1,267 research outputs found

    Detecting event-related recurrences by symbolic analysis: Applications to human language processing

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    Quasistationarity is ubiquitous in complex dynamical systems. In brain dynamics there is ample evidence that event-related potentials reflect such quasistationary states. In order to detect them from time series, several segmentation techniques have been proposed. In this study we elaborate a recent approach for detecting quasistationary states as recurrence domains by means of recurrence analysis and subsequent symbolisation methods. As a result, recurrence domains are obtained as partition cells that can be further aligned and unified for different realisations. We address two pertinent problems of contemporary recurrence analysis and present possible solutions for them.Comment: 24 pages, 6 figures. Draft version to appear in Proc Royal Soc

    Childhood maltreatment and the medical morbidity in bipolar disorder: a case-control study.

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    BACKGROUND: Childhood maltreatment (abuse and neglect) can have long-term deleterious consequences, including increased risk for medical and psychiatric illnesses, such as bipolar disorder in adulthood. Emerging evidence suggests that a history of childhood maltreatment is linked to the comorbidity between medical illnesses and mood disorders. However, existing studies on bipolar disorder have not yet explored the specific influence of child neglect and have not included comparisons with individuals without mood disorders (controls). This study aimed to extend the existing literature by examining the differential influence of child abuse and child neglect on medical morbidity in a sample of bipolar cases and controls. METHODS: The study included 72 participants with bipolar disorder and 354 psychiatrically healthy controls (average age of both groups was 48 years), who completed the Childhood Trauma Questionnaire, and were interviewed regarding various medical disorders. RESULTS: A history of any type of childhood maltreatment was significantly associated with a diagnosis of any medical illness (adjusted OR = 6.28, 95% confidence intervals 1.70-23.12, p = 0.006) and an increased number of medical illnesses (adjusted OR = 3.77, 95% confidence intervals 1.34-10.57, p = 0.012) among adults with bipolar disorder. Exposure to child abuse was more strongly associated with medical disorders than child neglect. No association between childhood maltreatment and medical morbidity was detected among controls. CONCLUSIONS: To summarise, individuals with bipolar disorder who reported experiencing maltreatment during childhood, especially abuse, were at increased risk of suffering from medical illnesses and warrant greater clinical attention.The bipolar case–control genetic association study was funded by an unrestricted grant from GlaxoSmithKline Research and Development. Funding for the depression case–control study was provided by the UK Medical Research Council (MRC; G0701420). The BADGE study was supported by an Interdisciplinary Ph.D. studentship from the UK Economic Social Research Council (ESRC) and MRC to Dr. Hosang. Prof. Uher is supported by the Canada Research Chairs program (http://www.chairs-chaires.gc.ca/him) and Dr. Fisher is supported by an MQ Fellows Award (MQ14F40). The sources of funding had no involvement in the study design, data collection or decision to submit for publication

