3,463 research outputs found
Varactor diode assembly with low parasitic reactances
Development of varactor diode assembly overcomes parasitic reactances of conventional varactor packages. In specially constructed assembly very high idler-frequency to signal-frequency ratios are used to obtain low-noise operation over maximum bandwidth
Integrated-circuit balanced parametric amplifier
Amplifier, fabricated on single dielectric substrate, has pair of Schottky barrier varactor diodes mounted on single semiconductor chip. Circuit includes microstrip transmission line and slot line section to conduct signals. Main features of amplifier are reduced noise output and low production cost
Exploring museum-based programmes for people living with a mild-to-moderate dementia
Museum-based programmes are recognised as having the potential to engage people with dementia (PWD) in the community and to positively impact wellbeing. However, there is a recognised lack of methodological rigour limiting the quality of the evidence-base. A systematic review is presented to better understand the psychological and social impacts of museum-based programmes specific to heritage settings for people with mild-to-moderate dementia. Themes relating to psychological outcomes comprised mood and enjoyment, subjective wellbeing, quality of life, and personhood; other key themes were cognition, engagement, and social outcomes. Quantitative measures tended to yield mixed results. There was much overlap in qualitative outcomes across studies.
To expand the evidence-base of meaningful activities for PWD in line with dementia care guidance, a mixed-methods study investigated the subjective wellbeing of PWD following small group object handling (OH) sessions in a museum. Building on previous research, the processes within sessions that may have promoted wellbeing were also explored. Wellbeing scores tentatively suggested an overall increase following OH sessions. Qualitative themes identified were scaffolding, exploring objects, agency, and group collaboration. Tentative interpretations are made around the dynamic interaction of themes and subthemes. The limitations of the study are considered, and clinical and research implications discussed
De-escalation of aggressive behaviour in healthcare settings:concept analysis
BACKGROUND: De-escalation is the recommended first-line response to potential violence and aggression in healthcare settings. Related scholarly activity has increased exponentially since the 1980s, but there is scant research about its efficacy and no guidance on what constitutes the gold standard for practice.OBJECTIVES: To clarify the concept of de-escalation of violence and aggression as described within the healthcare literature.DESIGN: Concept analysis guided by Rodgers' evolutionary approach.DATA SOURCES: Multiple nursing and healthcare databases were searched using relevant terms.REVIEW METHODS: High quality and/or highly cited, or otherwise relevant published empirical or theoretical English language literature was included. Information about surrogate terms, antecedents, attributes, consequences, and the temporal, environmental, disciplinary, and theoretical contexts of use were extracted and synthesised. Information about the specific attributes of de-escalation were subject to thematic analysis. Proposed theories or models of de-escalation were assessed against quality criteria.RESULTS: N=79 studies were included. Mental health settings were the most commonly reported environment in which de-escalation occurs, and nursing the disciplinary group most commonly discussed. Five theories of de-escalation were proposed; while each was adequate in some respects, all lacked empirical support. Based on our analysis the resulting theoretical definition of de-escalation in healthcare is "a collective term for a range of interwoven staff-delivered components comprising communication, self-regulation, assessment, actions, and safety maintenance which aims to extinguish or reduce patient aggression/agitation irrespective of its cause, and improve staff-patient relationships while eliminating or minimising coercion or restriction".CONCLUSIONS: While a number of theoretical models have been proposed, the lack of advances made in developing a robust evidence-base for the efficacy of de-escalation is striking and must, at least in part, be credited to the lack of a clear conceptualisation of the term. This concept analysis provides a framework for researchers to identify the theoretical model that they purport to use, the antecedents that their de-escalation intervention is targeting, its key attributes, and the key negative and positive consequences that are to be avoided or encouraged.</p
Systematic review of therapeutic leave in inpatient mental health services
AimTo identify, critically evaluate, and synthesise the empirical evidence about therapeutic leave from mental health inpatient settings.Background“Leave” occurs when a mental health inpatient exits the hospital ward with the appropriate authorisation alone, or accompanied by staff, family, or friends. Limited research has previously addressed therapeutic as opposed to unauthorised leave, and the evidence-base has not been systematically evaluated.DesignSystematic review methodology following relevant Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidance.Data SourcesMultiple electronic databases (CINAHL; Criminal Justice database; PsycARTICLES; Scopus; OpenGrey; Cochrane; GoogleScholar) for papers published from January 1967 to July 2017.Review MethodsInformation was extracted under the following headings: study, purpose/aims, sample, country, setting, design and data collection method(s), data collection instrument, and results. Papers were assessed, as per the hierarchy of scientific evidence, and where there was sufficient data, we calculated a range of standardised rates of leave incidence.ResultsStandardised leave rates in forensic settings reflect security level. There was little meaningful information on which to base calculation of rates for civil settings. The strongest evidence supports leave used for supervised discharge; other forms of leave lack an evidence base and decisions appear to be made on the basis of heuristic rules and unsupported assumptions. Clinical decision making about therapeutic leave cannot claim to be evidence-based.ConclusionResearch is urgently needed to provide information about how leave is managed, the best ways to support leave, and what happens on leave
The HCR-20 as a measure of reliable and clinically significant change in violence risk among secure psychiatric inpatients
