bluuebunny/crossref_metadata_2025 huggingface dataset:
Program completion in predicate logic
Authors: Hogger Christopher John
Published: November 2023

The construction of the completion Comp(P) when P is a predicate-logic program is slightly more complicated than in the propositional case. Consider first the simplest example in which P comprises just a single ground assertion

The completion must express that ‘q’ holds for ‘a’ and for that term only-that is, (VX)(q(X) iff X=a). The ‘if’ component of the latter sentence is obtained by generalizing the given clause for ‘q’, so that in place of q(a) we write
The completion semantics for finite failure
Authors: Hogger Christopher John
Published: November 2023

The construction of a consequence•-oriented semantics for the finite failure extension is more problematic than for pure Horn-clause programs and queries. In the latter case we have a particularly simple connection between logical meaning and operational meaning:

As soon as we include Jtiil calls in our language no such connection applies--- a program containing fail is not a construct of classical logic and so is not amenable to the notion of classical logical consequence. Nevertheless, a variety of analogous connections have been suggested. The best-known of these is based upon the so-called completion semantics, which relies upon two ideas:
Plausible Inference and Negation in Horn Clause Logic
Authors: Niblett T B
Published: November 2023

We elucidate the role of probabilistic techniques in plausible reasoning and provide reasons why the probabilistic calculus is not adequate by itself for plausible reasoning in expert systems. We suggest a logic-based framework which uses an informal notion of argument as the basis for its representation of certainty. We argue that much of the manipulation of arguments should be done with non-numeric certainties. Probability measures should be introduced only late in the reasoning process, if at all. This scheme is illustrated with examples of the construction and evaluation of arguments. Although much of our work is tentative, we believe that it provides a basis for a well founded knowledge-based approach to plausible reasoning in expert systems.
A Note On First-Order Theories of Individual Concepts and Propositions
Authors: Arbab B
Published: November 2023

Certain classes of sentences when formalized in first-order logic, may give rise to paradoxical conclusions. Within this class are sentences with one or more occurrences of such words as know, believe, aware, discover, and so on. McCarthy (1979) has introduced the first order theory of individual concepts and propositions as a formal language for representing such sentences. McCarthy’s formal language is intended to avoid paradoxical conclusions. This paper presents an example whose formalization in the latter language gives rise to similar paradoxical conclusions.
Learning of Causality by a Robot
Authors: Mowforth P H , Zrimec T
Published: November 2023

This paper describes an experiment in which a robot is allowed randomly to explore the domain of object-pushing via controlled experi ments. The experiments consist of recording signals from sensors before and after an action has taken place. Each experiment may be considered as a state transformation recorded as a sequence of attribute values. Treating each transformation as a training example, a large set of data was collected and subjected to rule induction. Robust and useful trans formations were discovered which were represented as a hierarchical qualitative model. Further, results show that an actor-oriented, co ordinate frame provides the most compact description for the problem. One final observation is that this style of experimentation offers the potential for closed-loop learning in that, unlike other domains, as far as the robot is concerned, its world is the oracle.
Varying Levels of Abstraction in Qualitative Modelling
Authors: Mozetičt I , Institute J Stefan , Bratko I , University E Kardelj , Institute J Stefan , Urbančič T , Institute J Stefan
Published: November 2023

We describe a formalism for hierarchically representing qualitative models at various levels of abstraction. The formalism is based on logic, namely on typed Horn clauses also known as database clauses. The notion of abstraction is realized through a hierarchy of types for the domains of predicates. The abstraction hierarchy can be used in gener ating explanations with an adjustable degree of detail; also in improving search efficiency in solving tasks of diagnosis and control, as well as the learning of qualitative models. Results obtained at a simpler, more abstract level, can be used to guide the search at a more detailed and combinatorially more complex level. The corresponding algorithms are presented as PROLOG programs and their behaviour studied on example problems including a qualitative model of the heart.
PR0M1s: Experiments in Machine Learning and Protein Folding
Authors: Kingt R D
Published: November 2023

The aim of these experiments is to test the use of machine learning as a tool for forming theorie,o, from data. A machine-learning program (PRoMrs) was developed to form rules for predicting protein secondary structure from primary structure-an important unsolved problem in molecular biology. PROMIS uses a top-down controlled hill-climbing beam search with the rules for predicting secondary structure being search states. Structured background knowledge is used to transform the search space and control generalization. Six rules were found that are humanly comprehensible and provide a chemically meaningful descrip tion of the important factors in formation of secondary structure.
Logic and learning: Turing’s legacy
Authors: Muggleton S
Published: November 2023

