222 research outputs found

    Analytical model of brittle destruction based on hypothesis of scale similarity

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    The size distribution of dust particles in nuclear fusion devices is close to the power function. A function of this kind can be the result of brittle destruction. From the similarity assumption it follows that the size distribution obeys the power law with the exponent between -4 and -1. The model of destruction has much in common with the fractal theory. The power exponent can be expressed in terms of the fractal dimension. Reasonable assumptions on the shape of fragments concretize the power exponent, and vice versa possible destruction laws can be inferred on the basis of measured size distributions.Comment: 10 pages, 3 figure

    Effects of precompetition state anxiety interventions on performance time and accuracy among amateur soccer players: Revisiting the matching hypothesis

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    In this study, we tested the matching ypothesis, which contends that administration of a cognitive or somatic anxiety intervention should be matched to a participant's dominant anxiety response. Sixty-one male soccer players (mean age 31.6 years, s=6.3) were assigned to one of four groups based on their responses to the Competitive State Anxiety Inventory-2, which was modified to include a directional scale. Interventions were randomly administered in a counterbalanced order 10 min before each performance trial on a soccer skill test. The dominantly cognitive anxious group (n=17), the dominantly somatic anxious group (n=17), and the non-anxious control intervention group (n=14) completed a baseline performance trial. The second and third trials were completed with random administration of brief cognitive and somatic interventions. The non-anxious control group (n=13) completed three trials with no intervention. A mixed-model, GroupTreatment multivariate analysis of variance indicated significant (P0.05), or performance time or accuracy (P>0.05). The present findings do not provide support for the matching hypothesis for state anxiety intensity and direction, or for performance

    Mindfulness-based interventions for people diagnosed with a current episode of an anxiety or depressive disorder: a meta-analysis of randomised controlled trials

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    Objective Mindfulness-based interventions (MBIs) can reduce risk of depressive relapse for people with a history of recurrent depression who are currently well. However, the cognitive, affective and motivational features of depression and anxiety might render MBIs ineffective for people experiencing current symptoms. This paper presents a meta-analysis of randomised controlled trials (RCTs) of MBIs where participants met diagnostic criteria for a current episode of an anxiety or depressive disorder. Method Post-intervention between-group Hedges g effect sizes were calculated using a random effects model. Moderator analyses of primary diagnosis, intervention type and control condition were conducted and publication bias was assessed. Results Twelve studies met inclusion criteria (n = 578). There were significant post-intervention between-group benefits of MBIs relative to control conditions on primary symptom severity (Hedges g = −0.59, 95% CI = −0.12 to −1.06). Effects were demonstrated for depressive symptom severity (Hedges g = −0.73, 95% CI = −0.09 to −1.36), but not for anxiety symptom severity (Hedges g = −0.55, 95% CI = 0.09 to −1.18), for RCTs with an inactive control (Hedges g = −1.03, 95% CI = −0.40 to −1.66), but not where there was an active control (Hedges g = 0.03, 95% CI = 0.54 to −0.48) and effects were found for MBCT (Hedges g = −0.39, 95% CI = −0.15 to −0.63) but not for MBSR (Hedges g = −0.75, 95% CI = 0.31 to −1.81). Conclusions This is the first meta-analysis of RCTs of MBIs where all studies included only participants who were diagnosed with a current episode of a depressive or anxiety disorder. Effects of MBIs on primary symptom severity were found for people with a current depressive disorder and it is recommended that MBIs might be considered as an intervention for this population

    New Strategies for Combining Mindfulness with Integrative Cognitive Behavioral Therapy for the Treatment of Generalized Anxiety Disorder

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    Generalized anxiety disorder (GAD) severely impacts social functioning, distress levels, and utilization of medical care compared with that of other major psychiatric disorders. Neither pharmacological nor psychotherapy interventions have adequately controlled cardinal symptoms of GAD: pervasive excessive anxiety and uncontrollable worry. Research has established cognitive behavioral therapy (CBT) as the most effective psychotherapy for controlling GAD; however, outcomes remain at only 50% reduction, with high relapse rates. Mindfulness has been integrated with CBT to treat people suffering from numerous psychiatric disorders, with mindfulness based stress reduction (MBSR) being the most researched. Preliminary evidence supports MBSR’s potential for controlling GAD symptoms and key researchers suggest mindfulness practices possess key elements for treating GAD. Classical mindfulness (CM) differs significantly from MBSR and possesses unique potentials for directly targeting process and state GAD symptoms inadequately treated by CBT. This article introduces the theory and practice of CM, its differences from MBSR, and a critical review of MBSR and CBT treatments for GAD. CM strategies designed to complement CBT targeting cardinal GAD symptoms are outlined with a case study illustrating its use

