bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetism in Condensed Matter
Authors: Blundell Stephen
Published: November 2023

An understanding of the quantum mechanical nature of magnetism has led to the development of new magnetic materials which are used as permanent magnets, sensors, and in information storage. Behind these practical applications lie a range of fundamental ideas, including symmetry breaking, order parameters, excitations, frustration, and reduced dimensionality. This superb new textbook presents a logical account of these ideas, starting from basic concepts in electromagnetism and quantum mechanics. It outlines the origin of magnetic moments in atoms and how these moments can be affected by their local environment inside a crystal. The different types of interactions which can be present between magnetic moments are described. The final chapters of the book are devoted to the magnetic properties of metals, and to the complex behaviour which can occur when competing magnetic interactions are present and/or the system has a reduced dimensionality. Throughout the text, the theoretical principles are applied to real systems. There is substantial discussion of experimental techniques and current research topics. The book is copiously illustrated and contains detailed appendices which cover the fundamental principles.
Order and magnetic structures
Authors: Blundell Stephen
Published: November 2023

In the previous chapter the different types of magnetic interaction which operate between magnetic moments in a solid have been presented. In this chapter we will consider the different types of magnetic ground state which can be produced by these interactions. Some of these ground states are illustrated in Fig. 5.1. The different ground states include ferromagnets in which all the magnetic moments are in parallel alignment, antiferromagnets in which adjacent magnetic moments lie in antiparallel alignment, spiral and helical structures in which the direction of the magnetic moment precesses around a cone or a circle as one moves from one site to the next, and spin glasses in which the magnetic moments lie in frozen random arrangements. This chapter will be concerned with showing how, in broad terms, the interactions discussed in the previous chapter lead to these differing ground states. In the following chapter the phenomenon of order will be examined in a more general context and it will be seen that order is a consequence of broken symmetry.
Renormalization group
Authors: Cheng Ta-Pei , Li Ling-Fong
Published: November 2023

This means that a heavy fermion will decouple in the vacuum polarization at energies much smaller than the heavy fermion mass. This property will enable us to ignore all the unknown particles which are much heavier than the present energies.
Chiral symmetry
Authors: Cheng Ta-Pei , Li Ling-Fong
Published: November 2023

By comparing these results with the eqns (5.54) and (5.58) obtained in Part (a), we note that these charge-field commutators just yield the variation of the field under the isospin transformation with some parameter α i-:
Gauge symmetries
Authors: Cheng Ta-Pei , Li Ling-Fong
Published: November 2023

But this extra term is of the same form but of opposite sign so as to cancel the corresponding term in the transformation of the ordinary derivative. In this way the gauge field is just the compensating field needed to enforce the invariance of the theory under transformations that differ from point to point.
Grand unification
Authors: Cheng Ta-Pei , Li Ling-Fong
Published: November 2023

Namely, the single SU(5) representation having exactly the same number of states (with the correct quantum numbers) as one generation of standard model fermions clearly does not correspond to any particles we have observed so far:
Pulse eldor and related experiments
Authors: Schweiger Arthur , Jeschke Gunnar
Published: November 2023

Many EPR experiments require larger excitation bandwidths than can be realized with pulses at a single frequency. For example, if cross-relaxation processes transfer non-equilibrium magnetization to transitions outside the excitation window, only a loss of magnetization at the observer position is noticed. Cross relaxation then cannot be distinguished from other relaxation processes and we cannot establish which cross-relaxation pathways are significant. Molecular reorientations may also shift a transition frequency out of the window in which spins can be excited and detected, so that information regarding the type of the reorientation process is lost. Furthermore, couplings between electron spins can only be detected if the two spins are excited in the same experiment. Such measurements are of particular interest since the dipolar coupling between two electron spins is related to their distance.
Transient nutation techniques
Authors: Schweiger Arthur , Jeschke Gunnar
Published: November 2023

We have seen in Chapter 3 that not only the transition frequencies but also the transition amplitudes depend on the parameters of the spin Hamiltonian. The transition amplitudes can thus be used to determine these parameters. They quantify the strength of the interaction of the radiation field with a transition and can in principle be measured by the transient nutation experiment introduced in Chapter 7. In this chapter we first discuss the complications which arise in multi-level systems due to the mixing of more than two levels by strong irradiation. In such cases the nutation frequencies are no longer proportional to transition amplitudes, rather they have to be considered as transition frequencies of a dressed spin in analogy to the concept of dressed states in coherent optic We then introduce three methods for the observation of nutation frequencies and explain in detail how information on spin quantum numbers, the magnetic quantum numbers associated with the observed transition, and g values can be obtained from the nutation frequencies. Finally we present several pulse sequences and examples for their application. Special emphasis is given to the application of transient nutation experiments to short-lived paramagnetic species. These experiments provide a high time resolution and information about the coupling of electron spins in radical pairs as well as about nuclear frequencies.
Antioxidant intervention studies in animals
Authors: Pettersson Knut S , Witting Paul K , Stocker Roland
Published: November 2023

