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The residual closure of a subgroup H of a group G is the intersection of all virtually normal subgroups of G containing H. We show that if G is generated by finitely many cosets of H and if H is commensurated, then the residual closure of H in G is virtually normal. This implies that separable commensurated subgroups of finitely generated groups are virtually normal. A stream of applications to separable subgroups, polycyclic groups, residually finite groups, groups acting on trees, lattices in products of trees and just-infinite groups then flows from this main result.
Certain ways of responding to psychotic experiences (PEs) appear more commonly associated with clinical distress (e.g. avoidance) and other ways with benign or positive outcomes (e.g. reappraisal and acceptance). Past research has largely been limited to retrospective self-report. We aimed to compare clinical and non-clinical individuals on experimental analogues of anomalous experiences.
Response styles of two groups with persistent PEs (clinical n = 84; non-clinical n = 92) and a control group without PEs (n = 83) were compared following experimental analogues of thought interference (Cards Task, Telepath) and hearing voices (Virtual Acoustic Space Paradigm).
The non-clinical group with PEs were less likely to endorse unhelpful response styles, such as passive responding or attempts to avoid, suppress, worry about or control mental experiences, compared with the clinical group on all three tasks. The clinical group were more likely to endorse unhelpful response styles compared with controls on two out of three tasks (Cards Task and Telepath). The non-clinical group performed similarly to controls on unhelpful responding across all tasks. There were no group differences for helpful response styles, such as cognitive reappraisal or mindful acceptance of experiences.
In line with cognitive models of psychosis, the findings suggest that the way in which individuals respond to unusual experiences may be an important factor in understanding clinical distress, supporting the therapeutic rationale of targeting potentially unhelpful patterns of response.
We summarize the findings from an interlaboratory study conducted between ten international research groups and investigate the use of the commonly used maximum separation distance and local concentration thresholding methods for solute clustering quantification. The study objectives are: to bring clarity to the range of applicability of the methods; identify existing and/or needed modifications; and interpretation of past published data. Participants collected experimental data from a proton-irradiated 304 stainless steel and analyzed Cu-rich and Ni–Si rich clusters. The datasets were also analyzed by one researcher to clarify variability originating from different operators. The Cu distribution fulfills the ideal requirements of the maximum separation method (MSM), namely a dilute matrix Cu concentration and concentrated Cu clusters. This enabled a relatively tight distribution of the cluster number density among the participants. By contrast, the group analysis of the Ni–Si rich clusters by the MSM was complicated by a high Ni matrix concentration and by the presence of Si-decorated dislocations, leading to larger variability among researchers. While local concentration filtering could, in principle, tighten the results, the cluster identification step inevitably maintained a high scatter. Recommendations regarding reporting, selection of analysis method, and expected variability when interpreting published data are discussed.
This study, based on vegetable production fields, combined soil quality assessed by three approaches (qualitatively by farmers, semi-quantitatively by a researcher and quantitatively by laboratory analyses) with the aim of improving the integration of the different approaches. We interviewed 79 peri-urban vegetable growers in two communities within the Sunyani Municipality, Ghana. Eight of the farmers were selected to participate in the farmer-based assessment of soil quality. Further, visual evaluation of soil quality was conducted by the researcher, followed by laboratory analyses of soil properties to corroborate the farmers’ assessment of good and poor soils in their fields. Results showed that the farmers used locally-defined characteristics to describe the physical, biological and crop performance indicators of soil quality. There was, in general, limited use and understanding of soil chemical properties as indicators of soil quality. The farmers’ perception on soil quality of their fields largely influenced their decision on the type of crops they cultivate, and application regimes of mineral fertilizers. Results from the visual evaluation by the researcher agreed in some respects with the farmers’ assessment of soil quality of the good and poor soils in their respective farms. Laboratory analyses did not show specific trends for the content of chemical properties for neither good nor poor soils. The study highlighted that none of the approaches of soil quality assessment is necessarily superior in and of itself. We emphasized the need for integration to capitalize on the strengths of each approach, enhance mutual learning between farmers and soil scientists, build the capacity of farmers, and improve their decision on soil use for agricultural production.
People with psychotic disorders account for most acute admissions to psychiatric wards. Psychological therapies are a treatment adjunct to standard medication and nursing care, but the evidence base for such therapies within in-patient settings is unclear.
To conduct a systematic scoping review of the current evidence base for psychological therapies for psychosis delivered within acute in-patient settings (PROSPERO: CRD42015025623).
