Enhanced optoelectronic coupling for perovskite/silicon tandem solar cells.

Monolithic perovskite/silicon tandem solar cells are of great appeal as they promise high power conversion efficiencies (PCEs) at affordable cost. In state-of-the-art tandems, the perovskite top cell is electrically coupled to a silicon heterojunction bottom cell by means of a self-assembled monolayer (SAM), anchored on a transparent conductive oxide (TCO), which enables efficient charge transfer between the subcells1-3. Yet reproducible, high-performance tandem solar cells require energetically homogeneous SAM coverage, which remains challenging, especially on textured silicon bottom cells. Here, we resolve this issue by using ultrathin (5-nm) amorphous indium zinc oxide (IZO) as the interconnecting TCO, exploiting its high surface-potential homogeneity resulting from the absence of crystal grains and higher density of SAM anchoring sites when compared with commonly used crystalline TCOs. Combined with optical enhancements through equally thin IZO rear electrodes and improved front contact stacks, an independently certified PCE of 32.5% was obtained, which ranks among the highest for perovskite/silicon tandems. Our ultrathin transparent contact approach reduces indium consumption by approximately 80%, which is of importance to sustainable photovoltaics manufacturing4.

Comparing the clinical practice and prescribing safety of locum and permanent doctors: observational study of primary care consultations in England.

BACKGROUND: Temporary doctors, known as locums, are a key component of the medical workforce in the NHS but evidence on differences in quality and safety between locum and permanent doctors is limited. We aimed to examine differences in the clinical practice, and prescribing safety for locum and permanent doctors working in primary care in England. METHODS: We accessed electronic health care records (EHRs) for 3.5 million patients from the CPRD GOLD database with linkage to Hospital Episode Statistics from 1st April 2010 to 31st March 2022. We used multi-level mixed effects logistic regression to compare consultations with locum and permanent GPs for several patient outcomes including general practice revisits; prescribing of antibiotics; strong opioids; hypnotics; A&E visits; emergency hospital admissions; admissions for ambulatory care sensitive conditions; test ordering; referrals; and prescribing safety indicators while controlling for patient and practice characteristics. RESULTS: Consultations with locum GPs were 22% more likely to involve a prescription for an antibiotic (OR = 1.22 (1.21 to 1.22)), 8% more likely to involve a prescription for a strong opioid (OR = 1.08 (1.06 to 1.09)), 4% more likely to be followed by an A&E visit on the same day (OR = 1.04 (1.01 to 1.08)) and 5% more likely to be followed by an A&E visit within 1 to 7 days (OR = 1.05 (1.02 to 1.08)). Consultations with a locum were 12% less likely to lead to a practice revisit within 7 days (OR = 0.88 (0.87 to 0.88)), 4% less likely to involve a prescription for a hypnotic (OR = 0.96 (0.94 to 0.98)), 15% less likely to involve a referral (OR = 0.85 (0.84 to 0.86)) and 19% less likely to involve a test (OR = 0.81 (0.80 to 0.82)). We found no evidence that emergency admissions, ACSC admissions and eight out of the eleven prescribing safety indicators were different if patients were seen by a locum or a permanent GP. CONCLUSIONS: Despite existing concerns, the clinical practice and performance of locum GPs did not appear to be systematically different from that of permanent GPs. The practice and performance of both locum and permanent GPs is likely shaped by the organisational setting and systems within which they work.

Band Alignment and Surface Photo-Voltage Analysis of C-Si/Siox/Poly-Silicon Passivating-Contact Stacks Through X-Ray Photoelectron Spectroscopy.

