Degree of explanation

Partial explanations are everywhere. That is, explanations citing causes that explain some but not all of an effect are ubiquitous across science, and these in turn rely on the notion of degree of explanation. I argue that current accounts are seriously deficient. In particular, they do not incorporate adequately the way in which a cause’s explanatory importance varies with choice of explanandum. Using influential recent contrastive theories, I develop quantitative definitions that remedy this lacuna, and relate it to existing measures of degree of causation. Among other things, this reveals the precise role here of chance, as well as bearing on the relation between causal explanation and causation itself

The use of Performance Measurement as an Accountability Mechanism: a case study in the UK National Health Service

The UK Labour government has recently developed the NHS Plan, which specifies long-term objectives and strategies for the development of the National Health Service. Along with the NHS Plan has come the development of Service and Financial Frameworks (SaFFs). The aim of SaFFs is to overcome the potential agency problem that exists between government and NHS organizations (Heymann, 1988) by enhancing the accountability of local NHS organizations for delivering the outcomes required by the NHS Plan. This study uses a case study to explore how the SaFF has been applied as a new NHS performance measurement tool and identifies issues affecting the usefulness of the SaFF as an accountability mechanism. The findings illustrate how the introduction of SaFFs has allowed the government to introduce additional non-financial/process performance indicators and tougher performance monitoring processes. This study also identifies issues related to the choice, relevance and informational quality of performance indicators. The findings suggest that, given the shortcomings in the SaFF’s performance measurement contributions, a key early aim of this new accountability mechanism may be to serve central government’s need to deliver a political message to the public. If the SaFF is to develop into an effective accountability mechanism and support the key aims of the NHS Plan, careful selection of performance indicators and adequate information systems will be crucial

Torsion in Milnor fiber homology

In a recent paper, Dimca and Nemethi pose the problem of finding a homogeneous polynomial f such that the homology of the complement of the hypersurface defined by f is torsion-free, but the homology of the Milnor fiber of f has torsion. We prove that this is indeed possible, and show by construction that, for each prime p, there is a polynomial with p-torsion in the homology of the Milnor fiber. The techniques make use of properties of characteristic varieties of hyperplane arrangements.Comment: Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol3/agt-3-16.abs.htm

“Struggling to stay connected”: comparing the social relationships of healthy older people and people with stroke and aphasia

Background: Having a stroke and aphasia can profoundly affect a person’s social relationships. Further, poor social support is associated with adverse post-stroke outcomes such as psychological distress, worse quality of life, and worse recovery. To date, no study has used complex measures of social network and perceived social support to compare stroke survivors with aphasia, without aphasia, and the general older population. A better understanding of which aspects of social support are most affected by stroke and aphasia may inform stroke services. Aims: To compare the social networks and perceived functional social support of people following a stroke, with and without aphasia, and healthy older adults. Methods & Procedures: Cross-sectional interview-based study. People with a first stroke were recruited from two acute stroke units and interviewed 6 months post onset. We recruited 60 stroke participants without aphasia, average age 69.8 (SD = 14.3), and 11 stroke participants with aphasia, average age 66.5 (SD = 13.7). One hundred and six healthy older adults were recruited via the community, average age 62.8 (SD = 9.5). All participants completed the Medical Outcomes Study Social Support Survey (SSS) and the Stroke Social Network Scale (SSNS). One-way independent groups ANOVAs were used to compare stroke participants with aphasia, stroke participants without aphasia, and healthy older adults. Outcomes & Results: After adjusting for multiple comparisons (p < .004), there was a significant difference on overall social network between the three groups (p < .001), with those with aphasia scoring significantly lower than healthy older adults (p < .001). The difference between healthy older adults and people with aphasia on the friends domain of the social network scale was also significant (p = .002). There was no significant difference between the three groups on overall perceived functional social support. Conclusions: People with aphasia have less diverse social networks than healthy older adults, with friendships particularly affected. Stroke services should monitor for social isolation, and consider ways to support people following a stroke in maintaining or establishing diverse social networks

