Particles and fields in fluid turbulence

The understanding of fluid turbulence has considerably progressed in recent years. The application of the methods of statistical mechanics to the description of the motion of fluid particles, i.e. to the Lagrangian dynamics, has led to a new quantitative theory of intermittency in turbulent transport. The first analytical description of anomalous scaling laws in turbulence has been obtained. The underlying physical mechanism reveals the role of statistical integrals of motion in non-equilibrium systems. For turbulent transport, the statistical conservation laws are hidden in the evolution of groups of fluid particles and arise from the competition between the expansion of a group and the change of its geometry. By breaking the scale-invariance symmetry, the statistically conserved quantities lead to the observed anomalous scaling of transported fields. Lagrangian methods also shed new light on some practical issues, such as mixing and turbulent magnetic dynamo.Comment: 165 pages, review article for Rev. Mod. Phy

Recommandations for a Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS)

Background: Cognitive impairment in MS impacts negatively on many patients at all disease stages and in all subtypes. Full clinical cognitive assessment is expensive, requiring expert staff and special equipment. Test versions and normative data are not available for all languages and cultures. Objective: To recommend a brief cognitive assessment for multiple sclerosis (MS) that is optimized for small centers, with one or few staff members, who may not have neuropsychological training and constructed to maximize international use. Methods: An expert committee of twelve members representing the main cultural groups that have so far contributed considerable data about MS cognitive dysfunction was convened. Following exhaustive literature review, peer-reviewed articles were selected to cover a broad spectrum of cultures and scales that targeted cognitive domains vulnerable to MS. Each was rated by two committee members and candidates scales were rated on psychometric qualities (reliability, validity, and sensitivity), international application, ease of administration, feasibility in the specified context, and acceptability to patients. Results: The committee recommended the Symbol Digit Modalities Test, if only 5 minutes was available, with the addition of the California Verbal Learning Test – Second Edition and the Brief Visuospatial Memory Test – Revised learning trials if a further 10 minutes could be allocated for testing. Conclusions: A brief cognitive assessment for MS has been recommended. A validation protocol has been prepared for language groups and validation studies have commenced

"The Impact of PTSD on Veterans' Family Relationships: An Interpretative Phenomenological Inquiry,"

Background: Although there is a significant amount of literature on veterans with PTSD, there is a limited amount of literature on the impact of PTSD on veterans' family relationships and in turn, how these relationships impact healing from trauma. There is evidence that supportive families and friends are immensely helpful to those recovering from PTSD, but how do the symptoms of PTSD impact family relationships and in turn, impact healing from trauma? Objectives: This paper examines the impact of PTSD on veterans' family relationships and the impact of these relationships on healing from trauma. Design: This is a secondary analysis of a currently unpublished study on contemporary peacekeepers healing from trauma. An interpretative phenomenological approach was used as the methodological framework for the study. Settings: Peacekeepers were recruited from Ontario, although they originated from all over Canada and had experienced active service in many different international locations. Participants: Ten contemporary peacekeepers aged 37-46 who had been deployed to Somalia, Rwanda or the former Yugoslavia were interviewed. The peacekeepers had a variety of ranks, specializations, experience, and service records. Each peacekeeper had been receiving treatment for PTSD for at least 2 years. Methods: Data analysis followed the phenomenological method which seeks to uncover the meanings of phenomena experienced by individuals through the analysis of their descriptions. As the themes evolved for the secondary analysis, the primary researcher returned to the transcripts several times for verification of meaning and to find exemplary quotes. Results: Two major themes emerged on the impact of PTSD on veterans' family relationships and how these relationships impact healing from trauma: emotional numbing and anger negatively impacts familial relationships; and emotional withdrawal from family support creates a struggle with healing from trauma. Conclusion: The impact of PTSD on veterans' family relationships, in particular the symptoms of emotional numbing and anger should be heeded. It is recommended that treatment for PTSD include support of the family and interpersonal skills training for military personnel suffering while healing from trauma. Future studies are needed to further explore the impact of PTSD on veterans' family relationships in order to provide the best treatment approaches.This study was funded by an internal grant from the Social Science and Humanities Research Council (SSHRC), University of Western Ontario