We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
This paper introduces a novel ray-tracing methodology for various gradient-index materials, particularly plasmas. The proposed approach utilizes adaptive-step Runge–Kutta integration to compute ray trajectories while incorporating an innovative rasterization step for ray energy deposition. By removing the requirement for rays to terminate at cell interfaces – a limitation inherent in earlier cell-confined approaches – the numerical formulation of ray motion becomes independent of specific domain geometries. This facilitates a unified and concise tracing method compatible with all commonly used curvilinear coordinate systems in laser–plasma simulations, which were previously unsupported or prohibitively complex under cell-confined frameworks. Numerical experiments demonstrate the algorithm’s stability and versatility in capturing diverse ray physics across reduced-dimensional planar, cylindrical and spherical coordinate systems. We anticipate that the rasterization-based approach will pave the way for the development of a generalized ray-tracing toolkit applicable to a broad range of fluid simulations and synthetic optical diagnostics.
We propose a two-sided market entry game and present experiments studying coordination behavior in the game. The two-sided market in the game is operated by an intermediary monopoly platform, serving two sides (i.e., customers and service providers) and featuring asymmetric agents, cross-side network effects, and endogenous market capacity. The game has multiple pure-strategy Nash equilibria if at least one side has a high willingness to enter the market and the other side’s willingness is not very low. We conduct a laboratory experiment involving three treatments corresponding to different combinations of willingness to enter the market among customers and service providers. The experimental results indicate that willingness to enter the market and cross-side network effects significantly influence coordination behavior in two-sided markets. When the multiple pure-strategy Nash equilibria are Pareto ranked on both sides, customers and service providers can coordinate their behavior to the payoff-dominant equilibrium via tacit coordination under strategic uncertainty. However, when the multiple pure-strategy Nash equilibria are Pareto ranked on one side but Pareto equivalent on the other side, coordination failure and disequilibrium occurred, and the equilibria cannot predict the aggregate behavior well. Our experimental results indicate that a thriving two-sided market should coordinate both sides on board.
Manganese (Mn) is a crucial trace element that actively participates in a diverse array of physiological processes. Mn is maintained at appropriate levels in the body by absorption and excretion by the body. Dysregulation of Mn homeostasis can lead to a variety of diseases, especially the accumulation of Mn in the brain, resulting in toxic side effects. We reviewed the metabolism and distribution of Mn at multiple levels, including organ, cellular, and sub-cell levels. Mitochondria are the main sites of Mn metabolism and energy conversion in cells. Enhanced Mn superoxide dismutase activity reduces mitochondrial oxidative stress and inhibits cancer development. In addition, Mn enhances anticancer immune responses through the cGAS-STING pathway. We introduced various delivery vectors for Mn delivery to cancer sites for Mn supplementation and anti-cancer immunity. This review aims to provide new research perspectives for the application of Mn in the prevention and treatment of human diseases, especially by enhancing anticancer immune responses to inhibit cancer progression.
This study explored mental workload recognition methods for carrier-based aircraft pilots utilising multiple sensor physiological signal fusion and portable devices. A simulation carrier-based aircraft flight experiment was designed, and subjective mental workload scores and electroencephalogram (EEG) and photoplethysmogram (PPG) signals from six pilot cadets were collected using NASA Task Load Index (NASA-TLX) and portable devices. The subjective scores of the pilots in three flight phases were used to label the data into three mental workload levels. Features from the physiological signals were extracted, and the interrelations between mental workload and physiological indicators were evaluated. Machine learning and deep learning algorithms were used to classify the pilots’ mental workload. The performances of the single-modal method and multimodal fusion methods were investigated. The results showed that the multimodal fusion methods outperformed the single-modal methods, achieving higher accuracy, precision, recall and F1 score. Among all the classifiers, the random forest classifier with feature-level fusion obtained the best results, with an accuracy of 97.69%, precision of 98.08%, recall of 96.98% and F1 score of 97.44%. The findings of this study demonstrate the effectiveness and feasibility of the proposed method, offering insights into mental workload management and the enhancement of flight safety for carrier-based aircraft pilots.
China has made nationalism central as the country seeks to achieve a 'rejuvenation of the Chinese nation'. The new wave of consumer nationalism in China reached a fever pitch in recent years. This book will be the first book that systematically analyzes the different waves of consumer nationalism in China, the types of its nationalistic consumer actions, and the critical impact of the new wave which has increased the possibility of a consumer base that could turn hostile at any moment.