All study designs, and therapy models, were eligible for inclusion in the review. We searched PubMed, PsycINFO, EThOS, ProQuest, conference abstracts and trial registries.
We found 65 studies that met criteria for inclusion in the review, 21 of which were randomised controlled trials (RCTs). The majority of studies evaluated cognitive–behavioural interventions. Quality was variable across all study types. The RCTs were mostly small (n<25 in the treatment arm), and many had methodological limitations including poorly described randomisation methods, inadequate allocation concealment and non-masked outcome assessments. We found studies used a wide range of different outcome measures, and relatively few studies reported affective symptoms or recovery-based outcomes. Many studies described adaptations to treatment delivery within in-patient settings, including increased frequency of sessions, briefer interventions and use of single-session formats.
Based on these findings, there is a clear need to improve methodological rigour within in-patient research. Interpretation of the current evidence base is challenging given the wide range of different therapies, outcome measures and models of delivery described in the literature.
Hearing voices can be a distressing and disabling experience for some, whilst it is a valued experience for others, so-called ‘healthy voice-hearers’. Cognitive models of psychosis highlight the role of memory, appraisal and cognitive biases in determining emotional and behavioural responses to voices. A memory bias potentially associated with distressing voices is the overgeneral memory bias (OGM), namely the tendency to recall a summary of events rather than specific occasions. It may limit access to autobiographical information that could be helpful in re-appraising distressing experiences, including voices.
We investigated the possible links between OGM and distressing voices in psychosis by comparing three groups: (1) clinical voice-hearers (N = 39), (2) non-clinical voice-hearers (N = 35) and (3) controls without voices (N = 77) on a standard version of the autobiographical memory test (AMT). Clinical and non-clinical voice-hearers also completed a newly adapted version of the task, designed to assess voices-related memories (vAMT).
As hypothesised, the clinical group displayed an OGM bias by retrieving fewer specific autobiographical memories on the AMT compared with both the non-clinical and control groups, who did not differ from each other. The clinical group also showed an OGM bias in recall of voice-related memories on the vAMT, compared with the non-clinical group.
Clinical voice-hearers display an OGM bias when compared with non-clinical voice-hearers on both general and voices-specific recall tasks. These findings have implications for the refinement and targeting of psychological interventions for psychosis.
Symptoms of anxiety are prevalent in Major Depressive Disorder (MDD) and are associated with greater illness severity, suicidality, impaired functioning and poor response to antidepressant treatment (ADT). In MDD, anxiety symptoms can be assessed as ‘anxious distress’ (new DSM-5 specifier) or ‘anxious depression’ (score ≥7 on the HAM-D anxiety/somatization factor). Brexpiprazole is a serotonin–dopamine activity modulator that is a partial agonist at 5-HT1A and dopamine D2 receptors, and an antagonist at 5-HT2A and noradrenaline alpha1B/2C receptors – all at similar potency. Brexpiprazole is approved in the US for treatment ofschizophrenia, and as adjunctive treatment in MDD. The objective of this post-hoc analysis was to assess the efficacy of brexpiprazole as adjunct to ADT in patients with MDDand anxiety symptoms, using these two definitions of anxiety.
Data were pooled from three randomized, double-blind, placebo-controlled studies with similar designs (Pyxis – NCT01360645; Polaris – NCT01360632; Sirius – NCT02196506). In each study, patients with MDD and an inadequate response to 1–3 ADTs received single-blind ADT for 8 weeks. Patients with inadequate response throughout this prospective phase were randomized to receive either ADT+brexpiprazole (2mg in Pyxis and Sirius; 1mg or 3 mg in Polaris) or ADT+placebo for 6 weeks. Proxies used to categorize patients as having ‘anxious distress’ included a score of ≥2 on the following symptoms at randomization: tension (MADRS item 3 score ≥3); restlessness (IDS item 24 score ≥2); concentration (MADRS item 6 score ≥3); or apprehension (HAM-D item 10 score ≥3). Scores on the items of the HAM-D anxiety/somatization factor at randomization (baseline) were used to identify patients with ‘anxious depression’. Efficacy was assessed as the change in MADRS total score from baseline to Week 6. Statistical analysis used a Mixed Model Repeated Measure approach using pooled brexpiprazole doses.
