bluuebunny/crossref_metadata_2025 huggingface dataset:
High-temperature superconductivity and an apparent breakdown of causality
Authors: Weger M
Published: November 2023

Erwin Hahn’s discovery of spin echoes surprised the scientific community because it seemed to be a violation of the second law of thermodynamics. The formation of the echo seemed to indicate a violation of time reversal. Violating causality is one of the strictest taboos of theoretical physics, and the formation of spin echoes seemed to break this taboo. As a graduate student of Hahn I was particularly impressed by the demonstration of the ink strip in glycerol between rotating plastic cylinders, which can be made to disappear and reappear in apparent contradiction of the most basic principles of physics. At present, we encounter a mystery in our understanding of (or, rather the failure to understand) high temperature superconductivity. The experiments are simple, clear, definitive, and very detailed; but the theory is apparently missing. I shall try here to make the point that the cause of this difficulty is over-sensitivity to the apparent breakdown of causality.
The two-pulse spin echo revisited
Authors: Walstedt R E
Published: November 2023

A formulation of the two-pulse spin echo problem appropriate to inhomogeneously broadened NMR lines in solids is presented and discussed. The classical formulation is discussed in the text, with the (equivalent) quantum case outlined in an appendix. The in-phase and quadrature components of the echo signal are given by integrals over the lineshape functiong(w);these integrals can be evaluated numerically in a straightforward fashion. An exact expression is given for the area under the echo waveform, relating it to the areas under the two r.f. pulse field profiles H1(t). The echo area is directly proportional to the lineshape amplitude at the applied r.f. frequencyg(wrr),Thus, one can in principle resolve structure of arbitrary complexity by recording the area under the echo. Numerical calculations are presented to show the dependence of the echo waveforms on pulse shape and length, and on the r.f. frequency relative to the peaks of symmetric and asymmetric NMR lines. The exact phase symmetries of spin echoes are shown to be useful in eliminating unwanted electrical transients from experimental echo signals. A practical example is given.
Coherent Raman beats in electron paramagnetic resonance spectroscopy
Authors: Bowman M K , Massoth R J , Yannoni C S
Published: November 2023

Coherent Raman beats are discussed in the context of electron paramagnetic resonance spectroscopy in the solid state. A general formula is found in the case of many nuclei coupled to a single effective spin S = paramagnetic centre. The results correspond exactly to the idealized three-level model described earlier by Brewer and Hahn in optical spectroscopy in the gas phase. Methods for generating coherent Raman beats are discussed. A single preparation pulse approximating the Hartmann-Hahn match for cross-polarization between the electron spin in its rotating frame and the nuclear spins in their effective field can generate coherent Raman beats. The electron spin echo envelope modulation (ESEEM) is found to be intimately related to coherent Raman beats. Experimental observation of coherent Raman beats is described for free radicals in a single crystal of irradiated malonic acid at room temperature. The coherent Raman beats occur at one of the nuclear ENDOR frequencies.
Optical excitation and detection of spin precession
Authors: Mehring M , Wäckerle G , Appelt S
Published: November 2023

Soon after the discovery of the principal phenomenon of nuclear magnetic resonance (NMR) by Purcellet al.[1] and Blochet al.[2] , it was Hahn [ 3] who realized that spin precession can be observed directly in the rotating frame as a transient phenomenon called free induction decay (FID). In linear response theory, both phenomena, the continuous wave (c.w.) observation and the free precession are related to each other by Fourier transformation. Within the same year, however, Hahn realized that there is more to the motion of spins than just a linear response to radiofrequency field excitation and discovered the spin echo phenomenon [ 4] which led to the foundation of modern NMR spectroscopy and nonlinear optical spectroscopy. In this contribution we want to present a special view on how these early principles of Hahn influenced the development of Optical Excitation and Detection of Spin Precession. For this purpose we consider a very simple physical system, namely an atomic vapour. In optical pumping spectroscopy it is well known that the transmitted light intensity is modulated by irradiating the system with resonant radiofrequency (r.f.) fields [5-8]. By monitoring the transmission of light as a function of the r.f., sublevel splittings of the optically connected states can thus be measured, which are usually not resolved in the Dopplerbroadened optical spectrum.
The manifold Model for space-time
Authors: Joshi Pankaj S
Published: November 2023

By the space-time manifold we mean a four-dimensional differentiable manifold M together with an indefinite Lorentzian metric tensor g which has signature (-, +,+,+). The space-time (M, g) will be assumed to be space and time orientable and will obey several necessary topological regularity conditions such as the Hausdorffness, connectedness and so on, as we shall point out here. Such conditions provide physical reasonability to the space-time model being considered. In this chapter, we specify this basic model of space-time universe which is fundamental to the general theory of relativity and which underlies our considerations here on the global aspects in gravitation and cosmology.
Solutions to the Einstein equations
Authors: Joshi Pankaj S
Published: November 2023

