissociation process of some selected, representative homo- and heteronuclear diatomic molecules. This study is based upon high-quality ab initio calculations of the (correlated) molecular wavefunctions involved in the dissociation processes. The values of the electronic entanglement characterizing the system in the limit cases corresponding to (i) the united-atom representation and (ii) the asymptotic region when atoms dissociate are discussed in detail. It is also shown that the behaviour of the electronic entanglement as a function of the reaction coordinate R exhibits remarkable correspondences with the phenomenological description of the physically meaningful regimes comprising the processes under study. In particular, the extrema of the total energies and the electronic entanglement are shown to be associated with the main physical changes experienced by the molecular spatial electronic density, such as charge depletion and accumulation or bond cleavage regions. These structural changes are characterized by several selected descriptors of the density, such as the Laplacian of the electronic molecular distributions (LAP), the molecular electrostatic potential (MEP) and the atomic electric potentials fitted to the MEP.

  20. Quantum entanglement and the dissociation process of diatomic molecules

    International Nuclear Information System (INIS)

    Esquivel, Rodolfo O; Molina-Espiritu, Moyocoyani; Flores-Gallegos, Nelson; Plastino, A R; Angulo, Juan Carlos; Dehesa, Jesus S; Antolin, Juan

    2011-01-01

    In this work, we investigate quantum entanglement-related aspects of the dissociation process of some selected, representative homo- and heteronuclear diatomic molecules. This study is based upon high-quality ab initio calculations of the (correlated) molecular wavefunctions involved in the dissociation processes. The values of the electronic entanglement characterizing the system in the limit cases corresponding to (i) the united-atom representation and (ii) the asymptotic region when atoms dissociate are discussed in detail. It is also shown that the behaviour of the electronic entanglement as a function of the reaction coordinate R exhibits remarkable correspondences with the phenomenological description of the physically meaningful regimes comprising the processes under study. In particular, the extrema of the total energies and the electronic entanglement are shown to be associated with the main physical changes experienced by the molecular spatial electronic density, such as charge depletion and accumulation or bond cleavage regions. These structural changes are characterized by several selected descriptors of the density, such as the Laplacian of the electronic molecular distributions (LAP), the molecular electrostatic potential (MEP) and the atomic electric potentials fitted to the MEP.

  1. Predictions of hydrate plug dissociation with electrical heating

    Energy Technology Data Exchange (ETDEWEB)

    Davies, S.R.; Ivanic, J.; Sloan, E.D.

    2005-07-01

    The rate of dissociation for cylindrical hydrate plugs by the application of radial electrical heating was investigated for structure I and structure II hydrates for pressures of 7 MPa (1000 psia) and 14 MPa (2000 psia). Heating rates of 2.3 kWm{sup -3}, 4.5 kWm-3 and 6.8 kWm{sup -3} were investigated for a plug 91.4 cm (36 inches) in length and 2.54 cm (1 inch) in diameter. A heat transfer model was developed in cylindrical coordinates based on Fourier's Law with a boundary condition of constant heat flux at the pipe wall. The equation set was solved numerically using a finite difference grid and the standard explicit scheme. The model was found to replicate well the experimental observations with no fitted parameters. A computer program was formulated to allow the practicing engineer to simulate the dissociation of industrial hydrates with minimal complexity. This program was incorporated into the latest version of our CSMPlug program which has been used by a number of energy companies to predict hydrate plug dissociation rates in the field. (Author)

  2. Neurodevelopmental origins of abnormal cortical morphology in dissociative identity disorder.

    Science.gov (United States)

    Reinders, A A T S; Chalavi, S; Schlumpf, Y R; Vissia, E M; Nijenhuis, E R S; Jäncke, L; Veltman, D J; Ecker, C

    2018-02-01

    To examine the two constitutes of cortical volume (CV), that is, cortical thickness (CT) and surface area (SA), in individuals with dissociative identity disorder (DID) with the view of gaining important novel insights into the underlying neurobiological mechanisms mediating DID. This study included 32 female patients with DID and 43 matched healthy controls. Between-group differences in CV, thickness, and SA, the degree of spatial overlap between differences in CT and SA, and their relative contribution to differences in regional CV were assessed using a novel spatially unbiased vertex-wise approach. Whole-brain correlation analyses were performed between measures of cortical anatomy and dissociative symptoms and traumatization. Individuals with DID differed from controls in CV, CT, and SA, with significantly decreased CT in the insula, anterior cingulate, and parietal regions and reduced cortical SA in temporal and orbitofrontal cortices. Abnormalities in CT and SA shared only about 3% of all significantly different cerebral surface locations and involved distinct contributions to the abnormality of CV in DID. Significant negative associations between abnormal brain morphology (SA and CV) and dissociative symptoms and early childhood traumatization (0 and 3 years of age) were found. In DID, neuroanatomical areas with decreased CT and SA are in different locations in the brain. As CT and SA have distinct genetic and developmental origins, our findings may indicate that different neurobiological mechanisms and environmental factors impact on cortical morphology in DID, such as early childhood traumatization. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. High-order above-threshold dissociation of molecules

    Science.gov (United States)

    Lu, Peifen; Wang, Junping; Li, Hui; Lin, Kang; Gong, Xiaochun; Song, Qiying; Ji, Qinying; Zhang, Wenbin; Ma, Junyang; Li, Hanxiao; Zeng, Heping; He, Feng; Wu, Jian

    2018-03-01

    Electrons bound to atoms or molecules can simultaneously absorb multiple photons via the above-threshold ionization featured with discrete peaks in the photoelectron spectrum on account of the quantized nature of the light energy. Analogously, the above-threshold dissociation of molecules has been proposed to address the multiple-photon energy deposition in the nuclei of molecules. In this case, nuclear energy spectra consisting of photon-energy spaced peaks exceeding the binding energy of the molecular bond are predicted. Although the observation of such phenomena is difficult, this scenario is nevertheless logical and is based on the fundamental laws. Here, we report conclusive experimental observation of high-order above-threshold dissociation of H2 in strong laser fields where the tunneling-ionized electron transfers the absorbed multiphoton energy, which is above the ionization threshold to the nuclei via the field-driven inelastic rescattering. Our results provide an unambiguous evidence that the electron and nuclei of a molecule as a whole absorb multiple photons, and thus above-threshold ionization and above-threshold dissociation must appear simultaneously, which is the cornerstone of the nowadays strong-field molecular physics.

  4. Representative oxygen dissociation curve and equation for the chicken.

    Science.gov (United States)

    Boyd, R L; McDaniel, G R; Clark, C H

    1981-01-01

    Because of the considerable variability in the oxygen dissociation curves for chickens reported in the literature, the respiratory physiologist studying avian gas exchange is faced with the dilemma of which curve is representative for the chicken. In order to arrive at a representative curve, data from eight reported curves were compiled and adjusted to the same set of standard conditions of temperature (T), pH, and partial pressure of carbon dioxide (PCO2): T = 42 C, pH = 7.5 PCO2 = 40 torr. The mean PO2 STD (mean +/- SD) versus percent saturation of hemoglobin curve was then determined. The mean data were fitted to an equation representing the oxygen dissociation curve so that for any selected partial pressure of oxygen (PO2) the percent saturation (%SAT) of oxyhemoglobin may be computed. The P50 values for the mean literature and equation curves, respectively, were 47.4 +/- 9.8 and 45.3 Torr. The mean curve with its standard deviations provides a chicken oxygen dissociation curve representative of the literature data to which experimental data may be compared. The equation for the curve enables rapid referral to the representative curve to compute the %SAT, given the PO2 adjusted to the standard conditions.

  5. Association and dissociation of Feshbach molecules in a microgravity environment

    Science.gov (United States)

    D'Incao, Jose P.; Willians, Jason R.

    2016-05-01

    NASA's Cold Atom Laboratory (CAL) is a multi-user facility scheduled for launch to the ISS in 2017. Our flight experiments with CAL will characterize and mitigate leading-order systematics in dual-atomic-species atom interferometers in microgravity relevant for future fundamental physics missions in space. Here, we study the RF association and dissociation of weakly bound heteronuclear Feshbach molecules for expected parameters relevant for the microgravity environment of CAL. This includes temperatures on the pico-Kelvin range and atomic densities as low as 108/ cm3. We show that under such conditions, thermal and loss effects can be greatly suppressed, resulting in high efficiency in both association and dissociation of extremely weakly bound Feshbach molecules and allowing for high accuracy determination coherent properties of such processes. Our theoretical model for 41 K-87 Rb mixture includes thermal, loss, and density effects in a simple and conceptually clear manner. We derive several conditions in terms of the temperature, density and scattering lengths, determining the regime in which one can achieve efficient association and dissociation. This research is supported by the National Aeronautics and Space Administration.

  6. Comparison of electromagnetic and nuclear dissociation of 17Ne

    Science.gov (United States)

    Wamers, F.; Marganiec, J.; Aksouh, F.; Aksyutina, Yu.; Alvarez-Pol, H.; Aumann, T.; Beceiro-Novo, S.; Bertulani, C. A.; Boretzky, K.; Borge, M. J. G.; Chartier, M.; Chatillon, A.; Chulkov, L. V.; Cortina-Gil, D.; Emling, H.; Ershova, O.; Fraile, L. M.; Fynbo, H. O. U.; Galaviz, D.; Geissel, H.; Heil, M.; Hoffmann, D. H. H.; Hoffman, J.; Johansson, H. T.; Jonson, B.; Karagiannis, C.; Kiselev, O. A.; Kratz, J. V.; Kulessa, R.; Kurz, N.; Langer, C.; Lantz, M.; Le Bleis, T.; Lehr, C.; Lemmon, R.; Litvinov, Yu. A.; Mahata, K.; Müntz, C.; Nilsson, T.; Nociforo, C.; Ott, W.; Panin, V.; Paschalis, S.; Perea, A.; Plag, R.; Reifarth, R.; Richter, A.; Riisager, K.; Rodriguez-Tajes, C.; Rossi, D.; Savran, D.; Schrieder, G.; Simon, H.; Stroth, J.; Sümmerer, K.; Tengblad, O.; Typel, S.; Weick, H.; Wiescher, M.; Wimmer, C.

    2018-03-01

    The Borromean drip-line nucleus 17Ne has been suggested to possess a two-proton halo structure in its ground state. In the astrophysical r p -process, where the two-proton capture reaction 15O(2 p ,γ )17Ne plays an important role, the calculated reaction rate differs by several orders of magnitude between different theoretical approaches. To add to the understanding of the 17Ne structure we have studied nuclear and electromagnetic dissociation. A 500 MeV/u 17Ne beam was directed toward lead, carbon, and polyethylene targets. Oxygen isotopes in the final state were measured in coincidence with one or two protons. Different reaction branches in the dissociation of 17Ne were disentangled. The relative populations of s and d states in 16F were determined for light and heavy targets. The differential cross section for electromagnetic dissociation (EMD) shows a continuous internal energy spectrum in the three-body system 15O+2 p . The 17Ne EMD data were compared to current theoretical models. None of them, however, yields satisfactory agreement with the experimental data presented here. These new data may facilitate future development of adequate models for description of the fragmentation process.

  7. [Macroscopic liver pathology in patients with dissociated cholestasis].

    Science.gov (United States)

    Polo Sabau, J L; García Lorenzo, M D; Molina Robles, M; Carrión Román, G; San Miguel Tabernero, B; Franco López, A; Braun Saro, B

    2005-03-01

    To establish the prevalence of liver focal pathology in patients with increase of alkaline phosphatase and gamma-glutamil transpeptidase and normal bilirubin (dissociated cholestasis), and to analyze the related risk factors for such pathology. All laboratory studies of patients admitted to an Internal Medicine Department were reviewed prospectively throughout a period of 9 months. For the purpose of detecting focal liver pathology imaging liver studies (echography and/or CT) were carried out in those in which biochemical analyses showed dissociated cholestasis. A dissociated cholestasis pattern was found in 81 patients. In 13 of them (16%) focal liver pathology was demonstrated. The majority of the lesions (10 of 13) were local or metastatic malignant neoplasms. Sex, alcohol consumption, presence of diabetes mellitus, tumor or hepatobiliar disease previously known, or abnormalities in liver physical examination were not risk factors. No liver pathology was found in patients with an alkaline phosphatase level higher than double of gamma-glutamil transpeptidase level (sensitivity: 100%; negative predictive value: 100%). Diagnosis of a non-hepatic malignant neoplasm at discharge was associated to a risk 12 times bigger for the presence of liver lesions (p phosphatase alcaline: gamma-glutamil transpeptidase ratio is higher than two.

  8. DFT research of methane preliminary dissociation on aluminum catalyst

    Science.gov (United States)

    Zhang, Minhua; Yu, Yingzhe; Zhang, Yongbo

    2013-09-01

    Using the quantum chemistry calculation module based on density functional theory (DFT), the stable adsorption states of Ni4 cluster on the surface of α-Al2O3(0 0 0 1) was investigated firstly, and then the most stable adsorption configuration was selected as the representative model of supported Ni4/α-Al2O3(0 0 0 1) catalyst to investigate the catalytic performance for methane preliminary dissociation. After theoretic calculation, it was found that the methane dissociation products prefer to be adsorbed on edge sites of Ni4 cluster, the adsorption priority sequence (from large to small) for the concerned species was H > O2 > CH3 ≫ CH4 > H2. Comparing with pure Ni4 cluster without support, the chemical adsorption ability of Ni4 cluster to H2 molecule is decreased after supporting on support, which would promote the desorption of product H2, and thus increase the H2 yield. The adsorption energy of O2 molecule on Ni4/α-Al2O3(0 0 0 1) is much higher than that of other molecules such as CH4 or H2 on Ni4 cluster surface. The Osbnd O bond length on the most stable adsorption site is elongated by 0.21 Å, which would promote the activation and dissociation of O2 molecule significantly and thus might facilitate the proceeding of further reaction.

  9. A neuroanatomical dissociation for emotion induced by music.

    Science.gov (United States)

    Johnsen, Erica L; Tranel, Daniel; Lutgendorf, Susan; Adolphs, Ralph

    2009-04-01

    Does feeling an emotion require changes in autonomic responses, as William James proposed? Can feelings and autonomic responses be dissociated? Findings from cognitive neuroscience have identified brain structures that subserve feelings and autonomic response, including those induced by emotional music. In the study reported here, we explored whether feelings and autonomic responses can be dissociated by using music, a stimulus that has a strong capacity to induce emotional experiences. We tested two brain regions predicted to be differentially involved in autonomic responsivity (the ventromedial prefrontal cortex) and feeling (the right somatosensory cortex). Patients with damage to the ventromedial prefrontal cortex were impaired in their ability to generate skin-conductance responses to music, but generated normal judgments of their subjective feelings in response to music. Conversely, patients with damage to the right somatosensory cortex were impaired in their self-rated feelings in response to music, but generated normal skin-conductance responses to music. Control tasks suggested that neither impairment was due to basic defects in hearing the music or in cognitively recognizing the intended emotion of the music. The findings provide evidence for a double dissociation between feeling emotions and autonomic responses to emotions, in response to music stimuli.

  10. Electron scattering resonances and dissociative attachment in polyatomic molecules

    International Nuclear Information System (INIS)

    Olthoff, J.K.

    1985-01-01

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

  11. Axis II pathology in outpatients with dissociative identity disorder.

    Science.gov (United States)

    Dell, P F

    1998-06-01

    Forty-two outpatients with dissociative identity disorder (DID) and 16 outpatients with dissociative disorder not otherwise specified (DDNOS) were administered the Millon Clinical Multiaxial Inventory-II (MCMI-II), the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), and the Dissociative Experiences Scale (DES). DID patients manifested severe personality pathology (BR > 84) on a mean of 4.0 MCMI-II scales: avoidant (76%), self-defeating (68%), borderline (53%), and passive-aggressive (45%). DDNOS cases had severe personality pathology on fewer MCMI-II scales (mean = 1.69): avoidant (50%) and self-defeating (31%). The DID and DDNOS groups differed in their scores on the DES (means = 54.9 vs. 25.9), the PK-PTSD scale of the MMPI-2 (means = 33.6 vs. 21.7), and in the incidence of severe borderline pathology (53% vs. 6%). These data on personality pathology in DID patients are virtually identical to those of seven previous studies of personality pathology in chronic PTSD patients (i.e., avoidant, self-defeating, borderline, and passive-aggressive). Such robust convergence of findings supports the construct validity of DID as a form of posttraumatic disorder and suggests that there is a quite predictable personologic core to the clinical picture of severely traumatized individuals.

  12. Is there a dissociative process in sleepwalking and night terrors?

    Science.gov (United States)

    Hartman, D; Crisp, A; Sedgwick, P; Borrow, S

    2001-01-01

    The enduring and contentious hypothesis that sleepwalking and night terrors are symptomatic of a protective dissociative mechanism is examined. This is mobilised when intolerable impulses, feelings and memories escape, within sleep, the diminished control of mental defence mechanisms. They then erupt but in a limited motoric or affective form with restricted awareness and subsequent amnesia for the event. It has also been suggested that such processes are more likely when the patient has a history of major psychological trauma. In a group of 22 adult patients, referred to a tertiary sleep disorders service with possible sleepwalking/night terrors, diagnosis was confirmed both clinically and polysomnographically, and only six patients had a history of such trauma. More commonly these described sleepwalking/night terrors are associated with vivid dream-like experiences or behaviour related to flight from attack. Two such cases, suggestive of a dissociative process, are described in more detail.
The results of this study are presented largely on account of the negative findings. Scores on the dissociation questionnaire (DIS-Q) were normal, although generally higher in the small "trauma" subgroup. These were similar to scores characterising individuals with post-traumatic stress disorder. This "trauma" group also scored particularly highly on the anxiety, phobic, and depression scales of the Crown-Crisp experiential index. In contrast the "no trauma" group scored more specifically highly on the anxiety scale, along with major trends to high depression and hysteria scale scores. Two cases are presented which illustrate exceptional occurrence of later onset of sleepwalking/night terrors with accompanying post-traumatic symptoms during wakefulness. It is concluded that a history of major psychological trauma exists in only a minority of adult patients presenting with sleepwalking/night terror syndrome. In this subgroup trauma appears to dictate the subsequent content

  13. 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

  14. 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

  15. Abnormal Hippocampal Morphology in Dissociative Identity Disorder and Posttraumatic Stress Disorder Correlates with Childhood Trauma and Dissociative Symptoms

    Science.gov (United States)

    Chalavi, Sima; Vissia, Eline M.; Giesen, Mechteld E.; Nijenhuis, Ellert R.S.; Draijer, Nel; Cole, James H.; Dazzan, Paola; Pariante, Carmine M.; Madsen, Sarah K.; Rajagopalan, Priya; Thompson, Paul M.; Toga, Arthur W.; Veltman, Dick J.; Reinders, Antje A.T.S.

    2015-01-01

    Smaller hippocampal volume has been reported in individuals with posttraumatic stress disorder (PTSD) and dissociative identity disorder (DID), but the regional specificity of hippocampal volume reductions and the association with severity of dissociative symptoms and/or childhood traumatization are still unclear. Brain structural MRI scans were analyzed for 33 outpatients (17 with DID and 16 with PTSD only) and 28 healthy controls (HC), all matched for age, sex, and education. DID patients met criteria for PTSD (PTSD-DID). Hippocampal global and subfield volumes and shape measurements were extracted. We found that global hippocampal volume was significantly smaller in all 33 patients (left: 6.75%; right: 8.33%) compared to HC. PTSD-DID (left: 10.19%; right: 11.37%) and PTSD-only with a history of childhood traumatization (left: 7.11%; right: 7.31%) had significantly smaller global hippocampal volume relative to HC. PTSD-DID had abnormal shape and significantly smaller volume in the CA2-3, CA4-DG and (pre)subiculum compared to HC. In the patient groups, smaller global and subfield hippocampal volumes significantly correlated with higher severity of childhood traumatization and dissociative symptoms. These findings support a childhood trauma-related etiology for abnormal hippocampal morphology in both PTSD and DID and can further the understanding of neurobiological mechanisms involved in these disorders. PMID:25545784

  16. Abnormal hippocampal morphology in dissociative identity disorder and post-traumatic stress disorder correlates with childhood trauma and dissociative symptoms.

    Science.gov (United States)

    Chalavi, Sima; Vissia, Eline M; Giesen, Mechteld E; Nijenhuis, Ellert R S; Draijer, Nel; Cole, James H; Dazzan, Paola; Pariante, Carmine M; Madsen, Sarah K; Rajagopalan, Priya; Thompson, Paul M; Toga, Arthur W; Veltman, Dick J; Reinders, Antje A T S

    2015-05-01

    Smaller hippocampal volume has been reported in individuals with post-traumatic stress disorder (PTSD) and dissociative identity disorder (DID), but the regional specificity of hippocampal volume reductions and the association with severity of dissociative symptoms and/or childhood traumatization are still unclear. Brain structural magnetic resonance imaging scans were analyzed for 33 outpatients (17 with DID and 16 with PTSD only) and 28 healthy controls (HC), all matched for age, sex, and education. DID patients met criteria for PTSD (PTSD-DID). Hippocampal global and subfield volumes and shape measurements were extracted. We found that global hippocampal volume was significantly smaller in all 33 patients (left: 6.75%; right: 8.33%) compared with HC. PTSD-DID (left: 10.19%; right: 11.37%) and PTSD-only with a history of childhood traumatization (left: 7.11%; right: 7.31%) had significantly smaller global hippocampal volume relative to HC. PTSD-DID had abnormal shape and significantly smaller volume in the CA2-3, CA4-DG and (pre)subiculum compared with HC. In the patient groups, smaller global and subfield hippocampal volumes significantly correlated with higher severity of childhood traumatization and dissociative symptoms. These findings support a childhood trauma-related etiology for abnormal hippocampal morphology in both PTSD and DID and can further the understanding of neurobiological mechanisms involved in these disorders. © 2014 Wiley Periodicals, Inc.

