Characterising & classifying the local population of ultracool dwarfs with Gaia DR2 and EDR3

Ultracool dwarfs (UCDs) are the lowest mass products of star formation and span the end of the stellar main sequence from very-low mass, hydrogen-burning M stars to the coolest brown dwarfs. In this thesis we characterise and classify the ultracool dwarf population in the solar neighbourhood using the accuracy and precision of data from the Gaia space observatory. Combining astrometric (in particular parallax) and photometric data from Gaia DR2 and EDR3 with photometry from UKIDSS, SDSS and 2MASS, we prepare some of the largest and most accurate, near-100% complete volume-limited populations of nearby, field late-M, L and T dwarfs. From these samples we derive key population characteristics such as colour-absolute magnitude relationships, the stellar luminosity function, the binary fraction and the binary mass ratio. Our statistical-based approach differs from much of the UCD literature to date which seeks to prepare meta-catalogues from disparate surveys and individual spectroscopic observations with distance determined by indirect methods. Our approach offers improvements in scale, completeness, and distance accuracy. In particular we use Gaia to update the colour-magnitude relations and derive the stellar luminosity functions in MJ and MG of the UCDs. We calculate the binary fraction of the late-M and early-L dwarfs as a function of spectral type by carefully modelling the over-luminous unresolved binary population and show that late-M dwarf binaries reside almost exclusively in equal-mass pairs or twins. Given the complex spectral features of UCDs, consistent and accurate classification is challenging. We investigate the current traditional methods of classification and evaluate a range of alternative techniques including supervised and unsupervised machine learning. In a separate study we use Gaia data to prepare a large, cylindrical sample of FGK main sequence dwarf stars to calculate the structure of the vertical density distribution close to the galactic plane, in fine detail, as a function of colour. Using our derived colour-dependent thin disk scale height we directly determine the star formation history of the solar neighbourhood by modelling the evolution of stellar populations using state-of-the-art PARSEC isochrones.Open Acces

Recovery after psychosis: a compassion focused recovery approach to psychosis in a forensic mental health setting

Over the past fifty years, there has been significant improvement in the expected outcomes of individuals with psychosis, due to advances in psychotropic medication, and through the development and application of psychological approaches such as Cognitive Behavioural Therapy. Such improvements in outcome have been demonstrated through various outcome studies and meta-analyses of outcome studies. However, the recovery/consumer movement has criticised outcome studies on the basis that they focus on symptomatic outcome and do not incorporate into their studies measures of outcome as defined by individuals who experience psychosis. The aim of this thesis was therefore to explore the experiences of individuals with psychosis in a forensic mental health setting. The objective was to develop recovery focused psychological interventions based on patients’ experiences of what helped them to cope in hospital, and in essence, what they valued in their recovery. The first study employed a social constructionist version of grounded theory methodology to explore the experiences of patients residing in a secure hospital. Thirteen individuals who had experience of psychosis were interviewed in depth about their experiences of recovery. Contrasting accounts of recovery were apparent from the way in which participants spoke about their experiences. Some participants gave rich and reflective accounts of their recovery. These participants spoke about the nature of their past experiences, the importance of those experiences in contextualising their problems and reflected on the implications of this on the tasks of recovery. In contrast, other participants’ transcripts tended to be short and unelaborated. Recovery tasks seemed to be segregated from previous experiences and their reflection on their experience of psychosis seemed minimised. All participants spoke about the importance of developing their sense of self, and the importance of developing relationships with staff and with family. This study is presented in Chapter Four. The findings of the grounded theory study led to the development of a self-esteem intervention. Research has shown that low self-esteem is common in individuals with psychosis (Bowins & Shugar, 1998; Silverstone, 1991), and that it is implicated in the development and maintenance of psychotic experiences such as delusions and auditory hallucinations (Garety et al., 2001; Smith et al., 2006). This intervention was based on a previous study carried out by Hall and Tarrier (2003), but adapted for delivery in a group setting in a secure hospital. Fifteen patients completed the self-esteem group intervention and significant improvements were found on self-esteem and depression. These improvements were maintained over a three month-follow up period. This study is reported in detail in Chapter Five. A recovery group was developed after this. The modules in this programme were developed from the themes of the grounded theory study and the observations made during the self-esteem programme. The recovery group was based on Compassion Focused Therapy (CFT, see below) and aimed to promote emotional recovery with the aim of improving self-soothing, coping with distress and the development of inner warmth. This programme was developed following observations that although individuals in the self-esteem group could challenge self-critical thoughts through the use of skills they had acquired in the group, they reported that they continued to feel negative and worthless about themselves. Compassion Focused Therapy (CFT) was developed by Gilbert and colleagues (Gilbert, 1992, 1997, 2000; Gilbert and Irons, 2005) for individuals with shame and self-critical and attacking thoughts. It is based on social mentality theory (Gilbert, 1989, 2001, 2005), which explains how people come to experience an internalised self-attacking narrative. This often develops as a result of trauma, abuse and loss and results in an individual experiencing shame and feeling a sense of threat. It also has implications for an individual’s ability to cope with distress and to regulate affect. The purpose of CMT is therefore to help individuals move from a self-attacking style to one of self-soothing and compassion. It is anticipated that this style of self-relating will promote recovery and enable individuals to be less critical about themselves and their experiences and so, be able to seek help should they face relapse in the future. With this in mind, the Recovery After Psychosis (RAP) programme was piloted and eighteen individuals completed the group. Significant effects were found for depression, self-esteem and an improvement in sense of self compared to others. This study is discussed in Chapter Six. The findings of the studies contained within this thesis are further discussed in Chapter seven. The findings are compared with previous studies on recovery, and also compared with other interventions employing compassion-focused approaches. The limitations of the research in this thesis are discussed. A model of compassion focused service delivery is described along with implications for future clinical practice and research