    The working alliance in a randomized controlled trial comparing online with face-to-face cognitive-behavioral therapy for depression

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    Background: Although numerous efficacy studies in recent years have found internet-based interventions for depression to be effective, there has been scant consideration of therapeutic process factors in the online setting. In face-to face therapy, the quality of the working alliance explains variance in treatment outcome. However, little is yet known about the impact of the working alliance in internet-based interventions, particularly as compared with face-to-face therapy. Methods: This study explored the working alliance between client and therapist in the middle and at the end of a cognitive-behavioral intervention for depression. The participants were randomized to an internet-based treatment group (n = 25) or face-to-face group (n = 28). Both groups received the same cognitive behavioral therapy over an 8-week timeframe. Participants completed the Beck Depression Inventory (BDI) post-treatment and the Working Alliance Inventory at mid- and post- treatment. Therapists completed the therapist version of the Working Alliance Inventory at post-treatment. Results: With the exception of therapists' ratings of the tasks subscale, which were significantly higher in the online group, the two groups' ratings of the working alliance did not differ significantly. Further, significant correlations were found between clients' ratings of the working alliance and therapy outcome at post-treatment in the online group and at both mid- and post-treatment in the face-to-face group. Correlation analysis revealed that the working alliance ratings did not significantly predict the BDI residual gain score in either group. Conclusions: Contrary to what might have been expected, the working alliance in the online group was comparable to that in the face-to-face group. However, the results showed no significant relations between the BDI residual gain score and the working alliance ratings in either group

    Anxiety disorders in headache patients in a specialised clinic: prevalence and symptoms in comparison to patients in a general neurological clinic

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    Data from several studies indicate an association of headache with anxiety disorders. In this study, we assessed and differentiated anxiety disorders in 100 headache patients by using the PSWQ (Penn State Worry Questionnaire) screening tool for generalised anxiety disorder (GAD) and the ACQ (Agoraphobic Cognitions Questionnaire) and BSQ (Body Sensation Questionnaire) for panic disorder (PD). Control groups were constructed: (1) on the basis of epidemiological studies on PD and GAD in the general population and (2) by including neurological patients. 37.0% of headache patients had a GAD. 27% of headache patients met the score for PD in the BSQ, 4.0% in the ACQ. Significant results were obtained in comparison to the general population (p < 0.001) and with regard to GAD in comparison with a sample of neurological patients (p < 0.005). The BSQ significantly correlated with the number of medication days (p < 0.005). The results confirm the increased prevalence of GAD in headache patients. PD seems to increase the risk of medication overuse

    Implementation of Internet-based preventive interventions for depression and anxiety: role of support? The design of a randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Internet-based self-help is an effective preventive intervention for highly prevalent disorders, such as depression and anxiety. It is not clear, however, whether it is necessary to offer these interventions with professional support or if they work without any guidance. In case support is necessary, it is not clear which level of support is needed. This study examines whether an internet-based self-help intervention with a coach is more effective than the same intervention without a coach in terms of clinical outcomes, drop-out and economic costs. Moreover, we will investigate which level of support by a coach is more effective compared to other levels of support.</p> <p>Methods</p> <p>In this randomized controlled trial, a total of 500 subjects (18 year and older) from the general population with mild to moderate depression and/or anxiety will be assigned to one of five conditions: (1) web-based problem solving through the internet (self-examination therapy) without a coach; (2) the same as 1, but with the possibility to ask help from a coach on the initiative of the respondent (on demand, by email); (3) the same as 1, but with weekly scheduled contacts initiated by a coach (once per week, by email); (4) weekly scheduled contacts initiated by a coach, but no web-based intervention; (5) information only (through the internet). The interventions will consist of five weekly lessons. Primary outcome measures are symptoms of depression and anxiety. Secondary outcome measures are drop-out from the intervention, quality of life, and economic costs. Other secondary outcome measures that may predict outcome are also studied, e.g. client satisfaction and problem-solving skills. Measures are taken at baseline (pre-test), directly after the intervention (post-test, five weeks after baseline), 3 months later, and 12 months later. Analysis will be conducted on the intention-to-treat sample.</p> <p>Discussion</p> <p>This study aims to provide more insight into the clinical effectiveness, differences in drop-out rate and costs between interventions with and without support, and in particular different levels of support. This is important to know in relation to the dissemination of internet-based self-help interventions.</p> <p>Trial Registration</p> <p>Nederlands Trial Register (NTR): TC1355</p