Turing’s best known work is concerned with whether universal machines can decide the truth value of arbitrary logic formulae. However, in this paper it is shown that there is a direct evolution in Turing’s ideas from his earlier investigations of computability to his later interests in machine intelligence and machine learning. Turing realised that machines which could learn would be able to avoid some of the consequences of Godel’s and his results on incompleteness and undecidability. Machines which learned could continuously add new axioms to their repertoire. Inspired by a radio talk given by Turing in 1951, Christopher Strachey went on to implement the world’s first machine learning program. This particular first is usually attributed to A.L. Samuel. Strachey’s program, which did rote learning in the game of Nim, preceded Samuel’s checker playing program by four years. Neither Strachey’s nor Samuel’s system took up Turing’s suggestion of learning logical formulae. Developments in this area were delayed until Gordon Plotkin’s work in the early 1970’s. Computer-based learning of logical formulae is the central theme of the research area of Inductive Logic Programming, which grew directly out of the earlier work of Plotkin and Shapiro. In the present paper the author describes the state of this new field and discusses areas for future development.
The Discovery of Propositions in Noisy Data
Authors: Tsukimoto Hiroshi , Morita Chie
Published: November 2023

In science, the discovery of propositions in noisy data is important. This discovery is the unsupervised inductive learning with pruning. This chapter presents an efficient algorithm to induce an appropriate proposition from noisy data. A brief outline of the algorithm follows. The frequency data are transformed into a probability vector. The probability vector is transformed into a logical vector. This logical vector is then approximated by a classical logical vector. The classical logical vector is transformed into a logical proposition. This proposition is subsequently reduced to a minimum one. In this algorithm, the most original feature is the pruning method, which is executed at the approximation step. Such pruning is possible due to the transformation from a probability vector to a logical vector. The transformation is possible because (1) a proposition is represented as a vector in Euclidean space and (2) the probability vector can be transformed into a logical vector by a correspondence between the logical vector and the probability vector. Experimental results show that this algorithm performs well and also show that the propositions obtained by the algorithm basically satisfy MDL criteria. We apply this method to some problems to discover appropriate propositions or rules.
Inductive Logic Programming With Large-Scale Unstructured Data
Authors: Bain Michael
Published: November 2023

We report some recent developments from an ongoing project in which a chess endgame domain is providing benchmark experimental tests for the study of concept learning. The King and Rook against King (KRK) endgame is simple enough in chess terms but provides concept learning tasks which can be demanding, as evidenced in previous studies by a number of authors. For learning systems these tasks have highlighted problems of representation, such as the ability to express the structural relationships to be found in learning examples, and other issues like correctness, compression and comprehensibility. Our current focus is on inductive logic programming methods which are based on previously developed systems for the generalization and specialization of normal logic programs. In the current work we are principally concerned with improving these methods to be able to handle more examples during learning. The main contribution of this work consists of a new method of incremental learning, together with new results on a set of concept learning problems taken from the KRK endgame domain.
An experiment with browsers that learn
Authors: Parson Rupert , Muggleton Stephen
Published: November 2023

World Wide Web (WWW) usage is increasing rapidly. Users waste time downloading pages that turn out to have no interest to them. Interesting pages are often overlooked. Modern browsers allow the user to specify search strings. This paper experimentally investigates a different approach based on learning user WWW pages preferences from examples. WWW users were drawn from a class of students. The experiments show that the inductive logic programming algorithm Progol gives overall significant predictive accuracy of user interests. However, the results are highly polarized. Some users are very predictable and others not. The polarization was surprisingly found to correlate in all cases with student exam performance. This work was conducted as part of Parson’s MSc thesis [7].
The spontaneous self-organization of an adaptive language
Authors: Steels Luc
Published: November 2023

The paper studies how a group of distributed agents may spontaneously and autonomously develop a language to refer to other agents in their environment by engaging in a series of language games. The language is adaptive in the sense that it expands or adjusts to the entry of new agents and new meanings. The paper describes the language formation mechanisms and details the results of computational simulations.

The paper proposes a set of mechanisms by which a group of distributed agents may develop autonomously a language for identifying other agents in their environment. The set of agents and the set of features used for making distinctions is open-ended. The language autonomously adapts by the individual actions of agents with only local interactions.
Hollerith and the origins c.1880-1907
Authors: Martin Campbell-Kelly
Published: November 2023

Both IBM and ICL have their origins in the punched-card machines invented by Herman Hollerith in the 1880s. In 1896 Hollerith incorporated a small business, the Tabulating Machine Company (TMC), to manufacture and market his machines in the United States. In 1904 a British operation, The Tabulator Ltd, was formed to develop the punched-card business in Britain; this firm was re-incorporated in 1907 as the British Tabulating Machine Company (BTM). It was from these two firms, TMC and BTM, that IBM and ICL were to evolve.

