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This paper presents the design and characterization of a unit cell for dual-polarized liquid crystal (LC)-based reconfigurable intelligent surfaces (RIS), as well as an efficient, full-wave simulation methodology for the far-field beam-steering capabilities of large-scale LC-RIS. Within this framework, the unit cell relies on defected delay lines with a 4.6 μm thin LC layer aperture coupled to a patch antenna. This delay line architecture aims towards simultaneous optimization of loss, bandwidth and response time. Full-wave simulations of the unit cell in a periodic environment show an operating frequency between 26.5 and 29.5 GHz with wide angle radiation. Measurements of the unit cell in a 3 $\times$ 3 rectangular grid exhibit wideband impedance matching and overall good agreement with simulations. Furthermore, a simulation methodology is introduced that evaluates large-scale LC-RIS far-field beam-steering capabilities without requiring full-wave simulations of the entire structure, but just few unit cells. Within this scope, the LC-RIS achieves a maximum efficiency of 20.8% with a beam-steering range from −48° to +48°, despite the use of a lossy glass substrate and gold as a conductor. It exhibits a minimum bandwidth of 8.2% for an efficiency of at least 10% across all analyzed steering angles in E-Plane and H-Plane.
The aim of this paper is to review the latest evidence on food reformulation as a public health policy to improve our understanding of how different policy designs can drive reformulation and influence food system change. The focus is on three key nutrients of concern—trans fatty acids, salt and sugar.
In recent times, food reformulation has been categorised as either mandatory or voluntary, a distinction that can help assess policy effectiveness. However, this binary classification oversimplifies a far more complex landscape. Some policies—whether mandated by government or voluntarily suggested to industry—are explicitly intended to trigger reformulation. Others, by contrast, may have never been designed with the intention to encourage reformulation but have nonetheless prompted significant changes in product composition, intake and potential health outcomes.
Within what is commonly described as mandatory reformulation, for example, we find a broad mix of policy tools that operate very differently. Some, such as the UK’s Soft Drinks Industry Levy, were deliberately created to incentivise reformulation by applying financial pressure. Others, including front of pack nutrition labelling systems (particularly warning labels) and school food standards have encouraged reformulation only as a positive unintended consequence. These indirect drivers are not always evaluated for their impact on reformulation, which may lead to an incomplete understanding of their contribution to reducing intake nutrients of concern and health outcomes.
Nevertheless, emerging evidence suggests no single policy encourages reformulation alone, instead a combination of approaches are likely to drive it and contribute to meaningful and sustained food system change.
We consider the flow of a viscous fluid through a two-dimensional symmetric cross-slot geometry with sharp corners. The problem is analysed using the unified transform method in the complex plane, providing a quasi-analytical solution that can be used to compute all the physical quantities of interest. This study is a novel application of this method to a complicated geometry featuring multiple sharp corner singularities and multiple inlets and outlets. Our approach offers the advantage of resolving unbounded domains, as well as providing quantities of interest, such as the velocity and stress profiles, and the Couette pressure correction, from the solution of low-order linear systems. Our results agree well with the existing literature, which has largely used truncated bounded geometries with rounded or curved corners.
We study quasi-stationary distributions and quasi-limiting behaviour of Markov chains in general reducible state spaces with absorption. First, we consider state spaces that can be decomposed into two successive subsets (with communication possible in a single direction), differentiating between three situations, and characterize the exponential order of magnitude and the exact polynomial correction, called the polynomial convergence parameter, for the leading-order term of the semigroup for large time. Second, we consider general Markov chains with finitely or countably many communication classes by applying the first results iteratively over the communication classes of the chain. We conclude with an application of these results to the case of denumerable state spaces, where we prove existence for a quasi-stationary distribution without assuming irreducibility before absorption, but only aperiodicity, existence of a Lyapunov function, and existence of a point with almost surely finite return time.
To evaluate eligibility and participation in nutrition assistance programs (Supplemental Nutrition Assistance Program [SNAP] and Woman, Infants, and Children [WIC]) among transgender and gender diverse (TGD) adults in the United States (U.S.) and to capture their experiences when accessing food benefits.
Design:
This was a cross-sectional analysis of the U.S. Transgender Survey (USTS) dataset– the largest survey of TGD adults in the U.S. SNAP and WIC participation and experiences when visiting the public assistance office were reported using descriptive statistics; stratified analyses were conducted based on race using multivariate logistic regression modeling.
