bluuebunny/crossref_metadata_2025 huggingface dataset:
Lattice Gas Cellular Automata
Authors: Succi Sauro
Published: November 2023

Digital arithmetic is to scientific computing as collisions of molecules are to fluid mechanics: crucial to the implementation, but irrelevant to most scientific questions . L. N. Trefehen, ‘Maxims about numerical mathematics, computer science and life’, SIAM News , Jan/Feb, 1998. In 1986, Uriel Frisch, Brosl Hasslacher and Yves Pomeau produced their wonderful bombshell: a simple cellular automaton obeying nothing but conservation laws at a microscopic level was able to reproduce the complexity of real fluid flows [18]. This discovery caused great excitement in the fluid dynamics community. The prospects were promising: a round-off free, intrinsically parallel computational paradigm for fluid flows, perhaps, even more, the analogue of the Ising model for turbulence! However, a few serious problems were quickly recognized and addressed with great intensity in the following years.
Lbe Flows In Disordered Media
Authors: Succi Sauro
Published: November 2023

The study of transport phenomena in disordered media is a subject of wide interdisciplinary concern, with many applications in fluid mechanics, condensed matter, and life and environmental sciences as well. Flows through grossly irregular (porous) media is a specific fluid mechanical application of great practical value in applied science and engineering. It is arguably also one of the applications of choice of the LBE (and LGCA) methods. The dual field–particle character of LBE shines brightly here: the particle-like nature of LBE (populations move along specific particle trajectories) permits a transparent treatment of grossly irregular geometries in terms of elementary mechanical events, such as mirror and bounce-back reflections. On the other hand, the field-like nature of LBE (populations carry smooth, hydrodynamic information) permits achievement of fluid dynamic behavior also in tiny interstitial regions of the flow which are hardly accessible to the macroscopic approach. These assets were quickly recognized by researchers in the field, and still make of LBE (and LGCA) an excellent numerical tool for microhydrodynamic flows in porous media.
Functional roles of microsatellites and minisatellites
Authors: Kashi Yechezkel , Soller Morris
Published: November 2023

A number of lines of evidence are reviewed showing that microsatellite and minisatellite sequences serve as functional coding and regulatory elements in the eukaryote genome. These include the presence of homopolymeric amino acid tracts in numerous proteins, conservation of microsatellites in relation to coding sequences, and ability of microsatellites to bind proteins and to serve as enhancer elements in expression constructs. Variation in microsatellite repeat number is found to have pronounced effects on their regulatory and coding functions, and is associated with phenotypic variation at both the biochemical and organismic levels. The combination of high mutation rate and regulatory/coding function raises the possibility that microsatellites are a major source of eukaryotic genetic variation.
Minisatellites and mutation processes in tandemly repetitive DNA
Authors: Armour John A L , Alegre Santos Alonso , Miles Sue , Williams Louise J , Badge Richard M
Published: November 2023

Detailed analysis of mutational processes at some human minisatellite loci is possible because of the very high rates of germline mutation and the presence of internal structural variation. This variation in the distribution of variant repeat units can be used both to survey allelic variation across populations and to define the structural basis of length change mutations. More recently, the fidelity with which minisatellite alleles can be amplified by PCR (even from the single molecule level) has allowed direct assays of germ line mutation from sperm DNA samples. The unexpected features of minisatellite mutation include polarity, recombinational exchanges between alleles, and mutation rate variation between alleles. The implications of these studies for our view of microsatellite mutation and evolution will be discussed.
Statistics of microsatellite loci: estimation of mutation rate and pattern of population expansion
Authors: Chakraborty Ranajit , Kimmel Marek
Published: November 2023

Applications of microsatellite loci in evolutionary studies are based on examination of the expectations of summary statistics of genetic variation at these loci, under a model for mutation and genetic drift. Usually, the single-step stepwise mutation model with unrestricted allelic states is assumed, and the effect of genetic drift is studied by assuming that the population size is constant over time. In this chapter, we illustrate the effects of relaxing both of these assumptions. We show that an expansion or contraction of population size over time leaves a signature on the genetic variation that can be detected by estimating the composite parameter (the product of population size and the mutation rate) from heterozygosity and allele size variance. Allele size restrictions also produce an imbalance between heterozygosity and allele size variance. These two statistics are insensitive to directional (expansion/contraction) bias of mutations if allele-size constraints are absent. Further, the feature that microsatellite alleles can be ordered by their sizes allows estimation of relative mutation rates of loci grouped by their biological properties. Applications of these principles to microsatellite data from several human populations indicate that the mutation rates are inversely related to the motif size, and the African populations exhibit indications of the most ancient human bottleneck.
Integrable Systems and Twistors
Authors: Richard Ward , Martin Speigh
Published: November 2023