The tabulating-machine companies were, however, part of a wider industrial phenomenon: the emergence of the office-machine industry, which was really the forerunner of today’s computer and informationsystems industries.
An interlude: the Second World War, 1939-1945
Authors: Martin Campbell-Kelly
Published: November 2023

On 3 September 1939 Britain declared war on Germany, and in December 1941 war was declared upon Japan. Victory in Europe came on 8 May 1945, and Victory over Japan the following August. The six years of war were a hiatus in the economic development of Britain, for in that period everything was sacrificed to the national war effort: ‘Foreign investments were sold, women conscripted, capital was run down and not replaced, civilian consumption was drastically reduced, exports were cut back.’ British industry was in the van of the contribution to the national war effort, and its control over its own destiny was almost completely curtailed.
Rapid growth in a changing market, 1975-1979
Authors: Martin Campbell-Kelly
Published: November 2023

The New Range launch of October 197 4 was, so to speak, only the end of the beginning. There remained the monumental R&D and manufacturing challenge of actually bringing the machines and software into the field. This task was to consume most of ICL’s technical resources during 1975-78.

During this period, however, the market itself was undergoing changes as radical as the transition from punched-card machines to computers in the early 1960s. These changes were in terms of new products, notably small business systems and networks, and new competitors manufacturing IBM-compatible mainframes. The growth that Cross had built into his corporate plan was not, in the event, to prove adequate to sustain the escalating R&D costs. When he left, in December 1977, his successor Chris Wilson would be faced with the problem of how to cover the widening gap between earnings and R&D spending.
Summing up: ICL and the evolving information business
Authors: Martin Campbell-Kelly
Published: November 2023

The concept of an ‘information business’ is a relatively new one. Thus, if we consider the period prior to the Second World War, BTM and Powers-Samas, the forebears of ICL, were considered to be members of the ‘office-appliance trade’: they were viewed as manufacturers of office machines, and that is certainly how they saw themselves. With the merger of the punched-card companies to form ICT in 1959, ICT and its competitors were seen by industrial commentators as being in the ‘computer business’-it was only within the companies themselves that the broader vision of information systems was beginning to emerge. By the 1970s, however, ICL and the other mainstream computer companies were clearly seen as being in the information business: the computer was now regarded as a means to an end, and not an end in itself.
Virus control methodologies
Authors: Louw Eric
Published: November 2023

Chapter 4 laid the foundation of a model for dealing with computer viruses in large organizations. Guided by the structure of Duffy and Assad’s framework for IS security and control, a series of discussions on the various aspects of virus control was presented. These discussions, often drawing on material covered in Chapters 2 and 3, resulted in a number of small frameworks and methodologies. Taken together, these small frameworks and methodologies cover the full range of activities required to set up an effective organizational virus control programme. Each of them, together with the lessons derived from empirical research, constitutes an element in the total methodology presented in this chapter. The intention here is to draw together all this material into practical virus control methodologies for both small and large organizations to use. Before doing this, however, we need to sketch in the typical organizational environment within which these virus control methodologies (VCMs) will have to be planned and implemented.
Feeding and metabolism of Appendicularia
Authors: Deibel D
Published: November 2023

Lohmann (1898, 1899, 1909a, 1933) was the first investigator to recognize the true function of the appendicularian house, which is to concentrate and collect particulate matter from the sea for feeding. He examined the gut contents of Oikopleura albicans and in this way identified an entirely new size class of plankton in the sea, which he called ‘nanoplankton’ (Lohmann, 1909a). The structure of the house is described in detail in Chapter 6; it is remarkably complex and its operation is only well understood in detail in a few oikopleurid species, and less well in a single fritillariid. Essentially, there are in oikopleurids usually three filters involved in food collection; their structure determining the size class of particles a given species can feed upon. The inhalent flow produced by oscillation of the tail draws water into the house via an external relatively coarse filter, then a food collecting filter or trap concentrates particulate material, which is drawn along a short tube to the mouth by the action of spiracular cilia. After entering the pharynx, the particles are trapped on a mucous filter and they enter the oesophagus.
An evolutionary history of British butterflies
Authors: Dennis Roger L H
Published: November 2023

Reconstructing butterfly history is a speculative process, as butterfly fossils are rare, but none the less it is rewarding. First, each butterfly makes a unique set of demands on resources and these taken together with geographical opportunity, account for its distribution. Secondly, a wide array of geological and palaeontological techniques and an abundance of other fossil life-forms have provided a detailed historical template of past environments for butterfly evolution. Thus, data on butterfly biology and geography can be matched against environmental conditions that have changed markedly in time and space (Dennis 1977, in preparation).
Queen-queen conflicts in polygynous societies: mutual tolerance and reproductive skew
Authors: Reeve Hudson K , Ratnieks Francis L W
Published: November 2023

In the years since Williams (1966) argued for an individual-selectionist approach to phenotypic evolution, theorists have steadily lengthened the list of potential conflicts within insect societies, even societies characterized by a high average genetic relatedness. Whenever any genetic heterogeneity exists within colonies, asymmetries occur among colony members in their relatednesses to potential colony propagules (Hamilton 1964). These relatedness asymmetries generate potential conflicts among colony members over who should reproduce and how colony resources should be allocated. Such potential conflicts promote the evolution of manipulative and counter-manipulative reproductive strategies by the parties in conflict.
Monogyny and polygyny in ponerine ants with or without queens
Authors: Peeters Christian
Published: November 2023

