bluuebunny/crossref_metadata_2025_split huggingface dataset:
GPCR superfamily and its structural characterization
Authors: Schöneberg Torsten 
Published: November 2023

Abstract
The diversity of receptor groups within the GPCR superfamily is the result of a long evolutionary process. It has been suggested that serotonin (5-HT) receptors have existed for more than 750 million years (Peroutka and Howell 1994). The tendency towards protein diversification depends upon gene duplications and the continuous accumulation of mutations. The maintenance of vital functions in organisms, however, strictly requires enough structural conservation to ensure the functionality of the corresponding proteins. Despite the remarkable structural variety of natural GPCR agonists, hydropathy analysis, biochemical, and immunological data suggest that all GPCRs share a common molecular architecture consisting of seven transmembrane domains (TMDs) connected by three extraand three intracellular loops. Interestingly, this global architecture is maintained in all GPCRs discovered so far, despite a rather low amino acid sequence homology.
Transcriptional regulation of GPCR expression
Authors: Buckley Noel J , Garriga-Canut Mireia 
Published: November 2023

Abstract
G protein coupled receptors (GPCRs) represent the largest family of signalling molecules present in the organism and are found in all phyla from viruses through yeast to mammals. This sequence diversity is reflected in their expression patterns which invariably show that each transcript has a unique distribution. As anticipated, this diversity of gene type and distribution is most manifest in the CNS. This poses both problems and opportunities. On the one hand, such unique distributions offer potential for highly specific therapeutic targets. On the other hand, they present a problem of phenotypic regulation: How are these expression patterns established and maintained? It is this latter aspect that is the focus of this review.
Structural mechanics of GPCR activation
Authors: Rasmussen Søren G F , Gether Ulrik 
Published: November 2023

Abstract
The majority of hormones, neurotransmitters, and other chemical signalling molecules in the human body exert their effects via G protein coupled receptors (GPCRs) (Strader et al. 1994; Ji et al. 1998; Gether 2000). Evidently, this extreme functional diversity raises some fundamental questions in relation to the function of GPCR at the molecular and cellular level. What are, for example, the molecular mechanisms underlying the ability of this broad variety of molecules to bind and activate receptors that presumably share a preserved overall tertiary structure? Or more specifically, what are the physical changes linking binding of an agonist to activation of intracellular signalling cascades? During the last few years our insight into these fundamental mechanisms have improved considerably. An important breakthrough has been the application of biophysical approaches that has allowed direct insight into the conformational changes that accompany activation of a GPCR (see Gether 2000; Hubbell et al. 2000).
Characterization of orphan GPCRs
Authors: Fidock Mark 
Published: November 2023

Abstract
Bioinformatic analysis of sequence databases to identify new GPCR family members based on homology and conserved ‘motifs’ to known GPCRs suggests that the total number of GPCRs is likely to be around 350 (this does not include olfactory, taste or opsin receptors, see chapter 1). Of these 350, the number which are currently classified as ‘orphans’ (that is receptors without a defined physiologically relevant ligand) is in the region of 175. These ‘orphans’ typically show low sequence identity (&lt; 40%) to known receptors and are distributed throughout the entire GPCR phylogenetic tree. A large number show greater sequence identity to each other than to any known GPCR suggesting they are new subfamilies with distinct, possibly novel ligands.
Introduction And Overview
Authors: Iwaniec Tadeusz , Martin Gaven 
Published: November 2023

Abstract
The interplay between partial differential equations (PDEs) and the theory of mappings has a long and distinguished history, and that connection underpins this book. Gauss’s practical geodesic survey work stimulated him to develop the theory of conformal transformations, for mapping figures from one surface to another. For conformal transformation from plane to plane he used a pair of equations apparently derived by d’ Alembert, who first related the derivatives of the real and imaginary part of a complex function in 1746 in his work on hydrodynamics (31], p. 497. These equations have become known as the Cauchy–Riemann equations. Gauss developed the differential geometry of surfaces around 1827, emphasizing the intrinsic geometry, with Gaussian curvature defined by measurements within the surface. If a surface is deformed conformally (preserving angles), then the Gaussian curvature is unchanged, and hence the intrinsic geometry of the surface is unaffected by such deformations. Gauss also considered geodesic curves within surfaces. In 1829 Lobachevsky constructed a surface (the horosphere) within his non-Euclidean space, such that the intrinsic geometry within that surface is Euclidean, with geodesic curves being called Euclidean lines. For the converse process, he could only suggest tentatively that, within Euclidean space, the intrinsic geometry of a sphere of imaginary radius was Lobachevskian. But imaginary numbers were then regarded with justifiable suspicion, and he did not propose that as an acceptable model of his geometry within Euclidean space. In his most famous work, Beltrami [32] showed that Lobachevsky’s geometry is the intrinsic geometry of a surface of constant negative curvature, with geodesic curves being called lines in Lobachevsky’s geometry. Beltrami illustrated various surfaces with constant negative curvature, the simplest of which is the pseudosphere generated by revolving a tractrix around its axis. Beltrami’s paper convinced most mathematicians that the geometries of Euclid and of Lobachevsky are logically equivalent. In that work Beltrami used a differential equation corresponding to Gauss’s equation. This has come to be known as Beltrami’s equation, and later in this book we shall present the most recent developments in this area, solving Beltrami’s equation at the critical point. where uniform ellipticity bounds are lost. This will necessitate the development of some considerable technical machinery to enable us to move away from the classical setting of uniformly elliptic PDEs to the case of degenerate elliptic equations. Beltrami’s equation and its solutions, the quasiconformal mappings, have found a home in virtually all aspects of modern complex analysis, from the theory of Riemann surfaces and Teichmüller and Moduli spaces to more recent developments such as holomorphic dynamics and three-dimensional hyperbolic geometry. We hope the developments presented in this book encourage new applications of quasiconformal mappings in these areas.
Conformal Mappings
Authors: Iwaniec Tadeusz , Martin Gaven 
Published: November 2023