The purpose of this chapter is to discuss several useful space-times which are exact solutions of Einstein equations, and to review some of their properties that are referred to in later chapters. The Einstein equations form a highly non-linear system of differential equations and due to their complexity, a completely general solution is not known. Thus, the known exact solutions usually assume a rather high degree of symmetry such as the spherical or axial symmetry, and the existence of necessary Killing vector fields on the space-time, and to that extent represent an idealized situation. However, such space-time examples provide a good idea of what is possible within the framework of the general theory of relativity outlined in the previous chapter.
Singularities in general relativity
Authors: Joshi Pankaj S
Published: November 2023

In this chapter, we consider the question of nature and existence of spacetime singularities in the general theory of relativity. After Einstein proposed the general theory describing the gravitational force in terms of space-time curvature and proposed the field equations relating the geometry and matter content of the space-time manifold, the earliest solutions found for the field equations were the Schwarzschild metric representing the gravitational field around an isolated body such as a spherically symmetric star, and the Friedmann cosmological models. Each of these solutions contained a space-time singularity where the curvatures and densities were infinite and the physical description would break down.
Gravitational collapse and cosmic censorship
Authors: Joshi Pankaj S
Published: November 2023

In this chapter, we investigate the issue of the final fate of a gravitationally collapsing massive star and the associated cosmic censorship problem. When the star is heavier than a few solar masses, it could undergo an endless gravitational collapse without achieving any equilibrium state. This happens when the star has exhausted its internal nuclear fuel which provides the outwards pressure against the inwards pulling gravitational forces. The theory of singularities discussed in Chapter 5 then implies that for a wide range of reasonable initial data, a space-time singularity must develop. The conjecture that such a singularity of gravitational collapse from a regular initial surface must always be hidden behind the event horizon of gravity is called the cosmic censorship hypothesis (Penrose, 1969). Thus, cosmic censorship implies that the final outcome of gravitational collapse of a massive star must necessarily be a black hole which covers the resulting space-time singularity. Then, causal messages from the singularity cannot reach the external observer at infinity and the predictability in space-time is fully preserved. This hypothesis lies at the foundation of currently well developed and applied theory of black hole physics.
A dynamical systems approach to time series analysis
Authors: Mullin Tom
Published: November 2023

The aim of this chapter is to show how the information extracted from a physical experiment or numerical computation may be analysed using modern signal processing techniques and indicate how the results can be related to ideas from finite-dimensional dynamical systems. The ultimate objective is to see whether a direct connection can be made between the information contained in the time series obtained from a continuous infinite-degree-of-freedom system and the well-developed field of chaos in ordinary differential equations and maps. Before we proceed with the description of the modern nonlinear techniques, we will first of all briefly discuss the traditional linear methods of signal processing. Next we will introduce the concepts of phase portrait reconstruction using the straight-forward ‘method of delays’. The principles are extended by a discussion of the singular value decomposition technique which provides a systematic way of selecting a coordinate system in which the attractor can be constructed and which also deals with the universal problem of noise in experimental observations. A brief discussion of the construction of Poincare maps is then presented as a useful technique for reducing the dimension of the reconstructed attractor. Finally, we discuss the merits and practical limitations of methods of obtaining quantitative estimates from these nonlinear signal processing techniques.
Cooling The Stored Ions
Authors: Ghosh Pradip K
Published: November 2023

The ions trapped, whether in the Paul trap or in the Penning trap, usually have energies of the order of 1 eV, that is, a temperature of about 10 000 K. High temperature means high kinetic energy, and this is un favourable to most trap-based experiments for the following reasons. First, with high kinetic energy, amplitudes of ion oscillations are high and consequently the chances of ion losses are high; this results in loss of sensitivity. Second, high kinetic energy enhances both the first-order and the second-order Doppler effects; so, unless the ions are cooled, all spectroscopic experiments are adversely affected in a major way. While isolation of the ions in the trapped condition does not permit ion energy to be easily dissipated to the surroundings, for the same reason, the trapped ions can be effectively cooled and, once cooled, they can be retained cold in the trap. In recent years, most of the trap-based experiments have used ion cooling of one kind or the other. In this chapter we present an overview of various cooling methods and their applications.
Physical foundations of the Casimir effect
Authors: Mostepanenko V M , Trunov N N , Znajek R L
Published: November 2023

The physical basis of the second quantization procedure is the representation of the field as a system of oscillators. It is therefore desirable to consider briefly those oscillator properties that will be important to us, starting with the simplest case of non-relativistic quantum mechanics.
Introduction
Authors: Kimsey Lynn S , Bohart Richard M
Published: November 2023

