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 Peak Brightness and Spatial Distribution of AGB Stars Near the Nucleus of M32

The bright stellar content near the center of the Local Group elliptical galaxy M32 is investigated with 0.12 arcsec FWHM H and K images obtained with the Gemini Mauna Kea telescope. Stars with K = 15.5, which are likely evolving near the tip of the asymptotic giant branch (AGB), are resolved to within 2 arcsec of the nucleus, and it is concluded that the peak stellar brightness near the center of M32 is similar to that in the outer regions of the galaxy. Moreover, the projected density of bright AGB stars follows the visible light profile to within 2 arcsec of the nucleus, indicating that the brightest stars are well mixed throughout the galaxy. Thus, there is no evidence for an age gradient, and the radial variations in spectroscopic indices and ultraviolet colors that have been detected previously must be due to metallicity and/or some other parameter. We suggest that either the bright AGB stars formed as part of a highly uniform and coherent galaxy-wide episode of star formation, or they originated in a separate system that merged with M32.Comment: 9 pages of text, 3 figures. ApJ (Letters) in pres

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

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

Does mode of administration affect health-related quality-of-life outcomes after stroke?

Telephone interviews and postal surveys may be a resource-efficient way of assessing health-related quality-of-life post-stroke, if they produce data equivalent to face-to-face interviews. This study explored whether telephone interviews and postal surveys of the Stroke and Aphasia Quality of Life Scale (SAQOL-39g) yielded similar results to face-to-face interviews. Participants included people with aphasia and comprised two groups: group one (n =22) were 3-6 months post-stroke; group two (n =26) were ≥1 year post-stroke. They completed either a face-to-face and a telephone interview or a face-to-face interview and a postal survey of the SAQOL-39g. Response rates were higher for group two (87%) than for group one (72-77%). There were no significant differences between respondents and non-respondents on demographics, co-morbidities, stroke severity, or communication impairment. Concordance between face-to-face and telephone administrations (.90-.98) was excellent; and very good-excellent between face-to-face and postal administrations (.84-.96), although scores in postal administrations were lower (significant for psychosocial domain and overall SAQOL-39g in group two). These findings suggest that the SAQOL-39g yields similar results in different modes of administration. Researchers and clinicians may employ alternative modes, particularly in the longer term post-stroke, in order to reduce costs or facilitate clients with access difficulties

'A habitual disposition to the good': on reason, virtue and realism

Amidst the crisis of instrumental reason, a number of contemporary political philosophers including Jürgen Habermas have sought to rescue the project of a reasonable humanism from the twin threats of religious fundamentalism and secular naturalism. In his recent work, Habermas defends a post-metaphysical politics that aims to protect rationality against encroachment while also accommodating religious faith within the public sphere. This paper contends that Habermas’ post-metaphysical project fails to provide a robust alternative either to the double challenge of secular naturalism and religious fundamentalism or to the ruthless instrumentalism that underpins capitalism. By contrast with Habermas and also with the ‘new realism’ of contemporary political philosophers such as Raymond Geuss or Bernard Williams, realism in the tradition of Plato and Aristotle can defend reason against instrumental rationality and blind belief by integrating it with habit, feeling and even faith. Such metaphysical–political realism can help develop a politics of virtue that goes beyond communitarian thinking by emphasising plural modes of association (not merely ‘community’), substantive ties of sympathy and the importance of pursuing goodness and mutual flourishing

Rapid, reliable, and reproducible molecular sub-grouping of clinical medulloblastoma samples

