1,082 research outputs found
The sensitivity of secondary organic aerosol component partitioning to the predictions of component properties – Part 1: A systematic evaluation of some available estimation techniques
A large number of calculations of the absorptive partitioning of organic compounds have been made using a number of methods to predict the component vapour pressures, <i>p</i><sup>0</sup>, and activity coefficients, <i>γ</i><sub><i>i</i></sub>, required in the calculations. The sensitivities of the predictions in terms of the condensed component masses, volatility, O:C ratio, molar mass and functionality distributions to the choice of <i>p</i><sup>0</sup> and <i>γ</i><sub><i>i</i></sub> models and to the number of components to represent the organic mixture have been systematically compared. The condensed component mass was found to be highly sensitive to the vapour pressure model, and less sensitive to both the activity coefficient model and the number of components used to represent the mixture although the sensitivity to the change in property estimation method increased substantially with increased simplification in the treatment of the organic mixture. This was a general finding and was also clearly evident in terms of the predicted component functionality, O:C ratio, molar mass and volatility distributions of the condensed organic components. Within the limitations of the study, this clearly demonstrates the requirement for more accurate representation of the <i>p</i><sup>0</sup> and <i>γ</i><sub><i>i</i></sub> of the semi-volatile organic proxy components used in simplified models as the degree of simplification increases. This presents an interesting paradox, since such reduction in complexity necessarily leads to divergence from the complex behaviour of real multicomponent atmospheric aerosol
Solid state and sub-cooled liquid vapour pressures of substituted dicarboxylic acids using Knudsen Effusion Mass Spectrometry (KEMS) and Differential Scanning Calorimetry
Solid state vapour pressures of a selection of atmospherically important substituted dicarboxylic acids have been measured using Knudsen Effusion Mass Spectrometry (KEMS) over a range of 20 K (298–318 K). Enthalpies of fusion and melting points obtained using Differential Scanning Calorimetry (DSC) were used to obtain sub-cooled liquid vapour pressures. They have been compared to estimation methods used on the E-AIM website. These methods are shown to poorly represent – OH groups in combination with COOH groups. Partitioning calculations have been performed to illustrate the impact of the different estimation methods on organic aerosol mass compared to the use of experimental data
The UPBEAT nurse-delivered personalized care intervention for people with coronary heart disease who report current chest pain and depression: a randomised controlled pilot study
Background: Depression is common in people with coronary heart disease (CHD) and associated with worse outcome. This study explored the acceptability and feasibility of procedures for a trial and for an intervention, including its potential costs, to inform a definitive randomized controlled trial (RCT) of a nurse-led personalised care intervention for primary care CHD patients with current chest pain and probable depression.
Methods: Multi-centre, outcome assessor-blinded, randomized parallel group study. CHD patients reporting chest pain and scoring 8 or more on the HADS were randomized to personalized care (PC) or treatment as usual (TAU) for 6 months and followed for 1 year. Primary outcome was acceptability and feasibility of procedures; secondary outcomes included mood, chest pain, functional status, well being and psychological process variables.
Result: 1001 people from 17 General Practice CHD registers in South London consented to be contacted; out of 126 who were potentially eligible, 81 (35% female, mean age = 65 SD11 years) were randomized. PC participants (n = 41) identified wide ranging problems to work on with nurse-case managers. Good acceptability and feasibility was indicated by low attrition (9%), high engagement and minimal nurse time used (mean/SD = 78/19 mins assessment, 125/91 mins telephone follow up). Both groups improved on all outcomes. The largest between group difference was in the proportion no longer reporting chest pain (PC 37% vs TAU 18%; mixed effects model OR 2.21 95% CI 0.69, 7.03). Some evidence was seen that self efficacy (mean scale increase of 2.5 vs 0.9) and illness perceptions (mean scale increase of 7.8 vs 2.5) had improved in PC vs TAU participants at 1 year. PC appeared to be more cost effective up to a QALY threshold of approximately £3,000.