  17. Axis-I comorbidity in female patients with dissociative identity disorder and dissociative identity disorder not otherwise specified.

    Science.gov (United States)

    Rodewald, Frauke; Wilhelm-Göling, Claudia; Emrich, Hinderk M; Reddemann, Luise; Gast, Ursula

    2011-02-01

    The aim of this study was to investigate axis-I comorbidity in patients with dissociative identity disorder (DID) and dissociative disorder not otherwise specified (DDNOS). Using the Diagnostic Interview for Psychiatric Disorders, results from patients with DID (n = 44) and DDNOS (n = 22) were compared with those of patients with posttraumatic stress disorder (PTSD) (n = 13), other anxiety disorders (n = 14), depression (n = 17), and nonclinical controls (n = 30). No comorbid disorders were found in nonclinical controls. The average number of comorbid disorders in patients with depression or anxiety was 0 to 2. Patients with dissociative disorders averagely suffered from 5 comorbid disorders. The most prevalent comorbidity in DDNOS and DID was PTSD. Comorbidity profiles of patients with DID and DDNOS were very similar to those in PTSD (high prevalence of anxiety, somatoform disorders, and depression), but differed significantly from those of patients with depression and anxiety disorders. These findings confirm the hypothesis that PTSD, DID, and DDNOS are phenomenologically related syndromes that should be summarized within a new diagnostic category.

  18. 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

  19. [Verification of the double dissociation model of shyness using the implicit association test].

    Science.gov (United States)

    Fujii, Tsutomu; Aikawa, Atsushi

    2013-12-01

    The "double dissociation model" of shyness proposed by Asendorpf, Banse, and Mtücke (2002) was demonstrated in Japan by Aikawa and Fujii (2011). However, the generalizability of the double dissociation model of shyness was uncertain. The present study examined whether the results reported in Aikawa and Fujii (2011) would be replicated. In Study 1, college students (n = 91) completed explicit self-ratings of shyness and other personality scales. In Study 2, forty-eight participants completed IAT (Implicit Association Test) for shyness, and their friends (n = 141) rated those participants on various personality scales. The results revealed that only the explicit self-concept ratings predicted other-rated low praise-seeking behavior, sociable behavior and high rejection-avoidance behavior (controlled shy behavior). Only the implicit self-concept measured by the shyness IAT predicted other-rated high interpersonal tension (spontaneous shy behavior). The results of this study are similar to the findings of the previous research, which supports generalizability of the double dissociation model of shyness.

  20. 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.

  1. Adsorption and dissociation of H2O on Al(1 1 1) surface by density functional theory calculation

    International Nuclear Information System (INIS)

    Guo, F.Y.; Long, C.G.; Zhang, J.; Zhang, Z.; Liu, C.H.; Yu, K.

    2015-01-01

    Highlights: • O 2 on Al(1 1 1) surface can spontaneously dissociate, but H 2 O can not. • H 2 O, OH and H on top sites are favorable on Al(1 1 1) surface. • O on the hollow (fcc) site is preferred. • O which plays a key role in the dissociate reaction of H 2 O. - Abstract: Using the first-principles calculations method based on the density functional theory, we systematically study the adsorption behavior of a single molecular H 2 O on a clean and a pre-adsorbed O atom Al(1 1 1) surface, and also its corresponding dissociation reactions. The equilibrium configuration on top, bridge, and hollow (fcc and hcp) site were determined by relaxation of the system relaxation. The adsorptions of H 2 O, OH and H on top sites are favorable on the Al(1 1 1) surface, while that of O on the hollow (fcc) site is preferred. The results show that the hydrogen atom dissociating from H 2 O needs a 248.32 kJ/mol of energy on clean Al(1 1 1) surface, while the dissociating energy decreases to 128.53 kJ/mol with the aid of the O absorption. On the other hand, these phenomena indicate that the dehydrogenated reaction energy barrier of the pre-adsorbed O on metal surface is lower than that of on a clean one, because O can promote the dehydrogenation of H 2 O

  2. PTSD, emotion dysregulation, and dissociative symptoms in a highly traumatized sample

    Science.gov (United States)

    Powers, Abigail; Cross, Dorthie; Fani, Negar; Bradley, Bekh

    2015-01-01

    Exposure to multiple traumas has been shown to result in many negative mental health outcomes, including posttraumatic stress disorder (PTSD). Dissociation, which involves disruptions in memory, identity, and perceptions, may be a component of PTSD, particularly among individuals who have experienced childhood trauma. Emotion regulation difficulties are also strongly associated with childhood trauma and emotion dysregulation may be a particularly important factor to consider in the development and maintenance of dissociative symptoms. The goal of the present study was to determine whether emotion dysregulation mediated the relationship between PTSD symptoms and dissociation in a sample of 154 (80% female, 97% African-American) adults recruited from a public, urban hospital. PTSD was measured using the Clinician Administered PTSD Scale, emotion dysregulation was measured using the Difficulties in Emotion Regulation Scale, and dissociation was measured using the Multiscale Dissociation Inventory. A linear regression analysis showed that both PTSD and emotion dysregulation were statistically significant predictors of dissociation even after controlling for trauma exposure. Alexithymia and an inability to use emotion regulation strategies in particular were predictive of dissociation above and beyond other predictor variables. Using bootstrapping techniques, we found that overall emotion dyregulation partially mediated the effect of PTSD symptoms on dissociative symptoms. Our results suggest that emotion dysregulation may be important in understanding the relation between PTSD and dissociative symptoms. Treatment approaches may consider a focus on training in emotional understanding and the development of adaptive regulation strategies as a way to address dissociative symptoms in PTSD patients. PMID:25573648

  3. 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.

  4. Childhood trauma and dissociation in first-episode psychosis, chronic schizophrenia and community controls.

    Science.gov (United States)

    Braehler, Christine; Valiquette, Luc; Holowka, Darren; Malla, Ashok K; Joober, Ridha; Ciampi, Antonio; Pawliuk, Nicole; King, Suzanne

    2013-11-30

    Increasing evidence supports the role of childhood trauma in the etiology of psychosis but underlying mechanisms are poorly understood. Early maltreatment has been linked to dissociative symptoms in psychosis patients. We explored associations between childhood trauma (Childhood Trauma Questionnaire) and dissociation (Dissociative Experiences Scale) in first-episode psychotic patients (n=62), chronic psychotic patients (n=43), and non-psychotic community controls (n=66). Multivariate analyses of covariance were used to test associations between childhood trauma and dissociation by group while controlling for sex. Chronic patients reported the highest level of dissociation. More severe childhood trauma was associated with greater dissociative symptoms in all groups although most strongly in chronic patients. Emotional abuse showed the strongest associations with dissociation, with these being strongest for chronic patients, followed by first-episode patients--and least for controls. Men showed a stronger association between physical neglect and dissociation than women, irrespective of group. There were no significant group by sex interactions. Our findings replicate the strong association between childhood trauma and dissociative symptoms in chronic and first-episode psychotic patients relative to non-psychotic control subjects. We also demonstrate the salience of emotional abuse in explaining variance in dissociation, especially in chronic patients. © 2013 Elsevier Ireland Ltd. All rights reserved.

  5. Attachment insecurity as a mediator of the relationship between childhood trauma and adult dissociation.

    Science.gov (United States)

    Kong, Seong Sook; Kang, Dae Ryong; Oh, Min Jung; Kim, Nam Hee

    2018-01-01

    This study aimed to investigate whether attachment insecurity mediates the relationship between childhood trauma and adult dissociation, specifically with regard to individual forms of childhood maltreatment. Psychiatric outpatients who visited a specialized trauma clinic (n = 115) participated in the study. Data were collected via the Childhood Trauma Questionnaire, Revised Adult Attachment Scale, and Dissociative Experience Scale. Structural equation modeling and path analysis were performed to analyze the mediating effects of attachment insecurity on the relationship between childhood trauma and adult dissociation. Greater childhood trauma was associated with higher dissociation, and the relationship between them was fully mediated by attachment anxiety. In path analysis of trauma subtypes, the effects of emotional abuse, physical abuse, and physical neglect as a child on adult dissociation were found to be fully mediated by attachment anxiety. The effect of sexual abuse on dissociation was mediated by a synergistic effect from both attachment anxiety and attachment avoidance. Regarding emotional neglect, a countervailing interaction was discovered between the direct and indirect effects thereof on dissociation; the indirect effect of emotional neglect on dissociation was partially mediated by attachment insecurity. Specific aspects of attachment insecurity may help explain the relationships between individual forms of childhood trauma and adult dissociative symptoms. Tailored treatments based on affected areas of attachment insecurity may improve outcomes among patients with dissociative symptoms and a history of childhood trauma.

  6. 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.

  7. Temperament and character traits in patients with conversion disorder and their relations with dissociation.

    Science.gov (United States)

    Sarisoy, Gökhan; Kaçar, Ö Mer Faruk; Öztürk, Arif; Yilman, Tuba; Mor, Sema; Özturan, Deniz Deniz; Yazici, Neslihan; Gümüş, Kübra

    2015-12-01

    The purpose of this study was to investigate temperament and character traits in patients with conversion disorder and the relation of these traits with dissociative symptoms. Sixty patients (60) diagnosed with conversion disorder according to DSM-IV-TR and 60 healthy volunteers were included in the study. All participants' temperament and character traits were determined using Cloninger's Temperament and Character Inventory (TCI). Patients with conversion disorder were divided into two subgroups using the Dissociative Experiences Scale (DES), dissociative (n=30, 50%) and non-dissociative (n=30, 50%). The two conversion disorder subgroups were compared with the control group in terms of temperament and character traits. Correlation analysis was also performed between TCI and DES scores in the entire conversion group. Novelty seeking (NS) scores were lower in both the dissociative and non-dissociative groups compared to the control group. Harm avoidance (HA) scores were higher in the dissociative group than in the control group. Reward dependence (RD) scores were lower in the dissociative group than in the non-dissociative and control group. Self-directedness (SD) scores were lower in the dissociative group than in the control group. Self-transcendence (ST) scores were higher in the dissociative group than in the non-dissociative group. DES scores were negatively correlated with RD and SD scores in the entire conversion group and positively correlated with ST scores. Low NS temperament traits may be associated with conversion disorder. High HA and low RD temperament traits and low SD and high ST character traits may be associated with pathological dissociation in patients with conversion disorder.

  8. Development and control of epileptiform bursting in dissociated cortical cultures

    Science.gov (United States)

    Wagenaar, Daniel A.

    Cortical cells in dissociated culture form densely interconnected networks. Within days after plating, neurons become electrically active, and soon after start to synchronize their activity into culture-wide bursts. By growing cultures on multi-electrode arrays (Petri dishes with a grid of substrate-embedded electrodes), their electrical activity can be recorded non-invasively.I developed software, MEABench, for online visualization and analysis of multi-electrode data, and used it to follow the development of cultures obtained from (E18) embryonic rats. Globally synchronized bursting was observed in all but the most sparsely plated cultures. A remarkable range of bursting behaviors was observed, even in cultures with identical plating parameters. Activity patterns varied widely in terms of the frequency, intensity, duration, and degree of temporal clustering of bursts. During the 2nd week in vitro, bursts in many dense cultures clustered into well-defined trains, separated by long periods without bursts. The number of bursts within these 'superbursts' and their spatiotemporal structure were found to be stable for hours or days.Cortical cultures on multi-electrode arrays are ideal for studying two-way communication between biological systems and computers. I designed and built hardware to deliver electrical stimuli in arbitrary patterns, developed software to remove stimulation artifacts from recordings, and studied the efficacy of several voltage-defined and current-defined stimulus waveforms. MEABench can control the stimulator in real-time. Thus, stimuli can be made dependent on a culture's activity with only 15 ms lag-time.We hypothesized that synchronized bursting can dominate activity patterns, because lack of external input puts cultures in a hypersensitive state. Indeed, by feeding cultures a steady stream of stimuli, distributed over many electrodes, bursting could be prevented completely. The number of electrodes required for successful burst control

  9. 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.

  10. Retrospective review of lumbosacral dissociations in blast injuries.

    Science.gov (United States)

    Helgeson, Melvin D; Lehman, Ronald A; Cooper, Patrick; Frisch, Michael; Andersen, Romney C; Bellabarba, Carlo

    2011-04-01

    Retrospective review of medical records and radiographs. We assessed the clinical outcomes of lumbosacral dissociation (LSD) after traumatic, combat-related injuries, and to review our management of these distinct injuries and report our preliminary follow-up. LSD injuries are an anatomic separation of the pelvis from the spinal column, and are the result of high-energy trauma. A relative increase in these injuries has been seen in young healthy combat casualties subjected to high-energy blast trauma. We performed a retrospective review of inpatient/outpatient medical records and radiographs for all patients treated at our institution with combat-related lumbosacral dissociations. Twenty-three patients met inclusion criteria of combat-related lumbosacral dissociations with one-year follow-up. Patients were treated as follows: no fixation (9), sacroiliac screw fixation (8), posterior spinal fusion (5) and sacral plate (1). All patients with radiographic evidence of a zone III sacral fracture, in addition to associated lumbar fractures indicating loss of the iliolumbar ligamentous complex integrity were included. In 15 patients, the sacral fracture were an H or U type zone III fracture, whereas in the remaining nine, the sacral fracture was severely comminuted and unable to classify (six open fractures). There was no difference in visual analog scale (VAS) between treatment modalities. Two open injuries had residual infections. One patient treated with an L4-ilium posterior spinal fusion with instrumentation required instrumentation removal for infection. At a mean follow-up of 1.71 years (range, 1-4.5), 11 patients (48%) still reported residual pain and the mean VAS at latest follow-up was 1.7 (range, 0-7). Operative stabilization promoted healing and earlier mobilization, but carries a high-postoperative risk of infection. Nonoperative management should be considered in patients whose comorbidities prevent safe stabilization.

  11. Dissociable brain mechanisms for processing social exclusion and rule violation.

    Science.gov (United States)

    Bolling, Danielle Z; Pitskel, Naomi B; Deen, Ben; Crowley, Michael J; McPartland, James C; Mayes, Linda C; Pelphrey, Kevin A

    2011-02-01

    Social exclusion inherently involves an element of expectancy violation, in that we expect other people to follow the unwritten rule to include us in social interactions. In this functional magnetic resonance imaging (fMRI) study, we employed a unique modification of an interactive virtual ball-tossing game called "Cyberball" (Williams et al., 2000) and a novel paradigm called "Cybershape," in which rules are broken in the absence of social exclusion, to dissociate brain regions that process social exclusion from rule violations more generally. Our Cyberball game employed an alternating block design and removed evoked responses to events when the participant was throwing the ball in inclusion to make this condition comparable to exclusion, where participants did not throw. With these modifications, we replicated prior findings of ventral anterior cingulate cortex (vACC), insula, and posterior cingulate cortex activity evoked by social exclusion relative to inclusion. We also identified exclusion-evoked activity in the hippocampi, left ventrolateral prefrontal cortex, and left middle temporal gyrus. Comparing social exclusion and rule violation revealed a functional dissociation in the active neural systems as well as differential functional connectivity with vACC. Some overlap was observed in regions differentially modulated by social exclusion and rule violation, including the vACC and lateral parietal cortex. These overlapping brain regions showed different activation during social exclusion compared to rule violation, each relative to fair play. Comparing activation patterns to social exclusion and rule violation allowed for the dissociation of brain regions involved in the experience of exclusion versus expectancy violation. Copyright © 2010 Elsevier Inc. All rights reserved.

  12. Measurement of Dissociation Rate of Biomolecular Complexes Using Capillary Electrophoresis

    Science.gov (United States)

    Yang, Peilin; Mao, Yingwei; Lee, Angel W.-M; Kennedy, Robert T.

    2009-01-01

    Fluorescence anisotropy (FA), non-equilibrium capillary electrophoresis of equilibrium mixtures (NECEEM) and high-speed capillary electrophoresis (CE) were evaluated for measuring dissociation kinetics of peptide-protein binding systems. Fyn-SH3-SH2, a protein construct consisting of the Src homology 2 (SH2) and SH3 domain of the protein Fyn, and a fluorescein-labeled phosphopeptide were used as a model system. All three methods gave comparable half-life of ~53 s for Fyn-SH3-SH2:peptide complex. Achieving satisfactory results by NECEEM required columns over 30 cm long. When using Fyn-SH2-SH3 tagged with glutathione S-transferase (GST) as the binding protein, both FA and NECEEM assays gave evidence of two complexes forming with the peptide, yet neither method allowed accurate measurement of dissociation rates for both complexes because of a lack of resolution. High-speed CE, with a 7 s separation time, enabled separation of both complexes and allowed determination of dissociation rate of both complexes independently. The two complexes had half-lives of 22.0 ± 2.7 and 58.8 ± 6.1 s respectively. Concentration studies revealed that the GST-Fyn-SH3-SH2 protein formed a dimer so that complexes had binding ratios of 2:1 (protein-to-peptide ratio) and 2:2. Our results demonstrate that while all methods are suitable for 1:1 binding systems, high-speed CE is unique in allowing multiple complexes to be resolved simultaneously. This property allows determination of binding kinetics of complicated systems and makes the technique useful for discovering novel affinity interactions. PMID:19148904

  13. Dissociative sticking of CH4 on Ru(0001)

    DEFF Research Database (Denmark)

    Nielsen, Jane Hvolbæk; Holmblad, Peter Mikal; Chorkendorff, Ib

    1999-01-01

    In this study the CH4 dissociation probability on Ru(0001) is found for various translational and vibrational energies. The absolute sticking values are determined from King and Wells experiments and carbon uptake curves. The carbon amount is determined from the recombination signal of carbon...... with oxygen obtained after the beam exposure when heating in an oxygen atmosphere. The measured sticking coefficient of CH4 is strongly enhanced both by increasing the translational and the vibrational energy of the CH4 molecule. A model is applied to the data and an estimate of the thermal activation energy...

  14. Effects of sleep deprivation on dissociated components of executive functioning.

    Science.gov (United States)

    Tucker, Adrienne M; Whitney, Paul; Belenky, Gregory; Hinson, John M; Van Dongen, Hans P A

    2010-01-01

    We studied the effects of sleep deprivation on executive functions using a task battery which included a modified Sternberg task, a probed recall task, and a phonemic verbal fluency task. These tasks were selected because they allow dissociation of some important executive processes from non-executive components of cognition. Subjects were randomized to a total sleep deprivation condition or a control condition. Performance on the executive functions task battery was assessed at baseline, after 51 h of total sleep deprivation (or no sleep deprivation in the control group), and following 2 nights of recovery sleep, at fixed time of day (11:00). Performance was also measured repeatedly throughout the experiment on a control task battery, for which the effects of total sleep deprivation had been documented in previously published studies. Six consecutive days and nights in a controlled laboratory environment with continuous behavioral monitoring. Twenty-three healthy adults (age range 22-38 y; 11 women). Twelve subjects were randomized to the sleep deprivation condition; the others were controls. Performance on the control task battery was considerably degraded during sleep deprivation. Overall performance on the modified Sternberg task also showed impairment during sleep deprivation, as compared to baseline and recovery and compared to controls. However, two dissociated components of executive functioning on this task--working memory scanning efficiency and resistance to proactive interference--were maintained at levels equivalent to baseline. On the probed recall task, resistance to proactive interference was also preserved. Executive aspects of performance on the phonemic verbal fluency task showed improvement during sleep deprivation, as did overall performance on this task. Sleep deprivation affected distinct components of cognitive processing differentially. Dissociated non-executive components of cognition in executive functions tasks were degraded by sleep

  15. [Factitious disorders in dermatology: Value of the dissociative state concept].

    Science.gov (United States)

    Fekih-Romdhane, F; Homri, W; Labbane, R

    2016-03-01

    Factitious disorders in dermatology consist of intentionally self-inflicted skin lesions that vary in morphology and distribution and occur on surfaces readily accessible to the patient's hands. They tend to be a chronic condition that waxes and wanes according to the circumstances of the patient's life. Patient management poses a particular challenge to the clinician and the prognosis is considered poor. The aetiopathogenesis of factitious disorders in dermatology is not completely understood. We present a case in which we suggested the occurrence of factitious behaviour during a dissociative state, and we briefly describe our diagnostic and therapeutic approach. A 48-year-old unemployed woman was referred to our department of psychiatry by her dermatologist for suspected factitious disorder. The patient was diagnosed with diabetes mellitus type 1 and had been hospitalized repeatedly for confirmed diabetic ketoacidosis. The onset of the disease was related to marital discord with her spouse. Numerous skin lesions had appeared on her face, arms, legs, neck and back. These lesions resulted in multiple hospital admissions and in amputation of her left leg. The condition had worsened considerably after her separation from her husband. During the initial conversation, the patient was unable to provide a clear history of the disease. She denied any knowledge of the circumstances in which these skin lesions appeared, and she did not admit self-infliction. Her mood was depressed and her speech was slow. We suspected that our patient was herself causing her skin lesions while in a dissociative state. Several arguments militate in favour of our hypothesis, particularly her history of childhood maltreatment and the association of traumatic life events with simultaneous deterioration of the skin. The explanation of the dissociative mechanism helped us to strengthen the therapeutic relationship. Within a few days, we noted a slow regression of the lesions, but the patient was

  16. Microstructural and analytical analysis of plasma dissociated zircon

    International Nuclear Information System (INIS)

    Minnaar, E G; Neethling, J H; Lee, M E; Snyders, E

    2012-01-01

    The investigation of the microstructure and distribution of impurities was carried out on plasma dissociated zircon (PDZ). The morphology of the PDZ and crystalline nature of the zirconia was determined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) while energy dispersive X-ray spectrometry (EDS) provided compositional information. The SEM and TEM results indicate that the morphology and crystalline nature of the zirconia varies as a result of the existence of a thermal gradient. The EDS results show that the majority of the impurities segregates to the silica phase of the PDZ.