Setting:
The USTS was completed electronically in the United States.
Participants:
27,715 TGD adults.
Results:
Approximately 40.9% of the full sample were SNAP eligible, yet only 30.6% of those eligible were receiving the benefit; 0.45% of the sample reported receiving WIC. TGD adults avoided the public assistance office because they feared being mistreated (3.2%), were identified as transgender (46.2%), were denied equal treatment (6.5%), or were verbally harassed (5.2%). People of color were more likely to be denied equal treatment and verbally harassed at the public benefits office than white peers. The impact of age, education level, employment status, relationship status, and census region varied within each racial group.
Conclusions:
Far more TGD adults need food assistance compared to the general population, yet fewer are receiving the benefit. Culturally informed interventions are urgently needed to resolve the root causes of food insecurity, increase SNAP participation and address the negative experiences of TGD adults when accessing food benefits.
Aspects of the school food environment can influence food purchasing and consumption among adolescents, particularly those without access to a school meal program. Our objective was to describe and compare food vendors of junior high schools in Ghana.
Design:
We conducted structured observations of food vendors within a 0.25-km radius of 8 junior high schools. We compared foods sold and hygiene practices by vendor and community characteristics, such as on vs off campus location, urban vs rural, and predominant income generating activity of the community. We also assessed the relationship between adolescent diet quality (food group diversity, all-5, NCD-protect, and NCD-risk scores) and procurement method for foods consumed during the school day.
Setting:
Cape Coast and Elmina, Ghana
Participants:
200 randomly selected students.
Results:
Of 265 identified vendors, 25.3% sold foods on-campus. On-campus vendors were less likely to sell branded snacks (19.4% vs. 33.8%, p=0.001), and beverages (17.9% vs. 35.4%, p=0.008) and more likely to sell prepared dishes (53.7% vs. 31.8%, p=0.001) than off-campus vendors. Vendors practiced an average of 38.8% of applicable food hygiene practices, which did not differ by on- or off- campus location. In the previous month, 59.4% of students most often purchased food on campus. There were no significant relationships between method of food procurement and diet quality.
Conclusion:
Many adolescents purchased food at school and there were differences in foods sold by on- and off campus vendors. School policies may be a promising avenue to alter food environments for adolescents.
Pre-existing bubbles in the water play a critical role in influencing the impact pressure characteristics during the wedge water entry. This study experimentally and analytically investigates the effect of aeration on water-entry impact. A series of controlled drop tests were conducted using a wedge with a 20° deadrise angle at varying impact velocities and void fractions. Four classical pure water impact models (the Zhao & Faltinsen model (ZFM), original Logvinovich model (OLM), modified Logvinovich model (MLM) and generalised Wagner model (GWM)) were extended to account for the effect of aeration. These modifications accounted for compressibility effects, the time-dependent void fraction, three-dimensional flow corrections and area-averaged pressure calculations, resulting in four modified models (M-ZFM, M-OLM, M-MLM and M-GWM). This marks the first systematic theoretical extension of multiple classical water-entry models to aerated conditions. The proposed models demonstrated good agreement with experimental results, with the M-MLM providing accurate peak pressure predictions and M-GWM performing best in capturing the post-peak behaviours. The results indicated that the expansion velocity of the wetted surface varied spatially and closely matched the M-ZFM predictions. While the peak pressures decreased by up to 32.8 % in highly aerated water, the prolonged impact durations led to a comparable or slightly increased pressure impulse than that in pure water. This finding suggests that prolonged lower-magnitude impacts in aerated water may pose a greater risk to structural safety than short-duration high-magnitude impacts. These contributions offer new physical insight and validated tools relevant to marine engineering design in aerated environments.
