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.
Quasi-Keplerian flow, a special regime of Taylor–Couette co-rotating flow, is of great astrophysical interest for studying angular momentum transport in accretion disks. The well-known magnetorotational instability (MRI) successfully explains the flow instability and generation of turbulence in certain accretion disks, but fails to account for these phenomena in protoplanetary disks where magnetic effects are negligible. Given the intrinsic decrease of the temperature in these disks, we examine the effect of radial thermal stratification on three-dimensional global disturbances in linearised quasi-Keplerian flows under radial gravitational acceleration mimicking stellar gravity. Our results show a thermo-hydrodynamic linear instability for both axisymmetric and non-axisymmetric modes across a broad parameter space of the thermally stratified quasi-Keplerian flow. Generally, a decreasing Richardson or Prandtl number stabilises the flow, while a reduced radius ratio destabilises it. This work also provides a quantitative characterisation of the instability. At low Prandtl numbers $Pr$, we observe a scaling relation of the linear critical Taylor number $Ta_c\propto Pr^{-6/5}$. Extrapolating the observed scaling to high $Ta$ and low $Pr$ may suggest the relevance of the instability to accretion disks. Moreover, even slight thermal stratification, characterised by a low Richardson number, can trigger the flow instability with a small axial wavelength. These findings are qualitatively consistent with the results from a traditional local stability analysis based on short wave approximations. Our study refines the thermally induced linearly unstable transition route in protoplanetary disks to explain angular momentum transport in dead zones where MRI is ineffective.
In addition to representing a main source of data in linguistic research, example sentences are a core vehicle for linguists in teaching a wide range of phenomena to our students. However, the content of these sentences often reflects the biases of the researchers who construct them: referents are typically given Anglocentric proper names like John and Mary, reflecting (at least implicitly) dominant white culture and conformity to heteronormative gender roles. To support linguists in shifting these practices, we present the Diverse Names Database, a database of 78 names from a variety of languages and cultures, confirmed with native speakers. We outline the goals for the project, introduce our process of developing and adjusting the design, and present some additional issues and reflections for consideration, such as how to use the database as one component of an affirming, anti-racist, and gender-equitable linguistics pedagogy. We aim to generate meta-level discussions about disciplinary conventions and canons, and to challenge the idea that underlying linguistic structures are, or should be, the only things of relevance when constructing example sentences. How we teach linguistics is part of how we practise it, and how we do both matters to the composition and direction of the field.
Analytic Theology and the Academic Study of Religion aims to explain analytic theology to other theologians, and to scholars of religion, and to explain those other fields to analytic theologians. The book defends analytic theology from some common criticisms, but also argues that analytic theologians have much to learn from other forms of inquiry. Analytic theology is a legitimate form of theology, and a legitimate form of academic inquiry, and it can be a valuable conversation partner within the wider religious studies academy. I aim to articulate an attractive vision of analytic theology, foster a more fruitful inter-disciplinary conversation, and enable scholars across the religious studies academy to understand one another better. Analytic theology can flourish in the secular academy, and flourish as authentically Christian theology.
Early childhood growth is associated with cognitive function. However, the independent associations of fat mass (FM) and fat-free mass (FFM) with cognitive function are not well understood. We investigated associations of FM and FFM at birth and 0–5 years accretion with cognitive function at 10 years. Healthy-term newborns were enrolled in this cohort. FM and FFM were measured at birth, 1·5, 2·5, 3·5, 4·5 and 6 months and 4 and 5 years. Cognitive function was assessed using the Peabody Picture Vocabulary Test (PPVT) at 10 years. FM and FFM accretions were computed using statistically independent conditional accretion from 0 to 3 months, 3 to 6 months, 6 months to 4 years and 4 to 5 years. Multiple linear regression was used to assess associations. At the 10-year follow-up, we assessed 318 children with a mean (sd) age of 9·8 (1·0) years. A 1 sd higher birth FFM was associated with a 0·14 sd (95 % CI 0·01, 0·28) higher PPVT at 10 years. FFM accretion from 0 to 3 and 3 to 6 months was associated with PPVT at 10 years: β = 0·5 sd (95 % CI 0·08, 0·93) and β = −0·48 sd (95 % CI −0·90, −0·07, respectively. FFM accretion after 6 months showed no association with PPVT. Neither FM at birth nor 0–5 years accretion showed an association with PPVT. Overall, birth FFM, but not FM, was associated with cognitive function at 10 years, while the association of FFM accretion and cognitive function varied across distinct developmental stages in infancy. The mechanisms underlying this varying association between body composition and cognitive function need further investigation.
A routine chemical procedure was developed at the Ede Hertelendi Laboratory of Environmental Studies (HEKAL), in Debrecen which can measure the dissolved organic radiocarbon content of groundwater as well as the inorganic and total fraction. The typical background of this non-purgeable dissolved organic radiocarbon preparation is 0.73 ± 0.14 percent modern carbon (pMC), using a carbon contamination correction on fossil dissolved material (potassium hydrogen phthalate) samples.
where $n\geq3$, $0 \lt p\leq1$. By establishing an equivalent integral equation, we give a lower bound of the Kelvin transformation $\bar{u}$. Then, by constructing a new comparison function, we apply the maximum principle based on comparisons and the method of moving planes to obtain that u only depends on xn. Based on this, we prove the non-existence of non-negative solutions.