  17. A streptavidin variant with slower biotin dissociation and increased mechanostability

    Science.gov (United States)

    Chivers, Claire E.; Crozat, Estelle; Chu, Calvin; Moy, Vincent T.; Sherratt, David J.; Howarth, Mark

    2010-01-01

    Streptavidin binds biotin-conjugates with exceptional stability, but dissociation does occur and can be limiting in imaging, DNA amplification, and nanotechnology. We identified a mutant streptavidin, which we call traptavidin, showing ~10-fold slower biotin off-rate, increased mechanical strength, and improved thermostability; this resilience should find diverse applications. We show that the motor protein FtsK could strip proteins from DNA, rapidly displacing streptavidin from biotinylated DNA; traptavidin resisted displacement and thus indicated the force generated by FtsK translocation. PMID:20383133

  18. Is there a dissociative process in sleepwalking and night terrors?

    Science.gov (United States)

    Hartman, D; Crisp, A H; Sedgwick, P; Borrow, S

    2001-04-01

    The enduring and contentious hypothesis that sleepwalking and night terrors are symptomatic of a protective dissociative mechanism is examined. This is mobilised when intolerable impulses, feelings and memories escape, within sleep, the diminished control of mental defence mechanisms. They then erupt but in a limited motoric or affective form with restricted awareness and subsequent amnesia for the event. It has also been suggested that such processes are more likely when the patient has a history of major psychological trauma. In a group of 22 adult patients, referred to a tertiary sleep disorders service with possible sleepwalking/night terrors, diagnosis was confirmed both clinically and polysomnographically, and only six patients had a history of such trauma. More commonly these described sleepwalking/night terrors are associated with vivid dream-like experiences or behaviour related to flight from attack. Two such cases, suggestive of a dissociative process, are described in more detail. The results of this study are presented largely on account of the negative findings. Scores on the dissociation questionnaire (DIS-Q) were normal, although generally higher in the small "trauma" subgroup. These were similar to scores characterising individuals with post-traumatic stress disorder. This "trauma" group also scored particularly highly on the anxiety, phobic, and depression scales of the Crown-Crisp experiential index. In contrast the "no trauma" group scored more specifically highly on the anxiety scale, along with major trends to high depression and hysteria scale scores. Two cases are presented which illustrate exceptional occurrence of later onset of sleepwalking/night terrors with accompanying post-traumatic symptoms during wakefulness. It is concluded that a history of major psychological trauma exists in only a minority of adult patients presenting with sleepwalking/night terror syndrome. In this subgroup trauma appears to dictate the subsequent content of

  19. The effect of the two tailored femtosecond laser pulses in the enhancement of methane dissociation

    International Nuclear Information System (INIS)

    Sadighi-Bonabi, R.; Dehghani, Z.; Irani, E.

    2010-01-01

    Complete text of publication follows. Based on the gradient optimization method a useful approach for dissociation of the methane molecule is introduced. This analytical model produces an optimized two tailored rectangular laser pulses which dissociates the molecular ion CH 4 + with maximum probability of 1. In this approach the field assisted dissociation is used by a semi-classical view. It is assumed that only the selective dissociative bond is in direction of the laser electric field are effective. Saturation is found for dissociation of the mentioned molecular bond, where the first pulse should have higher intensity than the second pulse. In addition to that, the sensitivity of the dissociation probability to the initial bond length and the control of the desired product channel by variation of the laser intensity and its duration of laser field is presented.

  20. The relationship of problematic internet use with dissociation among South Korean internet users.

    Science.gov (United States)

    Lee, Tae Kyung; Roh, Sungwon; Han, Joo Hyun; Park, Se Jin; Soh, Min A; Han, Doug Hyun; Shaffer, Howard J

    2016-07-30

    This study examined patterns of problematic internet use (PIU) among South Korean internet users to investigate the association between PIU and dissociative experiences. Five hundred and eight participants between 20 and 49 years old were recruited through an online panel survey. Using logistic regression analysis with PIU as the dependent variable, we observed that the participants with PIU were more likely to have alcohol-related behaviors or problems, higher levels of perceived stress, and dissociative experiences. Participants' scores on the Korean version of the Dissociative Experiences Scale were positively correlated with the severity of PIU. Individuals with PIU and dissociation had more severe PIU and more severe mental-health problems than those with PIU but without dissociation. These findings suggest that treatment programs for persons with PIU should focus on helping them tolerate negative affect and increase their level of awareness to prevent the occurrence of dissociative experiences. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. Secondary traumatic stress, dissociative and somatization symptoms in spouses of veterans with PTSD in Zahedan, Iran.

    Science.gov (United States)

    Kianpoor, Mohsen; Rahmanian, Parisa; Mojahed, Azizollah; Amouchie, Ramin

    2017-04-01

    Secondary traumatic stress is a disorder which occurs in spouses and people with close relation to someone with posttraumatic stress disorder. Like PTSD, it seems that STS also occurs with other psychiatric problems like somatization and dissociation. This study aimed to determine the relationship between STS and somatization and dissociation symptoms. This cross-sectional study was done in 2015 and lasted for one year. Self-report questionnaires assessing secondary traumatic stress symptoms, dissociation symptoms and somatization symptoms were distributed among spouses of veterans with PTSD in Zahedan, Iran. The relationship between STS symptoms and somatization symptoms and also between STS symptoms and dissociation symptoms were determined by Pearson correlation test. SPSS version 23 was used for data analysis. Occurrence of secondary traumatic stress symptoms were correlated with dissociation symptoms and also with somatization symptoms. As the rate of secondary traumatic stress rose, the rate of somatization and dissociation symptoms in spouses of veterans increased.

  2. Multiphoton dissociation of CF3I clusters by IR laser radiation

    International Nuclear Information System (INIS)

    Lokhman, V. N.; Ogurok, D. D.; Ryabov, E. A.

    2009-01-01

    The results of investigation of dissociation of (CF 3 I) n clusters upon resonant excitation of vibrations of CF 3 I molecules by pulsed CO 2 laser radiation are reported. The kinetics of dissociation of such clusters is studied and the dissociation yield is measured. It is shown that its value is completely controlled by fluence Φ IR of transmitted IR radiation energy and its time dependence is exponential. The results of measurements show that the dissociation lifetime of clusters is shorter than 10 -8 s. The velocity and translational temperature of free CF 3 I molecules formed during dissociation of clusters are measured, as well as the dependence of these parameters on Φ IR . It is concluded that, under these conditions of IR excitations, the dissociation of (CF 3 I) n clusters can be treated as consecutive evaporation of molecules

  3. An Examination of Dissociative Symptoms As They Relate To Indigenous Filipino Concepts

    Directory of Open Access Journals (Sweden)

    Heather J. Davediuk Gingrich

    2006-12-01

    Full Text Available In one phase of a larger study entitled Dissociation in a student sample in the Philippines (Gingrich, 2004, interviewees were asked to give their opinions about various scenarios involving dissociative symptoms, including whether they would regard specific dissociative experiences as normal or pathological.These college students were also requested to suggest indigenous terms for dissociative symptoms in Filipino languages. In order to provide a context for a discussion of these qualitative research findings, dissociation is defined, andplaced in its historical and cross-cultural context. A summary of how dissociative symptoms have generally been viewed within the Philippines is also included. The methodology used in the larger study is briefly outlined, while the procedures used to collect the data most relevant to the purposes ofthis article are more thoroughly described. Relevance of the findings for the social sciences is discussed, and recommendations for further research made.

  4. Dissociative identity disorder among adolescents: prevalence in a university psychiatric outpatient unit.

    Science.gov (United States)

    Sar, Vedat; Onder, Canan; Kilincaslan, Ayse; Zoroglu, Süleyman S; Alyanak, Behiye

    2014-01-01

    The aim of this study was to determine the prevalence of dissociative identity disorder (DID) and other dissociative disorders among adolescent psychiatric outpatients. A total of 116 consecutive outpatients between 11 and 17 years of age who were admitted to the child and adolescent psychiatry clinic of a university hospital for the 1st time were evaluated using the Adolescent Dissociative Experiences Scale, adolescent version of the Child Symptom Inventory-4, Childhood Trauma Questionnaire, and McMaster Family Assessment Device. All patients were invited for an interview with the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D) administered by 2 senior psychiatrists in a blind fashion. There was excellent interrater reliability between the 2 clinicians on SCID-D diagnoses and scores. Among 73 participants, 33 (45.2%) had a dissociative disorder: 12 (16.4%) had DID, and 21 (28.8%) had dissociative disorder not otherwise specified. There was no difference in gender distribution, childhood trauma, or family dysfunction scores between the dissociative and nondissociative groups. Childhood emotional abuse and family dysfunction correlated with self-reported dissociation. Of the dissociative adolescents, 93.9% had an additional psychiatric disorder. Among them, only separation anxiety disorder was significantly more prevalent than in controls. Although originally designed for adults, the SCID-D is promising for diagnosing dissociative disorders in adolescents, its modest congruence with self-rated dissociation and lack of relationship between diagnosis and childhood trauma and family dysfunction suggest that the prevalence rates obtained with this instrument originally designed for adults must be replicated. The introduction of diagnostic criteria for adolescent DID in revised versions of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, would refine the assessment of dissociative disorders in this age group.

  5. Production of dissociated hydrogen gas by electro-magnetically driven shock

    International Nuclear Information System (INIS)

    Kondo, Kotaro; Moriyama, Takao; Hasegawa, Jun; Horioka, Kazuhiko; Oguri, Yoshiyuki

    2013-01-01

    Evaluation of ion stopping power which has a dependence on target temperature and density is an essential issue for heavy-ion-driven high energy density experiment. We focus on experimentally unknown dissociated hydrogen atoms as target for stopping power measurement. The precise measurement of shock wave velocity is required because the dissociated gas is produced by electro-magnetically driven shock. For beam-dissociated hydrogen gas interaction experiment, shock velocity measurement using laser refraction is proposed. (author)

  6. Collisionless dissociation and isotopic enrichment of SF6 using high-powered CO2 laser radiation

    Science.gov (United States)

    Gower, M. C.; Billman, K. W.

    1977-01-01

    Dissociation of S-32F6 and the resultant isotopic enrichment of S-34F6 using high-powered CO2 laser radiation has been studied with higher experimental sensitivity than previously reported. Enrichment factors have been measured as a function of laser pulse number, wavelength, energy and time duration. A geometry independent dissociation cross section is introduced and measured values are presented. Threshold energy densities, below which no dissociation was observed, were also determined.

  7. Inter-identity autobiographical amnesia in patients with dissociative identity disorder

    OpenAIRE

    Huntjens, Rafaele JC; Verschuere, Bruno; McNally, Richard 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 of dissociative amnesia. The aim of the current study was to objectively assess transfer of autobiographical information between identities in a larger sample of DID patients. Methods: Using a c...

  8. Modeling deoxyribose radicals by neutralization-reionization mass spectrometry. Part 2. Preparation, dissociations, and energetics of 3-hydroxyoxolan-3-yl radical and cation.

    Science.gov (United States)

    Vivekananda, Shetty; Sadílek, Martin; Chen, Xiaohong; Adams, Luke E; Turecek, Frantisek

    2004-07-01

    The title radical (1) is generated in the gas-phase by collisional neutralization of carbonyl-protonated oxolan-3-one. A 1.5% fraction of 1 does not dissociate and is detected following reionization as survivor ions. The major dissociation of 1 (approximately 56%) occurs as loss of the hydroxyl H atom forming oxolan-3-one (2). The competing ring cleavages by O[bond]C-2 and C-4[bond]C-5 bond dissociations combined account for approximately 42% of dissociation and result in the formation of formaldehyde and 2-hydroxyallyl radical. Additional ring-cleavage dissociations of 1 resulting in the formation of C(2)H(3)O and C(2)H(4)O cannot be explained as occurring competitively on the doublet ground (X) electronic state of 1, but are energetically accessible from the A and higher electronic states accessed by vertical electron transfer. Exothermic protonation of 2 also produces 3-oxo-(1H)-oxolanium cation (3(+)) which upon collisional neutralization gives hypervalent 3-oxo-(1H)-oxolanium radical (3). The latter dissociates spontaneously by ring opening and expulsion of hydroxy radical. Experiment and calculations suggest that carbohydrate radicals incorporating the 3-hydroxyoxolan-3-yl motif will prefer ring-cleavage dissociations at low internal energies or upon photoexcitation by absorbing light at approximately 590 and approximately 400 nm.

  9. Dissociation, shame, complex PTSD, child maltreatment and intimate relationship self-concept in dissociative disorder, chronic PTSD and mixed psychiatric groups.

    Science.gov (United States)

    Dorahy, Martin J; Middleton, Warwick; Seager, Lenaire; McGurrin, Patrick; Williams, Mary; Chambers, Ron

    2015-02-01

    Whilst a growing body of research has examined dissociation and other psychiatric symptoms in severe dissociative disorders (DDs), there has been no systematic examination of shame and sense of self in relationships in DDs. Chronic child abuse often associated with severe DDs, like dissociative identity disorder, is likely to heighten shame and relationship concerns. This study investigated complex posttraumatic stress disorder (PTSD), borderline and Schneiderian symptoms, dissociation, shame, child abuse, and various markers of self in relationships (e.g., relationship esteem, relationship depression, fear of relationships). Participants were assessed via clinical interview with psychometrically sound questionnaires. They fell into three diagnostic groups, dissociative disorder (n=39; primarily dissociative identity disorder), chronic PTSD (Chr-PTSD; n=13) or mixed psychiatric presentations (MP; n=21; primarily mood and anxiety disorders). All participants had a history of child abuse and/or neglect, and the groups did not differ on age and gender. The DD group was higher on nearly all measured variables than the MP group, and had more severe dissociative, borderline and Schneiderian symptoms than the Chr-PTSD sample. Shame and complex PTSD symptoms fell marginally short of predicting reductions in relationship esteem, pathological dissociative symptoms predicted increased relationship depression, and complex PTSD symptoms predicted fear of relationships. The representativeness of the samples was unknown. Severe psychiatric symptoms differentiate DDs from chronic PTSD, while dissociation and shame have a meaningful impact on specific markers of relationship functioning in psychiatric patients with a history of child abuse and neglect. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Oxygen vacancies as active sites for water dissociation on rutile TiO2(110)

    DEFF Research Database (Denmark)

    Schaub, R.; Thostrup, P.; Lopez, Nuria

    2001-01-01

    to dissociate H2O through the transfer of one proton to a nearby oxygen atom, forming two hydroxyl groups for every vacancy. The amount of water dissociation is limited by the density of oxygen vacancies present on the clean surface exclusively. The dissociation process sets in as soon as molecular water......Through an interplay between scanning tunneling microscopy experiments and density functional theory calculations, we determine unambiguously the active surface site responsible for the dissociation of water molecules adsorbed on rutile TiO2(110). Oxygen vacancies in the surface layer are shown...

  11. Imagining the impossible before breakfast: The relation between creativity, dissociation, and sleep

    Directory of Open Access Journals (Sweden)

    Dalena eVan Heugten - Van Der Kloet

    2015-03-01

    Full Text Available Dissociative symptoms have been related to higher Rapid Eye Movement (REM sleep density, a sleep phase during which hyperassociativity may occur. This may enhance artistic creativity during the day. To test this hypothesis, we conducted a creative photo contest to explore the relation between dissociation, sleep, and creativity. During the contest, participants (N=72 took one photo per day for five consecutive days, based on specific daily themes (consisting of single words and the instruction to take as creative a photo as possible each day. Furthermore, they completed daily measures of state dissociation and a short sleep diary. The photos and their captions were ranked by two professional photographers and two clinical psychologists based on creativity, originality, bizarreness, and quality. We expected that dissociative people would rank higher in the contest compared with low-dissociative participants, and that the most original photos would be taken on days when the participants scored highest on acute dissociation.We found that acute dissociation predicted a higher ranking on creativity. Poorer sleep quality and fewer hours of sleep predicted more bizarreness in the photos and captions. None of the trait measures could predict creativity.In sum, acute dissociation related to enhanced creativity. These findings contribute to our understanding of dissociative symptomatology.

  12. Type of presentation of dissociative disorder and frequency of co-morbid depressive disorder.

    Science.gov (United States)

    Alvi, Tabassum; Minhas, Fareed Aslam

    2009-02-01

    To determine the frequency distribution of various types of dissociative disorders, along with existing co-morbid depression and its level of severity in patients with dissociative disorder. Observational, cross-sectional study. The Institute of Psychiatry, Rawalpindi General Hospital from October 2004 to March 2005. Fifty consecutive patients were included in the study through non-probable purposive sampling technique. Encounter form included socio-demographic profile and brief psychiatric history. ICD 10 diagnostic criteria for research were administered for determining the presentation of dissociative disorder. Present state examination was applied to make diagnosis of depressive disorder in the studied patients. Descriptive statistics for frequency analysis of sociodemographic variables, type of presentation of dissociative disorder and the frequency of depressive disorder in patients of dissociative disorder. The mean age was 23.6+/-8.67 years with female preponderance (n=40, 80% patients). Most of them were single, unemployed and belonged to urban population. Main stress was primary support group issue. Mixed category of dissociative disorder was highest (n=18, 38%) followed by unspecified and motor symptoms (n=13, 26%) in each group. Depression was present in 42 (84%) patients. Moderate depression was most frequent (n=19, 38%). Mixed dissociative symptoms were found in 38%, while 26% had motor and unspecified category of dissociative symptoms respectively. Depressive disorder was present in 42 (84%) cases of dissociative disorder with 38% having moderate depression.

  13. The dissociative subtype of posttraumatic stress disorder: rationale, clinical and neurobiological evidence, and implications.

    Science.gov (United States)

    Lanius, Ruth A; Brand, Bethany; Vermetten, Eric; Frewen, Paul A; Spiegel, David

    2012-08-01

    Clinical and neurobiological evidence for a dissociative subtype of posttraumatic stress disorder (PTSD) has recently been documented. A dissociative subtype of PTSD is being considered for inclusion in the forthcoming Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition (DSM-5) to address the symptoms of depersonalization and derealization found among a subset of patients with PTSD. This article reviews research related to the dissociative subtype including antecedent, concurrent, and predictive validators as well as the rationale for recommending the dissociative subtype. The relevant literature pertaining to the dissociative subtype of PTSD was reviewed. Latent class analyses point toward a specific subtype of PTSD consisting of symptoms of depersonalization and derealization in both veteran and civilian samples of PTSD. Compared to individuals with PTSD, those with the dissociative subtype of PTSD also exhibit a different pattern of neurobiological response to symptom provocation as well as a differential response to current cognitive behavioral treatment designed for PTSD. We recommend that consideration be given to adding a dissociative subtype of PTSD in the revision of the DSM. This facilitates more accurate analysis of different phenotypes of PTSD, assist in treatment planning that is informed by considering the degree of patients' dissociativity, will improve treatment outcome, and will lead to much-needed research about the prevalence, symptomatology, neurobiology, and treatment of individuals with the dissociative subtype of PTSD. © 2012 Wiley Periodicals, Inc.

  14. From Childhood Trauma to Adult Dissociation: The Role of PTSD and Alexithymia.

    Science.gov (United States)

    Terock, Jan; Van der Auwera, Sandra; Janowitz, Deborah; Spitzer, Carsten; Barnow, Sven; Miertsch, Martin; Freyberger, Harald J; Grabe, Hans-Jörgen

    The mechanism of how childhood trauma leads to increased risk for adult dissociation is not sufficiently understood. We sought to investigate the predicting effects and the putatively mediating roles of PTSD and alexithymia on the path from childhood trauma to adult dissociation. A total of 666 day-clinic outpatients were administered the Childhood Trauma Questionnaire (CTQ), the Toronto Alexithymia Scale (TAS-20), the Posttraumatic Diagnostic Scale (PDS), and the Dissociative Experiences Scale (DES) and controlled for sex, age, and the Global Symptom Index (GSI). Linear regression analyses and mediation analyses were applied. Independent predictive effects on dissociation were found for childhood trauma, alexithymia and PDS, even after adjusting for GSI. Effects of childhood neglect on dissociation were slightly stronger than of abuse. Alexithymia did not mediate the path from childhood trauma to dissociation. Mediation by PDS was specific for childhood abuse, with all PTSD symptom clusters being significantly involved. Childhood abuse and neglect are important predictors of dissociation. While the effects of abuse are mediated by PTSD, the mechanism of how neglect leads to dissociation remains unclear. The results further support the predictive value of alexithymia for adult dissociation above and beyond the effects of childhood trauma, PTSD, and GSI scores. © 2016 S. Karger AG, Basel.