Ultrathin SiOx layers and c-Si/SiOx interfaces find application in tunnel-oxide passivated contacts (TOPcon) for high-efficiency silicon solar cells. Here, we investigate their detailed microscopic properties, with specific attention for the case of c-Si(100) substrates, capped either by p-type or n-type poly-silicon layers [c-Si/SiOx/poly-Si (p+) or c-Si/SiOx/poly-Si (n+)]. Our focus is on the effects of the substrate preparation conditions (either by a dry-plasma or wet SiOx process) and the high-temperature annealing step (as required for the poly-Si crystallization) on the SiOx stoichiometry and its microscopic structure. Through advanced photoemission techniques, we find a clearly decreased valence band offset between the c-Si and SiOx (from 4.5 eV to 4.15 eV) when comparing the dry SiOx with the wet SiOx process, independent of the SiOx film thickness, but correlating with the relative fraction of sub-stochiometric Si states. We lastly examine the magnitude of band-bending of the contact structure through controlled in-situ exposure to light of the surfaces and subsequent tracking of core and valence band levels via a surface photovoltage and a junction photo-voltage (JPV) effect. By analyzing this JPV effect qualitatively, we find it to be proportional to the expected quasi fermi level splitting within the c-Si wafer.

'None of Them Know Me': A Qualitative Study of the Implications of Locum Doctor Working for Patient Experience.

INTRODUCTION: There have been some concerns about the impact of temporary doctors, otherwise known as locums, on patient safety and the quality of care. Despite these concerns, research has paid little attention to the implications of locum working on patient experience. METHODS: A qualitative semi-structured interview study was conducted with 130 participants including locums, people working with locums and patients with experience of being seen or treated by locums. Analysis was conducted using a reflexive thematic approach and abductive analysis to position themes against wider knowledge. RESULTS: Three main themes were constructed through analysis: (1) Awareness and disclosure; patients were not always aware if their doctor was a locum, and there was some debate about whether patients had a right to know, particularly if locum working presented quality and safety risks. (2) Continuity and accessibility of care; access was regarded as priority for acute conditions, but for long-term or serious conditions, patients preferred to see a permanent doctor who knew their history, although it was acknowledged that locums could provide fresh perspectives. (3) Communication and practice; locums and patients described how consultations were approached differently when doctors worked as locums. Patients evaluated their interactions based on how safe they felt with practitioners. CONCLUSION: Patients reported that they were unlikely to have continuity of care with any doctors delivering care, regardless of their contractual status. Locums sometimes provided new perspectives on care which could be beneficial for patient outcomes, but for patients with long-term, complex or serious conditions continuity of care was important, and these patients may avoid or delay seeking care when locums are the only available option. PATIENT OR PUBLIC CONTRIBUTION: Patients and carers were involved in our study from inception to dissemination. Our Patient and Public Involvement (PPI) forum was involved throughout project design and planning and gave us feedback and guidance on research materials and outputs (e.g., study protocol, participant information sheets, survey tools, interview schedules, emerging findings). Our PPI forum co-produced our patient interview schedule, two members of our PPI forum led the patient focus groups and all were involved in analysis of patient interviews. Our PPI Chair was involved in the preparation of this manuscript.

Association between regulator inspection and ratings on primary care prescribing: an observational study in England 2014 to 2019.

BACKGROUND: Healthcare regulators in many countries undertake inspections of healthcare providers and publish inspection outcomes with the intention of improving quality of care. Comprehensive inspections of general practices in England by the Care Quality Commission began for the first time in 2014. It is assumed that inspection and rating will raise standards and improve care, but the presence and extent of any improvements is unknown. We aim to determine if practice inspection ratings are associated with past performance on prescribing indicators and if prescribing behaviour changes following inspection. METHODS: Longitudinal study using a dataset of 6771 general practices in England. Practice inspection date and score was linked with monthly practice-level data on prescribing indicators relating to antibiotics, hypnotics and non-steroidal anti-inflammatory drugs. The sample covers practices receiving their first inspection between September 2014 and December 2018. Regression analysis and the differential timing of inspections is used to identify the impact on prescribing. RESULTS: Better-rated practices had better prescribing in the period before inspections began. In the six months following inspections, no overall change in prescribing was observed. However, the differences between the best and worse rated practices were reduced but not fully. The same is also true when taking a longer-term view. There is little evidence that practices responded in anticipation of inspection or reacted differently once the ratings were made public. CONCLUSION: While some of the observed historic variation in prescribing behaviour has been lessened by the process of inspection and ratings, we find this change is small and appears to come from both improvements among lower-rated practices and deteriorations among higher-rated practices. While inspection and rating no doubt had other impacts, these prescribing indicators were largely unchanged.

Sign language delays in deaf 3- to 5-year-olds with hearing parents.

