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Monkeypox virus (MPXV) is a contagious disease that has been endemic in central and west Africa since 1970, characterized by symptoms such as fever, headache, and skin rash. While there is no approved treatment for MPXV infections, vaccination has proven effective in limiting its transmission, and previous smallpox vaccinations may also provide protection against monkeypox. However, the dependence of monkeypox on animal hosts makes eradication more complicated than with smallpox. Research should focus on assessing the safety of the vaccines, their duration of immunity, and their efficacy against the prevalent strains of monkeypox. The virus’s accelerated rate of mutation poses additional challenges, as does the fact that it can be transmitted through animals, making eradication more complex than with smallpox. A comprehensive global immunization strategy is needed to address these complexities and draw on lessons learned from past eradication efforts.
While constructing mathematical models, scientists usually consider biotic factors, but it is crystal-clear that abiotic factors, such as wind, are also important as biotic factors. From this point of view, this paper is devoted to the investigation of some bifurcation properties of a fractional-order prey–predator model under the effect of wind. Using fractional calculus is very popular in modelling, since it is more effective than classical calculus in predicting the system’s future state and also discretization is one of the most powerful tools to study the behaviour of the models. In this paper, first of all, the model is discretized by using a piecewise discretization approach. Then, the local stability of fixed points is considered. We show using the centre manifold theorem and bifurcation theory that the system experiences a flip bifurcation and a Neimark–Sacker bifurcation at a positive fixed point. Finally, numerical simulations are given to demonstrate our results.
Considering a double-indexed array $(Y_{n,i:\,n\ge 1,i\ge 1})$ of non-negative regularly varying random variables, we study the random-length weighted sums and maxima from its ‘row’ sequences. These sums and maxima may have the same tail and extremal indices (Markovich and Rodionov 2020). The main constraints of the latter results are that there exists a unique series in a scheme of series with the minimum tail index and the tail of the term number is lighter than the tail of the terms. Here, a bounded random number of series are allowed to have the minimum tail index and the tail of the term number may be heavier than the tail of the terms. We derive the tail and extremal indices of the weighted non-stationary random-length sequences under a broader set of conditions than in Markovich and Rodionov (2020). We provide examples of random sequences for which the assumptions are valid. Perspectives in adopting the results in different application areas are formulated.
Reflection of a rightward-moving shock over a steady oblique shock, equivalent to a shock-on-shock interaction, is typically studied with post-formed shock waves. Law, Felthun and Skews (Shock Waves, vol. 13, 2003, pp. 381–394) reported post-formed expansion fan (PFEF) reflection for second-family incident shock. Here, we show that PFEF reflection also exists for first-family incident shock. We derive the critical condition for PFEF reflection in the shock speed Mach number and incident shock angle plane. Our findings indicate PFEF emergence near type post-I region. Numerical simulations reveal that PFEF with rising incident angle can intersect the incident shock, triple point or Mach stem, echoing the Hillier (J. Fluid Mech., vol. 575, 2007, pp. 399–424) three-type classification of shock–expansion fan interactions. The complex shock reflection pattern is essentially composed of an upstream structure linked to the moving shock wave, and a downstream structure linked to the unperturbed oblique shock wave. Under the conditions investigated, the upstream structure is characterized by a Mach reflection of the incident shock over the wall, potentially featuring a triple point formed within the Mach stem. Below this triple point, there is a curved segment of the Mach stem that is close to the wall. As the inclined angle increases, the curved shock may expand and interact with the incident shock, leading to an asymmetric regular reflection, which is a phenomenon that has not been observed previously. The downstream structure is a double $\lambda$ shock structure, with the lower shock resulting from the generation of recompression shock waves.
The objective was to evaluate the influence of supplementation of L-arginine at 10 g/kg on the performance of lactating sows and their litters by evaluating the milk amino acid composition, serum hormone levels, mammary tissue redox status indicators, mammary tissue histomorphology, and the expression of genes related to mammary gland metabolism. The study was conducted in the municipality of Oliveira, Minas Gerais, Brazil, in 2019. A total of 24 sows were selected. A completely randomized design was used in a 2 × 3 factorial arrangement, with two diets (control and 10 g L-arginine/kg) and three mammary gland positions (thoracic, abdominal and inguinal), totaling six treatment groups. Each dietary treatment consisted of 12 replicates, with each replicate equivalent to one experimental unit, which was considered a sow and its litter. Females that were fed a diet supplemented with L-arginine had lower feed intake and greater weight loss. Piglets from sows that received L-arginine supplementation presented reduced weaning weight variation. L-arginine supplementation did not affect the amino acid composition of the milk, the plasma hormone levels of the sows, the oxidative stress parameters of redox, or breast tissue morphology. However, it may modulate the expression of genes important for mammary gland metabolism, such as the COX1 and SLC27A4. Piglets that suckled teats in the thoracic and abdominal positions had higher mean weights at 14 and 23 days, as well as greater daily weight gains. L-arginine supplementation to sows improves litter quality by increasing weaning weight uniformity; piglets that occupy the thoracic and abdominal positions perform better.
