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The ability of multirotor unmanned aerial vehicles (UAVs) to perform accurately in windy environments is crucial for extended use in outdoor applications. To design UAVs to operate in these environments, most studies have focused on static performance metrics such as thrust-to-weight ratio and endurance, without directly considering closed-loop control performance. This work develops a simplified metric that serves as a predictor for achievable disturbance rejection performance, enabling efficient UAV design selection without requiring full-scale nonlinear simulations. A reduced-order model is introduced to capture key aerodynamic and actuation characteristics, allowing for rapid evaluation of UAV configurations. The metric is validated against high-fidelity nonlinear simulations, demonstrating strong correlation with actual control performance. By bridging the gap between UAV structural optimization and closed-loop control behavior, this approach provides a practical tool for integrating disturbance rejection capabilities into UAV design processes. The practical utility of this metric is supported by experimental findings from related wind tunnel studies of fully-actuated UAVs, which demonstrate that actual disturbance rejection performance aligns with the trends predicted by the simplified correlation function.
The linear instability of liquid film with insoluble surfactants on a quasiperiodic oscillating plane for disturbances with arbitrary wavenumbers is investigated. The combined effects of insoluble surfactants and quasiperiodic oscillation on the instability are described using Floquet theory. For long-wavelength instability, the solution in the limit of long wave perturbations is obtained by the asymptotic expansion method. The results show that a new stable region emerges in the low-frequency domain of the neutral stability curve in the absence of gravity. As the imposed frequency increases, this newly formed stable region is progressively absorbed into a broader stable zone. The U-shaped neutral curves with separation bandwidth appear in the presence of gravity, and the presence of the surfactants will decrease the unstable frequency bandwidth and increase the critical Reynolds number. The finite-wavelength instability is solved numerically based on the Chebyshev spectral collocation method. Both travelling-wave and standing-wave modes are found due to the existence of surface surfactants. As the surfactant concentration increases, the finite-wavelength instability region expands significantly, and the intersection point marking the transition from travelling waves to standing waves shifts progressively towards lower frequencies. The physical mechanisms underlying perturbation growth are further elucidated through an energy budget analysis. Energy budget analysis demonstrates that long-wavelength instability is dominated mainly by surface shear stress, whereas finite-wavelength instability is primarily governed by the combined effects of Reynolds stress and surface shear stress.
Research syntheses have demonstrated that pronunciation instruction works, which means that whether instruction is effective is no longer an open question. Instead, contemporary intervention research has shifted to investigating how instruction can be further optimized, asking targeted questions about the instructional features that catalyze learning. In this paper, I examine the concept of instructional optimization, focusing on anticipated effect sizes (gains). I outline a four-pronged empirical approach to provide robust data for designing optimal pronunciation interventions. First, I describe the need for replication studies, which provide insight into the precision and stability of effects across distinct research samples and contexts. Second, I advocate for a systematic approach to study design. In such an approach, which is closely tied to the principles of replication, one or two variables are manipulated at a time, leading to a set of maximally comparable studies that lend insight into the impact of specific variables. Third, I explain the need to situate instruction within a longitudinal perspective to examine how robust and durable instructional gains are. Finally, I turn to adaptive approaches, where the surface format that instruction takes is highly variable and responsive to learner needs while the adaptive decision tree that generates the form is fixed and replicable.
This is a study of how opposing cultural values influence support for minorities’ civil liberties. We build on a rich body of work, which establishes that culturally liberal Europeans are more likely to value diversity and favor minority rights than are cultural conservatives. Our contribution is to bring attention to how a second dimension of value conflict upends this established pattern. If a religious minority, in this case Muslims, wants to use their religious freedom to call on Muslims to adhere to conservative Islamic values – to preach them – support for their civil liberties plunges. We report substantively large and remarkably consistent results from seven classical tolerance experiments conducted in three European countries. In each trial, we observe the tendency of non-Muslims to deny Muslims their right to freedom of religion. We consistently observe that culturally liberal citizens join cultural conservatives in turning against Muslims’ right to hold a public rally when Muslims intend to exercise their right to freedom of expression to preach (the speech-act dimension) culturally conservative ideas in Islam (the substantive dimension). Preaching is a performative utterance, an instance of when saying something is doing something. What is being done, in addition to what is being said, is to call for compliance. This study finds that conflicts with religiously grounded values in contemporary European liberal democracies often have an additional order of intensity, because stating religious beliefs in the form of performative utterances is an integral part of religious practice.
