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The motion of a sphere freely rising or falling in a 5d (d is the diameter of the sphere) square tube was numerically studied for the sphere-to-fluid density ratio ranging from 0.1 to 2.3 (0.1 ≤ ρs/ρ ≤ 2.3, ρs is the density of spheres and ρ the fluid density) and Galileo number from 140 to 230 (140 ≤ Ga ≤ 230). We report that Hopf bifurcation occurs at Gacrit ≈ 157, where both the heavy and light spheres lose stability. The helical motion is widely seen for all spheres at Ga > 160 resulting from a double-threaded vortex interacting with the tube walls, which becomes irregular at Ga ≥ 190 where heavy spheres act differently from their counterparts; that is, heavy spheres change their helical directions alternately while light spheres exhibit helical trajectories with jaggedness in connection with the shedding of the double-threaded vortices. This is because of the difference in inertia between the heavy and light spheres. We also checked the oscillation periods for the helical motion of the spheres. They show opposite variations with ρs/ρ for the two types of spheres. Light spheres (ρs/ρ ≤ 0.7) reach a zigzagging regime at Ga ≥ 200 where a vortex loop (hairpin-like vortical structure) is formed which may develop into a vortex ring downstream at small ρs/ρ. This might be the first time a transition from the helical motion to the zigzagging motion for heavy spheres (ρs/ρ ≥ 1.8) has been reported. Finally, we examined the dependence of both the terminal Reynolds number and the drag coefficient of the spheres on the Galileo number.
Mental health is deteriorating quickly and significantly globally post-COVID. Though there were already over 1 billion people living with mental disorders pre-pandemic, in the first year of COVID-19 alone, the prevalence of anxiety and depression soared by 25% worldwide. In light of the chronic shortages of mental health provider and resources, along with disruptions of available health services caused by the pandemic and COVID-related restrictions, technology is widely believed to hold the key to addressing rising mental health crises. However, hurdles such as fragmented and often suboptimal patient protection measures substantially undermine technology’s potential to address the global mental health crises effectively, reliably, and at scale. To shed light on these issues, this paper aims to discuss the post-pandemic challenges and opportunities the global community could leverage to improve society’s mental health en masse.
The flow-induced oscillation of an S-shaped buckled flexible filament was explored using the penalty immersed boundary method. As the length and bending rigidity of the filament were varied, three distinct modes emerged: the equilibrium mode, streamwise oscillation (SO) mode and transverse oscillation (TO) mode. A transition region between the SO and TO modes was identified. Notably, the filament exhibited a 3P wake pattern under SO and a 2S wake pattern under TO. The former was induced by fluid–elastic instability, while the latter was attributed to vortex-induced oscillation. The interaction between the filament's motion and vortex shedding was examined for both modes. To elucidate the disparity between the TO of the S-shaped buckled filament and snap-through oscillation (STO), a ball-on-a-hill analogy was introduced. The performance of energy harvesting was evaluated using metrics including the elastic energy and power coefficient. The TO mode was found to show significantly higher energy harvesting performance than the SO and STO modes. The majority of the strain energy was concentrated at the upper and lower midpoints of the filament.
(Re)visiting the testimony exhibition part of Women’s Active Museum on War and Peace in Tokyo, I focus on one testimony in particular. This testimony was given by a survivor of the “comfort women” system, a state-sponsored regime of military sexual exploitation and core institution in the Empire of Japan’s expansion 1932–1945. The testimony was then withheld before the exhibition opened. I approach this “withheld testimony” as an invocation of rupture to the time, space, and positionalities informing the museum narrative. The paper interrogates the interplay of the survivor’s act of withholding her testimony, the curatorial decision to represent the absence that followed on the withholding, and the disruption to the museum narrative that the withholding prompts. By exploring the withheld testimony as a speaking silence, visible emptiness, and present absence, the paper offers a rethinking of model victimhood under the comfort women system.
