924 research outputs found

    Temporal markers of prosodic boundaries in children's speech production

    Get PDF
    It is often thought that the ability to use prosodic features accurately is mastered in early childhood. However, research to date has produced conflicting evidence, notably about the development of children's ability to mark prosodic boundaries. This paper investigates (i) whether, by the age of eight, children use temporal boundary features in their speech in a systematic way, and (ii) to what extent adult listeners are able to interpret their production accurately and unambiguously. The material consists of minimal pairs of utterances: one utterance includes a compound noun, in which there is no prosodic boundary after the first noun, e.g. ‘coffee-cake and tea’, while the other utterance includes simple nouns, separated by a prosodic boundary, e.g. ‘coffee, cake and tea’. Ten eight-year-old children took part, and their productions were rated by 23 adult listeners. Two phonetic exponents of prosodic boundaries were analysed: pause duration and phrase-final lengthening. The results suggest that, at the age of 8, there is considerable variability among children in their ability to mark phrase boundaries of the kind analysed in the experiment, with some children failing to differentiate between the members of the minimal pairs reliably. The differences between the children in their use of boundary features were reflected in the adults' perceptual judgements. Both temporal cues to prosodic boundaries significantly affected the perceptual ratings, with pause being a more salient determinant of ratings than phrase-final lengthening

    Investigating the value of radiomics stemming from DSC quantitative biomarkers in IDH mutation prediction in gliomas

    Get PDF
    Objective: This study aims to assess the value of biomarker based radiomics to predict IDH mutation in gliomas. The patient cohort consists of 160 patients histopathologicaly proven of primary glioma (WHO grades 2–4) from 3 different centers. Methods: To quantify the DSC perfusion signal two different mathematical modeling methods were used (Gamma fitting, leakage correction algorithms) considering the assumptions about the compartments contributing in the blood flow between the extra- and intra vascular space. Results: The Mean slope of increase (MSI) and the K1 parameter of the bidirectional exchange model exhibited the highest performance with (ACC 74.3% AUROC 74.2%) and (ACC 75% AUROC 70.5%) respectively. Conclusion: The proposed framework on DSC-MRI radiogenomics in gliomas has the potential of becoming a reliable diagnostic support tool exploiting the mathematical modeling of the DSC signal to characterize IDH mutation status through a more reproducible and standardized signal analysis scheme for facilitating clinical translation

    Systematic review and meta-analysis of clinical effectiveness of self-management interventions in Parkinson’s disease

    Get PDF
    BACKGROUND: Parkinson's disease is a complex neurodegenerative condition with significant impact on quality of life (QoL), wellbeing and function. The objective of this review is to evaluate the clinical effectiveness of self-management interventions for people with Parkinson's disease, taking a broad view of self-management and considering effects on QoL, wellbeing and function. METHODS: Systematic searches of four databases (MEDLINE, Embase, PsycINFO, Web of Science) were conducted for studies evaluating self-management interventions for people with Parkinson's disease published up to 16th November 2020. Original quantitative studies of adults with idiopathic Parkinson's disease were included, whilst studies of atypical Parkinsonism were excluded. Full-text articles were independently assessed by two reviewers, with data extracted by one reviewer and reliability checked by a second reviewer, then synthesised through a narrative approach and, for sufficiently similar studies, a meta-analysis of effect size was conducted (using a random-effects meta-analysis with restricted maximum likelihood method pooled estimate). Interventions were subdivided into self-management components according to PRISMS Taxonomy. Risk of bias was examined with the Cochrane Risk of Bias 2 (RoB2) tool or ROBIN-I tool as appropriate. RESULTS: Thirty-six studies were included, evaluating a diverse array of interventions and encompassing a range of study designs (RCT n = 19; non-randomised CT n = five; within subject pre- and post-intervention comparisons n = 12). A total of 2884 participants were assessed in studies across ten countries, with greatest output from North America (14 studies) and UK (six studies). Risk of bias was moderate to high for the majority of studies, mostly due to lack of participant blinding, which is not often practical for interventions of this nature. Only four studies reported statistically significant improvements in QoL, wellbeing or functional outcomes for the intervention compared to controls. These interventions were group-based self-management education and training programmes, either alone, combined with multi-disciplinary rehabilitation, or combined with Cognitive Behaviour Therapy; and a self-guided community-based exercise programme. Four of the RCTs evaluated sufficiently similar interventions and outcomes for meta-analysis: these were studies of self-management education and training programmes evaluating QoL (n = 478). Meta-analysis demonstrated no significant difference between the self-management and the control groups with a standardised mean difference (Hedges g) of - 0.17 (- 0.56, 0.21) p = 0.38. By the GRADE approach, the quality of this evidence was deemed "very low" and the effect of the intervention is therefore uncertain. Components more frequently observed in effective interventions, as per PRISMS taxonomy analysis, were: information about resources; training or rehearsing psychological strategies; social support; and lifestyle advice and support. The applicability of these findings is weakened by the ambiguous and at times overlapping nature of self-management components. CONCLUSION: Approaches and outcomes to self-management interventions in Parkinson's disease are heterogenous. There are insufficient high quality RCTs in this field to show effectiveness of self-management interventions in Parkinson's disease. Whilst it is not possible to draw conclusions on specific intervention components that convey effectiveness, there are promising findings from some studies, which could be targeted in future evaluations

