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We investigated the dynamics of thin-layer formation by non-spherical motile phytoplankton in time-dependent shear flow, building on the seminal work of Durham et al. (2009 Science vol. 323, pp. 1067–1070), on spherical microswimmers in time-independent flows. By solving the torque balance equation for a microswimmer, we found that the system is highly damped for body sizes smaller than $10^{-3}$ m, with initial rotational motion dissipating quickly. From this torque balance, we also derived the critical shear for ellipsoidal microswimmers, which we validated numerically. Simulations revealed that the peak density of microswimmers is slightly higher than the theoretical prediction due to the speed asymmetry of sinking and gyrotaxis above and below the predicted height. In addition, we observed that microswimmers with higher aspect ratios tend to form thicker layers due to slower angular velocity. Using linear stability analysis, we identified a thin-layer accumulation time scale, which contains two regimes. This theoretically predicted accumulation time scale was validated through simulations. In time-dependent flow with oscillating critical shear depth, we identified three accumulation regimes and a transitional regime based on the ratio of swimmer and flow time scales. Our results indicate that thin layers can form across time scale ratios spanning five orders of magnitude, which helps explain the widespread occurrence of thin phytoplankton layers in natural water bodies.
This investigation evaluates the relationships between claims of patient and health system benefit, evidence in support of those claims, and the recommendation outcomes of medical technologies assessed by the National Institute for Health and Care Excellence (NICE).
Methodology
Data on evidence, claims, and recommendation outcomes were gathered from published Medical Technologies Guidances (MTGs) on the NICE Web site between 1 December 2010 and 11 April 2023. Binary logistic regressions and descriptive data analyses were performed to investigate the correlation between claims, evidence, and recommendation outcomes.
Results
The technology was fully or partially recommended in forty-six (67.7 percent) of sixty-eight MTGs. No correlation was found between types and number of claims and type and quantity of clinical evidence. However, claims supported directly by evidence were significantly correlated (p < 0.016) with recommendation.
Conclusion
Evidence supporting claims is crucial for receiving a full or partial guidance recommendation. There is no clear pattern in what kind of or quantity of evidence leads to a recommendation, and to increase the probability of receiving a favorable recommendation, the manufacturer needs to plan early in the development phases on how to articulate and refine the claims and to substantiate claims through clinical evidence. It is therefore advisable to take advantage of the opportunity for scientific advice, which NICE offers.
The effects of surface roughness in the transitionally rough regime on the overlying near-wall turbulence are modelled using quasi-linear approximations proposed recently: minimal quasi-linear approximation (MQLA) (Hwang & Ekchardt, 2020, J. Fluid Mech., vol. 894, A23), data-driven quasi-linear approximation (DQLA) (Holford et al., 2024, J. Fluid Mech., vol. 980, A12) and a newly established variant of MQLA (M2QLA, minimal two-mode quasi-linear approximation). The transpiration-resistance model (TRM) for boundary conditions is applied to account for the surface roughness (Lācis et al., 2020, J. Fluid Mech., vol. 884, A21). It is shown that many essential near-wall turbulence statistics are fairly well captured by the quasi-linear approximations in a wide range of slip and transpiration lengths for the TRM boundary conditions. In particular, the virtual origins and the resulting roughness functions are well predicted, showing good agreement with those from previous direct numerical simulations (DNS) in mild roughness cases. The DQLA and M2QLA, which incorporate streamwise-dependent Fourier modes in the approximations, are also shown to perform a little better than MQLA, especially with DQLA reproducing the two-dimensional energy spectra qualitatively consistent with the DNS. Finally, with a computational cost much lower than DNS, it is shown that the proposed quasi-linear approximation frameworks offer an efficient tool to rapidly explore the roughness effects within a large parameter space.
About one-third of South African women have clinically significant symptoms of postpartum depression (PPD). Several socio-demographic risk factors for PPD exist, but data on medical and obstetric risk factors remain scarce for low- and middle-income countries and particularly in sub-Saharan Africa. We aimed to estimate the proportion of women with PPD and investigate socio-demographic, medical and obstetric risk factors for PPD among women receiving private medical care in South Africa (SA).
Methods
In this longitudinal cohort study, we analysed reimbursement claims from beneficiaries of an SA medical insurance scheme who delivered a child between 2011 and 2020. PPD was defined as a new International Classification of Diseases, 10th Revision diagnosis of depression within 365 days postpartum. We estimated the frequency of women with a diagnosis of PPD. We explored several medical and obstetric risk factors for PPD, including pre-existing conditions, such as HIV and polycystic ovary syndrome, and conditions diagnosed during pregnancy and labour, such as gestational diabetes, pre-term delivery and postpartum haemorrhage. Using a multivariable modified Poisson model, we estimated adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) for factors associated with PPD.
