bluuebunny/crossref_metadata_2025_split huggingface dataset:
Symmetric designs
Authors: Anderson Ian 
Published: November 2023

Abstract
In this chapter we look at symmetric designs, studying in particular Hadamard designs and finite projective planes. These are the ‘extreme’ symmetric designs in the sense of Theorem 3.1.2 below. For example, a (7,3,1) design is both a finite projective plane of order 2 and a Hadamard design of order 2; the lower and upper bounds of Theorem 3.1.2 coincide when n = 2. The reason for the name ‘Hadamard design’ is explained in the next section.
Structures of nucleic acid triplexes
Authors: Wang Edmond , Feigon Juli 
Published: November 2023

Abstract
During the past 10 years, interest in triple-stranded nucleic acids (triplexes) has been considerable. Hundreds of research papers have been published on various aspects of triple-stranded nucleic acids: these include studies ranging from stability and sequence requirements to potential biological roles and pharmaceutical uses. Although the idea of triple-stranded nucleic acids (triplexes) seems contemporary, it actually dates back to 1953 when Linus Pauling proposed a three-stranded model for standard DNA that placed the phosphate backbones in the centre of a helix and the bases facing outwards (1,2). This model was considered unlikely for electrostatic reasons, and the correct double-stranded structure was proposed by Watson and Crick (3).
Noncommutative Differential Geometry and the Structure of Space—Time
Authors: Cannes Alain 
Published: November 2023

Abstract
One of the original motivations of noncommutative geometry is to apply geo metric ideas and concepts to spaces which are intractable if considered from the usual set-theoretic ideas of Riemannian geometry. Among the first examples of such spaces are the leaf spaces of foliations or the duals of noncommutative discrete groups. A more recent example comes from number theory and the Riemann zeta function, and allows us to give a spectral interpretation of the critical zeros of that function. One of the difficulties of the subject is to acquire an intuitive idea of the nature of noncommutative spaces. I remember with emotion the talk given by Roger Penrose a few years ago in which he exhibited, showing the superposition of two transparencies representing Penrose tilings, the quantum nature of the space of Penrose tilings of the plane. The point is that even though the space of such tilings is uncountable, any two tilings can be superposed exactly on arbitrarily large portions, thus exhibiting fluctuations very reminiscent of quantum mechanics. The space of Penrose tilings is a prototype of a noncommutative space and it gives me great pleasure to expound the latest developments of noncommutative geometry on the occasion of his birthday.
Space from the Point of View of Loop Groups
Authors: Segal Graeme 
Published: November 2023

Abstract
I feel honoured to be speaking at this meeting to celebrate Roger Penrose’s birthday. I am sure that for all of us Penrose stands out among the people who have thought most deeply and most ingeniously about the nature of space and time. What I am going to talk about is related to ideas which he developed in the sixties, though I shall approach them from a rather different point of view. Early in life most of us fix on a number of lamp-posts under which ever after we look for things; for me these lamp-posts are algebraic topology and the theory of loop groups. My aim in this talk is very modest: I shall try to explain how the study of loop groups can shed some light on the possible properties of space.
Amalgamated Codazzi-Raychaudhuri Identity for Foliation
Authors: Carter Brandon 
Published: November 2023

Abstract
I wish to thank the editors of this volume for the opportunity of again expressing appreciation for the beautifully geometric way of perceiving the physical world that Roger Penrose communicated to so many students of my generation. In particular it was Roger’s emphasis (Penrose 1964) on the importance of features that are conformally invariant that led me, with his help, to develop the systematic use (Carter 1966) of 2-dimensional conformal projections (the Lorentz signature analogue of Mercator type projections in ordinary terrestrial mapping) of the kind that have since become widely and appropriately known as “Penrose diagrams”. An outstanding example of the kind of conformally invariant structure whose analysis was specially developed and applied under Roger’s leadership is that of null-geodesic foliations: in particular, it was his derivation, with Ted Newman (Newman and Penrose 1962) of the null limit of the famous divergence identity obtained originally for a time like flow by Raychaudhuri (1957), that provided the essential tool for deriving the singularity theorems that were subsequently developed, first by Roger himself (Penrose 1965), and later on by Stephen Hawking and others (Hawking and Penrose 1970; Hawking and Ellis 1973).
Twistor Solution of the Holonomy Problem
Authors: Merkulov S A , Schwachhofer L J 
Published: November 2023