    Cellular targets of nitric oxide in the hippocampus.

    Get PDF
    In the hippocampus, as in many other CNS areas, nitric oxide (NO) participates in synaptic plasticity, manifested as changes in pre- and/or postsynaptic function. While it is known that these changes are brought about by cGMP following activation of guanylyl cyclase-coupled NO receptors attempts to locate cGMP by immunocytochemistry in hippocampal slices in response to NO have failed to detect the cGMP elevation where expected, i.e. in the pyramidal neurones. Instead, astrocytes, unidentified varicose fibres and GABA-ergic nerve terminals are reported to be the prominent NO targets, raising the possibility that NO acts indirectly via other cells. We have re-investigated the distribution of cGMP generated in response to endogenous and exogenous NO in hippocampal slices using immunohistochemistry and new conditions designed to optimise cGMP accumulation and, hence, its detectability. The conditions included use of tissue from the developing rat hippocampus, a potent inhibitor of phosphodiesterase-2, and an allosteric enhancer of the NO-receptive guanylyl cyclase. Under these conditions, cGMP was formed in response to endogenous NO and was found in a population of pyramidal cell somata in area CA3 and subiculum as well as in structures described previously. The additional presence of exogenous NO resulted in hippocampal cGMP reaching the highest level recorded for brain tissue (1700 pmol/mg protein) and in cGMP immunolabelling throughout the pyramidal cell layer. Populations of axons and interneurones were also stained. According with these results, immunohistochemistry for the common NO receptor β1-subunit indicated widespread expression. A similar staining pattern for the α1-subunit with an antibody used previously in the hippocampus and elsewhere, however, proved to be artefactual. The results indicate that the targets of NO in the hippocampus are more varied and extensive than previous evidence had suggested and, in particular, that the pyramidal neurones participating in NO-dependent synaptic plasticity are direct NO targets

    On the selectivity of neuronal NOS inhibitors.

    Get PDF
    Isoform-selective inhibitors of NOS enzymes are desirable as research tools and for potential therapeutic purposes. Vinyl-l-N-5-(1-imino-3-butenyl)-l-ornithine (l-VNIO) and N(ω) -propyl-l-arginine (NPA) purportedly have good selectivity for neuronal over endothelial NOS under cell-free conditions, as does N-[(3-aminomethyl)benzyl]acetamidine (1400W), which is primarily an inducible NOS inhibitor. Although used in numerous investigations in vitro and in vivo, there have been surprisingly few tests of the potency and selectivity of these compounds in cells. This study addresses this deficiency and evaluates the activity of new and potentially better pyrrolidine-based compounds

    Health Care Professionals’ perspectives on self-management for people with Parkinson’s: qualitative findings from a UK study