Gold wasps or cuckoo wasps are common names often applied to the family Chrysididae. Their frequently metallic coloration justifies the former, and cleptoparasitic habits refer to the latter. This brilliant aspect is best observed on a sunny day as the female wasp is searching a nesting site of a favoured wasp host. The sunlight reflects from the parasite and seems to accentuate the metallic colours—blue, green, purple, red, copper, brass, and gold—in various combinations. Most chrysidids are small and, although not all are brilliant, the tiny ones often make up for in colour what they lack in size. The sight of a Hedychridium moving erratically over the sand like a drop of pure gold never fails to astonish the collector. In the Western Hemisphere most chrysidids are metallic blue, green, and purple, in various combinations. In the old world, especially in the southern USSR and Africa, these wasps are often more colourful. A single specimen may be green, blue, purple, copper, gold, and red; all somewhat iridescent. These are interference colours. The true pigment shades of red, brown, and white are not so common. In addition to the often bright integument are the myriads of tiny impressions or punctures which are nearly always present. These modify and often enhance the coloration.
Introductory remarks
Authors: Jones D M
Published: November 2023

Barber Conable, the President of the World Bank, in a speech on Development and the Environment given in Tokyo two months ago, highlighted the significance of global human population growth in environmental change. It took about 130 years for the world’s population to grow from 1 to 2 billion. It will take just 10 years, to the end of the century, to grow from its current level of 5 billion to 6 billion. Ninety per cent of that growth will be in the developing world and in some countries, many of which (such as Kenya and Brazil) are of particular interest to us in this room, the population will double in the next 20-30 years. The most optimistic scenario predicts that world population will stabilize at between 8 and 9 billion sometime in the third decade of the next century, provided that the fundamental and closely linked problems of under-development, poverty, misuse of resources (especially of energy) and environmental ignorance are actively tackled.
Life after extinction
Authors: Seal U S
Published: November 2023

There has emerged on the rapidly changing face of our planet a pattern of an increasing number of animal and plant species reduced in distribution, populations and numbers. Species relatively numerous in total numbers are being fragmented into small isolates with no exchange between them. Small populations face genetic, demographic and environmental risks as a result of their small size and isolation (Ralls, Brugger & Ballou 1979; Ralls & Ballou 1983; Soule 1987). In the extreme case a species is reduced to one population, oscillating and shrinking in numbers, losing genetic diversity and subject to abrupt reductions or extinction through the random whims of natural events or man (Franklin 1980; Gilpin & Soule 1986; Lacy 1987; Goodman 1987).
Analysis of polygamous systems using DNA fingerprinting
Authors: Amos Bill
Published: November 2023

DNA fingerprinting is a method for resolving genetic differences between closely related individuals. In many species the levels of variabilty revealed are sufficient to allow positive paternity analysis. Unfortunately considerable logistic problems are encountered wherever sample sizes are large and putative fathers have not been identified by prior behavioural observations. Clearly the worst cases involve species with highly polygamous mating systems.
Induced genetic variations
Authors: Jablonka Eva , Lamb Marion J
Published: November 2023

In the previous chapter we considered how new genetic information present in somatic cells could cross ‘Weismann’s barrier’ and become part of the germ line. In each of the cases we looked at, the new information was assumed to have arisen through random mutation. Cells with new mutations were subject to Darwinian selection before they, or their DNA, entered the germ line. Although the outcome was Lamarckian, the mechanism was not. The inheritance of acquired characters requires not only that information from the soma is transferred to the germ cells, but also that the environment is instrumental in producing the new variations. Mutations should arise as specific responses to environmental change. They should be directed, not random.
The inheritance of directed epigenetic variations
Authors: Jablonka Eva , Lamb Marion J
Published: November 2023

With classical imprinting, parents transmit to their offspring chromatin marks carrying the stamp of the parent’s sex. The mark is usually transient, and is reversed in the next generation if it passes through the germ line of the opposite sex. Imprinting is therefore a rather special case of the transmission of epigenetic information between generations. A few cases in which a mark is transmitted in a sex-independent fashion and in a more permanent manner have been found with imprinted transgenes, but transgenes are in many ways atypical an’d differ from normal genes. To show that epigenetic inheritance can occur between generations and can have direct evolutionary significance, similar sex-independent and more permanent transmission must be found with normal genes.
The role of epigenetic inheritance systems in adaptive evolution
Authors: Jablonka Eva , Lamb Marion J
Published: November 2023

Our aim in this chapter and the next is to show how, by broadening Darwinian theory to give a role to the biochemically well-recognized EISs discussed in Chapter 4, it is possible to give an explanation of some aspects of evolutionary history that is more satisfying than that based on natural selection of random DNA variations. Both the direct and indirect effects of epigenetic inheritance have been important in evolution. We first discuss the way in which high mutation and epimutation rates may have been moulded by natural selection, and how the frequency of epialleles changes in populations. We then argue that the evolution of complex multicellular organisms was made possible by EISs that already existed in unicellular organisms, and that EISs have shaped some of the developmental strategies seen in higher animals and plants. We also discuss the role of epigenetic variations in macroevolutionary changes.
The evolution and diversity of bats
Authors: Altringham John D
Published: November 2023

