1,081 research outputs found

    On the dynamic tensile strength of Zirconium

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    Despite its fundamental nature, the process of dynamic tensile failure (spall) is poorly understood. Spall initiation via cracks, voids, etc, before subsequent coalesce, is known to be highly microstructure-dependant. In particular, the availability of slip planes and other methods of plastic deformation controls the onset (or lack thereof) of spall. While studies have been undertaken into the spall response of BCC and FCC materials, less attention has paid to the spall response of highly anisotropic HCP materials. Here the dynamic behaviour of zirconium is investigated via plate-impact experiments, with the aim of building on an ongoing in-house body of work investigating these highly complex materials. In particular, in this paper the effect of impact stress on spall in a commercially sourced Zr rod is considered, with apparent strain-rate softening highlighted

    The psychological therapy preferences of patients who hear voices

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    Background Voice-hearing is a common, phenomenologically diverse, experience across different mental health diagnoses. Patient preferences for psychological therapies are helpful in informing treatment commissioning and provision, especially in the context of complex and variable experiences like voice-hearing. There is, however, very limited evidence as to the psychological therapy preferences of transdiagnostic voice-hearers. Methods Three-hundred and thirty-five voice hearers were recruited from secondary care NHS mental health services across England, between 2020 and 2022. Participants completed a questionnaire battery, involving a psychological therapy preference survey. Participants ranked their preferences across categories of practical, technical and relational therapy elements. Therapy preferences were examined using non-parametric ANOVAs and the significance of pairwise comparisons between different therapy elements. Results There were significant differences in all categories of preference elements. Clear hierarchies of preference were observed in therapy location, timing, delivery, and therapy approach. Preferences were evident, albeit with less clear vertical hierarchies, for number of sessions, mode, therapist qualities, and therapy focus, tasks and outcomes. Discussion Overall, participants expressed a preference for individual, face-to-face intervention of at least nine sessions, with a highly experienced therapist and a core focus on enhancing coping strategies for voice-hearing experiences

    Lateral stress evolution in chromium sulfide cermets with varying excess chromium

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    The shock response of chromium sulfide-chromium, a cermet of potential interest as a matrix material for ballistic applications, has been investigated at two molar ratios. Using a combustion synthesis technique allowed for control of the molar ratio of the material, which was investigated under near-stoichiometric (cermet) and excess chromium (interpenetrating composite) conditions, representing chromium:sulfur molar ratios of 1.15:1 and 4:1, respectively. The compacts were investigated via the plate-impact technique, which allowed the material to be loaded under a onedimensional state of strain. Embedded manganin stress gauges were employed to monitor the temporal evolution of longitudinal and lateral components of stress in both materials. Comparison of these two components has allowed assessment of the variation of material shear strength both with impact pressure/strain-rate and time for the two molar ratio conditions. The two materials exhibited identical material strength despite variations in their excess chromium content

    Understanding the barriers to accessing symptom-specific cognitive behavior therapy (CBT) for distressing voices: reflecting on and extending the lessons learnt from the CBT for psychosis literature

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    The experience of hearing voices ('auditory hallucinations') can cause significant distress and disruption to quality of life for people with a psychosis diagnosis. Psychological therapy in the form of Cognitive Behavior Therapy for psychosis is recommended for the treatment of positive symptoms, including distressing voices, but is rarely available to patients in the UK. Cognitive Behavior Therapy for psychosis has recently evolved with the development of symptom-specific therapies that focus upon only one symptom of psychosis at a time. Preliminary findings from randomized controlled trials suggest that these symptom-specific therapies can be more effective for distressing voices than the use of broad CBT protocols, and have the potential to target voices trans-diagnostically. Whilst this literature is evolving, consideration must be given to the potential for a symptom-specific approach to overcome some of the barriers to delivery of evidence-based psychological therapies within clinical services. These barriers are discussed in relation to the UK mental health services, and we offer suggestions for future research to enhance our understanding of these barriers

    The bactericidal effect of shock waves

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    There are a variety of theories relating to the origins of life on our home planet, some of which discuss the possibility that life may have been spread via inter-planetary bodies. There have been a number of investigations into the ability of life to withstand the likely conditions generated by asteroid impact (both contained in the impactor and buried beneath the planet surface). Previously published data regarding the ability of bacteria to survive such applied shockwaves has produced conflicting conclusions. The work presented here used an established and published technique in combination with a single stage gas gun, to shock and subsequently recover Escherichia coli populations suspended in a phosphate buffered saline solution. Peak pressure across the sample region was calculated via numerical modelling. Survival data against peak sample pressure for recovered samples is presented alongside control tests. SEM micrographs of shocked samples are presented alongside control sets to highlight key differences between cells in each case