It's just a feeling: why economic models do not explain

Julian Reiss correctly identified a trilemma about economic models: we cannot maintain that they are false, but nevertheless explain and that only true accounts explain. In this reply we give reasons to reject the second premise – that economic models explain. Intuitions to the contrary should be distrusted

Adjustment with aphasia after stroke: study protocol for a pilot feasibility randomised controlled trial for SUpporting wellbeing through PEeR Befriending (SUPERB)

Background: Despite the high prevalence of mood problems after stroke, evidence on effective interventions particularly for those with aphasia is limited. There is a pressing need to systematically evaluate interventions aiming to improve wellbeing for people with stroke and aphasia. This study aims to evaluate the feasibility of a peer-befriending intervention. Methods/design: SUPERB is a single blind, parallel group feasibility trial of peer befriending for people with aphasia post-stroke and low levels of psychological distress. The trial includes a nested qualitative study and pilot economic evaluation and it compares usual care (n = 30) with usual care + peer befriending (n = 30). Feasibility outcomes include proportion screened who meet criteria, proportion who consent, rate of consent, number of missing/incomplete data on outcome measures, attrition rate at follow-up, potential value of conducting main trial using value of information analysis (economic evaluation), description of usual care, and treatment fidelity of peer befriending. Assessments and outcome measures (mood, wellbeing, communication, and social participation) for participants and significant others will be administered at baseline, with outcome measures re-administered at 4 and 10 months post-randomisation. Peer befrienders will complete outcome measures before training and after they have completed two cycles of befriending. The qualitative study will use semi-structured interviews of purposively sampled participants (n = 20) and significant others (n = 10) from both arms of the trial, and all peer befrienders to explore the acceptability of procedures and experiences of care. The pilot economic evaluation will utilise the European Quality of life measure (EQ-5D-5 L) and a stroke-adapted version of the Client Service Receipt Inventory (CSRI). Discussion: This study will provide information on feasibility outcomes and an initial indication of whether peer befriending is a suitable intervention to explore further in a definitive phase III randomised controlled trial. Trial registration: ClinicalTrials.gov identifier NCT02947776, registered 28th October 2016

The visual orbits of the spectroscopic binaries HD 6118 and HD 27483 from the Palomar Testbed Interferometer

We present optical interferometric observations of two double-lined spectroscopic binaries, HD 6118 and HD 27483, taken with the Palomar Testbed Interferometer (PTI) in the K band. HD 6118 is one of the most eccentric spectroscopic binaries and HD 27483 a spectroscopic binary in the Hyades open cluster. The data collected with PTI in 2001-2002 allow us to determine astrometric orbits and when combined with the radial velocity measurements derive all physical parameters of the systems. The masses of the components are 2.65 +/- 0.27 M_Sun and 2.36 +/- 0.24 M_Sun for HD 6118 and 1.38 +/- 0.13 M_Sun and 1.39 +/- 0.13 M_Sun for HD 27483. The apparent semi-major axis of HD 27483 is only 1.2 mas making it the closest binary successfully observed with an optical interferometer.Comment: submitted to Ap

Psychometric properties of the Stroke and Aphasia Quality of Life Scale (SAQOL-39) in a generic stroke population