The local vertical density distribution of ultracool dwarfs M7 to L2.5 and their luminosity function

We investigate the form of the local vertical density profile of the stars in the Galactic disk, close to the Galactic plane. We use a homogeneous sample of 34000 ultracool dwarfs M7 to L2.5 that all lie within 350 pc of the plane. We fit a profile of the form sech\textsuperscript\alpha, where α=2 is the theoretically preferred isothermal profile and α=0 is the exponential function. Larger values of α correspond to greater flattening of the profile towards the plane. We employ a likelihood analysis that accounts in a direct way for unresolved binaries in the sample, as well as for the spread in absolute magnitude 2$M_J$ within each spectral sub-type (Malmquist bias). We measure α=0.29 $\frac{+0.12}{-0.13}$. The α=1 (sech) and flatter profiles are ruled out at high confidence for this sample, while α=0 (exponential) is included in the 95% credible interval. Any flattening relative to exponential is modest, and is confined to within 50 pc of the plane. The measured value of α is consistent with the results of the recent analysis by Xiang et al. Our value for α is also similar to that determined for nearby spiral galaxies by de Grijs et al., measured from photometry of galaxies viewed edge on. The measured profile allows an accurate determination of the local space density of ultracool dwarfs M7 to L2.5, and we use this to make a new determination of the luminosity function at the bottom of the main sequence. Our results for the luminosity function are a factor two to three lower than the recent measurement by Bardalez Gagliuffi et al., that uses stars in the local 25 pc radius bubble, but agree well with the older study by Cruz et al

A consensus building exercise to determine research priorities for silver trauma

Background Emergency care research into ‘Silver Trauma’, which is simply defined as major trauma consequent upon relatively minor injury mechanisms, is facing many challenges including that at present, there is no clear prioritisation of the issues. This study aimed to determine the top research priorities to guide future research. Methods This consensus-based prioritization exercise used a three-stage modified Delphi technique. The study consisted of an idea generating (divergent) first round, a ranking evaluation in the second round, and a (convergent) consensus meeting in the third round. Results A total of 20 research questions advanced to the final round of this study. After discussing the importance and clinical significance of each research question, five research questions were prioritised by the experts; the top three research priorities were: (1). What are older people’s preferred goals of trauma care? (2). Beyond the Emergency Department (ED), what is the appropriate combined geriatric and trauma care? (3). Do older adults benefit from access to trauma centres? If so, do older trauma patients have equitable access to trauma centre compared to younger adults? Conclusion The results of this study will assist clinicians, researchers, and organisations that are interested in silver trauma in guiding their future efforts and funding toward addressing the identified research priorities