We present a framework to calculate the scale-resolved turbulent Prandtl number ${\textit{Pr}}_t$ for the well-mixed and highly inertial bulk of a turbulent Rayleigh–Bénard mesoscale convection layer at a molecular Prandtl number of ${\textit{Pr}}=10^{-3}$. It builds on Kolmogorov’s refined similarity hypothesis of homogeneous isotropic fluid and passive scalar turbulence, based on log–normally distributed amplitudes of kinetic energy and scalar dissipation rates that are coarse-grained over variable scales $r$ in the inertial subrange. Our definitions of turbulent (or eddy) viscosity and diffusivity do not rely on mean gradient-based Boussinesq closures of Reynolds stresses and convective heat fluxes. Such gradients are practically absent or indefinite in the bulk. The present study is based on direct numerical simulation of plane-layer convection at an aspect ratio of $\varGamma =25$ for Rayleigh numbers $10^5\leqslant Ra\leqslant 10^7$. We find that the turbulent Prandtl number is effectively up to four orders of magnitude larger than the molecular one, ${\textit{Pr}}_t\sim 10$. This holds particularly for the upper end of the inertial subrange, where the eddy diffusivity exceeds the molecular value, $\kappa _e(r)\gt \kappa$. Highly inertial low-Prandtl-number convection becomes effectively a higher-Prandtl-number turbulent flow, when turbulent mixing processes on scales that reach into the inertial range are included. This might have some relevance for prominent low-Prandtl-number applications, such as solar convection.
This study documents and analyzes arthropod trackways from the Upper Cretaceous Wapiti Formation, located in west-central Alberta, Canada. In general, the ichnotaxonomy of arthropod trackways is problematic due to inconsistent use of diagnostic criteria in previous studies. Thus, the trackways from the Wapiti Formation are described following recently defined criteria to facilitate future ichnotaxonomic reevaluations. Judging primarily from the number and morphology of the imprints and the symmetry of the track series, the trackways are identified as Octopodichnus cf. O. raymondi Sadler, 1993. Other relevant track attributes include heteropody and great imprint depth. The mudstone slabs bearing the trackways also contain other well-preserved invertebrate trace fossils along with abundant silicified plant material. The silicified plant fragments, taken together with bentonite overlying the trace-bearing surface, suggest volcanic ash played a role in preserving the trackways. The associated traces include burrows, fecal mounds, and surficial marks and contribute to a diverse invertebrate trace-fossil assemblage. The Wapiti Formation trackways are attributed to crayfish or similar decapods and were emplaced in a succession interpreted to have been deposited in a swampy floodplain environment. By contrast, previously described examples of Octopodichnus have typically been attributed to arachnids in aeolian/desert environments. This paper expands the ichnological record of crayfish-like arthropods from the Late Cretaceous and contributes to the underexplored invertebrate fossil record of the Wapiti Formation and, more broadly, Cretaceous strata in the Western Canada Sedimentary Basin.
The present study examined the association of body mass index (BMI), screen and sleep time, physical fitness and eating behaviour with Mediterranean diet (MD) adherence in a sample of pre-schoolers from Granada, Spain.
Design:
A cross-sectional, non-randomised design was employed. A multilinear regression model with backward elimination was used for analysis.
Setting:
Variables included age, BMI, screen time, hours of nightly sleep, physical fitness, food approach and food avoidance. The developed model met assumptions of multiple regression in terms of linearity, homoscedasticity, normality, independence and non-multicollinearity.
Participants:
Data were collected from 653 of the 2250 three-to-six-year-old children attending the 18 schools invited to take part in the present study.
Results:
Better sleep time and lower screen time and food avoidance were found to be predictive of MD adherence. These variables explained 15% of the variance in pre-schoolers MD adherence.
Conclusions:
The present study suggests that sleep and screen time and food avoidance are important components to consider when targeting improvements in MD adherence in pre-schoolers. Future research should explore the way in which parental health behaviours influence their children’s health habits in order to better understand outcomes.
The role of healthcare provider ownership in shaping health system performance remains contested. An umbrella review was conducted to synthesise evidence on the relationship between healthcare provider ownership and performance in high-income countries. Systematic reviews were included that examined performance of healthcare providers based on ownership status. Searches yielded 1,862 results, with 31 systematic reviews meeting the inclusion criteria, and one further systematic review identified through grey literature searches. Following the exclusion of 10 reviews classified as low-quality and two previous umbrella reviews both published in 2014, 20 reviews were eligible for data extraction and synthesis. Inconsistent evidence was found across reviews between healthcare provider ownership and several performance indicators including health outcomes, technical efficiency, and patient satisfaction. Private hospitals tend to serve wealthier patients, select less complex or costly patients, and charge higher payments for care than public comparators. Private for-profit (FP) providers of hospital and long-term care generally had poorer workforce outcomes than private not-for-profit or public providers, including reduced staffing levels, higher workloads, and lower job satisfaction. Private PF hospitals and nursing homes had improved financial performance based on revenues or profit margins. Our findings underscore the need for nuanced regulatory responses to the expansion of private FP provision within publicly funded systems.