It argues that the outbursts of nationalist consumer outrage have become an increasing risk for businesses in China or businesses dealing with Chinese markets and that as China faces growing diplomatic challenges abroad, multinational companies need to enhance focus and strategic planning in communication operations when dealing with the world's second-largest economy.
Rare earth elements (REEs) preserved in speleothems have garnered increasing attention as ideal proxies for the paleoenvironmental reconstruction. However, due to their typically low contents in stalagmites, the availability of stalagmite-based REE records remains limited. Here we present high-resolution REEs alongside oxygen isotope (δ18O) records in stalagmite SX15a from Sanxing Cave, southwestern China (110.1–103.3 ka). This study demonstrates that REE records could provide useful information for the provenance and formation process of the stalagmite, due to consistent distribution pattern across different periods indicating stable provenance. More interestingly, the total REE (ΣREE) record could serve as an effective indicator to reflect local hydrological processes associated with monsoonal precipitation. During Marine Isotopic Stage (MIS) 5d, a relatively low ΣREE content is consistent with the positive SX15a δ18O and negative NGRIP δ18O, reflecting a dry-cold environment; while during MIS 5c, a generally high ΣREE content suggests a humid-warm circumstance. Furthermore, the ΣREE record captured four prominent sub-millennial fluctuations within the Greenland interstadial 24 event, implying a combined influence by the regional climate and local soil redox conditions. Our findings indicate that the stalagmite-based REE records would be a useful proxy for better understanding of past climate and environment changes.
This paper focuses on the averaging principle concerning the fast–slow McKean–Vlasov stochastic differential equations driven by mixed fractional Brownian motion with Hurst parameter $\tfrac{1}{2} < H < 1$. The integral associated with Brownian motion is the standard Itô integral, while the integral with respect to fractional Brownian motion is a generalized Riemann–Stieltjes integral. Under the non-Lipschitz condition and certain appropriate assumptions regarding the coefficients, we initially establish the existence and uniqueness theorem for the fast–slow McKean–Vlasov stochastic differential equation driven by mixed fractional Brownian motion. Subsequently, we demonstrate the averaging principle of the fast–slow McKean–Vlasov stochastic differential equations, signifying that the slow stochastic differential equation converges to the associated averaged equation in terms of mean-square convergence.
Alcohol use disorder is a global public health concern and national policies are often implemented to help control alcohol consumption and related consequences. Increasingly, many countries are resorting to transient (short-term) alcohol policies which are implemented for a restricted period of time as an action plan for particular events or health-related issues. The COVID-19 pandemic emphasised the need for rapid decision-making and short-term fast-acting policies. This paper discusses contexts in which these transient policies are used and highlights the need for impact measurement and global exchange of experiences. This is particularly important to avoid gaps that the global alcohol industry could utilise to expand its influence and market.
To identify risk factors for catheter-related bloodstream infections (CRBSI) in cancer patients, we compared 200 CRBSI cases to 400 controls. Neutropenia, transplants, multiple catheters, blood products, and basilic/cephalic PICCs increased CRBSI risk, while jugular insertion was protective. Catheter site selection can reduce risk. Other targeted strategies are warranted.
Advertising click-through rate (CTR) prediction is a fundamental task in recommender systems, aimed at estimating the likelihood of users interacting with advertisements based on their historical behavior. This prediction process has evolved through two main stages: from traditional shallow interaction models to more advanced deep learning approaches. Shallow models typically operate at the level of individual features, failing to fully leverage the rich, multilevel information available across different feature sets, leading to less accurate predictions. In contrast, deep learning models exhibit superior feature representation and learning capabilities, enabling a more realistic simulation of user interactions and improving the accuracy of CTR prediction. This paper provides a comprehensive overview of CTR prediction algorithms in the context of recommender systems. The algorithms are categorized into two groups: shallow interactive models and deep learning-based prediction models, including deep neural networks, convolutional neural networks, recurrent neural networks, and graph neural networks. Additionally, this paper also discusses the advantages and disadvantages of the aforementioned algorithms, as well as the benchmark datasets and model evaluation methods used for CTR prediction. Finally, it identifies potential future research directions in this rapidly advancing field.