Objective Periodic structured violence risk assessment is the principle method underlying treatment planning for mentally disordered offenders but little is known about how risk changes over time. We aimed to determine whether hospitalised patients underwent reliable clinical change in assessed risk. Method We used a pseudo-prospective longitudinal study design. Demographic, clinical and risk assessment data of adult inpatients (N=480) who had been routinely assessed with the HCR-20 on two to four occasions over a mean period of 17 months (SD=2) were collated. Linear mixed models regression was conducted to determine change over time on total, subscale, and individual item scores, and relative change between clinical and demographic groups. The Reliable Change Index was calculated to examine whether change was greater than that expected by measurement error; clinically significant change was defined as the extent to which HCR-20 scores reduced below previously reported scores for patients not requiring hospitalisation. Results HCR-20 total score (Estimate −0.42, 95% CI=−0.84, −0.01, p<.05; d=.20) and clinical score (Estimate=−0.42, 95% CI=−0.64, −0.20, p<.001; d=.36) reduced over assessments. Significant differences in change were evident between clinically and demographically defined groups. A maximum of 3% of individuals showed clinically significant reliable reductions in HCR-20 total scores. The scores of patients whose overall level of risk was judged to have decreased did not reduce between assessments. Conclusion Violence risk changes very little over the course of treatment although there is some variation between groups. Most change cannot be demonstrated to be reliable or clinically significant. Important clinical management decisions should not depend solely on evidence from changes in HCR-20 risk assessment
On the scaling spectrum of the Anderson impurity model
We consider the universal scaling behaviour of the Kondo resonance in the
strong coupling limit of the symmetric Anderson impurity model, using a
recently developed local moment approach. The resultant scaling spectrum is
obtained in closed form, and is dominated by long tails that in contrast to
previous work are found to exhibit a slow logarithmic decay rather than
power-law form, crossing over to characteristic Fermi liquid behaviour on the
lowest energy scales. The resultant theory, while naturally approximate, is
found to give very good agreement for essentially all frequencies with
numerical renormalization group calculations of both the single-particle
scaling spectrum and the self-energy.Comment: 16 pages, 4 embedded figure
Predictive validity of the short-term assessment of risk and treatability (START) for aggression and self-harm in a secure mental health service:gender differences
The START predicts aggressive outcomes and to some extent self-harm. However, it is not known whether gender moderates its performance. This study used routinely collected data to investigate the predictive ability of the START for aggression and self-harm in secure psychiatric patients. Utility of the START was examined separately for men and women. The START was a stronger predictor of aggression and self-harm in women than men. The specific risk estimates produced large effect sizes for the prediction of aggression and self-harm in women; none of the AUC values reached the threshold for a large effect size in the male sample
Predictive validity of the START for unauthorised leave and substance abuse in a secure mental health setting:a pseudo-prospective cohort study
Background Risk assessment and management is central to the nursing role in forensic mental health settings. The Short Term Assessment of Risk and Treatability (START) aims to support assessment through identification of risk and protective factors. It has demonstrated predictive validity for aggression; it also aims to aid risk assessment for unauthorised leave and substance abuse where its performance is relatively untested. Objectives To test the predictive validity of the START for unauthorised leave and substance abuse. Design A naturalistic, pseudo-prospective cohort study. Settings Four centres of a large UK provider of secure inpatient mental health services. Participants Inpatients resident between May 2011 and October 2013 who remained in the service for 3-months following assessment with the START by their clinical team. Exclusion criteria were missing assessment data in excess of prorating guidelines. Of 900 eligible patients 73 were excluded leaving a final sample size of n = 827 (response rate 91.9%). Mean age was 38.5 years (SD = 16.7); most participants (72.2%) were male; common diagnoses were schizophrenia-type disorders, personality disorders, organic disorders, developmental disorders and intellectual disability. Methods Routinely conducted START assessments were gathered. Subsequent incidents of substance abuse and unauthorised leave were coded independently. Positive and negative predictive values of low and elevated risk were calculated. Receiver Operating Characteristic analysis was conducted to ascertain the predictive accuracy of the assessments based on their sensitivity and specificity. Results Patient-based rates of unauthorised leave (2.4%) and substance abuse (1.6%) were low. The positive and negative predictive values for unauthorised leave were 5.9% and 98.4%; and for substance abuse 8.1% and 99.0%. The START specific risk estimate for unauthorised leave predicted its associated outcome (Area under the curve = .659, p < .05, 95% CI .531, .786); the substance abuse risk estimate predicted its outcome with a large effect size (Area under the curve = .723, p < .01, 95% CI .568, .879). Conclusions The study provides limited support for the START by demonstrating the predictive validity of its specific risk estimates for substance abuse and unauthorised leave. High negative predictive values suggest the tool may be of most utility in screening out low risk individuals from unnecessary restrictive interventions; very low positive predictive values suggest caution before implementing restrictive interventions in those rated at elevated risk. Researchers should investigate how multidisciplinary teams formulate risk assessments for these outcomes since they outperform the quantitative element of this tool
Role of assessment components and recent adverse outcomes in risk estimation and prediction:use of the Short Term Assessment of Risk and Treatability (START) in an adult secure inpatient mental health service
The Short Term Assessment of Risk and Treatability is a structured judgement tool used to inform risk estimation for multiple adverse outcomes. In research, risk estimates outperform the tool's strength and vulnerability scales for violence prediction. Little is known about what its’component parts contribute to the assignment of risk estimates and how those estimates fare in prediction of non-violent adverse outcomes compared with the structured components. START assessment and outcomes data from a secure mental health service (N=84) was collected. Binomial and multinomial regression analyses determined the contribution of selected elements of the START structured domain and recent adverse risk events to risk estimates and outcomes prediction for violence, self-harm/suicidality, victimisation, and self-neglect. START vulnerabilities and lifetime history of violence, predicted the violence risk estimate; self-harm and victimisation estimates were predicted only by corresponding recent adverse events. Recent adverse events uniquely predicted all corresponding outcomes, with the exception of self-neglect which was predicted by the strength scale. Only for victimisation did the risk estimate outperform prediction based on the START components and recent adverse events. In the absence of recent corresponding risk behaviour, restrictions imposed on the basis of START-informed risk estimates could be unwarranted and may be unethical
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