Faraday pilot-wave dynamics in a circular corral

A millimetric droplet of silicone oil may bounce and self-propel on the free surface of a vertically vibrating fluid bath due to the droplet's interaction with its accompanying Faraday wave field. This hydrodynamic pilot-wave system exhibits many dynamics that were previously thought to be peculiar to the quantum realm. When the droplet is confined to a circular cavity, referred to as a 'corral', a range of dynamics may occur depending on the details of the geometry and the decay time of the subcritical Faraday waves. We herein present a theoretical investigation into the behaviour of subcritical Faraday waves in this geometry and explore the accompanying pilot-wave dynamics. By computing the Dirichlet-to-Neumann map for the velocity potential in the corral geometry, we can evolve the quasi-potential flow between successive droplet impacts, which, when coupled with a simplified model for the droplet's vertical motion, allows us to derive and implement a highly efficient discrete-time iterative map for the pilot-wave system. We study the onset of the Faraday instability, the emergence and quantisation of circular orbits and simulate the exotic dynamics that arises in smaller corrals

Vers des activités didactiques de mise au point de modèles de physique avec des micro-ordinateurs

Construire des activités scolaires utilisant l'ordinateur doit s'inspirer de l'évolution provoquée par l'introduction des ordinateurs dans les pratiques professionnelles en établissant des relations définissables et contrôlables avec ces " pratiques de références ". Deux caractéristiques générales de ces pratiques émergent : la prise en compte nécessaire de relations nouvelles avec le domaine empirique et l'utilisation d'une méthodologie de mise au point de modèles par approximations successives. En explorant dans les deux sens l'espace entre cadre scolaire et pratiques de référence, on élabore à la fois des outils pédagogiques (d'un autre ordre que les didacticiels) et des données utilisables pour la technique : c'est la base d'une méthodologie d'utilisation didactique des ordinateurs en physiqu

Anderson localization of walking droplets

Understanding the ability of particles to maneuver through disordered environments is a central problem in innumerable settings, from active matter and biology to electronics. Macroscopic particles ultimately exhibit diffusive motion when their energy exceeds the characteristic potential barrier of the random landscape. In stark contrast, wave-particle duality causes subatomic particles in disordered media to come to rest even when the potential is weak -- a remarkable phenomenon known as Anderson localization. Here, we present a hydrodynamic active system with wave-particle features, a millimetric droplet self-guided by its own wave field over a submerged random topography, whose dynamics exhibits localized statistics analogous to those of quantum systems. Consideration of an ensemble of particle trajectories reveals a suppression of diffusion when the guiding wave field extends over the disordered topography. We rationalize mechanistically the emergent statistics by virtue of the wave-mediated resonant coupling between the droplet and topography, which produces an attractive wave potential about the localization region. This hydrodynamic analog, which demonstrates how a classical particle may localize like a wave, suggests new directions for future research in various areas, including wave localization, many-body localization, and topological matter.Comment: Title changed, slight format change in figures, and text rewording, no changes to argument or result

Effect of plastic coating on the density of plasma formed in Si foil targets irradiated by ultra-high-contrast relativistic laser pulses

The formation of high energy density matter occurs in inertial confinement fusion, astrophysical, and geophysical systems. In this context, it is important to couple as much energy as possible into a target while maintaining high density. A recent experimental campaign, using buried layer (or "sandwich" type) targets and the ultrahigh laser contrast Vulcan petawatt laser facility, resulted in 500 Mbar pressures in solid density plasmas (which corresponds to about 4.6×107J/cm3 energy density). The densities and temperatures of the generated plasma were measured based on the analysis of X-ray spectral line profiles and relative intensities

Primary caregivers’ perceptions of factors influencing preschool children’s oral health: social practices perspective—a protocol for qualitative metasynthesis