The Ponerinae is a phylogenetically primitive subfamily of ants. Bolton (1990a) considers it to be a monophyletic group, although it is morphologically very heterogeneous. Some genera exhibit primitive characters (i.e. similar to hypothesized wasp ancestors), while the morphology of others is considerably derived. Similarly, ponerine life histories and behaviour are a mixture of primitive and specialized traits.
Monogyny and polygyny in Formica ants: the result of alternative dispersal tactics
Authors: Rosengren Rainer , Sundström Liselotte , Fortelius Wille
Published: November 2023

There are two research traditions dealing with the evolution of group-living and sociality in animals. One, originating with Hamilton (1964) and prevalent in social entomology, emphasizes kin selection theory and genetic relatedness. The other, emanating from research on the social ethology of vertebrates (e.g. Crook 1964), has stressed the importance of ecological correlates. This ecological approach to sociality uses evidence from different animal species, including primates, to show that a philopatric tactic in offspring due to clumping of resources, risky dispersal, and/or resource inheritance may have preceded the evolution of co-operation (Waser 1988; Myles 1988).
The Lesser Snow Geese Of La PéRouse Bay
Authors: Lank David B , Rockwell Robert F
Published: November 2023

We originally chose to work with Lesser Snow Geese, Anser caerules- cens caerulescens, the smaller subspecies of the Snow Goose, because it has a conspicuous plumage dimorphism. The Latin nominate refers to the blue phase, formerly known as the Blue Goose, with grayish brown feathering on most of the body and a white head. The English nominate refers to the white phase which is all white, except for its black primary feathers (Fig. 2.1). We were initially interested primarily in how this polymorphism was maintained. We were also interested in the fact that the population showed positive assortative mating, which we hypothesized to be a result of birds choosing mates of the same plumage colour as their parents.
Fitness Components Model Of Snow Goose Life Cycle
Authors: Lank David B , Rockwell Robert F
Published: November 2023

Closing his chapter ‘Struggle for Existence’, Charles Darwin (1859) gave his view of fitness by stating ‘... that the vigorous, the healthy, and the happy survive and multiply’. An individual’s relative fitness is measured by its ability to pass copies of its genes to the next and future generations compared to other members of its population. While the concept is straightforward, many would agree with Lewontin’s (1974) statement that ‘Although there is no difficulty in theory estimating fitnesses, in practice the difficulties are virtually insuperable’. A major advance towards measuring fitnesses under real world conditions was made by Prout (1969, 1971) who partitioned fitness into its two basic components, namely, viability and fecundity, and evaluated each separately, as well as the interactions between the two. This approach brought analytical and empirical research on fitness back to Darwin’s original duality of ‘survive and multiply’. Bungaard and Christiansen (1972) and Christiansen and Frydenberg (1973) furthered this approach, adding components for sexual and gametic fitness and stressing the need to evaluate fitness with components that correspond to stages of the life cycle of the species being studied. Arnold and ⩖ade (1984a,b) refined and extended the approach to polygenic phenotypes and stressed Prout’s (1965) point that the components and stages must be assessed within a single generation. Hedrick and Murray (1983) provide a particularly lucid overview of both the basis and application of the components of fitness approach.
Pairing, Mating, And Parental Care
Authors: Lank David B , Rockwell Robert F
Published: November 2023

The complexities of reproductive strategies in long term socially monogamous birds such as geese, in contrast to the more obvious ones in polygamous species, have only recently been appreciated by ornithologists. Young Snow Geese find mates during their second winter or spring, and establish pair bonds which nearly always are maintained until the death of a partner. The pair typically migrate to breeding grounds, breed, and migrate back south together for years. This chapter focuses on variation in five aspects of reproductive behaviour which themselves affect fitness, and which also potentially affect interpretations of the reproductive components of fitness defined in the previous chapter and used in subsequent analyses. We discuss mate choice, pair-bond duration, mate fidelity, intra-specific nest parasitism, and aspects of parental care.
Morphology, domestication and moult
Authors: Zann Richard A
Published: November 2023

Australian Zebra Finches are significantly bigger than Lesser Sundas Zebra Finches (Clayton et al. 1991). Samples from northern Victoria (Danaher colony) in southeastern Australia were heavier (males 1 g heavier on average, females 1.5 g) than those trapped on Lombok, Sumbawa, Flores and Timor; wings and bills were also longer (5 mm and 1 mm on average, respectively). Bill-depth was significantly smaller only in the Flores and Timor samples (Figure 3.1). Bills of Australian males were redder, darker and more intensely coloured than those from the Lesser Sundas, but there were no significant differences between females. Within each subspecies the bills of males are, on average redder, darker and more intense than those of females which are an orange-red colour. Considerable overlap exists in bill colour of the sexes (Burley and Coopersmith 1987). Detailed comparisons of iris colour of the two subspecies have not been made but both are a deep reddish orange in wildcaught birds, but a dark brown in aviary-bred ones.
Drinking, water relations and temperature regulation
Authors: Zann Richard A
Published: November 2023