    Understanding clinician attitudes towards implementation of guided self-help cognitive behaviour therapy for those who hear distressing voices: using factor analysis to test normalisation process theory

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    Background The Normalisation Process Theory (NPT) has been used to understand the implementation of physical health care interventions. The current study aims to apply the NPT model to a secondary mental health context, and test the model using exploratory factor analysis. This study will consider the implementation of a brief cognitive behaviour therapy for psychosis (CBTp) intervention. Methods Mental health clinicians were asked to complete a NPT-based questionnaire on the implementation of a brief CBTp intervention. All clinicians had experience of either working with the target client group or were able to deliver psychological therapies. In total, 201 clinicians completed the questionnaire. Results The results of the exploratory factor analysis found partial support for the NPT model, as three of the NPT factors were extracted: (1) coherence, (2) cognitive participation, and (3) reflexive monitoring. We did not find support for the fourth NPT factor (collective action). All scales showed strong internal consistency. Secondary analysis of these factors showed clinicians to generally support the implementation of the brief CBTp intervention. Conclusions This study provides strong evidence for the validity of the three NPT factors extracted. Further research is needed to determine whether participants’ level of seniority moderates factor extraction, whether this factor structure can be generalised to other healthcare settings, and whether pre-implementation attitudes predict actual implementation outcomes

    Do carers of adolescents at first episode psychosis have distinctive psychological needs? A pilot exploration

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    Background: Carers of patients experiencing first episode psychosis (FEP) are at an increased risk of mental and physical health problems themselves. However, little is known about how the psychological needs of carers may differ between those caring for an adolescent versus an adult who has FEP. Aims: This pilot study aimed to explore any differences in the psychological needs of carers caring for adolescents versus adults with FEP. Methods: We surveyed 254 carers of 198 FEP patients (34 carers of adolescents of 24 FEP adolescent patients). Carers completed self-report measures of anxiety, depression, burnout, subjective burden, coping, and key illness beliefs. The sample was divided according to whether the patient was under (adolescent) or over (adult) age 18, and analysed using mixed model logistic regressions. Results: Compared to the carers of adult patients, carers of adolescents were more than twice as likely (12% vs. 30%) to experience overall burnout syndrome (all three domains), and to develop it much quicker (19.4 vs. 10.1 months). They were also more likely to adopt behavioural disengagement avoidance as a form of coping. However, there was no difference between carers in terms of anxiety, depression, beliefs and subjective burden. For carers of adolescents, burnout was independently predicted by: a negative belief about the consequences of psychosis for the adolescent patient and an incoherent understanding of the patient’s mental health. Conclusions: If our findings can be replicated in a larger sample, then Rapid-Onset-Burnout-Syndrome (ROBS) is a particular problem in carers of adolescents at FEP, suggesting a need for routine screening and possible prophylactic intervention. Carers of adolescent’s use of behavioural escape coping maybe also require early intervention. Theoretically, consideration could be given to the development of an adolescent sub-branch to the cognitive model of caregiving

    Helping parents to help children overcome fear: the influence of a short video tutorial

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    Objectives Anxiety runs in families, and its transmission is largely environmental. However, studies rarely explore this process in clinically anxious parents or ask participants to face a genuine fear. We also do not know whether this process is modifiable. This study will explore these questions using a sample of clinically anxious parents. Design Experimental design comparing clinically anxious parents with non‐anxious parents, and exploring the effects of a tutorial intervention versus a control group. Methods Parents with and without anxiety disorders and their children (5–9 years) participated (N = 72). Children chose two fearful animal stimuli. Parents helped the child approach the first in graded steps. The following parental behaviours were recorded: positive/negative verbal information; positive/negative modelling; encouragement/praising of approach/avoidance behaviours. Half the parents were then randomly assigned to a short video tutorial advising how to help children cope with fearful situations. The remainder watched a control video. The approach task was repeated with the second stimulus. Results Parenting behaviours fell into two categories: ‘approach parenting’ (encouraging/praising/modelling approach; positive verbal information) and ‘avoidance parenting’ (encouraging/praising/modelling avoidance; negative verbal information). The parenting tutorial increased ‘approach parenting’ and decreased ‘avoidance parenting’ and was associated with increased child approach towards fearful stimuli. This was not moderated by parent or child anxiety. Conclusions Parenting, particularly ‘avoidance parenting’, is associated with children's approach and avoidance. A short video tutorial modified these parenting behaviours and reduced avoidance. These effects were apparent regardless of parent or child anxiety level
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