  15. Does dissociation mediate the relationship between childhood trauma and hallucinations, delusions in first episode psychosis?

    Science.gov (United States)

    Sun, Pamela; Alvarez-Jimenez, Mario; Simpson, Katrina; Lawrence, Katherine; Peach, Natalie; Bendall, Sarah

    2018-04-11

    Childhood trauma has been linked to the presence of delusions and hallucinations in psychosis, although the mechanisms underlying this relationship require elucidation. Dissociation, characterized by disruptions to the integrative functioning of several core mental domains, has emerged as a potential mechanism. There is a paucity of research using a clinician-rated measure of dissociation to test the indirect effect of dissociation on the relationship between childhood trauma and psychotic symptoms. This study aimed to investigate whether dissociation mediated both the relationships between childhood trauma and hallucinations, and childhood trauma and delusions utilizing a clinician-administered measure of dissociation, namely the Structured Clinical Interview for DSM-IV Dissociative Disorders - Revised (SCID-D-R). Sixty-six first-episode psychosis (FEP) participants completed a research interview and questionnaires. Information about experiences of childhood trauma, psychosis, dissociation, general psychopathology and demographics were collected. When using the SCID-D-R, childhood trauma positively correlated with dissociation. Further, dissociation mediated the relationship between childhood trauma and delusions. Contrary to previous findings, we found no relationship between dissociation and hallucinations and no mediating effect of dissociation on the association between childhood trauma and hallucinations. The results of the SCID-D-R differed significantly from those of the Dissociative Experiences Scale-II (DES-II) which were consistent with previous research. Our findings are the first to use a clinician-rated measure to test the mediating effect of dissociation on the relationship between childhood trauma and positive symptoms (i.e., hallucinations and delusions). Given the discrepancies in results between the SCID-D-R and DES-II, how dissociation is measured in future research is an important consideration. The results add to a body of work that

  16. Imagining the impossible before breakfast: the relation between creativity, dissociation, and sleep

    Science.gov (United States)

    van Heugten - van der Kloet, Dalena; Cosgrave, Jan; Merckelbach, Harald; Haines, Ross; Golodetz, Stuart; Lynn, Steven Jay

    2015-01-01

    Dissociative symptoms have been related to higher rapid eye movement sleep density, a sleep phase during which hyperassociativity may occur. This may enhance artistic creativity during the day. To test this hypothesis, we conducted a creative photo contest to explore the relation between dissociation, sleep, and creativity. During the contest, participants (N = 72) took one photo per day for five consecutive days, based on specific daily themes (consisting of single words) and the instruction to take as creative a photo as possible each day. Furthermore, they completed daily measures of state dissociation and a short sleep diary. The photos and their captions were ranked by two professional photographers and two clinical psychologists based on creativity, originality, bizarreness, and quality. We expected that dissociative people would rank higher in the contest compared with low-dissociative participants, and that the most original photos would be taken on days when the participants scored highest on acute dissociation. We found that acute dissociation predicted a higher ranking on creativity. Poorer sleep quality and fewer hours of sleep predicted more bizarreness in the photos and captions. None of the trait measures could predict creativity. In sum, acute dissociation related to enhanced creativity. These findings contribute to our understanding of dissociative symptomatology. PMID:25859231

  17. Simulating the effect of hydrate dissociation on wellhead stability during oil and gas development in deepwater

    Science.gov (United States)

    Li, Qingchao; Cheng, Yuanfang; Zhang, Huaiwen; Yan, Chuanliang; Liu, Yuwen

    2018-02-01

    It is well known that methane hydrate has been identified as an alternative resource due to its massive reserves and clean property. However, hydrate dissociation during oil and gas development (OGD) process in deep water can affect the stability of subsea equipment and formation. Currently, there is a serious lack of studies over quantitative assessment on the effects of hydrate dissociation on wellhead stability. In order to solve this problem, ABAQUS finite element software was used to develop a model and to evaluate the behavior of wellhead caused by hydrate dissociation. The factors that affect the wellhead stability include dissociation range, depth of hydrate formation and mechanical properties of dissociated hydrate region. Based on these, series of simulations were carried out to determine the wellhead displacement. The results revealed that, continuous dissociation of hydrate in homogeneous and isotropic formations can causes the non-linear increment in vertical displacement of wellhead. The displacement of wellhead showed good agreement with the settlement of overlying formations under the same conditions. In addition, the shallower and thicker hydrate formation can aggravate the influence of hydrate dissociation on the wellhead stability. Further, it was observed that with the declining elastic modulus and Poisson's ratio, the wellhead displacement increases. Hence, these findings not only confirm the effect of hydrate dissociation on the wellhead stability, but also lend support to the actions, such as cooling the drilling fluid, which can reduce the hydrate dissociation range and further make deepwater operations safer and more efficient.

  18. Somatoform dissociation and traumatic experiences in patients with rheumatoid arthritis and fibromyalgia.

    Science.gov (United States)

    Näring, G W B; van Lankveld, W; Geenen, R

    2007-01-01

    Trauma and dissociation tend to be interrelated. The objective of this study was to examine the frequency of traumatic experiences and somatoform dissociation in patients with fibromyalgia syndrome (FMS) or rheumatoid arthritis (RA), two conditions that are both characterized by pain and disability. Patients with a diagnosis of FMS (2 male, 26 female; mean age 42 +/- 11 years) or RA (5 male, 46 female; mean age 46 +/- 10 years) completed the Fibromyalgia Impact Questionnaire (FIQ), the Somatoform Dissociation Questionnaire (SDQ), and the Traumatic Experience Checklist (TEC). Patients with FMS reported significantly higher levels of various forms of traumatization and dissociation than patients with RA. In patients with FMS, but not in patients with RA, there was a significant correlation between traumatization and dissociative symptoms. A possible dissociative disorder was indicated in 10% of the patients with FMS and 2% of the patients with RA. Traumatization experiences are frequent in FMS, but as compared to conversion disorder or dissociative identity disorder only a small subgroup of patients with FMS or RA shows the combination of traumatization and somatoform dissociation. The observation of somatoform dissociation calls for a broad treatment approach with a special role of the psychologist or psychiatrist.

  19. Pathway and mechanism of pH dependent human hemoglobin tetramer-dimer-monomer dissociations.

    Directory of Open Access Journals (Sweden)

    Yao-Xiong Huang

    Full Text Available Hemoglobin dissociation is of great interest in protein process and clinical medicine as well as in artificial blood research. However, the pathway and mechanisms of pH-dependent human Hb dissociation are not clear, whether Hb would really dissociate into monomers is still a question. Therefore, we have conducted a multi-technique investigation on the structure and function of human Hb versus pH. Here we demonstrate that tetramer hemoglobin can easily dissociate into dimer in abnormal pH and the tetramer → dimer dissociation is reversible if pH returns to normal physiological value. When the environmental pH becomes more acidic (8.0, Hb can further dissociate from dimer to monomer. The proportion of monomers increases while the fraction of dimers decreases as pH declines from 6.2 to 5.4. The dimer → monomer dissociation is accompanied with series changes of protein structure thus it is an irreversible process. The structural changes in the dissociated Hbs result in some loss of their functions. Both the Hb dimer and monomer cannot adequately carry and release oxygen to the tissues in circulation. These findings provide a comprehensive understanding on the pH-dependent protein transitions of human Hb, give guideline to explain complex protein processes and the means to control protein dissociation or re-association reaction. They are also of practical value in clinical medicine, blood preservation and blood substitute development.

  20. Dissociation of human follicle-stimulating hormone. Comparison with luteinizing hormone.

    Science.gov (United States)

    Reichert, L E; Ramsey, R B

    1975-04-25

    Rat testis tissue receptor assays were utilized to study the kinetics of dissociation of human follicle-stimulating hormone (hFSH) and luteinizing hormone (hLH) under varying conditions of urea concentration and pH. In these competitive protein binding assays, 125I-hFSH and 125I-hLH were the radioligands and hormone dissociation was followed by a decrease in the ability of the dissociating hormone to inhibit uptake of the radioligand by tissue receptors. Rate data for dissociation of the gonadotropins were analyzed for quality of fit to first or second order integrated rate equations by nonlinear regression analysis. Treatment of hFSH with 4 M urea at pH 8 and 25 degrees for 22 hours did not result in significant dissociation, whereas in 8 M urea, over 90% dissociation was observed. The rate of dissociation of hFSH in 8 M urea was increased approximately 4-fold by raising the temperature from 25 to 37 degrees. Similar results were obtained when dissociation of hFSH was followed through use of an accepted whole animal bioassay for FSH, thus confirming the reliability of the tissue receptor assay for such dissociation studies. Kinetic studies showed that hFSH was undissociated by incubation in 6 M urea of pH 8 after 4 hours at 25 degrees. In contrast, hLH was 90% dissociated under similar conditions. This differential rate of inactivation of hLH allowed preparation of hFSH having significant reduced levels of contaminating LH activity, as determined by tissue receptor assays and by whole animal bioassays. Marked differences were noted in the rate of dissociation of hFSH and hLH under acid conditions. hFSH completely dissociated after approximately 2 min of incubation of pH 2 (25 degrees), and over 90% dissociated after 15 min of incubation at pH 3. In contrast, hLH was dissociated 60% after 20 min of incubation at pH 2 (25 degrees) and 40% dissociated after 60 min at pH 3. Neither hormone was significantly dissociated at pH 4.4 after 60 min, but hFSH showed a

  1. Electrohydrodynamic flow caused by field-enhanced dissociation solely

    Science.gov (United States)

    Vasilkov, S. A.; Chirkov, V. A.; Stishkov, Yu. K.

    2017-06-01

    Electrohydrodynamic (EHD) flows emerge in dielectric liquids under the action of the Coulomb force and underlie energy-efficient techniques for heat and mass transfer. The key issue in the phenomena is the way how the net charge is created. One of the most promising, yet poorly studied charge formation mechanisms is the field-enhanced dissociation (or the Wien effect). So the paper studies an EHD flow caused solely by the effect by virtue of both experiment and computer simulation. To preclude the competing mechanism of charge formation—the injection—a new EHD system of a special design was examined. Its main feature is the use of solid insulation to create the region of the strong electric field far from the electrode metal surfaces. The experimental study used the particle image velocimetry technique to observe velocity distributions, whereas the computations were based on the complete set of electrohydrodynamic equations employing the commercial software package COMSOL Multiphysics. Spatial distributions of key quantities (including the ion concentrations, the total space charge density, and the velocity) and the acting forces were obtained in the computer simulation and were analyzed. The experimental flow structure was observed for a number of voltages up to 30 kV. The comparison of the numerical and experimental results yielded a good quantitative agreement for strong electric fields though some overshoot was observed for weak ones. The results allow concluding on the applicability of the Onsager theory of the field-enhanced dissociation in the context of EHD flows.

  2. TMS produces two dissociable types of speech disruption.

    Science.gov (United States)

    Stewart, L; Walsh, V; Frith, U; Rothwell, J C

    2001-03-01

    We aimed to use repetitive transcranial magnetic stimulation (rTMS) to disrupt speech with the specific objective of dissociating speech disruption according to whether or not it was associated with activation of the mentalis muscle. Repetitive transcranial magnetic stimulation (rTMS) was applied over two sites of the right and left hemisphere while subjects counted aloud and recited the days of the week, months of the year, and nursery rhymes. Analysis of EMG data and videotaped recordings showed that rTMS applied over a posterior site, lateral to the motor hand area of both the right and the left hemisphere resulted in speech disruption that was accompanied by activation of the mentalis muscle, while rTMS applied over an anterior site on the left but not the right hemisphere resulted in speech disruption that was dissociated from activation of the mentalis muscle. The findings provide a basis for the use of subthreshold stimulation over the extrarolandic speech disruption site in order to probe the functional properties of this area and to test psychological theories of linguistic function. Copyright 2001 Academic Press.

  3. Dissociation of dilute immiscible copper alloy thin films

    International Nuclear Information System (INIS)

    Barmak, K.; Lucadamo, G. A.; Cabral, C. Jr.; Lavoie, C.; Harper, J. M. E.

    2000-01-01

    The dissociation behavior of dilute, immiscible Cu-alloy thin films is found to fall into three broad categories that correlate most closely with the form of the Cu-rich end of the binary alloy phase diagrams. Available thermodynamic and tracer diffusion data shed further light on alloy behavior. Eight alloying elements were selected for these studies, with five elements from groups 5 and 6, two from group 8, and one from group 11 of the periodic table. They are respectively V, Nb, Ta, Cr, Mo, Fe, Ru, and Ag. The progress of precipitation in approximately 500-nm-thick alloy films, containing 2.5-3.8 at. % solute, was followed with in situ resistance and stress measurements as well as with in situ synchrotron x-ray diffraction. In addition, texture analysis and transmission electron microscopy were used to investigate the evolution of microstructure and texture of Cu(Ta) and Cu(Ag). For all eight alloys, dissociation occurred upon heating, with the rejection of solute and evolution of microstructure often occurring in multiple steps that range over several hundred degrees between approximately 100 and 900 degree sign C. However, in most cases, substantial reductions in resistivity of the films took place below 400 degree sign C, at temperatures of interest to copper metallization schemes for silicon chip technology. (c) 2000 American Institute of Physics

  4. Dissociating Simon and affordance compatibility effects: silhouettes and photographs.

    Science.gov (United States)

    Pappas, Zissis

    2014-12-01

    When a graspable object's handle is oriented to the same side as the response hand, responses are quicker and more accurate than when it is oriented to the opposite side. This effect has been attributed to the affordance of the object's handle (Tucker & Ellis, 1998). Recent findings suggest this effect results instead from an abstract spatial response code (i.e., Simon effect; Cho & Proctor, 2010). However, the stimuli used in these previous studies differ in the amount of object and environmental depth information they contain, which may be critical to conveying an affordance. This information could explain these disparate findings as well as dissociate Simon and affordance compatibility effects. Four experiments demonstrate that the Simon effect results from the absence of this information, as in a silhouette, and the affordance effect results from its presence, as in a photograph. A fifth experiment confirmed that modifying information associated with the affordance, rather than the modification itself, produced the effects observed in the previous experiments. These findings support the following: (a) the internal details of an object and environmental depth can dissociate Simon and affordance compatibility effects, (b) this information is necessary to convey the object's graspable affordance, and (c) the outer shape of the object is not sufficient to elicit an affordance effect. These findings are discussed in relation to the theory of embodied cognition. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Pre-Traumatic Vaccination Intervention: can dissociative symptoms be reduced?

    Science.gov (United States)

    Essar, Nir; Palgi, Yuval; Saar, Ronen; Ben-Ezra, Menachem

    2010-01-01

    The Pre-Traumatic Vaccination Intervention (PTV) has been developed in an attempt to help rescue personnel cope with anticipated and non-anticipated disasters, and to prevent trauma-related mental disorders during and after a traumatogenic exposure. Contrary to the generally accepted approach of treating trauma after it has occurred, the PTV has been designed to be administered prior to the potentially traumatic event. Based on empirical findings, the PTV training techniques were designed to prepare the participants for distressful situations. Trainees were gradually exposed to increasingly severe sights using cognitive-behavioral techniques along with foreseen situations relating to their profession. Various interventions were aimed at normalizing using personal resources and implementing relaxation techniques. The PTV was administrated as part of the Israeli Defense Forces rescue personnel's and military police training courses. The results of an uncontrolled, preliminary study suggest that the intervention reduced the level of dissociation leading to more awareness to the traumatic event's details, less suffering, lower probability of making mistakes, and increased likelihood of returning to normal functioning. Lower dissociation may suggest a lower probability to be diagnosed with post-traumatic stress disorder among rescue personnel.

  6. Generalized Hartree-Fock Description of Molecular Dissociation.

    Science.gov (United States)

    Jiménez-Hoyos, Carlos A; Henderson, Thomas M; Scuseria, Gustavo E

    2011-09-13

    An electronic structure method is said to be size-consistent if the energy of noninteracting fragments is the same when the fragments are treated in a supermolecule approach or are treated in isolation. Size consistency is often violated by Hartree-Fock when symmetries of the exact wave function are imposed on the Hartree-Fock determinant. Relaxing the requirement that the Hartree-Fock wave function be a spin eigenfunction leads to unrestricted Hartree-Fock, which is often (but not always) size-consistent. In this Perspective, we discuss the usually forgotten fact that imposing none of the exact symmetries in what is known as generalized Hartree-Fock allows Hartree-Fock to always be size-consistent and allows size extensive correlated methods such as coupled cluster theory to also be size-consistent. Furthermore, with all symmetries broken, dissociation curves connect the molecule to the fragments better than with symmetries imposed, although the curves are not smooth and show derivative discontinuities akin to unphysical phase transitions. In many cases, correlated dissociation curves based on this generalized Hartree-Fock reference are discontinuous.

  7. Dissociative electron attachment and charge transfer in condensed matter

    International Nuclear Information System (INIS)

    Bass, A.D.; Sanche, L.

    2003-01-01

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

  8. Dissociated Crossed Speech Areas in a Tumour Patient

    Directory of Open Access Journals (Sweden)

    Jörg Mauler

    2017-05-01

    Full Text Available In the past, the eloquent areas could be deliberately localised by the invasive Wada test. The very rare cases of dissociated crossed speech areas were accidentally found based on the clinical symptomatology. Today functional magnetic resonance imaging (fMRI-based imaging can be employed to non-invasively localise the eloquent areas in brain tumour patients for therapy planning. A 41-year-old, left-handed man with a low-grade glioma in the left frontal operculum extending to the insular cortex, tension headaches, and anomic aphasia over 5 months underwent a pre-operative speech area localisation fMRI measurement, which revealed the evidence of the transhemispheric disposition, where the dominant Wernicke speech area is located on the left and the Broca’s area is strongly lateralised to the right hemisphere. The outcome of the Wada test and the intraoperative cortico-subcortical stimulation mapping were congruent with this finding. After tumour removal, language area function was fully preserved. Upon the occurrence of brain tumours with a risk of impaired speech function, the rare dissociate crossed speech areas disposition may gain a clinically relevant meaning by allowing for more extended tumour removal. Hence, for its identification, diagnostics which take into account both brain hemispheres, such as fMRI, are recommended.

  9. Dissociating Attention Effects from Categorical Perception with ERP Functional Microstates.

    Directory of Open Access Journals (Sweden)

    Benjamin Dering

    Full Text Available When faces appear in our visual environment we naturally attend to them, possibly to the detriment of other visual information. Evidence from behavioural studies suggests that faces capture attention because they are more salient than other types of visual stimuli, reflecting a category-dependent modulation of attention. By contrast, neuroimaging data has led to a domain-specific account of face perception that rules out the direct contribution of attention, suggesting a dedicated neural network for face perception. Here we sought to dissociate effects of attention from categorical perception using Event Related Potentials. Participants viewed physically matched face and butterfly images, with each category acting as a target stimulus during different blocks in an oddball paradigm. Using a data-driven approach based on functional microstates, we show that the locus of endogenous attention effects with ERPs occurs in the N1 time range. Earlier categorical effects were also found around the level of the P1, reflecting either an exogenous increase in attention towards face stimuli, or a putative face-selective measure. Both category and attention effects were dissociable from one another hinting at the role that faces may play in early capturing of attention before top-down control of attention is observed. Our data support the conclusion that certain object categories, in this experiment, faces, may capture attention before top-down voluntary control of attention is initiated.

  10. High fidelity modeling of thermal relaxation and dissociation of oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Andrienko, Daniil A., E-mail: daniila@umich.edu; Boyd, Iain D. [Department of Aerospace Engineering, University of Michigan, 1320 Beal Ave., Ann Arbor, Michigan 48108 (United States)

    2015-11-15

    A master equation study of vibrational relaxation and dissociation of oxygen is conducted using state-specific O{sub 2}–O transition rates, generated by extensive trajectory simulations. Both O{sub 2}–O and O{sub 2}–O{sub 2} collisions are concurrently simulated in the evolving nonequilibrium gas system under constant heat bath conditions. The forced harmonic oscillator model is incorporated to simulate the state-to-state relaxation of oxygen in O{sub 2}–O{sub 2} collisions. The system of master equations is solved to simulate heating and cooling flows. The present study demonstrates the importance of atom-diatom collisions due to the extremely efficient energy randomization in the intermediate O{sub 3} complex. It is shown that the presence of atomic oxygen has a significant impact on vibrational relaxation time at temperatures observed in hypersonic flow. The population of highly-excited O{sub 2} vibrational states is affected by the amount of atomic oxygen when modeling the relaxation under constant heat bath conditions. A model of coupled state-to-state vibrational relaxation and dissociation of oxygen is also discussed.

