255 research outputs found
An optical study of interdiffusion in ZnSe/ZnCdSe
Copyright 1996 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. This article appeared in Applied Physics Letters 69, 1579 (1996) and may be found at
ICD-11 Posttraumatic Stress Disorder and Complex Posttraumatic Stress Disorder in the United States: A Population-Based Study
The primary aim of this study was to provide an assessment of the current prevalence rates of International Classification of Diseases (11th rev.) posttraumatic stress disorder (PTSD) and complex PTSD (CPTSD) among the adult population of the United States and to identify characteristics and correlates associated with each disorder. A total of 7.2% of the sample met criteria for either PTSD or CPTSD, and the prevalence rates were 3.4% for PTSD and 3.8% for CPTSD. Women were more likely than men to meet criteria for both PTSD and CPTSD. Cumulative adulthood trauma was associated with both PTSD and CPTSD; however, cumulative childhood trauma was more strongly associated with CPTSD than PTSD. Among traumatic stressors occurring in childhood, sexual and physical abuse by caregivers were identified as events associated with risk for CPTSD, whereas sexual assault by noncaregivers and abduction were risk factors for PTSD. Adverse childhood events were associated with both PTSD and CPTSD, and equally so. Individuals with CPTSD reported substantially higher psychiatric burden and lower levels of psychological well-being compared to those with PTSD and those with neither diagnosis
Imprinting the memory into paste and its visualization as crack patterns in drying process
In the drying process of paste, we can imprint into the paste the order how
it should be broken in the future. That is, if we vibrate the paste before it
is dried, it remembers the direction of the initial external vibration, and the
morphology of resultant crack patterns is determined solely by the memory of
the direction. The morphological phase diagram of crack patterns and the
rheological measurement of the paste show that this memory effect is induced by
the plasticity of paste.Comment: 4 pages, 3 figures, submitted to JPS
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Excess entropy scaling for soft particle glasses
The transport properties of soft particle glasses, such as dynamic viscosity, normal stress coefficients, and shear-induced diffusivity of its
particles, are determined by the microstructure of the suspension under flow. A thermodynamic measure of the microstructure is the excess
entropy, which we show here accurately correlates the transport properties of soft particle glasses onto master curves across a wide range of
volume fractions, suspending fluid viscosities, particle moduli, and shear rates. The excess entropy for soft particle glasses is approximated
with the two-body excess entropy computed from the pair distribution function extracted from dynamic simulations. The shear viscosity and
normal stress functions diverge and the diffusivity vanishes at a critical excess entropy, corresponding to the yield stress of the suspension.
An effective temperature is computed and is found to vary linearly with the shear stress and the elastic energy of the sheared soft particle
glass. From this, an equation of state is derived relating the excess entropy to the shear stress. Consequently, three of the four transport
properties are determined from the measurement of just one. Finally, a single master curve of particle diffusivity versus excess entropy is
presented that unifies observations for both equilibrium and nonequilibrium suspensions.F.K. and R.T.B. gratefully acknowledge partial financial
support from the National Science Foundation (NSF) (MRSEC
under Award No. DMR-1720595)Center for Dynamics and Control of Material
Evidence of distinct profiles of Posttraumatic Stress Disorder (PTSD) and Complex Posttraumatic Stress Disorder (CPTSD) based on the new ICD-11 Trauma Questionnaire (ICD-TQ)
BACKGROUND: The WHO International Classification of Diseases, 11th version (ICD-11), has proposed two related diagnoses following exposure to traumatic events; Posttraumatic Stress Disorder (PTSD) and Complex PTSD (CPTSD). We set out to explore whether the newly developed ICD-11 Trauma Questionnaire (ICD-TQ) can distinguish between classes of individuals according to the PTSD and CPTSD symptom profiles as per ICD-11 proposals based on latent class analysis. We also hypothesized that the CPTSD class would report more frequent and a greater number of different types of childhood trauma as well as higher levels of functional impairment. Methods Participants in this study were a sample of individuals who were referred for psychological therapy to a National Health Service (NHS) trauma centre in Scotland (N=193). Participants completed the ICD-TQ as well as measures of life events and functioning. RESULTS: Overall, results indicate that using the newly developed ICD-TQ, two subgroups of treatment-seeking individuals could be empirically distinguished based on different patterns of symptom endorsement; a small group high in PTSD symptoms only and a larger group high in CPTSD symptoms. In addition, CPTSD was more strongly associated with more frequent and a greater accumulation of different types of childhood traumatic experiences and poorer functional impairment. LIMITATIONS: Sample predominantly consisted of people who had experienced childhood psychological trauma or been multiply traumatised in childhood and adulthood. CONCLUSIONS: CPTSD is highly prevalent in treatment seeking populations who have been multiply traumatised in childhood and adulthood and appropriate interventions should now be developed to aid recovery from this debilitating condition
An elasto-visco-plastic model for immortal foams or emulsions
A variety of complex fluids consist in soft, round objects (foams, emulsions,
assemblies of copolymer micelles or of multilamellar vesicles -- also known as
onions). Their dense packing induces a slight deviation from their prefered
circular or spherical shape. As a frustrated assembly of interacting bodies,
such a material evolves from one conformation to another through a succession
of discrete, topological events driven by finite external forces. As a result,
the material exhibits a finite yield threshold. The individual objects usually
evolve spontaneously (colloidal diffusion, object coalescence, molecular
diffusion), and the material properties under low or vanishing stress may alter
with time, a phenomenon known as aging. We neglect such effects to address the
simpler behaviour of (uncommon) immortal fluids: we construct a minimal, fully
tensorial, rheological model, equivalent to the (scalar) Bingham model.