Abstract
The holonomy group is one of the most informative characteristics of an affine connection. The problem of classifying all possible holonomy groups has a long history, beginning in the 1920s with the works of Cartan (1926a, b) who used this notion to classify locally symmetric Riemannian manifolds. Berger (1955) showed that the list of irreducibly acting matrix Lie groups which can, in principle, occur as the holonomy of a torsion-free affine connection must be very restrictive. This sharply contrasts a result of Hano and Ozeki (1956) which says that there is no interesting holonomy classification in the class of arbitrary affine connections—any closed subgroup of GL(n, ℝ) can be realized as the holonomy of an affine connection (with torsion, in general).
Afterword
Authors: Penrose Roger 
Published: November 2023

Abstract
Geometry, in its various forms, has always been one of my greatest delights—and even obsessions. In addition to the intrinsic beauty of the subject, there is the fact that geometry can also shed profound light on the deepest issues of science and philosophy—a wondrous fact that is indeed one of Nature’s miracles. One such a miracle was Einstein’s general relativity. But quantum theory, also, can in many respects be vastly illuminated by the geometrical perspective.
Geometry—formalisms and intuitions
Authors: Gray Jeremy 
Published: November 2023

Abstract
The change in our understanding of geometry in the nineteenth century, and especially around the end of that century, is astonishing. From being a core subject of elementary instruction, little changed from Euclid ‘s day, around which stood a modest number of more advanced ideas (algebraic curves, and the differential geometry of curves and surfaces) it embraced non-Euclidean geometry, new foundations in projective geometry, complex spaces, axiomatization, a transition from space to space-time, and numerous further alterations. Not least of these was a widening gap between the study of geometry and ideas about physical space. Its philosophical position was buffeted by these gales, its role as a supplier of intellectual certainty was severely questioned and some would say that in philosophical and psychological terms its former role has been severely eroded. All of this could have been regarded as highly technical and esoteric, of no practical relevance whatever, but it became one of the most notorious, well publicized changes in the whole of mathematics. It is worth picking through why this is. Some of the changes naturally interested philosophers. Some reasonably caught the attention of physicists, although quantum mechanics proved to be their consuming passion. But other such changes in mathematics and science have occurred without much public notice. It was not so with Poincare ‘s work, nor with Einstein ‘s. The extensive list of factors that promoted special and general relativity to center stage and made such an idol out of Einstein has been profitably debated at length. It includes many social aspects, such as the symbolic status of Eddington ‘s observations so soon after the First World War, and Einstein ‘s own personality.
Hilbert and physics (1900-1915)
Authors: Corry1 Leo 
Published: November 2023

Abstract
The name of David Hilbert (1862-1943) usually arises in connection with the history of physics in three different and rather circumscribed contexts. The first of these is the famous list of twenty three problems that Hilbert presented in 1900 in Paris, on the occasion of the Second International Congress of Mathematicians. The sixth problem of this list deals specifically with physics. Only one year before the Paris Congress Hilbert had published his seminal study on the foundations of geometry, Die Grundlagen der Geometrie. The axiomatic approach adopted by Hilbert in this book was to have an enormous influence on the development of twentieth century mathematics and on the way mathematicians looked at their science. Hilbert ‘s sixth problem was the suggestion that an analysis similar to that performed for the case of geometry in the Grundlagen should also be applied to individual physical disciplines.
The Göttingen response to general relativity and Emmy Noether ‘s theorems
Authors: Rowe David 
Published: November 2023