The pathology of atherosclerosis is multi-factorial, with several risk factors affecting the likelihood and severity of the disease. Recently, much attention has been placed on oxidation of low-density lipoprotein (LDL) as an early event in the development of the disease. Oxidative modification of LDL is known to change the LDL particle into a more atherogenic type than native LDL.(l) Shortly after it was reported that the lipid-lowering agent probucol could protect LDL from becoming oxidized in vitro,(2) it was also shown that this agent can protect LDL receptor-deficient rabbits against atherosclerotic lesion development<3- 4) independent of its lipid-lowering effect.<3) This finding was the most prominent experimental support for the ‘oxidation theory’ of atherogenesis.<(l)
Vascular dysfunction and its contribution to atherogenesis
Authors: Celermajer David S , Vita Joseph A
Published: November 2023

Traditionally, attention in atherosclerosis research and clinical practice has focused on vascular structure - plaque size and composition - with particular regard to the degree of arterial obstruction. In recent years, however, there has been a realization that vessels are dynamic, especially at the sites of plaque. Further narrowing in response to exercise and mental stress, for example, may underlie many episodes of ischemia and even acute coronary syndromes.
Gene therapy for vascular diseases: closer to delivering the goods?
Authors: Rasko John E J , Celermajer David S
Published: November 2023

The excitement surrounding the potential application of gene therapy to cardiovascular disease has been sustained since the first in vivo animal trials were published in 1990. The ideas and techniques of gene therapy build on some of the most important scientific advances of the twentieth century - molecular biology and the human genome project. However, despite steady progress, the promises of gene therapy have not yet been realized.
The endothelial cell in atherosclerosis
Authors: Bannon Paul , James Natalie , Jessup Wendy
Published: November 2023

Originally blood vessels were viewed as simple conduits, regulated at a distance by circulating hormones and the sympathetic nervous system. This view has now greatly expanded to recognize the central role of endothelial cells as active participants in vascular function. Endothelial cells form a continuous single-cell-thick layer lining blood vessels of the entire vascular tree, located between the circulating blood and the underlying vascular cells and tissues. As such, it is an important interface which controls the passage of molecules and cells and participates in signal transduction.
Macrophage lipid metabolism and atherosclerosis
Authors: Kritharides Leonard , Jessup Wendy
Published: November 2023

Atherosclerotic lesion development is preceded by intimal penetration of blood borne mononuclear cells which subsequently undergo transformation into macrophage foam cells in fatty streak lesions.< The macrophage is an early and persistent feature of atherosclerosis and is therefore likely to be pivotal in the disase development. Indeed, the importance of the macrophage in atherosclerosis was revealed in the osteopetrotic (op) mouse (lacking macrophage colony-stimulating factor (M-CSF) and thus severely deficient in monocytes) in which a profound inhibition of atherosclerosis development was observed.(2)
Smooth muscle cells and the connective tissue matrix of the intima
Authors: Campbell Gordon R , Bingley John A , Hayward Ian P , Campbell Julie H
Published: November 2023

Diffuse intimal thickenings in large and medium-sized arteries are sites for the development of atherosclerosis. For the first one to two decades in most humans, the thickening is composed of smooth muscle cells completely surrounded by extracellular matrix and covered by an endothelium. Occasionally, isolated macrophages are observed beneath this endothelium layer. The extracellular matrix provides two primary functions for cells: (i) it maintains the spatial relationships between cells; and maintains their differentiated state. In this context, it is intriguing to consider the fact that most of the extracellular matrix in the human intimal thickening is synthesized by the smooth muscle cells themselves. The consequences of this relationship mean that if under pathological circumstances there is a change in the function of either the smooth muscle cells or the extracellular matrix, then one could expect a concomitant change in the other component.
Some basic concepts
Authors: Severini Thomas A
Published: November 2023

The purpose of this chapter is to review some basic concepts of probability and statistics that will play a central role in the subsequent chapters, as well as to introduce some notation and terminology.In statistical inference observational or experimental data are modeled as the observed values of certain random variables. Let Y denote a random variable with density function p(y); here the term ‘density function’ will be used to mean a density function with respect to either Lebesgue measure or counting measure.
Large-sample approximations
Authors: Severini Thomas A
Published: November 2023

In many cases it is difficult or impossible to find the exact sampling distribution of a statistic. In these cases, we may use a large-sample approximation. Let Y  1,..., Y  n denote a sequence of real-valued random variables and let F  n denote the distribution function of y  n. Consider the problem of approximating F  n. In typical applications, n denotes the underlying sample size so that, for example, Y  n may be the sample mean based on n independent observations.
Asymptotic theory and conditional inference
Authors: Severini Thomas A
Published: November 2023