Cognitive behaviour therapy for psychosis in high secure services: An exploratory hermeneutic review of the international literature

Background: Mainstream psychological interventions may need adaptation in High Secure (HS) healthcare contexts to enable better recovery, safeguard the public and offer economic value. One specific psychological intervention, cognitive behavioural therapy for psychosis (CBTp), has an already proven efficacy in aiding recovery in non-forensic populations, yet its impact in HS settings has received considerably less research attention. Aims: This exploratory review catalogues CBTp approaches used in HS hospitals and appraises impact through the inclusion of both fugitive literature and peer reviewed research. Method: A pragmatic approach was utilized through an iterative literature search strategy and hermeneutic source analysis of the identified studies. Results: Fourteen studies were identified from HS contexts from within the UK and internationally. These included group, individual therapy and CBTp linked milieus. Conclusions: CBTp is an active component of treatment in HS contexts. Some modes of delivery seem to have greater levels of efficacy with more typical HS patients. The literature indicates key differences between HS and non-HS applied CBTp. Continued application and evaluation of CBTp in HS conditions is warranted

Do therapeutic imagery practices affect physiological and emotional indicators of threat in high self-critics?

Objectives: Imagery is known to be a powerful means of stimulating various physiological processes and is increasingly used within standard psychological therapies. Compassion-focused imagery (CFI) has been used to stimulate affiliative emotion in people with mental health problems. However, evidence suggests that self-critical individuals may have particular difficulties in this domain with single trials. The aim of the present study was to further investigate the role of self-criticism in responsiveness to CFI by specifically pre-selecting participants based on trait self-criticism. Design: Using the Forms of Self-Criticism/Self-Reassuring Scale, 29 individuals from a total sample of 139 were pre-selected to determine how self-criticism impacts upon an initial instance of imagery. Methods: All participants took part in three activities: a control imagery intervention (useable data N = 25), a standard CFI intervention (useable data N = 25), and a non-intervention control (useable data N = 24). Physiological measurements (alpha amylase) as well as questionnaire measures of emotional responding (i.e., the Positive and Negative Affect Schedule, the Types of Positive Affect Scale, and the State Adult Attachment Scale) were taken before and after the different interventions. Results: Following both imagery interventions, repeated measures analyses revealed that alpha amylase increased significantly for high self-critics compared with low self-critics. High self-critics (HSC) also reported greater insecurity on entering the imagery session and more negative CFI experiences compared with low self-critics. Practitioner Points: Data demonstrate that HSC respond negatively to imagery interventions in a single trial. This highlights that imagery focused therapies (e.g., CFI) need interventions that manage fears, blocks, and resistances to the techniques, particularly in HSC. An initial instance of imagery (e.g., CFI) can be frightening for people who have a tendency to be self-critical. This research provides examples of physiological and emotional responses to imagery type therapies in high and low self-critics, and associated clinical implications. Therapists may find it helpful to be mindful that when introducing imagery based therapies, highly self-critical patients need interventions that manage fears, blocks, and resistances to the techniques

Practical compassions: repertoires of practice and compassion talk in acute mental healthcare

This article reports an exploratory study of the concept of compassion in the work of 20 mental health practitioners in a UK Midlands facility. Using notions of practice derived from phenomenology and Bourdieusian sociology and notions of emotional labour we identify two contrasting interpretive repertoires in discussions of compassion. The first, the practical compassion repertoire, evokes the practical, physical and bodily aspects of compassion. It involves organising being with patients, playing games, anticipating disruption and taking them outside for cigarettes. Practitioners described being aware that these practical, bodily activities could lead to patients ‘opening up’, disclosing their interior concerns and enabling practical, compassionate mental health work to take place. In contrast, the second, organisational repertoire, concerns organisational constraints on compassionate practice. The shortage of staff, the record-keeping and internal processes of quality control were seen as time-greedy and apt to detract from contact with patients. The findings are discussed in relation to Bourdieu and Merleau-Ponty's phenomenological accounts of practice and habit and set in context in the growing interest in placing compassion centrally in healthcare. We also explore how the exercise of compassion in the way our participants describe it can afford the more effective exercise of medical power