This paper reports analytical solutions for steadily travelling two-dimensional water waves on deep water, without gravity or surface tension, carrying a cotravelling periodic row of hollow vortices. The solutions are hollow-vortex regularisations of the exact solutions of Crowdy & Roenby (Fluid Dyn. Res., vol. 46, 2014, 031424) for the analogous waves carrying a submerged point-vortex row, the free-surface shapes of which coincide with those for pure capillary waves and, like those, exhibit steady pinchoff at a critical wave amplitude. The same pinchoff phenomenon is shown to occur for the hollow-vortex regularisations. The new wave solutions are likely to provide a useful basis for perturbative, asymptotic or numerical studies when additional effects such as gravity, capillarity or compressibility are incorporated.
Cardiac hydatidosis accounts for less than 2% of Echinococcus granulosus infections. Despite Syria’s high endemicity, paediatric cardiac involvement remains exceptionally rare and underreported. We report two Syrian children (aged 5.5 and 9 years) with giant interventricular septal hydatid cysts. Case 1 presented with significant hemodynamic obstruction, while Case 2 exhibited malignant ventricular arrhythmias. Both underwent successful cardiopulmonary bypass-assisted cystectomy with capitonnage repair and adjuvant albendazole therapy. These cases underscore (1) the life-threatening nature of advanced paediatric cardiac hydatidosis and (2) the critical role of early surgical intervention in endemic regions. Written informed consent for publication was obtained.
To test the ‘Investigate Exposure’ step of the WHO’s CLICK framework, and to investigate 12–16-year-old children’s exposure to paid-for digital food advertising in Finland.
Design:
The DIGITUTKA pilot study was carried out as part of the EU Joint Action Best-ReMap project. Data on paid-for digital food advertising that children were exposed to via their phones over a two-weeks period were captured using the RealityMeter-application, following the ‘Investigate Exposure’ step of the CLICK framework. Data were collected between April and June 2022 and analyzed in Excel, following a protocol outlined by WHO Europe. The WHO Europe Nutrient Profile Model (v1, 2015) was used to determine marketing permission.
Setting:
Four schools in Finland
Participants:
6th-9th grade students (n=34)
Results:
Out of the 17 820 captured advertisements, 2316 (13%) were identified as food or beverage brands and products. The most commonly advertised products were convenience foods, composite dishes (16%, N=372), and energy drinks (9%, N=202). The majority of the food and beverage advertisements (N=1291, 56%) were not permitted to be marketed to children, with only one in ten (N=222, 9%) was permitted to be marketed to children. A third (35%) of the food and beverage advertisements could not be identified due to missing information.
Conclusions:
Children were exposed to a large number of food and beverage advertisements, most of which were not permitted to be marketed to children. To protect children’s health and prevent obesity, marketing restrictions should be combined with broader changes to the food environment and taxation.
Citrus leprosis is a non-systemic disease caused by citrus leprosis virus (CiLV), which is classified as cytoplasmic (CiLV-C) or nuclear (CiLV-N) based on its replication site within host cells. Mite species in the genus Brevipalpus vector this virus. In Mexico, B. californicus and B. yothersi have been recorded in citrus orchards, with the latter species being most abundant and widely distributed. Despite extensive research, knowledge gaps remain regarding interactions between Brevipalpus and CiLV-C, the predominant virus type. We investigated the vector competence of both species, with a detailed analysis of density-dependent acquisition and transmission for B. yothersi. Virus acquisition was assessed using three densities (5, 10, or 15 adult females) for B. yothersi and a single desity (15 mites) for B. californicus. Virus detection and quantification were performed using a TaqMan probes targeting the viral movement protein gene. Transmission assays were conducted on Phaseolus vulgaris plants using viruliferous B. yothersi at all densities. B. californicus did not acquire the virus and was therefore excluded from transmission experiments. In contrast, B. yothersi successfully acquired the virus at all densities. While the proportion of viruliferous mites did not differ significantly among density treatments, viral load per mite was significantly higher at the lowest density. Virus transmission ocurred at all densities, with no significant differences in viral titres in inoculated plants. There results provide insights into density-related mite-virus interactions affecting CiLV-C transmission.