Results
Of the 47,697 participants, 2,380 (5.0%) were diagnosed with PPD. The cumulative incidence of PPD increased from 0.8% (95% CI 0.7–0.9) at 6 weeks to 5.5% (5.3–5.7) at 12 months postpartum. PPD risk was higher in individuals with history of depression (aRR 3.47, 95% CI [3.14–3.85]), preterm delivery (1.47 [1.30–1.66]), PCOS (1.37 [1.09–1.72]), hyperemesis gravidarum (1.32 [1.11–1.57]), gestational hypertension (1.30 [1.03–1.66]) and postpartum haemorrhage (1.29 [0.91–1.85]). Endometriosis, HIV, gestational diabetes, foetal stress, perineal laceration, elective or emergency C-section and preeclampsia were not associated with a higher risk of PPD.
Conclusions
The PPD diagnosis rate was lower than anticipated, based on the PPD prevalence of previous studies, indicating a potential diagnostic gap in SA’s private sector. Identified risk factors could inform targeted PPD screening strategies.
We introduce a notion of equivariant vector bundles on schemes over semirings. We do this by considering the functor of points of a locally free sheaf. We prove that every toric vector bundle on a toric scheme X over an idempotent semifield equivariantly splits as a sum of toric line bundles. We then study the equivariant Picard group $\operatorname{Pic}_G(X)$. Finally, we prove a version of Klyachko’s classification theorem for toric vector bundles over an idempotent semifield.
We numerically investigate the fluid dynamics of the infusion of balanced salt solution into the vitreous chamber during ophthalmic surgery. A 25-gauge vitrectomy set consisting of an infusion cannula and a vitreous cutter is inserted in a realistic model of a human vitreous chamber. As the vitreous cutter aspirates at a constant flow rate (7.5–20 ml min−1 in the present study), the corresponding infusion flow generates a high-velocity laminar jet (1.00–2.65 m s−1) causing high stress on the retina (pressure up to 1200 Pa) and mixing. We analyse the Lagrangian coherent structures and quantify mixing. Results show a vortex ring around the jet impingement region, in the posterior part of the chamber. At higher infusion rates (Re > 600), interacting hairpin vortices emerge as a result of an instability in the vortex ring. This disordered flow enhances mixing, potentially dispersing substances such as vital dyes, with consequences on visibility and surgery time. We quantify the overall mixing and its evolution with height, observing a smooth transition from an ordered flow to an unsteady disordered one with the flow rate. These findings may pave the way towards strategies to minimise complications while optimising efficiency, especially given the trend towards minimally invasive surgery with progressively smaller infusion cannulas.
Sharp, nonasymptotic bounds are obtained for the relative entropy between the distributions of sampling with and without replacement from an urn with balls of $c\geq 2$ colors. Our bounds are asymptotically tight in certain regimes and, unlike previous results, they depend on the number of balls of each color in the urn. The connection of these results with finite de Finetti-style theorems is explored, and it is observed that a sampling bound due to Stam (1978) combined with the convexity of relative entropy yield a new finite de Finetti bound in relative entropy, which achieves the optimal asymptotic convergence rate.
Is it ever rational to change your mind based on learning that others have changed theirs? This paper answers affirmatively and explores the conditions under which learning about others’ mind-changes should prompt you to reconsider your own. I propose that learning about others’ shifts in belief can motivate further inquiry, provide information about the existence or quality of first-order evidence, and recalibrate our evaluation of the issues at stake. However, not all changes of mind are epistemically meaningful: some may be superficial, misleading, or driven by non-epistemic factors. Critical evaluation is necessary for distinguishing between cases that provide genuine insight and those that are irrelevant. By investigating these dynamics, I aim to illuminate the broader epistemological significance of mind-changing and its implications for navigating complex and contentious issues.
Social disconnection, covering loneliness and social isolation, might be associated with the development of paranoid thoughts. Differential effects of loneliness and social isolation on the occurrence of paranoia have not been tested so far. Moreover, the role of cognitive mechanisms in these associations remains unknown. This study aimed to investigate differential associations of loneliness and social isolation with paranoid thoughts in the general population, considering the role of cognitive mechanisms.
Methods
Altogether, 3,275 individuals, enrolled from the general population, completed baseline and follow-up assessments spanning 6–7 months. Cognitive biases (rejection sensitivity, attributional biases, and safety behaviors), social cognitive problems, and subjective cognitive problems were measured. The cross-lagged panel network (CLPN) analysis was performed, controlling for the effects of sociodemographic characteristics, psychiatric treatment, substance use, depressive, and anxiety symptoms. Additionally, mediation was tested for the CLPN paths linking social disconnection with paranoid ideation, with one intermediary node representing cognitive processes.