Bats are currently placed in a single order, the Chiroptera. They are divided into two sub orders, the Mega- and Microchiroptera, commonly referred to as the megabats and micro bats. The megabats are the Old World fruit bats: large (for bats, 20-1500 g), exclusively plant-eating (i.e. they eat fruit, flowers, nectar, and pollen), and confined to Africa, tropical Asia, and Inda-Australasia. There are about 175 living species, all belonging to one family, the Pteropodidae. Microbats on the other hand are found on every continent except Antarctica, and on many isolated islands. They are, as their name implies, generally smaller than megabats (1.5-150 g), and they eat all sorts of things, as we’ll discover later, although the ancestral microbat almost certainly ate insects and other arthropods. The approximately 790 species are distributed among 17 families. Figure 1.1 will fulfil our immediate needs as we look at the origins of bats, and the source of this diversity. It shows the known fossil bats in relation to a simplified evolutionary tree of extant bats.
Flight
Authors: Altringham John D
Published: November 2023

There are several excellent accounts of aerodynamics in relation to animal flight, and all will be mentioned somewhere in the chapter, but for a recent and very wide ranging book on all aspects of vertebrate flight, you should go to Norberg (1990). Pennycuick (1972) has written a short and very readable book on animal flight, and more recently (1989) a book and computer program for experimenting with flight morphology and performance. A real understanding of flight can only be gained if you are familiar with a little of the terminology and some of the concepts of aerodynamics, so that is what we will start with. The shape of an idealised aerofoil, and that of a bat’s wing, are shown in Fig. 2. la. The tapered profile and convex upper surface are responsible for the forces generated by an aerofoil which keep the bat in the air and move it forward. Because of this shape, air flowing over the top of the wing must move faster than that flowing below (Fig. 2.la). This results in an area of low pressure above the wing, and high pressure below, and therefore a net aerodynamic force (NAF) which raises the wing (Fig. 2.1b). If the bat is to go forward, then the NAF must have two components, a vertical, lift component to overcome the effect of gravity, and thrust to overcome drag. The wings and body of the bat experience drag which resists forward movement. Drag is usually minimised by having a streamlined shape, but is always significant, at around 10-20% of the lift. Since lift acts at right angles to the movement of the wings, the wings must move forwards and down wards relative to the airflow. A gliding bat (Fig. 2.1c) achieves the right angle of incidence to overcome drag by losing height. The angle of incidence (or attack) is the angle the aerofoil makes with the plane of the airflow. A flapping bat must use appropriate wing movements (kinematics) during the downstroke and the upstroke to overcome drag.
Echolocation
Authors: Altringham John D
Published: November 2023

Echolocation is a complex and highly evolved process which has given bats the ability to exploit an ecological niche closed to all but a few animal groups-the night sky. Echolocation is not unique to bats, but it has arguably reached its evolutionary peak in these mammals. What is echolocation? A simple definition is that it is the analysis by an animal of the echoes of its own emitted sound waves, by which it builds a sound-picture of its immediate environment. A number of animals use sound in this way, and many use high frequency sounds or ultrasounds, beyond the range of human hearing. These include, as well as the bats, the Cetacea (whales and dolphins: see Au, 1993) and the insectivores (shrews and tenrecs). It is not clear how sophisticated ultrasonic echolocation is in the insectivores but there is no doubt about its value in cetaceans. Ultrasonic sounds are also emitted by some rodents and a number of marsupials, but we do not know if they are used for echolocation, or just for communication (Sales and Pye, 1974).
Behavioural ecology
Authors: Altringham John D
Published: November 2023

Bats spend most of their lives in their roosts. Roosting habits influence local and global distribution, densities, foraging and mating strategy, social structure and seasonal movements, and even the morphology and physiology of bats. An understanding of their roosting ecology is therefore fundamental to an understanding of bats. The most wide ranging and thorough review is that by Kunz (1982). I have already talked a little about roosting ecology when we covered hibernation and reproduction. In this chapter I will take a broader view, and look at the great diversity of roosting adaptations and show how they relate to other aspects of bat biology. By choosing a suitable roost, bats can gain many advantages. Here are the most important potential benefits: The processes involved in roost selection are complex, with many mutually dependent interactions. The availability of suitable roosts, for example, will influence foraging behaviour, but roosting behaviour itself may be influenced by the abundance and dispersal of food, and both have an important role in determining the social structure of intra and interspecific bat communities.
Evolution, systematics and biogeography
Authors: Hopkin Stephen p.
Published: November 2023

There is currently a vigorous debate on the phylogeny of arthropods. Many old ideas are being overturned following molecular analysis of relationships between extant arthropod groups and discovery of new fossils. In recent years, there has been a welcome trend towards taking a much broader cladistic view of evolution, rather than forcing different arthropod groups into strict Linnaean categories (Queiroz and Gauthier 1994). In this chapter, the origins of Collembola and their relationship to other arthropods are discussed (Section 3.2). The systematics of Collembola themselves is examined (Section 3.3) and the main characteristics of each family are outlined (Section 3.4). Finally, an overview is given of the biogeography of Collembola together with a discussion of the problems involved in deter mining past and present day distributions of the different species (Section 3.5).
Taxonomic methods and the species concept in Collembola
Authors: Hopkin Stephen p.
Published: November 2023

