Mass-independent scheme for enhancing spatial quantum superpositions

Placing a large mass in a large spatial superposition, such as a Schrödinger cat state, is a significant and important challenge. In particular, the large spatial superposition [O(10-100)μm] of mesoscopic masses [m∼O(10-14-10-15)kg] makes it possible to test the quantum nature of gravity via entanglement in the laboratory. To date, the proposed methods of achieving this spatial delocalization are to use wave-packet expansions or quantum ancilla- (for example, spin-) dependent forces, all of whose efficacy reduces with mass. Thus increasing the spatial splitting independently of the mass is an important open challenge. In this paper we present a method of achieving a mass-independent enhancement of superposition via diamagnetic repulsion from current-carrying wires. We analyze an example system which uses the Stern-Gerlach effect to creating a small initial splitting and then apply our diamagnetic repulsion method to enhance the superposition size O(400-600)μm from an initial modest split of the wave function. We provide an analytical and numerical analysis of our scheme

Relative Acceleration Noise Mitigation for Nanocrystal Matter-wave Interferometry: Application to Entangling Masses via Quantum Gravity

Matter wave interferometers with large momentum transfers, irrespective of specific implementations, will face a universal dephasing due to relative accelerations between the interferometric mass and the associated apparatus. Here we propose a solution that works even without actively tracking the relative accelerations: putting both the interfering mass and its associated apparatus in a freely falling capsule, so that the strongest inertial noise components vanish due to the equivalence principle. In this setting, we investigate two of the most important remaining noise sources: (a) the non-inertial jitter of the experimental setup and (b) the gravity-gradient noise. We show that the former can be reduced below desired values by appropriate pressures and temperatures, while the latter can be fully mitigated in a controlled environment. We finally apply the analysis to a recent proposal for testing the quantum nature of gravity [S. Bose et. al. Phys. Rev. Lett 119, 240401 (2017)] through the entanglement of two masses undergoing interferometry. We show that the relevant entanglement witnessing is feasible with achievable levels of relative acceleration noise

Improving Continuous-variable Quantum Channels with Unitary Averaging

A significant hurdle for quantum information and processing using bosonic systems are stochastic phase errors, which are likely to occur as the photons propagate through a channel. We propose and demonstrate a scheme of passive, linear optical unitary averaging for protecting Gaussian channels. The scheme requires only linear optical elements and vacuum detectors, and protects against a loss of purity, squeezing and entanglement. We present numerical simulations and analytical formula, tailored for currently relevant parameters with low noise levels, where our approximations perform exceptionally well. We also show the asymptotic nature of the protocol, highlighting both current and future relevance.Comment: 6 pages, 7 figures, 1 tabl

Home-based toothbrushing interventions for parents of young children to reduce dental caries: A systematic review

Background: Dental caries is the most prevalent preventable condition in children. A key preventive home-based oral health behaviour is the adoption and maintenance of parental supervised toothbrushing until eight years of age. Aim: To examine interventions promoting parental supervised toothbrushing practices to reduce dental caries in young children (<8 years old). Design: Interventions promoting parental involvement in home-based toothbrushing in children under eight years old and their impact on caries were subjected to review. Electronic databases (MEDLINE, EMBASE, PubMed, Web of Science, PsycINFO, Scopus and the Cochrane Library), references and unpublished literature databases were searched for relevant literature. Results: Of the 10,176 articles retrieved, forty-two articles were included. The Theoretical Domains Framework was used to code intervention content, with the main domains addressed being knowledge (41/42), skills (35/42), and environmental context and resources (22/42). Sufficient descriptions of the intervention development, delivery and evaluation were lacking, with only 18 studies being underpinned by theory. Twenty-nine studies explored the impact on caries yielding mixed results. Conclusions: There are few interventions targeting home-based oral health behaviours underpinned by theory and methodological rigour in their development and evaluation. This demonstrates a clear need for future interventions to be guided by complex intervention methodology

Development and testing of a Cognitive Behavioural Therapy resource for children's dental anxiety

Cognitive Behavioral Therapy (CBT) is an evidence-based treatment for dental anxiety; however, access to therapy is limited. The current study aimed to develop a self-help CBT resource for reducing dental anxiety in children, and to assess the feasibility of conducting a trial to evaluate the treatment efficacy and cost-effectiveness of such an intervention. A mixed methods design was employed. Within phase 1, a qualitative “person-based” approach informed the development of the self-help CBT resource. This also employed guidelines for the development and evaluation of complex interventions. Within phase 2, children, aged between 9 and 16 y, who had elevated self-reported dental anxiety and were attending a community dental service or dental hospital, were invited to use the CBT resource. Children completed questionnaires, which assessed their dental anxiety and health-related quality of life (HRQoL) prior to and following their use of the resource. Recruitment and completion rates were recorded. Acceptability of the CBT resource was explored using interviews and focus groups with children, parents/carers and dental professionals. For this analysis, the authors adhered to the Mixed Methods Appraisal Tool criteria. There were 24 families and 25 dental professionals participating in the development and qualitative evaluation of the CBT resource for children with dental anxiety. A total of 56 children agreed to trial the CBT resource (66% response rate) and 48 of these children completed the study (86% completion rate). There was a significant reduction in dental anxiety (mean score difference = 7.7, t = 7.9, df = 45, P < 0.001, Cohen’s d ES = 1.2) and an increase in HRQoL following the use of the CBT resource (mean score difference = -0.03, t = 2.14, df = 46, P < 0.05, Cohen’s d ES = 0.3). The self-help approach had high levels of acceptability to stakeholders. These findings provide preliminary evidence for the effectiveness and acceptability of the resource in reducing dental anxiety in children and support the further evaluation of this approach in a randomized control trial