Results
Loneliness was the most important node in terms of predicting other network variables. It was bidirectionally associated with paranoid thoughts. Cognitive processes mediated these associations (partial mediation for ideas of reference and full mediation for ideas of persecution). In turn, social isolation predicted paranoid thoughts through the effects on loneliness. It was also predicted by paranoid thoughts through attributional biases.
Conclusions
Social disconnection might be bidirectionally associated with paranoid thoughts. However, loneliness is more closely tied to paranoid thoughts compared to social isolation. Cognitive processes might mediate the association of social disconnection with paranoid thoughts.
The concept of hedging has been recently introduced and has been gaining traction in International Relations (IR) literature. So far, the notion has been mainly employed to make sense of the strategic behaviour of some south-east Asian secondary states amid growing Sino-American great power competition. Hedging can be understood as a strategy through which a minor state avoids clearly aligning vis-à-vis two powerful vying actors, maintaining instead an in-between and balanced position. As such, hedging can be interpreted as a peculiar form of neutrality. Yet such a paralleling has not been spelled out clearly from a theoretical standpoint in the existing literature. Moreover, no attempt has been made to precisely position hedging among the different categories of neutrality. This is a major gap, as it deprives the hedging concept of much of its theoretical and analytical usefulness in informing scholarly analyses. By precisely locating hedging within the neutrality family and by identifying its main analytical features, this paper aims to clarify theoretically the ‘nature’ of the phenomenon. At the same time, such operation aims to move the hedging literature beyond its current overwhelming focus on contemporary south-east Asia, opening up interesting empirical perspectives for the study of hedging across time.
Intestinal health challenges – including dysbiosis, inflammatory disorders, and pathogen susceptibility – impose severe economic losses and welfare concerns in intensive livestock production. Functional lipids, defined as bioactive lipid molecules with physiological benefits beyond basic nutrition, offer promising solutions to these issues. This review establishes a comprehensive definition of functional lipids and elucidates their metabolic process. Using short- and medium-chain fatty acid glycerides as a prime example, we examine their significant roles in energy homeostasis, gut microbiota composition and diversity, immune modulation, and antibacterial and antiviral activities. Additionally, we critically evaluate their current applications and future industrial potential in livestock production, providing evidence-based recommendations for their optimal implementation in animal nutrition strategies.
The COVID-19 pandemic brought the EU health mandate under unprecedented scrutiny, providing a new impetus for action. The European Commission launched the ‘European Health Union’ (EHU), bringing a number of pre-existing and newer policy initiatives under a common umbrella. This contribution looks back at the recent developments in EU health law and policy, taking the 2019–2024 parliamentary term as a boundary. It offers an overview of what the EHU currently is, and what it could become. Despite its potential, the EHU is not yet a game changer. This can only happen if changes are brought to the EU’s competence and budgetary frameworks. The contribution provides first a brief introduction to the EU’s complex health competence framework and its general policy orientations in the field. We turn next to COVID-19, offering a condensed overview of the EU’s response and of the subsequent changes brought to the legal framework applicable to health emergencies. We finish by casting a closer look at the EHU, examining the descriptive and normative aspects of this concept, and making recommendations to increase the clarity, quality and legitimacy of EU action in the field.
The ageing population is anticipated to encounter several challenges related to sustainability. While policies such as ageing in place can benefit older adults in terms of familiarity and independence, these policies can also lead to increased social isolation. To facilitate ageing in the right place, it is crucial to understand how the design of environments promotes social sustainability. This article presents a scoping review of empirical research focused on the characteristics of housing and surrounding environments that support social integration, cohesion and participation of older adults. The search strategy was conducted in five databases, resulting in 20,477 articles. After screening 7,550 titles and abstracts based on predetermined inclusion and exclusion criteria, 19 articles were selected. The findings of these articles are presented across three themes: (1) housing environments, (2) environments beyond the home and (3) the social environment. Although there is no one-size-fits-all housing model for older adults, the authors suggest that ageing in place policies should be reconceptualized as ageing in ‘places’ and ‘spaces’, emphasizing the diversity of social needs of older adults. Understanding the environmental characteristics, the role of accessible and safe environments beyond the home, and how people and culture support a sense of belonging provides a policy direction for how to design socially sustainable environments for older adults in the future.
The adoption of the main text of the Pandemic Agreement at the 2025 World Health Assembly is a milestone in global health law. The adopted text makes several key contributions, but there were several missed opportunities in the negotiating process, and key roadblocks remain for the future of the Pandemic Agreement.
This paper examines the legal implications of the explicit mentioning of automation bias (AB) in the Artificial Intelligence Act (AIA). The AIA mandates human oversight for high-risk AI systems and requires providers to enable awareness of AB, i.e., the human tendency to over-rely on AI outputs. The paper analyses the embedding of this extra-juridical concept in the AIA, the asymmetric division of responsibility between AI providers and deployers for mitigating AB, and the challenges of legally enforcing this novel awareness requirement. The analysis shows that the AIA’s focus on providers does not adequately address design and context as causes of AB, and questions whether the AIA should directly regulate the risk of AB rather than just mandating awareness. As the AIA’s approach requires a balance between legal mandates and behavioural science, the paper proposes that harmonised standards should reference the state of research on AB and human-AI interaction, holding both providers and deployers accountable. Ultimately, further empirical research on human-AI interaction will be essential for effective safeguards.