This paper presents a low-profile, triple-band elliptical coplanar waveguide-fed antenna designed using the split-ring resonator technique. An artificial magnetic conductor with three zero-phases of the reflection coefficient is incorporated as a reflector to improve the antenna gain. The results show a gain enhancement of 3.4, 5.65, and 1.5 dBi at the three frequency bands of interest centered on 2.45, 5.2, and 8 GHz, respectively. The first two operational bands are Industrial, Scientific and Medical bands (2.33–2.59 and 4.97–5.48 GHz) that can be particularly used for wireless local area network and Bluetooth applications, while the third band (7.48-8.59 GHz) is suitable for military and satellite communications. The proposed solution that is designed, fabricated, and tested exhibits a good agreement between measured and simulated results.
I argue in this article that, contrary to some recent views, Berkeley's bundle theory of physical objects is incompatible with the thinking that we immediately perceive such objects. Those who argue the contrary view rightly stress that immediate perception of ideas or objects must be non-conceptual for Berkeley, that is, the concept of the object cannot be made use of in the perception, otherwise it would be mediate perception. After a brief look at the texts, I contrast how a direct realist view of immediate perception differs significantly from a bundle theorist's view. The difference is so great that one rationale for the alternative view, the claim that Berkeley allies himself with common sense by claiming we immediately perceive physical objects, loses plausibility.
This article presents the psalm differentiae in the fifteenth-century Olivetan Psalter kept at the Łódź Archdiocesan Museum, the only book of this provenance that has been identified in Poland. The author identifies psalm differentiae and determines the degree to which they belong to the most widely applied euouae schemata in musical manuscripts and to what extent this book may contains euouae melodic variants without a correspondence in the chant tradition. The codex contains single psalm cadences which, if confirmed by further source research, may be considered original.
Local shearing motions in turbulence form small-scale shear layers, which are unstable to perturbations at approximately 30 times the Kolmogorov scale. This study conducts direct numerical simulations of passive-scalar mixing layers in a shear-free turbulent front to investigate mixing enhancements induced by such perturbations. The initial turbulent Reynolds number based on the Taylor microscale is $ Re_\lambda = 72$ or 202. The turbulent front develops by entraining outer fluid. Weak sinusoidal velocity perturbations are introduced locally, either inside or outside the turbulent front, or globally throughout the flow. Perturbations at this critical wavelength promote small-scale shear instability, complicating the boundary geometry of the scalar mixing layer at small scales. This increases the fractal dimension and enhances scalar diffusion outward from the scalar mixing layer. Additionally, the promoted instability increases the scalar dissipation rate and turbulent scalar flux at small scales, facilitating faster scalar mixing. The effects manifest locally; external perturbations intensify mixing near the boundary, while internal perturbations affect the entire turbulent region. The impact of perturbations is consistent across different Reynolds numbers when the amplitudes normalised by the Kolmogorov velocity are the same, indicating that even weaker perturbations can enhance scalar mixing at higher Reynolds numbers. The mean scalar dissipation rate increases by up to 50 %, even when the perturbation energy is only 2.5 % of the turbulent kinetic energy. These results underscore the potential to leverage small-scale shear instability for efficient mixing enhancement in applications such as chemically reacting flows.
Industrial robots are widely utilized in the machining of complex parts because of their flexibility. However, their low positioning accuracy and spatial geometric error characteristics significantly limit the contour precision of robot machined parts. Therefore, in the robot machining procedure, an in situ measurement system is typically required. This study aims to enhance the trajectory accuracy of robotic machining through robotic in situ measurement and meta-heuristic optimization. In this study, a measurement-machining dual-robot system for measurement and machining is established, consisting of a measurement robot with a laser sensor mounted at the robot end and a machining robot equipped with a machining tool. In the measuring process, high-precision standard spheres are set on the edge of the machining area, and the high-precision standard geometry is measured by the measurement robot. According to measured geometry information in the local area, the trajectory accuracy for the machining robot is improved. By utilizing the standard radius of the standard spheres and adopting a meta-heuristic optimization algorithm, this study addresses the complexity of the robot kinematics model, while also overcoming local optima commonly introduced by gradient-based iterative methods. The results of the experiments in this study confirm that the proposed method markedly refines the precision of the robot machining trajectory.