For the purpose of this chapter, integrable systems are special kinds of non-linear differential equations (although one should note that there are also integrable difference equations, and the study of these is increasingly prominent). For essentially any system of differential equations, one has local existence theorems, so existence of solutions is not the issue. The question, rather, is what the solutions are like. For a non-linear differential equation chosen at random, one has no hope of writing down explicit solutions in terms of known functions. The classification of a function as ‘known’ may seem artificial, having more to do with what we’ve bothered to learn than the function itself; but in fact there is more to it than that. The known functions (e.g. trigonometric functions or elliptic functions) are known because they have nice properties, and can be defined using only a finite amount of information. The functions involved in the solutions of a generic nonlinear differential equation are so awful as to be literally indescribable in any but a tautological way (that is, one can really only define them as solutions of the differential equation). An extreme example of this is chaotic systems.
Genetic Destinies
Authors: Little Peter
Published: November 2023

On the last day of August in the year 2020 two girls are born. Genetic science enables the long life of one of them to be happy and free of suffering; she finally dies in 2140. In stark contrast, genes fill the life of the other with discrimination and oppression, and after enduring much misery she dies young, in 2048. These 'future histories' of two individuals provide a striking opening to Genetic Destinies. In the chapters that follow, Peter Little discusses the reality of the power of gene science in clear, non-technical language wholly accessible to the general reader. After explaining what genes are, and what role they have in making us human, he explores an intriguing paradox of genes: not only do they make us look similar, they also contribute to the differences between us. He shows how the distant origins of human beings influence our present and, with a carefully dispassionate eye, examines the socially contentious issues of 'race' and gene differences. The intricate interplay of genes, gene differences, and lifestyle leads to the thought-provoking realization that not only do gene differences describe our past, they also contribute to our futures--shown by the role of genes in making us healthy or diseased, in forming the human brain and mind, and influencing our personalities and our intelligence. It is an interplay of great complexity. Based on this understanding Peter Little carefully leads the reader through the potential of using gene technology to remake human beings and shows why this is unlikely to become a practical reality. This knowledge takes the reader to the very cutting edge of current genetics. Genetic Destinies ends by returning to the lives of the two fictional women and uses their future histories to show that the fears we have of gene science are based on misplaced ideas of the power of genes. The reality is that we all have a personal destiny, but we have no way of predicting what it will be. Our genes, and the differences they contain, have moulded us from the moment of conception but, as our genes and our lives combine in an intricate dance of mutual influence, we face myriad genetic destinies. Our true genetic destiny is to live our lives as human beings--unique, unpredictable, and irreplaceable in all of history and all of future time: a wonderful prospect.
Genes, dreams, and nightmares
Authors: Little Peter
Published: November 2023

In the early hours of the morning of the last day of August in the year 2020 two girls were born; this is the story of their lives, told as their future history might be. The chapters that follow contain the science of why their lives might, or might not, unfold in these ways and they are concerned with genes and how they influence our existence. As we will see, our personal futures are in our own hands but they are also in the hands of our genes: these are our Genetic Destinies.
Where do all the differences come from?
Authors: Little Peter
Published: November 2023

Jean and Jeanne are genetically distinct and their histories make this obvious, but what is not so apparent is whether they are unusual in this respect. Are all people different or just those that have widely different origins—say Africans compared with Europeans or Chinese compared with Indians? The reality is that gene differences are actually very common so that we are all different, one from another. To understand why this is so, we have to go back a step in our thinking about differences in genes.
Differences, genes, and lives
Authors: Little Peter
Published: November 2023

The future lives of Jeanne Dream and Jean Battler were moulded by gene differences and environment. Perhaps it is worth trying to consider what Jean Battler’s life might have been like if she had the environment of Jeanne Dream: what would have been better, what would have been worse? We cannot know with certainty but we can guess it would have been a different and, perhaps, happier life. For all of us, gene differences are one of the determinants of the quality of our lives and this is true for every living species. More significantly gene differences are the route to death and survival in the face of a changing and often malign world: they are a key to individual and collective survival.
Intelligence and the four-way tangle
Authors: Little Peter
Published: November 2023

All of us believe we can recognize intelligence but I think it would take each one of us a good deal of time to write down exactly what it is that we feel is represented by intelligence and what it means to possess it; indeed, large numbers of books have been written on the topic and even greater numbers of articles in scientific journals. The difficulty in one way is not profound, for intelligence is not a simple ‘property’ like weight, length, or height that can be estimated on a scale or with a balance, and so it cannot have a simple and objective measure. Many features of human existence are similarly insubstantial—beauty, friendship, and happiness—whose existence we all recognize, even if we would argue over their definition.
Dreams and nightmares revisited
Authors: Little Peter
Published: November 2023

