Regge Calculus as a Fourth Order Method in Numerical Relativity

The convergence properties of numerical Regge calculus as an approximation to continuum vacuum General Relativity is studied, both analytically and numerically. The Regge equations are evaluated on continuum spacetimes by assigning squared geodesic distances in the continuum manifold to the squared edge lengths in the simplicial manifold. It is found analytically that, individually, the Regge equations converge to zero as the second power of the lattice spacing, but that an average over local Regge equations converges to zero as (at the very least) the third power of the lattice spacing. Numerical studies using analytic solutions to the Einstein equations show that these averages actually converge to zero as the fourth power of the lattice spacing.Comment: 14 pages, LaTeX, 8 figures mailed in separate file or email author directl

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 ICD-11 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 where the prevalence rate for PTSD was 3.4% and for CPTSD was 3.8%. Females were more likely than males to meet criteria for both PTSD and CPTSD. Cumulative adulthood trauma was associated with 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 while sexual assault (by non-caregiver) and abduction were risk factors for PTSD. Adverse childhood events (ACEs) were associated with both PTSD and CPTSD and equally so. Those with CPTSD reported substantially higher psychiatric burden and lower psychological well-being compared to those with PTSD, and with neither diagnosis

The role of negative cognitions, emotion regulation strategies, and attachment style in complex post-traumatic stress disorder: Implications for new and existing therapies

Objective We set out to investigate the association between negative trauma-related cognitions, emotional regulation strategies, and attachment style and Complex Posttraumatic Stress Disorder (CPTSD). As the evidence regarding the treatment of CPTSD is emerging, investigating psychological factors that are associated with CPTSD can inform the adaptation or the development of effective interventions for CPTSD. Method A cross sectional design was employed. Measures of CPTSD, negative trauma-related cognitions, emotion regulation strategies, and attachment style were completed by a British clinical sample of trauma-exposed patients (N = 171). Logistic regression analysis was used to assess the predictive utility of these psychological factors on diagnosis of CPTSD as compared to PTSD. Results It was found that the most important factor in the diagnosis of CPTSD was negative trauma-related cognitions about the self, followed by attachment anxiety, and expressive suppression. Conclusions Targeting negative thoughts and attachment representations while promoting skills acquisition in emotional regulation hold promise in the treatment of CPTSD. Further research is required on the development of appropriate models to treat CPTSD that tackle skills deficit in these areas

Evidence for the coherence and integrity of the complex PTSD (CPTSD) diagnosis: response to Achterhof et al., (2019) and Ford (2020)

This letter to the editor responds to a recent EJPT editorial and following commentary which express concerns about the validity of the ICD-11 complex PTSD (CPTSD) diagnosis. Achterhof and colleagues caution that latent profile analyses and latent class analyses, which have been frequently used to demonstrate the discriminative validity of the ICD-11 PTSD and CPTSD constructs, have limitations and cannot be relied on to definitively determine the validity of the diagnosis. Ford takes a broader perspective and introduces the concept of ‘cPTSD’ which describes a wide ranging set of symptoms identified from studies related to DSM-IV, DSM-V and ICD-11 and proposes that the validity of the ICD-11 CPTSD is in question as it does not address the multiple symptoms identified from previous trauma-related disorders. We argue that ICD-11 CPTSD is a theory-driven, empirically supported construct that has internal consistency and conceptual coherence and that it need not explain nor resolve the inconsistencies of past formulations to demonstrate its validity. We do agree with Ford and with Achterhof and colleagues that no one single statistical process can definitively answer the question of whether CPTSD is a valid construct. We reference several studies utilizing many different statistical approaches implemented across several countries, the overwhelming majority of which have supported the validity of ICD-11 as a unique construct. We conclude with our own cautions about ICD-11 CPTSD research to date and identify important next steps

Validation of the International Trauma Interview (ITI) for the Clinical Assessment of ICD-11 Posttraumatic Stress Disorder (PTSD) and Complex PTSD (CPTSD) in a Lithuanian Sample

