121 research outputs found

    Automata with Nested Pebbles Capture First-Order Logic with Transitive Closure

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    String languages recognizable in (deterministic) log-space are characterized either by two-way (deterministic) multi-head automata, or following Immerman, by first-order logic with (deterministic) transitive closure. Here we elaborate this result, and match the number of heads to the arity of the transitive closure. More precisely, first-order logic with k-ary deterministic transitive closure has the same power as deterministic automata walking on their input with k heads, additionally using a finite set of nested pebbles. This result is valid for strings, ordered trees, and in general for families of graphs having a fixed automaton that can be used to traverse the nodes of each of the graphs in the family. Other examples of such families are grids, toruses, and rectangular mazes. For nondeterministic automata, the logic is restricted to positive occurrences of transitive closure. The special case of k=1 for trees, shows that single-head deterministic tree-walking automata with nested pebbles are characterized by first-order logic with unary deterministic transitive closure. This refines our earlier result that placed these automata between first-order and monadic second-order logic on trees.Comment: Paper for Logical Methods in Computer Science, 27 pages, 1 figur

    DORSal: Diffusion for Object-centric Representations of Scenes et al

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    Recent progress in 3D scene understanding enables scalable learning of representations across large datasets of diverse scenes. As a consequence, generalization to unseen scenes and objects, rendering novel views from just a single or a handful of input images, and controllable scene generation that supports editing, is now possible. However, training jointly on a large number of scenes typically compromises rendering quality when compared to single-scene optimized models such as NeRFs. In this paper, we leverage recent progress in diffusion models to equip 3D scene representation learning models with the ability to render high-fidelity novel views, while retaining benefits such as object-level scene editing to a large degree. In particular, we propose DORSal, which adapts a video diffusion architecture for 3D scene generation conditioned on frozen object-centric slot-based representations of scenes. On both complex synthetic multi-object scenes and on the real-world large-scale Street View dataset, we show that DORSal enables scalable neural rendering of 3D scenes with object-level editing and improves upon existing approaches.Comment: Project page: https://www.sjoerdvansteenkiste.com/dorsa

    Validity of summing painful joint sites to assess joint-pain comorbidity in hip or knee osteoarthritis

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    BACKGROUND: Previous studies in patients with hip and knee osteoarthritis (OA) have advocated the relevance of assessing the number of painful joint sites, other than the primary affected joint, in both research and clinical practice. However, it is unclear whether joint-pain comorbidities can simply be summed up. METHODS: A total of 401 patients with hip or knee OA completed questionnaires on demographic variables and joint-pain comorbidities. Rasch analysis was performed to evaluate whether a sum score of joint-pain comorbidities can be calculated. RESULTS: Self-reported joint-pain comorbidities showed a good fit to the Rasch model and were not biased by gender, age, disease duration, BMI, or patient group. As a group, joint-pain comorbidities covered a reasonable range of severity levels, although the sum score had rather low reliability levels suggesting it cannot discriminate well among patients. CONCLUSIONS: Joint-pain comorbidities, in other than the primary affected joints, can be summed into a joint pain comorbidity score. Nevertheless, its use is discouraged for individual decision making purposes since its lacks discriminative power in patients with minimal or extreme joint pain

    The application of the tracer method with peer observation and formative feedback for professional development in clinical practice:a scoping review

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    INTRODUCTION: The tracer method, commonly used for quality assessment, can also be used as a tool for peer observation and formative feedback on professional development. This scoping review describes how, by whom, and with what effect the tracer method is applied as a formative professional development instrument between healthcare professionals of equal status and aims to identify the types of scientific evidence for this use of the tracer method. METHODS: The authors searched four electronic databases for eligible articles, which were screened and assessed for eligibility by two independent researchers. From eligible studies, data were extracted to summarize, collate, and make a narrative account of the findings. RESULTS: The electronic search yielded 1757 unique studies, eight of which were included as valid and relevant to our aim: five qualitative, two mixed methods, and one quantitative study. Seven studies took place in hospitals and one in general practice. The tracer method was used mainly as a form of peer observation and formative feedback. Most studies evaluated the tracer method’s feasibility and its impact on professional development. All but one study reported positive effects: participants described the tracer method generally as being valuable and worth continuing. DISCUSSION: Although the body of evidence is small and largely limited to the hospital setting, using the tracer method for peer observation and formative feedback between healthcare professionals of equal status appears sufficiently useful to merit further rigorous evaluation and implementation in continuous professional development in healthcare. SUPPLEMENTARY INFORMATION: The online version of this article (10.1007/s40037-021-00693-6) contains supplementary material, which is available to authorized users