A circularly polarized broadband antenna is designed for Wi-Fi 7 applications. The patch antenna is modeled in the shape of G, and the feed position is adjusted to produce the arms with a length difference of λ/4. The G-shaped patch antenna has shown an impedance bandwidth of 5% (6.16−6.48 GHz) and a peak gain of 6.3 dBi. The metasurface is structured with a periodic array of 4 × 4 patches. The metasurface is sandwiched between dielectric substrates beneath the G-shaped patch. The outcome of these combinations has achieved an impedance bandwidth of 41% (4.85−7.37 GHz) and an axial ratio bandwidth of 26% (5.26−6.83 GHz), and the antenna achieved a peak gain of 7.45 dBic.
Diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae), a globally distributed insect, is a major pest of crucifer crops due to its adaptability to diverse climates. In Argentina, its distribution spans three regions: a core area in the northeast and central-east where it persists year-round, a southwestern region with seasonal migrations, and an intermediate zone with variable year-round persistence. Across these areas, it is the primary pest of Brassica crops. In the central-east, the availability of year-round Brassicaceae crops and wild species indicates that seasonality is not linked to food scarcity. While studies have examined this relationship elsewhere, thermal thresholds vary among populations, and limited data on South American populations highlight the need for localised research. This study evaluated thermal thresholds for P. xylostella populations in central Argentina, focusing on temperature’s effects on fecundity, fertility, development, and survival. We found that temperatures outside the optimal range (15–23°C) significantly reduced survival, with no individuals surviving at 5 or 30°C. Linear and non-linear models accurately described the relationship between temperature and pest development. Using cumulative degree-days, we mapped potential P. xylostella generations across central Argentina. This research provides the first comprehensive analysis of P. xylostella thermal biology in temperate Argentina, emphasising temperature’s critical role in its development. The findings offer valuable insights for climate-specific pest management strategies and enhance understanding of insect population dynamics in agricultural ecosystems, contributing to more sustainable control practices.
Comparative scholarship suggests authoritarian candidates often rely on backing from the wealthy. The wealthy are also said to play an important role in American campaign finance. Studies of Donald Trump, however, found that he drew significant support from white Americans with less education and privilege. We evaluate wealthy and non-wealthy Americans’ financial support for Trump, compared to other candidates, by constructing a comprehensive dataset of property values matched to contributions and voter files. We find Trump underperformed among wealthy Republican donors while mobilizing new non-wealthy donors. Trump also diversified the donorate, especially by education. That is, Trump built an unusual coalition of wealthy and non-wealthy donors. Our results support an alternative, “plutopopulist” model of Trump’s financial base. This study demonstrates the importance of studying both non-wealthy and wealthy Americans, the group who give the most but whose individual behavior has been studied the least.
Unmanned aerial vehicles (UAVs) with fully electric propulsion systems mainly use lithium-based batteries. However, using fuel cells, hybrid propulsion systems are created to improve the flight time and payload capacity of the UAVs. Energy management and energy-aware path planning are important aspects to be explored in hybrid-propulsion powered UAV configurations. These facilitate optimal power distribution among energy sources and motion planning considering energy consumption, respectively. In the literature, although there are many studies on the energy management of hybrid-powered UAVs and path planning of only battery-powered UAVs, there are research gaps in energy-aware path planning of hybrid-powered UAVs. Additionally, the energy management of hybrid-powered UAVs is usually considered independent of path planning in the literature. This paper thoroughly reviews recent energy-aware path planning for small UAVs to address the listed critical challenges above, providing a new perspective and recommendations for further research. Firstly, this study evaluates the recent status of path planning, hydrogen-based UAVs, and energy management algorithms and identifies some challenges. Later, the applications of hydrogen-powered UAVs are summarised. In addition, hydrogen-based hybrid power system topologies are defined for small UAVs. Then, the path-planning algorithms are classified, and existing studies are discussed. Finally, this paper provides a comprehensive and critical assessment of the status of energy-aware path planning of UAVs, as well as detailed future work recommendations for researchers.
This article, set in El Paso, Texas, in 1908, concerns immigration inspector Robert L. Dodd who was accused and administratively removed by the federal Immigration Bureau for facilitating the introduction of undocumented Japanese immigrants into the United States. The article examines the government’s case against Dodd and argues that his dismissal was not only a miscarriage of justice but also may have been structured to scapegoat Dodd as part of the ongoing efforts in the Progressive Era toward civil service reforms within federal service.