The great majority of genera listed in Appendix A are well characterised. Most discussions about genera among taxonomists concern which species to place in them, rather than their validity. Providing the boundaries of genera are well defined, and can be shown convincingly by cladistic analysis to be monophyletic units, I see no good reason why existing genera should not be split into two or more genera, or why subgenera should not be raised to generic rank. Although some authors still use the category of subgenus in their publications (e.g. Fjellberg 1991b; Snider 1990a,b), it might be preferable to abandon subgenera altogether as their use frequently causes confusion.
Eucalypts natural and planted
Authors: Eldridge Ken , Davidson John , Harwood Chris , Wyk Gerrit Van
Published: November 2023

Species of the genus Eucalyptus are commonly known as ‘eucalypts’ throughout the world, although in Australia they are often called ‘gum trees’ because of the gum (kino) that exudes from the trunk of older trees (Zacharin 1978). The use of correct botanical names is important to growers of eucalypts when they order seed or seek information on appropriate practices in breeding and plantation silviculture. As the common name is often used for more than one species we avoid common names, except where there is no ambiguity. In this book we use botanical names. While most eucalypts can be identified fairly easily in the field as mature trees with the help of books such as those by Chippendale (1988), Boland et al.(1984), Broker and Kleinig (1983, 1990), Gutierrez (1977), or Goes (1985), there are some problems. It is certainly convenient to consider eucalypt species and subspecies as discrete taxa but it is important to remember that within most species, and between some pairs of species, there is a continuum of variation in many characteristics.
Eucalyptus deglupta
Authors: Eldridge Ken , Davidson John , Harwood Chris , Wyk Gerrit Van
Published: November 2023

Australia. The natural distribution (Fig. 7.2) is markedly discontinuous from Mindanao in the Philippines, through Sulawesi, Ceram and Irian Jaya in Indonesia, and parts of mainland Papua New Guinea and most of New Britain (Heather 1955; Davidson 1973b, 1978b; Turnbull 1974). Best development of the species is to be found in riverain situations at altitudes mainly below 150 m in New Britain. Full altitudinal range is from sea level to about 1800 m. Throughout its natural range the climatic region in which E. deglupta occurs is the humid tropics (Fig. 4.2, p. 41). Mean annual rainfall is typically 2500-3500 mm but some areas receive up to about 5000 mm. Seasonal distribution varies according to local monsoon patterns. Except for a rainshadow in south-eastern Papua New Guinea, rainfall is seldom less than 100-150 mm per month in the driest part of the year. In the lowlands mean monthly maximum temperature is around 30-32°C, while in the highlands the mean monthly maximum of the coolest month may be only 24°C.
Eucalyptus delegatensis
Authors: Eldridge Ken , Davidson John , Harwood Chris , Wyk Gerrit Van
Published: November 2023

Eucalyptus delegatensis and E. nitens are the only eucalypts which combine fast growth, cold tolerance, and production of high-quality sawn timber suitable for joinery and furniture. E. delegatensis is economically important in Tasmania, eastern Victoria, and southern New South Wales. In Tasmania and Victoria it has been the principal timber-producing species for many years, probably exceeded only byE. obliqua in total quantity of sawlogs and pulpwood harvested in those regions.
Eucalyptus globulus
Authors: Eldridge Ken , Davidson John , Harwood Chris , Wyk Gerrit Van
Published: November 2023

One of the earliest of the eucalypts to be both validly named and brought into cultivation, E. globulus was formally described by Labillardiere (1799) from a specimen he collected in southeastern Tasmania in 1792 (Fig. 10.1). It is the best known of four closely related species (or subspecies) of blue gum, the others being E. bicostata, E. pseudoglobulus, and E. maidenii (Fig. 10.2). The natural range of E. globulus is approximately 38°26’ S to 43°30’ S. Its principal occurrence is in eastern Tasmania in disjunct populations along the coast and up to 20 km inland in relatively dry open forest. Rainfall in some places is as low as 550 mm. The morphological affinity of trees in natural stands in south-eastern Tasmania with those in plantations in Europe (Orme 1978) suggests that the plantations originated from seed collections near the coast in that area.
Eucalyptus obliqua
Authors: Eldridge Ken , Davidson John , Harwood Chris , Wyk Gerrit Van
Published: November 2023

Eucalyptus ohliqua the type species of the genus (Fig. 1.2, p. 6), is one of the most widespread and economically important eucalypts of south-eastern Australia. The natural range extends from northern New South Wales to southern Tasmania between latitudes 29° and 43°S and westward as far as Kangaroo Island, South Australia (Fig. 13.1). It is known as messmate stringybark and is an attractive component of the landscape in much of the moister hill country in the part of the continent where most Australian people live.
Seed production
Authors: Eldridge Ken , Davidson John , Harwood Chris , Wyk Gerrit Van
Published: November 2023