Although Zebra Finches have become one of the symbols of the Australian arid zone, they are not considered among the true desert specialists that have evolved in the deserts and can live nowhere else (Frith 1973; Schodde 1982). Zebra Finches are among a number of species, including many granivores, that have more widespread distributions and have penetrated the deserts from surrounding semiarid regions. Selection in these species has tended to favour flexibility rather than specialisation, and this strategy is exemplified in the adaptations and pre-adaptations of Zebra Finches to the three main elements of desert environments – dryness, heat and cold.
Vocalisations
Authors: Zann Richard A
Published: November 2023

The Australian subspecies of Zebra Finch is highly vocal, and in the wild one usually hears them before seeing them. They have ten or eleven distinct calls in addition to the song. The Lesser Sundas subspecies may have a similar number, but to date, only the song and three calls have been described. In general, aviary-bred Lesser Sundas Zebra Finches are less vocal (both songs and calls) than their Australian counterparts in both aviaries and cages. The sounds of each subspecies are qualitatively distinct: Lesser Sundas birds have a high-pitched whistle while Australian birds have a heavy nasal twang.
Introduction
Authors: Hassell Michael P
Published: November 2023

For much of this century, insect ecologists have questioned what determines the abundance and patterns of fluctuation of insect populations. In a prescient study on the gypsy moth and brown tailed moth, Howard and Fiske (1911) made the first clear statement on the types of factors affecting the population dynamics of insects. Only one kind of mortality factor, their facultative agencies, was thought to maintain a ‘natural balance’ (i.e. equilibrium) by causing ‘the destruction of a greater proportionate number of individuals as the insect in question increases in abundance’.
Multispecies host-parasitoid systems
Authors: Hassell Michael P
Published: November 2023

The vast majority of insect hosts, especially in natural habitats, are attacked by more than one parasitoid species, and most parasitoids will attack more than one host species. The population dynamics of natural host-parasitoid systems will therefore not be properly understood without facing up to the complexities of multispecies interactions. Our current understanding of host–parasitoid population dynamics comes largely from models of two- and three-species interations.
Epilogue
Authors: Hassell Michael P
Published: November 2023

The question of what regulates populations was first posed early in this century by entomologists, particularly Howard and Fiske (1911) and Thompson (1924) who were engaged in the design and execution of biological-control programmes, and by Nicholson (1933) who was interested in more general questions of population dynamics. Thompson and Nicholson’s models were both framed in discrete generations and had random parasitoid encounters with hosts, but they made quite different assumptions about the efficiency of parasitoids in finding hosts. Thompson’s parasitoids were always egg-limited and his models were inherently unstable. Nicholson’s parasitoids had a potentially unlimited egg supply and were only limited by their searching ability, encapsulated in the searching efficiency parameter, the area of discovery. Ironically for someone who championed the cause of population regulation by density-dependent factors, his models were also unstable showing divergent oscillations in host and parasitoid population densities.
Vanishing Rain Forests
Authors: Aiken S Robert , Leigh Colin H
Published: November 2023

Malaysia is one of the world's most biologically diverse regions, but in recent years vast tracts of its forests have been cleared or degraded, with serious human and environmental consequences. Vanishing Rain Forests explores four closely related themes: first, it describes the country's forests and the remarkable abundance and diversity of their flora and fauna; secondly, it outlines the processes and policies by which human activity has altered these forests since the early nineteenth century; thirdly, it examines some of the environmental, biological, and cultural consequences of such changes both past and present; and finally, it looks at what has been done to conserve the region's natural wealth and recommends changes that could put Malaysia on the path to a more sustainable future. Throughout the book the need for a historical perspective is underscored.
Conservation: Towards A Sustainable Future
Authors: Aiken S Robert , Leigh Colin H
Published: November 2023

The Malay Archipelago has long been famed for its natural wealth. It was the lure of gold and tin and the riches of the forest and the sea that for some two millennia or more drew Arab, Indian, and Chinese traders to regions like the Malay Peninsula and the coasts of Borneo; and it was from the abundant harvest of natural resources that early maritime kingdoms and empires drew much of their wealth.
The insulin-like growth factor binding proteins: structure and biological functions
Authors: McCusker Robert H , Clemmons David R
Published: November 2023