Background: We previously developed the Stroke and Aphasia Quality of Life scale (SAQOL-39) and tested it with people with chronic aphasia. A scale allowing comparisons of quality of life between people with versus without aphasia post-stroke would be of value to clinicians. Objectives: To evaluate the psychometrics of the SAQOL-39 in a generic stroke sample. Should this process result in a generic-stroke version of the scale (SAQOL-39g), a further aim is to compare the latter and the SAQOL-39 as tested in chronic aphasia. Design and subjects: Repeated measures psychometric study, evaluating internal consistency, test—retest reliability, construct validity and responsiveness to change. People admitted to hospital with a first stroke were assessed two weeks, three months and six months post stroke. Measures: SAQOL-39, National Institutes of Health Stroke Scale, Barthel, Frenchay Aphasia Screening Test, General Health Questionnaire-12 and Frenchay Activities Index. Results: Of 126 eligible participants, 96 (76%) participated and 87 (69%) were able to self-report and are presented here. Testing the SAQOL-39 in generic stroke resulted in the SAQOL-39g, which has the same items as the SAQOL-39 but three domains: physical, psychosocial, communication. The SAQOL-39g showed good internal consistency (α = 0.95 overall score, 0.92—0.95 domains), test—retest reliability (interclass correlation (ICC) = 0.96 overall, 0.92—0.98 domains), convergent (r = 0.36—0.70 overall, 0.47—0.78 domains) and discriminant validity (r = 0.26 overall, 0.03—0.40 domains). It differentiated people by stroke severity and visual analogue scale (VAS)-defined quality of life. Moderate changes (d = 0.35—0.49; standardized response mean (SRM) = 0.29—0.53) from two weeks to six months supported responsiveness. Conclusions: The SAQOL-39g demonstrated good reliability, validity and responsiveness to change. It can be used to evaluate quality of life in people with and without aphasia post stroke

SOlution Focused brief therapy In post-stroke Aphasia (SOFIA Trial): protocol for a feasibility randomised controlled trial

Background: Around a quarter of people post stroke will experience aphasia, a language disability. Having aphasia places someone at risk of becoming depressed and isolated. There is limited evidence for effective interventions to enhance psychological well-being for this client group. A potential intervention is Solution Focused Brief Therapy (SFBT), which supports a person to build meaningful, achievable change through focusing on a person’s skills and resources rather than their deficits. The SOFIA Trial aims to explore the acceptability of SFBT to people with varying presentations of aphasia, including severe aphasia, and to assess the feasibility of conducting a future definitive trial investigating clinical and cost effectiveness. Methods: The trial is a single-blind, randomised, wait-list controlled feasibility trial with nested qualitative research and pilot economic evaluation comparing SFBT plus usual care to usual care alone. The study will recruit 32 participants with aphasia who are ≥6 months post stroke. All participants will be assessed on psychosocial outcome measures at baseline, then at three and six months post randomisation by assessors blinded to treatment allocation. Participants will be randomly assigned to intervention group (start intervention immediately post randomisation) or wait-list group (start intervention six months post randomisation). Wait-list group will additionally be assessed nine months post randomisation. The intervention consists of up to six SFBT sessions delivered over three months by speech and language therapists. Participants and therapists will also take part in in-depth interviews exploring their experiences of the study. The pilot economic evaluation will use the EQ-5D-5L measure and an adapted Client Service Receipt Inventory. People with aphasia have been involved in designing and monitoring the trial. Discussion: Given the high levels of depression and isolation, there is a need to investigate effective interventions that enhance the psychological wellbeing of people with aphasia. Trial registration: ClinicalTrials.gov NCT03245060. 10/08/2017