The end product of any breeding program is the material to be used in propagating plants for afforestation or reforestation programs. Before the recent progress with mass vegetative propagation, all new eucalypt plantations originated from seed. Although vegetative propagation will decrease the demand for seed, we consider that seed will still play a major role in plantation establishment for many years. Somespecies are very difficult to propagate vegetatively and even for more favourable species many problems are still being experienced with rooted cuttings. This chapter deals with mass production of genetically improved eucalypt seed with specific discussion of seed production areas, seedling seed orchards, and clonal seed orchards.
Mass vegetative propagation
Authors: Eldridge Ken , Davidson John , Harwood Chris , Wyk Gerrit Van
Published: November 2023

Before 1960 the only genera of forest trees mass propagated for wood production by making rooted cuttings of superior individuals were Populus and Salix in temperate areas and Cryptomeria and Cunninghamia in subtropical areas. Since that time progress in cloning techniques and a better, though still far from complete, understanding of the maturation process and ways of reversing it, have led to other genera of forest trees such as Picea, Pinus, Sequoiadendron, and eventually Eucalyptus joining the list of trees able to be mass propagated by rooted cuttings. Vegetative propagation is a technique widely used in tree breeding to manage breeding populations more efficiently. Grafts, cuttings, or micropropagules of selected trees are brought together in a clone bank where the genotypes are conserved and pollinations are made near ground level, in safety. Clonal seed orchards are established using the same techniques. Vegetative propagation for clone banks and seed orchards is on a small scale compared with the mass propagation described in the following sections.
Aquatic weed problems and management in Africa
Authors: Mitchell D S , Pieterse A H , Murphy K J
Published: November 2023

Aquatic weed problems in freshwaters in Africa are caused by two groups of aquatic macrophytesAquatic weed problems in freshwaters in Africa are caused by two groups of aquatic macrophytes.
Introduction: The Australian Environment
Authors: Adam Paul
Published: November 2023

At the present day, rainforest in Australia is very limited in its distribution (opposite). It was once much more widespread, and the contraction to its present limits reflects environmental changes over many millions of years (Chapter 6). In order to provide the background for understanding why rainforest survives where it does, and is absent elsewhere, this chapter presents an overview of the environment of the Australian continent. More detailed recent reviews have been provided by Nix (1981), Bridgewater (1987), and in Jeans (1986).
An Overview of Australian Rainforests
Authors: Adam Paul
Published: November 2023

The aim in this chapter is to present a broad brush description of Australian rainforest, starting in the north-west and travelling clockwise around the continent. More comprehensive accounts are found in Beadle (1981), Figgis (1985), and Werren and Kershaw (1987).
Regeneration and Responses to Disturbance
Authors: Adam Paul
Published: November 2023

Rainforest is complex, both structurally and floristically. How is this complexity maintained? The answers to this question are of considerable interest in building up our understanding of the ecology of rainforest, and are of vital importance to those who wish to manage rainforest, whether for some form of harvest or for long-term preservation.
Controls on growth and productivity of bryophytes: environmental limitations under current and anticipated conditions
Authors: sveinbjornsson Bjartmar
Published: November 2023

Where they occur in abundance, bryophytes play a key role in the structure and function of ecosystems (Oechel and Lawrence 1985; Chapin et al. 1987). Their relative effect on the ecosystems in which they occur, including effects on nutrient cycling, soil temperature, soil moisture, soil decomposition, vascular plant biomass, and vascular plant productivity, may be far greater than the fraction of the total plant biomass they represent (Oechel and Lawrence 1985; Oechel and Van Cleve 1986; Chapin et al. 1987).
Lists of Genera in Which Certain Diagnostic Features Occur
Authors: Gregory M , Cutler D F , Keating Richard C , Keating Richard C
Published: November 2023

The list includes genera where a character state was expressed in one or more species. Within genera with many species, character variation can be high. Also, a character state may not be uniformly present throughout an organ or in all species.
The Selection And Detoxification Of Plant Material By Fungus-Growing Ants
Authors: Powell R J , Stradling D J
Published: November 2023

Most phytophagous insects have digestive systems which are adapted to cope with a limited range of plant chemical defences and are monophagous or oligophagous. However, the ability to fly over relatively large distances facilitates the search for specific food plants. It is advantageous for walking, centre-place foragers like ants to have less specialized diets, and among plant-feeding insects the leaf-cutting ants probably contain the only truly polyphagous species.
Effects of ants on temperate woodland trees
Authors: Whittaker J B
Published: November 2023