After 8 weeks of prospective ADT monotherapy, 57.6% (n=797/1,383) of patients met the criteria for anxious distress, and 48.5% (n=671/1,383) for anxious depression. The mean MADRS total score was 29.0 for patients with anxious distress in the adjunctive brexpiprazole (n=462) group and 29.1 in the placebo (n=327) group; while those with anxious depression were 28.9 (brexpiprazole; n=384) and 28.6 (placebo; n=282). Compared to those receiving placebo, patients with both anxious distress and anxious depression who received adjunctive brexpiprazole showed a greater improvement in MADRS total score (LS mean difference -2.38, p=0.0001 and -1.68, p=0.012, respectively). These improvements, compared to placebo, were similar to those in patients who had not met the criteria for anxious distress (-1.40, p=0.023) or anxious depression (-2.17, p<0.001).
Adjunctive brexpiprazole may be efficacious in reducing depressive symptoms both in patients with or without symptoms of anxiety.
The studies were funded by H. Lundbeck A/S and Otsuka Pharmaceutical Development & Commercialization, Inc.
Acting on harmful command hallucinations is a major clinical concern. Our COMMAND CBT trial approximately halved the rate of harmful compliance (OR = 0.45, 95% CI 0.23–0.88, p = 0.021). The focus of the therapy was a single mechanism, the power dimension of voice appraisal, was also significantly reduced. We hypothesised that voice power differential (between voice and voice hearer) was the mediator of the treatment effect.
The trial sample (n = 197) was used. A logistic regression model predicting 18-month compliance was used to identify predictors, and an exploratory principal component analysis (PCA) of baseline variables used as potential predictors (confounders) in their own right. Stata's paramed command used to obtain estimates of the direct, indirect and total effects of treatment.
Voice omnipotence was the best predictor although the PCA identified a highly predictive cognitive-affective dimension comprising: voices’ power, childhood trauma, depression and self-harm. In the mediation analysis, the indirect effect of treatment was fully explained by its effect on the hypothesised mediator: voice power differential.
Voice power and treatment allocation were the best predictors of harmful compliance up to 18 months; post-treatment, voice power differential measured at nine months was the mediator of the effect of treatment on compliance at 18 months.
The success of scaling out depends on a clear understanding of the factors that affect adoption of grain legumes and account for the dynamism of those factors across heterogeneous contexts of sub-Saharan Africa. We reviewed literature on adoption of grain legumes and other technologies in sub-Saharan Africa and other developing countries. Our review enabled us to define broad factors affecting different components of the scaling out programme of N2Africa and the scales at which those factors were important. We identified three strategies for managing those factors in the N2Africa scaling out programme: (i) testing different technologies and practices; (ii) evaluating the performance of different technologies in different contexts; and (iii) monitoring factors that are difficult to predict. We incorporated the review lessons in a design to appropriately target and evaluate technologies in multiple contexts across scales from that of the farm to whole countries. Our implementation of this design has only been partially successful because of competing reasons for selecting activity sites. Nevertheless, we observe that grain legume species have been successfully targeted for multiple biophysical environments across sub-Saharan Africa, and to social and economic contexts within countries. Rhizobium inoculant and legume specific fertiliser blends have also been targeted to specific contexts, although not in all countries. Relatively fewer input and output marketing models have been tested due to public–private partnerships, which are a key mechanism for dissemination in the N2Africa project.
Review efficacy, safety, and tolerability of brexpiprazole in patients with schizophrenia in short- and long-term phase 3 studies.
Patients experiencing a current exacerbation of schizophrenia received brexpiprazole in two fixed-dose (2 and 4 mg), 6-week, placebo-controlled studies, one flexible-dose (2–4 mg), 6-week, placebo-control and active reference study, and one fixed-dose (1–4 mg), 52-week, placebo-controlled maintenance study.
The efficacy of brexpiprazole was demonstrated in the two short-term fixed-dose studies with statistically significant improvements from baseline in Positive and Negative Syndrome Scale (PANSS) total score compared with placebo. In the flexible-dose short-term study, treatment with brexpiprazole resulted in numerically greater improvements in PANSS total score than with placebo that approached statistical significance (p=0.056). A meta-analysis of these short-term studies showed a mean change in PANSS total score of −20.1, reflecting a clinically meaningful reduction in symptoms. In the maintenance study, brexpiprazole had a beneficial effect relative to placebo on time to exacerbation of psychotic symptoms/impending relapse (p<0.0001). For all studies, brexpiprazole demonstrated clinically meaningful treatment effects on the Personal and Social Performance scale. Brexpiprazole had a favourable safety profile, with a relatively low prevalence of activating and sedating side effects. Weight gain in the short-term studies was ~1 kg greater than placebo. No safety concerns were observed with brexpiprazole in laboratory values, electrocardiogram, or vital signs.