Conclusions: Trial and intervention procedures appeared to be feasible and acceptable. PC allowed patients to work on unaddressed problems and appears cheaper than TAU
The effect of photochemical ageing and initial precursor concentration on the composition and hygroscopic properties of β-caryophyllene secondary organic aerosol
The effect of photochemical ageing and initial precursor concentration on
the composition and hygroscopic properties of secondary organic aerosol
(SOA) formed during the chamber photo-oxidation of β-caryophyllene/NO<sub>x</sub>
mixtures were investigated. Nucleation of β-caryophyllene SOA particles occurred almost immediately after oxidation
was initiated and led to the formation of fresh SOA with a relatively
simpler composition than has been reported for monoterpenes. The SOA yield
values ranged from 9.5–26.7% and 30.4–44.5% using a
differential mobility particle sizer (DMPS) and an aerosol mass spectrometer
(AMS) mass based measurements, respectively. A total of 20 compounds were
identified in the SOA by LC-MS/MS, with the most abundant compounds
identified as β-caryophyllonic acid and β-caryophyllinic
acid/β-nocaryophyllonic acid. The O:C and H:C elemental ratios of
products identified in the condensed phase ranged from 0.20 to 1.00 and 1.00
to 2.00, with average values of 0.39 and 1.58, respectively. The increase in
the O:C ratio was associated with a decrease in the saturation concentration
of the identified compounds. The compounds identified in the lower initial
concentration experiments were more oxidised compared to those that were
found to be more abundant in the higher initial concentration experiments
with average O:C ratios of 0.51 and 0.27, respectively. Photochemical ageing
led to a more complex SOA composition with a larger contribution coming from
lower molar mass, higher generation products, where both double bonds had
been oxidised. This effect was more evident in the experiments conducted
using the lower initial precursor concentration; a finding confirmed by the
temporal behaviour of key organic mass fragment measured by an Aerosol Mass
Spectrometer. Although the composition changed with both initial precursor
concentration and ageing, this had no significant measurable effect on the
hygroscopic properties of the SOA formed. The latter finding might have been
influenced by the difference in pre-treatment of the semivolatile-containing
particles prior to their measurements
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Embedded Agency in Institutional Theory: Problem or Paradox
In “Beyond Constraining and Enabling: Toward New Microfoundations in Institutional Theory” Professor Cardinale (2018) seeks to expose and correct “shortcomings” (p.133) in institutional theory’s conceptualization of structure, agency and their relationship. To this end, he theorizes the “different mechanism[s] through which actors are embedded in structure” (p.134). We agree that institutional theory’s microfoundations merit theoretical attention and development. However, we question the premise that the issue of agency in institutional theory is adequately, or even plausibly, formulated as one of “embeddedness”. We also challenge the relevance of Professor Cardinale’s engagement of Husserl to help solve what we argue to be a phantom problem central to his theory
Understanding Video Game Developers as an Occupational Community
The video game industry has rapidly expanded over the last four decades; yet there is limited research about the workers who make video games. In examining these workers, this article responds to calls for renewed attention to the role of the occupation in understanding project-based workers in boundaryless careers. Specifically, this article uses secondary analysis of online sources to demonstrate that video game developers can be understood as a unique social group called an occupational community (OC). Once this classification has been made, the concept of OC can be used in future research to understand video game workers in terms of identity formation, competency development, career advancement and support, collective action, as well as adherence to and deviance from organizational and industry norms
Negotiating networks of self-employed work: strategies of minority ethnic contractors
Within the increased flexible, contracted work in cities, employment is negotiated through network arrangements characterised by multiplicity, mobility and fluidity. For black and minority ethnic group members, this network labour becomes fraught as they negotiate both their own communities, which can be complex systems of conflicting networks, as well as non-BME networks which can be exclusionary. This discussion explores the networking experiences of BME individuals who are self-employed in portfolio work arrangements in Canada. The analysis draws from a theoretical frame of ‘racialisation’ (Mirchandani and Chan, 2007) to examine the social processes of continually constructing and positioning the Other as well as the self through representations in these networks. These positions and concomitant identities enroll BME workers in particular modes of social production, which order their roles and movement in the changing dynamics of material production in networked employment
Development and evaluation of a de-escalation training intervention in adult acute and forensic units: the EDITION systematic review and feasibility trial.
Containment (e.g. physical restraint and seclusion) is used frequently in mental health inpatient settings. Containment is associated with serious psychological and physical harms. De-escalation (psychosocial techniques to manage distress without containment) is recommended to manage aggression and other unsafe behaviours, for example self-harm. All National Health Service staff are trained in de-escalation but there is little to no evidence supporting training's effectiveness. Objectives were to: (1) qualitatively investigate de-escalation and identify barriers and facilitators to use across the range of adult acute and forensic mental health inpatient settings; (2) co-produce with relevant stakeholders an intervention to enhance de-escalation across these settings; (3) evaluate the intervention's preliminary effect on rates of conflict (e.g. violence, self-harm) and containment (e.g. seclusion and physical restraint) and understand barriers and facilitators to intervention effects. Intervention development informed by Experience-based Co-design and uncontrolled pre and post feasibility evaluation. Systematic reviews and qualitative interviews investigated contextual variation in use and effects of de-escalation. Synthesis of this evidence informed co-design of an intervention to enhance de-escalation. An uncontrolled feasibility trial of the intervention followed. Clinical outcome data were collected over 24 weeks including an 8-week pre-intervention phase, an 8-week embedding and an 8-week post-intervention phase. Ten inpatient wards (including acute, psychiatric intensive care, low, medium and high secure forensic) in two United Kingdom mental health trusts. In-patients, clinical staff, managers, carers/relatives and training staff in the target settings. Enhancing de-escalation techniques in adult acute and forensic units: Development