Multiple passages of light through an absorption inhomogeneity in optical imaging of turbid media

The multiple passages of light through an absorption inhomogeneity of finite size deep within a turbid medium is analyzed for optical imaging using the ``self-energy'' diagram. The nonlinear correction becomes more important for an inhomogeneity of a larger size and with greater contrast in absorption with respect to the host background. The nonlinear correction factor agrees well with that from Monte Carlo simulations for CW light. The correction is about $50$ in near infrared for an absorption inhomogeneity with the typical optical properties found in tissues and of size of five times the transport mean free path.Comment: 3 figure

Functional somatic disorders: discussion paper for a new common classification for research and clinical use

Background Functional somatic symptoms and disorders are common and complex phenomena involving both bodily and brain processes. They pose major challenges across medical specialties. These disorders are common and have significant impacts on patients’ quality of life and healthcare costs. Main body We outline five problems pointing to the need for a new classification: (1) developments in understanding aetiological mechanisms; (2) the current division of disorders according to the treating specialist; (3) failure of current classifications to cover the variety of disorders and their severity (for example, patients with symptoms from multiple organs systems); (4) the need to find acceptable categories and labels for patients that promote therapeutic partnership; and (5) the need to develop clinical services and research for people with severe disorders. We propose ‘functional somatic disorders’ (FSD) as an umbrella term for various conditions characterised by persistent and troublesome physical symptoms. FSDs are diagnosed clinically, on the basis of characteristic symptom patterns. As with all diagnoses, a diagnosis of FSD should be made after considering other possible somatic and mental differential diagnoses. We propose that FSD should occupy a neutral space within disease classifications, favouring neither somatic disease aetiology, nor mental disorder. FSD should be subclassified as (a) multisystem, (b) single system, or (c) single symptom. While additional specifiers may be added to take account of psychological features or co-occurring diseases, neither of these is sufficient or necessary to make the diagnosis. We recommend that FSD criteria are written so as to harmonise with existing syndrome diagnoses. Where currently defined syndromes fall within the FSD spectrum – and also within organ system-specific chapters of a classification – they should be afforded dual parentage (for example, irritable bowel syndrome can belong to both gastrointestinal disorders and FSD). Conclusion We propose a new classification, ‘functional somatic disorder’, which is neither purely somatic nor purely mental, but occupies a neutral space between these two historical poles. This classification reflects both emerging aetiological evidence of the complex interactions between brain and body and the need to resolve the historical split between somatic and mental disorders

Rethinking psychopharmacotherapy: The role of treatment context and brain plasticity in antidepressant and antipsychotic interventions

AbstractEmerging evidence indicates that treatment context profoundly affects psychopharmacological interventions. We review the evidence for the interaction between drug application and the context in which the drug is given both in human and animal research. We found evidence for this interaction in the placebo response in clinical trials, in our evolving knowledge of pharmacological and environmental effects on neural plasticity, and in animal studies analyzing environmental influences on psychotropic drug effects. Experimental placebo research has revealed neurobiological trajectories of mechanisms such as patients’ treatment expectations and prior treatment experiences. Animal research confirmed that “enriched environments” support positive drug effects, while unfavorable environments (low sensory stimulation, low rates of social contacts) can even reverse the intended treatment outcome. Finally we provide recommendations for context conditions under which psychotropic drugs should be applied. Drug action should be steered by positive expectations, physical activity, and helpful social and physical environmental stimulation. Future drug trials should focus on fully controlling and optimizing such drug×environment interactions to improve trial sensitivity and treatment outcome

DNA unzipped under a constant force exhibits multiple metastable intermediates

Single molecule studies, at constant force, of the separation of double-stranded DNA into two separated single strands may provide information relevant to the dynamics of DNA replication. At constant applied force, theory predicts that the unzipped length as a function of time is characterized by jumps during which the strands separate rapidly, followed by long pauses where the number of separated base pairs remains constant. Here, we report previously uncharacterized observations of this striking behavior carried out on a number of identical single molecules simultaneously. When several single lphage molecules are subject to the same applied force, the pause positions are reproducible in each. This reproducibility shows that the positions and durations of the pauses in unzipping provide a sequence-dependent molecular fingerprint. For small forces, the DNA remains in a partially unzipped state for at least several hours. For larger forces, the separation is still characterized by jumps and pauses, but the double-stranded DNA will completely unzip in less than 30 min

Clinical Psychology and the COVID-19 Pandemic: A Mixed Methods Survey Among Members of the European Association of Clinical Psychology and Psychological Treatment (EACLIPT)