The asymptotic theory developed in the preceding sections was concerned with the marginal distributions of various likelihood-based quantities. In this chapter we consider the conditional distributions of likelihood-based quantities given an ancillary statistic.There are at least two motivations for such conditioning. One is that, by keeping certain functions of the underlying random variable fixed at their observed values, it makes the probability calculations more relevant to the data at hand; this is discussed in Section 1.6 and illustrated in Example 1.23.
The modified profile likelihood function
Authors: Severini Thomas A
Published: November 2023

In Chapter 8 it was shown that, in some cases, inference about a parameter of interest ψ may be based on a marginal or conditional likelihood function. Those methods are only available however when the model has a particular structure. Furthermore, even when a marginal or conditional likelihood function exists, calculation of the likelihood function is often difficult.In this chapter, we consider the modified profile likelihood, a pseudo-likelihood function that is available for general models. The modified profile likelihood may be derived as an approximation to either a marginal or conditional likelihood when either of those likelihoods exists. Furthermore, the calculation of the modified profile likelihood function does not require the existence of a marginal or conditional likelihood and, hence, it has been adopted for general use.
Measurements in flat space–times
Authors: Ellis George F R , Williams Ruth M , Carfora Mauro
Published: November 2023

We shall now make quantitative the properties of the space-time of special relativity introduced in the previous chapters. To do so we shall use a simple formalism introduced by Herman Bondi, called the A’-calculus. We can represent faithfully all physical effects in these flat space-times, except gravity.
The Lorentz transformation and the invariant interval
Authors: Ellis George F R , Williams Ruth M , Carfora Mauro
Published: November 2023

Some people would claim that man’s destiny, if he does not destroy himself before he has time to attain it, is to explore the Galaxy. As always, in venturing into the unknown, accurate surveying and mapping will be of vital importance for the safety of those engaged in this enterprise. Thus, it will be necessary to collate observations from many observatories.
Spherical stars and stellar collapse
Authors: Ellis George F R , Williams Ruth M , Carfora Mauro
Published: November 2023

In this chapter, we are concerned with two problems of astrophysical importance: firstly, the description of the gravitational field of the Sun, which dominates the dynamics of the solar system; and secondly the issue of the nature of the gravitational field of a massive star, and how stellar collapse takes place leading to the formation of a ‘black hole’. The analysis of these topics is based on an exact solution of Einstein’s field equations, the Schwarzschild solution (discovered by Karl Schwarzschild in 1917, shortly before his death in the First World War).
Finale
Authors: Ellis George F R , Williams Ruth M , Carfora Mauro
Published: November 2023

The content of relativity theory is very surprising. It is an example of the hidden nature of reality - namely, the true way things are is not at all obvious; but we can find it out if we investigate carefully enough. Indeed relativity theory is a classic case of the counter-intuitive nature of physics. The major such features in fundamental physics are Newtonian theory, special relativity, quantum theory, and general relativity (together with a feature of somewhat different character: its capacity to create self-organizing structures). In each case it has taken the best and most creative scientists to break out of the ‘obvious’ mould and determine the true pattern that underlies the regularities of nature (see Lewis Wolpert: The Unnatural Nature of Science (Faber, London, 1992) for further discussion).
How to measure dispersal: the genetic approach. The example of fire ants
Authors: Ross Kenneth G
Published: November 2023

Dispersal and gene flow were studied in the fire ant Solenopsis invicta by combining population genetic analyses and natural history information. In introduced and native populations of this ant, local genetic structure is evident in the polygyne social form (multiple queens per nest) but not the monogyne form (single queen per nest), a pattern particularly evident for the mitochondrial DNA (mtDNA).
Dispersal in pikas (Ochotona princeps): combining genetic and demographic approaches to reveal spatial and temporal patterns
Authors: Peacock Mary M , Ray Chris
Published: November 2023

Demographic studies of dispersal lack the spatial and temporal breadth necessary to characterize the full patterns of movement, settlement and mating within and between populations. Genetic studies can provide some of these missing data on mating patterns and gene flow, allowing us to address certain evolutionary questions. However, genetic inference of dispersal is not yet an exact science, and there is no one-to-one correspondence between patterns of gene flow and dispersal. In order to determine the details of dispersal, it is useful to use demographic data to guide genetic inference. This paper uses dispersal data from a small, territorial lagomorph to explore several examples of the potential interplay between genetic and demographic data, from pattern detection through hypothesis testing.
Dispersal, intraspecific competition, kin competition and kin facilitation: a review of the empirical evidence
Authors: Lambin Xavier , Aars Jon , Piertney Stuart B
Published: November 2023

Theory suggests that intraspecific competition and kin competition are keys processes shaping the evolution of dispersal. Based on a review of the empirical literature we derived the following generalizations. The plasticity within taxa in the presence and direction of sex-biased dispersal revealed by recent empirical studies argues against a single factor accounting for interspecific patterns in dispersal. If they can be parameterized, models exploring the interactions between competitive interaction and inbreeding avoidance will provide rigorous predictions for different groups.
Parasitism and predation as causes of dispersal
Authors: Weisser Wolfgang W , McCoy Karen D , Boulinier Thierry
Published: November 2023