and evaluation of an evidence-based training intervention (EDITION) interventions included de-escalation training, two novel models of reflective practice, post-incident debriefing and feedback on clinical practice, collaborative prescribing and ward rounds, practice changes around admission, shift handovers and the social and physical environment, and sensory modulation and support planning to reduce patient distress. Outcomes measured related to feasibility (recruitment and retention, completion of outcome measures), training outcomes and clinical and safety outcomes. Conflict and containment rates were measured via the Patient-Staff Conflict Checklist. Clinical outcomes were measured using the Attitudes to Containment Measures Questionnaire, Attitudes to Personality Disorder Questionnaire, Violence Prevention Climate Scale, Capabilities, Opportunities, and Motivation Scale, Coercion Experience Scale and Perceived Expressed Emotion in Staff Scale. Completion rates of the proposed primary outcome were very good at 68% overall (excluding remote data collection), which increased to 76% (excluding remote data collection) in the post-intervention period. Secondary outcomes had high completion rates for both staff and patient respondents. Regression analyses indicated that reductions in conflict and containment were both predicted by study phase (pre, embedding, post intervention). There were no adverse events or serious adverse events related to the intervention. Intervention and data-collection procedures were feasible, and there was a signal of an effect on the proposed primary outcome. Uncontrolled design and self-selecting sample. Definitive trial determining intervention effects. This trial is registered as ISRCTN12826685 (closed to recruitment). This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 16/101/02) and is published in full in ; Vol. 28, No. 3. See the NIHR Funding and Awards website for further award information. Conflict (a term used to describe a range of potentially unsafe events including violence, self-harm, rule-breaking, medication refusal, illicit drug and alcohol use and absconding) in mental health settings causes serious physical and psychological harm. Containment interventions which are intended to minimise harm from violence (and other conflict behaviours) such as restraint, seclusion and rapid tranquilisation can result in serious injuries to patients and, occasionally, death. Involvement in physical restraint is the most common cause of serious physical injury to National Health Service mental health staff in the United Kingdom. Violence to staff results in substantial costs to the health service in sickness and litigation payments. Containment interventions are also expensive (e.g. physical restraint costs mental health services £6.1 million and enhanced observations £88 million per annum). Despite these harms, recent findings indicate containment interventions such as seclusion and physical restraint continue to be used frequently in mental health settings. Clinical trials have demonstrated that interventions can reduce containment without increasing violence and other conflict behaviours (e.g. verbal aggression, self-harm). Substantial cost-savings result from reducing containment use. De-escalation, as an intervention to manage aggression and potential violence without restrictive practices, is a core intervention. 'De-escalation' is a collective term for a range of psychosocial techniques designed to reduce distress and anger without the need to use 'containment' interventions (measures to prevent harm through restricting a person's ability to act independently, such as physical restraint and seclusion). Evidence indicates that de-escalation involves ensuring conditions for safe intervention and effective communication are established, clarifying and attempting to resolve the patient's concern, conveyance of respect and empathy and regulating unhelpful emotions such as anxiety and anger. Despite featuring prominently in clinical guidelines and training policy domestically and internationally and being a component of mandatory National Health Service training, there is no evidence-based model on which to base training. A systematic review of de-escalation training effectiveness and acceptability conducted in 2015 concluded: (1) no model of training has demonstrated effectiveness in a sufficiently rigorous evaluation, (2) the theoretical underpinning of evaluated models was often unclear and (3) there has been inadequate investigation of the characteristics of training likely to enhance acceptability and uptake. Despite all National Health Service staff being trained in de-escalation there have been no high-quality trials evaluating the effectiveness and cost-effectiveness of training. Feasibility studies are needed to establish whether it is possible to conduct a definitive trial that can determine the clinical, safety and cost-effectiveness of this intervention
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Performative Work: Bridging Performativity and Institutional Theory in the Responsible Investment Field
Callon’s performativity thesis has illuminated how economic theories and calculative devices shape markets, but has been challenged for its neglect of the organizational, institutional and political context. Our seven-year qualitative study of a large financial data company found that the company’s initial attempt to change the responsible investment field through a performative approach failed because of the constraints posed by field practices and organizational norms on the design of the calculative device. However, the company was subsequently able to put in place another form of performativity by attending to the normative and regulative associations of the device. We theorize this route to performativity by proposing the concept of performative work, which designates the necessary institutional work to enable translation and the subsequent adoption of the device. We conclude by considering the implications of performative work for the performativity and the institutional work literatures
Chemotherapy in advanced ovarian cancer: four systematic meta-analyses of individual patient data from 37 randomized trials. Advanced Ovarian Cancer Trialists' Group.
The purpose of this systematic study was to provide an up to date and reliable quantitative summary of the relative benefits of various types of chemotherapy (non-platinum vs platinum, single-agent vs combination and carboplatin vs cisplatin) in the treatment of advanced ovarian cancer. Also, to investigate whether well-defined patient subgroups benefit more or less from cisplatin- or carboplatin-based therapy. Meta-analyses were based on updated individual patient data from all available randomized controlled trials (published and unpublished), including 37 trials, 5667 patients and 4664 deaths. The results suggest that platinum-based chemotherapy is better than non-platinum therapy, show a trend in favour of platinum combinations over single-agent platinum, and suggest that cisplatin and carboplatin are equally effective. There is no good evidence that cisplatin is more or less effective than carboplatin in any particular subgroup of patients
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