Importantly, the model consistently describes the ability of such soft
materials to deform substantially in the elastic regime (be it compressible or
not) before they undergo (incompressible) plastic creep -- or viscous flow
under even higher stresses.Comment: 69 pages, 29 figure
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Transient dynamics of soft particle glasses in startup shear flow. Part I: Microstructure and time scales
The rheology and microstructure of soft particle glasses during startup flow are studied using three-dimensional particle dynamics sim-
ulations at different particle volume fractions and shear rates. The behavior of transient stress depends on the applied shear rate. At
high shear rates, soft particle glasses exhibit a static yield stress signaled by a stress overshoot followed by a relaxation to a steady-
state value. The buildup of the stress is driven by an interplay between structural anisotropy due to an accumulation of particles along
the compression axis and a depletion along the extension axis and a compression of particles that are soft and deformable. At low
shear rates, the stress increase is monotonic and without any stress overshoot. The time scale at which structural anisotropy and the
stress are maximum is correlated to the nonaffine dynamics of SPGs through the persistence time of shear-induced particle collisions
and to the residence time of particles inside their transient cages. The static yield strain γp and the reduced static yield stress σp/σy,
where σy is the dynamic yield stress deduced from steady flow measurements, follow universal behaviors when correlated with the
dimensional shear rate ηs
γ_/G
0
, with ηs being the suspending fluid viscosity and G0 the storage modulus, which expresses the competition
between elastic restoring forces and viscous dissipation. Dense suspensions of thermosensitive core–shell colloids, star-like micelles, and
poly(ethylene oxide)-protected silica particles follow the same universal curves, suggesting the generality of our results.F.K. and R.T.B. gratefully acknowledge financial support
from the National Science Foundation (MRSEC under Award
No. DMR-1720595). B.F.D.D. and M.C. acknowledge
financial support from the Innovative Training Network
Dodynet (European Program H2020-MSCA-ITN-2017;
Grant Agreement No. 765811).Center for Dynamics and Control of Material
Trauma-focused treatment outcome for complex PTSD patients: results of an intensive treatment programme
Objective
The objective of the current study is to determine whether individuals classified as having CPTSD can benefit from an intensive trauma-focused treatment, resulting in decreased PTSD and CPTSD symptoms, and loss of diagnoses.
Method
Patients diagnosed with PTSD (N = 308) took part in an intensive 8-day treatment programme combining prolonged exposure, EMDR therapy, psycho-education, and physical activity. The treatment was not phase-based in that it did not contain a stabilization phase or skill training prior to therapy. CPTSD diagnosis was assessed by means of the International Trauma Questionnaire (ITQ) and PTSD diagnosis was assessed with both the ITQ and CAPS-5. Treatment response was measured with the CAPS-5, PCL-5, and ITQ.
Results
Symptoms of both PTSD and CPTSD significantly decreased from pre- to post-treatment resulting in a significant loss of CAPS-5 based PTSD (74.0%) and ITQ-based PTSD and CPTSD diagnoses (85.0% and 87.7%, respectively). No adverse events occurred in terms of suicides, suicide attempts, or hospital admissions.
Conclusions
The results are supportive of the notion that the majority of patients classified as having CPTSD strongly benefit from an intensive trauma-focused treatment for their PTSD
Alternative models of disorders of traumatic stress based on the new ICD-11 proposals
Objective Although there is emerging evidence for the factorial validity of the distinction between Posttraumatic Stress Disorder (PTSD) and Complex PTSD (CPTSD) proposed in ICD-11, such evidence has been predominantly based on using selected items from individual scales that describe these factors. We have attempted to address this gap in the literature by testing a range of alternative models of disorders of traumatic stress using a broader range of symptoms and standardised measures. Method Participants in this cross-sectional study were a sample of individuals who were referred for psychological therapy to a National Health Service (NHS) trauma centre in Scotland (N=195). Participants were recruited over a period of 18 months and completed measures of stressful life events, DSM-5 PTSD, emotion dysregulation, self–esteem, and interpersonal difficulties. Results Overall, results indicate that a structural model incorporating six first-order factors (re-experiencing, avoidance of traumatic reminders, sense of threat, affective dysregulation, negative self-concept, and disturbances in relationships) and two second order factors (PTSD and Disturbances in Self-Organization [DSO]) was the best fitting. The model presented with good concurrent validity. Childhood trauma was found to be more strongly associated with DSO than PTSD. Conclusions Our results are in support of the ICD-11 proposals for PTSD and CPTSD
The International Trauma Questionnaire: development of a self-report measure of ICD-11 PTSD and complex PTSD
Objective: The purpose of this study was to finalize the development of the International Trauma Questionnaire (ITQ); a self-report diagnostic measure of Posttraumatic Stress Disorder (PTSD) and Complex PTSD (CPTSD), as defined in the 11th version of the International Classification of Diseases (ICD-11).Method: The optimal symptom indicators of PTSD and CPTSD were identified by applying item response theory (IRT) analysis to data from a trauma-exposed community sample (n =1051) and a trauma-exposed clinical sample (n = 247) from the United Kingdom. The validity of the optimized 12-item ITQ was assessed with confirmatory factor analyses. Diagnostic rates were estimated and compared to previous validation studies.Results: The latent structure of the 12-item, optimized ITQ was consistent with prior findings, and diagnostic rates of PTSD and CPTSD were in line with previous estimates.Conclusion: The ITQ is a brief, simply-worded measure of the core features of PTSD and CPTSD. It is consistent with the organizing principles of the ICD-11 to maximize clinical utility and international applicability through a focus on a limited but central set of symptoms. The measure is freely available and can be found in the body of this paper
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