In the past 30 years, much theoretical and empirical work has been devoted to exploring the relationship between intraspecific interactions and dispersal. As a consequence, kin competition, inbreeding, and demography have been shown to be major factors in the evolution of dispersal (see Gandon and Michalakis, chapter 11; Ronce et al., chapter 24; Perrin and Goudet, chapter 9).
T’he genetic basis of dispersal and migration, and its consequences for the evolution of correlated traits
Authors: Roff Derek A , Fairbairn Daphne J
Published: November 2023

‘Dispersal and migration’ cannot be considered a single trait: it comprises physiological, morphological, behavioural, and life history components, all contributing to the probability that an organism will move from one location to another. Furthermore, traits that form the suite of ‘migration’ characters may themselves influence other fitness-related traits.
Formal Description of Crystal Structures
Authors: Dove Martin T
Published: November 2023

In earlier chapters we met some of the fundamental concepts involved in describing crystal structures, but only in a case-by-case way. The purpose of this chapter is to properly formalize the description of crystal structures. Formalism can be like reading the instructions that go with a new gadget – it is nice to avoid reading them when starting out, but eventually there are many good reasons for studying them in detail. We can get quite far in our study of crystalline materials without worrying too much about the details of the formalism, but eventually the power behind the formalism makes it sensible to come to terms with it. So the reader should feel free to skip over this chapter when first approaching the study of crystalline materials, but bookmark it for future reference when there is a need to grasp some of the finer details needed to appreciate the arguments used in the deeper applications of the subject.
Experimental Methods for Measurements of Vibrational Frequencies
Authors: Dove Martin T
Published: November 2023

The main experimental approach to study the structure of materials is through scattering of radiation, as was discussed in some depth in Chapter 6. It was noted that several different types of radiation beams can be used in diffraction, including electromagnetic radiation and beams of neutrons, each with its own relative merits. It is not surprising that scattering of radiation also proves to be one of the main techniques for studying dynamics. Nor is it surprising that, like in structural studies, there are several types of radiation that can be used, with each radiation type giving complementary information. Our purpose in this chapter is to review the various spectroscopic techniques that are in common use for the study of dynamic processes in solids.
Renormalization Methods
Authors: McComb W D
Published: November 2023

This book is unique in occupying a gap between standard undergraduate texts and more advanced texts on quantum field theory. It covers a range of renormalization methods with a clear physical interpretation (and motivation), including mean-field theories and high-temperature and low-density expansions. It then proceeds by easy steps to the famous epsilon-expansion, ending up with the first-order corrections to critical exponents beyond mean-field theory. Nowadays there is widespread interest in applications of renormalization methods to various topics ranging over soft condensed matter, engineering dynamics, traffic queueing and fluctuations in the stock market. Hence macroscopic systems are also included, with particular emphasis on the archetypal problem of fluid turbulence. The book is also unique in making this material accessible to readers other than theoretical physicists, as it requires only the basic physics and mathematics which should be known to most scientists, engineers and mathematicians.
This Taint of Blood
Authors: Nettle Daniel
Published: November 2023

The evidence reviewed at the end of the previous chapter all pointed strongly to a role for hereditary factors in psychosis. This would seem to add madness to that long list of medical conditions for which particular genes are implicated. Our understanding of the genetics of diseases is currently advancing at a staggering pace. It is not just that we know the patterns of transmission that can occur; these have been understood at a theoretical level for over 100 years, ever since Gregor Mendel performed his famous experiments on the proportions of different flower types in hybrid peas. The cur rent revolution is different. We now know the structure of DNA itself, and have cracked the code in which its instructions to body cells are written. We also have, admittedly indirect but none the less astounding, techniques for reading sequences of DNA from the chromosomes of living individuals. Thus, for hereditary diseases, we can now go hunting for the actual gene involved, and, having found it, establish how it does its work.
The Sleep of Reason Produces Monsters
Authors: Nettle Daniel
Published: November 2023

Should I let anyone know that there are moments in the schizophrenia that are ‘special’? Where there’s a different sort of vision allowed me? It’s as if … I’ve gone around the corner of humanity to witness another world where my seeing, hearing, and touching are intensified, and everything is a wonder … I won’t tell myself it’s all craziness.
Such tricks hath strong imagination
Authors: Nettle Daniel
Published: November 2023

If I have been doing my job well, the preceding chapters will have convinced you of four propositions. Firstly, psychosis is a reasonably common part of human experience, affecting something like 1 in 30 people in a typical population. Secondly, the major psychoses-schizophrenia and affective psychosis-consist of severe disruptions of cognition and emotion, which have a basis in the brain. Thirdly, the consequences of these disruptions are personally disastrous. They come on in the prime of life, and frequently lead to suicide, the loss of intimate relationships, and the loss of one’s capacity to provide for oneself. One can imagine no more severe impairment of social success than a major psychosis, short of actually dying. Fourthly, the liability to these disruptions is dependent on personality and, like other personality factors, it is substantially inherited in the genes.
Staying Sane
Authors: Nettle Daniel
Published: November 2023

