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.
The dynamics of suspensions of particles has been an active area of research since Einstein first calculated the leading-order correction to the viscosity of a suspension of spherical particles (Einstein, Proc. R. Soc., vol. A102, 1906, pp. 161–179). Since then, researchers have strived to develop an accurate description of the behaviours of suspensions that goes beyond just leading order in the particle volume fraction. Here, we consider the low-Reynolds-number behaviour of a suspension of spherical particles. Working from the Green's functions for the flow due to a single particle, we derive a continuum-level description of the dynamics of suspensions. Our analysis corrects an error in the derivation of these equations in the work of Jackson (Chem. Engng Sci., vol. 52, 1997, pp. 2457–2469) and leads to stable equations of motion for the particles and fluid. In addition, our resulting equations naturally give the sedimentation speed for suspended particles and correct a separate error in the calculation by Batchelor (J. Fluid Mech., vol. 52, 1972, pp. 245–268). Using the pair-correlation function for hard spheres, we are able to compute the sedimentation speed out to seventh order in the volume fraction, which agrees with experimental data up to 30 %–35 %, and also get higher-order corrections to the suspension viscosity, which agree with experiments up to $\sim$15 %. Then, using the pair distribution for spheres in shear flow, we find alterations to both the first and second normal stresses.
A new compact wideband filtering balun based on substrate-integrated suspended line technology is presented in this brief. The proposed device is composed of a λg/4 suspended stripline open-circuited stub, a λg/2 suspended stripline resonator, and a λg/2 suspended slotline resonator. These striplines and slotline are encapsulated in an electromagnetic (EM) shielding box consisting of air cavity, surrounding substrate layers, and metal layers to achieve EM shielding performance. By properly exciting the suspended stripline and slotline resonators, three transmission poles are generated to achieve high frequency selectively. The intrinsic 180∘ phase difference between the two output ports can be obtained by using the electric field distribution caused by the perpendicular coupling between the suspension stripline and the slotline resonator. The wideband passband is achieved with magnitude balance and out-of-phase properties. To validate our proposal, a wideband filtering balun operating at 2.56 GHz with fractional bandwidth of 65.6% is designed and fabricated.
Purpose in life has been found to decline from middle to later life in several ageing studies. Because the decline has negative impacts on health-related outcomes, it is important to identify factors contributing to purpose in life to enhance wellbeing among the ageing population. This study first examined the role of subjective social economic status (SSES) in the relationship between age and purpose in life. Subsequent analyses estimated whether the construct Artistic Creativity as a Source for Meaning in Life (ACASMIL) played a role in cultivating purpose in life among ageing individuals. Moreover, the analyses determined whether this effect was strengthened by creative self-concept (i.e. self-conviction about personal identity and self-efficacy in the global domain of creativity). Results from a sample of 224 individuals from middle to third age (mean age = 54.08, standard deviation = 10.08, range = 40–84) revealed that the relationship between age and purpose in life was only positive among those with relatively high SSES, controlling for gender and country of residence. Controlling for gender, country of residence, age and SSES, it was found that ACASMIL did not play a mediator role. Moreover, creative self-concept played a moderator role in the relationship between artistic creativity and ACASMIL. However, this moderation effect of creative self-concept was negative. Implications and suggestions for future directions are discussed.
Geriatric depression (GD) is associated with significant medical comorbidity, cognitive impairment, brain atrophy, premature mortality, and suboptimal treatment response. While apathy and anxiety are common comorbidities, resilience is a protective factor. Understanding the relationships between brain morphometry, depression, and resilience in GD could inform clinical treatment. Only few studies have addressed gray matter volume (GMV) associations with mood and resilience.
Participants:
Forty-nine adults aged >60 years (38 women) with major depressive disorder undergoing concurrent antidepressant treatment participated in the study.
Measurements:
Anatomical T1-weighted scans, apathy, anxiety, and resilience data were collected. Freesurfer 6.0 was used to preprocess T1-weighted images and qdec to perform voxel-wise whole-brain analyses. Partial Spearman correlations controlling for age and sex tested the associations between clinical scores, and general linear models identified clusters of associations between GMV and clinical scores, with age and sex as covariates. Cluster correction and Monte-Carlo simulations were applied (corrected alpha = 0.05).
Results:
Greater depression severity was associated with greater anxiety (r = 0.53, p = 0.0001), lower resilience (r = −0.33, p = 0.03), and greater apathy (r = 0.39, p = 0.01). Greater GMV in widespread, partially overlapping clusters across the brain was associated with reduced anxiety and apathy, as well as increased resilience.
Conclusion:
Our results suggest that greater GMV in extended brain regions is a potential marker for resilience in GD, while GMV in more focal and overlapping regions may be markers for depression and anxiety. Interventions focused on improving symptoms in GD may seek to examine their effects on these brain regions.