A conservative formulation of the drift-reduced fluid plasma model is constructed by analytically inverting the implicit relation defining the polarisation velocity as a function of the time derivative of the electric field. The obtained model satisfies exact conservation laws for energy, mass, charge and momentum, in arbitrary magnetic geometry, also when electromagnetic fluctuations are included.
Overseas large-scale combat operations (LSCOs) could require domestic hospitals to treat large numbers of combat casualties. Our goal was to evaluate the financial impact on hospitals of treating combat casualties during an LSCO.
Methods
Using a discrete event simulation model, we explored how 5 civilian hospitals in Omaha, Nebraska, would fare after accepting combat casualties during a National Disaster Medical System (NDMS) activation. We compared changes in financial measures (government payments, hospital revenues) and occupancy measures (civilian patient displacement) under different scenarios for combat casualty reimbursement rates as fractions (75%-125%) of Medicare rates.
Results
Combat casualties replaced 100% of civilian patients at 3 of 5 hospitals, displacing a total of 10,905 civilian patients [95% CI: 10551-11248]. Combat casualty reimbursement at 125% of Medicare rates resulted in government payments of $462 million and net income gains for civilian hospitals of approximately 23 times pre-activation baselines. Combat casualty reimbursement below 125% of Medicare rates led to net income losses.
Conclusions
Large influxes of combat casualties could result in rapid, profound displacement of civilian patients and revenue loss at NDMS-participating facilities, potentially affecting hospitals’ ability and willingness to treat them. Policymakers need to identify appropriate reimbursement rates for combat casualties.
This paper investigates a specific culture of interdisciplinarity that has gained traction at the intersection of applied AI and ethics. To address social and ethical harms of AI applications, scholars have suggested importing norms, methodologies and governance frameworks from established disciplines such as the social sciences or medicine. I show how this importation presupposes and endorses a framing of applied AI as a domain separate from established disciplines. Yet, such separation is what initially allows AI practitioners to operate outside those disciplinary norms that have evolved to prevent harms now associated with AI applications. Conversely, if AI applications were understood as situated firmly within these disciplines, practitioners would already be accountable to their norms and standards. Paradoxically, this culture of interdisciplinarity might thus reinforce a problematic disciplinary isolation of applied AI underlying the very ethical issues it seeks to mitigate – fighting symptoms while playing into their cause. In response, I outline three paths forward.
The growth in economic inequality in the United States over the past forty years has stimulated interest among scholars in the effects of exposure to inequality on the American people. A prominent vein of scholarship explores whether exposure to inequality diminishes belief in a key pillar of the ‘American dream’ – the meritocratic ideal that hard work will translate to economic success. We offer this literature a novel test that explores the relationship between quotidian exposure to economic inequality in one’s adolescent residential context and belief in the American dream among roughly 1.3 million late-adolescent Americans entering college. We find that adolescent residence in high-inequality areas is associated with decreased belief in the American dream upon entering adulthood. Further analysis revealed that this relationship is most pronounced among young Americans raised in higher income households.
This paper engages with recent work on formalization in economics to develop a new perspective on mathematization. Boylan and O’Gorman draw on foundations of mathematics to argue that classical mathematics is inappropriate for economics; intuitionistic foundations and constructive mathematics should be used instead. The use of real analysis would be blocked and equilibrium results undermined. I argue that their line of thought faces several challenges; however, I then draw on their analyses and the philosophy of applied mathematics to propose a novel approach in which questions about mathematization are properly understood as questions about the contextual aptness of relevant idealizations.