Background: The 11th revision of the International Classification of Diseases (ICD-11) includes a new diagnosis of complex posttraumatic stress disorder (CPTSD). The International Trauma Interview (ITI) is a novel clinician-administered diagnostic interview for the assessment of ICD-11 PTSD and CPTSD. Objective: The aim of this study was to evaluate the psychometric properties of the ITI in a Lithuanian sample in relation to interrater agreement, latent structure, internal reliability, as well as convergent and discriminant validity. Method: In total, 103 adults with a history of various traumatic experiences participated in the study. The sample was predominantly female (83.5%), with a mean age of 32.64 years (SD = 9.36). For the assessment of ICD-11 PTSD and CPTSD, the ITI and the self-report International Trauma Questionnaire (ITQ) were used. Mental health indicators, such as depression, anxiety, and dissociation, were measured using self-report questionnaires. The latent structure of the ITI was evaluated using confirmatory factor analysis (CFA). In order to test the convergent and discriminant validity of the ITI we conducted a structural equation model (SEM).Results: Overall, based on the ITI, 18.4% of participants fulfilled diagnostic criteria for PTSD and 21.4% for CPTSD. A second-order two-factor CFA model of the ITI PTSD and disturbances in self-organization (DSO) symptoms demonstrated a good fit. The associations with various mental health indicators supported the convergent and discriminant validity of the ITI. The clinician-administered ITI and self-report ITQ had poor to moderate diagnostic agreement across different symptom clusters. Conclusion: The ITI is a reliable and valid tool for assessing and diagnosing ICD-11 PTSD and CPTSD

Posttraumatic stress disorder (PTSD) and complex PTSD (CPTSD) as per ICD-11 proposals: A population study in Israel

Background: The current study sought to advance the existing literature by providing the first assessment of the factorial and discriminant validity of the ICD-11 proposals for PTSD and CPTSD in a nation-wide level.Methods: A nationally representative sample from Israel (n = 1003) using a disorder-specific measure (ITQ; International Trauma Questionnaire) in order to assess PTSD and Complex PTSD along with the Life Events Checklist and the World Health Organization Well-Being Index.Results: Estimated prevalence rates of PTSD and CPTSD were 9.0% and 2.6% respectively. The structural analyses indicated that PTSD and disturbances in self-organization symptom clusters were multidimensional, but not necessarily hierarchical, in nature and there were distinct classes that were consistent with PTSD and CPTSD. Conclusions: These results partially support the factorial validity and strongly support the discriminant validity of the ICD-11 proposals for PTSD and CPTSD in a nationally representative sample using a disorder-specific measure, findings also supported the international applicability of these diagnoses.Further research is required to determine the prevalence rates of PTSD and CPTSD in national representative samples across different countries and explore the predictive utility of different types of traumatic life events on PTSD and CPTSD

Model validation for a noninvasive arterial stenosis detection problem

Copyright @ 2013 American Institute of Mathematical SciencesA current thrust in medical research is the development of a non-invasive method for detection, localization, and characterization of an arterial stenosis (a blockage or partial blockage in an artery). A method has been proposed to detect shear waves in the chest cavity which have been generated by disturbances in the blood flow resulting from a stenosis. In order to develop this methodology further, we use both one-dimensional pressure and shear wave experimental data from novel acoustic phantoms to validate corresponding viscoelastic mathematical models, which were developed in a concept paper [8] and refined herein. We estimate model parameters which give a good fit (in a sense to be precisely defined) to the experimental data, and use asymptotic error theory to provide confidence intervals for parameter estimates. Finally, since a robust error model is necessary for accurate parameter estimates and confidence analysis, we include a comparison of absolute and relative models for measurement error.The National Institute of Allergy and Infectious Diseases, the Air Force Office of Scientific Research, the Deopartment of Education and the Engineering and Physical Sciences Research Council (EPSRC)

A randomised controlled trial of positive memory training for the treatment of depression within schizophrenia