Abstract
This chapter is intended as a gentle introduction to the basic notions of conformal geometry. In this way we are able to introduce and discuss some concepts from differential geometry which we will need later. We meet Möbius transformations and then prove Liouville’s celebrated rigidity theorem of 1850, that conformal diffeomorphisms of ℝ,. n2: 3, are Möbius transformations. This proof serves as a model for our subsequent proof of this theorem in much greater generality.
Stability Of The Mobius Group
Authors: Iwaniec Tadeusz , Martin Gaven 
Published: November 2023

Abstract
Liouville’s theorem demonstrates the strong rigidity of conformal mappings in dimensions n≥ 3. An important point to note from the previous chapter is the global injectivity of nonconstant solutions to the Cauchy–Riemann system. It is natural to ask if this property is still true for “nearly” conformal mappings. In order to answer this question we shall need to examine fairly general classes of mappings defined on subdomains of ℝn. Naturally the classes of mappings in question should remain invariant under elementary changes of variables, such as scaling and translation, since the Möbius group is. We shall show that if these classes are close to the Mobius class in a well-defined sense, then they inherit some of the rigidity properties, in particular local injectivity. (Indeed, they will be shown to consist of locally quasiconformal mappings).
Differential Forms
Authors: Iwaniec Tadeusz , Martin Gaven 
Published: November 2023

Abstract
There are important applications of the L-theory of differential forms in nonlinear analysis. In particular, many recent developments in the areas of quasiconformal mappings and non-linear elasticity are founded on the framework provided by non-linear Hodge theory. When p= 2, the theory is fairly well understood and presented in many textbooks. However for p≠ 2, the LP-theory of differential forms has yet to be fully developed. In this chapter we expose many of the standard techniques used when p= 2 and add critical new techniques for p≠ 2.
Riesz Transforms
Authors: Iwaniec Tadeusz , Martin Gaven 
Published: November 2023

Abstract
Singular integrals have played an important role in the theory of partial differential equations from the very beginning, largely pertaining to the higher integrability theory of the gradient of weak solutions. It is only recently that we have become fully aware of the importance of computing, or at least obtaining good estimates for the p-norms of such operators – for example, in determining the exact degrees of improved regularity and other geometric properties of solutions for both linear and non-linear PDEs in higher dimensions.
Conformal Structures
Authors: Iwaniec Tadeusz , Martin Gaven 
Published: November 2023

Abstract
In the next few chapten; we are going to need to have at hand some facts concerning conformal structures on domains in ℝn and the mappings between them. The aim in this brief chapter is to present this material. It is in this differential-geometric setting that many ideas crystallize, and further generalizations become apparent.
Advances in Bayesian image analysis
Authors: Hurn Merrilee , Husby Oddvar , Rue Havard 
Published: November 2023

Abstract
Statistical interest in data in the form of images really took off in the 1980s following the papers by Geman and Geman (1984) and Besag (1986), although in fact Grenander had been working in the area of pattern recognition for some considerable time by then (Grenander 1976, 1978, 1981).
Perspectives on the timing of events and actions Introduction to Section II
Authors: Summers Jeff 
Published: November 2023

Abstract
Time perception in terms of the temporal properties of environmental events and time production in terms of the execution of self-generated sequences of precisely timed movements are abilities that are essential for successful interactions with the world around us. Furthermore, coordinating our actions in time to coincide with an external event, that is, perception–action coupling, is a feature of many everyday activities, from pressing a key on a piano, to shaking someone’s hand or hitting a squash ball. Unfortunately the study of the perception of event structure (i.e. the motional and rhythmic properties of events) and the study of movement timing have progressed somewhat independently, leaving the crucial question of how perceptual variables map onto motor variables largely neglected. In this section four papers are presented dealing with different aspects of timing.
Action representation and the inferior parietal lobule
Authors: Gallese Vittorio , Fadiga Luciano , Fogassi Leonardo , Rizzolatti Giacomo 
Published: November 2023