We can now revisit these tales with a much firmer grasp of their underlying scientific principles and look at the reality behind the stories. In doing this, we have three goals in mind: the first is simply to decide what is possible, what is impossible, and what lies in between these extremes. Our second goal is to draw lessons as to why the lives of Jeanne Dream and Jean Battler are so incomparably different. By the end of this chapter we will have met each of these goals and we will be ideally positioned to confront the fears that surround much genetics today. To understand the source and reality of our widespread distrust of this science will become our third goal.
Bayesian Methods in the Atmospheric Sciences
Authors: Berliner L Mark , Royle J Andrew , Wikle Christopher K , Milliff Ralph F
Published: November 2023

Current issues in the atmospheric and allied sciences are of fundamental interest to both the scientific community and the general population. We briefly review some of these issues and the basic methods by which they are typically analyzed. The goal of this review is to motivate numerous challenges to the Bayesian Statistics community. Two essential aspects amenable to Bayesian analyses are (1) the efficient combination of information (“science” and “data”), and (2) the quantification and management of uncertainty. In the face of the complexities arising from the presence of massive datasets as well as nonlinear physical models, we suggest Bayesian hierarchical modeling and analysis as a fundamental strategy for statistical approaches to problems of weather and climate science. We present a review of our work in an ongoing project employing physical principles and satellite (scatterometer) data providing information on sea-surface winds.
Exact Sampling for Bayesian Inference: Towards General Purpose Algorithms
Authors: Green Peterj. , Murdoch Duncan J
Published: November 2023

There are now methods for organising a Markov chain Monte Carlo simulation sb that it can be guaranteed that the state of the process at a given time is exactly drawn from the target distribution. The question of assessing convergence totally vanishes. Such methods are known as exact or perfect sampling. The approach that has received most attention uses the protocol of coupling from the past devised by Propp and Wilson (Random Structures and Algorithms, 1996), in which multiple dependent paths of the chain are run from different initial states at a sequence of initial times going backwards into the past, until they satisfy the condition of coalescence by time 0. When this is achieved the state at time 0 is distributed according to the required target. This process must be implemented very carefully to assure its validity (including appropriate re-use of random number streams), and also requires use of various tricks to enable us to follow infinitely many sample paths with a finite amount of work.
Bayesian and Frequentist Approaches to Parametric Predictive Inference
Authors: Smith Richard L
Published: November 2023

Suppose we want to estimate predictive probabilities for an unobserved random variable, whose distribution depends on an unknown finite-dimensional parameter which is estimated from past data. A crude “plug-in” approach is to substitute a point estimate of the unknown parameter into the predictive distribution. This may be criticized as failing to take into account the uncertainty of the unknown parameter, whereas a Bayesian approach incorporates such uncertainty in a natural way. Therefore, we might expect that a Bayesian procedure will be superior to a plug-in approach even when assessed in purely frequentist terms. The analysis given in this paper, however, shows that this is too simple a conclusion. For many models, when assessed from the point of view of mean squared error of predictive probabilities, the plugin approach is superior to the Bayesian approach in the extreme tail of the distribution. We may also consider alternative loss functions besides mean squared error, but in most cases a similar phenomenon occurs. However, one may also generalize the class of Bayesian procedures by considering alternatives to the posterior mean of the predictive distribution. With such generalizations, the comparison swings back in favor of Bayesian procedures. These results are initially developed for simple models, in particular the exponential distribution, but in later discussion they are used to study the properties of hierarchical modeling approaches to empirical Bayes problems. The mathematical development is only sketched in the present paper, but relies heavily on asymptotic expansions and second-order properties.
Robustifying Bayesian Procedures
Authors: Walker Stephen G , Gutierrez-Pena Eduardo
Published: November 2023

In this paper we discuss two approaches to robustifying standard Bayesian procedures. The first involves regarding common statistical problems as decision problems where the ‘relevant unknown’ is modelled nonparametrically. Problems considered include model selection, empirical Bayes inference and interval estimation. In particular we generalise a model selection criterion of San Martini and Spezzaferri (1984). The second approach is based on suitable generalisations of well-known densities. For example, we generalise the standard normal density to include both skewness and kurtosis.
The Nile Revisited: Changepoint Analysis with Autocorrelation
Authors: Garisch Isabelle , Groenewald Pieter C N
Published: November 2023

Bayesian changepoint analyses in the linear model is examined when the errors are correlated. Bayes factors and posterior probabilities are derived for the number of changepoints and positions of changepoints in a sequence of random variables. The principle of partial Bayes factors is applied through the fractional and intrinsic Bayes factors.The methods are applied to the well-known data of annual discharge of the Nile river at Aswan, as well as to an example of a multiphase bacterial growth model. It appears that, while the autocorrelation has little effect on the estimated positions of the changepoints, the presence of changepoints can have a substantial effect on the estimation of the correlation coefficient.
Non-Stationary Spatial Modeling
Authors: Higdon David , Swall Jenise , Kern John
Published: November 2023