I survey my career in philosophy, which encompasses 44 years of teaching in Halifax, but begins in London, England with a thesis on self-deception. I describe a practice of using works of literature as a guide to conceptual analysis, and pause in Vienna to translate On Last Things (Weininger, 2001). A line of Wittgenstein's is the basis for reflections on the concept of a Last Judgement. I discuss in some detail a paper of mine for the Atlantic Region Philosophers’ Association in 2018, “One Last Thing,” which takes as its basis The Sense of an Ending, a novel by Julian Barnes. I conclude with some claims about Wittgenstein's relation to religion. I add an Appendix, in which I comment briefly on each of the other articles that make up this symposium.
Individuals may experience health issues attributable to environmental pollution, sedentary lifestyles, and unhealthy dietary habits. In response, numerous non-pharmaceutical treatments and techniques have emerged, with therapy mud being one such approach. The primary aim of this research was to analyze the chemical and mineralogical compositions of peloids obtained from six salt lakes: Taigan (LI), Duruu (LII), Khadaasan (LIII), Ikhes (LIV), Tonkhil (LV), and Khulmaa (LVI) in the Gobi-Altai province of Mongolia. Sample analyses involved X-ray diffraction for mineralogical assessment and inductively coupled plasma-mass spectrometry (Agilent Technologies 7800 series in Canada) for determining the chemical composition of the solid phase. Among essential macro- and microelements, Mg, Cа, Na, K, Sr, Ga, Mo, and Se had been leached from peloid to artificial sweat. Sn (0.01 μg g–1) at LIV and LVI lakes and Cu (0.01 μg g–1) at LV lake transferred from peloids to sweat, but no mobility of these elements in other peloids was detected. Li (0.02–0.04 μg g–1) was adsorbed from the sweat to potential peloids in LV, LIV, LIII, and LI lakes, while As (0.04–0.09 μg g–1) leached from peloids to sweat in all lakes except for LII. Zn (0.01 μg g–1) and Cr (0.04 μg g–1) transferred from the sweat to peloids in all lakes. Macroelements (Na, K, Ca, and Mg) and microelements (Mo, Se), which are essential for the human body, leached from the peloid to sweat. However, the mobility of toxic elements was minimal. Among micro-elements, the transition of Sr occurred the most, which can be explained by the Sr content in the peloid.
School food has a major influence on children’s diet quality and has the potential to reduce diet inequalities and non-communicable disease risk. Funded by the UK Prevention Research Partnership, we have established a UK school food system network. The overarching aim was to build a community to work towards a more health-promoting food and nutrition system in UK schools. The network has brought together a team from a range of disciplines, while the inclusion of non-academic users and other stakeholders, such as pupils and parents, has allowed the co-development of research priorities and questions. This network has used a combination of workshops, working groups and pump-priming projects to explore the school food system, as well as creating a systems map of the UK school food system and conducting network analysis of the newly established network. Through understanding the current food system and building network expertise, we hope to advance research and policy around food in schools. Further funding has been achieved based on these findings, working in partnership with policymakers and schools, while a Nutrition Society Special Interest Group has been established to ensure maximum engagement and future sustainability of the network. This review will describe the key findings and progress to date based on the work of the network, as well as a summary of the current literature, identification of knowledge gaps and areas of debate, according to key elements of the school food system.
This article is inspired by two of Steven Burns's many philosophical interests — self-deception and Wittgenstein — as well as by a wariness that we share of the analytic-continental divide in contemporary philosophy. I argue here that, despite obvious differences of temperament and concern, Sartre and Wittgenstein share a scepticism about the “epistemic model” of first-person authority. This shared scepticism emerges in a striking way in their challenges to the idea that psychological phenomena should be understood on the model of objects in physical space. Wittgenstein's scepticism is more thorough-going, but emphasizing the similarity allows us to see Sartre as making an important contribution to our understanding of first-person authority, even if we are wary of the voluntarism of his approach.
This article is an appreciative exegesis of Steven Burns's article “If a Lion Could Talk.” In his essay, Burns clarifies Ludwig Wittgenstein's enigmatic remark “If a lion could talk, we wouldn't be able to understand him” by locating it within the broader context of Wittgenstein's work in the philosophy of psychology. We read Burns's interpretation of the remark as opening core Wittgensteinian issues of meaning and (mis)understanding, and we situate it within the context of the work of Burns's teacher, Peter Winch. Our discussion is a close exegesis of the immediate content of the lion remark and it highlights connections to Wittgenstein's remarks on James George Frazer's The Golden Bough. We show how Burns and Winch employ Wittgenstein's methods of dissolving philosophical puzzles by drawing attention to intermediate familiar cases. We conclude with some impressionistic remarks about Socrates in a short discussion of the difficulty of the philosophical technique and activity Burns demonstrates and recommends.
