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This work experimentally explores the alignment of the vorticity vector and the strain-rate tensor eigenvectors at locations of extreme upscale and downscale energy transfer. We show that the turbulent von Kármán flow displays vorticity–strain alignment behaviour across a large range of Reynolds numbers, which is very similar to previous studies on homogeneous, isotropic turbulence. We observe that this behaviour is amplified for the largest downscale energy transfer events, which tend to be associated with sheet-like geometries. These events are also shown to have characteristics previously associated with high flow field nonlinearity and singularities. In contrast, the largest upscale energy transfer events display very different structures which showcase a strong preference for vortex compression. Notably, in both cases we find that these trends are strengthened as the probed scales approach the Kolmogorov scale. We then show further evidence for the argument that strain self-amplification is the most salient feature in characterising the cascade direction. Finally, we identify possible invariant behaviour for the largest energy transfer events, even at scales near the Kolmogorov scale.
In this paper, we show that the diffraction of the primes is absolutely continuous, showing no bright spots (Bragg peaks). We introduce the notion of counting diffraction, extending the classical notion of (density) diffraction to sets of density zero. We develop the counting diffraction theory and give many examples of sets of zero density of all possible spectral types.
Increasing penetration of variable and intermittent renewable energy resources on the energy grid poses a challenge for reliable and efficient grid operation, necessitating the development of algorithms that are robust to this uncertainty. However, standard algorithms incorporating uncertainty for generation dispatch are computationally intractable when costs are nonconvex, and machine learning-based approaches lack worst-case guarantees on their performance. In this work, we propose a learning-augmented algorithm, RobustML, that exploits the good average-case performance of a machine-learned algorithm for minimizing dispatch and ramping costs of dispatchable generation resources while providing provable worst-case guarantees on cost. We evaluate the algorithm on a realistic model of a combined cycle cogeneration plant, where it exhibits robustness to distribution shift while enabling improved efficiency as renewables penetration increases.
Objectives/Goals: Transmission-blocking vaccines hold promise for malaria elimination by reducing community transmission. But a major challenge that limits the development of efficacious vaccines is the vast parasite’s genetic diversity. This work aims to assess the genetic diversity of the Pfs25 vaccine candidate in complex infections across African countries. Methods/Study Population: We employed next-generation amplicon deep sequencing to identify nonsynonymous single nucleotide polymorphisms (SNPs) in 194 Plasmodium falciparum samples from four endemic African countries: Senegal, Tanzania, Ghana, and Burkina Faso. The individuals aged between 1 and 74 years, but most of them ranged from 1 to 19 years, and all presented symptomatic P. falciparum infection. The genome amplicon sequencing was analyzed using Geneious software and P. falciparum 3D7 as a reference. The SPNs were called with a minimum coverage of 500bp, and for this work, we used a very sensitive threshold of 1% variant frequency to determine the frequency of SNPs. The identified SNPs were threaded to the crystal structure of the Pfs25 protein, which allowed us to predict the impact of the novel SNP in the protein or antibody binding. Results/Anticipated Results: We identified 26 SNPs including 24 novel variants, and assessed their population prevalence and variant frequency in complex infections. Notably, five variants were detected in multiple samples (L63V, V143I, S39G, L63P, and E59G), while the remaining 21 were rare variants found in individual samples. Analysis of country-specific prevalence showed varying proportions of mutant alleles, with Ghana exhibiting the highest prevalence (44.6%), followed by Tanzania (12%), Senegal (11.8%), and Burkina Faso (2.7%). Moreover, we categorized SNPs based on their frequency, identifying dominant variants (>25%), and rare variants (Discussion/Significance of Impact: We identified additional SNPs in the Pfs25 gene beyond those previously reported. However, the majority of these newly discovered display low variant frequency and population prevalence. Further research exploring the functional implications of these variations will be important to elucidate their role in malaria transmission.
In this article, it is shown that the lattice of C$^*$-covers of an operator algebra does not contain enough information to distinguish operator algebras up to completely isometric isomorphism. In addition, four natural equivalences of the lattice of C$^*$-covers are developed and proven to be distinct. The lattice of C$^*$-covers of direct sums and tensor products are studied. Along the way key examples are found of operator algebras, each of which generates exactly n C$^*$-algebras up to $*$-isomorphism, and a simple operator algebra that is not similar to a C$^*$-algebra.
This chapter summarizes Neurath’s manifold achievements before 1934, when he was forced to leave Vienna. Neurath managed to fit several careers into one, relatively short lifetime, being active in education, urbanism, economic planning, museology, graphic design, and philosophy. After an account of his student years, we document his participation in the proto-Vienna Circle, his theories of war economy, and his attempt at socialization in revolutionary Bavaria. Back in Vienna, Neurath became director of the Austrian settlers’ organization, involved in architectural planning, and founded the Social and Economic Museum, where a team of collaborators developed the Vienna Method of Pictorial Statistics (later known as Isotype). Neurath was also a founding member of the Vienna Circle, alongside Moritz Schlick, Rudolf Carnap, and Hans Hahn. Neurath was a dissenting voice from the Circle’s prevalent adulation for Wittgenstein.