Standard geostatistical models assume stationarity and rely on a variogram model to account for the spatial dependence in the observed data. In some instances, this assumption that the spatial dependence structure is constant throughout the sampling region is clearly violated. We present a spatial model which allows the spatial dependence structure to vary as a function of location. Unlike previous formulations which do not account for uncertainty in the specification of this non-stationarity (eg. Sampson and Guttorp (1992)), we develop a hierarchical model which can incorporate this uncertainty in the resulting inference. The non-stationary spatial dependence is explained through a constructive ‘‘process-convolution” approach, which ensures that the resulting covariance structure is valid. We apply this method to an example in toxic waste remediation.
The Origins of Life
Authors: Maynard Smith John , SzathmáRy EöRs
Published: November 2023

Living organisms are astonishingly complex. And the more we know about them - their biochemistry, their anatomy, their behaviour - the more astonishing are the detailed adaptations that we discover. How could this complexity have arisen? Most of us are familiar with Darwin's theory of evolution by natural selection. The idea behind it being that, in nature, those individuals best able to survive and reproduce will transmit the characteristics that enabled them to do so to their offspring, leading to the evolution of traits beneficial to the organism. Although Darwin's idea is simple - perhaps because it is so simple - it is hard to believe that it is able to explain the complexity of the living world. We can breed cows that produce more milk compared with earlier generations, say, but we cannot breed pigs that fly, or horses that can talk: there would be no promising variants that we could select and breed from. Where, then, does the variation come from that has made possible the evolution of ever-increasing complexity in the wonderfully adapted organisms we see around us? In answering this central question, John Maynard Smith and Eors Szathmary present for a general readership a novel picture of evolution. Their basic idea is that evolution depends on changes in the information that is passed between generations, and that there have been a number of 'major transitions' in the way that information is stored and transmitted. These transitions include the appearance of the first replicating molecules - the origin of life itself; the origin of cells; reproduction by sexual means; the appearance of multicellular plants and animals; the emergence of cooperation and of animal societies; and the unique language ability of humans. Here, then, is an accessible account of contemporary biology on the grandest scale, from the birth of life to the origin of language. Containing many original ideas, and covering many of the most fundamental ideas in biology, this important and deeply interesting book will appeal both to readers with little prior knowledge of science and to biologists themselves.
From heredity to simple cells
Authors: Maynard Smith John , SzathmáRy EöRs
Published: November 2023

The scenario we outlined in the last chapter for the origin of the code assumed co-operative interactions between replicators. For example, one ribozyme functioned to produce a cofactor that would increase the efficiency of a second ribozyme. Even if this particular hypothesis turns out to be mistaken, it is clear that, for life to progress beyond the stage of simple replicating molecules to something more complex, a web of co-operative interactions between genes had to evolve. In this chapter we discuss how this could have happened.
Genetic conflict
Authors: Maynard Smith John , SzathmáRy EöRs
Published: November 2023

The kinds of problem we have pointed to when discussing the major transitions can be observed in present-day organisms. In this chapter and the next, we pause in our chronicle of these transitions to look at examples of conflict and co-operation that can be studied today. We hope in this way to add some realism to the suggestions we have made. In particular, we want to show how difficult it may be to eliminate conflict between replicators within an organism, and yet that remarkable examples of co-operation do in fact exist. In this chapter we describe the conflicts of interest that can arise between genes, or groups of genes, present in the same organism, or in closely related organisms. In the next chapter we discuss examples of co-operation between organisms with different evolutionary histories.
The origin of language
Authors: Maynard Smith John , SzathmáRy EöRs
Published: November 2023

It is impossible to imagine our society without language. The society we live in, day and night, depends on it. Even as we sleep, information about us is being stored, and maybe processed. Imagine that we apply for a job on the other side of the world. We are confident, or at least we hope, that our application will be fairly treated, and that the country to which we would like to move is running properly; that is, that social contracts are observed. Our lives depend on the social division of labour, and on detailed social contracts, which could not exist without language. No ape or dolphin could comprehend, even in spoken form, a contract for a job.
The amygdala-what’s happened in the last decade?
Authors: Aggleton John P , Saunders Richard C
Published: November 2023

Research on the amygdala has more than doubled in the last decade. During that time, new techniques and new questions have had a considerable impact on our understanding of this structure. A dominant theme has been the convergence of findings from studies of rodents and studies of primates, including humans. This has been aided by advances in brain imaging and the discovery of specific cognitive deficits that accompany amygdala damage in humans. These advances are now making it possible to appreciate the likely contribution of the amygdala to various psychopathologies, including schizophrenia, that affect emotional and social behaviour. This review also considers in detail the contributions of the amygdala tool factory processes as they highlight the diversity of functions associated with this structure.
Amygdala and the memory of reward: the importance of fibres of passage from the basal forebrain
Authors: Easton Alexander , Gaffan David
Published: November 2023

