Towards the graviton from spinfoams: higher order corrections in the 3d toy model

We consider the recent calculation gr-qc/0508124 of the graviton propagator in the spinfoam formalism. Within the 3d toy model introduced in gr-qc/0512102, we test how the spinfoam formalism can be used to construct the perturbative expansion of graviton amplitudes. Although the 3d graviton is a pure gauge, one can choose to work in a gauge where it is not zero and thus reproduce the structure of the 4d perturbative calculations. We compute explicitly the next to leading and next to next to leading orders, corresponding to one-loop and two-loop corrections. We show that while the first arises entirely from the expansion of the Regge action around the flat background, the latter receives contributions from the microscopic, non Regge-like, quantum geometry. Surprisingly, this new contribution reduces the magnitude of the next to next to leading order. It thus appears that the spinfoam formalism is likely to substantially modify the conventional perturbative expansion at higher orders. This result supports the interest in this approach. We then address a number of open issues in the rest of the paper. First, we discuss the boundary state ansatz, which is a key ingredient in the whole construction. We propose a way to enhance the ansatz in order to make the edge lengths and dihedral angles conjugate variables in a mathematically well-defined way. Second, we show that the leading order is stable against different choices of the face weights of the spinfoam model; the next to leading order, on the other hand, is changed in a simple way, and we show that the topological face weight minimizes it. Finally, we extend the leading order result to the case of a regular, but not equilateral, tetrahedron.Comment: 24 pages, many figure

Exploring incorporation of critical appraisal methods into rapid evidence reviews

Background: Cedar Healthcare Technology Centre produces rapid evidence reviews across a range of topics and regularly evaluates the methods implemented to improve the usefulness of outputs. Rapid evidence reviews typically omit components of a full systematic review to streamline the process. Where a review has short timelines, Cedar has made pragmatic decisions around critical appraisal (CA), such as only one reviewer appraising evidence, or providing a summary of key issues using checklists as a guide. To increase the level of trust in the findings and align with best practice, full checklist-based CA of studies was incorporated into rapid evidence review processes. Objectives: To explore the feasibility of incorporating checklist-based CA of studies into rapid evidence review processes to inform clinical commissioning decisions. Improving the robustness of rapid evidence review methodology is important to patients as it means commissioning decisions are based on the best available evidence. Methods: Joanna Briggs Institute (JBI) CA checklists were used to assess the quality of studies for two rapid evidence reviews produced in November 2022 and February 2023. CA was performed by one reviewer and verified by a second reviewer. The appraisal checklists were summarised and included as an appendix to the review. A narrative summary of the CA results was included in the main body of the report. Results: The inclusion of CA of all studies included in a rapid evidence review was an achievable task. However, it required additional resourcing and led to an increase in time to complete the review. Specifically, time was required to perform CA in duplicate, consider interpretation of checklist questions, discuss discrepancies, and narratively summarise the results. Conclusions: Including CA for studies included in a rapid evidence review is a valuable exercise to inform the reader of the quality of the evidence. Consequently, this can inform how trustworthy the evidence is and guide interpretation of the evidence to better inform clinical commissioning decisions. Patient, public, and/or healthcare consumer involvement: Healthcare consumers positively received inclusion of full checklist-based CA results, particularly where limited evidence existed on a topic, and considered it informative for making clinical commissioning decisions

Use of systematic review terminology and methodological quality in children’s social care

Purpose: What Works for Children’s Social Care has developed an ‘Evidence Store’ to improve awareness of evidence from systematic reviews in children’s social care. During review selection, some reviews were excluded due to methodological flaws, which this paper considers. Methods: Reviews were identified using a systematic search and screening process. Where reviews were identified as systematic reviews or meta-analyses, exclusion reasons were recorded and analysed. Results: The main methodological issue related to quality assessment, which was not conducted in the majority of cases. Several different types of quality assessment tools were used: scales, checklists, and domain-based approaches. Conclusions: This is the first study to examine the use of systematic review terminology in combination with the use of quality assessment tools in reviews in children’s social care. Consideration of appropriate systematic review methods will enable researchers to generate high quality evidence and support delivery of evidence-based care

Care-experienced cHildren and young peoples Interventions to improve Mental health and wEll-being outcomes: Systematic review (CHIMES) protocol

Introduction The mental health and well-being of children and young people who have been in care (ie, care-experienced) are a priority. There are a range of interventions aimed at addressing these outcomes, but the international evidence-base remains ambiguous. There is a paucity of methodologically robust systematic reviews of intervention effectiveness, with few considering the contextual conditions under which evaluations were conducted. This is important in understanding the potential transferability of the evidence-base across contexts. The present systematic review will adopt a complex systems perspective to synthesise evidence reporting evaluations of mental health and well-being interventions for care-experienced children and young people. It will address impact, equity, cost-effectiveness, context, implementation and acceptability. Stakeholder consultation will prioritise a programme theory, and associated intervention, that may progress to further development and evaluation in the UK. Methods and analysis We will search 16 bibliographic databases from 1990 to June 2020. Supplementary searching will include citation tracking, author recommendation, and identification of evidence clusters relevant to included evaluations. The eligible population is children and young people (aged ≤25 years) with experience of being in care. Outcomes are (1) mental, behavioural or neurodevelopmental disorders; (2) subjective well-being; (3) self-harm; suicidal ideation; suicide. Study quality will be appraised with methodologically appropriate tools. We will construct a taxonomy of programme theories and intervention types. Thematic synthesis will be used for qualitative data reporting context, implementation and acceptability. If appropriate, meta-analysis will be conducted with outcome and economic data. Convergent synthesis will be used to integrate syntheses of qualitative and quantitative data. Ethics and dissemination We have a comprehensive strategy for engagement with care-experienced children and young people, carers and social care professionals. Dissemination will include academic and non-academic publications and conference presentations. Ethical approval from Cardiff University’s School of Social Sciences REC will be obtained if necessary

A semiclassical tetrahedron

We construct a macroscopic semiclassical state state for a quantum tetrahedron. The expectation values of the geometrical operators representing the volume, areas and dihedral angles are peaked around assigned classical values, with vanishing relative uncertainties.Comment: 10 pages; v2 revised versio

Mental health and wellbeing related social support for care-experienced children and young people: A Scoping Review protocol of type, source and quality.

Existing literature shows that children and young people who have experienced statutory care are at risk of mental health issues and poorer wellbeing. Social support is associated with better mental health and wellbeing outcomes, with the potential to buffer the negative effects of stress and enable a person to thrive. This scoping review aims to understand and identify existing literature about mental health related social support for care-experienced children and young people to guide future practice, research and policy

Grasping rules and semiclassical limit of the geometry in the Ponzano-Regge model

We show how the expectation values of geometrical quantities in 3d quantum gravity can be explicitly computed using grasping rules. We compute the volume of a labelled tetrahedron using the triple grasping. We show that the large spin expansion of this value is dominated by the classical expression, and we study the next to leading order quantum corrections.Comment: 18 pages, 1 figur