Isn't there something like an amount and density of horrific suffering whose discovery would make it irrational to think God exists? Use your imagination to think of worlds that are much, much, much worse than you think Earth is when it comes to horrific suffering. Isn't there some conceivable scenario which, if you were in it, would make you say ‘Okay, okay. God doesn't exist, at least in the way we thought God was. We were wrong about that’? Pursuing this question leads to what I call the Problem of Absurd Evil.
A form of Sinology emerged in Vietnam in the early twentieth century during the period of colonial rule as Western learning came to replace the traditional curriculum of the Confucian classics. At first, scholars sought to preserve traditional learning by translating Confucian and Buddhist texts into the Vietnamese vernacular. Then in the 1930s and 1940s, scholars produced works on Chinese history, philosophy, and literature that engaged with the works of modern scholars from China and the West. The development of this body of Sinological scholarship was then disrupted by periods of revolution and war. This article traces the development of Sinology in Vietnam through these periods up to the present.
Helicopter collisions with obstacles are one of the most frequent and most devastating causes of accidents. To avoid these collisions in low-speed operations a “haptic ticker” cue in form of repetitive impulses as a force feedback was designed for an active sidestick. Various design questions were examined in pilot campaigns using a full flight simulator and four test scenarios. As a result, the pilots always knew which distance-based hazard area (green, yellow, red) they were in. Furthermore, the ticker is disruptive and roughly reduces the handling qualities from Level 1 to Level 2. It is therefore primarily activated as a hazard warning and not as a main input to control the distance. As a warning cue the ticker was evaluated as non-disturbing. The force threshold to detect the direction of a tick was determined. With tick strengths above this threshold, the direction is still not recognised at all in around 2% of the ticks. For the remaining ticks, the accuracy with which the direction is recognised is about 15°. In the fourth scenario, obstacles were moved towards the hovering helicopter, potentially forcing a collision. However, with the ticker a collision occurred in less than 4% of the cases, instead of 84% without the ticker. The ticker was rated as very intuitive and worth recommending. When asked how many accidents of this kind could be prevented with this ticker, all five pilots independently estimated 75%.
Let $f(X) \in {\mathbb Z}[X]$ be a polynomial of degree $d \ge 2$ without multiple roots and let ${\mathcal F}(N)$ be the set of Farey fractions of order N. We use bounds for some new character sums and the square-sieve to obtain upper bounds, pointwise and on average, on the number of fields ${\mathbb Q}(\sqrt {f(r)})$ for $r\in {\mathcal F}(N)$, with a given discriminant.
Ventilated cavitating flows are investigated via direct numerical simulations, using a coupled level set and volume of fluid method to capture the interface between the air and water phases. A ventilated disk cavitator is used to create the cavity and is modelled by a sharp-interface immersed boundary method. The simulation data provide a comprehensive description of the two-phase flow and the air leakage and vortex shedding processes in the cavitating flow. The mean velocity of the air phase suggests the existence of three characteristic flow structures, namely the shear layer (SL), recirculating area (RA) and jet layer (JL). The turbulent kinetic energy (TKE) is concentrated in the JL in the closure region, and streamwise turbulent fluctuations dominate transverse fluctuations in both SL and JL. Budget analyses of the TKE show that the production term causes the TKE to increase in the SL due to the high velocity gradients, and decrease in the JL due to streamwise stretching effects. Air leakage and vortex shedding occur periodically in the closure region, and the one-to-one correspondence between these two processes is confirmed by the velocity and volume fluid spectra results, and the autocorrelation function of the air volume fraction. Moreover, the coherent flow structures are analysed using the spectral proper orthogonal decomposition method. We identify several fine coherent structures, including $SL_{KH}$ induced by the Kelvin–Helmholtz instability, $SL_{out}$ associated with large-scale vortex shedding, $SL_{in}$ associated with small-scale vortex shedding, and $SL_{r}$ associated with upstream turbulent convection. The present study complements previous research by providing detailed descriptions of the turbulent motions associated with the violent mixing of air and water, and the complex interactions between different characteristic structures in cavitating flows.
There is a wealth of literature characterizing social difficulties in autism spectrum disorder (ASD). However, little work has replicated longitudinal findings from typical development that adolescent social competence predicts positive adult outcomes in ASD. The current study examined social competence trajectories from 2 to 26 and the utility of three social competence measures collected in adolescence in predicting work, residential status, friendship, and romantic outcomes in a longitudinal cohort (n = 253) of ASD. Using group-based trajectory modeling, we identified two patterns of social competence development: a low trajectory characterized by slow linear gains throughout childhood and plateauing in adulthood, and a high trajectory characterized by steeper linear gains in childhood followed by decline in adulthood. Regression models indicated one social competence measure, Vineland Social-AE scores, significantly predicted employment, residential status, and friendships in adulthood. One other social competence measure, SSQ total scores, also significantly predicted friendship in adulthood. Only nonverbal IQ at 9 predicted the likelihood of having ever had a romantic relationship. These findings highlight the role of social competence in both atypical and typical development and suggest the social impairments associated with ASD do not necessarily impact all realms of social functioning equally.