Governments across the world are leveraging artificial intelligence (AI) to render services to citizens. Emerging economies are not left behind in this transformation but remain a gaping distance behind in their integration into public-sector service delivery compared to the private sector. To ensure the effective integration of AI services by government agencies to serve citizens, it is necessary to understand the constellation of factors driving user adoption of AI. Therefore, this study answers the question: how can government-initiated AI services be successfully accepted by citizens? Leveraging non-probability sampling, a snowball sample of 245 tertiary student-workers from across Ghana was surveyed to solicit their knowledge, attitudes, readiness, and use intentions towards AI-enabled government services. The data were analysed using FsQCA and complemented by PLS-SEM to confirm the findings. The findings reveal four unique configurations, summarised into two broad groups; AI enthusiasts and AI sceptics that drive AI adoption in government services. Positive readiness factors, such as knowledge of AI and optimism towards AI, characterise AI enthusiasts. In contrast, those described as AI sceptics still adopt government AI services despite their reservations and general distrust. AI sceptics are a delicate group that sit at the boundary between adoption and rejection, requiring special attention and strategies to orient them towards adoption. The study recommends effective education and trust-building strategies to foster AI adoption in government services. The findings are essential for driving the efficient implementation of AI-enabled services among working-class citizens in emerging economies.
This study aims to examine the awareness, attitudes, and acceptability of medical aid in dying (MAiD) among healthcare professionals in Pakistan, a predominantly Muslim country where cultural and religious values heavily influence medical ethics and end-of-life decisions.
Methods
A cross-sectional survey was conducted online among 70 healthcare professionals, including physicians, nurses, and allied health workers in Pakistan. Data were collected via a structured, self-administered online questionnaire assessing knowledge, attitudes, and willingness to participate in MAiD-related actions. Descriptive and correlational analyses were conducted to identify patterns and associations.
Results
Participants demonstrated moderate knowledge about MAiD (M = 17.13, SD = 3.42) and moderate support for its legalization (M = 18.89, SD = 4.99). However, levels of negative attitudes (M = 32.21, SD = 6.11) and legal and ethical concerns (M = 24.73, SD = 3.66) were high. Behavioral willingness to engage in MAiD-related actions remained low (M = 2.42, SD = 3.38), with limited intent to assist (M = 0.39), refer (M = 0.64), or approve physician-assisted MAID (M = 0.81). A significant negative correlation emerged between knowledge and support for legalization (r = − .25, p = .037), while no significant associations were observed between knowledge and willingness to participate in MAiD. Gender and profession did not significantly influence attitudes or willingness.
Significance of results
While Pakistani healthcare professionals display a conceptual understanding of MAiD, their readiness to participate remains low, primarily due to ethical, legal, and religious concerns. These findings highlight the need for creating awareness regarding MAiD and for providing culturally sensitive education, structured training in palliative care, and the development of clear legal frameworks to guide end-of-life decision-making in Muslim-majority contexts.
Bypass transition, momentum and passive scalar transports in an initially laminar low Reynolds number channel flow with a specific roughness morphology are investigated by direct numerical simulations. The roughness elements are square bars of large heights $k$. Turbulence cannot be triggered in an initially laminar flow without external noise, when the bars extend the entire width of the channel. A staggered configuration is necessary to break up the spanwise symmetry, in which case a pseudo-fully developed rough regime sets up and self-sustains near and below the subcritical Reynolds number. The critical parameter is the shift $s$ between two consecutive staggered bars spanning half the width of the channel. A small shift $s/k$ is enough to trigger the turbulent field. Momentum and scalar fields are analysed for different $s/k$ configurations. The Townsend similarity hypothesis postulating that the outer layer is insensitive to the roughness effects, and that the rough- and smooth-wall statistics collapse in the outer layer, holds well for the momentum field despite the large roughness heights. A particular attention is paid to the deviation of the scalar statistics from the Townsend hypothesis. There is a dissimilarity between the fluctuating temperature and the velocity fields. The Reynolds analogy does not hold stricto sensu. Wake-induced terms determined through the double-averaging procedure play an important role in the rough sublayer. For instance, a significative production of the fluctuating spanwise velocity intensity, which is absent in the canonical flow, appears as a wake-induced term at small shifts. This is solely due to the imposed spanwise asymmetry. The nature, the generation and the self-sustaining mechanisms of the coherent structures near and between the roughness elements are analysed in detail in different configurations. There is a substantial increase of the Nusselt number at particularly low Reynolds numbers.