Stressful Working Conditions and Union Dissatisfaction

Les conditions de travail stressantes et l'angoisse qui en résulte pour les employés reçoivent de plus en plus d'attention. De telles conditions de travail mènent à des symptômes physiologiques et psychologiques d'angoisse, d'insatisfaction envers le travail, d'aliénation, de basse productivité et de roulement. Dans un tel contexte, les employés syndiqués peuvent se tourner vers leur syndicat dans l'espoir que celui-ci obtienne de meilleures conditions de travail. De plus, on peut supposer que les travailleurs qui perçoivent leur syndicat comme un allié ont envers lui une orientation positive. En d'autres termes, l'hypothèse est à l'effet que plus les conditions de travail sont stressantes, et plus l'angoisse est grande chez les travailleurs, plus leur orientation envers le syndicat sera positive. Cependant, il est également possible que des employés aux conditions de travail stressantes, angoissés et aliénés deviendront insatisfaits non seulement de leur travail mais également de leur syndicat qu'ils peuvent blâmer de n'avoir pu obtenir de meilleures conditions de travail. Peu d'études, à ce jour, ont examiné les relations entre le travail stressant et le degré de satisfaction envers son syndicat. De plus, le peu de littérature qui existe à ce sujet est équivoque. Quelques études concluent que le travail stressant est associé avec la satisfaction envers le syndicat alors d'autres concluent le contraire, ou encore à l'absence de relations entre ces deux variables. Nous cherchons ici à examiner la relation entre les conditions de travail stressantes, l'angoisse des employés et l'orientation des travailleurs envers leur syndicat.Les données pour la présente étude viennent d'une enquête effectuée en 1983 auprès des postiers syndiqués (n=992) travaillant pour Poste Canada à Edmonton. Les conditions de travail sont évaluées par membership syndical (postiers et facteurs), quart de travail, rapports des travailleurs eu égard aux problèmes avec les heures travaillées, nombre de risques eu égard à la santé et la sécurité au travail et les caractéristiques du travail incluant la supervision, l'intensité de travail, l'autonomie décisionnelle, les récompenses financières, les relations entre les travailleurs, les conflits de travail et le degré de routine. Nous avons mesuré le support social au travail en demandant aux employés jusqu'à quel point il pouvait compter sur leur supérieur, le délégué ou représentant syndical et sur d'autres personnes au travail. Nous avons également interrogé les répondants sur leur implication dans leur syndicat et sur leurs perceptions des relations du travail. Finalement, quant au stress vécu par ces travailleurs, nous avons utilisé de multiple mesures de satisfaction au travail, de bien-être psychologique/ angoisse, de bien-être physique/angoisse, et l'impact perçu du travail sur la santé.La variable dépendante pour cette étude est la (in)satisfaction envers le syndicat. Cette variable combine une échelle de rangement de sept échelons du syndicat avec les réponses des employés à une question ouverte « comment votre syndicat pourrait mieux vous servir ? ». Nous avons créé trois catégories: fortes critiques du syndicat (n=192), critiques modérées (n=360) et aucune critique (n=440). Aux fins de l'analyse de régression, les critiques fortes et modérées ont été fusionnées. Les analyses bi-variées montrent que les membres du syndicat des postiers, les travailleurs des quarts d'après-midi ou de nuit, ceux rapportant des problèmes avec les heures de travail et les répondants qui disent être exposés à de hauts niveaux de risques au travail sont plus enclins à être fortement critiques de leur syndicat. De plus, les employés rapportant une supervision pauvre, un défi et une variété limités dans leurs tâches et des collègues et représentants syndicaux qui ne les supportent pas critiquent plus leur syndicat, comme cela est d'ailleurs le cas de ceux qui perçoivent les relations du travail comme hostiles. Finalement, ceux qui rapportent les pires santés physiques et mentales, de plus grands conflits travail-famille, et de l'insatisfaction envers leur travail, sont aussi de forts critiques de leur syndicat. En résumé, il semble que les différentes mesures de conditions de travail stressantes et l'angoisse des employés soient reliées avec une position critique envers le syndicat. Une analyse de régression multivariée confirme qu'un modèle qui inclut ces variables prédit, à un degré statistiquement significatif, l'orientation des employés envers leur syndicat. Plus particulièrement, l'analyse multivariée démontre que les employés qui considèrent leur travail stressant, leur représentant syndical inutile, et leur syndicat inefficace à améliorer les conditions de travail, tendent à être de forts critiques de leur syndicat.En conclusion, cette étude établit que des conditions de travail stressantes et le stress au travail en résultant associés avec un manque de support au travail (supérieur, collègue, syndicat) mènent à une orientation négative envers le syndicat. Alors, des conditions de travail stressantes peuvent non seulement aliéner les travailleurs eu égard à leur travail et compromettre leur santé, mais également les aliéner eu égard à leur syndicat.This paper examines the relationship between stressful working conditions, social support at work, employee distress, and union members' (dis)satisfaction with their union. It might be assumed that under stressful working conditions, unionized workers would turn to their union to seek better working conditions and would have a positive orientation toward their union. However, it is also possible that stressful working conditions and distressed, alienated employees will become dissatisfied not only with their job but also with their union. The data for this study corne from a survey of unionized postal workers employed by Canada Post Corporation in Edmonton in 1983