There is a large quantity of literature on the behaviour and activity of ants associated with temperate trees because red wood ants ( Formica rufa group) in particular, have been considered as potential biological control agents of forest pests. There are excellent reviews of this work by Wellenstein (1954), Cotti (1963), and Adlung (1966), amongst others, which need not be repeated here. Instead, I shall take this opportunity to place more emphasis than they do on deciduous woodlands where more recent work has been carried out, and to consider in more detail the impact of the ants on the herbivore community structure, the dynamics of the insects in the tree canopy, and the effects of ant activity on herbivory.
The Evidence For, And Importance Of, Ant Pollination
Authors: Peaked Rod , Handel Steven N , Beattie Andrew J
Published: November 2023

Despite the world abundance of ants. and the wide radiation of pollination vectors. very few plant species have been described as ant pollinated. Various authors have attempted to explain this lack of ant pollination but these explanations have never been supported by adequate data. However, a recent series of studies have suggested that antibiotic secretions may have contributed to the paucity of ant pollination systems and provide a new series of hypotheses which can be tested experimentally. One consequence of these studies is a call for a reappraisal of the published reports of ant pollination. In this chapter we briefly examine these reports and point to the need for critical experimental studies. It is hoped that this review will widen interest in ant pollination systems and encourage the discovery of other cases of ant pollination.
Light Environments, Stage Structure, And Dispersal Syndromes Of Costa Rican Marantaceae
Authors: Horvitz Carol C
Published: November 2023

Even though morphological traits of fruits, seeds, and infructescences are widely assumed to be adaptive to different kinds of dispersal (van der Pijl 1972; Howe and Smallwood I 982; Augspurger 1984), we still understand very little about the factors that select for one type of dispersal morphology instead of another (Janson 1983; Charles-Dominique 1986; Howe 1986; Janson et al. I986). The usual paradigm is that plants that inhabit early seres of successional environments (newly disturbed sites) are characterized by small, widely dispersed, frequently dormant seeds that are packaged in relatively low-energy fruits adapted for either wind dispersal or a wide array of animal foragers.
Problems Outstanding In Ant-Plant Interaction Research
Authors: Beattie Andrew J
Published: November 2023

The last few decades have witnessed a phenomenal growth in our understanding of ant-plant interactions. Nevertheless, many important questions remain to be answered. The five topics discussed here have been selected to show that these questions are both fundamental and diverse and that antplant research may be seminal in advancing our understanding of species interactions, their genetics, and their role in population dynamics and community organization. My remarks will be confined almost wholly to those interactions that are regarded as mutualistic but some of the major points apply equally to other types of interaction such as leaf-cutting and seed-eating.
Ecology of filial cannibalism in fish: theoretical perspectives
Authors: Sargent Robert Craig
Published: November 2023

Rohwer (1978) proposed a theory of filial cannibalism for fishes with paternal care, where filial cannibalism is defined as a parent eating its own offspring. Since that time, filial cannibalism has been widely documented, not only in fishes with paternal care, but also in species with maternal and biparental care (see Dominey and Blumer 1984; FitzGerald and Whorisky this volume, for review). Rohwer (1978) begins with two assumptions: (1) nesting male fishes are food limited and forced to fast; and, (2) a male’s own offspring may be an alternative source of food. Rohwer (1978) proposes that a filial cannibal trades off current offspring against an energetic investment in future reproductive success. From these simple assumptions, Rohwer (1978) provides a verbal model that potentially explains the diversity of filial cannibalism, and associated behaviours, in natural populations.
Reproductive output from the different mating systems
Authors: Davies N B , Quinn David
Published: November 2023

The aim of this chapter and the next one is to assess male and female reproductive success in the various mating systems. It is clear from the behavioural observations that there are conflicts of interest both during the setting up of breeding territories and during the mating period. Can we make sense of these given the assumption that individuals are expected to behave in ways that promote their own reproductive success? Can the outcomes of these conflicts help us to understand the dunnock’s variable mating system? In this chapter I shall consider the factors which influence the reproductive output of the various mating systems. In Chapter 9 I shall then use these results to calculate male and female reproductive success in the different combinations. The analysis is based largely on data collected in the four breeding seasons from 1981 to 1984 when I simply observed natural variation in reproductive success. In the following seasons there were extensive experimental manipulations, so these have been included only in cases where they have illuminated the causes of the natural variation.
Individual reproductive success in the various mating systems: conflicts of interest
Authors: Davies N B , Quinn David
Published: November 2023

In this chapter I shall use the data from Chapter 8, on reproductive output from the various mating systems, to assess individual reproductive success. The analysis is based largely on work I did with Alasdair Houston (Davies and Houston 1986), combined with the results from DNA fingerprinting to measure maternity and paternity (Chapter 7). In many ways this represents the culmination of the previous eight chapters. They have raised two puzzles; why does the dunnock have such a variable mating system and why are there such intense conflicts among individuals over mate guarding and paternity? The assumption underlying modern interpretation of animal behaviour is that individuals will adopt behaviour patterns which best promote their own reproductive success. Measuring the reproductive consequences of behaviour patterns is therefore crucial to an understanding of why individuals behave in particular ways. I shall show how measuring individual reproductive success not only helps solve the puzzle of why there are conflicts of interest in dunnock behaviour, but also provides the key to understanding why there is a variable mating system. In solving the second puzzle, therefore, we can provide an answer to the first.
Parental effort by males and females pairs and trios
Authors: Davies N B , Quinn David
Published: November 2023