The understanding of the role played by the amygdala in the memory of reward has changed substantially in the years since the review of Gaffan (1992) in the previous edition of this book. It appeared from the data available at that time that the amygdala played a crucial part in the association of stimuli with the value of reward. As discussed here, this view has been changed by the use of excitotoxins in lesioning the amygdala, which have shown that the effects discussed previously are dependent mainly on fibers of passage through the amygdala. In particular, we will argue that fibers of passage from the basal forebrain through the amygdala are crucial for the reinforcement of visual learning.
Emotion recognition and the human amygdala
Authors: Adolphs Ralph , Tranel Daniel
Published: November 2023

We have conducted a systematic series of investigations aimed at understanding the role of the human amygdala in processing emotion, by studying a rare individual (subject S.M.) with selective bilateral damage to the amygdala. We assessed S.M.’s ability to recognize emotions in facial expressions, lexical stimuli, and auditory stimuli on a variety of tasks that investigated naming, recognition, and categorization. Many of these findings have now been replicated in additional subjects with bilateral amygdala lesions, from both our laboratory and those of others. Also, functional imaging studies in normal subjects have begun to provide convergent results. This chapter provides a comprehensive review of recent findings regarding the role of the human amygdala in recognition of emotion, focusing in particular on the experiments we have conducted with S.M.
Functional neuroimaging of the human amygdala during emotional processing and learning
Authors: Dolan Raymond J
Published: November 2023

The functions of the amygdala traditionally have been studied using animal models or reports on patients with focal lesions. Functional neuroimaging techniques, such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), now provide non-invasive tools to study human amygdala function in vivo. This chapter provides an account of recent studies on human amygdala function using neuroimaging techniques where the prime focus will be fear processing. These studies highlight a key role for the amygdala during the perception of fear and in fear-related learning. Two striking observations emerge from these studies. First, activation of amygdala does not depend on conscious awareness of a fear-eliciting stimulus. Secondly, during fear learning, using classical Pavlovian conditioning, the amygdala’s role would seem to be time limited.
Myosin structure
Authors: Sellers James R
Published: November 2023

There are now several three-dimensional structures for various myosin fragments, including that of chicken fast skeletal muscle S-1 containing both light chains [366], several motor domains of Dicryostelium myosin II with various bound nucleotides [155,223,235,385,386], and the neck region or regulatory domain of scallop myosin [267,460]. The protein used for the Dicryostelium crystals was truncated at amino 761 and did not contain light chains. Preliminary data has been presented on two nucleotide-containing smooth muscle crystals that contain the motor domain and the essential light chain [211]. Most of the ensuing discussion is derived from these papers and from three recent reviews [55,92,93]. As each structure is discussed, the amino acid numbering system for that particular myosin will be used. Thus, the first part of this discussion will use numbers derived from the sequence of chicken fast skeletal muscle myosin. See Fig. 12 for an alignment of the primary sequence of chicken skeletal muscle, chicken smooth muscle, scallop striated muscle myosin, and Dicryostelium nonmuscle myosin.
Functional properties of myosin
Authors: Sellers James R
Published: November 2023

Myosin is an enzyme that catalyses the hydrolysis of MgATP to produce mechanical work. The intact myosin molecule is not well suited for either steady state or transient kinetic studies of the MgATPase activity, particularly when conducted in the presence of actin since it polymerizes into thick filaments at physiological and lower ionic strengths. These filaments do not mix well, tend to settle to the bottom of reaction vials during long time courses, scatter large amounts of light (which interferes with spectroscopic measurements), and interact heterogeneously with actin filaments. Therefore, most of the information on the kinetic cycle has been gleaned from studies with the soluble fragments, S-1 or HMM (Fig-7).
Theoretical aspects of Nedelec’s edge elements applied to electromagnetic problems
Authors: Kikuchi Fumio
Published: November 2023

Numerical analysis of electromagnetic problems is now quite important in wide fields of science and engineering. The application of the finite element method (FEM) to such ends is expected to be very effective especially for 3-D problems since FEM is well suited to deal with complex regions and various boundary conditions. By appropriate modeling of the Maxwell equations of electromagnetics, we have various problems describing electromagnetic phenomena in practice.
Vortex structures in turbulent flow
Authors: Moffatt H K
Published: November 2023