Abstract
Abstract. From birth onwards, primates’ cognitive development depends heavily on being able to observe and interact with other individuals. How can individuals assign a meaning to the actions performed by other conspeci1cs? A possible neural correlate of the mechanism allowing action understanding could be represented by a class of neurons (mirror neurons) that we have discovered in area F5 of the ventral premotor cortex of the macaque monkey. We proposed that mirror neurons could be part of a cortical system that, by matching action observation with action execution, enables individuals to ‘understand’ the behavior of others. The present study is aimed at better clarification of the nature and the properties of such a cortical matching system. Neurons responding to the observation of complex actions have been described by Perrett and co-workers in the cortex buried within the superior temporal sulcus (STS). These neurons could be a particularly well-suited source of visual input for F5 mirror neurons. However, area F5 does not receive direct projections from the STS region. One of its major inputs comes from the inferior parietal lobule and in particular from area PF (7b).
Coordination and integration in perception and action Introduction to Section V
Authors: Ward Robert 
Published: November 2023

Abstract
Integration of perception and action systems is necessary for survival. A perceptual system which can’t guide action is literally useless, and an action system which isn’t guided by perception is probably dangerous. So how are perception and action systems linked to allow effective behaviour? The chapters in this section address many aspects of this question, but at least two important themes emerge. One is the increasing variety of approaches that develop and even replace traditional notions about the way perceptual analyses are dynamically linked to responses. A second crucial issue is the way that associations between stimuli and response are structured by experience and by task demands.
Green’s equivalences; regular semigroups
Authors: Howie John M 
Published: November 2023

Abstract
The notion of ideal mentioned in the last chapter leads naturally to the consideration of certain equivalence relations on a semigroup. These equivalences, first studied by J. A. Green (1951), have played a fundamental role in the development of semigroup theory. They are concerned with mutual divisibility of various kinds, and all of them reduce to the universal equivalence in a group.
Inverse semigroups
Authors: Howie John M 
Published: November 2023

Abstract
In planning the chapter on inverse semigroups the main problem has been one of selection. As long ago as 1961, Clifford and Preston offered the opinion that inverse semigroups were the most promising class of semigroups for future study, and the intervening years have amply justified their forecast. It is inappropriate in a general introductory book to attempt a comprehensive updating of Petrich’s (1984) very complete account. Rather I shall cover the basic ideas and attempt to explore one or two avenues in more detail.
Computer-based Radiological Training and Education
Authors: Jeffery* N P , Teather* D A , Teather* D , Sharples** M , Boulay** D Du , Boulay† G H Du 
Published: November 2023

Abstract
In teaching radiology residents and medical students, there is now the problem of transmitting a larger amount of material in what appears to be an increasingly inadequate time span. Despite the fact that the length of radiology training has heen extended, it is no longer possible for finishing residents and fellows to know all that they need to know if they are going to enter the practice of radiology. There is therefore a need for professional updating and supplementary teaching. Training and education in radiology depend to a large extent on visual pre sentation [l]. The transfer of information in radiology, as in all of medicine, has traditionally been in standard teaching formats such as an instructor lecturing to a group of students, one-to-one discussions, and direct hands on experience.
Constructive truth in practice
Authors: Bridges Douglas S 
Published: November 2023

Abstract
In this chapter, which has evolved over the last ten years to what I hope will be its perfect Platonic form, I shall first discuss those features of constructive mathematics that distinguish it from its traditional, or classical, counterpart, and then illustrate the practice of that distinction in aspects of complex analysis whose classical treatment ought to be familiar to a beginning graduate student of pure mathematics.
My experience shows that a typical mathematician believes that constructive mathematics is characterized by either a rejection of the law of excluded middle from logic or else a rejection of the full axiom of choice from set theory. In fact, although some authors (notably Richman (1996)) seem to endorse the former characterization, the pioneers of constructivism—Brouwer, Markov, Bishop-all arrived at their rejection of the law of excluded middle (and hence, implicitly, at a rejection of the axiom of choice—see later in this chapter) as a consequence of their insistence that the phrase there exists be interpreted strictly as we can construct.
The mathematician as a formalist
Authors: Dales H G 
Published: November 2023

Abstract
The existence of this meeting bears testimony to the anodyne remark that there is a continuing debate about what it means to say of a statement in mathematics that it is ‘true’. This debate began at least 2500 years ago, and will presumably continue at least well into the next millennium; it would be implausible and perhaps presumptuous to suppose that even the union of the talented and distinguished speakers that have been assembled here in Mussomeli will approach any solution to the problem, or even arrive at a consensus of what a solution would amount to.
True to the pattern
Authors: Oliveri Gianluigi 
Published: November 2023