Abstract
Emmy Noether ‘s name is usually connected with the emergence of modern algebra at Gottingen during the 1920s. Although widely regarded by con temporary algebraists as the leading figure in the field, she was also known to both mathematicians and physicists-including Klein, Hilbert, Weyl, and Einstein-for her work on differential invariants and the connections between variational principles and conservation laws in physics. During the war years in Gottingen, Noether served as an assistant to Felix Klein and David Hilbert when both were immersed in work on general relativity theory. In this paper, I will not enter deeply into Naether ‘s published work nor will I discuss its impact on subsequent research. My purpose instead is to show the central part she played in the context of the overall response to general relativity by Gottingen mathematicians beginning with the ‘codiscovery ‘ of the gravitational field equations by Einstein and Hilbert in November 1915.
Characters
Authors: Freer Stephen 
Published: November 2023

Abstract
The FOUNDATION of botany (4) is two-fold, arrangement and nomenclature. [My] Systema naturae, veget. 2. ‘The foundation of botany consists in the systematic classification and nomenclature of plants: generic and specific.’ [My] Classes plantarum 4. ‘The names of plants ought to be definite, and accordingly placed in definite genera.’ Arrangement is the foundation of nomenclature.
Uniform convergence and power series
Authors: Priestley H A 
Published: November 2023

Abstract
As far as the development of integration theory is concerned much of this chapter is a side-track. It rounds off the study of continuous functions on compact intervals, investigating limits and infinite sums of such functions, and in particular power series. The arguments are quite elementary, but firmly rooted in the ε-δtradition. Our main technique is that of uniform convergence. We stress that uniform convergence rarely occurs (except locally) for sequences of functions on unbounded intervals. This makes it of limited value in our general theory. The powerful and widely applicable convergence theorems proved in Chapter 14 subsume the elementary results on limits of integrals we derive in this chapter.
Sums and integrals
Authors: Priestley H A 
Published: November 2023

Abstract
In Chapter 8 we considered term-by-term integration of series in the context of continuous functions on compact intervals. It is important to realize that the elementary arguments applicable there do not extend to functions on unbounded sets. In the general setting the convergence theorems can be used instead. The examples and exercises in this chapter make use of well-known series expansions; most of these are recalled in Appendix IL.
Three sequential algorithms
Authors: Karpinski Marek , Rytter Wojciech 
Published: November 2023

Abstract
In this chapter we present basic, sequential, polynomial time algorithms for matchings. The existence of any polynomial time algorithm for matchings in general graphs is a nontrivial fact. We discuss why these algorithms are hard to parallelize (in the sense of NC implementations). The first algorithm (of Hopcroft and Karp, see [HK73]) works efficiently for bipartite graphs and the two others work for general graphs. All of them have many variations which are quite interesting from the point of view of sequential computations. However, these variations would deserve a separate monograph and, as our main concern is parallel complexity, we concentrate only on basic sequential algorithms. They use augmenting paths as a main tool.
Special summability methods
Authors: Boos Johann , Cass Peter 
Published: November 2023

Abstract
After having become acquainted in Chapter 2 with several inclusion, comparison and consistency results it is time to put some life into the theory by considering (classes of) examples of summability methods. In this way we shall have the opportunity to apply theorems, proved in Chapter 2, to special matrix methods. In particular, we investigate the members of the classes concerning the properties defined in Chapter 2 like conservative (for null sequences), regular (for null sequences), coercive, type M, mean value property, potent, and so on.
A Few More Questions
Authors: David Guy , Semmes Stephen 
Published: November 2023

Abstract
We have already mentioned a lot of questions about the looking-down relation between BPI sets, but here is another one.
Problem 20.1 Suppose that M and N are BPI spaces of equal dimension which are not BPI equivalent (or even look-down equivalent) and that M looks down on N. Can we find a third BPI space T of the same dimension such that M looks down on T, T looks down on N, and T is not look-down equivalent to either M or N ?
Discretised Equations and Domain Decomposition Methods
Authors: Quarteroni Alfio , Valli Alberto 
Published: November 2023

Abstract
In this chapter the general principles previously introduced will be accommodated to treat the finite dimensional approximation of differential problems. We confine our analysis to the Poisson problem. However, its extension to the case of the more general symmetric elliptic boundary value problem (1.4.1) is straightforward and will be left to the interested reader. On the other hand, other kind of equations, either stationary or time-dependent, will be addressed from Chapter 5 onwards.
Longitudinal Vortices in Wavy Boundary Layers
Authors: Phillips W R C , Wu Z , Jahnke C C 
Published: November 2023