Lactoferrin (LF), a sialylated iron-binding glycoprotein consisting of multiple sialic acid (Sia) residues attached to N-linked glycan chains, and studies have shown that both the iron and Sia are crucial for early neurodevelopment and cognition.(1) However, there is limited knowledge of the impacts of the iron saturation and sialylation in LF molecule on the early neurodevelopment and cognition. Objectives of the study were to explore the impacts and mechanisms of iron saturation and sialylation in LF molecule on early neurodevelopment and cognition. Maternal dietary intervention with native bovine LF (Native-LF), iron-free bovine LF (Apo-LF), or Sia-free bovine LF (Desia-LF) at a dose of 0.60 g/kg body weight per day was administered throughout the lactation period. Offspring pups were assessed for anxiety, learning, and memory through behavioral tests before being euthanized on postnatal day 63. Brain hippocampal tissue was then analyzed for polysialic acid (polySia), a marker of neurodevelopment and neuroplasticity.(1) The study protocol was approved by the Xiamen University Animal Ethics Committee (AE1640102). Our results showed that Apo-LF pups exhibited a 1.32-fold increase in total distance travelled in the arena compared to both Native-LF and Desia-LF groups, with the overall difference among the groups being statistically significant in the open field test (p = 0.008). Additionally, the frequency of central area entries in the Apo-LF group was 2.00-fold higher than in Desia-LF pups (p = 0.038) and 1.3-fold higher than in Native-LF pups, with a significant overall difference (p = 0.042). No significant differences in total distance travelled or central area entries were observed between Native-LF and Desia-LF groups (p > 0.05). These results suggest that Apo-LF pups demonstrated better anti-anxiety behaviors than both Native-LF and Desia-LF pups. In the Morris water maze test, Apo-LF pups spent significantly more time in the target quadrant compared to both Desia-LF (p = 0.019) and Native-LF pups (p = 0.0009), indicating enhanced short-term memory. Additionally, Apo-LF pups exhibited greater polySia-NCAM expression (1.2.95 ± 0.048) in the hippocampus, a marker associated with neuroplasticity and neurogenesis compared to both Native-LF and Desia-LF pups. We conclude that maternal supplementation with different types of lactoferrin during lactation supports improved learning and memory in offspring through distinct mechanisms, with sialylation playing a crucial role in neurocognitive development.
To capture the airspeed-dependent dynamics of flexible aircraft, high-order aeroservoelastic systems can generally be expressed as linear parameter-varying (LPV) models. This paper presents a comprehensive model order reduction and control design process for grid-based LPV systems, and takes the flexible aircraft FLEXOP as an example for verification. The LPV model order reduction method is extended from projection-based linear time-invariant methods through construction of continuous transformations. The corresponding algorithm can be programmed to automatically perform the model order reduction for LPV systems and simultaneously ensure the state consistency between grid points and the continuity of state-space data interpolation. By applying this method, a 680th-order high-fidelity LPV model of the FLEXOP aircraft is reduced to a control-oriented model with only 19 states. Considering that the frequencies of rigid-body and flexible modes are close under certain parameter conditions, an integrated design approach for rigid-flexible coupling control is employed in this paper. Instead of separately designing a baseline rigid-body flight controller and a flutter suppression controller for each unstable flexible mode, a parameter-dependent dynamic output-feedback controller is designed. The resulting controller effectively expands the flutter-free flight envelope, ensuring rigid-body attitude and velocity tracking performance while stabilising the two originally unstable flutter modes.
The selection of random sampling points is crucial for the path quality generated by probabilistic roadmap (PRM) algorithm. Increasing the number of sampling points can enhance path quality. However, it may also lead to extended convergence time and reduced computational efficiency. Therefore, an improved probabilistic roadmap algorithm (TL-PRM) is proposed based on topological discrimination and lazy collision. TL-PRM algorithm first generates a circular grid area among start and goal points. Then, it constructs topological nodes. Subsequently, elliptical sampling areas are created between each pair of adjacent topological nodes. Random sampling points are generated within these areas. These sampling points are interconnected using a layer connection strategy. An initial path is generated using a delayed collision strategy. The path is then adjusted by modifying the nodes on the convex outer edges to avoid obstacles. Finally, a reconnection strategy is employed to optimize the path. This reduces the number of path waypoints. In dynamic environments, TL-PRM algorithm employs pose adjustment strategies for semi-static and dynamic obstacles. It can use either the same or opposite pose adjustments to avoid dynamic obstacles. Experimental results indicate that TL-PRM algorithm reduces the average number of generated sampling points by 70.9% and average computation time by 62.1% compared with PRM* and PRM-Astar algorithms. In winding and narrow passage maps, TL-PRM algorithm significantly decreases the number of sampling points and shortens convergence time. In dynamic environments, the algorithm can adjust its pose orientation in real time. This allows it to safely reach the goal point. TL-PRM algorithm provides an effective solution for reducing the generation of sampling points in PRM algorithm.