We ended Chapter 9 with the pleasing conclusion that the observed conflicts of interest between individuals make good adaptive sense, given their reproductive payoffs from the various mating systems. It might be thought that we could now end the book with the claim that the dunnock puzzle has been solved. However, all we have really done is to push the problem back a step. Why have the reproductive payoffs ended up at the particular values we observe? Why, for example, does the beta male not help more with chick feeding so that it pays the alpha male to cooperate? If this happened, then there would be no male-female conflict over the occurrence of cooperative polyandry. Likewise, why does a polygynous male not help his females more so that they do not suffer costs from reduced chick care? If this happened, then there would be no male-female conflict over the occurrence of polygyny.
Paternity and parental effort: how good are male chick feeding rules?
Authors: Davies N B , Quinn David
Published: November 2023

One of the most important findings of this study is that male and female behaviour makes good adaptive sense in terms of maximising individual reproductive success (Chapter 9). The first reaction of a colleague was: ‘Well, those dunnocks must be very clever to work out all the reproductive payoffs in Table 9.4!’ The standard reply is that the animals themselves need not be aware of the consequences of their actions. The dunnock’s cryptic plumage has presumably evolved without individuals being aware of exactly how the crypsis works. In the same way, behavioural strategies can evolve without individuals working out all the costs and benefits. It is natural selection which judges the success of alternative strategies, favouring those which best promote an individual’s reproductive success, the means by which genes programming those strategies proliferate in the population. Individuals may play their strategies unconsciously, as programmed by their genetic and physiological make-up; this will influence, for example, plumage colour, the tendency to be aggressive to rivals, work rate in chick feeding, and so on.
Beyond dunnocks: sexual conflict, parental care and mating systems
Authors: Davies N B , Quinn David
Published: November 2023

The three main conclusions of the book are as follows. First, the variable mating system of the dunnock reflects the various outcomes of conflicts of interest among males and females, with each individual selected to maximise its own reproductive success, often at the expense of others. Second, conflicts of interest underlie even seemingly cooperative ventures, with no visible squabbles, such as the provisioning of a brood of young by a male-female pair or a two male female trio. Third, individuals use simple rules to guide their behaviour, rules which on average promote their own reproductive success but which are far from perfect, sometimes leading to maladaptive outcomes such as the provisioning of a brood where a male has no paternity or even the provisioning of young of the wrong species. In this final chapter I shall consider the general interest of these three themes, particularly for studies of other bird species.
Introduction
Authors: Itö Yosiaki
Published: November 2023

This book is a development of the ideas that I first presented in Karibati no syakai-sinka (Social evolution of wasps, published by Tokai University Press, Tokyo, in 1986).The social insects represent the peak of social integration among invertebrate animals. Thus honey-bee queens cannot live alone, but must always be helped by workers. The workers do not mate, though they can lay male-destined (haploid) eggs when their queen is lost. This is however, exceptional; the workers usually devote their lives to feeding their queen’s young and defending their nest, sometimes sacrificing their own lives in the process. Such social systems, characterized by the existence of complete or incomplete division of reproductive labour (the coexistence of two or more ‘castes’) and by co-operation among colony members, are defined as ‘eusocial’ (Wilson 1975).
Multi-queen societies: swarm-founding wasps in the tropics
Authors: Itö Yosiaki
Published: November 2023

Honey-bee colonies reproduce by ‘swarming’ (colony fission). When a colony produces new queens at a certain stage of colony growth, the old queen disperses from her nest together with a group of workers and this queen-worker group builds a new nest. Stingless bees also reproduce by swarming, but in this subfamily the new queens and some of the workers disperse from their natal nests (Sakagami 1984 ).
Kin-selection and multi-queen social systems: conclusion
Authors: Itö Yosiaki
Published: November 2023

The existence of completely, or almost completely, sterile workers, as seen in honey-bees, hornets, ants, termites, and soldier-producing aphids, however, seems to be inexplicable without kin-selection. Workers which cannot leave any progeny (including male eggs), such as the soldiers of termites and aphids, are unable to gain any fitness from mutualism with unrelated colony members. Even for workers which can reproduce after the death of queens, the probability of succeeding the queen is almost zero if the colony size is more than 1000. A genetic trait which leads mothers to sterilize their first progeny by nutritional, pheromonal, or behavioural castration, and then to produce reproductives, can be selected for if the mothers can produce more reproductive progeny than mothers without this trait (parental manipulation of Alexander 1974). At least for eusocial wasps, however, the overlapping of the emergence and of the morphological structure of workers and reproductives, and the possibility of a revolt by progeny in tropical areas makes this explanation somewhat difficult.