Abstract Background: Depression is highly prevalent within individuals diagnosed with schizophrenia, and is associated with an increased risk of suicide. There are no current evidence based treatments for low mood within this group. The specific targeting of co-morbid conditions within complex mental health problems lends itself to the development of short-term structured interventions which are relatively easy to disseminate within health services. A brief cognitive intervention based on a competitive memory theory of depression, is being evaluated in terms of its effectiveness in reducing depression within this group. Methods/Design: This is a single blind, intention-to-treat, multi-site, randomized controlled trial comparing Positive Memory Training plus Treatment as Usual with Treatment as Usual alone. Participants will be recruited from two NHS Trusts in Southern England. In order to be eligible, participants must have a DSM-V diagnosis of schizophrenia or schizo-affective disorder and exhibit at least a mild level of depression. Following baseline assessment eligible participants will be randomly allocated to either the Positive Memory Training plus Treatment as Usual group or the Treatment as Usual group. Outcome will be assessed at the end of treatment (3-months) and at 6-month and 9-month post randomization by assessors blind to group allocation. The primary outcome will be levels of depression and secondary outcomes will be severity of psychotic symptoms and cost-effectiveness. Semi-structured interviews will be conducted with all participants who are allocated to the treatment group so as to explore the acceptability of the intervention. Discussion: Cognitive behaviour therapy is recommended for individuals diagnosed with schizophrenia. However, the number of sessions and length of training required to deliver this intervention has caused a limit in availability. The current trial will evaluate a short-term structured protocol which targets a co-morbid condition often considered of primary importance by service users. If successful the intervention will be an important addition to current initiatives aimed at increasing access to psychological therapies for people diagnosed with severe mental health problems. Trial registration: Current Controlled Trials. ISRCTN99485756. Registered 13 March 2014

A longitudinal examination of the relationship between trauma-related cognitive factors and internalising and externalising psychopathology in physically injured children

Cognitive models of posttraumatic stress disorder (PTSD) highlight maladaptive posttrauma appraisals, trauma memory qualities, and coping strategies, such as rumination or thought suppression, as key processes that maintain PTSD symptoms. Anxiety, depression and externalising symptoms can also present in children in the aftermath of trauma, yet there has been little empirical investigation of the potential relevance of posttrauma cognitive processes for such difficulties. Here, we examined whether: a) acute maladaptive cognitive processes (specifically, maladaptive appraisals, memory qualities, and cognitive coping) were associated with symptoms of PTSD, internalising, and externalising at 1-month posttrauma (T1); and b) changes in these cognitive processes predicted symptom change at a follow-up assessment 6 months later (T2). We recruited 132 6–13 year old children and their parents from emergency departments following the child’s experience of an acute trauma. Children self-reported on their maladaptive appraisals, trauma-memory and cognitive coping strategies, along with symptoms of PTSD, anxiety and depression. Parents also rated children’s internalising and externalising symptoms. We found each cognitive process to be robustly associated with PTSD and non-PTSD internalising symptoms at T1, and change in each predicted change in symptoms to T2. Maladaptive appraisals and cognitive coping were unique predictors of children’s posttrauma internalising. Effects were partially retained even controlling for co-occurring PTSD symptoms. There was less evidence that trauma-specific cognitive processes were associated with externalising symptoms. Findings suggest aspects of cognitive models of PTSD are applicable to broader posttrauma psychopathology, and have implications for how we understand and target children’s posttrauma psychological adjustment

The impact of injuries study. Multicentre study assessing physical, psychological, social and occupational functioning post injury - a protocol

Background: Large numbers of people are killed or severely injured following injuries each year and these injuries place a large burden on health care resources. The majority of the severely injured are not fully recovered 12-18 months later. Psychological disorders are common post injury and are associated with poorer functional and occupational outcomes. Much of this evidence comes from countries other than the UK, with differing health care and compensation systems. Early interventions can be effective in treating psychological morbidity, hence the scale and nature of the problem and its impact of functioning in the UK must be known before services can be designed to identify and manage psychological morbidity post injury. Methods/Design : A longitudinal multi-centre study of 680 injured patients admitted to hospital in four areas across the UK: Nottingham, Leicester/Loughborough, Bristol and Surrey. A stratified sample of injuries will ensure a range of common and less common injuries will be included. Participants will complete a baseline questionnaire about their injury and pre-injury quality of life, and follow-up questionnaires 1, 2, 4, and 12 months post injury. Measures will include health and social care utilisation, perceptions of recovery, physical, psychological, social and occupational functioning and health-related quality of life. A nested qualitative study will explore the experiences of a sample of participants, their carers and service providers to inform service design. Discussion: This study will quantify physical, psychological, social and occupational functioning and health and social care utilisation following a range of different types of injury and will assess the impact of psychological disorders on function and health service use. The findings will be used to guide the development of interventions to maximise recovery post injury