  11. Dissociating response conflict and error likelihood in anterior cingulate cortex.

    Science.gov (United States)

    Yeung, Nick; Nieuwenhuis, Sander

    2009-11-18

    Neuroimaging studies consistently report activity in anterior cingulate cortex (ACC) in conditions of high cognitive demand, leading to the view that ACC plays a crucial role in the control of cognitive processes. According to one prominent theory, the sensitivity of ACC to task difficulty reflects its role in monitoring for the occurrence of competition, or "conflict," between responses to signal the need for increased cognitive control. However, a contrasting theory proposes that ACC is the recipient rather than source of monitoring signals, and that ACC activity observed in relation to task demand reflects the role of this region in learning about the likelihood of errors. Response conflict and error likelihood are typically confounded, making the theories difficult to distinguish empirically. The present research therefore used detailed computational simulations to derive contrasting predictions regarding ACC activity and error rate as a function of response speed. The simulations demonstrated a clear dissociation between conflict and error likelihood: fast response trials are associated with low conflict but high error likelihood, whereas slow response trials show the opposite pattern. Using the N2 component as an index of ACC activity, an EEG study demonstrated that when conflict and error likelihood are dissociated in this way, ACC activity tracks conflict and is negatively correlated with error likelihood. These findings support the conflict-monitoring theory and suggest that, in speeded decision tasks, ACC activity reflects current task demands rather than the retrospective coding of past performance.

  12. Characterizing Interferences in an NOy Thermal Dissociation Inlet

    Science.gov (United States)

    Womack, C.; Veres, P. R.; Brock, C. A.; Neuman, J. A.; Eilerman, S. J.; Zarzana, K. J.; Dube, W. P.; Wild, R. J.; Wooldridge, P. J.; Cohen, R. C.; Brown, S. S.

    2016-12-01

    Nitrogen oxides (NOx = NO and NO2) are emitted into the troposphere by various anthropogenic and natural sources, and contribute to increased levels of ambient ozone. Reactive nitrogen species (NOy), which include nitric acid, peroxy acetyl and organic nitrates, and other species, serve as reservoirs and sinks for NOx, thus influencing O3 production. Their detection is therefore critical to understanding ozone chemistry. However, accurate measurements of NOy have proven to be difficult to obtain, and measurements of total NOy sometimes do not agree with the sum of measurements of its individual components. In recent years, quartz thermal dissociation (TD) inlets have been used to thermally convert all NOy species to NO2, followed by detection by techniques such as laser induced fluorescence (LIF) or cavity ringdown spectroscopy (CRDS). Here we discuss recent work in characterizing the NOy channel of our four-channel TD-CRDS instrument. In particular, we have examined the thermal conversion efficiency of several representative NOy species under a range of experimental conditions. We find that under certain conditions, the conversion efficiency is sensitive to inlet residence time and to the concentration of other trace gases found in ambient sampling, such as ozone. We also report the thermal dissociation curves of N2O5 and ammonium nitrate aerosol, and discuss the interferences observed when ammonia and ozone are co-sampled in the inlet.

  13. Biexciton Dissociation Efficiency at Quantum Dot-Oxide Interfaces

    Science.gov (United States)

    Bonn, Mischa; Wang, Hai; Canovas, Enrique

    Harvesting multiexcitons populating semiconductor quantum dots (generated by carrier multiplication, CM) has been proposed as a path towards higher efficiencies in photovoltaic devices. Although CM efficiency has been widely interrogated in colloidal QD solutions, less focus has been placed on the physics regarding biexciton collection at electrodes. We investigate interfacial biexciton transfer dynamics from PbS quantum dots directly nucleated onto mesoporous SnO2 films as a function of impinging photon flux and photon energy. A priori, this system seems very well-suited for achieving efficient biexciton dissociation, as the ultrafast QD-to-oxide transfer rate for 800nm excitation is substantially faster than Auger relaxation. Remarkably, the biexciton dissociation efficiency is below the detection efficiency, i.e. essentially zero. This seemingly counterintuitive result can be understood by noting that efficient hot electron transfer at the QD-oxide interface can compete with CM within the QDs. Hot electron transfer is observed to occur on sub-100 fs timescales, nulling the CM efficiency. Implications of these results for solar energy conversion are discussed.

  14. Dissociative Ionization of Argon Dimer by Intense Femtosecond Laser Pulses.

    Science.gov (United States)

    Cheng, Qian; Xie, Xiguo; Yuan, Zongqiang; Zhong, Xunqi; Liu, Yunquan; Gong, Qihuang; Wu, Chengyin

    2017-05-25

    We experimentally and theoretically studied dissociative ionization of argon dimer driven by intense femtosecond laser pulses. In the experiment, we measured the ion yield and the angular distribution of fragmental ions generated from the dissociative ionization channels of (1,1) (Ar 2 2+ → Ar + + Ar + ) and (2,1) (Ar 2 3+ → Ar 2+ + Ar + ) using a cold target recoil ion momentum spectroscopy. The channel ratio of (2,1)/(1,1) is 4.5-7.5 times of the yield ratio of double ionization to single ionization of argon monomer depending on the laser intensity. The measurement verified that the ionization of Ar + is greatly enhanced if there exists a neighboring Ar + separated by a critical distance. In addition, the fragmental ions exhibit an anisotropic angular distribution with the peak along the laser polarization direction and the full width at half maximum becomes broader with increasing laser intensity. Using a full three-dimensional classical ensemble model, we calculated the angle-dependent multiple ionization probability of argon dimer in intense laser fields. The results show that the experimentally observed anisotropic angular distribution of fragmental ions can be attributed to the angle-dependent enhanced ionization of the argon dimer in intense laser fields.

  15. Artificial consciousness and the consciousness-attention dissociation.

    Science.gov (United States)

    Haladjian, Harry Haroutioun; Montemayor, Carlos

    2016-10-01

    Artificial Intelligence is at a turning point, with a substantial increase in projects aiming to implement sophisticated forms of human intelligence in machines. This research attempts to model specific forms of intelligence through brute-force search heuristics and also reproduce features of human perception and cognition, including emotions. Such goals have implications for artificial consciousness, with some arguing that it will be achievable once we overcome short-term engineering challenges. We believe, however, that phenomenal consciousness cannot be implemented in machines. This becomes clear when considering emotions and examining the dissociation between consciousness and attention in humans. While we may be able to program ethical behavior based on rules and machine learning, we will never be able to reproduce emotions or empathy by programming such control systems-these will be merely simulations. Arguments in favor of this claim include considerations about evolution, the neuropsychological aspects of emotions, and the dissociation between attention and consciousness found in humans. Ultimately, we are far from achieving artificial consciousness. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Dissociative electron attachment on surfaces and in bulk media

    International Nuclear Information System (INIS)

    Fabrikant, Ilya I.

    2007-01-01

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

  17. Semiclassical calculation for collision induced dissociation. II. Morse oscillator model

    International Nuclear Information System (INIS)

    Rusinek, I.; Roberts, R.E.

    1978-01-01

    A recently developed semiclassical procedure for calculating collision induced dissociation probabilities P/sup diss/ is applied to the collinear collision between a particle and a Morse oscillator diatomic. The particle--diatom interaction is described with a repulsive exponential potential function. P/sup diss/ is reported for a system of three identical particles, as a function of collision energy E/sub t/ and initial vibrational state of the diatomic n 1 . The results are compared with the previously reported values for the collision between a particle and a truncated harmonic oscillator. The two studies show similar features, namely: (a) there is an oscillatory structure in the P/sup diss/ energy profiles, which is directly related to n 1 ; (b) P/sup diss/ becomes noticeable (> or approx. =10 -3 ) for E/sub t/ values appreciably higher than the energetic threshold; (c) vibrational enhancement (inhibition) of collision induced dissociation persists at low (high) energies; and (d) good agreement between the classical and semiclassical results is found above the classical dynamic threshold. Finally, the convergence of P/sup diss/ for increasing box length is shown to be rapid and satisfactory

  18. MMPI-2 Item Endorsements in Dissociative Identity Disorder vs. Simulators.

    Science.gov (United States)

    Brand, Bethany L; Chasson, Gregory S; Palermo, Cori A; Donato, Frank M; Rhodes, Kyle P; Voorhees, Emily F

    2016-03-01

    Elevated scores on some MMPI-2 (Minnesota Multiphasic Inventory-2) validity scales are common among patients with dissociative identity disorder (DID), which raises questions about the validity of their responses. Such patients show elevated scores on atypical answers (F), F-psychopathology (Fp), atypical answers in the second half of the test (FB), schizophrenia (Sc), and depression (D) scales, with Fp showing the greatest utility in distinguishing them from coached and uncoached DID simulators. In the current study, we investigated the items on the MMPI-2 F, Fp, FB, Sc, and D scales that were most and least commonly endorsed by participants with DID in our 2014 study and compared these responses with those of coached and uncoached DID simulators. The comparisons revealed that patients with DID most frequently endorsed items related to dissociation, trauma, depression, fearfulness, conflict within family, and self-destructiveness. The coached group more successfully imitated item endorsements of the DID group than did the uncoached group. However, both simulating groups, especially the uncoached group, frequently endorsed items that were uncommonly endorsed by the DID group. The uncoached group endorsed items consistent with popular media portrayals of people with DID being violent, delusional, and unlawful. These results suggest that item endorsement patterns can provide useful information to clinicians making determinations about whether an individual is presenting with DID or feigning. © 2016 American Academy of Psychiatry and the Law.

  19. Women With Dissociative Identity Disorder Who Experience Intimate Partner Violence.

    Science.gov (United States)

    Snyder, Briana L

    2018-02-15

    Women with dissociative identity disorder (DID) are significantly more likely than other women to experience intimate partner violence (IPV). The purpose of this qualitative investigation was to explicate the experiences of women with DID who experience IPV and describe how they cope. Grounded theory was used to conduct this investigation. Purposive sampling was used to recruit participants (N = 5) for face-to-face, semi-structured interviews. Verbatim transcripts were coded and categorized, and reflective memos were developed to explicate substantive categories. Women with DID used coping strategies that were consistent with their diagnoses, such as switching and dissociating. These coping mechanisms reflect past self-preservation strategies that were developed in association with severe childhood maltreatment. Women with DID who experienced IPV sought to mitigate and safeguard themselves from danger using strategies they developed as maltreated children. Nurses can use these findings to better recognize and understand the motivations and behaviors of women with DID who experience IPV. [Journal of Psychosocial Nursing and Mental Health Services, xx(x), xx-xx.]. Copyright 2018, SLACK Incorporated.

  20. Trauma, innocence and the core complex of dissociation.

    Science.gov (United States)

    Kalsched, Donald E

    2017-09-01

    Trauma survivors often lament that they have lost their innocence or lost their souls and that something vulnerable and whole about themselves has been 'broken' or annihilated. Yet when the psychotherapeutic relationship begins, and symbolic material from dreams and the transference emerges, discernible patterns become apparent, indicating that a core of innocence and vitality has not been totally lost or annihilated. On the contrary, it has been 'saved' by dissociation and its system of inner objects and their protective and/or persecutory narrative 'scripts' or 'schemas'. The dissociative system splits off a wounded, orphaned 'child' in the psyche and clinging to this 'child' is a penumbra of innocence that apparently must be preserved at all costs. Unfortunately the costs of preservation are high because such encapsulated innocence becomes malignant, and the inner world turns perverse and destructive. Only when the wounded, orphaned, and innocent part of the personality is allowed to suffer experience again - this time with the promise of a new outcome - can true healing of trauma occur. How to facilitate this authentic suffering in the face of powerful resistances thrown up by the 'system', will be the focus of this paper. © 2017, The Society of Analytical Psychology.

  1. Theoretical investigation on the adsorption and dissociation behaviors of TiCl4 on pyrolytic carbon surface

    Science.gov (United States)

    Jin, Na; Yang, Yanqing; Luo, Xian; Liu, Shuai; Li, Pengtao

    2018-01-01

    We present a theoretical investigation of the reaction mechanism of TiCl4 dissociation on pyrolytic carbon surface and discuss the influence of H atom on adsorption and dissociation behaviors of TiCl4 by using density functional theory. The adsorption behaviors of TiClx (x = 4-0) and the interactions between pre-adsorbed H atom and TiClx are studied by calculating adsorption energies Eads and interaction energies HTi, respectively. The pre-adsorbed H atom significantly facilitates the adsorption of TiClx on pyrolytic carbon surface. Specially, TiCl3 adsorption on pyrolytic carbon surface converts from an endothermic process into an exothermic process due to the present of pre-adsorbed H atom. The calculation results of HTi show that the interactions between pre-adsorbed H atom and TiClx are attractive. The dissociation of TiCl4 on pre-adsorbed H pyrolytic carbon surface is an exothermic process, and TiCl4 → TiCl3 is the limited step. The dissociation barriers of each step are less than 1.5 eV except for TiCl → Ti, which does not need to overcome any barriers, that is to say, once TiCl is adsorbed on pre-adsorbed H surface the reaction of TiCl → Ti spontaneously occurs. It thus can be concluded that the dissociation of TiCl4 on pyrolytic carbon surface is a favorable process as long as H2 molecular have decomposed into atomic H and adsorbed on pyrolytic carbon surface, and the intermediate species (TiCl3, TiCl2 and TiCl) play an important role on the titanium CVD deposition. We also study the adsorption behavior of H atom and the dissociation behavior of H2 molecular on pyrolytic carbon surface.

  2. 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

  3. Dissociations Between Fluency And Agrammatism In Primary Progressive Aphasia

    Science.gov (United States)

    Thompson, Cynthia K.; Cho, Soojin; Hsu, Chien-Ju; Wieneke, Christina; Rademaker, Alfred; Weitner, Bing Bing; Mesulam, M-Marsel; Weintraub, Sandra

    2011-01-01

    Background Classical aphasiology, based on the study of stroke sequelae, fuses speech fluency and grammatical ability. Nonfluent (Broca's) aphasia often is accompanied by agrammatism; whereas in the fluent aphasias grammatical deficits are not typical. The assumption that a similar relationship exists in primary progressive aphasia (PPA) has led to the dichotomization of this syndrome into fluent and nonfluent subtypes. Aims This study compared elements of fluency and grammatical production in the narrative speech of individuals with PPA to determine if they can be dissociated from one another. Method Speech samples from 37 individuals with PPA, clinically assigned to agrammatic (N=11), logopenic (N=20) and semantic (N=6) subtypes, and 13 cognitively healthy control participants telling the “Cinderella Story” were analyzed for fluency (i.e., words per minute (WPM) and mean length of utterance in words (MLU-W)) and grammaticality (i.e., the proportion of grammatically correct sentences, open-to-closed-class word ratio, noun-to-verb ratio, and correct production of verb inflection, noun morphology, and verb argument structure.) Between group differences were analyzed for each variable. Correlational analyses examined the relation between WPM and each grammatical variable, and an off-line measure of sentence production. Outcomes And Results Agrammatic and logopenic groups both had lower scores on the fluency measures and produced significantly fewer grammatical sentences than did semantic and control groups. However, only the agrammatic group evinced significantly impaired production of verb inflection and verb argument structure. In addition, some semantic participants showed abnormal open-to-closed and noun-to-verb ratios in narrative speech. When the sample was divided on the basis of fluency, all the agrammatic participants fell in the nonfluent category. The logopenic participants varied in fluency but those with low fluency showed variable performance on

  4. Isotope effects in photo dissociation of ozone with visible light

    Science.gov (United States)

    Früchtl, Marion; Janssen, Christof; Röckmann, Thomas

    2014-05-01

    Ozone (O3) plays a key role for many chemical oxidation processes in the Earth's atmosphere. In these chemical reactions, ozone can transfer oxygen to other trace gases. This is particularly interesting, since O3 has a very peculiar isotope composition. Following the mass dependent fractionation equation δ17O = 0.52 * δ18O, most fractionation processes depend directly on mass. However, O3 shows an offset to the mass dependent fractionation line. Processes, which show such anomalies, are termed mass independent fractionations (MIF). A very well studied example for a chemical reaction that leads to mass independent fractionation is the O3 formation reaction. To what degree O3 destruction reactions need to be considered in order to understand the isotope composition of atmospheric O3 is still not fully understood and an open question within scientific community. We set up new experiments to investigate the isotope effect resulting from photo dissociation of O3 in the Chappuis band (R1). Initial O3 is produced by an electric discharge. After photolysis O3 is collected in a cold trap at the triple point temperature of nitrogen (63K). O3 is then converted to O2 in order to measure the oxygen isotopes of O3 using isotope ratio mass spectrometry. To isolate O3 photo dissociation (R1) from O3 decomposition (R2) and secondary O3 formation (R3), we use varying amounts of carbon monoxide (CO) as O atom quencher (R4). In this way we suppress the O + O3 reaction (R3) and determine the isotope fractionation in R1 and R2 separately. We present first results on the isotope effects in O3 photo dissociation with visible light in the presence of different bath gases. Results are interpreted based on chemical kinetics modeling. (R1) O3 + hυ → O (3P) + O2 (R2) O3 + O (3P) → 2 O2 (R3) O + O2 + M → O3 + M (R4) O (3P) + CO + M → CO2 + M

  5. Dissociative Experiences, Creative Imagination, and Artistic Production in Students of Fine Arts

    Science.gov (United States)

    Perez-Fabello, Maria Jose; Campos, Alfredo

    2011-01-01

    The current research was designed to assess the influence of dissociative experiences and creative imagination on the artistic production of Fine Arts students of the University of Vigo (Spain). The sample consisted of 81 students who were administered the Creative Imagination Scale and The Dissociative Experiences Scale. To measure artistic…

  6. Use of an intense microwave laser to dissociate a diatomic molecule ...

    Indian Academy of Sciences (India)

    respectively, the conclusion is reached theoretically and computationally that it is possible to dissociate the CO molecule, modelled as a Morse oscillator. It is predicted that for above-threshold dissociation. (ATD), the molecule should absorb 1044 photons of the given wavelength in order to reach the lowest edge of.

  7. Infrared multiple-photon dissociation spectroscopy of group II metal complexes with salicylate

    NARCIS (Netherlands)

    Dain, R.P.; Gresham, G.; Groenewold, G.S.; Steill, J.D.; Oomens, J.; van Stipdonk, M.J.

    2011-01-01

    Ion trap tandem mass spectrometry with collision-induced dissociation, and the combination of infrared multiple-photon dissociation (IRMPD) spectroscopy and density functional theory (DFT) calculations, were used to characterize singly charged, 1:1 complexes of Ca2+, Sr2+ and Ba2+ with salicylate.

  8. Infrared multiple-photon dissociation spectroscopy of group II metal complexes with salicylate

    NARCIS (Netherlands)

    Dain, R. P.; Gresham, G.; Groenewold, G. S.; Steill, J. D.; Oomens, J.; van Stipdonk, M. J.

    2011-01-01

    Ion trap tandem mass spectrometry with collision-induced dissociation, and the combination of infrared multiple-photon dissociation (IRMPD) spectroscopy and density functional theory (DFT) calculations, were used to characterize singly charged, 1: 1 complexes of Ca2+, Sr2+ and Ba2+ with salicylate.

  9. An evaluation of nonclinical dissociation utilizing a virtual environment shows enhanced working memory and attention.

    Science.gov (United States)

    Saidel-Goley, Isaac N; Albiero, Erin E; Flannery, Kathleen A

    2012-02-01

    Dissociation is a mental process resulting in the disruption of memory, perception, and sometimes identity. At a nonclinical level, only mild dissociative experiences occur. The nature of nonclinical dissociation is disputed in the literature, with some asserting that it is a beneficial information processing style and others positing that it is a psychopathological phenomenon. The purpose of this study was to further the understanding of nonclinical dissociation with respect to memory and attention, by including a more ecologically valid virtual reality (VR) memory task along with standard neuropsychological tasks. Forty-five undergraduate students from a small liberal arts college in the northeast participated for course credit. The participants completed a battery of tasks including two standard memory tasks, a standard attention task, and an experimental VR memory task; the VR task included immersion in a virtual apartment, followed by incidental object-location recall for objects in the virtual apartment. Support for the theoretical model portraying nonclinical dissociation as a beneficial information processing style was found in this study. Dissociation scores were positively correlated with working memory scores and attentional processing scores on the standard neuropsychological tasks. In terms of the VR task, dissociation scores were positively correlated with more false positive memories that could be the result of a tendency of nonclinical highly dissociative individuals to create more elaborative schemas. This study also demonstrates that VR paradigms add to the prediction of cognitive functioning in testing protocols using standard neuropsychological tests, while simultaneously increasing ecological validity.

  10. Structural brain aberrations associated with the dissociative subtype of post-traumatic stress disorder.

    Science.gov (United States)

    Daniels, J K; Frewen, P; Theberge, J; Lanius, R A

    2016-03-01

    One factor potentially contributing to the heterogeneity of previous results on structural grey matter alterations in adult participants suffering from post-traumatic stress disorder (PTSD) is the varying levels of dissociative symptomatology. The aim of this study was therefore to test whether the recently defined dissociative subtype of PTSD characterized by symptoms of depersonalization and derealization is characterized by specific differences in volumetric brain morphology. Whole-brain MRI data were acquired for 59 patients with PTSD. Voxel-based morphometry was carried out to test for group differences between patients classified as belonging (n = 15) vs. not belonging (n = 44) to the dissociative subtype of PTSD. The correlation between dissociation (depersonalization/derealization) severity and grey matter volume was computed. Patients with PTSD classified as belonging to the dissociative subtype exhibited greater grey matter volume in the right precentral and fusiform gyri as well as less volume in the right inferior temporal gyrus. Greater dissociation severity was associated with greater volume in the right middle frontal gyrus. The results of this first whole-brain investigation of specific grey matter volume in dissociative subtype PTSD indentified structural aberrations in regions subserving the processing and regulation of emotional arousal. These might constitute characteristic biomarkers for the dissociative subtype PTSD. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. A Systematic Chart Review of Inpatient Population with Childhood Dissociative Disorder

    Science.gov (United States)

    Prabhuswamy, Mukesh; Jairam, Rajeev; Srinath, Shoba; Girimaji, Satish; Seshadri, Shekhar P.