It is an honour to be invited to lecture in this magnificent hall of the University of Edinburgh, where I was privileged to study mathematics and physics in the great era of Aitken, Edge, Schlapp, Kemmer and Nisbet. I matriculated here in 1953. Although I didn’t realise it at the time, this was a significant year for the subject of Turbulence: it was the year in which the research monograph ‘Homogeneous Turbulence’ by George Batchelor, my future research supervisor in Cambridge, was published. This set out the mathematical tools for the study of turbulence in an extraordinarily clear and perceptive manner, and defined with equal clarity the nature of the dynamical problem that had to be solved. There was a degree of optimism in the 1950s that a closure scheme known as the quasi-normal approximation (or zero 4th cumulants) would provide the essential key to this solution. By 1960, this optimism had begun to fade and it became increasingly clear that the central dynamical problem of turbulence was unlikely to yield to any closure scheme that was simple enough to be useful in meteoro logical and engineering applications.
Domain decon1position for Navier-Stokes equations
Authors: Moran Bill , Avdonin Sergei
Published: November 2023

It is common place to recall that microprocessors are doubling their computing power roughly every two years. But even so, there are a few very important fields of physics which are out of reach computationally; turbulence is one of them. Therefore, it is tempting to cluster computers (see for example the Beowulf projects) to increase the computing resources for a single task. This can be done either by the user or by the computer manufacturer.
Boundary Conditions and the Attenuation of Waves in Deformable Tubes
Authors: Gerrard J H
Published: November 2023

The standard Womersley theory for pulsatile flow in distensible tubes is outlined with entension to walls which are not infinitesimally thin and which are viscoelastic. In general there are two waves types, one in which the wall motion is principally radial (waves 1) and those in which the motion is principally longitudinal (waves 2). When the oscillating motion is produced by a piston driving one end of the tube it is found that waves 1 are first produced and these produce waves 2. The possibility of each wave type producing the other is discussed. Waves 2 appear not to be found in cardiovasculcar systems. My subject is fluid mechanics. In 1965 I became interested in cardiovascular flow having heard some lectures on the subject. There used to be a Medical Engineering Club in Manchester at which liaison between scientists and clinicians was encouraged. I did a little work with Derek Rowlands at the Manchester Royal Infirmary and later Professor David Charlesworth and I got together at the University Hospital of South Manchester in Withington. He had a well equipped laboratory in which we looked at pulsatile flow in latex tubes. This has been followed by many years of collaboration. Our latest interest has been in atherogenesis. At this meeting it does not need to be stressed that collaboration between scientists and clinicians is a vital constituent for progress.
Study of Newtonian and Non-Newtonian Fluid Flow in a Channel with a Moving Indentation
Authors: Neofitou P , Drikakis D , Leschziner M A
Published: November 2023

In the context of bio-fluid mechanics, the study of unsteady flow in channels with moving boundaries is largely motivated by the need to understand biological flows in collapsible tubes such as arteries and veins. Since in vivo arterial flows involve many physical issues which need to be modelled, simpler geometrical models are usually employed which, however, reproduce many of the important phenomena occuring in the real flow, such as unsteadiness, moving walls, separation and propagation of vorticity waves. Such a model is the flow in a channel with a moving indentation in one wall [1, 2]. Pedley and his co-workers have in the past studied, both experimentally and computationally, the flow down stream of a laterally moving indentation focusing especially on the generation and propagation of wave crests. The above flow was considered in the present study as a basis for validating our numerical model which is based on the Navier-Stokes equations in generalised curvilinear co-ordinates in conjunction with the space conservation law for the case of moving, compressing grids.
Modelling of Flow Transport in Arteries
Authors: Doorly D J
Published: November 2023

Computational procedures to model transport processes in large arteries are described. The procedures are based on hybrid Eulerian-Lagrangian techniques, in which the velocity field represented on a fixed Eulerian mesh is used to compute the trajectories of marker particles. Applications to the modelling of high Peclet number convection-diffusion and shear-induced damage are described. Extension of the procedure to enable numerical computation of magnetic resonance images of flow in arteries is briefly outlined. By using a suspension of particles in a fluid (i.e. blood) which is forced around the body by the heart, convection becomes responsible for transport over large distances thus overcoming the limitations of diffusion. Although convection is the dominant means of transport within the large arteries, even here diffusion plays an important role, particularly in the flow near the vessel walls. Blood is a complex fluid, comprising a suspension of particles (the formed elements: erythrocytes, leukocytes and platelets) in plasma. Detailed modelling of the dynamics of the particles in the flow will not however be considered here. Instead the particles will be idealised as being of infinitesimal size and of neutral buoyancy. We do not consider turbulent flows since for the most part the flow in arteries remains laminar, although it may be highly disturbed.
The Numerical Investigation of a Novel Haemodynamic Control Device which Reduces the Development of Occlusive Arterial Intimal Hyperplasia
Authors: O’Reilly* M J G
Published: November 2023