Let me restate the genetic-creativity argument one final time. The major psychoses are basically genetic in origin, though the genetic liability may need triggering by unfavourable aspects of the environment. The genes that underlie psychosis affect the personality trait of psychoticism, by coding for aspects of brain chemistry and anatomy. These personality traits are not wholly negative. As well as madness, they are associated with great creativity. Great creativity is highly attractive, and so the traits, and the genetic variants behind them, persist in the gene pool.
Superconductivity, Superfluids, and Condensates
Authors: Annett James F
Published: November 2023

The book covers three main strands, Bose-Einstein condensates (BEC), superfluid and superconductivity. The subjects are developed in a way which gradually builds up the key concepts and the necessary mathematical machinery. The book begins with the simplest of the three topics, BEC, and first thoroughly reviews the basics of the Bose-Einstein ideal gas before going into the techniques of magnetic trapping and cooling of atoms and the discovery of BEC in dilute atomic gases. Superfluidity in helium-4 is more difficult to understand, because it is a strongly interacting quantum liquid. The book introduces the main physical phenomena of superfluidity, and how it follows from the key concept of macroscopic quantum coherence and off-diagonal long ranged order. The theory of superconductivity is developed in stages, starting with the simpler London and Ginzburg Landau theories and their main applications, before developing the mathematical concepts of a quantum coherent state and the Bardeen Cooper Schrieffer (BCS) theory. The final chapter deals with the more advanced topics, including superfluid helium-3 and evidence for unconventional Cooper pairing in exotic superconductors. No prior knowledge of quantum many-body theory is assumed, and the necessary mathematical concepts are introduced in a self-contained manner where needed.
Superconductivity
Authors: Annett James F
Published: November 2023

This chapter describes some of the most fundamental experimental facts about superconductors, together with the simplest theoretical model: the London equation. We shall see how this equation leads directly to the expulsion of magnetic FB01elds from superconductors, the Meissner–Ochsenfeld effect, which is usually considered to be the fundamental property which deFB01nes superconductivity.

The chapter starts with a brief review of the Drude theory of conduction in normal metals. We shall also show how it is possible to use the Drude theory to make the London equation plausible. We shall also explore some of the consequences of the London equation, in particular the existence of vortices in superconductors and the differences between type I and II superconductors.
The Dirac operator
Authors: Hitghin Nigel
Published: November 2023

Take a trip to London and go to Westminster Abbey. Enter by the main door, follow your way round past the clusters of tourists, the tombs of kings and queens and long-forgotten bastions of society, out into the cloisters, back into the nave, cross over past the unknown soldier to reach the backwater by the screen which is where science holds sway.
Introduction
Authors: Tabor D
Published: November 2023

In his introductory essay on the hardness of metals O’Neill (1934) has wisely observed that hardness, ‘like the storminess of the seas, is easily appreciated but not readily measured’. In general hardness implies the resistance to deformation. If we accept the practical conclusion that a hard body is one that is unyielding to the touch, it is at once evident that steel is harder than rubber. If, however, we think of hardness as the ability of a body to resist permanent deformation, a substance such as rubber would appear to be harder than most metals. This is because the range over which rubber can deform elastically is very much larger than that of meta.ls. Indeed with rubber-like materials the elastic properties play a very important part in the assessment of hardness. With metals, however, the position is different, for although the elastic moduli are large, the range over which metals deform elastically is relatively small. Consequently, when metals are deformed or indented (as when we attempt to estimate their hardness) the deformation is predominantly outside the elastic range and often involves considerable plastic or permanent deformation. For this reason, as we shall see, the hardness of metals is bound up primarily with their plastic properties and only to a secondary extent with their elastic properties. In some cases, however, particularly in dynamic hardness measurements, the elastic properties may be as important as the plastic properties of the metals.
Deformation of Metals by Spherical Indenters Metals which Work-Harden
Authors: Tabor D
Published: November 2023

So far we have discussed the deformation of a metal by a spherical indenter when the metal has a yield stress Y that is essentially unaffected by the deformation produced by the indentation process itself. In practice this behaviour is characteristic of metals which are very • worked, so that its practical application is somewhat limited. In this chapter we shall consider the extension of this analysis to metals which are annealed or only partially worked, so that they experience work-hardening during the indentation process. It may be said at the outset that a theoretical treatment of this problem has not been solved even for the case of two-dimensional deformation. We must therefore approach the problem in an empirical way.
Area of Contact Between Solids
Authors: Tabor D
Published: November 2023