    2006-01-01

    Objective: To study the socio-demographic factors, clinical characteristics, and long-term outcome of dissociative disorders in inpatient children and adolescents. Methods: Chart data of forty-four subjects (8-15 years) with a diagnosis of dissociative disorder admitted to a specialist Child and Adolescent Psychiatry (CAP) unit between September…

  12. Cognitive Abuse within the Incestuous Family as a Factor in the Development of Dissociative Identity Disorder

    Science.gov (United States)

    Reed-Gavish, Maya

    2013-01-01

    The polarized nature of the ongoing controversies surrounding the genesis and validity of dissociative identity disorder pit advocates who see and work with dissociative identity disorder sufferers against skeptics who claim it to be an artificial iatrogenically produced phenomenon. This paper suggests that such a dichotomy is unwarranted and…

  13. Model of the dissociative recombination of molecular ions based on the statistical 'phase-space theory'

    International Nuclear Information System (INIS)

    Foltin, M.; Lukac, P.; Morva, I.; Foltin, V.

    2004-01-01

    In the paper the statistical 'phase-space theory' extended for chemical reactions and for dissociative recombination of polyatomic ions is applied to the indirect and direct dissociative recombination of diatomic ions with electrons. Numerical calculations are made for molecular neon ion. The good agreement is obtained with experimental results (Authors)

  14. Dissociative Electron Attachment to Carbon Dioxide via the 8.2 eV Feshbach resonance

    Energy Technology Data Exchange (ETDEWEB)

    Slaughter, Dan; Adaniya, Hidihito; Rescigno, Tom; Haxton, Dan; Orel, Ann; McCurdy, Bill; Belkacem, Ali

    2011-08-17

    Momentum imaging experiments on dissociative electron attachment (DEA) to CO{sub 2} are combined with the results of ab initio calculations to provide a detailed and consistent picture of the dissociation dynamics through the 8.2 eV resonance, which is the major channel for DEA in CO{sub 2}. The present study resolves several puzzling misconceptions about this system.

  15. Dissociative electron attachment to carbon dioxide via the 8.2 eV Feshbach resonance

    Energy Technology Data Exchange (ETDEWEB)

    Slaughter, D S; Adaniya, H; Rescigno, T N; Haxton, D J; Belkacem, A [Lawrence Berkeley National Laboratory, Chemical Sciences, Berkeley, CA 94720 (United States); Orel, A E [Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95616 (United States); McCurdy, C W [Department of Chemistry, University of California, Davis, CA 95616 (United States)

    2011-10-28

    Momentum imaging experiments on dissociative electron attachment (DEA) to CO{sub 2} are combined with the results of ab initio calculations to provide a detailed and consistent picture of the dissociation dynamics through the 8.2 eV resonance, which is the major channel for DEA in CO{sub 2}. The present study resolves several puzzling misconceptions about this system.

  16. Surface Induced Dissociation Yields Quaternary Substructure of Refractory Noncovalent Phosphorylase B and Glutamate Dehydrogenase Complexes

    Science.gov (United States)

    Ma, Xin; Zhou, Mowei; Wysocki, Vicki H.

    2014-03-01

    Ion mobility (IM) and tandem mass spectrometry (MS/MS) coupled with native MS are useful for studying noncovalent protein complexes. Collision induced dissociation (CID) is the most common MS/MS dissociation method. However, some protein complexes, including glycogen phosphorylase B kinase (PHB) and L-glutamate dehydrogenase (GDH) examined in this study, are resistant to dissociation by CID at the maximum collision energy available in the instrument. Surface induced dissociation (SID) was applied to dissociate the two refractory protein complexes. Different charge state precursor ions of the two complexes were examined by CID and SID. The PHB dimer was successfully dissociated to monomers and the GDH hexamer formed trimeric subcomplexes that are informative of its quaternary structure. The unfolding of the precursor and the percentages of the distinct products suggest that the dissociation pathways vary for different charge states. The precursors at lower charge states (+21 for PHB dimer and +27 for GDH hexamer) produce a higher percentage of folded fragments and dissociate more symmetrically than the precusors at higher charge states (+29 for PHB dimer and +39 for GDH hexamer). The precursors at lower charge state may be more native-like than the higher charge state because a higher percentage of folded fragments and a lower percentage of highly charged unfolded fragments are detected. The combination of SID and charge reduction is shown to be a powerful tool for quaternary structure analysis of refractory noncovalent protein complexes, as illustrated by the data for PHB dimer and GDH hexamer.

  17. Acute and Chronic Dissociation and Somatized Anxiety as Related to Childhood Sexual Abuse.

    Science.gov (United States)

    Maynes, Lynn C.; Feinauer, Leslie L.

    1994-01-01

    Examined relationship between effects of four sexual abuse variables (identity of perpetrator, frequency of abuse, duration of abuse experiences, and severity of sexual abuse) and survivor symptomatology of acute dissociation, chronic dissociation, and somatized anxiety. Data from 226 respondents showed that severity of sexual abuse experience was…

  18. Assessment of dissociation in Bosnian treatment-seeking refugees in Denmark

    DEFF Research Database (Denmark)

    Palic, Sabina; Carlsson, Jessica; Armour, Cherie

    2015-01-01

    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...

  19. Cognitive Processes, Trauma, and Dissociation--Misconceptions and Misrepresentations: Reply to Bremner (2010)

    Science.gov (United States)

    Giesbrecht, Timo; Lynn, Steven J.; Lilienfeld, Scott O.; Merckelbach, Harald

    2010-01-01

    In a recent review (Giesbrecht, Lynn, Lilienfeld, & Merckelbach, 2008), we critically evaluated the research literature on cognitive processes in dissociation. In a comment, Bremner (2010) has voiced reservations about our contention that evidence for the causal role of trauma in dissociation is limited. In this reply, we argue that Bremner's…

  20. Dissociation in the phenomenological perspective (in athletes and representatives of extreme careers

    Directory of Open Access Journals (Sweden)

    Anastasia S. Vlasik

    2015-09-01

    Full Text Available This paper attempts to analyze dissociation from the perspective of phenomenology as experience of persons engaged in activities related to high stress (physical and/ or psychological. Dissociation is usually correlated with the so-called reaction fading in life-threatening situations, which along with the reactions of “fight or flight” reveal both in humans and the representatives of the animal world (“fight, flight or freeze”. However, unlike animals humans are often able to act purposefully in dissociative states, or randomly enter them. Specific features and diversity of manifestations of dissociation in humans are determined by the linguistic nature of human consciousness, which is logical to appeal to the philosophers of the phenomenological direction within which consciousness is the subject matter of their research. Based on the concept of Henri Bergson and Gilles Deleuze various manifestations of dissociation are detected: from the grave symptoms of PTSD (the so-called invasion of symptoms to controlled arbitrarily selected dissociative strategies for athletes. Dissociative experiences by experts of extreme careers are considered: law enforcement officers who participated in missions in «hot spots», and EMERCOM psychologists. Dissociation mechanism in terms of phenomenology is defined. The development and application of adequate diagnostic tools, psychological work with the athletes to regulate the focus of attention during the competition is supposed to contribute to the achievement of a high sports results.

  1. Differential dissociation micromethod for the investigation of binding of metandrostenolone (Nerobol) to plasma proteins

    International Nuclear Information System (INIS)

    Bojadzsieva, Milka; Kocsar, Laszlo; Kremmer, Tibor

    1985-01-01

    A micromethod was developed to determine the binding of anabolic streoids to plasma proteins. The new procedure combines precipitation with ammonium sulphate and differential dissociation. The binding parameters (association constant, specific binding capacity) are calculated on the basis of dissociation curves of sup(3)H-metandrostenolone from the precipitated sexual binding globuline. (L.E.)

  2. Differential dissociation micromethod for the investigation of binding of metandrostenolone (Nerobol) to plasma proteins

    Energy Technology Data Exchange (ETDEWEB)

    Bojadzsieva, M.; Kocsar, L. (Orszagos Frederic Joliot-Curie Sugarbiologiai es Sugaregeszseguegyi Kutato Intezet, Budapest (Hungary)); Kremmer, T. (Orszagos Onkologiai Intezet, Budapest (Hungary))

    1985-01-01

    A micromethod was developed to determine the binding of anabolic steroids to plasma proteins. The new procedure combines precipitation with ammonium sulphate and differential dissociation. The binding parameters (association constant, specific binding capacity) are calculated on the basis of dissociation curves of sup(3)H-metandrostenolone from the precipitated sexual binding globuline.

  3. Dissociation constants of phosphoric acid in dimethylformamide-water mixtures at 298.15 K

    Science.gov (United States)

    Safonova, L. P.; Fadeeva, Yu. A.; Pryakhin, A. A.

    2009-10-01

    The dissociation constants of phosphoric acid (p K 1 and p K 2) in water-dimethylformamide (DMFA) mixtures (0-0.65 mole fractions of DMFA) were determined at 298.15 K by potentiometric titration. The extrapolation of these data to pure DMFA and the comparative calculation method were used to estimate the dissociation constants of the acid in DMFA.

  4. Child Sexual Abuse Survivors with Dissociative Amnesia: What's the Difference?

    Science.gov (United States)

    Wolf, Molly R.; Nochajski, Thomas H.

    2013-01-01

    Although the issue of dissociative amnesia in adult survivors of child sexual abuse has been contentious, many research studies have shown that there is a subset of child sexual abuse survivors who have forgotten their abuse and later remembered it. Child sexual abuse survivors with dissociative amnesia histories have different formative and…

  5. Reactive dissociative experiences in response to acute increases in shame feelings.

    Science.gov (United States)

    Dorahy, Martin J; McKendry, Hadyn; Scott, Amber; Yogeeswaran, Kumar; Martens, Andy; Hanna, Donncha

    2017-02-01

    Studies have not examined if a direct causal relationship exists between shame and dissociation. The current research examined whether increases in dissociation were evident following exposure to acute shame feelings induced via narrative scripts of shame-evoking situations. Following Gilbert's (1998) differentiation between external and internal shame, participants heard shame-inducing or emotionally neutral stories in conditions designed to heighten (1) external shame, (2) internal shame or (3) general shame. In study 1, using a student sample (N = 78), dissociation as measured by the Modified Peritraumatic Dissociation Questionnaire was elevated during the shame script compared to the neutral script regardless of the type of shame participants were exposed to. A strong correlation was found between trait shame and trait dissociation. In study 2, using a treatment-attending sample (N = 33) and assessing intrusions in the two days following the script exposure, participants again demonstrated an increase in acute dissociative experiences during the shame script compared to the neutral script regardless of the type of shame evoked. Intrusions were present for the shame narrative with the distress they caused related to acute (peri-experimental) dissociation. Elevations in shame feelings produced a reactive response in dissociative experiences, which may heighten the distress associated with shame-filled intrusions. Copyright © 2016. Published by Elsevier Ltd.

  6. Electron Transfer and Collision Induced Dissociation of Non-Derivatized and Derivatized Desmosine and Isodesmosine

    NARCIS (Netherlands)

    Ongay, Sara; Hermans, Jos; Bruins, Andries P.; Nieuwendijk, Adrianus M. C. H.; Overkleeft, Hermen; Bischoff, Rainer

    Electron transfer dissociation (ETD) has attracted increasing interest due to its complementarity to collision-induced dissociation (CID). ETD allows the direct localization of labile post-translational modifications, which is of main interest in proteomics where differences and similarities between

  7. Posttraumatic stress symptoms, dissociation, and alexithymia in an Italian sample of flood victims

    Directory of Open Access Journals (Sweden)

    Craparo G

    2014-11-01

    Full Text Available Giuseppe Craparo,1 Alessio Gori,2 Elvira Mazzola,1 Irene Petruccelli,1 Monica Pellerone,1 Giuseppe Rotondo3 1Faculty of Human and Social Sciences, Kore University of Enna, Enna, Italy; 2Department of Psychology, University of Florence, Florence, Italy; 3Department of Psychology, Unit of Psychotraumatology, San Raffaele Giglio Hospital of Cefalù, Cefalù, Italy Background: Several studies have demonstrated a significant association between dissociation and posttraumatic symptoms. A dissociative reaction during a traumatic event may seem to predict the later development of posttraumatic stress symptoms. Moreover, several researchers also observed an alexithymic condition in a variety of traumatized samples.Methods: A total of 287 flood victims (men =159, 55.4%; women =128, 44.6% with an age range of 17–21 years (mean =18.33; standard deviation =0.68 completed the following: Impact of Event Scale–Revised, Dissociative Experiences Scale II, Twenty-Item Toronto Alexithymia Scale, and Peritraumatic Dissociative Experiences Questionnaire.Results: We found significant correlations among all variables. Linear regression showed that peritraumatic dissociation plays a mediator role between alexithymia, dissociation, and posttraumatic stress symptoms.Conclusion: Our results seem to confirm the significant roles of both dissociation and alexithymia for the development of posttraumatic symptoms. Keywords: peritraumatic dissociation, posttraumatic symptoms, PTSD

  8. Somatoform dissociation and traumatic experiences in patients with rheumatoid arthritis and fibromyalgia

    NARCIS (Netherlands)

    Näring, G.W.B.; Lankveld, W.G.J.M. van; Geenen, M.J.M.

    2007-01-01

    Objective: Trauma and dissociation tend to be interrelated. The objective of this study was to examine the frequency of traumatic experiences and somatoform dissociation in patients with Fibromyalgia syndrome (FMS) or rheumatoid arthritis (RA), two conditions that are both characterized by pain and

  9. Somatoform dissociation and traumatic experiences in patients with rheumatoid arthritis and fibromyalgia

    NARCIS (Netherlands)

    Näring, G.W.B.; Lankveld, W.G.J.M. van; Geenen, M.J.M.

    2007-01-01

    OBJECTIVE: Trauma and dissociation tend to be interrelated. The objective of this study was to examine the frequency of traumatic experiences and somatoform dissociation in patients with fibromyalgia syndrome (FMS) or rheumatoid arthritis (RA), two conditions that are both characterized by pain and

  10. Dissociative subtype of DSM-5 posttraumatic stress disorder in U.S. veterans.

    Science.gov (United States)

    Tsai, Jack; Armour, Cherie; Southwick, Steven M; Pietrzak, Robert H

    2015-01-01

    The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) formally introduced a dissociative subtype of posttraumatic stress disorder (PTSD). This study examined the proportion of U.S. veterans with DSM-5 PTSD that report dissociative symptoms; and compared veterans with PTSD with and without the dissociative subtype and trauma-exposed controls on sociodemographics, clinical characteristics, and quality of life. Multivariable analyses were conducted on a nationally representative sample of 1484 veterans from the National Health and Resilience in Veterans Study (second baseline survey conducted September-October, 2013). Of the 12.0% and 5.2% of veterans who screened positive for lifetime and past-month DSM-5 PTSD, 19.2% and 16.1% screened positive for the dissociative subtype, respectively. Among veterans with PTSD, those with the dissociative subtype reported more severe PTSD symptoms, comorbid depressive and anxiety symptoms, alcohol use problems, and hostility than those without the dissociative subtype. Adjusting for PTSD symptom severity, those with the dissociative subtype continued to report more depression and alcohol use problems. These results underscore the importance of assessing, monitoring, and treating the considerable proportion of veterans with PTSD and dissociative symptoms. Published by Elsevier Ltd.

  11. A Genetic Analysis of Individual Differences in Dissociative Behaviors in Childhood and Adolescence

    Science.gov (United States)

    Becker-Blease, Kathryn A.; Deater-Deckard, Kirby; Eley, Thalia; Freyd, Jennifer J.; Stevenson, Jim; Plomin, Robert

    2004-01-01

    Background: Dissociation--a pattern of general disruption in memory and consciousness--has been found to be an important cognitive component of children's and adults' coping with severe trauma. Dissociative experiences include amnesia, identity disturbance, age regression, difficulty with concentration, and trance states. Stable individual…

  12. 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.

  13. Reach tracking reveals dissociable processes underlying cognitive control.

    Science.gov (United States)

    Erb, Christopher D; Moher, Jeff; Sobel, David M; Song, Joo-Hyun

    2016-07-01

    The current study uses reach tracking to investigate how cognitive control is implemented during online performance of the Stroop task (Experiment 1) and the Eriksen flanker task (Experiment 2). We demonstrate that two of the measures afforded by reach tracking, initiation time and reach curvature, capture distinct patterns of effects that have been linked to dissociable processes underlying cognitive control in electrophysiology and functional neuroimaging research. Our results suggest that initiation time reflects a response threshold adjustment process involving the inhibition of motor output, while reach curvature reflects the degree of co-activation between response alternatives registered by a monitoring process over the course of a trial. In addition to shedding new light on fundamental questions concerning how these processes contribute to the cognitive control of behavior, these results present a framework for future research to investigate how these processes function across different tasks, develop across the lifespan, and differ among individuals. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Front-End Electron Transfer Dissociation: A New Ionization Source

    Science.gov (United States)

    Earley, Lee; Anderson, Lissa C.; Bai, Dina L.; Mullen, Christopher; Syka, John E. P.; English, A. Michelle; Dunyach, Jean-Jacques; Stafford, George C.; Shabanowitz, Jeffrey; Hunt, Donald F.; Compton, Philip D.

    2013-01-01

    Electron transfer dissociation (ETD), a technique that provides efficient fragmentation while depositing little energy into vibrational modes, has been widely integrated into proteomics workflows. Current implementations of this technique, as well as other ion–ion reactions like proton transfer, involve sophisticated hardware, lack robustness, and place severe design limitations on the instruments to which they are attached. Described herein is a novel, electrical discharge-based reagent ion source that is located in the first differentially pumped region of the mass spectrometer. The reagent source was found to produce intense reagent ion signals over extended periods of time while having no measurable impact on precursor ion signal. Further, the source is simple to construct and enables implementation of ETD on any instrument without modification to footprint. Finally, in the context of hybrid mass spectrometers, relocation of the reagent ion source to the front of the mass spectrometer enables new approaches to gas phase interrogation of intact proteins. PMID:23909443

  15. The HD+ dissociative recombination rate coefficient at low temperature

    Directory of Open Access Journals (Sweden)

    Wolf A.

    2015-01-01

    Full Text Available The effect of the rotational temperature of the ions is considered for low-energy dissociative recombination (DR of HD+. Merged beams measurements with HD+ ions of a rotational temperature near 300 K are compared to multichannel quantum defect theory calculations. The thermal DR rate coefficient for a Maxwellian electron velocity distribution is derived from the merged-beams data and compared to theoretical results for a range of rotational temperatures. Good agreement is found for the theory with 300 K rotational temperature. For a low-temperature plasma environment where also the rotational temperature assumes 10 K, theory predicts a considerably higher thermal DR rate coefficient. The origin of this is traced to predicted resonant structures of the collision-energy dependent DR cross section at few-meV collision energies for the particular case of HD+ ions in the rotational ground state.

  16. 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.

  17. Characterization of Neutral Radicals from a Dissociative Electron Attachment Process

    Science.gov (United States)

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

    2017-08-01

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

  18. A dissociative electron attachment cross-section estimator

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  19. Dissociative recombination in reactive flows related to planetary atmospheric entries

    Directory of Open Access Journals (Sweden)

    Bultel Arnaud

    2015-01-01

    Full Text Available The Dissociative Recombination (DR processes play a significant role in plasma chemistry. This article illustrates this role from the modeling point of view in the case of reactive flows related to atmospheric entry plasmas. Two situations are investigated, for which the studied plasma is nitrogen. The first configuration corresponds to the relaxation process behind a strong shock wave moving at high Mach number in a shock tube, the second one to the recombination taking place in an expanding plasma flowing in a diverging nozzle. In both cases, the collisional-radiative model CoRaM-N2, involving N2, N, N2+, N+ and electrons, is implemented in an Eulerian 1D code able to compute the aerodynamic fields; calculations are performed in standard conditions. We show that, according to the rate coefficients used for the DR processes, the population density of the charged species especially N2+ is strongly modified only for the post-shock flow.

  20. Selective interference reveals dissociation between memory for location and colour.

    Science.gov (United States)

    Vuontela, V; Rämä, P; Raninen, A; Aronen, H J; Carlson, S

    1999-08-02

    The aim was to study whether there is indication of a dissociation in processing of visuospatial and colour information in working memory in humans. Experimental subjects performed visuospatial and colour n-back tasks with and without visuospatial and colour distractive stimuli presented in the middle of the delay period to specifically affect mnemonic processing of task-related information. In the high memory-load condition, the visuospatial, but not the colour, task was selectively disrupted by visuospatial but not colour distractors. When subvocal rehearsal of the memoranda in the colour task was prevented by articulatory suppression; colour task performance was also selectively disrupted by distractors qualitatively similar to the memoranda. The results support the suggestion that visual working memory for location is processed separate from that for colour.

  1. Rotational State Effects in the Dissociative Recombination of H2+

    Science.gov (United States)

    Zhaunerchyk, V.; Al-Khalili, A.; Thomas, R. D.; Geppert, W. D.; Bednarska, V.; Petrignani, A.; Ehlerding, A.; Hamberg, M.; Larsson, M.; Rosen, S.; van der Zande, W. J.