Abstract
Wind driven water waves are thought to arise owing to an instability in the atmospheric boundary layer above (2] and (3] or in the oceanic boundary layer beneath (4] the water surface. Both mean velocity profiles can be inflectional (5] although to date only non-inflectional profiles have been studied (6) and (7). Coupled with this instability is a further instability between the growing (or grown) waves and the boundary layer(s), giving rise to vortices more or less aligned with the wind. These vortices are essentially spanwise periodic with wavelengths as large as one kilometer in the ocean and three kilometers in the atmosphere. The former are known (after their discoverer) as Langmuir circulations (LC’s) and for clarity we shall refer to the latter as atmospheric Langmuir circulations (ALC’s).
Some Aspects of Wind-Wave Coupling at High Winds: an Experimental Study
Authors: Giovanangeli J P , Reul N , Garat M H , Branger H 
Published: November 2023

Abstract
Experiments were conducted in the IRPHE wind-wave facility in order to study the evidence and occurrence of air-flow separation above short wind waves. An original air-flow separation probe was designed and a Particle Image Velocimetry (PIV) technique in the air close to the surface was carried on. Measurements above steep waves clearly show air-flow separation at the crest, organised vortex motions with reverse flow above the leeward face and reattachment on the windward face of the downstream wave. Occurrence of air-flow separation grows linearly with wave steepness and decreases with wave age. The associated effects on wind-wave coupling are investigated.
Does the Wind Stress Depend on the Sea State?
Authors: Yelland Margaret J , Taylor Peter K 
Published: November 2023

Abstract
This paper discusses the effect of sea state on the drag coefficient (C D10N) to 10 m neutral wind speed (U10N) relationship, with particular emphasis on open ocean conditions. A large set of open ocean wind stress measurements were made using the inertial dissipation method during three cruises of the RRS Discovery in the Southern Ocean (Yelland and Taylor, 1996; Yelland et al., 1998; Yelland, 1997). These data were used to determine the mean CmoN to U10N relationship for open ocean conditions, and the extent of the influence of the sea state on this relationship is investigated (Section 2). Possible causes of the observed deviations of the drag coefficient from the mean relationship are discussed in Section 3. Section 4 contains a brief discussion on the disparity between results from open-ocean studies and those obtained by previous authors in coastal or other shallow water sites.
Observational Studies of the Surface Velocity Phase Structure of Microscale Breaking Wind Waves
Authors: Peirson W L 
Published: November 2023

Abstract
The phase structure of the surface velocity associated with wind-driven microscale breaking waves has been measured in a laboratory wind-wave flume using Particle Image Velocimetry (PIV) techniques. Contrary to previous studies, it is found that, on average, the surface flow at the crest does not contribute directly to the spilling regions of these small waves. In general, the net surface transport relative to the wave form is rear ward along the entire wave surface except in the immediate vicinity of the spilling region itself. Such findings have important implications in the de termination of appropriate surface boundary conditions for models of air flow over waves and theoretical and physical investigations of air-sea mass transfer.
Helix-Loop-Helix Transcription Factors
Authors: Littlewood Trevor D , Evan Gerard I 
Published: November 2023

Abstract
Helix-Loop-Helix (HLH) proteins are involved in transcriptional regulation of gene expression. The HLH domain is a DNA-binding dimerization domain which mediates homodimerization and heterodimerization with other HLH proteins. This new volume in the Protein Profile series explores the sequence specificity of DNA binding, the nature of dimerization partners, the regulation of target genes by HLH proteins, and the negative regulation of some bHLH proteins by HLH proteins which lack a functional DNA-binding domain. Topics include the role of HLH proteins in such diverse areas as myogenesis, neurogenesis, haematopoeisis, and sex determination; tissue specific HLH proteins; the role of HLH proteins in yeast and plants; nuclear localization of HLH proteins, transactivation domains and post-translational modification.
Introduction
Authors: Littlewood Trevor D , Evan Gerard I 
Published: November 2023