We may now discuss a more general problem which frequently occurs in one form or another in engineering practice. When two metal surfaces are placed in contact, what is the real area of contact between them ? However carefully the surfaces are prepared they will be covered with hills and valleys which are large compared with atomic dimensions, so that the surfaces when first placed in contact will be supported on the tips of their asperities. The question is thus modified to a discussion of the way in which the surface asperities are deformed when the surfaces are placed in contact. We may first assume that one surface is harder than the other and that the asperities on the harder surface are hemispherical at their tips. Suppose such an asperity presses on to a flat asperity of the softer surface. We may at once use the results discussed in Chapter IV. At first the deformation is elastic, but for asperities of the order of l 0-4 cm. radius the minutest loads will produce plastic deformation. Indeed full plasticity may occur even for the hardest steels at a load of the order of a few milligrams. Consequently for loads used in practice each asperity produces plastic flow and behaves like a minute Brinell indenter.
Effect of Frictional Heating on Surface Flow
Authors: Bowden F P , Tabor D
Published: November 2023

In this chapter we shall discuss the effect of surface temperatures produced by frictional heating on surface melting and surface flow. The first part deals with the process of polishing; the second with the sliding on ice and snow. The usual method of polishing surfaces is to rub them together with a fine powder between them. By this process a rough surface having visible irregularities is changed into one where the irregularities are invisible. If the surface gives specular reflection the height of these irregularities will be less than half a wave-length of visible light.
Friction of Clean Surfaces: Effect of Contaminant Films
Authors: Bowden F P , Tabor D
Published: November 2023

In the previous chapters we have dealt with friction experiments carried out on metal surfaces which have been cleaned in the atmosphere. It is clear, however, that when solids arc cleaned in air their surfaces are still covered by a thin film of oxide, water vapour, and other adsorbed impurities. The contaminant film is usually at least several molecular layers in thickness, and any complete theory of friction must take this film into consideration. As we shall see, even the thinnest surface films may have a profound effect on the friction.
Boundary Friction of Lubricated Metals
Authors: Bowden F P , Tabor D
Published: November 2023

In hydrodynamic or fluid lubrication the surfaces in relative motion are separated by a lubricant layer of appreciable thickness and under ‘ideal’ conditions there is no wear of the solid surface. The resistance to motion is due entirely to the viscosity of the interposed layer. In practice, how ever, it is often impossible to obtain fluid lubrication, particularly if the sliding speeds are low or the loads are high. In such cases the thick lubricant layer breaks down and the surfaces are separated by lubricant films of only molecular dimensions. Under these conditions, which Hardy (1936) referred to as boundary conditions, the friction is influenced by the nature of the underlying surface as well as by the chemical constitution of the lubricant. The bulk viscosity plays little or no part in the frictional behaviour.
Current methods of studying bird migration
Authors: Berthold Peter
Published: November 2023

Before the first experiments were carried out on migratory birds (Chapter 3), bird migration research was restricted to accidental or systematic observations, occasionally supplemented by hunting. Today, modern migration research employs a wide variety of methods. Some are simple, well-proven, and still indispensable.
Physiological bases and control of bird migration
Authors: Berthold Peter
Published: November 2023

This chapter deals with the physiological processes and behavioural changes which occur or are apparent in migrants before they actually embark on any large-scale movements. Migratory disposition is a complex behavioural and physiological condition which characterizes a migrant that is ready for departure.
Hut no. 2
Authors: Gregory Jane
Published: November 2023

Many of the university ‘s scientific staff were gone, already set to work on war projects in secret defence research stations. The nuclear physicists had formed their own private group within the Cavendish Laboratory, concentrating on nuclear flssion and the possibility of an atomic bomb. Former staff had come out of retirement to continue the teaching, and the place livened up when the University of London evacuated its students away from the bombing to the rather safer Cambridge. What Hoyle recalled as a ‘blizzard of regulations ‘ was imposed upon the nation, Cambridge included: all men of working age were to be registered, children in cities sent to the country, all windows blacked out after nightfall, and food rationed.
New world
Authors: Gregory Jane
Published: November 2023

Hoyle’s academic output for the early 1950s was relatively slight. He published only 13 new papers in the years 1950 to 1953, half the number for the years 1946 to 1949.1 Nor were colleagues citing his papers in their own work as frequently as before. He was actively producing papers, but Hoyle felt he was suffering from ‘a sort of revenge’ by scientific colleagues because of his public profile and the success of the radio programmes.
New Genesis
Authors: Gregory Jane
Published: November 2023

After their collaboration with Fowler in Cambridge, Geoffrey and Margaret Burbidge had joined him in California, where they continued to work on the origin of the elements. With Hoyle there too, they pondered the nuclear reactions that might produce elements in stars. They were encouraged by a recent review article, ‘The Abundance of the Elements ‘ by the nuclear physicists Hans Seuss and Harold Urey, whom the Bur bidges knew from their time in Chicago, which much clarified the abundance data, and indicated that an important process in the formation of new elements must be that nuclei catch and hold on to neutrons.
Eclipsed
Authors: Gregory Jane
Published: November 2023

Unanimity was reached on only one point: Is [this poll] helpful to scientific progress? 0.0 100.0 0.0Had Martin Ryle been polled, he would no doubt have been among the60.5 per cent who had high hopes of radio-astronomy. Although a Cambridge colleague of the steady-state authors, he had already clashed with them, publicly, many times. But the long history of animosity would be trumped by events in 1961.
His institute
Authors: Gregory Jane
Published: November 2023