The regulation of cellular metabolism and its link to changes in cellular proliferation is an area of active investigation. An increase in the cellular metabolic rate with an ensuing increase in cell size are prerequisites for cytokinesis. Numerous peptide growth factors have been identified that modulate both of these processes. Cellular responsiveness to these factors is controlled by several means including (i) the concentration and avail ability of the growth factor in biological fluids; (ii) the presence and abundance of cell-surface receptors, which for peptide growth factors are generally integral plasma-membrane proteins; (iii) the integrity of post receptor transmembrane signalling mechanisms; and (iv) transcriptional regulatory mechanisms.
The involvement of insulin-like growth factors in embryonic and fetal development
Authors: Han V K M , Hill D J
Published: November 2023

The insulin-like growth factors (IGFs) have a wider anatomical and de velopmental range of gene expression and peptide presence than any other known peptide growth factor. This implies that they may serve as a basic stimulus to embryonic and fetal growth. Critical analysis of the literature comfirms that a close relationship does exist between IGFs and growth, but the exact nature of their biological action and physiological regulation of IGF synthesis remain elusive. The purpose of this chapter is to define the points at which experimental observations currently end, and are replaced by suppositions. Experimental and clinical observations have, one hopes, progressed to a point where some coherent hypotheses can be formulated. The biological role of IGF-I (or somatomedin C) in postnatal growth is well established (Humbel 1984; Van Wyk 1984; Zapf et al. 1984). The human pubertal growth spurt results from increased secretion of growth hormone by the anterior pituitary, mediated by systematically or locally synthesized IGF-I, which then acts on the proliferating chondrocytes of the long-bone growth-plates (see review by Isakson 1987; and Chapter 9). How ever, the role of IGF-II is still not clear. Data showing high concentrations of peptide and mRNA in utero suggest that IGF-II may be important during fetal life in rodents (Moses et al. 1980) and man (Han et al. 1987a, 1988). The biological actions of IGFs are mediated by two types of cell-surface receptors, termed the type 1 and type 2 IGF receptors (see review by Nissley and Rechler 1984b). Current evidence indicates that the expression of functional IGF receptors during embryogenesis is an important prerequisite in the regulatory actions of JGFs. In addition, however, the actions of IGF are modulated by another group of proteins called binding proteins (BP) (see review by Hintz 1984; and Chapter 6), which are abundant in the embryo and fetus.
Insulin-like growth factors human cancer
Authors: Schofield Paul N , Engstrom Wilhelm
Published: November 2023

One of the first observations to indicate a role for growth factors in the development of cancer was that transformed or tumour-derived cell lines required less serum for proliferation in vitro than their normal counterparts (reviewed by Engstrom and Zetterberg 1983). From these early reports emerged the concept that the reduced requirement for serum resulted from de nova synthesis of polypeptide growth factors by the tumour cells them selves. Subsequent analysis of the endogenous growth-factor synthesis resulted in the isolation of the transforming growth factors-a and -13, as well as sets of other growth-regulatory molecules and their receptors (see Sporn and Roberts (1985) for review), some of which had been previously characterized as transforming oncogenes (Doolittle et al. 1983; Waterfield et al. 1983; Downward et al. 1984; Dickson and Peters 1987; Taira et al. 1987). Of particular importance was the finding that the transforming growth factors as well as a variety of other tumour-derived growth factors were normal gene products.
Trees of Nigeria
Authors: Keay R W J
Published: November 2023

Nearly a thousand species of trees found in Nigeria, including many of the introduced species, are listed and described in this book. It presents a revision of Nigerian Trees (1960, 1964) and includes all subsequent changes in nomenclature and classification as well as some 1500 vernacular names and vocabularies. This book will be of value to botanists generally, and to all who are concerned with West African plants, especially to those in forestry, agriculture, and wildlife services. Ecologists, conservationists, and those with a more general interest in the environment will also find it a valuable reference source.
Vascular development
Authors: Tomlinson P B
Published: November 2023

Having deciphered the method of construction of the vascular system in palm stems, it is necessary to understand the principle of development. This requires an analysis of the origin of the vascular bundles in the palm crown as they connect to the developing leaves, initially, as procambial strands and, subsequently, as the provascular system that serves as a template for the differentiation of xylem and phloem. The extent of this analysis is considerable, even in a small palm, since tissues mature progressively over long distances. Figure 8.1, for example, shows a scale diagram of the developing region of a Rhapis stem, used in the detailed plots described later. Incompletely differentiated regions are hatched. The region is divided into two segments, the crown proper and the lower extending portion. The crown includes a portion of the axis and the base of attached leaves. Leaves and associated internodes are unextended. The size of the crown depends on the vigour of the shoot. A series of stained paraffin section is used to plot the course of individual bundles (e.g. Figs 8.2, 8.9) by the optical method described in Zimmermann and Tomlinson (1967). The lower segment represents the axis below the level of insertion of the youngest visible expanded leaf (1) with each internode below the first four leaves (1-4) still extending. This longer segment is analysed in sequential sections cut from the unembedded stem by means of a sliding microtome. In this example internodes below leaf 5 onwards have reached their mature length, as determined largely by the existence of mature metaxylem. It should be emphasized that internodes are not of equal length, which is why older internodes can be drawn shorter than younger ones. One can conclude, and dye ascent experiments can verify, that leaves 1-4, all of which have expanded photosynthesizing blades, are supplied with water through protoxylem elements only, since their associated internode and part of the leaf base has still to complete maturation of metaxylem. The leaf trace system to any one expanded leaf can be located with complete precision prior to sectioning by allowing an aqueous dye (e.g. either decolourized gentian violet, or Schiff’s reagent) to be drawn through the petiole of a cut leaf by a slight vacuum applied to the cut stem surface—a dye descent experiment (Fig. 8.9). Major traces of a given leaf can then be recognized by the movement of the dye into their xylem elements.
The Comparative Method in Evolutionary Biology
Authors: Harvey Paul H , Pagel Mark D
Published: November 2023