Deaf children of hearing parents (DOH) are at risk for early language delays (ELD) due to environmental and etiological factors, compounding the previously reported higher incidence of ELD in deaf children of deaf parents (DOD) compared to the general population. Archival data from the online database of the Visual Communication and Sign Language Checklist yielded 147 ratings of DOH 3- to 5-year-old children whose parents reported American sign language (ASL) being used in the home at least equally to spoken language. Research goals included (1) examining the incidence of ELD in this cohort, (2) investigating differences in outcomes based on the scaling method used, (3) exploring patterns among the ratings of DOH children identified with ELD, (4) comparing the DOH outcomes to published DOD data, and (5) investigating differences between ratings and individual children. The DOH outcomes suggested an incidence of ELD twice that of the previous DOD sample, with a higher percentage of more severe delays. Even DOH children not identified with ELD demonstrated less well-developed ASL skills than their DOD peers. This emphasizes the need for ongoing monitoring of early ASL skills to allow for early identification of needs and adjustment of interventions to address ASL development.

Sign language delays in deaf 3- to 5-year-olds with deaf parents.

Research has demonstrated that deaf children of deaf signing parents (DOD) are afforded developmental advantages. This can be misconstrued as indicating that no DOD children exhibit early language delays (ELDs) because of their early access to a visual language. Little research has studied this presumption. In this study, we examine 174 ratings of DOD 3- to 5-year-old children, for whom signing in the home was indicated, using archival data from the online database of the Visual Communication and Sign Language Checklist. Our goals were to (1) examine the incidence of ELDs in a cohort of DOD children; (2) compare alternative scaling strategies for identifying ELD children; (3) explore patterns among behavioral ratings with a view toward developing a greater understanding of the types of language behaviors that may lie at the root of language delays; and (4) suggest recommendations for parents and professionals working with language-delayed DOD children. The results indicated that a significant number of ratings suggested ELDs, with a subset significantly delayed. These children likely require further evaluation. Among the less delayed group, ASL skills, rather than communication or cognition, were seen as the major concern, suggesting that even DOD children may require support developing linguistically accurate ASL. Overall, these findings support the need for early and ongoing evaluation of visual language skills in young DOD children.

Accumulation and ordering of P3HT oligomers at the liquid-vapor interface with implications for thin-film morphology.

The morphology of semiconducting polymer thin films is known to have a profound effect on their opto-electronic properties. Although considerable efforts have been made to control and understand the processes which influence the structures of these systems, it remains largely unclear what physical factors determine the arrangement of polymer chains in spin-cast films. Here, we investigate the role that the liquid-vapor interfaces in chlorobenzene solutions of poly(3-hexylthiophene) [P3HT] play in the conformational geometries adopted by the polymers. Using all-atom molecular dynamics (MD), and supported by toy-model simulations, we demonstrate that, with increasing concentration, P3HT oligomers in solution exhibit a strong propensity for the liquid-vapor interface. Due to the differential solubility of the backbone and side chains of the oligomers, in the vicinity of this interface, hexyl chains and the thiophene rings, have a clear orientational preference with respect to the liquid surface. At high concentrations, we additionally establish a substantial degree of inter-oligomer alignment and thiophene ring stacking near the interface. Our results broadly concur with the limited existing experimental evidence and we suggest that the interfacial structure can act as a template for film structure. We argue that the differences in solvent affinity of the side chain and backbone moieties are the driving force for the anisotropic orientations of the polymers near the interface. This finer grained description contrasts with the usual monolithic characterization of polymer units. Since this phenomenon can be controlled by concurrent chemical design and the choice of solvents, this work establishes a fabrication principle which may be useful to develop more highly functional polymer films.

The use of locum doctors in the NHS - results of a national survey of NHS Trusts in England.