On 15 October 1964, Harold Wilson’s Labour Party ousted Sir Alec Douglas-Home’s Conservatives, after 13 years in Opposition. The Labour victory was seen by many as a triumph for the working man, for the North over the South, and for the grammar-school meritocracy over the aristocrats. The pronouncements of the new Prime Minister would be delivered from Downing Street in a Yorkshire accent. Hogg and Boyle both held their seats in Parliament, but with the change of government they lost their ministerial responsibilities for Education and Science. The civil servants, however, spent election day preoccupied with Hoyle. Cockcroft saw
The end of the beginning
Authors: Gregory Jane
Published: November 2023

Now that the struggle is all over I am recovering rapidly. Already there is a big change here in Cambridge. At the last moment there was a sort of cooperative effect in which the project received nearly unanimous support. I trust plans stand – that you, Geoffi and Margaret will be coming next summer the builders have promised to finish next summer.
Location, structure and function of incubation sites
Authors: Hansell M H , Deeming D C
Published: November 2023

It is only in a minority of species of birds that the role of caring for eggs is the sole responsibility of the parents, instead most birds build some kind of nest to which they devolve some of the role of parental care. Indeed the interaction between the bird-nest unit is central to successful incubation (Chapter 1). This requires an investment of time and energy into the construction of a nest, with the benefit to parents of removing later costs, giving them greater flexibility in allocating time and energy to other activities.
Intermittent incubation: predictions and tests for time and heat allocations
Authors: Hainsworth F R , Voss M A
Published: November 2023

Parental behaviour to maintain a stable thermal environment is important for normal development of avian embryos (White and Kinney 1974; Hainsworthet al. 1998). Thus, single-sex intermittent incubation is a particularly interesting parental behaviour because when the parent leaves the nest there are cycles of egg cooling and heating over often short periods of time. Temperature variation should influence rate of embryo development because of lower average egg temperatures (White and Kinney 1974; Hainsworth 1995; Hainsworthet al. 1998). Since continuous incubation should be most beneficial for developing embryos, intermittent incubation has been thought to represent a compromise in development forced by requirements for parental survival (White and Kinney 1974; Hainsworthet al. 1998). It would be interesting to investigate if this compromise can be measured quantitatively so as to test the validity of this belief.
Ensembles
Authors: Wark J S , Glazer A M
Published: November 2023

We have to confess at this time to having performed a ‘sleight of hand’ earlier on when deriving the formulae for the Bose-Einstein and Fermidirac distributions. You will recall that the final formulae included a term, µ, the so-called chemical potential.
Peatswamp Forests
Authors: Whitten Tony , Damanik Sengli J , Anwar Janzanul , Hisyam Nazaruddin
Published: November 2023

Peat is a soil type with a very high organic content. It is defined, for the purposes of this chapter, as a soil at least 50 cm deep which, when dried and burned, will lose more than 65% of its mass (Driessen 1977), and is therefore more than 65% organic matter. Certain international agricultural-oriented criteria now define peat as a soil with more than 30% organic matter (Driessen and Soepraptohardjo 1974), but peatswamp forests do not develop on such soils (Anderson 1964). It is estimated that the natural area of peat soils in Sumatra was once 7.3-9.7 million ha (Andriesse 1974), or about one-quarter of all tropical peat lands (Driessen 1977).
Lowland Forests
Authors: Whitten Tony , Damanik Sengli J , Anwar Janzanul , Hisyam Nazaruddin
Published: November 2023

The lowland forests of Sumatra are among the most diverse, awe-inspiring, complex and exciting ecosystems on Earth. They are probably the best-studied forested natural ecosystem on the island, but for information on how these forests actually function it is frequently necessary to turn elsewhere in the Sunda Region. In many respects, the Sunda Region lags behind tropical America in unravelling and understanding ecological interactions. For this reason, occasional examples are taken from lowland forests in countries such as Costa Rica, when illustrations of particular aspects of ecology are required.
Mountains
Authors: Whitten Tony , Damanik Sengli J , Anwar Janzanul , Hisyam Nazaruddin
Published: November 2023

Sumatra has a large number of mountains, some, such as most of those in the Barisan Range, formed by uplift of sedimentary deposits and others, such as Mt. Kerinci, Mt. Sinabung, Mt. Merapi and Mt. Singgalang, formed by volcanic action. The physical environment changes up a mountain, thus providing a gradual change of conditions against which the fauna and flora can be examined. These differences between the montane ecosystems and the luxuriant, hot and humid lowland forest ecosystems are stimulating subjects for study.
Caves
Authors: Whitten Tony , Damanik Sengli J , Anwar Janzanul , Hisyam Nazaruddin
Published: November 2023