Since the early 1930s, a broad acceptance of the need for social planning had been growing in Britain. Neurath naturally became involved in debates on this matter, not only with British and American scholars (C. H. Waddington and James Burnham) but with fellow Central European émigrés in the UK, Karl Mannheim and Friedrich Hayek. Neurath and Mannheim concurred on the possibility of ‘planning for freedom’, whereas Hayek feared that any socialist planning would lead inevitably to totalitarianism. Neurath took issue with this, not least in his reading of Hayek’s The Road to Serfdom, which can be reconstructed from Neurath’s copious notes in his own copy. Neurath’s ideas of the 1920s for a socialized ‘economy in kind’ were moderated by his situation in Britain, with its democratic ‘muddle’ of the 1940s. By contextualizing Neurath’s views in relation to other prominent figures of the era, we point out what made him unique among them.
This chapter examines first the gradual infiltration of logical empiricism into British philosophy during the 1930s, mainly through lectures by Schlick and Carnap, and not necessarily in accordance with Neurath’s ideas. L. Susan Stebbing played an important role as mediator, although she reflected on differences between the Viennese and the British analytical approaches. A. J. Ayer’s bestselling book Language, Truth, and Logic prepared the ground to some extent, but, by the time Neurath arrived to give a series of lectures at Oxford University, philosophers were mostly absent serving in the war. Neurath’s lectures are reconstructed from his notes, and the changes and developments in his philosophy of science are examined, also with reference to his monograph Foundations of the Social Sciences. We show that Neurath’s late work adapted to British sociological and anthropological thinking, often at the cost of bitter debates with old friends, such as Rudolf Carnap.
Neurath’s first port of exile after the fascist takeover in Austria was the Netherlands. With the aid of existing connections there, he set up the International Foundation for Visual Education in The Hague, providing an official haven for the work of the Social and Economic Museum. It also acted as a base for the International Institute for the Unity of Science, through which Neurath organized its congresses during the 1930s. Neurath’s Dutch period was marked by increasing contacts with England and the USA: he wrote books in C. K. Ogden’s Basic English and for New York publisher Knopf; he also became editor-in-chief of the International Encyclopedia of Unified Science. On several visits to the USA, he secured high-profile contracts for Isotype work, while also exploring the possibility of a foothold in Britain.
This chapter describes in detail Neurath’s adventurous escape from The Hague with other refugees on a small boat that was intercepted by a British warship. He and his partner Marie Reidemeister were then interned as enemy aliens on the Isle of Man, due to the encroaching threat of German invasion. The internment camps were a microcosm of Central European culture, and Neurath participated in the ‘popular university’ organized by internees of his camp. The correspondence between Neurath and Reidemeister (in separate camps) reveals their optimistic determination to continue working together, as well as Neurath’s predisposal to British culture. The Society for the Protection of Science and Learning campaigned for their release but, despite intervention from Albert Einstein, their case was not simple.
Neurath’s interest in international languages led to him developing an alternative to verbal language, the pictorial technique of Isotype. This chapter documents significant wartime projects using this method, including animated sections for documentary films and charts for publications produced by pioneering ‘book packager’ Adprint. The Isotype Institute contributed to the book on Lancelot Hogben’s own invented language Interglossa. Neurath also explored the establishment of a research centre for visual education in consultation with Hogben, Julian Huxley, and US ambassador J. G. Winant. His last book project titled ‘Visual Education’ was written for Karl Mannheim’s ‘International Library of Sociology and Social Reconstruction’, although it remained unpublished until long after his death. It was a wide-ranging reflection on the acquisition of knowledge and its social determinacy.
This chapter sets the stage for the volume, describing an approach to Otto Neurath’s last years that weaves together biographical, historical, and philosophical strands. Neurath can also be examined from the angle of ‘exile studies’, enthusiastically adapting to British life and making contributions to philosophy, economics, and visual education that were ahead of his time. The themes of planning and education are introduced as narrative hooks to understand Neurath’s late work.
The last major chapter of the book reflects on the question of ‘happiness’ as discussed by Popper, Hayek, and Neurath, but also presents a case study of how Neurath not only theorized on such matters but also sought to make a practical difference by collaboration in planning projects. He became a consultant for the redevelopment of Bilston, a small town blighted by the legacy of the Industrial Revolution. In discussion with town councillors and architects, he steered plans by taking into account the needs of residents, seeking to represent those whose voice was generally not heard. This finally led to Neurath being interviewed in the mainstream media, marking acceptance and respect for Neurath in British culture. He did not want to use his broad learning to set himself apart as an intellectual but instead to articulate the needs of ordinary people.
Chapter 4 is a detailed description of Neurath’s adaptation to British life and professional re-establishment, mainly in the field of visual education. The Isotype Institute was established in Oxford, and this method was rapidly taken up by documentarist Paul Rotha for use in films for the Ministry of Information. The Neuraths also collaborated in producing books of ‘soft propaganda’ about Britain and its allies, and made a pioneering visualization of the Beveridge Plan of social insurance. Neurath attempted to reconstruct a scholarly environment for himself, and was keen to embrace the English language. He was much in demand as a lecturer and consultant, speaking ‘broken English fluently’. He was supportive of fellow émigrés but wary of Austrian exile politics. Inadvertently, he came into contact with some people later revealed to have been Soviet spies.