From Darwin onward, it has been second nature for evolutionary biologists to think comparatively because comparisons establish the generality of evolutionary phenomena. Do large genomes slow down development? What lifestyles select for large brains? Are extinction rates related to body size? These are all questions for the comparative method, and this book is about how such questions can be answered. The first chapter elaborates on suitable questions for the comparative approach and shows how it complements other approaches to problem-solving in evolution. The second chapter identifies the biological causes of similarity among closely related species for almost any observed character. The third chapter discusses methods for reconstructing phylogenetic trees and ancestral character states. The fourth chapter sets out to develop statistical tests that will determine whether different characters that exist in discrete states show evidence for correlated evolution. Chapter 5 turns to comparative analyses of continuously varying characters. Chapter 6 looks at allometry to exemplify the themes and methods discussed earlier, while the last chapter looks to future development of the comparative approach in both molecular and organismic biology.
Determining the forms of comparative relationships
Authors: Harvey Paul H , Pagel Mark D
Published: November 2023

Allometry has been variously defined as ‘the study of size and its consequences’ (Gould 1966, p. 587), ‘the biology of scaling’ (Calder 1984, p. 1), the study of ‘the structural and functional consequences of changes in size or scale’, (Schmidt-Nielsen 1984, p. 7), and perhaps more daringly as ‘the study of the relationship between size and adaptation’ (Fleagle 1985, p. 1). What is at issue in each of these quotations is the pervasive tendency for a variety of morphological, physiological, life history, and behavioural characteristics of organisms to show highly regular changes with changes in body size. Allometry is used to describe such relations quantitatively, and we use it here to illustrate a situation in which the comparative biologist’s primary interest is not in whether a relationship between two variables exists but in the form that the relationship takes.
Food and feeding behaviour
Authors: Hulscher Jan B
Published: November 2023

Oystercatcher species throughout the world are bound to the sea-shore (Voous 1965). At the most, they breed 400 km inland and return to the coast immediately afterwards. In coastal regions, Oystercatchers chiefly feed in the intertidal zone. All species share the habit, unique amongst waders, of opening lamellibranchs with their stout, laterally compressed bills. As they only eat the flesh, they are able to feed on the larger-sized prey individuals. Other mollusc-eating birds swallow their prey whole, the dimensions of their throat restricting them to the smaller size classes of prey. As molluscs often make up the bulk of the benthic biomass in intertidal areas, especially in winter (Beukema 1976, 1982), selection may favour Oystercatchers because of their ability to exploit a large pro¬ portion of the biomass of some very abundant prey organis’ms that are inaccessible to other species. This too, no doubt largely explains why Oystercatchers are relatively numerous amongst carnivorous birds on intertidal flats. This chapter briefly details the habitats where Oystercatchers live and their main prey species. It then explores the formidable and subtle capabilities with which these sturdy birds are able to exploit their feeding grounds.
The earliest proboscideans: general plan, taxonomy, and palaeoecology
Authors: Shoshani Jeheskel , West Robert M , Court Nicholas , Savage, Robert J G , Harris John M
Published: November 2023

This chapter includes updated synthesized information on the earliest proboscideans—Anthracobune, moeritheres, numidotheres, barytheres, and deinotheres. Palaeomastodon Andrews, 1901a, and Phiomia Andrews and Beadnell, 1902, are excluded from the description (they are included in Figs 8.1 and 8.2) because, based on the available evidence, they are classified within a well-defined suborder Elephantiformes Tassy, 1988a, whereas Anthracobune, Moeritheriidae, Numidotherium, Barytheriidae, and Deinotheriidae each represent a unique clade at the beginning of this cladogram prior to the appearance of Elephantiformes. In addition, anthra-cobunids, Moeritheriidae, Barytheriidae, and Deinotheriidae have been included or excluded from the Proboscidea (details in Tassy 1985, 1990a; Shoshani 1986b). A better understanding of these five lineages is therefore needed, for they may shed light on the relationships of more advanced proboscidean taxa, especially if there was a closer association among Numidotherium, Barytheriidae, and Deinotheriidae, or between Barytheriidae and Deinotheriidae, as some authors have suggested (Harris 1978; Mahboubi et al. 1986; Savage and Long 1986; Savage and Court 1989; Tassy 1990a, this volume, Chapter 6).
Extinction of proboscideans in North America
Authors: Fisher Daniel C
Published: November 2023