Direct numerical simulations of the turbulent flow in a channel are conducted up to $Re_{\tau }=1000$ to examine the influence of the friction Reynolds number on the translational and angular velocities of inertial, prolate ellipsoids. The quadrant distribution of the turbulent events seen by the particles is not significantly affected by the value of $Re_{\tau }$, but subtle modifications take place, depending on the position in the channel and on the particle relaxation time. Overall, the influence of $Re_{\tau }$ on the first and second statistical moments of the ellipsoids translational velocity is the same as that observed for the fluid velocity. The weak dependence of these statistics to the particle shape previously observed at low Reynolds number remains at higher values of $Re_{\tau }$. Similarly, the mean and root mean square (r.m.s.) of the angular velocity of the fluid seen by the particles weakly depend on particle shape and they have the same dependence to $Re_{\tau }$ as the angular velocity statistics of the carrier fluid. Particle angular velocity statistics are more strongly affected by the flow Reynolds number due to the evolution of the complex shape and inertia dependent rotation orbits with $Re_{\tau }$. In the near-wall region the average angular velocity of weakly inertial ellipsoids increases with $Re_{\tau }$ due to their stronger alignment with the mean fluid vorticity. Furthermore, the r.m.s. of the wall-normal component of the angular velocity of more inertial ellipsoids increases with $Re_{\tau }$ owing to the larger fluctuations of the angle between the particle major axis and the velocity-gradient plane.
The intersection of nationalism and inequality is undoubtedly gaining interest in current debates in nationalism studies. The effects of economic inequalities on nationalist politics are the most researched area; however, there are other ways to explore the relationship between nationalism and inequality. Focusing on economic and political aspects of inequality this state-of-the-field article offers an overview of existing research on the relationship between inequality and nationalism in various areas of nationalism studies, ranging from nationalist politics to exploring the symbolic construction of nationhood. Following the inequality scholars, we highlight the growing importance of capital accumulation and emphasize the spatial aspect of it. We argue that while being largely overlooked, the role of territory—and territorial politics more broadly—becomes crucial for the understanding of the intersection of nationalism and inequality today. Overall, we show that it is necessary for nationalism studies scholars to engage in contemporary literature on inequality and acknowledge the wider implications of growing inequality to various manifestations of nationalism.
In a recent article in Religious Studies, Ada Agada argues that the problem of evil is relevant not only to those who consider God to hold the Omni-properties but also to those who understand God as a limited deity. He rightly points out that the limited-God literature in the African philosophy of religion has neglected to address the problem of evil by too quickly dismissing it. Agada then argues that the reason why the problem of evil is philosophically relevant for the limited-God view is that He, as the creator, has sufficient powers to address evil and, thereby, moral responsibility regarding the evil in the world. In this reply, I uphold that although Agada is correct to affirm that the problem of evil is relevant for the limited-God view, he is mistaken to contend that the reason is that God is the creator. I contest this view and argue that Agada has not given enough reasons to believe that God has moral responsibility over evil in the world. However, I illuminate how Agada can develop this argument in the future.
Previously published guidelines have provided comprehensive recommendations for detecting and preventing healthcare-associated infections (HAIs). The intent of this document is to highlight practical recommendations in a concise format designed to assist acute-care hospitals in implementing and prioritizing efforts to prevent methicillin-resistant Staphylococcus aureus (MRSA) transmission and infection. This document updates the “Strategies to Prevent Methicillin-Resistant Staphylococcus aureus Transmission and Infection in Acute Care Hospitals” published in 2014.1 This expert guidance document is sponsored by the Society for Healthcare Epidemiology of America (SHEA). It is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America (IDSA), the Association for Professionals in Infection Control and Epidemiology (APIC), the American Hospital Association (AHA), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise.
Este estudio contribuye al entendimiento de la interrelación entre cambio ambiental, modificaciones en las estrategias de subsistencia y movilidad de grupos cazadores-recolectores, y la incorporación de nuevas tecnologías de captura y procesamiento de recursos durante el Holoceno tardío en el centro-oeste de Santa Cruz, Patagonia meridional, Argentina. Se presentan valores inéditos de δ13C sobre apatita y valores de δ15N y δ13C sobre colágeno de 42 individuos recuperados en estructuras de entierros con diferentes cronologías. Se utilizó el concepto de nicho isotópico para entender las continuidades y/o cambios de la dieta cazadora-recolectora. Se evaluó si hubo variaciones temporales y sexuales entre los nichos isotópicos de los individuos con patrones diferentes de organización social y económica en momentos previos y posteriores a los 900 años aP. Los resultados indican cambios en la dieta en los últimos 1.000 años, lo que se plasmó en valores más bajos en δ13Capa de los individuos enterrados en los chenques tardíos y, en particular, en las mujeres. De esta manera, la información paleodietaria apoya la hipótesis de modificaciones en el nicho isotópico a través del tiempo.