Overall, the results indicate brexpiprazole, used either short-term or as part of a long-term maintenance treatment programme, is an efficacious therapy option in adults with schizophrenia and has a favourable safety/tolerability profile.
I will not say much about autobiography in South Africa because it’s a given. It’s the kind of thing that has emerged naturally from South African conditions, and in fact, we are seeing it emerge all over Africa as a literature of self-definition. It has become a peculiar genre in Africa, a genre that depicts the very social conditions that have given rise to it.
My remarks this morning will be concerned mostly with the novel. This is a more problematic genre in South Africa than in other parts of Africa, and we may need a long time to debate and discuss the issues surrounding it.
Before I go on, however, I would like to add to what Mazisi said this morning, even though it is not connected with my talk. I want to say this by way of preface. Since we are talking about South Africa, we need to know that we are talking about African people rather than about ethnic groups, rather than about “tribes.”
We have investigated the tribomechanical properties of ion-beam-densified sol-gel zirconia overlayers on bulk zirconia. Ion irradiation of the sol-gel films leads to hydrogen, oxygen, and carbon losses as indicated by Rutherford backscattering spectrometry and forward recoil energy spectroscopy. Ellipsometry measurements show that the film thickness decreases with increasing dose. The microhardness exhibits an increase and subsequent decrease with dose. Friction measurements along with profilometry measurements indicate that severe abrasive wear of the film takes place in the first 1000 cycles after which point the substrate is in direct contact with the pin.
The main objective of the simplicity model of unsupervised categorization is to predict the relative intuitiveness of different classifications of items, based on their similarity. The model derives from the minimum description length framework, which is an algorithmic formalization of Ockham's razor. It generally prefers classifications which maximize within- category similarity, while minimizing between-category similarity.
Description of the model
The simplicity model of categorization can be viewed as one route to the formalization of Rosch and Mervis's (1975) proposal concerning the nature of ‘basic level’ categories, that is, the categories with which we prefer to classify objects (as opposed to corresponding superordinate or subordinate categories). According to Rosch and Mervis, basic level categories are those that maximize within-category similarity and minimize between-category similarity. Pothos and Chater (2002) examined whether this proposal may be suitable for predicting category preference generally, within a computational framework based on the simplicity principle.
The application of the simplicity principle in psychology has its origins in theories of perception (e.g., Hochberg & McAlister, 1953; Mach, 1959/1906). Informally, the simplicity principle states that simple explanations should be preferred – here ‘explanation’ refers to a pattern or structure in the data. The intuition is that the degree to which a pattern is suggested by the data can be quantified by assessing how briefly the data can be encoded, using that pattern.
The science of extra-solar planets is one of the most rapidly changing areas of astrophysics and since 1995 the number of planets known has increased by almost two orders of magnitude. A combination of ground-based surveys and dedicated space missions has resulted in 560-plus planets being detected, and over 1200 that await confirmation. NASA's Kepler mission has opened up the possibility of discovering Earth-like planets in the habitable zone around some of the 100,000 stars it is surveying during its 3 to 4-year lifetime. The new ESA's Gaia mission is expected to discover thousands of new planets around stars within 200 parsecs of the Sun. The key challenge now is moving on from discovery, important though that remains, to characterisation: what are these planets actually like, and why are they as they are?
In the past ten years, we have learned how to obtain the first spectra of exoplanets using transit transmission and emission spectroscopy. With the high stability of Spitzer, Hubble, and large ground-based telescopes the spectra of bright close-in massive planets can be obtained and species like water vapour, methane, carbon monoxide and dioxide have been detected. With transit science came the first tangible remote sensing of these planetary bodies and so one can start to extrapolate from what has been learnt from Solar System probes to what one might plan to learn about their faraway siblings. As we learn more about the atmospheres, surfaces and near-surfaces of these remote bodies, we will begin to build up a clearer picture of their construction, history and suitability for life.
The Exoplanet Characterisation Observatory, EChO, will be the first dedicated mission to investigate the physics and chemistry of Exoplanetary Atmospheres. By characterising spectroscopically more bodies in different environments we will take detailed planetology out of the Solar System and into the Galaxy as a whole.
EChO has now been selected by the European Space Agency to be assessed as one of four M3 mission candidates.