We study the effect of acceleration and deceleration on the stability of channel flows. To do so, we derive an exact solution for laminar profiles of channel flows with an arbitrary, time-varying wall motion and pressure gradient. This solution then allows us to investigate the stability of any unsteady channel flow. In particular, we restrict our investigation to the non-normal growth of perturbations about time-varying base flows with exponentially decaying acceleration and deceleration, with comparisons to growth about a constant base flow (i.e. the time-invariant simple shear or parabolic profile). We apply this acceleration and deceleration through the velocity of the walls and through the flow rate. For accelerating base flows, perturbations never grow larger than perturbations about a constant base flow, while decelerating flows show massive amplification of perturbations – at a Reynolds number of $500$, properly timed perturbations about the decelerating base flow grow $ {O}(10^5)$ times larger than perturbations grow about a constant base flow. This amplification increases as we raise the rate of deceleration and the Reynolds number. We find that this amplification arises due to a transition from spanwise perturbations leading to the largest amplification to streamwise perturbations leading to the largest amplification that only occurs in the decelerating base flow. By evolving the optimal perturbations through the linearized equations of motion, we reveal that the decelerating base flow achieves this massive amplification through the Orr mechanism, or the down-gradient Reynolds stress mechanism, which accelerating and constant base flows cannot maintain.
With the rapid increase in the use of drones in various applications, including commercial and governmental, and the increasing probability of communication failures and contingencies, research becomes critical to ensure the safety and efficiency of their operations. The aim of this research is to develop adaptive drone flight control algorithms capable of operating effectively under conditions of limited communication and incomplete information to ensure reliable and safe autonomous operation of these systems. The applied methods include computer modelling and simulation, analytical, statistical, functional, deductive and descriptive methods. The study found that the use of performance evaluation methods for complex systems enables the identification of safety and performance criteria for drones, and drone flight control provides basic principles and methods that can be adapted for drones, including autopiloting and navigation. In addition, analyses of satellite communication and navigation prove the need to consider the limitations of this technology when developing drone control algorithms. The combination of these techniques allows for more robust and adaptive drone control systems that can function effectively in complex environments such as communication limitations and incomplete information. Additionally, it was found that the integration of adaptive control algorithms based on these methods allows drones to effectively adapt to variable environmental conditions and make decisions quickly even when communication is lost or information is limited.
Inspired by Adler’s idea on VC minimal theories [1], we introduce VC-minimal complexity. We show that for any $N\in \mathbb {N}^{>0}$, there is $k_N>0$ such that for any finite bipartite graph $(X,Y;E)$ with VC-minimal complexity $< N$, there exist $X'\subseteq X$, $Y'\subseteq Y$ with $|X'|\geq k_N |X|$, $|Y'|\geq k_N |Y|$ such that $X'\times Y' \subseteq E$ or $X'\times Y'\cap E=\emptyset $.
The present study aims to examine the temporal linear stability analysis of isothermal plane Couette flow over a porous layer using the two-domain approach. The flow in the porous layer is described by the unsteady Darcy–Brinkman equations, whereas it is characterised by the Navier–Stokes equations in the fluid layer. In contrast to the Darcy model, it is observed that the isothermal plane Couette flow becomes unstable for such a superposed system on the inclusion of the Brinkman term. From the stability analysis, the two-dimensional mode is found to be least stable, and two modes of instability, namely porous mode and mixed mode are obtained under the consideration of the Darcy–Brinkman model along with advection term (DBA model). For Darcy number $(\delta )=0.01$, depending on the value of the stress-jump coefficient, mixed mode controls the instability of the system at small values of depth ratio $(\hat {d})$, and it disappears for relatively high values of $\hat {d}$, where the porous mode dominates. In addition, it has been observed that when $\hat {d}=0.1$, the critical mode of instability is found to be mixed for $\delta >0.02$ and porous for $\delta \le 0.02$. The stress-jump coefficient destabilises the flow in terms of energy production through perturbed stresses at the interface. As observed in the case of isothermal plane Poiseuille flow studied by Chang, Chen & Straughan (J. Fluid Mech., vol. 564, 2006, pp. 287–303), here also depth ratio (Darcy number) stabilises (destabilises) the flow. However, this characteristic does not remain valid when the advection term is eliminated from the considered momentum equation. For a certain range of $\hat {d} (\delta )$, the destabilising (stabilising) characteristic of the respective parameters are encountered when the fluid mode of instability prevails.
Paul's epistemology was famously mapped onto his eschatology by J. Louis Martyn, but it must be mapped also onto his ecclesiology. For Paul, knowing is bound always and indissolubly to living with others. To understand how Paul would have us know things, then, we must focus not on knowledge as such, but on epistemic practices in ecclesial communities. Whereas the Corinthians’ use of wisdom and knowledge made for fragmentation and dissolution in the body of Christ (1 Cor 1–4; 8–10), Paul would have practices with knowledge instantiate communion and care for one another, as is proper for Christ's body. Integral to theological knowing is a sense of what and whom theology is for, a sense being critically explored in recent evaluations of theological education.