    Impact and feasibility of a tailor-made patient communication quality improvement programme for hospital-based physiotherapists:a mixed-methods study

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    Background In tailoring a quality improvement programme for hospital-based physiotherapy, the original use of video recordings was replaced by using the tracer methodology. Objective To examine the impact of a tailor-made quality improvement programme addressing patient communication on the professional development of hospital-based physiotherapists, and to evaluate barriers and facilitators as determinants of feasibility of the programme. Methods A mixed-methods study was conducted. Participants were clustered in groups per hospital and linked with an equally sized group in a nearby hospital. Within the groups, fixed couples carried out a 2-hour tracer by directly observing each other's daily work routine. This procedure was repeated 6 months later. Data from feedback forms were analysed quantitatively, and a thematic analysis of transcripts from group interviews was conducted. Results Fifty hospital-based physiotherapists from 16 hospitals participated. They rated the impact of the programme on professional development, on a scale from 1 (much improvement needed) to 5 (no improvement needed), as 3.99 (SD 0.64) after the first tracer and 4.32 (SD 0.63) 6 months later; a mean improvement of 0.33 (95% CI 0.16 to 0.50). Participants scored, on a scale ranging from 1 to 5 on barriers and facilitators (feasibility), a mean of 3.45 (SD 0.95) on determinants of innovation, 3.47 (SD 0.86) on probability to use and 2.63 (SD 1.07) on the user feedback list. All participants emphasised the added value of the tracer methodology and mentioned effects on self-reflection and awareness most. Conclusions The tailor-made quality improvement programme, based on principles of the tracer methodology, was associated with a significant impact on professional development. Barriers and facilitators as determinants of feasibility of the programme showed the programme being feasible

    Quality aspects of hospital-based physiotherapy from the perspective of key stakeholders:a qualitative study

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    Background For the design of a robust quality system for hospital-based physiotherapy, it is important to know what key stakeholders consider quality to be. Objective To explore key stakeholders' views on quality of hospital-based physiotherapy. Methods We conducted 53 semi-structured interviews with 62 representatives of five key stakeholder groups of hospital-based physiotherapy: medical specialists, hospital managers, boards of directors, multidisciplinary colleagues and patients. Audio recordings of these interviews were transcribed verbatim and analysed with thematic analysis. Results According to the interviewees, quality of hospital-based physiotherapy is characterised by: (1) a human approach, (2) context-specific and up-to-date applicable knowledge and expertise, (3) providing the right care in the right place at the right time, (4) a proactive departmental policy in which added value for the hospital is transparent, (5) professional development and innovation based on a vision on science and developments in healthcare, (6) easy access and awareness of one's own and others' position within the interdisciplinary cooperation and (7) ensuring a continuum of care with the inclusion of preclinical and postclinical care of patients. Conclusions Important quality aspects in the perspective of all stakeholders were an expertise that matches the specific pathology of the patient, the hospital-based physiotherapist being a part of the care team, and the support and supervision of all patients concerning physical functioning during the hospitalisation period. Whereas patients mainly mentioned the personal qualities of the physiotherapist, the other stakeholders mainly focused on professional and organisational factors. The results of this study offer opportunities for hospital-based physiotherapy to improve the quality of provided care seen from the perspective of key stakeholders

    The influence of bias in randomized controlled trials on rehabilitation intervention effect estimates: what we have learned from meta-epidemiological studies

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    This study aimed to synthesize evidence from studies that addressed the influence of bias domains in randomized controlled trials on rehabilitation intervention effect estimates and discuss how these findings can maximize the trustworthiness of an RCT in rehabilitation. We screened studies about the influence of bias on rehabilitation intervention effect estimates published until June 2023. The characteristics and results of the included studies were categorized based on methodological characteristics and summarized narratively. We included seven studies with data on 227,806 RCT participants. Our findings showed that rehabilitation intervention effect estimates are likely exaggerated in trials with inadequate/unclear sequence generation and allocation concealment when using continuous outcomes. The influence of blinding was inconsistent and different from the rest of medical science, as meta-epidemiological studies showed overestimation, underestimation, or neutral associations for different types of blinding on rehabilitation treatment effect estimates. Still, it showed a more consistent pattern when looking at patient-reported outcomes. The impact of attrition bias and intention to treat has been analyzed only in two studies with inconsistent results. The risk of reporting bias seems to be associated with overestimation of treatment effects. Bias domains can influence rehabilitation treatment effects in different directions. The evidence is mixed and inconclusive due to the poor methodological quality of RCTs and the limited number and quality of studies looking at the influence of bias and treatment effects in rehabilitation. Further studies about the influence of bias in RCTs on rehabilitation intervention effect estimates are needed