Abstract
The aim of this chapter is to sharpen and defend the view advocated by Wittgenstein in Philosophical Investigations that an aspect is not ‘[…] a property of the object, but an internal relation between it and other objects’.
This conception of aspects is philosophically very important for the following reasons.
First, it provides a view of experience which differs from that inherited by a large part of the post-Kantian tradition.
Black Holes Gravitational Interactions
Authors: D'eath P D 
Published: November 2023

Abstract
Black Holes are regions of space-time where the gravitational field is so strong that not even light can escape. There has been much written on black holes, however in most cases they are treated as isolated objects. In this important new book, the author has found a number of cases in which the interaction of a black hole with another strong-field system (such as the background universe or another black hole) could be treated analytically. This includes using the powerful method of matched asymptotic expansions, and these wider ranging problems and examples are considered here for the first time. In addition to a thorough treatment of the equations of motion for a pair of black holes, the book provides a useful treatment of the standard theory for these objects. It will be widely read by all those working in gravitation, along with post-graduate students in mathematical physics.
On the Homotopy Classification of (N − 1)-Connected (n + 3)-Dimensional Polyhedra, n≥4
Authors: Baues Hans-Joachim 
Published: November 2023

Abstract
J.H.C. Whitehead in 1948 classified (n −1)-connected (n + 2)-dimensional homotopy types. Since then it has been a challenging problem to consider the next step in the classification of (n − 1)-connected (n + 3)-dimensional homotopy types. Various authors have worked on this problem in the stable range n≥ 4, for example Shiraiwa [HT], Uehara [HT], Chang [PI], [HT], [AS], [NH], and Chow [HG]. They use a complicated method of primary and secondary cohomology operations; compare Section 8.5 below. We here apply the new method of boundary invariants which, via the classification theorem 3.4.4, yields fairly simple classifying data for (n − 1)-connected (n + 3)-dimensional homotopy types. In this chapter we deal only with the stable case n≥ 4. In Chapters 9 and 12 we describe the considerably more intricate unstable cases, n = 3 and n = 2.
Partial Orders
Authors: Brightwell Graham 
Published: November 2023

Abstract
We explore several connections between graphs and partially ordered sets. We define various graphs and digraphs associated with a partially ordered set, and explore how the properties of the partial order are reflected in these graphs. We consider the incidence order of a graph, and prove Schnyder’s Theorem, that a graph is planar if and only if its incidence order has dimension at most 3. It is possible, and only moderately perverse, to think of a graph as a special kind of partially ordered set. Then again, a partially ordered set can be regarded as nothing more than a special kind of directed graph. One should be wary of concluding that the concerns of one subject are similar to those of the other, or that results from one area are necessarily of use in the other, but it is not unreasonable to expect that there will be connections. This chapter is devoted to some of those links that have proved interesting.
Statistics
Authors: Wild Peter 
Published: November 2023

Abstract
In this chapter we give several examples of the close connection between statistical design and graph spectra. Focusing on block designs, we describe measures of efficiency of an experimental design in terms of certain functions of eigenvalues of the Fisher information matrix. The most efficient designs correspond to graphs with some extreme spectral behaviour. One of the main aims of mathematics is to model problems that arise in the real world–that is, to represent a real-life situation as a mathematical system. By this means, many different instances of the same problem can be tackled using a single theory. This theory may be descriptive, providing a clearer understanding of the problem. It may also be a tool that can be used to prove previously unsuspected results that may be applied to the real-life situation to make predictions about its behaviour.
Local Compactness And Exponentiability
Authors: Johnstone Peter T 
Published: November 2023

Abstract
Our principal goal in this chapter is to establish the characterization of exponentiable objects in the 2-category ℬℐℴ𝓅/𝒮, for a general base topos 𝒮, as those which are ‘locally compact’ in an appropriate sense. We have already made some observations about exponentiability in ℬℐℴ𝓅/𝒮 in Section B4.3; and we shall assume that the reader of this chapter is familiar with them. In this and the next section we shall take our base topos to be Set, in order to simplify the notation; but virtually all that we do can be extended to a general base topos S with a natural number object, using an appropriate internal finiteness notion in S to interpret the finiteness conditions which appear below.
Cognitive–Behavioral Group Interventions
Authors: Coon David W , Shurgot Gia Robinson , Gillispie Zoë , Cardenas Veronica , Gallagher–Thompson Dolores 
Published: November 2023

Abstract
This research was supported through the Resources for Enhancing Alzheimer’s Caregiver Health (REACH) project, which is funded by the National Institute on Aging (grant no. AG 13289) to DGT, Principal Investigator at this site.