Very few studies have ever been conducted in Sumatran caves. Musper (1934) explored a number of caves in the hills around Gumai (near Lahat), and Bronson and Asmar (1976) describe a little of the biology of Tiangko Panjang cave in Sarko, Jambi (p. 53). Some brief studies of a few caves in northern Sumatra have been conducted by teams from CRES but the most detailed collecting work was undertaken by van der Meer Mohr (1936), also in North Sumatra. He describes the fauna of two caves south of Medan (also visited by a CRES team) and one near Balige, south of Lake Toba.
Agricultural Ecosystems
Authors: Whitten Tony , Damanik Sengli J , Anwar Janzanul , Hisyam Nazaruddin
Published: November 2023

This chapter does not attempt an exhaustive review of all the different agricultural ecosystems found on Sumatra, nor an analysis of ecological constraints to tropical agriculture (for which see Janzen 1983d), Nor does this chapter discuss the fascinating home garden ecosystems which cover 20% of the available arable land in some areas of Indonesia, particularly Central Java (Penny and Ginting 1980; Sastrapradja 1979; Widagda 1981). Elsewhere, where Javanese have been settled for 20 years or so, home gardens can also be found but they do not yet cover a significant area of the arable land of Sumatra.
Intracortical Mechanisms Underlying Orientation and Direction Selectivity Studied with the GABA-Inactivation Technique
Authors: Crook John M , Kisvárday Zoltan F , Eysel1 Ulf T
Published: November 2023

It is 40 years since Hubel and Wiesel (1962) showed that cells in primary visual cortex (area 17) respond selectively to contours of a certain orientation and that most of these cells also show a preference for the direction of motion of optimally oriented contours. However, the mechanisms underlying both orientation and direction selectivity are still the subject of intense debate. Hubel and Wiesel (1962) proposed that orientation and direction selectivity in cat area 17 are established by the spatial organization of the excitatory input from the lateral geniculate nucleus (LGN) to simple cells in layer IV (the main geniculocortical recipient zone). These cells are characterized by the presence of elongated ONand OFF-subregions in their receptive fields, which are arranged side-by-side with their long axes parallel to the axis of preferred orientation. Each of these subregions was thought to arise as a result of excitatory convergence from either ON or OFF-center geniculate cells whose receptive fields are aligned in a row in visual space, with the axis of alignment determining the orientation preference of the postsynaptic cell.
In Search of the Role of Extrageniculate Corticothalamic Loops in Visual Processing using Reversible Deactivation Techniques
Authors: Casanova Christian
Published: November 2023

The importance of visual extrageniculate nuclei, such as the pulvinar complex, became apparent when Diamond and colleagues (Diamond and Hall 1969; Killackey and Diamond 1971), Schneider (1967, 1969) and Trevarthen (1968) demonstrated the involvement of a second retinofugal visual system, the retino-collicular pathway, in orienting behavior (the Where pathway as opposed to the What or retino-geniculocortical pathway). Indeed, in order to reach the visual cortex, signals from the superior colliculus and the pretectum must be relayed by thalamic nuclei, and in particular, the pulvinar complex. Since this pioneering work, there have been a number of investigations that revealed the complex organization and connectivity of pulvinar nuclei in cats and monkeys (Vidnyánszky et al. 1996; Rockland 1996, 1998; Rockland et al. 1999).
Cortical Modulation of Auditory Processing in the Thalamus
Authors: Villa Alessandro E P
Published: November 2023

The thalamus is the main source of input to the sensory areas of the cerebral cortex of mammals. Reciprocal connections exist between these structures and sensory information is processed in a complex way in the thalamus, so it cannot be regarded as a mere relay station conveying peripheral inputs to the cortex (Jones 1985; Steriade and Llinas 1988; Murray and Guillery 1996). Furthermore, there is now convincing evidence that the different states of consciousness (a fortiori wakefulness vs. sleep) are correlated with a modified output of the thalamus to the cortex, and that alterations of information processing by thalamic circuits may play a role in certain forms of epilepsy (Steriade et al. 1990, 1993). Intracellular recordings and models of the electrophysiologic properties of thalamocortical relay cells have demonstrated that these cells may discharge either in a “tonic” or a “bursting” mode (Jahnsen and Llinas 1984a,b; McCormick and Huguenard 1992).
Examining the Basis of Neural Plasticity Using Chronic Pharmacologic Applications
Authors: Galuske Ralf A W , Kim Dae-Shik , Schmidt Kerstin E
Published: November 2023

The most common method to assess neural activity in the brain is to extracellularly record the discharges of neurons during sensory stimulation. Generally, this approach permits the measurement of responses from a single neuron per electrode. This technique is the method of choice for the basic exploration of neuronal properties. However, for many sensory cortical areas it is well established that neurons with particular functional properties are not randomly distributed over the entire area, but are clustered together into small groups with similar functional properties forming ordered two-dimensional representations or maps of different stimulus features (e.g. Hubel and Wiesel 1962; Hubel et al. 1978; Bonhoeffer and Grinvald 1991).