    Topologies Refining the Cantor Topology on X ω

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    International audienceThe space of one-sided infinite words plays a crucial rôle in several parts of Theoretical Computer Science. Usually, it is convenient to regard this space as a metric space, the Cantor-space. It turned out that for several purposes topologies other than the one of the Cantor-space are useful, e.g. for studying fragments of first-order logic over infinite words or for a topological characterisation of random infinite words. It is shown that both of these topologies refine the topology of the Cantor-space. Moreover, from common features of these topologies we extract properties which characterise a large class of topologies. It turns out that, for this general class of topologies, the corresponding closure and interior operators respect the shift operations and also, to some respect, the definability of sets of infinite words by finite automata

    Therapeutic Validity and Effectiveness of Preoperative Exercise on Functional Recovery after Joint Replacement: A Systematic Review and Meta-Analysis

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    Background: Our aim was to develop a rating scale to assess the therapeutic validity of therapeutic exercise programmes. By use of this rating scale we investigated the therapeutic validity of therapeutic exercise in patients awaiting primary total joint replacement (TJR). Finally, we studied the association between therapeutic validity of preoperative therapeutic exercise and its effectiveness in terms of postoperative functional recovery. Methods: (Quasi) randomised clinical trials on preoperative therapeutic exercise in adults awaiting TJR on postoperative recovery of functioning within three months after surgery were identified through database and reference screening. Two reviewers extracted data and assessed the risk of bias and therapeutic validity. Therapeutic validity of the interventions was assessed with a nine-itemed, expert-based rating scale (scores range from 0 to 9; score ≥6 reflecting therapeutic validity), developed in a four-round Delphi study. Effects were pooled using a random-effects model and meta-regression was used to study the influence of therapeutic validity. Results: Of the 7,492 articles retrieved, 12 studies (737 patients) were included. None of the included studies demonstrated therapeutic validity and two demonstrated low risk of bias. Therapeutic exercise was not associated with 1) observed functional recovery during the hospital stay (Standardised Mean Difference [SMD]: −1.19; 95%-confidence interval [CI], −2.46 to 0.08); 2) observed recovery within three months of surgery (SMD: −0.15; 95%-CI, −0.42 to 0.12); and 3) self-reported recovery within three months of surgery (SMD −0.07; 95%-CI, −0.35 to 0.21) compared with control participants. Meta-regression showed no statistically significant relationship between therapeutic validity and pooled-effects. Conclusion: Preoperative therapeutic exercise for TJR did not demonstrate beneficial effects on postoperative functional recovery. However, poor therapeutic validity of the therapeutic exercise programmes may have hampered potentially beneficial effects, since none of the studies met the predetermined quality criteria. Future review studies on therapeutic exercise should address therapeutic validity. (aut.ref.

    Non-pharmacological care for patients with generalized osteoarthritis: design of a randomized clinical trial

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    <p>Abstract</p> <p>Background</p> <p>Non-pharmacological treatment (NPT) is a useful treatment option in the management of hip or knee osteoarthritis. To our knowledge however, no studies have investigated the effect of NPT in patients with generalized osteoarthritis (GOA). The primary aim of this study is to compare the effectiveness of two currently existing health care programs with different intensity and mode of delivery on daily functioning in patients with GOA. The secondary objective is to compare the cost-effectiveness of both interventions.</p> <p>Methods/Design</p> <p>In this randomized, single blind, clinical trial with active controls, we aim to include 170 patients with GOA. The experimental intervention consist of six self-management group sessions provided by a multi-disciplinary team (occupational therapist, physiotherapist, dietician and specialized nurse). The active control group consists of two group sessions and four sessions by telephone, provided by a specialized nurse and physiotherapist. Both therapies last six weeks. Main study outcome is daily functioning during the first year after the treatment, assessed on the Health Assessment Questionnaire. Secondary outcomes are health related quality of life, specific complaints, fatigue, and costs. Illness cognitions, global perceived effect and self-efficacy, will also be assessed for a responder analysis. Outcome assessments are performed directly after the intervention, after 26 weeks and after 52 weeks.</p> <p>Discussion</p> <p>This article describes the design of a randomized, single blind, clinical trial with a one year follow up to compare the costs and effectiveness of two non-pharmacological interventions with different modes of delivery for patients with GOA.</p> <p>Trial registration</p> <p>Dutch Trial Register NTR2137</p
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