The paper presents a simulation of the turbulent flow over and through a submerged aquatic canopy composed of 672 long, slender ribbons modelled as Cosserat rods. It is characterized by a bulk Reynolds number of 20 000, and a friction Reynolds number of 2638. Compared with a smooth turbulent channel at the same bulk Reynolds number, the canopy increases drag by a factor of 12. The ribbons are highly flexible, with a Cauchy number of 25 000, slightly buoyant, and densely packed. Their length exceeds the channel height by a factor of 1.6, while their average reconfigured height is only a quarter of the channel height. Different from lower-Cauchy-number cases, the movement of the ribbons, characterized by the motion of their tips, is very pronounced in the vertical direction, and even more in the spanwise direction, with root-mean-square fluctuations of the spanwise tip position 1.5 times the vertical ones. A canopy hull is defined to analyse the collective motion of the canopy and its interaction with the outer flow. Dominant spanwise wavelengths at this interface measure approximately one channel height, corresponding to twice the spacing of adjacent high- and low-speed streaks identified in two-point correlations of fluid velocity fluctuations. Conditional averages associated with troughs and ridges in the topography of the hull reveal streamwise-oriented counter-rotating vortices. They are reminiscent of the head-down structures related to the monami phenomenon in lower-Cauchy-number cases.
This study analyses the evolution of body mass index (BMI) as income increases across the population, controlling for age, sex, educational level, marital status and some lifestyle habits. To this end, a quantile regression, an econometric technique that readjusts the weights of the variables in each quantile to minimize deviations, has been carried out, where the variable that orders the sample is income. We use 316,777 observations from the European Health Interview Survey (EHIS) for these regressions. This approach allows us to separate the regression analyses for low-, middle-, and high-income groups, evidence that as individual income increases, BMI tends to rise. Consequently, individuals with higher incomes exhibit higher BMI levels. Additionally, the estimated parameters for explanatory variables increase with income, signifying that wealthier individuals not only have a greater likelihood of increased BMI but also that socio-economic factors influencing BMI – whether positively or negatively – evince a stronger impact as income levels rise.
Early language development has rarely been studied in hearing children with deaf parents who are exposed to both a spoken and a signed language (bimodal bilinguals). This study presents longitudinal data of early communication and vocabulary development in a group of 31 hearing infants exposed to British Sign Language (BSL) and spoken English, at 6 months, 15 months, 24 months and 7 years, in comparison with monolinguals (exposed to English) and unimodal bilinguals (exposed to two spoken languages). No differences were observed in early communication or vocabulary development between bimodal bilinguals and monolinguals, but greater early communicative skills in infancy were found in bimodal bilinguals compared to unimodal bilinguals. Within the bimodal bilingual group, BSL and English vocabulary sizes were positively related. These data provide a healthy picture of early language acquisition in those learning a spoken and signed language simultaneously from birth.
This study investigated the effects of enzyme and/or sodium butyrate supplementation on the performance, eggshell quality, pancreatic enzyme activities and jejunum histology of laying quails-fed diets containing sunflower meal (SFM). A total of 140 24-week-old quails were randomly allocated into five experimental groups with 14 replicates each. The treatment diets were: NC (negative control without SFM), PC (positive control with 25% SFM), PC+E (PC + 500 g/tonne multi-enzyme), PC+B (PC + 1000 g/tonne sodium butyrate) and PC+EB (PC + 500 g/tonne multi-enzyme + 1000 g/tonne sodium butyrate).
As a result of this study, egg production was significantly higher in PC, PC+E and PC+EB groups compared to NC, while feed intake increased in PC but decreased with enzyme and/or sodium butyrate supplementation. Eggshell-breaking strength was highest in PC+B, whereas eggshell ratio and thickness increased across all groups compared to NC. Pancreatic lipase activity increased in PC+E and PC+B, but pancreatic amylase and protease activities decreased in all treatments compared to NC. Villus height (VH) and crypt depth (CD) improved with enzyme and/or sodium butyrate supplementation, with villus width and surface area significantly greater in PC+E and PC+EB. However, the VH/CD ratio decreased in all groups except PC+EB. In conclusion, diets containing 25% SFM did not impair performance or egg quality and improved eggshell thickness and ratio. Enzyme and/or sodium butyrate supplementation reduced feed intake enhanced pancreatic lipase activity, decreased amylase and protease activities and improved jejunum histology, with sodium butyrate notably increasing eggshell-breaking strength.