Introduction The role of primary caregivers in setting the foundation for a child’s oral health throughout life is well recognised. Due to the dominant behaviour-based approach, research to date has mainly focused on exploring individual primary caregivers’ oral health knowledge and behaviours. A social science approach involving social practice theories moves beyond individual attitudes, behaviour and choices to offer a better understanding of the ways in which collective activity relates to health. This qualitative metasynthesis will involve an interpretive synthesis of data found in published qualitative literature from developed countries. The aim of the metasynthesis is to identify social practices in families from published qualitative research with caregivers on preschool children’s oral health. Methods and analysis This is a protocol for qualitative metasynthesis. The following databases will be used: MEDLINE, EMBASE, Global Health and Dentistry & Oral Sciences Source (DOSS) using the web-based database search platform Ovid, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Scopus. The research team has determined search strategies by using relevant key terms. Qualitative studies published in English language on family factors related to preschool children (aged 0–5 years) from developed countries (2022 United Nations classification) will be included. Qualitative data analysis will involve thematic analysis of the reported factors influencing oral health of preschool children, from the perspective of social practice theory. Researchers will use NVivo software for organising and managing the data. Ethics and dissemination No ethics approval is required, as this study does not involve human subjects. Findings will be disseminated through professional networks, conference presentations and submission to a peer-reviewed journal

Americomania and the French revolution debate in Britain, 1789-1802

This is one of several reviews of the same book to be published in this journal, to all of which the author will finally reply. Output Type: Book Revie

Aboriginal Health Worker perceptions of oral health: a qualitative study in Perth, Western Australia

Background: Improving oral health for Aboriginal Australians has been slow. Despite dental disease being largely preventable, Aboriginal Australians have worse periodontal disease, more decayed teeth and untreated dental caries than other Australians. Reasons for this are complex and risk factors include broader social and historic determinants such as marginalisation and discrimination that impact on Aboriginal people making optimum choices about oral health. This paper presents findings from a qualitative study conducted in the Perth metropolitan area investigating Aboriginal Health Workers’ (AHWs) perceptions of barriers and enablers to oral health for Aboriginal people. Methods: Following extensive consultation with Aboriginal stakeholders, researchers conducted semi-structured interviews and focus groups across 13 sites to investigate AHWs’ perceptions of barriers and enablers to oral health based on professional and personal experience. Responses from 35 AHWs were analysed independently by two researchers to identify themes that they compared, discussed, revised and organised under key themes. These were summarised and interrogated for similarities and differences with evidence in the literature. Results: Key findings indicated that broader structural and social factors informed oral health choices. Perceptions of barriers included cost of services and healthy diets on limited budgets, attending services for pain not prevention, insufficient education about oral health and preventing disease, public dental services not meeting demand, and blame and discrimination from some health providers. Suggested improvements included oral health education, delivering flexible services respectful of Aboriginal people, oral health services for 0–4 year olds and role modelling of oral health across generations. Conclusion: Reviewing current models of oral health education and service delivery is needed to reduce oral health disparities between Aboriginal and non-Aboriginal Australians. Shifting the discourse from blaming Aboriginal people for their poor oral health to addressing structural factors impacting on optimum oral health choices is important. This includes Aboriginal and non-Aboriginal stakeholders working together to develop and implement policies and practices that are respectful, well-resourced and improve oral health outcomes

Voting with their feet - predictors of discharge against medical advice in Aboriginal and non-Aboriginal ischaemic heart disease inpatients in Western Australia: an analytic study using data linkage

Background: Discharge Against Medical Advice (DAMA) from hospital is associated with adverse outcomes and is considered an indicator of the responsiveness of hospitals to the needs of Aboriginal and Torres Strait Islander Australians, the indigenous people of Australia. We investigated demographic and clinical factors that predict DAMA in patients experiencing their first-ever inpatient admission for ischaemic heart disease (IHD). The study focuse sparticularly on the differences in the risk of DAMA in Aboriginal and non-Aboriginal patients while also investigating other factors in their own right. Methods: A cross-sectional analytical study was undertaken using linked hospital and mortality data with complete coverage of Western Australia. Participants included all first-ever IHD inpatients (aged 25–79 years) admitted between 2005 and 2009, selected after a 15-year clearance period and who were discharged alive. The main outcome measure was DAMA as reflected in the hospital record. Multiple logistic regression was used to determine disparities in DAMA between Aboriginal and non-Aboriginal patients, adjusting for a range of demographic and clinical factors, including comorbidity based on 5-year hospitalization history. A series of additional models were run on subgroups of the cohort to refine the analysis. Ethics approval was granted by the WA Human Research and the WA Aboriginal Health Ethics Committees.Results: Aboriginal patients comprised 4.3% of the cohort of 37,304 IHD patients and 23% of the 224 DAMAs. Emergency admission (OR=5.9, 95% CI 2.9-12.2), alcohol admission history (alcohol-related OR=2.9, 95% CI 2.0-4.2) and Aboriginality (OR 2.3, 95% CI 1.5-3.5) were the strongest predictors of DAMA in the multivariate model. Patients living in rural areas while attending non-metropolitan hospitals had a 50% higher risk of DAMA than those living and hospitalised in metropolitan areas. There was consistency in the ORs for Aboriginality in the different multivariate models using restricted sub-cohorts and different Aboriginal identifiers. Sex, IHD diagnosis type and co-morbidity scores imparted different risks in Aboriginal versus non-Aboriginal patients. Conclusions: Understanding the risks and reasons for DAMA is important for health system policy and proactive management of those at risk of DAMA. Improving care to prevent DAMA should target unplanned admissions, rural hospitals and young men, Aboriginal people and those with alcohol and mental health comorbidities