BACKGROUND: Locum working in healthcare organisations has benefits for individual doctors and organisations but there are concerns about the impact of locum working on continuity of care, patient safety, team function and cost. We conducted a national survey of NHS Trusts in England to explore locum work, and better understand why and where locum doctors were needed; how locum doctors were engaged, supported, perceived and managed; and any changes being made in the way locums are used. METHODS: An online survey was sent to 191 NHS Trusts and 98 were returned (51%) including 66 (67%) acute hospitals, 26 (27%) mental health and six (6%) community health providers. Data was analysed using frequency tables, t-tests and correlations. Free-text responses were analysed using thematic analysis. RESULTS: Most NHS Trusts use locums frequently and for varying lengths of time. Trusts prefer to use locums from internal locum banks but frequently rely on locum agencies. The benefits of using locums included maintaining workforce capacity and flexibility. Importantly, care provided by locums was generally viewed as the same or somewhat worse when compared to care provided by permanent doctors. The main disadvantages of using locum agencies included cost, lack of familiarity and impact on organisational development. Some respondents felt that locums could be unreliable and less likely to be invested in quality improvement. NHS Trusts were broadly unfamiliar with the national guidance from NHS England for supporting locums and there was a focus on processes like compliance checks and induction, with less focus on providing feedback and support for appraisal. CONCLUSIONS: Locum doctors provide a necessary service within NHS Trusts to maintain workforce capacity and provide patient care. There are potential issues related to the way that locums are perceived, utilised, and supported which might impact the quality of the care that they provide. Future research should consider the arrangements for locum working and the performance of locums and permanent doctors, investigating the organisation of locums in order to achieve safe and high-quality care for patients.

Predicting optical spectra for optoelectronic polymers using coarse-grained models and recurrent neural networks.

Coarse-grained modeling of conjugated polymers has become an increasingly popular route to investigate the physics of organic optoelectronic materials. While ultraviolet (UV)-vis spectroscopy remains one of the key experimental methods for the interrogation of these materials, a rigorous bridge between simulated coarse-grained structures and spectroscopy has not been established. Here, we address this challenge by developing a method that can predict spectra of conjugated polymers directly from coarse-grained representations while avoiding repetitive procedures such as ad hoc back-mapping from coarse-grained to atomistic representations followed by spectral computation using quantum chemistry. Our approach is based on a generative deep-learning model: the long-short-term memory recurrent neural network (LSTM-RNN). The latter is suggested by the apparent similarity between natural languages and the mathematical structure of perturbative expansions of, in our case, excited-state energies perturbed by conformational fluctuations. We also use this model to explore the level of sensitivity of spectra to the coarse-grained representation back-mapping protocol. Our approach presents a tool uniquely suited for improving postsimulation analysis protocols, as well as, potentially, for including spectral data as input in the refinement of coarse-grained potentials.

The effect of source backing materials and excitation pulse durations on laser-generated ultrasound waveforms.

In this article, it is shown experimentally that a planar laser-generated ultrasound source with a hard reflective backing will generate higher acoustic pressures than a comparable source with an acoustically matched backing when the stress confinement condition is not met. Furthermore, while the source with an acoustically matched backing will have a broader bandwidth when the laser pulse is short enough to ensure stress confinement, the bandwidths of both source types will converge as the laser pulse duration increases beyond stress confinement. The explanation of the results is supported by numerical simulations.

Scaling-up a pharmacist-led information technology intervention (PINCER) to reduce hazardous prescribing in general practices: Multiple interrupted time series study.