    Reminiscence therapy for dementia

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    BACKGROUND: This updated Cochrane Review of reminiscence therapy (RT) for dementia was first published in 1998, and last updated in 2005. RT involves the discussion of memories and past experiences with other people using tangible prompts such as photographs or music to evoke memories and stimulate conversation. RT is implemented widely in a range of settings using a variety of formats. OBJECTIVES: To assess the effects of RT on people living with dementia and their carers, taking into account differences in its implementation, including setting (care home, community) and modality (group, individual). SEARCH METHODS: We searched ALOIS (the Cochrane Dementia and Cognitive Improvement Group's Specialized Register) on 6 April 2017 using the search term 'reminiscence.' SELECTION CRITERIA: We included all randomised controlled trials of RT for dementia in which the duration of the intervention was at least four weeks (or six sessions) and that had a 'no treatment' or passive control group. Outcomes of interest were quality of life (QoL), cognition, communication, behaviour, mood and carer outcomes. DATA COLLECTION AND ANALYSIS: Two authors (LOP and EF) independently extracted data and assessed risk of bias. Where necessary, we contacted study authors for additional information. We pooled data from all sufficiently similar studies reporting on each outcome. We undertook subgroup analysis by setting (community versus care home) and by modality (individual versus group). We used GRADE methods to assess the overall quality of evidence for each outcome. MAIN RESULTS: We included 22 studies involving 1972 people with dementia. Meta-analyses included data from 16 studies (1749 participants). Apart from six studies with risk of selection bias, the overall risk of bias in the studies was low.Overall, moderate quality evidence indicated RT did not have an important effect on QoL immediately after the intervention period compared with no treatment (standardised mean difference (SMD) 0.11, 95% confidence interval (CI) -0.12 to 0.33; I2= 59%; 8 studies; 1060 participants). Inconsistency between studies mainly related to the study setting. There was probably a slight benefit in favour of RT in care homes post-treatment (SMD 0.46, 95% CI 0.18 to 0.75; 3 studies; 193 participants), but little or no difference in QoL in community settings (867 participants from five studies).For cognitive measures, there was high quality evidence for a very small benefit, of doubtful clinical importance, associated with reminiscence at the end of treatment (SMD 0.11, 95% CI 0.00 to 0.23; 14 studies; 1219 participants), but little or no difference at longer-term follow-up. There was a probable slight improvement for individual reminiscence and for care homes when analysed separately, but little or no difference for community settings or for group studies. Nine studies included the widely used Mini-Mental State Examination (MMSE) as a cognitive measure, and, on this scale, there was high quality evidence for an improvement at the end of treatment (mean difference (MD) 1.87 points, 95% CI 0.54 to 3.20; 437 participants). There was a similar effect at longer-term follow-up, but the quality of evidence for this analysis was low (1.8 points, 95% CI -0.06 to 3.65).For communication measures, there may have been a benefit of RT at the end of treatment (SMD -0.51 points, 95% CI -0.97 to -0.05; I2= 62%; negative scores indicated improvement; 6 studies; 249 participants), but there was inconsistency between studies, related to the RT modality. At follow-up, there was probably a slight benefit of RT (SMD -0.49 points, 95% CI -0.77 to -0.21; 4 studies; 204 participants). Effects were uncertain for individual RT, with very low quality evidence available. For reminiscence groups, evidence of moderate quality indicated a probable slight benefit immediately (SMD -0.39, 95% CI -0.71 to -0.06; 4 studies; 153 participants), and at later follow-up. Community participants probably benefited at end of treatment and follow-up. For care home participants, the results were inconsistent between studies and, while there may be an improvement at follow-up, at the end of treatment the evidence quality was very low and effects were uncertain.Other outcome domains examined for people with dementia included mood, functioning in daily activities, agitation/irritability and relationship quality. There were no clear effects in these domains. Individual reminiscence was probably associated with a slight benefit on depression scales, although its clinical importance was uncertain (SMD -0.41, 95% CI -0.76 to -0.06; 4 studies; 131 participants). We found no evidence of any harmful effects on people with dementia.We also looked at outcomes for carers, including stress, mood and quality of relationship with the person with dementia (from the carer's perspective). We found no evidence of effects on carers other than a potential adverse outcome related to carer anxiety at longer-term follow-up, based on two studies that had involved the carer jointly in reminiscence groups with people with dementia. The control group carers were probably slightly less anxious (MD 0.56 points, 95% CI -0.17 to 1.30; 464 participants), but this result is of uncertain clinical importance, and is also consistent with little or no effect. AUTHORS' CONCLUSIONS: The effects of reminiscence interventions are inconsistent, often small in size and can differ considerably across settings and modalities. RT has some positive effects on people with dementia in the domains of QoL, cognition, communication and mood. Care home studies show the widest range of benefits, including QoL, cognition and communication (at follow-up). Individual RT is associated with probable benefits for cognition and mood. Group RT and a community setting are associated with probable improvements in communication. The wide range of RT interventions across studies makes comparisons and evaluation of relative benefits difficult. Treatment protocols are not described in sufficient detail in many publications. There have been welcome improvements in the quality of research on RT since the previous version of this review, although there still remains a need for more randomised controlled trials following clear, detailed treatment protocols, especially allowing the effects of simple and integrative RT to be compared

    Monotonicity of Fitness Landscapes and Mutation Rate Control

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    A common view in evolutionary biology is that mutation rates are minimised. However, studies in combinatorial optimisation and search have shown a clear advantage of using variable mutation rates as a control parameter to optimise the performance of evolutionary algorithms. Much biological theory in this area is based on Ronald Fisher's work, who used Euclidean geometry to study the relation between mutation size and expected fitness of the offspring in infinite phenotypic spaces. Here we reconsider this theory based on the alternative geometry of discrete and finite spaces of DNA sequences. First, we consider the geometric case of fitness being isomorphic to distance from an optimum, and show how problems of optimal mutation rate control can be solved exactly or approximately depending on additional constraints of the problem. Then we consider the general case of fitness communicating only partial information about the distance. We define weak monotonicity of fitness landscapes and prove that this property holds in all landscapes that are continuous and open at the optimum. This theoretical result motivates our hypothesis that optimal mutation rate functions in such landscapes will increase when fitness decreases in some neighbourhood of an optimum, resembling the control functions derived in the geometric case. We test this hypothesis experimentally by analysing approximately optimal mutation rate control functions in 115 complete landscapes of binding scores between DNA sequences and transcription factors. Our findings support the hypothesis and find that the increase of mutation rate is more rapid in landscapes that are less monotonic (more rugged). We discuss the relevance of these findings to living organisms

    Developing the content of two behavioural interventions : using theory-based interventions to promote GP management of upper respiratory tract infection without prescribing antibiotics #1