A computational fluid dynamics investigation of the pulsatile, non Newtonian blood flow through a typical, three-dimensional model of a human femorodistal bypass graft has emphasised the complicated temporal and spatial dependence of the flow patterns at the proximal and distal anastomoses. A novel, simply configured Haemodynamic Control Device (HCD), fit ted at the ends of the graft, judiciously modified the anastomotic flow fields. Flow separation and recirculation were diminished. It is believed that the successful optimisation of the HCD would have important benefits for vascular bypass patients since the inhibiting of the unnatural, disturbed haemodynamics should mean that the development of intimal hyperplasia, and eventual graft failure, is less likely. The bypassing of critically stenosed arteries using biological or synthetic grafts is a common surgical procedure for alleviating life-threatening angina or limb threatening ischaemia. However, intimal hyperplasia, the progressive, abnormal proliferation of the innermost layer of the arterial wall, is a major cause of the early and medium term failure of bypass grafts [I]. It is known that intimal hyperplasia develops exclusively at the suture line where the graft is surgically attached to the host artery, and on the floor of the host artery opposite the anastomosis [2]. The disease occurs predominantly at the distal rather than the proximal anastomosis, with prosthetic grafts being at greater risk than biological grafts. Figure 1 outlines a typical vascular bypass configuration with the observed distribution of anastomotic intimal hyperplasia.
Rouleaux Formation; its Causes and Consequences
Authors: Rampling M W
Published: November 2023

Human erythrocytes in whole blood have a natural tendency to ad here together to form aggregates with characteristic morphology known as rouleaux. The ultimate cause of this phenomenon is the presence in the plasma of large plasma proteins, especially fibrinogen. Because the concentrations of these proteins increase in association with many clinical conditions, the degree of aggregation also increases in these conditions, examples of which are diabetes, hypertension, post-surgery and pregnancy. From a rheological point of view the interest in rouleaux formation is largely due to its being the major factor responsible for the remarkable shear dependence of blood viscosity. While much is already known about rouleaux formation, there are two areas that are still little understood. Rouleaux formation is the loose aggregation of red cells that occurs in most human blood when left for a time in stasis. The aggregates have a characteristic morphology with the cells adherent face-to-face to produce columns of cells similar to piles of coins. The forces leading to aggregation are weak, so if a sample of normal blood is put into a couette viscometer and subjected to increasing shear rate the aggregates progressively break up until at excess of about 10 s-1 the aggregates are generally monodispersed.
Elementary Intuitionistic Mathematics
Authors: Dummett Michael
Published: November 2023

The name ‘intuitionism’ is due to Brouwer’s acceptance of the Kantian thesis that our concept of the natural number series is derived from temporal intuition, our apprehension of the passage of time; not, indeed, from any particular details of our experience, but from the a priori form of that experience as involving temporal succession.
I Wish I’d Made You Angry Earlier
Authors: Perutz Max F
Published: November 2023

Science is no quiet life. Imagination, creativity, ambition, and conflict are as vital and abundant in science as in artistic endeavours. In this collection of essays, Nobel Laureate Max Perutz explores a remarkable range of scientific topics with the lucidity and precision that he brought to his pioneering work in protein chemistry. His book includes detective stories, tales of conflict and battle, one woman's love affair with crystals, a man's gruesome fascination with poison gas, the phantom perils that have been conquered by silent heroes. Perutz argues that science is a passionate exercise and that the pursuit of knowledge is a sortie into the unknown. The pages of this book are populated with some of the intellectual giants of twentieth century science - Pauling, Meitner, Medawar, Krebs, and Jacob, among others. In addition, Perutz's own life provides entertaining anecdotes, including his internment in the UK as an anemy alien, his involvement in a scheme to make ships of ice for refuelling aircraft in the North Atlantic during the War, and the sheer joy he took from his work. 'This....Is a wholly captivating book; it has warmth, wit, and style, and not a dull sentence. I urge you to read, enjoy, and learn.' Walter Gratzer, Nature
The Forgotten Plague*
Authors: Perutz Max F
Published: November 2023

What did Cardinal Richelieu, Heinrich Heine, Frederic Chopin, Anton Chekhov, Franz Kafka, George Orwell, and Eleanor Roosevelt have in common? They all died of tuberculosis because the treatments available until about fifty years ago did little to prolong sufferers’ lives. Ryan’s story of the discovery of the antibiotics and other agents used against tuberculosis makes as exciting reading as Paul de Kruif’s Microbe Hunters, which must have lured more idealistic young people into medical research than any other book ever written. In earlier times, a clean, mild climate was often prescribed, but Chopin wrote ruefully from his villa in Mallorca:
Big Fleas Have Little Fleas …*
Authors: Perutz Max F
Published: November 2023

The early conceptual development of molecular biology was dominated by two physicists: Max Delbrück and Francis Crick. Both owe their fame to a small number of seminal papers and their influence to their formidable powers of imagination and argument. Delbrück began his scientific career with Otto Hahn and Lise Meitner, who engaged him as a theoretician to help them interpret their bombardment of uranium with neutrons.
The Second Secret of Life
Authors: Perutz Max F
Published: November 2023