BACKGROUND: We previously reported on a randomised trial demonstrating the effectiveness and cost-effectiveness of a pharmacist-led information technology intervention (PINCER). We sought to investigate whether PINCER was effective in reducing hazardous prescribing when rolled out at scale in UK general practices. METHODS AND FINDINGS: We used a multiple interrupted time series design whereby successive groups of general practices received the PINCER intervention between September 2015 and April 2017. We used 11 prescribing safety indicators to identify potentially hazardous prescribing and collected data over a maximum of 16 quarterly time periods. The primary outcome was a composite of all the indicators; a composite for indicators associated with gastrointestinal (GI) bleeding was also reported, along with 11 individual indicators of hazardous prescribing. Data were analysed using logistic mixed models for the quarterly event numbers with the appropriate denominator, and calendar time included as a covariate. PINCER was implemented in 370 (94.1%) of 393 general practices covering a population of almost 3 million patients in the East Midlands region of England; data were successfully extracted from 343 (92.7%) of these practices. For the primary composite outcome, the PINCER intervention was associated with a decrease in the rate of hazardous prescribing of 16.7% (adjusted odds ratio (aOR) 0.83, 95% confidence interval (CI) 0.80 to 0.86) at 6 months and 15.3% (aOR 0.85, 95% CI 0.80 to 0.90) at 12 months postintervention. The unadjusted rate of hazardous prescribing reduced from 26.4% (22,503 patients in the numerator/853,631 patients in the denominator) to 20.1% (11,901 patients in the numerator/591,364 patients in the denominator) at 6 months and 19.1% (3,868 patients in the numerator/201,992 patients in the denominator). The greatest reduction in hazardous prescribing associated with the intervention was observed for the indicators associated with GI bleeding; for the GI composite indicator, there was a decrease of 23.9% at both 6 months (aOR 0.76, 95% CI 0.73 to 0.80) and 12 months (aOR 0.76, 95% CI 0.70 to 0.82) postintervention. The unadjusted rate of hazardous prescribing reduced from 31.4 (16,185 patients in the numerator/515,879 patients in the denominator) to 21.2% (7,607 patients in the numerator/358,349 patients in the denominator) at 6 months and 19.5% (2,369 patients in the numerator/121,534 patients in the denominator). We adjusted for calendar time and practice, but since this was an observational study, the findings may have been influenced by unknown confounding factors or behavioural changes unrelated to the PINCER intervention. Data were also not collected for all practices at 6 months and 12 months postintervention. CONCLUSIONS: The PINCER intervention, when rolled out at scale in routine clinical practice, was associated with a reduction in hazardous prescribing by 17% and 15% at 6 and 12 months postintervention. The greatest reductions in hazardous prescribing were for indicators associated with risk of GI bleeding. These findings support the wider national rollout of PINCER in England.

Participatory mapping to address neighborhood level data deficiencies for food security assessment in Southeastern Virginia, USA.

BACKGROUND: Food is not equitably available. Deficiencies and generalizations limit national datasets, food security assessments, and interventions. Additional neighborhood level studies are needed to develop a scalable and transferable process to complement national and internationally comparative data sets with timely, granular, nuanced data. Participatory geographic information systems (PGIS) offer a means to address these issues by digitizing local knowledge. METHODS: The objectives of this study were two-fold: (i) identify granular locations missing from food source and risk datasets and (ii) examine the relation between the spatial, socio-economic, and agency contributors to food security. Twenty-nine subject matter experts from three cities in Southeastern Virginia with backgrounds in food distribution, nutrition management, human services, and associated research engaged in a participatory mapping process. RESULTS: Results show that publicly available and other national datasets are not inclusive of non-traditional food sources or updated frequently enough to reflect changes associated with closures, expansion, or new programs. Almost 6 percent of food sources were missing from publicly available and national datasets. Food pantries, community gardens and fridges, farmers markets, child and adult care programs, and meals served in community centers and homeless shelters were not well represented. Over 24 km2 of participant identified need was outside United States Department of Agriculture low income, low access areas. Economic, physical, and social barriers to food security were interconnected with transportation limitations. Recommendations address an international call from development agencies, countries, and world regions for intervention methods that include systemic and generational issues with poverty, incorporate non-traditional spaces into food distribution systems, incentivize or regulate healthy food options in stores, improve educational opportunities, increase data sharing. CONCLUSIONS: Leveraging city and regional agency as appropriate to capitalize upon synergistic activities was seen as critical to achieve these goals, particularly for non-traditional partnership building. To address neighborhood scale food security needs in Southeastern Virginia, data collection and assessment should address both environment and utilization issues from consumer and producer perspectives including availability, proximity, accessibility, awareness, affordability, cooking capacity, and preference. The PGIS process utilized to facilitate information sharing about neighborhood level contributors to food insecurity and translate those contributors to intervention strategies through discussion with local subject matter experts and contextualization within larger scale food systems dynamics is transferable.

Deaf Children's Engagement with American Sign Language-English Bilingual Storybook Apps.