The aim of this study was to explore the perspectives of older medicinal cannabis consumers and those advising them on older Canadians’ experiences accessing cannabis and information about it, as well as how stigma may influence their experiences. A concurrent triangulation mixed methods design was used. The design was qualitatively driven and involved conducting semi-structured interviews with older adults and advisors and developing a survey for older adults. We used a Qualitative Descriptive approach for the analysis of qualitative data and descriptive statistics for quantitative survey data. Findings demonstrate that many older adults are accessing information about cannabis for medical purposes from retailers, either because they are reticent to talk to their healthcare professionals or were rebuffed when bringing up the subject. We recommend cannabis education be required for healthcare professionals working with older persons and that future research examines their perspectives on medicinal cannabis and older adults.
Cognitive–behavioural therapy (CBT) has been widely used for a broad range of mental health problems for several decades and has been researched extensively. Its techniques are relatively easy to learn and follow in treatment protocols. Many new CBT-based psychotherapies have been developed that go further than traditional CBT, some specifically addressing personality disorders. These so-called third-wave approaches target emotional responses to situations by using strategies such as mindfulness exercises and acceptance of unpleasant thoughts and feelings (observing thoughts as ‘from afar’). In this article, we discuss the historical context of these therapies, dissect common and specific factors in some treatment modalities often used to treat personality disorders, and suggest potential future directions for research and treatment.
We study numerically the flow around a spherical droplet set fixed in a linear shear flow with moderate shear rates ($Sr\leq 0.5$, $Sr$ being the ratio between the velocity difference across the drop and the relative velocity) over a wide range of external Reynolds numbers ($0.1<{{Re}}\leq 250$, ${{Re}}$ based on the slip velocity and the viscosity of the external fluid) and drop-to-fluid viscosity ratios ($0.01\leq \mu ^\ast \leq 100$). The flow structure, the vorticity field and their intrinsic connection with the lift force are analysed. Specifically, the results on lift force are compared with the low-${{Re}}$ solution derived for droplets of arbitrary $\mu ^\ast$, as well as prior data at finite ${{Re}}$ available in both the clean-bubble limit ($\mu ^\ast \to 0$) and the solid-sphere limit ($\mu ^\ast \to \infty$). Notably, at ${{Re}}=O(100)$, the lift force exhibits a non-monotonic transition from $\mu ^\ast \to 0$ to $\mu ^\ast \to \infty$, peaking at $\mu ^\ast \approx 1$. This behaviour is related to an internal three-dimensional flow bifurcation also occurring under uniform-flow conditions, which makes the flow to evolve from axisymmetric to biplanar symmetric. This flow bifurcation occurs at low-but-finite $\mu ^\ast$ when the internal Reynolds number (${{Re}}^i$, based on the viscosity of the internal fluid) exceeds approximately 300. In the presence of shear, the corresponding imperfect bifurcation enhances the extensional rate of the flow in the wake. Consequently, the streamwise vortices generated behind the droplet can be more intense compared with those behind a clean bubble. Given the close relation between the lift and these vortices, a droplet with ${{Re}}=O(100)$ and $\mu ^\ast \approx 1$ typically experiences a greater lift force than that in the inviscid limit.
In this manuscript, we discuss a systematic approach that healthcare facilities can adopt to prepare to identify, confirm, and safely manage highly pathogenic avian influenza in the healthcare setting.
In the aftermath of the 2022 Pakistan flooding, disaster management faced critical challenges, particularly in mental health support. This study analyzed an incident where eighteen internally displaced individuals lost their lives in a bus fire. The current approach involves a comprehensive analysis of the incident, exploring the difficulties encountered in managing relief efforts, and providing mental health support. The study aims were to evaluate existing mental health support mechanisms, to identify challenges in disaster management, and to propose recommendations for future preparedness. Recommendations include enhancing disaster response training, integrating mental health services into primary health care, and prioritizing community resilience. These insights contribute to a deeper understanding of disaster management in resource-constrained regions.