    Get PDF
    Background: Parkinson’s disease is a long-term, complex health condition. To improve or maintain quality of life, people with Parkinson’s can have an active involvement in their care through self-management techniques. Given the complexity and individualization of self-management, people with Parkinson’s will need support and encouragement from their healthcare professionals (HCPs). Despite the key role HCPs have in this, research has seldom explored their perspectives and understanding of self-management for people with Parkinson’s. Methods: Multi-disciplinary teams providing care for people with Parkinson’s across London, Coventry and Hertfordshire were approached and took part in either one of four focus groups or individual interviews. Forty-two HCPs, including a range of specialist doctors, general practitioners, allied health professionals, nurses, and social workers, took part in this study. Interviews were transcribed and analysed using thematic analysis to identify themes. Results: Four themes were developed from the data: 1) Empowerment of patients through holistic care and being person-centred; 2) Maximising motivation and capability for patients, for example using asset based approaches and increasing opportunities; 3) importance of empowerment of carers to support selfmanagement and 4) contextual barriers to self-management such as the social context. Conclusions: This study is the first to explore the perspectives of HCPs on self-management in people with Parkinson’s. Our findings have identified important considerations surrounding empowerment, motivation, carers and contextual barriers to better understand how we enable effective selfmanagement techniques in people with Parkinson’s. Research should build on these findings on to develop acceptable and effective self-management tools for use in practice with people affected by Parkinson’s

    Cirsium species show disparity in patterns of genetic variation at their range-edge, despite similar patterns of reproduction and isolation

    Get PDF
    Genetic variation was assessed across the UK geographical range of Cirsium acaule and Cirsium heterophyllum. A decline in genetic diversity and increase in population divergence approaching the range edge of these species was predicted based on parallel declines in population density and seed production reported seperately. Patterns were compared with UK populations of the widespread Cirsium arvense.Populations were sampled along a latitudinal transect in the UK and genetic variation assessed using microsatellite markers. Cirsium acaule shows strong isolation by distance, a significant decline in diversity and an increase in divergence among range-edge populations. Geographical structure is also evident in C. arvense, whereas no such patterns are seen in C.heterophyllum. There is a major disparity between patterns of genetic variation in C. acaule and C. heterophyllum despite very similar patterns in seed production and population isolation in these species. This suggests it may be misleading to make assumptions about the geographical structure of genetic variation within species based solely on the present-day reproduction and distribution of populations

    Illusions and Delusions: Relating Experimentally-Induced False Memories to Anomalous Experiences and Ideas

    Get PDF
    The salience hypothesis of psychosis rests on a simple but profound observation that subtle alterations in the way that we perceive and experience stimuli have important consequences for how important these stimuli become for us, how much they draw our attention, how they embed themselves in our memory and, ultimately, how they shape our beliefs. We put forward the idea that a classical memory illusion – the Deese–Roediger–McDermott (DRM) effect – offers a useful way of exploring processes related to such aberrant belief formation. The illusion occurs when, as a consequence of its relationship to previous stimuli, a stimulus that has not previously been presented is falsely remembered. Such illusory familiarity is thought to be generated by the surprising fluency with which the stimulus is processed. In this respect, the illusion relates directly to the salience hypothesis and may share common cognitive underpinnings with aberrations of perception and attribution that are found in psychosis. In this paper, we explore the theoretical importance of this experimentally-induced illusion in relation to the salience model of psychosis. We present data showing that, in healthy volunteers, the illusion relates directly to self reported anomalies of experience and magical thinking. We discuss this finding in terms of the salience hypothesis and of a broader Bayesian framework of perception and cognition which emphasizes the salience both of predictable and unpredictable experiences

    A preliminary investigation of the use of inertial sensing technology for the measurement of hip rotation asymmetry in horse riders

    Get PDF
    This study investigated the use of inertial sensing technology as an indicator of asymmetry in horse riders, evidenced by discrepancies in the angle of external rotation of the hip joint. Twelve horse and rider combinations were assessed with the rider wearing the XsensTM MVN inertial motion capture suit. Asymmetry (left vs right) was revealed in mean hip external rotation of all riders, with values ranging from 1° to 27°, and 83% showed greater external rotation of the right hip. This study represents novel use of inertial sensing equipment in its application to the measurement of rider motion patterns. The technique is non-invasive, is capable of recording rider hip rotation asymmetry whilst performing a range of movements unhindered and was found to be efficient and practical, with potential to further advance the analysis of horse and rider interactions
    corecore