Abstract
The transcription of genes within eukaryotic cells is controlled by complex interactions between transcription factors and specific DNA recognition sequences in target genes. These DNA-binding transcription factors fall into a number of groups, each defined by shared sequence and, presumably structural, motifs. One such motif is the helix-loop-helix (HLH), first identified in an immunoglobulin enhancer-binding polypeptide as well as several other proteins known, or suspected, to be transcription factors [741]. The HLH region has also sometimes been referred to as the ‘Myc homology domain’, doubtless in deference to the notoriety and perceived importance of Myc proteins in carcinogenesis. However, the HLH motif is present in many proteins of diverse biological function and unified only by their common involvement in transcriptional regulation (reviewed in [3, 4, 32, 34, 43, 51, 62, 64, 69, 1312]). The HLH domain is a dimerization domain that mediates homo- and/or hetero-dimerization with other HLH proteins. The HLH domain is usually adjacent to a short region of basic residues that constitutes the sequence-specific DNA interaction interface; hence such proteins are often referred to as bHLH proteins. A second group of bHLH proteins contains an additional dimerization domain, the leucine zipper [1148], immediately C-terminal to the HLH. These proteins are commonly referred to as bHLHZ proteins. Members of a third group of HLH proteins lack a functional DNA-binding domain and act as negative regulators of bHLH proteins.
Structure/function relationships of HLH proteins
Authors: Littlewood Trevor D , Evan Gerard I 
Published: November 2023

Abstract
The bHLH proteins bind DNA as dimers and usually recognize short palindromic sequences (CANNTG) such that each protein monomer binds one haif-site. Immediately N-terminal to the HLH or HLHZ dimerization domain is a region of basic amino acids (b) presumed to mediate DNA binding. Sequence specificity is assumed to reside in the combination of the two basic domains in the dimer. Exceptions to this linear arrangement of basic domain and dimerization domain are a number of proteins with no recognizable basic domain such as Extramacrochaetae and Id (Fig. 2). These proteins, which are unable to bind DNA, inhibit the activity of bHLH proteins fry dimerizing with them to form inactive, non-DNA-binding, heterodimers. In structure, the bHLH domain comprises a short stretch of hydrophilic (often basic) residues (b) followed by a set of mainly hydrophobic residues located in two short segments (helix 1 and helix 2) and separated by a non-conserved sequence of variable length (the loop). The distribution of conserved residues within the HLH is consistent with the formation of two helices separated by a stretch of amino acids unfavourable for helix formation. Several groups have investigated the identities of amino acids at the beginning and end of such helices [1134, 1138, 1153, 1155] (reviewed in [1154]). These studies indicate that, apart from proline and glycine, there are certain amino acids that are more likely to be found at the boundaries of helices (referred to as the N cap and C cap residues). The N cap preferences, asparagine, serine and threonine, are often conserved at the beginning of the helices of HLH proteins. Recently the co-crystal structures of isolated homodimers of the E47, MyoD and USF bHLH and the Max bHLHZ each complexed with its specific recognition site have been reported [1142, 1143, 1144, 1149] (reviewed in [1137, 1141, 1152, 2049]) (Fig. 3).
Sequence-specific DNA binding by HLH proteins
Authors: Littlewood Trevor D , Evan Gerard I 
Published: November 2023

Abstract
Virtually all bHLH and bHLHZ proteins bind specifically to a consensus hexameric DNA sequence (CANNTG) known as the E box. E box sequences are often palindromic and contain identical half-sites, each of which may be bound by one component of the dimer. Although the central dinucleotides of the E box are usually GC or CG, exceptions have been noted. The preferred E box sequences bound by known HLH proteins are summarized in Table 3. It is of note that several independent HLH factors within one species often bind the same sequence, implying the existence of mechanisms for regulating precisely which HLH protein is bound to the E box in the control region of a given gene at any one time. Sometimes, this involves differential expression of iso-specific factors within specific cell lineages. Often, however, several bHLH/bHLHZ factors coexist within a cell. One possible mechanism dictating specificity of binding may reside in additional sequence specificities flanking the consensus E box element.