In 1937,1 chose hemoglobin as the protein whose structure I wanted to solve, but it proved so much more complex than any solved before that it eluded me for more than 20 years. First success came in 1959, when Ann F. Cullis, Hilary Muirhead, Michael G. Rossmann, Tony C.T. North, and I first unraveled the architecture of the hemoglobin molecule in outline. We felt like explorers who have discovered a new continent, but it was not the end of the voyage, because our much-admired model did not reveal its inner workings —it provided no hint about the molecular mechanism of respiratory transport.
From Kant to Hilbert: A Source Book in the Foundations of Mathematics
Authors: Ewald William
Published: November 2023

Immanuel Kant's Critique of Pure Reason is widely taken to be the starting point of the modern period of mathematics while David Hilbert was the last great mainstream mathematician to pursue important nineteenth cnetury ideas. This two-volume work provides an overview of this important era of mathematical research through a carefully chosen selection of articles. They provide an insight into the foundations of each of the main branches of mathematics--algebra, geometry, number theory, analysis, logic and set theory--with narratives to show how they are linked. Classic works by Bolzano, Riemann, Hamilton, Dedekind, and Poincare are reproduced in reliable translations and many selections from writers such as Gauss, Cantor, Kronecker and Zermelo are here translated for the first time. The collection is an invaluable source for anyone wishing to gain an understanding of the foundation of modern mathematics.
Augustus De Morgan (1806-1871)
Authors: Ewald William
Published: November 2023

We have seen above that in the eighteenth and early nineteenth centuries many central mathematical problems-the justification of the calculus, the status of the axioms.
James Joseph Sylvester (1814-1897)
Authors: Ewald William
Published: November 2023

Sylvester was educated at the University of London (later University College, London), at Trinity College, Dublin, and at St John’s College, Cambridge. He had a chequered career. From 1838 to 1841 he was a colleague of De Morgan’s at University College, London.
Charles Sanders Peirce (1839-1914)
Authors: Ewald William
Published: November 2023

Near the end of his strange and beleaguered life, shortly after the death of his friend William James, C.S. Peirce despairingly wrote: ‘Who could be of a nature so different from his as I? He so concrete, so living; I a mere table of contents, so abstract, a very snarl of twine’ (Peirce 1931-58, Vol. vi, p. 131.)
The Statistical Mechanics of Interacting Walks, Polygons, Animals and Vesicles
Authors: Janse van Rensburg E J
Published: November 2023

This book surveys and explains the mathematical methods and techniques used in the study of lattice models of polymers in solvents. The techniques include the self-avoiding walk and its related models including animal and tree graphs, surfaces and vesicles. The important feature in all these models in the contribution of conformational degrees of freedom to the free energy, and this leads on to the idea of a tri-critical point. The book explores the theory of tri-criticality showing how it can be used to interpret the limiting free energy and generating functions. Density function and pattern theorems are also discussed and finally these ideas are applied to models of collapsing and adsorbing walks, to composite polygons and crumpling surfaces.
Linear Second-Order Odes With Polynomial Coefficients
Authors: Slavyanov Sergei yu. , Lay Wolfgang , Seeger Alfred
Published: November 2023

The starting point and the major object of study of this book is the ordinary linear homogeneous second-order differential equation

with polynomial coefficients P0(z), P1 (z), P2(z) considered in the complex z plane. The primes in (1.1.1) indicate differentiation with respect to z. It is supposed that the polynomials in (1.1.1) do not possess common factors depending on z. The degrees of the polynomials P0, P1, P2 are denoted by k0, k1, k2. Beyond the z plane as the range of definition for eqn (1.1.1), the Riemann sphere can be considered. This al1ows us to incJude the point z = ∞ in our studies. The complex z plane including the point z ∞ is denoted by ℂ. Equation (1 .1.1) has two linearly independent solutions. The general solution of eqn (1.1.1) is an arbitrary linear combination of these particular solutions.
Electromagnetic Theory
Authors: Kovetz Attay
Published: November 2023

This textbook is intended for undergraduate and graduate students taking an intermediate or advanced course in electromagnetism. It presents electromagnetism as a classical theory, based, like mechanics, on principles that are independent of the atomic constitution of matter. This book is unique amongst electrodynamics texts in its treatment of the precise manner in which electromagnetism is linked to mechanics and thermodynamics. Thus a clear distinction is maintained between such concepts as field and force, or radiation and heat. Applications include radiation from charged particles, electromagnetic wave propagation and guided waves, thermoelectricity, magnetohydrodynamics, piezoelectricity, ferroelectricity, paramagnetic cooling, ferromagnetism and superconductivity. There are 225 worked examples of dynamical and thermal effects of electromagnetic fields, and of effects resulting from the motion of bodies. The concise, methodological approach of this book will be valuable to students and will make it of special interest to tutors and lecturers.