    2007-07-01

    We have studied the dissociative recombination (DR) of molecular hydrogen ions with slow electrons over a range of collision energies from 0 to 400 meV. By employing a pulsed expansion source for rotational cooling and by exploiting superelastic collisions with near-0-eV electrons in a heavy ion storage ring for vibrational cooling, we observe a highly structured DR cross section, comparable to that reported for HD+. Using para-hydrogen-enriched ion beams, we identify for the first time features in the DR cross sections attributed to ν=0, J=even molecules (para-H2) and ν=0, J=odd (ortho-H2) molecules, separately. Indications are given that para levels have different DR rate coefficients from ortho levels for the first four vibrational levels at near-0-eV collisions.

  2. Semiclassical Calculation of Reaction Rate Constants for Homolytical Dissociations

    Science.gov (United States)

    Cardelino, Beatriz H.

    2002-01-01

    There is growing interest in extending organometallic chemical vapor deposition (OMCVD) to III-V materials that exhibit large thermal decomposition at their optimum growth temperature, such as indium nitride. The group III nitrides are candidate materials for light-emitting diodes and semiconductor lasers operating into the blue and ultraviolet regions. To overcome decomposition of the deposited compound, the reaction must be conducted at high pressures, which causes problems of uniformity. Microgravity may provide the venue for maintaining conditions of laminar flow under high pressure. Since the selection of optimized parameters becomes crucial when performing experiments in microgravity, efforts are presently geared to the development of computational OMCVD models that will couple the reactor fluid dynamics with its chemical kinetics. In the present study, we developed a method to calculate reaction rate constants for the homolytic dissociation of III-V compounds for modeling OMCVD. The method is validated by comparing calculations with experimental reaction rate constants.

  3. 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.

  4. A theoretical approach to low multiplicity diffractive dissociation

    International Nuclear Information System (INIS)

    Bishari, M.

    1977-01-01

    The dynamics of low mass inelastic diffractive production in the framework of the ''1/N dual unitarization'' scheme are investigated. The smallness of inelastic diffractive dissociation is explicitly demonstrated by incorporating a Deck type mechanism with the crucial planar bootstrap equation. Although both inelastic and elastic pomeron couplings are of the same order in 1/N, the origin for their smallness is not identical. The work further confirms the validity of the iterative procedure, where the elastic amplitude is first generated from only non-diffractive intermediate states (except possibly for central collisions). Using a previous study of the ''Cylinder'' strength, a semi-quantitative results for the integrated cross-section for low multiplicity diffractive production is also presented, and is compared with the elastic cross-section at very high energies. (author)

  5. Dissociation energies of some high temperature molecules containing aluminum

    Science.gov (United States)

    Stearns, C. A.; Kohl, F. J.

    1972-01-01

    The Knudsen cell mass spectrometric method has been used to investigate the gaseous molecules Al2, AlSi,AlSiO, AlC2, Al2C2, and AlAuC2. Special attention was given to the experimental considerations and techniques needed to identify and to measure ion intensities for very low abundance molecular species. Second- and third-law procedures were used to obtain reaction enthalpies for pressure calibration independent and isomolecular exchange reactions. Dissociation energies for the molecules were derived from the measured ion intensities, free-energy functions obtained from estimated molecular constants, and auxiliary thermodynamic data. The bonding and stability of these aluminum containing molecules are compared with other similar species.

  6. Dissociating intuitive physics from intuitive psychology: Evidence from Williams syndrome.

    Science.gov (United States)

    Kamps, Frederik S; Julian, Joshua B; Battaglia, Peter; Landau, Barbara; Kanwisher, Nancy; Dilks, Daniel D

    2017-11-01

    Prior work suggests that our understanding of how things work ("intuitive physics") and how people work ("intuitive psychology") are distinct domains of human cognition. Here we directly test the dissociability of these two domains by investigating knowledge of intuitive physics and intuitive psychology in adults with Williams syndrome (WS) - a genetic developmental disorder characterized by severely impaired spatial cognition, but relatively spared social cognition. WS adults and mental-age matched (MA) controls completed an intuitive physics task and an intuitive psychology task. If intuitive physics is a distinct domain (from intuitive psychology), then we should observe differential impairment on the physics task for individuals with WS compared to MA controls. Indeed, adults with WS performed significantly worse on the intuitive physics than the intuitive psychology task, relative to controls. These results support the hypothesis that knowledge of the physical world can be disrupted independently from knowledge of the social world. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Dissociative fugue: Recurrent episodes in a young adult

    Directory of Open Access Journals (Sweden)

    Chintan Madhusudan Raval

    2015-01-01

    Full Text Available Dissociative fugue is a rare disorder which has been described as sudden, unexpected, travel away from home or one′s customary place of daily activities, with the inability to recall some or all of one′s past. There is no systematic data existing on it and very few cases reported in the literature. Here we report a case of fugue in a young adult male who travelled 8 times away from his home during last 1΍ year. He has a loss of memory for episodes with patchy recall of few events. Longest duration of fugue episode was of 1-month. The case describes mode of presentation to hospital and treatment given to restore his identity and reunite him in society and family.

  8. Focusing on dissociated motor development in Brazilian children

    Directory of Open Access Journals (Sweden)

    Minami Maria Avanise Yumi

    2001-01-01

    Full Text Available Dissociated motor development (DMD is considered when the baby starts independent walking late, with normality of the other fields of development. There is evidence that babies with DMD present an atypical crawling pattern and hypotonia. To investigate the frequency and characteristics of DMD, neurological examination was performed monthly in 177 healthy full-term babies from 6 months age, in urban and rural zone samples in Brazil. Among 20 children with atypical crawling, none presented hypotonia neither did they start independent walking late. The means of the ages at the begining of atypical crawling and independent walking acquisitions, 7.40mo (SD 1.4 and 12.76mo (SD 2.5 respectively, did not differ from the group with crossed crawling pattern. Thus, in this sample of Brazilian healthy children we did not find cases with DMD.

  9. The Importance of the Dissociation Rate in Ion Channel Blocking

    Directory of Open Access Journals (Sweden)

    Hugo Zeberg

    2018-02-01

    Full Text Available Understanding the relationships between the rates and dynamics of current wave forms under voltage clamp conditions is essential for understanding phenomena such as state-dependence and use-dependence, which are fundamental for the action of drugs used as anti-epileptics, anti-arrhythmics, and anesthetics. In the present study, we mathematically analyze models of blocking mechanisms. In previous experimental studies of potassium channels we have shown that the effect of local anesthetics can be explained by binding to channels in the open state. We therefore here examine models that describe the effect of a blocking drug that binds to a non-inactivating channel in its open state. Such binding induces an inactivation-like current decay at higher potential steps. The amplitude of the induced peak depends on voltage and concentration of blocking drug. In the present study, using analytical methods, we (i derive a criterion for the existence of a peak in the open probability time evolution for a model with an arbitrary number of closed states, (ii derive formula for the relative height of the peak amplitude, and (iii determine the voltage dependence of the relative peak height. Two findings are apparent: (1 the dissociation (unbinding rate constant is important for the existence of a peak in the current waveform, while the association (binding rate constant is not, and (2 for a peak to exist it suffices that the dissociation rate must be smaller than the absolute value of all eigenvalues to the kinetic matrix describing the model.

  10. Radiosensitivity of dissociated male germ cells in vitro

    International Nuclear Information System (INIS)

    Kobayashi, Jindo

    1980-01-01

    The meiotic and redifferentiating activities of dissociated testicular cells were used as the criteria for the injurious effect of 3 H-TdR on spermatogenic cells in vivo. 3 H-TdR was given intraperitoneally to 10-day-old dd mice at dose of 100 μCi/10 g for 30 min to 24 hr. The testes from normal and 3 H-TdR-treated mice were mechanically dissected and tripsinized in calcium- and magnesium-free balanced salt solution. After several times of washing, the cells were collected and cultured in the plastic dishes. About 4 x 10 6 dissociated cells were seeded in each dish. Two to 6 days after the cultivation, the cells in the static state were stained with Giemsa, and those in the floating state were stained with aceto-dahlia. Some of the testicular cells in the static state formed the aggregates consisting mainly of spermatogoneal cells. The aggregate formation observed 1 day after the culture began to decrease sharply with the increase in the dose of 3 H-TdR used, but that observed later (3rd and 6th day) decreased gradually. It is considered that this was due to the recovery from injury during the prolonged culture. The frequency of meiotic cells in the floating cells was 0.5 to 1.0% in the control during the first 24 hr. The dose response curve for meiosis determined 1, 5 and 7 days after the incubation following the treatment with 100 μCi/10 g 3 H-TdR for 3 - 24 hr, consists of dose-sensitive and -insensitive phases. In the control, about 2% of the spermatocytic cells in the floating cells in vitro were polynucleic cells, the number increasing after 3 H-TdR treatment. These results suggest that the effect of 3 H-TdR on cell division differs from that on cell differentiation. (Kaihara, S.)

  11. Obesity and dissociable forms of impulsivity in young adults.

    Science.gov (United States)

    Chamberlain, Samuel R; Derbyshire, Katherine L; Leppink, Eric; Grant, Jon E

    2015-10-01

    Obesity is one of the leading causes of preventable morbidity and mortality, and young people are increasingly affected. The aim of this study was to examine relationships between obesity and dissociable forms of impulsivity in young adults. A group of young adults (511) was recruited from city areas in the United States using media advertisements. These young adults were administered careful and extensive clinical and neurocognitive assessment in order to quantify different aspects of impulsivity (behavioral/phenomenological-, cognitive-, and personality-related measures). Associations between obesity and impulsivity were explored using multivariate analysis of variance and discriminant function analysis. 10.8% of the sample was obese, and 21.5% was overweight. Compared to controls, subjects with obesity showed significantly elevated rates of maladaptive gambling behaviors, monetary amounts lost to gambling, nicotine consumption, impulsive action (prolonged stop-signal reaction times in the Stop-Signal Test), and impulsive decision-making (reduced modulation of behavior as a function of risk in the Cambridge Gamble Test). Even accounting for potential confounding variables, obesity was significantly predicted by female gender, older age, more maladaptive gambling behaviors, and worse inhibitory control (stop-signal reaction times). Obesity is associated with several dissociable forms of impulsivity in young people, especially gambling and impulse dyscontrol. Family doctors should screen for gambling problems in obese young adults. Successful treatment of nicotine dependence in young obese people is likely to require intensive weight management support. Neuropsychological deficits relating to impulsivity occur in obese people in early adulthood, and may represent vulnerability markers rather than being due to chronic untoward metabolic effects on brain function.

  12. Dysfunctional schema modes, childhood trauma and dissociation in borderline personality disorder.

    Science.gov (United States)

    Johnston, Craig; Dorahy, Martin J; Courtney, Deyra; Bayles, Terry; O'Kane, Maria

    2009-06-01

    To examine the relationship between dysfunctional schema modes, childhood trauma and dissociation in borderline personality disorder (BPD). 30 BPD patients completed the Wessex Dissociation Scale (WDS), Childhood Trauma Questionnaire (CTQ), General Health Questionnaire (GHQ), and Schema Mode Questionnaire (SMQ). The 'Angry and Impulsive Child' and 'Abandoned and Abused Child' modes uniquely predicted dissociation scores. Childhood trauma did not predict dissociation scores. Findings support the schema mode model of BPD [Young, J. E., Klosko, J. S., & Weishaar, M. E. (2003). Schema therapy: A practitioners guide. London: Guilford Press] and its emphasis on the role of dissociation. Clinically they support the emphasis on the identification and integration of dysfunctional parts of the personality in working with individuals diagnosed with BPD.

  13. Dissociative experiences and quality of life in patients with non-epileptic attack disorder.

    Science.gov (United States)

    Mitchell, James W; Ali, Fizzah; Cavanna, Andrea E

    2012-11-01

    Dissociative experiences are commonly reported by patients with non-epileptic attack disorder (NEAD). This cross-sectional study examined the prevalence and characteristics of dissociative experiences in patients with NEAD and assessed their association with health-related quality of life (HRQoL). Fifty-three patients diagnosed with NEAD were consecutively recruited (70.0% female, mean age=42 years, 22.0% with comorbid epilepsy) from a specialist neuropsychiatric clinic. Our sample reported high levels of dissociative experiences, with 36.7% of patients scoring ≥30 on the Dissociative Experiences Scale (DES). Significant negative correlations were found between total DES scores and HRQoL, as measured by the QOLIE-31 questionnaire (r=-0.64, pdissociative experiences in this patient population, highlighting the importance of routinely screening patients for dissociative symptoms and their impact on patients' lives. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Gas hydrate dissociation off Svalbard induced by isostatic rebound rather than global warming.

    Science.gov (United States)

    Wallmann, Klaus; Riedel, M; Hong, W L; Patton, H; Hubbard, A; Pape, T; Hsu, C W; Schmidt, C; Johnson, J E; Torres, M E; Andreassen, K; Berndt, C; Bohrmann, G

    2018-01-08

    Methane seepage from the upper continental slopes of Western Svalbard has previously been attributed to gas hydrate dissociation induced by anthropogenic warming of ambient bottom waters. Here we show that sediment cores drilled off Prins Karls Foreland contain freshwater from dissociating hydrates. However, our modeling indicates that the observed pore water freshening began around 8 ka BP when the rate of isostatic uplift outpaced eustatic sea-level rise. The resultant local shallowing and lowering of hydrostatic pressure forced gas hydrate dissociation and dissolved chloride depletions consistent with our geochemical analysis. Hence, we propose that hydrate dissociation was triggered by postglacial isostatic rebound rather than anthropogenic warming. Furthermore, we show that methane fluxes from dissociating hydrates were considerably smaller than present methane seepage rates implying that gas hydrates were not a major source of methane to the oceans, but rather acted as a dynamic seal, regulating methane release from deep geological reservoirs.

  15. 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

  16. Influence of cell dissociation procedures on the tumorigenicity of Simian Virus 40 transformed fibroblasts

    International Nuclear Information System (INIS)

    Tenforde, T.S.; Risius, J.; Beckmann, A.; Tobias, C.A.; Gurney, E.

    1975-11-01

    Mouse fibroblasts transformed by Simian Virus 40 (SV40) were examined for tumor forming ability in syngeneic BALB/c mice following dissociation from tissue culture dishes by two procedures. A significantly greater in vivo proliferative capacity was observed for cells dissociated by the tryspin-EDTA procedure, with the injected cell dose for tumor production in 50 percent of recipient mice (the TPD 50 ) being 16-fold lower than the TPD 50 for cells dissociated by the EDTA procedure. Host immunosuppression with 300 rad whole-body γ irradiation led to a significant 7-fold decrease in the TPD 50 for cells dissociated by the EDTA procedure, while no significant decrease in TPD 50 was observed for cells dissociated by the tryspin-EDTA procedure

  17. Daily stress interacts with trait dissociation to predict sleep-related experiences in young adults.

    Science.gov (United States)

    Soffer-Dudek, Nirit; Shahar, Golan

    2011-08-01

    Building on the previously documented effects of stress and dissociation on sleep and dreaming, we examined their interactive role in general sleep-related experiences (GSEs; e.g., nightmares, falling dreams, hypnagogic hallucinations; see Watson, 2001). Stress, sleep quality, and GSEs were assessed daily for 14 days among young adults. Baseline assessment included life stress, sleep quality, psychopathology, dissociation, and related dimensions. Multilevel analyses indicated that daily stress brings about GSEs among highly dissociative young adults. Additionally, baseline trait dissociation predicted within-subject elevation in GSEs when daily stress was high. Flawed sleep-wake transitions, previously linked to dissociation and sleep-related experiences, might account for this effect. © 2011 American Psychological Association

  18. Dissociation of mono- and co-culture spheroids into single cells for subsequent flow cytometric analysis.

    Science.gov (United States)

    Grässer, Ute; Bubel, Monika; Sossong, Daniela; Oberringer, Martin; Pohlemann, Tim; Metzger, Wolfgang

    2018-03-01

    Spheroids are considered to reflect the natural organization of cells better than 2D cell cultures, but their analysis by flow cytometry requires dissociation into single cells. We established protocols for dissociation of mono- and co-culture spheroids consisting of human fibroblasts and human endothelial cells. Cell recovery rate and viability after dissociation were evaluated with hemocytometer and by flow cytometry. The diameter of cells and the amount of cell aggregates were quantified by Casy ® -technology and the cellular composition was analyzed by flow cytometry. Optimal dissociation conditions with low cell aggregation were determined by size, cultivation time and cellular composition of the spheroids. Smaller spheroids (10,000 cells) could be dissociated with Accutase ® , whereas larger spheroids (50,000 cells) required more stringent dissociation conditions. The size of the cells decreased with increasing cultivation time. Cell recovery rate was dependent upon cellular composition and spheroid size. The highest cell recovery rate was found for co-culture spheroids. The highest cell viability was detected for dissociated fibroblast spheroids. A quantitative analysis of the cellular composition of dissociated co-culture spheroids was possible. Spheroids can be successfully dissociated into singular cells for subsequent flow cytometric analysis. Dissociation conditions as well as cell recovery rate and cell viability depend on size, cultivation time and cellular composition of the spheroids. The observed decrease in cell size in spheroids over time might be responsible for the well-known time-dependent decrease in spheroid size. Copyright © 2017 Elsevier GmbH. All rights reserved.

  19. Self-organisation after embryonic kidney dissociation is driven via selective adhesion of ureteric epithelial cells.

    Science.gov (United States)

    Lefevre, James G; Chiu, Han S; Combes, Alexander N; Vanslambrouck, Jessica M; Ju, Ali; Hamilton, Nicholas A; Little, Melissa H

    2017-03-15

    Human pluripotent stem cells, after directed differentiation in vitro , can spontaneously generate complex tissues via self-organisation of the component cells. Self-organisation can also reform embryonic organ structure after tissue disruption. It has previously been demonstrated that dissociated embryonic kidneys can recreate component epithelial and mesenchymal relationships sufficient to allow continued kidney morphogenesis. Here, we investigate the timing and underlying mechanisms driving self-organisation after dissociation of the embryonic kidney using time-lapse imaging, high-resolution confocal analyses and mathematical modelling. Organotypic self-organisation sufficient for nephron initiation was observed within a 24 h period. This involved cell movement, with structure emerging after the clustering of ureteric epithelial cells, a process consistent with models of random cell movement with preferential cell adhesion. Ureteric epithelialisation rapidly followed the formation of ureteric cell clusters with the reformation of nephron-forming niches representing a later event. Disruption of P-cadherin interactions was seen to impair this ureteric epithelial cell clustering without affecting epithelial maturation. This understanding could facilitate improved regulation of patterning within organoids and facilitate kidney engineering approaches guided by cell-cell self-organisation. © 2017. Published by The Company of Biologists Ltd.

  20. Schema modes and dissociation in borderline personality disorder/traits in adolescents or young adults.

    Science.gov (United States)

    Barazandeh, Hoda; Kissane, David W; Saeedi, Naysun; Gordon, Michael

    2018-03-01

    Dramatic mental shifts in young patients with borderline personality disorder (BPD) can be understood to occur via dissociative processes found in immature schema modes. A schema mode is an organized pattern of thought, affect and behaviour based on a set of core beliefs. These maladaptive modes are not integrated into a united personality structure and can function in a dissociated form. The aim of this study was to empirically assess the relationship between dysfunctional schema modes and dissociation in BPD. Forty-two young patients with BPD confirmed by the structured clinical interview for DSM-IV Axis-II personality disorders (SCID-II) were further assessed by the Psychiatric Diagnostic Screening Questionnaire (PDSQ), DSM-IV/ICD-10 Personality Questionnaire (DIP-Q), Schema Mode Inventory (SMI) and Wessex Dissociation Scale (WDS). Pearson correlations assessed associations and stepwise regression explored the extent of these associations. The strongest correlations were found between dissociation and the following modes: Detached Protector, Angry Child, Impulsive Child, Punitive Parent, Demanding Parent, and Vulnerable Child. Stepwise regression analysis indicated that schema modes explained 58% of the variance in dissociation. The schema modes that significantly predicted dissociation were the Detached Protector and Impulsive Child modes. Key therapeutic targets in treating adolescents with BPD include detachment and impulsivity. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Relationships among Childhood Trauma, Posttraumatic Stress Disorder and Dissociation in Men Living with HIV/AIDS

    Science.gov (United States)

    Kamen, Charles; Bergstrom, Jessica; Koopman, Cheryl; Lee, Susanne; Gore-Felton, Cheryl

    2012-01-01

    This study examined the relationships among dissociation, childhood trauma and sexual abuse, and posttraumatic stress disorder (PTSD) symptoms in HIV-positive men. Data was collected from 167 men enrolled in a randomized clinical trial (Project RISE) that examined a group therapy intervention to decrease HIV-related risk behavior and trauma-related stress symptoms. Participants completed the Trauma History Questionnaire, the Impact of Event Scale - Revised, and the Stanford Acute Stress Reaction Questionnaire. Overall, 35.3% of the participants reported having experienced childhood sexual abuse (CSA). A total of 55.7% of the sample met diagnostic criteria for PTSD. The intensity of dissociative symptoms that participants endorsed was positively associated with experience of childhood sexual abuse (r = .20, p Dissociative symptoms were also positively associated with specific PTSD symptoms, notably hyperarousal (r = .69, p dissociation than childhood sexual abuse. These results suggest that childhood sexual abuse may be involved in the development of dissociative symptoms in the context of adulthood stress reactions. Furthermore, the pattern of the association between dissociation and PTSD is consistent with the possibility of a dissociative PTSD subtype among HIV-positive men. PMID:22211444

  2. Cumulative childhood trauma, emotion regulation, dissociation, and behavior problems in school-aged sexual abuse victims.