Background: The COVID-19 pandemic has affected people globally both physically and psychologically. The increased demands for mental health interventions provided by clinical psychologists, psychotherapists and mental health care professionals, as well as the rapid change in work setting (e.g., from face-to-face to video therapy) has proven challenging. The current study investigates European clinical psychologists and psychotherapists' views on the changes and impact on mental health care that occurred due to the COVID-19 pandemic. It further aims to explore individual and organizational processes that assist clinical psychologists' and psychotherapists' in their new working conditions, and understand their needs and priorities. Method: Members of the European Association of Clinical Psychology and Psychological Treatment (EACLIPT) were invited (N = 698) to participate in a survey with closed and open questions covering their experiences during the first wave of the pandemic from June to September 2020. Participants (n = 92) from 19 European countries, mostly employed in universities or hospitals, completed the online survey. Results: Results of qualitative and quantitative analyses showed that clinical psychologists and psychotherapists throughout the first wave of the COVID-19 pandemic managed to continue to provide treatments for patients who were experiencing emotional distress. The challenges (e.g., maintaining a working relationship through video treatment) and opportunities (e.g., more flexibleflexibleflexibleworking hours) of working through this time were identified. Conclusions: Recommendations for mental health policies and professional organizations are identified, such as clear guidelines regarding data security and workshops on conducting video therapy

Theory of biopolymer stretching at high forces

We provide a unified theory for the high force elasticity of biopolymers solely in terms of the persistence length, $\xi_p$, and the monomer spacing, $a$. When the force f>\fh \sim k_BT\xi_p/a^2 the biopolymers behave as Freely Jointed Chains (FJCs) while in the range \fl \sim k_BT/\xi_p < f < \fh the Worm-like Chain (WLC) is a better model. We show that $\xi_p$ can be estimated from the force extension curve (FEC) at the extension $x\approx 1/2$ (normalized by the contour length of the biopolymer). After validating the theory using simulations, we provide a quantitative analysis of the FECs for a diverse set of biopolymers (dsDNA, ssRNA, ssDNA, polysaccharides, and unstructured PEVK domain of titin) for $x \ge 1/2$. The success of a specific polymer model (FJC or WLC) to describe the FEC of a given biopolymer is naturally explained by the theory. Only by probing the response of biopolymers over a wide range of forces can the $f$-dependent elasticity be fully described.Comment: 20 pages, 4 figure

Cognitive-behaviour therapy for patients with Abridged Somatization Disorder (SSI 4,6) in primary care: a randomized, controlled study

Abstract Background Somatoform disorders are characterized by the presence of multiple somatic symptoms without an organic cause that completely explains their symptoms. These patients generate a high cost in health services. We aim to evaluate the effectiveness and feasibility of a cognitive-behaviour therapy (CBT) programme, administered in group and individual formats in primary care for patients who are diagnosed with abridged somatization disorder. Method/design Design: Multicentre, randomized, controlled trial involving 3 groups, one of which is the control group consisting of standardized recommended treatment for somatization disorder in primary care (Smith's norms) and the 2 others, the intervention groups, consisting of cognitive-behavioural therapy (10 sessions) administered in individual format (intervention group 1) or in group format (intervention group 2). Setting: 29 primary care health centres in the province of Zaragoza and 3 primary care health centres in the province of Mallorca, Spain. Sample: N = 204 patients, (68 in each of the three groups), aged 18–65 years, able to understand and read Spanish, who fulfil Escobar's criteria of Abridgged Somatization Disorder (SSI 4,6), stable with pharmacotherapy over the previous month, and who will remain stable for the next 3 months in the doctor's opinion, having signed informed consent. Intervention: Control group: Standardized recommended treatment for somatization disorder in primary care (Smith's norms). Intervention group: 10 weekly sessions of CBT, following a protocol designed by Prof. Escobar's group at UMDNJ, USA. There are 2 different treatment conditions: individual and group format. Measurements: Survey on the use of health services, number and severity of somatic symptoms, anxiety, depression, quality of life and clinical global impression. The interviewers will not know which group the patient belongs to (blind). The assessments will be carried out at baseline, post-treatment, 6 months and 12 post-treatment. Main variables: Utilization of health services, number and severity of somatic symptoms. Analysis: The analysis will be per intent to treat. We will use the general linear models of the SPSS v.15 statistical package, to analyse the effect of treatment on the result variable (utilization of health services, number and severity of somatic symptoms). Discussion It is necessary to develop more effective psychological treatments for somatoform disorders. This randomised clinical trial will determine whether cognitive behaviour therapy, both in group or in individual format, is effective for the treatment of these patients. Trial registration Current controlled trials ISRCTN69944771</p