Microplastic pollution from plastic fragments accumulating in agricultural fields threatens the world’s most productive soils and environmental sustainability. This is the first paper to address the challenge of developing a dynamic economic model to analyze the adoption of soil-biodegradable plastic mulches (BDMs) as a sustainable alternative to conventional polyethylene mulches. The model considers the trade-off between BDM degradation rates and agricultural production, seeking to balance the cost of BDMs and the cost of waste disposal. We consider both private and social perspectives under deterministic and stochastic environments. Our findings suggest that BDMs can significantly decrease long-term plastic pollution from single-use plastics in agriculture. For example, increasing landfill tipping fees incentivizes Washington State tomato growers to optimally adopt BDMs with a 61% degradation rate and to till used BDMs into the soil, reducing plastic waste accumulation in landfills. The study highlights the role of economic incentives, such as landfill fees, corrective taxes and the role of risk aversion, in promoting BDM adoption and curbing plastic pollution. The framework presented here offers valuable insights for policymakers and stakeholders seeking to foster sustainable agricultural practices and mitigate global plastic pollution.
In this study, we investigate the sedimentation of spheroidal particles in an initially quiescent fluid by means of particle-resolved direct numerical simulations. Settling particles with three different shapes – oblate spheroid, sphere and prolate spheroid – but fixed Galileo number $Ga=80$ and density ratio $\gamma =2$ at volume fraction $\phi =1\%$ are considered. Oblate and prolate particles are found to form column-like clusters as a consequence of the wake-induced hydrodynamic interactions in the suspension. This effect, together with the change of particle orientation, enhances the mean settling velocity of the dispersed phase. In contrast, spherical particles do not exhibit clustering, and settle with hindered velocity in the suspension. Furthermore, we focus on the pseudo-turbulence induced by the settling particles. We report a non-Gaussian distribution of the fluid velocity and a robust $-3$ power law of the energy spectra. By scrutinizing the scale-by-scale budget, we find that the anisotropy of the particle-induced pseudo-turbulence is manifested not only by the uneven allocation of turbulence kinetic energy among the different velocity components, but also by the anisotropic distribution of energy in spectral space. The fluid–particle interactions inject energy into the vertical velocity component, thus sustaining the turbulence, while pressure redistributes the kinetic energy among the different velocity components. The clustering of oblate/prolate particles significantly increases the energy input at large scales, forcing elongated flow structures. Moreover, the redistribution and nonlinear transfer of the energy are also intensified in the presence of particle clustering, which reduces the anisotropy of the particle-induced pseudo-turbulence.
This study presents a novel investigation into the vortex dynamics of flow around a near-wall rectangular cylinder based on direct numerical simulation at $Re=1000$, marking the first in-depth exploration of these phenomena. By varying aspect ratios ($L/D = 5$, $10$, $15$) and gap ratios ($G/D = 0.1$, $0.3$, $0.9$), the study reveals the vortex dynamics influenced by the near-wall effect, considering the incoming laminar boundary layer flow. Both $L/D$ and $G/D$ significantly influence vortex dynamics, leading to behaviours not observed in previous bluff body flows. As $G/D$ increases, the streamwise scale of the upper leading edge (ULE) recirculation grows, delaying flow reattachment. At smaller $G/D$, lower leading edge (LLE) recirculation is suppressed, with upper Kelvin–Helmholtz vortices merging to form the ULE vortex, followed by instability, differing from conventional flow dynamics. Larger $G/D$ promotes the formation of an LLE shear layer. An intriguing finding at $L/D = 5$ and $G/D = 0.1$ is the backward flow of fluid from the downstream region to the upper side of the cylinder. At $G/D = 0.3$, double-trailing-edge vortices emerge for larger $L/D$, with two distinct flow behaviours associated with two interactions between gap flow and wall recirculation. These interactions lead to different multiple flow separations. For $G/D = 0.9$, the secondary vortex (SV) from the plate wall induces the formation of a tertiary vortex from the lower side of the cylinder. Double-SVs are observed at $L/D = 5$. Frequency locking is observed in most cases, but is suppressed at $L/D = 10$ and $G/D = 0.9$, where competing shedding modes lead to two distinct evolutions of the SV.