    Science.gov (United States)

    Hébert, Martine; Langevin, Rachel; Oussaïd, Essaïd

    2018-01-01

    Child sexual abuse is associated with a plethora of devastating repercussions. A significant number of sexually abused children are likely to experience other forms of maltreatment that can seriously affect their emotion regulation abilities and impede on their development. The aim of the study was to test emotion regulation and dissociation as mediators in the association between cumulative childhood trauma and internalized and externalized behavior problems in child victims of sexual abuse. Participants were 309 sexually abused children (203 girls and 106 boys; Mean age = 9.07) and their non-offending parent. Medical and clinical files were coded for cumulative childhood trauma. At initial evaluation (T1), parents completed measures assessing children's emotion regulation abilities and dissociation. At Time 2 (T2), parents completed a measure assessing children's behavior problems. Mediation analyses were conducted with emotion regulation and dissociation as sequential mediators using Mplus software. Findings revealed that cumulative childhood trauma affects both internalized and externalized behavior problems through three mediation paths: emotion regulation alone, dissociation alone, and through a path combining emotion regulation and dissociation. Both emotion regulation and dissociation were assessed at T1 and thus the temporal sequencing of mediators remains to be ascertained through a longitudinal design. All measures were completed by the parents. Clinicians should routinely screen for other childhood trauma in vulnerable clienteles. In order to tackle behavior problems, clinical interventions for sexually abused youth need to address emotion regulation competencies and dissociation. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Gene expression profiles in relation to tension and dissociation in borderline personality disorder.

    Directory of Open Access Journals (Sweden)

    Christian Schmahl

    Full Text Available The biological underpinnings of borderline personality disorder (BPD and its psychopathology including states of aversive tension and dissociation is poorly understood. Our goal was to examine transcriptional changes associated with states of tension or dissociation within individual patients in a pilot study. Dissociation is not only a critical symptom of BPD but has also been associated with higher risk for self-mutilation and depression. We conducted a whole blood gene expression profile analysis using quantitative PCR in 31 female inpatients with BPD. For each individual, two samples were drawn during a state of high tension and dissociation, while two samples were drawn at non-tension states. There was no association between gene expression and tension states. However, we could show that Interleukin-6 was positively correlated to dissociation scores, whereas Guanine nucleotide-binding protein G(s subunit alpha isoforms, Mitogen-activated protein kinase 3 and 8, Guanine nucleotide-binding protein G(i subunit alpha-2, Beta-arrestin-1 and 2, and Cyclic AMP-responsive element-binding protein were negatively correlated to dissociation. Our data point to a potential association of dissociation levels with the expression of genes involved in immune system regulation as well as cellular signalling/second-messenger systems. Major limitations of the study are the the possibly heterogeneous cell proportions in whole blood and the heterogeneous medication.

  4. When dreams become a royal road to confusion: realistic dreams, dissociation, and fantasy proneness.

    Science.gov (United States)

    Rassin, E; Merckelbach, H; Spaan, V

    2001-07-01

    Scientific discussions about false memories have, so far, mainly focused on external determinants (e.g., therapeutic interventions). However, in some cases, false memories might develop more spontaneously. For example, difficulties in distinguishing between dreams and reality may lead to false memories. The present article discusses two studies (N = 85 and 255, respectively) that examined to what extent such difficulties occur. In both studies, a nontrivial minority of respondents (11.8% and 25.9%, respectively) reported that they had had the experience of not being able to discriminate between dream and reality. As expected, respondents who reported this type of confusion scored higher on fantasy proneness and dissociation measures than respondents who did not report this confusion.

  5. People reporting experiences of mediumship have higher dissociation symptom scores than non-mediums, but below thresholds for pathological dissociation [version 3; referees: 2 approved, 1 not approved

    Directory of Open Access Journals (Sweden)

    Helané Wahbeh

    2018-01-01

    Full Text Available Background: Dissociative states exist on a continuum from nonpathological forms, such as highway hypnosis and day-dreaming, to pathological states of derealization and depersonalization. Claims of communication with deceased individuals, known as mediumship, were once regarded as a pathological form of dissociation, but current definitions recognize the continuum and include distress and functional disability as symptoms of pathology. This study examined the relationship between dissociative symptoms and mediumship in a large convenience sample. Methods: Secondary analyses of cross-sectional survey data were conducted. The survey included demographics, the Dissociation Experience Scale Taxon (DES-T, score range 0-100, as well as questions about instances of mediumship experiences. Summary statistics and linear and logistic regressions explored the relationship between dissociative symptoms and mediumship endorsement. Results: 3,023 participants were included and were mostly middle-aged (51 years ± 16; range 17-96, female (70%, Caucasian (85%, college educated (88%, had an annual income over $50,000 (55%, and were raised Christian (71% but were presently described as Spiritual but not Religious (60%. Mediumship experiences were endorsed by 42% of participants, the experiences usually began in childhood (81%, and 53% had family members who reported similar experiences. The mean DES-T score across all participants was 14.4 ± 17.3, with a mean of 18.2 ± 19.3 for those claiming mediumship experiences and 11.8 ± 15.2 for those who did not (t = -10.3, p < 0.0005. The DES-T threshold score for pathological dissociation is 30. Conclusions: On average, individuals claiming mediumship experiences had higher dissociation scores than non-claimants, but neither group exceeded the DES-T threshold for pathology. Future studies exploring dissociative differences between these groups may benefit from using more comprehensive measures of dissociative symptoms

  6. An eye for an I: a 35-year-old woman with fluctuating oculomotor deficits and dissociative identity disorder.

    Science.gov (United States)

    Bhuvaneswar, Chaya; Spiegel, David

    2013-01-01

    Physiologic changes, including neurological or pseudo-neurological symptoms, occur across identity states in dissociative identity disorder DID) and can be objectively measured. The idea that dissociative phenomena might be associated with changes in brain function is consistent with research on the brain effects of hypnosis. The authors report a case of psycho-physiologic differences among 4 alter personalities manifested by a 35-year-old woman with DID. Differences in visual acuity, frequency of pendular nystagmus, and handedness were observed in this patient both when the alter personalities appeared spontaneously and when elicited under hypnosis. The authors consider several diagnostic possibilities for these findings and discuss whether prevailing treatment recommendations for DID patients could possibly be modified to ameliorate such visual and neurologic symptoms.

  7. Radiosensitivity of dissociated male germ cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, J. (Utsunomiya Univ. (Japan). Faculty of Education)

    1980-12-01

    The meiotic and redifferentiating activities of dissociated testicular cells were used as the criteria for the injurious effect of /sup 3/H-TdR on spermatogenic cells in vivo. /sup 3/H-TdR was given intraperitoneally to 10-day-old dd mice at dose of 100 ..mu..Ci/10 g for 30 min to 24 hr. The testes from normal and /sup 3/H-TdR-treated mice were mechanically dissected and tripsinized in calcium- and magnesium-free balanced salt solution. After several times of washing, the cells were collected and cultured in the plastic dishes. About 4 x 10/sup 6/ dissociated cells were seeded in each dish. Two to 6 days after the cultivation, the cells in the static state were stained with Giemsa, and those in the floating state were stained with aceto-dahlia. Some of the testicular cells in the static state formed the aggregates consisting mainly of spermatogoneal cells. The aggregate formation observed 1 day after the culture began to decrease sharply with the increase in the dose of /sup 3/H-TdR used, but that observed later (3rd and 6th day) decreased gradually. It is considered that this was due to the recovery from injury during the prolonged culture. The frequency of meiotic cells in the floating cells was 0.5 to 1.0% in the control during the first 24 hr. The dose response curve for meiosis determined 1, 5 and 7 days after the incubation following the treatment with 100 ..mu..Ci/10 g /sup 3/H-TdR for 3 - 24 hr, consists of dose-sensitive and -insensitive phases. In the control, about 2% of the spermatocytic cells in the floating cells in vitro were polynucleic cells, the number increasing after /sup 3/H-TdR treatment. These results suggest that the effect of /sup 3/H-TdR on cell division differs from that on cell differentiation.

  8. Dissociation dynamics of diatomic molecules in intense fields

    Science.gov (United States)

    Magrakvelidze, Maia

    We study the dynamics of diatomic molecules (dimers) in intense IR and XUV laser fields theoretically and compare the results with measured data in collaboration with different experimental groups worldwide. The first three chapters of the thesis cover the introduction and the background on solving time-independent and time-dependent Schrodinger equation. The numerical results in this thesis are presented in four chapters, three of which are focused on diatomic molecules in IR fields. The last one concentrates on diatomic molecules in XUV pulses. The study of nuclear dynamics of H2 or D2 molecules in IR pulses is given in Chapter 4. First, we investigate the optimal laser parameters for observing field-induced bond softening and bond hardening in D2+. Next, the nuclear dynamics of H2 + molecular ions in intense laser fields are investigated by analyzing their fragment kinetic-energy release (KER) spectra as a function of the pump-probe delay τ Lastly, the electron localization is studied for long circularly polarized laser pulses. Chapter 5 covers the dissociation dynamics of O2+ in an IR laser field. The fragment KER spectra are analyzed as a function of the pump-probe delay τ Within the Born-Oppenheimer approximation, we calculate ab-initio adiabatic potential-energy curves and their electric dipole couplings, using the quantum chemistry code GAMESS. In Chapter 6, the dissociation dynamics of the noble gas dimer ions He 2+, Ne2+, Ar2 +, Kr2+, and Xe2 + is investigated in ultrashort pump and probe laser pulses of different wavelengths. We observe a striking "delay gap" in the pump-probe-delay-dependent KER spectrum only if the probe-pulse wavelength exceeds the pump-pulse wavelength. Comparing pump-probe-pulse-delay dependent KER spectra for different noble gas dimer cations, we quantitatively discuss quantum-mechanical versus classical aspects of the nuclear vibrational motion as a function of the nuclear mass. Chapter 7 focuses on diatomic molecules in XUV

  9. Dissociative states in dreams and brain chaos: Implications for creative awareness

    Directory of Open Access Journals (Sweden)

    Petr eBob

    2015-09-01

    Full Text Available This article reviews recent findings indicating some common brain processes during dissociative states and dreaming with the aim to outline a perspective that neural chaotic states during dreaming can be closely related to dissociative states that may manifest in dreams scenery. These data are in agreement with various clinical findings that dissociated states can be projected into the dream scenery in REM sleep periods and dreams may represent their specific interactions that may uncover unusual psychological potential of creativity in psychotherapy, art and scientific discoveries.

  10. Thermodynamic conversion process comporting a stage of chemical dissociation by radiolysis

    International Nuclear Information System (INIS)

    Gomberg, H.J.; Lewis, J.G.; Powers, J.E.

    1980-01-01

    Process for thermodynamic conversion by heating a working fluid at high pressure so that its temperature rises to a high figure, and extracting the heat from the working fluid at low pressure. The heating of the working fluid includes a first stage, of chemical dissociation of at least some of this fluid by radiolysis at a temperature under the thermal balance temperature of the dissociated fluid so that it is in a state of macroscopic thermal imbalance, and a second chemical reaction stage of the dissociated constituants of the working fluid so that they recombine with simultaneous heating of the working fluid [fr

  11. 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)

  12. Dissociative states in dreams and brain chaos: implications for creative awareness.

    Science.gov (United States)

    Bob, Petr; Louchakova, Olga

    2015-01-01

    This article reviews recent findings indicating some common brain processes during dissociative states and dreaming with the aim to outline a perspective that neural chaotic states during dreaming can be closely related to dissociative states that may manifest in dreams scenery. These data are in agreement with various clinical findings that dissociated states can be projected into the "dream scenery" in REM sleep periods and dreams may represent their specific interactions that may uncover unusual psychological potential of creativity in psychotherapy, art, and scientific discoveries.

  13. Dissociated multimodal hubs and seizures in temporal lobe epilepsy.

    Science.gov (United States)

    Douw, Linda; DeSalvo, Matthew N; Tanaka, Naoaki; Cole, Andrew J; Liu, Hesheng; Reinsberger, Claus; Stufflebeam, Steven M

    2015-04-01

    Brain connectivity at rest is altered in temporal lobe epilepsy (TLE), particularly in "hub" areas such as the posterior default mode network (DMN). Although both functional and anatomical connectivity are disturbed in TLE, the relationships between measures as well as to seizure frequency remain unclear. We aim to clarify these associations using connectivity measures specifically sensitive to hubs. Connectivity between 1000 cortical surface parcels was determined in 49 TLE patients and 23 controls with diffusion and resting-state functional magnetic resonance imaging. Two types of hub connectivity were investigated across multiple brain modules (the DMN, motor system, etcetera): (1) within-module connectivity (a measure of local importance that assesses a parcel's communication level within its own subnetwork) and (2) between-module connectivity (a measure that assesses connections across multiple modules). In TLE patients, there was lower overall functional integrity of the DMN as well as an increase in posterior hub connections with other modules. Anatomical between-module connectivity was globally decreased. Higher DMN disintegration (DD) coincided with higher anatomical between-module connectivity, whereas both were associated with increased seizure frequency. DD related to seizure frequency through mediating effects of anatomical connectivity, but seizure frequency also correlated with anatomical connectivity through DD, indicating a complex interaction between multimodal networks and symptoms. We provide evidence for dissociated anatomical and functional hub connectivity in TLE. Moreover, shifts in functional hub connections from within to outside the DMN, an overall loss of integrative anatomical communication, and the interaction between the two increase seizure frequency.

  14. Dissociable roles of glucocorticoid and noradrenergic activation on social discounting.

    Science.gov (United States)

    Margittai, Zsofia; van Wingerden, Marijn; Schnitzler, Alfons; Joëls, Marian; Kalenscher, Tobias

    2018-04-01

    People often exhibit prosocial tendencies towards close kin and friends, but generosity decreases as a function of increasing social distance between donor and recipient, a phenomenon called social discounting. Evidence suggests that acute stress affects prosocial behaviour in general and social discounting in particular. We tested the causal role of the important stress neuromodulators cortisol (CORT) and noradrenaline (NA) in this effect by considering two competing hypotheses. On the one hand, it is possible that CORT and NA act in concert to increase generosity towards socially close others by reducing the aversiveness of the cost component in costly altruism and enhancing the emotional salience of vicarious reward. Alternatively, it is equally plausible that CORT and NA exert dissociable, opposing effects on prosocial behaviour based on prior findings implicating CORT in social affiliation, and NA in aggressive and antagonistic tendencies. We pharmacologically manipulated CORT and NA levels in a sample of men (N = 150) and found that isolated hydrocortisone administration promoted prosocial tendencies towards close others, reflected in an altered social discount function, but this effect was offset by concurrent noradrenergic activation brought about by simultaneous yohimbine administration. These results provide inceptive evidence for causal, opposing roles of these two important stress neuromodulators on prosocial behaviour, and give rise to the possibility that, depending on the neuroendocrine response profile, stress neuromodulator action can foster both tend-and-befriend and fight-or-flight tendencies at the same time. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Multiple-photon excitation and dissociation of polyatomic molecules

    International Nuclear Information System (INIS)

    Cantrell, C.D.

    1986-01-01

    This book is Volume 35 in Springer's Topics in Current Physics series designed to provide the interested reader perspective on a rapidly developing research field by gathering together review articles by major players. The editor has accurately highlighted the major results of the multiple-photon excitation (MPE) shock wave of research activity that propagated through the gas-phase chemical physics community during the 1970's. Throughout this period three questions intrigued the photochemists: (1) how is it possible that virtually any polyatomic molecule can efficiently absorb scores of infrared photons from a pulsed CO 2 TEA laser to achieve bond fission? (2) can insight into the dissociation dynamic be gained from this process, and in particular can bonds be made to break selectively? (3) could MPE be used to separate heavy isotopes? The answers to the first two questions are thoroughly examined and answered in the excellent review by Y.T. Lee et al., which itself is worth the price of the book. The question of isotope separation is discussed in two articles, one by Ambartzumian and the other by Cantrell. However, the recent glut of cheap uranium on world energy markets and the decision of DOE to develop atomic multiphoton ionization as the process of choice have resulted in a rapid deflation of interest in MPE separation schemes

  16. Lateral–Medial Dissociation in Orbitofrontal Cortex–Hypothalamus Connectivity

    Science.gov (United States)

    Hirose, Satoshi; Osada, Takahiro; Ogawa, Akitoshi; Tanaka, Masaki; Wada, Hiroyuki; Yoshizawa, Yasunori; Imai, Yoshio; Machida, Toru; Akahane, Masaaki; Shirouzu, Ichiro; Konishi, Seiki

    2016-01-01

    The orbitofrontal cortex (OFC) is involved in cognitive functions, and is also closely related to autonomic functions. The OFC is densely connected with the hypothalamus, a heterogeneous structure controlling autonomic functions that can be divided into two major parts: the lateral and the medial. Resting-state functional connectivity has allowed us to parcellate the cerebral cortex into putative functional areas based on the changes in the spatial pattern of connectivity in the cerebral cortex when a seed point is moved from one voxel to another. In the present high spatial-resolution fMRI study, we investigate the connectivity-based organization of the OFC with reference to the hypothalamus. The OFC was parcellated using resting-state functional connectivity in an individual subject approach, and then the functional connectivity was examined between the parcellated areas in the OFC and the lateral/medial hypothalamus. We found a functional double dissociation in the OFC: the lateral OFC (the lateral orbital gyrus) was more likely connected with the lateral hypothalamus, whereas the medial OFC (the medial orbital and rectal gyri) was more likely connected with the medial hypothalamus. These results demonstrate the fundamental heterogeneity of the OFC, and suggest a potential neural basis of the OFC–hypothalamic functional interaction. PMID:27303281

  17. Dissociable spatial and temporal effects of inhibition of return.

    Directory of Open Access Journals (Sweden)

    Zhiguo Wang

    Full Text Available Inhibition of return (IOR refers to the relative suppression of processing at locations that have recently been attended. It is frequently explored using a spatial cueing paradigm and is characterized by slower responses to cued than to uncued locations. The current study investigates the impact of IOR on overt visual orienting involving saccadic eye movements. Using a spatial cueing paradigm, our experiments have demonstrated that at a cue-target onset asynchrony (CTOA of 400 ms saccades to the vicinity of cued locations are not only delayed (temporal cost but also biased away (spatial effect. Both of these effects are basically no longer present at a CTOA of 1200 ms. At a shorter 200 ms CTOA, the spatial effect becomes stronger while the temporal cost is replaced by a temporal benefit. These findings suggest that IOR has a spatial effect that is dissociable from its temporal effect. Simulations using a neural field model of the superior colliculus (SC revealed that a theory relying on short-term depression (STD of the input pathway can explain most, but not all, temporal and spatial effects of IOR.

  18. Electromagnetic Dissociation of Target Nuclei by $^{208}$Pb Projectiles

    CERN Multimedia

    Petridis, A; Wohn, F K

    2002-01-01

    % NA53 \\\\ \\\\ The purpose of this experiment is to study the process of electromagnetic dissociation (ED) that occurs at impact parameters large enough so that there is no nuclear interaction. In these cases strong electromagnetic fields are produced for a short time at the nucleus. For large charges and ultrarelativistic energies, the intense electromagnetic pulse produces cross-sections much larger than the total hadronic cross-section. These effects place significant constraints on the storage times of the heavy ion beams planned for RHIC and LHC.\\\\ \\\\In this experiment we measure the cross-sections for the one- and two-neutron removal processes resulting from the interaction of 160 and 40~GeV/nucleon Pb beams on Au and Co targets. Thin Au targets were bombarded in the beam line of the NA50 experiment. Gamma rays from the residual nuclides produced in the bombardment were measured to determine the saturation activities of $^{196}$Au and $^{195}$Au resulting from ED of the Au target. This along with cross-se...

  19. Alters in dissociative identity disorder. Metaphors or genuine entities?

    Science.gov (United States)

    Merckelbach, Harald; Devilly, Grant J; Rassin, Eric

    2002-05-01

    How should the different identities (i.e., alters) that are thought to be typical for dissociative identity disorder (DID) be interpreted? Are they just metaphors for different emotional states or are they truly autonomous entities that are capable of willful action? This issue is important because it has implications for the way in which courts may handle cases that involve DID patients. Referring to studies demonstrating that alters of DID patients differ in their memory performance or physiological profile, some authors have concluded that alters are more than just metaphors. We argue that such line of reasoning is highly problematic. There is little consensus among authors about the degree to which various types of memory information (implicit, explicit, procedural) may leak from one to the other alter. Without such theoretical accord, any given outcome of memory studies on DID may be taken as support for the assumption that alters are in some sense "real." As physiological studies on alter activity often lack proper control conditions, most of them are inconclusive as to the status of alters. To date, neither memory studies nor psychobiological studies have delivered compelling evidence that alters of DID patients exist in a factual sense. As a matter of fact, results of these studies are open to multiple interpretations and in no way refute an interpretation of alters in terms of metaphors for different emotional states.

  20. 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)