bluuebunny/crossref_metadata_2025 huggingface dataset:
Structures and first-order logic
Authors: Hedman Shawn
Published: November 2020

First-order logic is a richer language than propositional logic. Its lexicon contains not only the symbols ∧, ∨, ￢, →, and ↔ (and parentheses) from propositional logic, but also the symbols ∃ and ∀ for “there exists” and “for all,” along with various symbols to represent variables, constants, functions, and relations. These symbols are grouped into five categories. • Variables. Lower case letters from the end of the alphabet (. . . x, y, z) are used to denote variables. Variables represent arbitrary elements of an underlying set. This, in fact, is what “first-order” refers to. Variables that represent sets of elements are called second-order. Second-order logic, discussed in Chapter 9, is distinguished by the inclusion of such variables. • Constants. Lower case letters from the beginning of the alphabet (a, b, c, . . .) are usually used to denote constants. A constant represents a specific element of an underlying set. • Functions. The lower case letters f, g, and h are commonly used to denote functions. The arguments may be parenthetically listed following the function symbol as f(x1, x2, . . . , xn). First-order logic has symbols for functions of any number of variables. If f is a function of one, two, or three variables, then it is called unary, binary, or ternary, respectively. In general, a function of n variables is called n-ary and n is referred to as the arity of the function. • Relations. Capital letters, especially P, Q, R, and S, are used to denote relations. As with functions, each relation has an associated arity. We have an infinite number of each of these four types of symbols at our disposal. Since there are only finitely many letters, subscripts are used to accomplish this infinitude. For example, x1, x2, x3, . . . are often used to denote variables. Of course, we can use any symbol we want in first-order logic. Ascribing the letters of the alphabet in the above manner is a convenient convention. If you turn to a random page in this book and see “R(a, x, y),” you can safely assume that R is a ternary relation, x and y are variables, and a is a constant.
The Role of Abduction in Logic Programming
Authors: Kakas A. C. , Kowalski R. A.
Published: November 2020

This paper extends and updates our earlier survey and analysis of work on the extension of logic programming to perform abductive reasoning [Kakas et al., 1993]. The purpose of the paper is to provide a critical overview of some of the main research results, in order to develop a common framework for evaluating these results, to identify the main unresolved problems, and to indicate directions for future work. The emphasis is not on technical details but on relationships and common features of different approaches. Some of the main issues we will consider are the contributions that abduction can make to the problems of reasoning with incomplete or negative information, the evolution of knowledge, and the semantics of logic programming and its extensions. We also discuss recent work on the argumentation-theoretic interpretation of abduction, which was introduced in the earlier version of this paper. The philosopher Peirce first introduced the notion of abduction. In [Peirce, 1931-58] he identified three distinguished forms of reasoning. Deduction, an analytic process based on the application of general rules to particular cases, with the inference of a result. Induction, synthetic reasoning which infers the rule from the case and the result. Abduction, another form of synthetic inference, but of the case from a rule and a result. Peirce further characterised abduction as the “probational adoption of a hypothesis” as explanation for observed facts (results), according to known laws. “It is however a weak kind of inference, because we cannot say that we believe in the truth of the explanation, but only that it may be true” [Peirce, 1931-58]. Abduction is widely used in common-sense reasoning, for instance in diagnosis, to reason from effect to cause [Charniak and McDermott, 1985; Pople, 1973]. We consider here an example drawn from [Pearl, 1987]. Abduction consists in computing such explanations for observations. It is a form of non-monotonic reasoning, because explanations which are consistent with one state of a knowledge base may become inconsistent with new information. In the example above the explanation rained-last-night may turn out to be false, and the alternative explanation sprinkler-was-on may be the true cause for the given observation.
Temporal variations in benthic assemblages
Authors: Gray John S. , Elliott Michael
Published: November 2020