Identifying barriers and improving communication between cancer service providers and Aboriginal patients and their families: the perspective of service providers

BACKGROUND: Aboriginal Australians experience poorer outcomes from cancer compared to the non-Aboriginal population. Some progress has been made in understanding Aboriginal Australians’ perspectives about cancer and their experiences with cancer services. However, little is known of cancer service providers’ (CSPs) thoughts and perceptions regarding Aboriginal patients and their experiences providing optimal cancer care to Aboriginal people. Communication between Aboriginal patients and non-Aboriginal health service providers has been identified as an impediment to good Aboriginal health outcomes. This paper reports on CSPs’ views about the factors impairing communication and offers practical strategies for promoting effective communication with Aboriginal patients in Western Australia (WA).METHODS: A qualitative study involving in-depth interviews with 62 Aboriginal and non-Aboriginal CSPs from across WA was conducted between March 2006 - September 2007 and April-October 2011. CSPs were asked to share their experiences with Aboriginal patients and families experiencing cancer. Thematic analysis was carried out. Our analysis was primarily underpinned by the socio-ecological model, but concepts of Whiteness and privilege, and cultural security also guided our analysis.RESULTS: CSPs’ lack of knowledge about the needs of Aboriginal people with cancer and Aboriginal patients’ limited understanding of the Western medical system were identified as the two major impediments to communication. For effective patient–provider communication, attention is needed to language, communication style, knowledge and use of medical terminology and cross-cultural differences in the concept of time. Aboriginal marginalization within mainstream society and Aboriginal people’s distrust of the health system were also key issues impacting on communication. Potential solutions to effective Aboriginal patient-provider communication included recruiting more Aboriginal staff, providing appropriate cultural training for CSPs, cancer education for Aboriginal stakeholders, continuity of care, avoiding use of medical jargon, accommodating patients’ psychosocial and logistical needs, and in-service coordination.CONCLUSION: Individual CSPs identified challenges in cross-cultural communication and their willingness to accommodate culture-specific needs within the wider health care system including better communication with Aboriginal patients. However, participants’ comments indicated a lack of concerted effort at the system level to address Aboriginal disadvantage in cancer outcomes

Infective endocarditis caused by methicillin-resistant Staphylococcus aureus in a young woman after ear piercing: a case report

<p>Abstract</p> <p>Introduction</p> <p>Ear piercing is a common practice among Korean adolescents and young women and usually is performed by nonmedical personnel, sometimes under suboptimal hygienic conditions. Consequently, ear piercing has been associated with various infectious complications, including fatal infective endocarditis. We report a case of infective endocarditis that was caused by community-associated methicillin-resistant <it>Staphylococcus aureus </it>after ear piercing and that was accompanied by a noticeable facial rash.</p> <p>Case presentation</p> <p>A 29-year-old Korean woman underwent ear piercing six days before hospitalization. On admission, she had fever, erythematous maculopapular rashes on her face, signs of generalized emboli, vegetation in her mitral valve, and methicillin-resistant <it>S. aureus </it>bacteremia. On the basis of the blood culture results, she was treated with vancomycin in combination with gentamicin. On day six of hospitalization, a rupture of the papillary muscle of her mitral valve developed, and emergency cardiac surgery replacing her mitral valve with a prosthetic valve was performed. After eight weeks of antibiotic therapy, she was treated successfully and discharged without significant sequelae.</p> <p>Conclusions</p> <p>Numerable cases of body piercing-related infective endocarditis have been reported, and since ear piercing is commonplace nowadays, the importance of risk recognition cannot be overemphasized. In our report, a patient developed infective endocarditis that was caused by methicillin-resistant <it>S. aureus </it>after ear piercing and that was accompanied by an interesting feature, namely facial rash.</p