To explore the experiences of military medical first responders managing mass casualty incidents (MCIs) during the ongoing conflict in Ukraine to identify key challenges and insights.
Methods
This qualitative study employed in-depth, semi-structured interviews with medical first responders who managed MCIs in Ukraine. Thematic analysis was leveraged by our research team to identify recurring themes and patterns within the interview data.
Results
Our results revealed crucial takeaways related to the (1) need for preparedness and training, (2) variability of triage, (3) importance of communication and teamwork, and (4) the resulting psychological strain.
Conclusions
These firsthand accounts offer valuable lessons for identifying challenges of first responders, developing areas of future research for MCI response strategies, and enhancing the readiness and well-being of medical first responders in current and future conflicts.
This study assessed iron-rich food consumption and its factors among children aged 6–23 months in South and Southeast Asia.
Design:
A cross-sectional study from the Standard Demographic and Health Survey (2015-2022).
Setting:
South and Southeast Asian countries.
Subjects:
Data collected from 95,515 children aged 6 to 23 months, including information from their parents or caregivers.
Results:
The overall proportion of children, aged 6 to 23 months, consuming iron-rich foods in the region was 29.87% (95% CI: 29.58, 30.16). Higher odds of iron-rich food consumption were observed among children aged 12–23 months (AOR = 3.59; 95% CI: 3.45–3.76), had history of exclusive breastfeeding (AOR = 1.17; 95% CI: 1.12–1.23), born to teenage motherhood (AOR = 1.09; 95% CI: 1.02–1.17), born in health institution (AOR = 1.10; 95% CI: 1.02–1.19), and had pregnant mother at the time of the survey (AOR = 1.60; 95% CI: 1.50–1.72). Children of birth order 2–4 (AOR = 1.26; 95% CI: 1.20–1.32) and 5+ (AOR = 1.29; 95% CI: 1.18–1.43), from female-headed households (AOR = 1.06; 95% CI: 1.01–1.12), and those with household mass media exposure (AOR = 1.27; 95% CI: 1.19–1.36) also had significantly higher odds of iron-rich food consumption. Additionally, higher odds ratios (AOR > 1) of iron-rich food consumption were observed in Cambodia, Bangladesh, Indonesia, Myanmar, Maldives, Philippines, Pakistan, and Timor-Leste.
Conclusion:
Across countries, only about 30% of children consumed iron-rich foods, with significant variation. Targeted public health efforts are essential to address maternal, child, and household factors that influence intake.
Patients with chronic liver disease (CLD) often experience hypozincemia. The clinical factors associated with hypozincemia have not been established. We investigated clinical factors that may be useful to predict hypozincemia in patients with CLD. The serum zinc levels CLD patients were measured; Study 1 investigated the predictive factors of hypozincemia, and Study 2 was performed to validate the factors identified in Study 1. Study 1 included 197 participants, of whom 28 and 106 had serum zinc levels <60 µg/dL and <80 µg/dL, respectively. A multivariate analysis revealed that serum zinc levels <60 µg/dL or <80 µg/dL were associated with the albumin–bilirubin (ALBI) score and serum albumin level. A receiver operating characteristic curve analysis revealed that the ALBI score ≥ −1.83 and the serum albumin level ≤3.3 g/dL were the cut-off values for a serum zinc level <60 µg/dL, whereas the ALBI score ≥ −2.44 and the serum albumin level ≤3.6 g/dL were the cut-off values for a serum zinc level <80 µg/dL. In Study 2 (n = 177), the diagnostic accuracy rates for serum zinc <60 µg/dL were 81.9% for the ALBI score and 75.1% for the serum albumin level, and those for serum zinc <80 µg/dL were 70.1% for both parameters. Together these findings indicate that the ALBI score may serve as a predictive factor of hypozincemia in CLD patients.