Most (but by no means all) benthic species have larval stages which use the water column for dispersal. As indicated in the previous chapter, a key process affecting recruitment to sediment systems is the need to disperse larvae in order to colonize new areas, even to the extent of releasing larvae at spring tides when the tidal excursion will be greatest, thus effecting an even greater dispersal. Seasonal release of larvae is the norm: most species develop gametes in spring and spawn in late spring or early summer (see Rasmussen 1973 for an excellent data set of the times of planktonic larval occurrence and settlement by many important north-west European boreal benthic species). Some species, however, avoid the high competition for food at this time and release gametes in autumn and winter. Thus larvae of benthic organisms are a key and often dominating component of the spring–summer plankton and play important roles as food for planktonic species such as fish larvae. Conversely, a number of planktonic species have resting stages in sediments. The most important of these are undoubtedly the diatoms and many flagellates, and also certain calanoid copepods such as Acartia, which are of course key components of the phytoplankton and zooplankton respectively. Diatom cysts are often found, and there is increased interest in the survival and hatching processes of dinoflagellate cysts that lead to harmful algal blooms. Similarly, the seasonal occurrence of many zooplankton species results from hatching of resting stages in the sediment (see Smetacek (1995), Boero et al. (1996), Pati et al. (1999) and Boero and Bonsdorff (2008) for reviews). The implication of many important planktonic species having benthic resting phases is that by predating cysts, benthic species may be able to control abundances of planktonic species. In this context the meiofauna are important predators (Pati et al. 1999). It is now important to consider the scales of temporal variation in benthic assemblages. First, seasonal changes occur in benthic assemblages of soft sediments even in the depths of the deep sea (e.g. Hsü and Thiede 1992). In spring, as light levels and temperature increase, a plankton bloom occurs.
The soft-sediment benthos in the ecosystem
Authors: Gray John S. , Elliott Michael
Published: November 2020

The benthos does not, of course, live in isolation from other parts of the ecosystem. Here we consider the roles that the benthos plays in the system and how the complex interactions that are found can be modelled using ecosystem models. First, we examine methods that allow us to establish food webs based not only on examining each species in the field and in laboratory feeding studies, but also using stable isotopes of carbon and nitrogen to ascertain the likely feeding mode of a species. It is relatively easy to determine the mode of feeding of some benthic organisms (see for example the excellent review of Fauchald and Jumars 1979, although this is now slightly dated and requires revision). Polychaetes have characteristic feeding structures, so one can determine from their morphology whether they are filter feeders, deposit feeders, or predators. Bivalves show similar morphological characteristics and it is easy to determine whether they are deposit or filter feeders. Some polychaetes have large jaws, e.g. the nereids, and one might assume that they are predators. Yet when Nereis vexillosa was studied in detail (Woodin 1977), it was found that it attached pieces of algae to its tube, which grew and were used for food, so-called ´gardening´. Nereids also are able to filter feed by creating a mucous bag and pumping water through their burrows, which filters the water; the mucous bag is then consumed. More recently, studies have shown varied and possibly opportunistic feeding by different benthic species; for example Christensen et al. (2000) showed how the suspension- and deposit-feeding abilities of nereids influenced sediment nutrient fluxes. These studies show that it is perhaps not so straightforward as once thought to interpret feeding mode simply from morphological features. The definition of functional groups and feeding guilds is increasingly used to help explain and interpret ecological functioning (e.g. Elliott et al. 2007 discuss the rationale behind functional groups). The eminent and immensely experienced benthic biologist Tom Pearson (2001) shows in detail that while the concept of functional groups gives us a greater understanding of the benthos, the idea is criticized by some as we do not have sufficient information about feeding types and modes of life of many benthic species.
Seed dispersal
Authors: Maun M. Anwar
Published: November 2020