    Efficacy of a multimodal physiotherapy treatment program for hip osteoarthritis: a randomised placebo-controlled trial protocol

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    <p>Abstract</p> <p>Background</p> <p>Hip osteoarthritis (OA) is a common condition leading to pain, disability and reduced quality of life. There is currently limited evidence to support the use of conservative, non-pharmacological treatments for hip OA. Exercise and manual therapy have both shown promise and are typically used together by physiotherapists to manage painful hip OA. The aim of this randomised controlled trial is to compare the efficacy of a physiotherapy treatment program with placebo treatment in reducing pain and improving physical function.</p> <p>Methods</p> <p>The trial will be conducted at the University of Melbourne Centre for Health, Exercise and Sports Medicine. 128 participants with hip pain greater or equal to 40/100 on visual analogue scale (VAS) and evidence of OA on x-ray will be recruited. Treatment will be provided by eight community physiotherapists in the Melbourne metropolitan region. The active physiotherapy treatment will comprise a semi-structured program of manual therapy and exercise plus education and advice. The placebo treatment will consist of sham ultrasound and the application of non-therapeutic gel. The participants and the study assessor will be blinded to the treatment allocation. Primary outcomes will be pain measured by VAS and physical function recorded on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) immediately after the 12 week intervention. Participants will also be followed up at 36 weeks post baseline.</p> <p>Conclusions</p> <p>The trial design has important strengths of reproducibility and reflecting contemporary physiotherapy practice. The findings from this randomised trial will provide evidence for the efficacy of a physiotherapy program for painful hip OA.</p> <p>Trial Registration</p> <p>Australian New Zealand Clinical Trials Registry reference: ACTRN12610000439044</p

    Group mindfulness based cognitive therapy vs group support for self-injury among young people: Study protocol for a randomised controlled trial

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    Background: Non-suicidal self-injury (NSSI) is a transdiagnostic behaviour that can be difficult to treat; to date no evidence based treatment for NSSI exists. Mindfulness Based Cognitive Therapy (MBCT) specifically targets the mechanisms thought to initiate and maintain NSSI, and thus appears a viable treatment option. The aims of the current study are to test the ability of MBCT to reduce the frequency and medical severity of NSSI, and explore the mechanisms by which MBCT exerts its effect. Methods/Design: We will conduct a parallel group randomised controlled trial of Mindfulness Based Cognitive Therapy (MBCT) versus Supportive Therapy (ST) in young people aged 18-25 years. Computerised block randomisation will be used to allocate participants to groups. All participants will meet the proposed DSM-5 criteria for NSSI (i.e. five episodes in the last twelve months). Participants will be excluded if they: 1) are currently receiving psychological treatment, 2) have attempted suicide in the previous 12 months, 3) exhibit acute psychosis, 4) have a diagnosis of borderline personality disorder, or 5) have prior experience of MBCT. Our primary outcome is the frequency and medical severity of NSSI. As secondary outcomes we will assess changes in rumination, mindfulness, emotion regulation, distress tolerance, stress, and attentional bias, and test these as mechanisms of change. Discussion: This is the first randomised controlled trial to test the efficacy of MBCT in reducing NSSI. Evidence of the efficacy of MBCT for self-injury will allow provision of a brief intervention for self-injury that can be implemented as a stand-alone treatment or integrated with existing treatments for psychiatric disorders
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