The history of proboscideans in North America begins with the immigration of mammutids and gomphotheriids from Eurasia in the middle Miocene (c. 15.5 Ma). It is marked subsequently by phyletic change, additional immigrations (of amebelodontids and elephantids), origins of new lineages, and extinctions of existing ones, but this pattern came full circle about 10 000 years BP, with the final disappearance of proboscideans from this continent. In some respects it is artificial to treat this history apart from that of South America, whose proboscidean fauna was derived from North America, or apart from that of Africa and Eurasia, where proboscidean faunas experienced somewhat parallel changes, but extinction is an ecological process, taking place within spatiotemporally bounded systems. The North American segment of the proboscidean record may thus be treated as an informative subset of their broader history.
Form and function
Authors: Pratt H Douglas , Jeffrey Jack , Conant Sheila
Published: November 2023

The postcranial (body) anatomy of Hawaiian honeycreepers is surprisingly uniform for such a diverse group. Early workers found little in the body skeleton of Hawaiian honeycreepers that differed in any noticeable way from that of most perching birds. James and Olson (1991), in fact, report that most of the postcranial bones found in prehistoric deposits cannot be identified to species unless part of an associated skeleton.
Statistical Analysis of Behavioural Data
Authors: Haccou Patsy , Meelis Evert
Published: November 2023

Presenting sophisticated statistical methods for analysing continuous-time records of behaviour, this book integrates recent developments in ethology, mathematical modelling, statistics, and technology. With numerous worked examples, the book leads the reader through the mathematical processes and their applications. The book will be incomparably useful to students and researchers in all areas of behavioural science. The authors show how to analyse behavioural data starting with a basic model, the continuous-time Markov chain. They then indicate how and when this model can be generalized and demonstrate the suitability of their approach for detecting, for example, the effects of different experimental treatments or of changes in the social or physical environment. Competitive interactions such as predator-prey or host-parasite are also good subjects for this type of analysis.
Distribution and habitat
Authors: Short Lester L , Horne Jennifer F M , Gilbert Albert Earl
Published: November 2023

We here set forth the highlights of the generally tropical distributions of barbets, toucans and honeyguides, some aspects of their zoogeography and species formation, the occurrence together and apart of closely related species, observations or replacement of closely related species from lowlands into mountains, effects of vegetation and climate on distribution, terms applied to vegetation in this volume, and the major aspects of conservation of these birds.
Ramphastidae — toucans, aracaris, toucanets
Authors: Short Lester L , Horne Jennifer F M , Gilbert Albert Earl
Published: November 2023

All green generally with toucan bill of black and yellow, the only green toucan in its Central American range. In NW South America distinguished from other green toucanets by its black and yellow bill; south of Ecuador has blue or black throat, unlike other congeners there.
Silvicultural Systems
Authors: Matthews John D
Published: November 2023

There is a rapid rate of forest clearance in many tropical countries. This problem is becoming more serious as the rising world population increases demand for fuelwood and timber. The reduced area of forest must be treated so as to produce the highest possible sustained yield of suitable timber compatible with protecting the environment and water supplies, conserving wild life, enhancing attractive scenery, and giving opportunities for recreation. In Europe complete regimes for regenerating, tending, and harvesting forests called "silvicultural systems" have provided effective solutions to these problems. These are being used successfully in temperate, sub-tropical, and tropical forestry, often under conditions very different from those in which they originated. This book describes the theoretical basis and practical application of 20 silvicultural systems so that foresters and other land managers, ecologists, and landscape designers can select and use those best suited to their needs.
Introduction
Authors: Matthews John D
Published: November 2023

A silvicultural system may be defined as the process by which the crops constituting a forest are tended, removed, and replaced by new crops, resulting in the production of stands of distinctive form (Fig. 1). In this definition ‘tending’ refers mainly to thinning operations done in immature crops, in so far as these operations affect the state of the crop and soil at the time of regeneration.
The protective functions of managed forests
Authors: Matthews John D
Published: November 2023

As already noted, the functions of managed forests may be classified as productive, protective, and social. The most important productive functions are to sustain supplies of timber and minor products, such as foliage, fruits, honey, dyes, and medicinal plants. The protective functions are concerned with the environment and take several forms, including: (1) protecting the physical features of the land; (2) regulating the quantity and quality of water supplies; (3) conserving wild plants and animals through management of their habitats; and (4) protecting landscapes of outstanding natural beauty.