Design features of American Sign Language (ASL)-English bilingual storybook apps on the tablet computers, based on learning research, are intended to facilitate independent and interactive learning of English print literacy and of ASL skill among young learners. In 2013, the Science of Learning Center on Visual Language and Visual Learning introduced the first in a series of storybook apps for the iPad based on literacy and reading research. The current study, employing a sample of signing deaf children examined children's self-motivated engagement with the various design features presented in the earliest of the apps, The Baobab, and analyzed the relationships of engagement with ASL skill and age of first exposure to ASL, ASL narrative ability, and grade-appropriate English reading ability. Results indicated a robust level of engagement with the app, and a relationship between app pages specifically targeting reading and early exposure and skill levels in ASL. No evidence of relationships between narrative and vocabulary skills and app reading engagement was found. Topics for future research, and strategies for app improvement are discussed.

ASL Developmental Trends Among Deaf Children, Ages Birth to Five.

Language development is an important facet of early life. Deaf children may have exposure to various languages and communication modalities, including spoken and visual. Previous research has documented the rate of growth of English skills among young deaf children, but no studies have investigated the rate of ASL acquisition. The current paper examines young deaf children's acquisition of ASL skills, the rate of growth over time, and factors impacting levels and growth rates. Seventy-three children ages birth to 5 were rated three times using the Visual Communication and Sign Language Checklist and given a scaled score at each rating. An average monthly gain score was calculated for each participant. The presence of a deaf parent, use of ASL at home, use of cochlear implant(s), whether the child was born deaf, and age of initial diagnosis were analyzed for their impact on the level of ASL skill and rate of growth. Results indicated that the use of ASL in the home has a significant positive effect on deaf children's ASL skill level. Additionally, children with lower initial ratings showed higher rates of growth than those with higher initial ratings, especially among school-aged children. The paper discusses implications and directions for future studies.

Psychometric Characteristics of the Visual Communication and Sign Language Checklist.

Since its publication in 2013, the Visual Communication and Sign Language (VCSL) Checklist has been widely utilized to assess the development of early American Sign Language skills of deaf children from birth to age 5. However, little research has been published using the results of VCSL assessments. Notably, no psychometric analyses have been conducted to verify the validity of the VCSL in a population whose characteristics are different from those of the small sample of native signing children from whom the published norms were created. The current paper, using data from the online version of the VCSL (VCSL:O), addresses this shortcoming. Ratings of the 114 VCSL items from 562 evaluations were analyzed using a partial-credit Rasch model. Results indicate that the underlying skill across the age range comprises an adequate single dimension. Within the items' age groupings, however, the dimensionality is not so clear. Item ordering, as well as item fit, is explored in detail. In addition, the paper reports the benefits of using the resulting Rasch scale scores, which, unlike the published scoring strategy that focuses on basal and ceiling performance, makes use of the ratings of partial credit, or emerging, skills. Strategies for revising the VCSL are recommended.

Description of a Multi-faceted COVID-19 Pandemic Physician Workforce Plan at a Multi-site Academic Health System.

BACKGROUND: The evolving COVID-19 pandemic has and continues to present a threat to health system capacity. Rapidly expanding an existing acute care physician workforce is critical to pandemic response planning in large urban academic health systems. INTERVENTION: The Medical Emergency-Pandemic Operations Command (MEOC)-a multi-specialty team of physicians, operational leaders, and support staff within an academic Department of Medicine in Calgary, Canada-partnered with its provincial health system to rapidly develop a comprehensive, scalable pandemic physician workforce plan for non-ventilated inpatients with COVID-19 across multiple hospitals. The MEOC Pandemic Plan comprised seven components, each with unique structure and processes. METHODS: In this manuscript, we describe MEOC's Pandemic Plan that was designed and implemented from March to May 2020 and re-escalated in October 2020. We report on the plan's structure and process, early implementation outcomes, and unforeseen challenges. Data sources included MEOC documents, health system, public health, and physician engagement implementation data. KEY RESULTS: From March 5 to October 26, 2020, 427 patients were admitted to COVID-19 units in Calgary hospitals. In the initial implementation period (March-May 2020), MEOC communications reached over 2500 physicians, leading to 1446 physicians volunteering to provide care on COVID-19 units. Of these, 234 physicians signed up for hospital shifts, and 227 physicians received in-person personal protective equipment simulation training. Ninety-three physicians were deployed on COVID-19 units at four large acute care hospitals. The resurgence of cases in September 2020 has prompted re-escalation including re-activation of COVID-19 units. CONCLUSIONS: MEOC leveraged an academic health system partnership to rapidly design, implement, and refine a comprehensive, scalable COVID-19 acute care physician workforce plan whose components are readily applicable across jurisdictions or healthcare crises. This description may guide other institutions responding to COVID-19 and future health emergencies.