The diagnosis of medulloblastoma likely encompasses several distinct entities, with recent evidence for the existence of at least four unique molecular subgroups that exhibit distinct genetic, transcriptional, demographic, and clinical features. Assignment of molecular subgroup through routine profiling of high-quality RNA on expression microarrays is likely impractical in the clinical setting. The planning and execution of medulloblastoma clinical trials that stratify by subgroup, or which are targeted to a specific subgroup requires technologies that can be economically, rapidly, reliably, and reproducibly applied to formalin-fixed paraffin embedded (FFPE) specimens. In the current study, we have developed an assay that accurately measures the expression level of 22 medulloblastoma subgroup-specific signature genes (CodeSet) using nanoString nCounter Technology. Comparison of the nanoString assay with Affymetrix expression array data on a training series of 101 medulloblastomas of known subgroup demonstrated a high concordance (Pearson correlation r = 0.86). The assay was validated on a second set of 130 non-overlapping medulloblastomas of known subgroup, correctly assigning 98% (127/130) of tumors to the appropriate subgroup. Reproducibility was demonstrated by repeating the assay in three independent laboratories in Canada, the United States, and Switzerland. Finally, the nanoString assay could confidently predict subgroup in 88% of recent FFPE cases, of which 100% had accurate subgroup assignment. We present an assay based on nanoString technology that is capable of rapidly, reliably, and reproducibly assigning clinical FFPE medulloblastoma samples to their molecular subgroup, and which is highly suited for future medulloblastoma clinical trials

Aphasia blog talk: How does stroke and aphasia affect a person’s social relationships?

Background: Stroke and aphasia can negatively affect a person’s ability to maintain healthy social relationships, both within the family and also with friends and the wider network. To date, this has been explored predominantly through qualitative interviews and questionnaires. Blogs written by people with aphasia constitute a novel source of data, comprised of people’s own voices on issues that are of concern to them. Aims: To explore the impact of stroke and aphasia on a person’s relationships with family, friends and the wider network through analysing blogs written by people with aphasia. Methods & Procedures: Blog search engines were used to identify blogs sustained by a sole author who had aphasia following a stroke, and which reflected on their social network. The data were analysed qualitatively using framework analysis. Outcomes & Results: The systematic search resulted in 10 relevant blogs. Participants were aged between 26 and 69 years old, lived in the community, were at least 1 year post stroke and included six women and four men. Aphasia was a consistent thread running through the blogs affecting conversations with all parts of a person’s network and impacting on participants’ sense of self. They found it more difficult to take part in family activities and described higher degrees of dependence and changed family dynamics. Contact with friends was reduced, partly due to communication and physical difficulties. While some participants became motivated to become members of groups post stroke, contact with the wider network sometimes diminished, in part because of loss of work and community activities. An additional factor impacting on social relationships was other people’s positive or negative reaction towards the person with aphasia. Finally, the blogs reflected on the importance of support they had received, both from close family and also from the wider community. Conclusions: This study found that social relationships played a crucial role in people’s lives following a stroke and aphasia. Nonetheless, family relationships, friendships and social exchanges within the wider social network were all substantially affected. Exploring this area through online narratives offered a rich and highly authentic source of data. The findings suggest that clinicians should incorporate social approaches in rehabilitation and consider ways to foster the maintenance of social networks. The use of social media by people with aphasia should be further explored, both as a therapeutic outlet and also as a way for people with aphasia to feel connected to a wider community

A systematic review of the impact of stroke on social support and social networks: associated factors and patterns of change

Objective: Identify what factors are associated with functional social support and social network post stroke; explore stroke survivors’ perspectives on what changes occur and how they are perceived. Data sources: The following electronic databases were systematically searched up to May 2015: Academic Search Complete; CINAHL Plus; E-journals; Health Policy Reference Centre; MEDLINE; PsycARTICLES; PsycINFO; and SocINDEX. Review methods: PRISMA guidelines were followed in the conduct and reporting of this review. All included studies were critically appraised using the Critical Appraisal Skills Program tools. Meta-ethnographic techniques were used to integrate findings from the qualitative studies. Given the heterogeneous nature of the quantitative studies, data synthesis was narrative. Results: 70 research reports met the eligibility criteria: 22 qualitative and 48 quantitative reporting on 4,816 stroke survivors. The qualitative studies described a contraction of the social network, with non-kin contact being vulnerable. Although family were more robust network members, significant strain was observed within the family unit. In the quantitative studies, poor functional social support was associated with depression (13/14 studies), reduced quality of life (6/6 studies) and worse physical recovery (2/2 studies). Reduced social network was associated with depression (7/8 studies), severity of disability (2/2 studies) and aphasia (2/2 studies). Although most indicators of social network reduced post stroke (for example, contact with friends, 5/5 studies), the perception of feeling supported remained relatively stable (4/4 studies). Conclusion: Following a stroke non-kin contact is vulnerable, strain is observed within the family unit, and poor social support is associated with depressive symptoms