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    Background: Evidence shows that antibiotics have limited effectiveness in the management of upper respiratory tract infection (URTI) yet GPs continue to prescribe antibiotics. Implementation research does not currently provide a strong evidence base to guide the choice of interventions to promote the uptake of such evidence-based practice by health professionals. While systematic reviews demonstrate that interventions to change clinical practice can be effective, heterogeneity between studies hinders generalisation to routine practice. Psychological models of behaviour change that have been used successfully to predict variation in behaviour in the general population can also predict the clinical behaviour of healthcare professionals. The purpose of this study was to design two theoretically-based interventions to promote the management of upper respiratory tract infection (URTI) without prescribing antibiotics. Method: Interventions were developed using a systematic, empirically informed approach in which we: selected theoretical frameworks; identified modifiable behavioural antecedents that predicted GPs intended and actual management of URTI; mapped these target antecedents on to evidence-based behaviour change techniques; and operationalised intervention components in a format suitable for delivery by postal questionnaire. Results: We identified two psychological constructs that predicted GP management of URTI: "Self-efficacy," representing belief in one's capabilities, and "Anticipated consequences," representing beliefs about the consequences of one's actions. Behavioural techniques known to be effective in changing these beliefs were used in the design of two paper-based, interactive interventions. Intervention 1 targeted self-efficacy and required GPs to consider progressively more difficult situations in a "graded task" and to develop an "action plan" of what to do when next presented with one of these situations. Intervention 2 targeted anticipated consequences and required GPs to respond to a "persuasive communication" containing a series of pictures representing the consequences of managing URTI with and without antibiotics. Conclusion: It is feasible to systematically develop theoretically-based interventions to change professional practice. Two interventions were designed that differentially target generalisable constructs predictive of GP management of URTI. Our detailed and scientific rationale for the choice and design of our interventions will provide a basis for understanding any effects identified in their evaluation. Trial registration: Clinicaltrials.gov NCT00376142This study is funded by the European Commission Research Directorate as part of a multi-partner program: Research Based Education and Quality Improvement (ReBEQI): A Framework and tools to develop effective quality improvement programs in European healthcare. (Proposal No: QLRT-2001-00657)

    Translating clinicians' beliefs into implementation interventions (TRACII) : a protocol for an intervention modeling experiment to change clinicians' intentions to implement evidence-based practice

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    Background: Biomedical research constantly produces new findings, but these are not routinely incorporated into health care practice. Currently, a range of interventions to promote the uptake of emerging evidence are available. While their effectiveness has been tested in pragmatic trials, these do not form a basis from which to generalise to routine care settings. Implementation research is the scientific study of methods to promote the uptake of research findings, and hence to reduce inappropriate care. As clinical practice is a form of human behaviour, theories of human behaviour that have proved to be useful in other settings offer a basis for developing a scientific rationale for the choice of interventions. Aims: The aims of this protocol are 1) to develop interventions to change beliefs that have already been identified as antecedents to antibiotic prescribing for sore throats, and 2) to experimentally evaluate these interventions to identify those that have the largest impact on behavioural intention and behavioural simulation. Design: The clinical focus for this work will be the management of uncomplicated sore throat in general practice. Symptoms of upper respiratory tract infections are common presenting features in primary care. They are frequently treated with antibiotics, and research evidence is clear that antibiotic treatment offers little or no benefit to otherwise healthy adult patients. Reducing antibiotic prescribing in the community by the "prudent" use of antibiotics is seen as one way to slow the rise in antibiotic resistance, and appears safe, at least in children. However, our understanding of how to do this is limited. Participants will be general medical practitioners. Two theory-based interventions will be designed to address the discriminant beliefs in the prescribing of antibiotics for sore throat, using empirically derived resources. The interventions will be evaluated in a 2 × 2 factorial randomised controlled trial delivered in a postal questionnaire survey. Two outcome measures will be assessed: behavioural intention and behavioural simulation.This study is funded by the European Commission Research Directorate as part of a multi-partner program: Research Based Education and Quality Improvement (ReBEQI): A Framework and tools to develop effective quality improvement programs in European healthcare. (Proposal No: QLRT-2001-00657)

    Recognition of cancer warning signs and anticipated time to help-seeking in a population sample of adults in the UK

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    Background: Not recognising a symptom as suspicious is a common reason given by cancer patients for delayed help-seeking; but inevitably this is retrospective. We therefore investigated associations between recognition of warning signs for breast, colorectal and lung cancer and anticipated time to help-seeking for symptoms of each cancer. Methods: Computer-assisted telephone interviews were conducted with a population-representative sample (N=6965) of UK adults age greater than or equal to50 years, using the Awareness and Beliefs about Cancer scale. Anticipated time to help-seeking for persistent cough, rectal bleeding and breast changes was categorised as >2 vs less than or equal to2 weeks. Recognition of persistent cough, unexplained bleeding and unexplained lump as cancer warning signs was assessed (yes/no). Associations between recognition and help-seeking were examined for each symptom controlling for demographics and perceived ease of health-care access. Results: For each symptom, the odds of waiting for >2 weeks were significantly increased in those who did not recognise the related warning sign: breast changes: OR=2.45, 95% CI 1.47–4.08; rectal bleeding: OR=1.77, 1.36–2.30; persistent cough: OR=1.30, 1.17–1.46, independent of demographics and health-care access. Conclusion: Recognition of warning signs was associated with anticipating faster help-seeking for potential symptoms of cancer. Strategies to improve recognition are likely to facilitate earlier diagnosis
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