Is it safer at the beach? Spatial and temporal analyses of beachgoer behaviors during the COVID-19 pandemic.

Tourism localities worldwide continue to grapple with how best to sustain coastal visitation during the COVID-19 pandemic. Emerging epidemiological science illustrates the risk of disease transmission is lower outdoors than indoors, and exposure is likely lower in outdoor, coastal environments due to dispersion and dilution of respiratory droplets through regular air flow. That said, it remains unclear how beachgoer behavior affects the likelihood of disease transmission. During summer 2020, we analyzed publicly-available beachcam video data and collected unmanned aerial vehicle (UAV) imagery at the recreational beach oceanfront in Virginia Beach, U.S.A. Data were collected over 24 days, documenting tourists' and recreationists' behaviors related to the public health guidance from the U.S. Centers for Disease Control, Commonwealth of Virginia Department of Public Health and City of Virginia Beach. Specifically, using a sample test area of beach and adjoining boardwalk, we investigated diurnal patterns of beach and boardwalk use, the location and density of use, as well as the presence of face coverings (i.e., masks) on boardwalk users. Results from beachcam analyses indicate a curvilinear trend in beach use, peaking in the mid-afternoon, while boardwalk use remained consistent throughout the day. Beachcam observations were corroborated by UAV photography and spatial analysis, indicating concentrated use of the beach adjoining shoreline above high tide, with onethird of the landward adjacent upper beach vacant. Among boardwalk pedestrians, few (8.7%) were observed wearing facial coverings. These findings point to both indirect and direct strategies coastal managers can implement to communicate when, where, and how to reduce the potential for transmission while accessing beach amenities during the COVID-19 pandemic.

High pulse energy fibre laser as an excitation source for photoacoustic tomography.

A custom fibre laser designed as an excitation source for biomedical photoacoustic tomography has been developed. It is based on a custom-drawn large core diameter fibre (200 µm) that enables high pulse energies (∼10 mJ) to be achieved. The system can provide variable pulse durations (10 - 500 ns) and pulse repetition frequencies (100 Hz - 1 kHz), as well as arbitrary pulse bursts according to specific user defined sequences. The system is also compact and does not require external water cooling. This, along with the flexibility in the temporal characteristics of its output that it offers, will aid the translation of photoacoustic imaging to practical application in medicine and biology.

Do performance indicators predict regulator ratings of healthcare providers? Cross-sectional study of acute hospitals in England.

OBJECTIVE: To determine whether a large set of care performance indicators ('Intelligent Monitoring (IM)') can be used to predict the Care Quality Commission's (CQC) acute hospital trust provider ratings. DESIGN: The IM dataset and first-inspection ratings were used to build linear and ordered logistic regression models for the whole dataset (all trusts). This was repeated for subsets of the trusts, with these models then applied to predict the inspection ratings of the remaining trusts. SETTING: The United Kingdom Department of Health and Social Care's Care Quality Commission is the regulator for all health and social care services in England. We consider their first-inspection cycle of acute hospital trusts (2013-2016). PARTICIPANTS: All 156 English NHS acute hospital trusts. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Percentage of correct predictions and weighted kappa. RESULTS: Only 24% of the predicted overall ratings for the test sample were correct and the weighted kappa of 0.01 indicates very poor agreement between predicted and actual ratings. This lack of predictive power is also found for each of the rating domains. CONCLUSION: While hospital inspections draw on a much wider set of information, the poor power of performance indicators to predict subsequent inspection ratings may call into question the validity of indicators, ratings or both. We conclude that a number of changes to the way performance indicators are collected and used could improve their predictive value, and suggest that assessing predictive power should be undertaken prospectively when the sets of indicators are being designed and selected by regulators.