Participant recruitment to FiCTION, a primary dental care trial – survey of facilitators and barriers

Objective To identify reasons behind a lower than expected participant recruitment rate within the FiCTION trial, a multi-centre paediatric primary dental care randomised controlled trial (RCT). Subjects (materials) and methods An online survey, based on a previously published tool, consisting of both quantitative and qualitative responses, completed by staff in dental practices recruiting to FiCTION. Ratings from quantitative responses were aggregated to give overall scores for factors related to participant recruitment. Qualitative responses were independently grouped into themes. Results Thirty-nine anonymous responses were received. Main facilitators related to the support received from the central research team and importance of the research question. The main barriers related to low child eligibility rates and the integration of trial processes within routine workloads. Conclusions These findings have directed strategies for enhancing participant recruitment at existing practices and informed recruitment of further practices. The results help provide a profile of the features required of practices to successfully screen and recruit participants. Future trials in this setting should consider the level of interest in the research question within practices, and ensure trial processes are as streamlined as possible. Research teams should actively support practices with participant recruitment and maintain enthusiasm among the entire practice team

Health visiting teams and children’s oral health: a scoping review

Background Recent policies have recommended early-life interventions to prevent caries. The four nations of the UK each have a national universal children’s health programme, through which health visitors and their wider team (HVTs) promote health in the early years. HVT visits offer an opportunity to support parents to improve their child’s oral health. A scoping review was conducted to provide a descriptive synthesis of the current literature related to the role of HVTs in improving the oral health of children 0–5 years old and to identify significant gaps for future research. This review informed the feasibility study of the First Dental Steps Intervention, a targeted health visitor-led infant oral health intervention in England. Methods Electronic database searches for peer-reviewed literature were performed using Medline via Ovid and Web of Science (1946–2021). The quality of included intervention studies was assessed using the Effective Public Health Practice Project tool. Additionally, a grey literature search was conducted (key organisations, bibliographic and thesis databases, forwards and backwards citation, Google). Results Thirty-nine publications, published between 1980 and 2021, were included. The majority of included papers were from the UK. The quality of intervention studies (n = 7) ranged from weak to strong. Thematic analysis identified the following themes: (1) professional knowledge, education, and training; (2) involvement of HVs in the delivery of oral health interventions; (3) effectiveness of interventions; (4) perspectives of HVs providing oral health advice and acceptability; and (5) barriers and facilitators to promoting oral health. The grey literature search identified 125 sources. HVT involvement was reported in a variety of source types: reports, guidance documents, evaluations, reviews, and training resources. HVTs were involved in oral health by providing oral health packs, brushing and oral health advice, registration and attendance, oral health training, risk assessment, and referral to dental services. Conclusion The current literature suggests that HVTs are well placed to improve children’s oral health. Facilitators and barriers are encountered by HVTs in promoting oral health which should be considered by commissioners. There is a need for future high-quality studies that address the inadequacies found and provide further evidence of the effectiveness of HVT’s oral health interventions

Study protocol for First Dental Steps Intervention: feasibility study of a health visitor led infant oral health improvement programme.

BACKGROUND: Dental caries in childhood is a burden on the daily lives of children and their families, and associated with poor oral health in adulthood. In England, dental caries is the most common reason for young children to be admitted to hospital. It is believed that most tooth extractions (due to decay) for children aged 10 years and under, could be avoided with improved prevention and early management. National public health policy recommendations in England include specific oral health initiatives to tackle tooth decay. One of these initiatives is delivered as part of the Healthy Child Programme and includes providing workforce training in oral health, integrating oral health advice into home visits, and the timely provision of fluoride toothpaste. This protocol seeks to assess the delivery of the First Dental Steps intervention and uncertainties related to the acceptability, recruitment, and retention of participants. METHODS: This study seeks to explore the feasibility and acceptability of the First Dental Steps intervention and research methods. First Dental Steps intervention will be delivered in local authority areas in South West England and includes oral health training for health visitors (or community nursery nurses) working with 0-5-year-olds and their families. Further, for vulnerable families, integrating oral health advice and the provision of an oral health pack (including a free flow cup, an age appropriate toothbrush, and 1450 ppm fluoride toothpaste) during a mandated check by a health visitor. In this study five local authority areas will receive the intervention. Interviews with parents receiving the intervention and health visitors delivering the intervention will be undertaken, along with a range of additional interviews with stakeholders from both intervention and comparison sites (four additional local authority areas). DISCUSSION: This protocol was written after the start of the COVID-19 pandemic, as a result, some of the original methods were adjusted specifically to account for disruptions caused by the pandemic. Results of this study will primarily provide evidence on the acceptability and feasibility of both the First Dental Steps intervention and the research methods from the perspective of both families and stakeholders