Dispersal is a term used for the dissemination of detached reproductive structures from parent plants to a new site. Disseminules include spores, seeds, fruits, whole inflorescences, whole plants, fragments of the parent plant, bulbs and bulbils. Fruit attributes related to a particular dispersal agent or dispersal syndromes are complex and have resulted from millions of years of evolution. In practice, dispersal is mainly local, although some species of sea coasts are well adapted for long-distance dispersal. Knowledge of the modes of plant dispersal is vital to the study of coastal dune ecology because of the clear correlation between diversity and dispersal mechanisms. From the evolutionary point of view, dispersal improves fitness of species: the progeny is able to colonize a new site and extend the range of the species. The fitness here will be defined as getting to a coastal site by using any vector for dispersal, colonization of the new site (germination, establishment and reproduction) and dispersal of the propagules of the immigrant from the new site. Dispersal confers many benefits to the populations of plant species. It reduces competition for limited space and resources in the parental location and the more widely dispersed the propagules, the greater are the chances for the offspring to colonize elsewhere. Dispersal increases the chances of survival and evolution of more fit strains of a species by occupying more diverse habitats than the parents, and speciation may eventually occur in response to new selective pressures. For species adapted to live along sea coasts, dispersal by sea is primarily directed for dissemination to another site by the sea coast. During dispersal several physiological changes may occur in the disseminules that facilitate colonization of the species at the new habitat. For example, Barbour (1972) reported that immersion of upper fruits of Cakile maritima in seawater stimulated their subsequent germination under controlled conditions. Seed coat dormancy may also be broken by abrasion of seeds in sand while being rolled along the sand surface. Considering the large number of species along coasts and on islands, only a very few species may be successfully disseminated in seawater.
The Ammophila problem
Authors: Maun M. Anwar
Published: November 2020

Even a cursory look on foredune plant communities shows vigorous dense stands of dune species in areas with moderate recurrent sand accretion levels specific for each plant species (Disraeli 1984; Maun and Baye 1989; Maun 1998). The phenomenon has been well documented in species of Ammophila arenaria (Carey and Oliver 1918; Tansley 1953), Corynephorus canescens (Marshall 1965), A. breviligulata (Eldred and Maun 1982) and Calamovilfa longifolia (Maun 1985). Burial has a positive influence on growth and flowering of plants and debilitated populations of foredune plant species can be rejuvenated by sand deposition (Maun 1998). Clear evidence of this phenomenon was presented by Maze and Whalley (1992a), who examined population dynamics of Spinifex sericeus in five zones receiving different amounts of sand deposition on a coastal dune system of Australia: the sea side of the first dune ridge, crest of first dune ridge, swale, Acacia thickets and stable hind dunes. In the very dynamic area on the sea side or toe of the first dune ridge (high beach) with regular burial or erosion of up to 1 m or more the plants produced very vigorous stolons with long internodes. On the crest of the dune ridge with sand deposition of about 17.5 cm per year even though plants had fewer stolons, they responded to burial by growing upwards with long internodes. In Acacia thickets in spite of very little sand deposition, plants were vigorous with little or no dead material, produced stolons and grew upwards with some long and some short internodes, probably because of greater nitrogen content in the soil. However, in the swale (slack) with little or no sand deposition, plants showed strong clumping tendency with very short internodes, a large amount of dead material on the surface and very low vigour. Unburied nodes usually died. Similarly, in the stable sand dunes with little or no sand deposition debilitated low-vigour clumps with very few stolons were abundant. Another example of this decline was presented by Martin (1959) on a shoreline along the Atlantic coast of North Carolina. He measured deposition and deflation of sand on two transects and showed that as one moved inland from the shoreline the total deposition of sand decreased.
References and Remarks on the Navier–Stokes Equations
Authors: Chemin Jean-Yves , Desjardins Benoit , Gallagher Isabelle , Grenier Emmanuel
Published: November 2020

The purpose of this chapter is to give some historical landmarks to the reader. The concept of weak solutions certainly has its origin in mechanics; the article by C. Oseen [100] is referred to in the seminal paper by J. Leray. In that famous article, J. Leray proved the global existence of solutions of (NSν) in the sense of Definition 2.5, page 42, in the case when Ω = R3. The case when Ω is a bounded domain was studied by E. Hopf in. The study of the regularity properties of those weak solutions has been the purpose of a number of works. Among them, we recommend to the reader the fundamental paper of L. Caffarelli, R. Kohn and L. Nirenberg. In two space dimensions, J.-L. Lions and G. Prodi proved in [91] the uniqueness of weak solutions (this corresponds to Theorem 3.2, page 56, of this book). Theorem 3.3, page 58, of this book shows that regularity and uniqueness are two closely related issues. In the case of the whole space R3, theorems of that type have been proved by J. Leray in.
Flint and Fauna
Authors: Weiner J. S. , Stringer Chris
Published: November 2020

The manifestly fraudulent elements in the man-ape combination called Eoanthropus dawsoni are the filed down molars and canine, the Vandyke brown staining of the latter and the iron-coloration of the jaw. Taken with the massive evidence of the complete incompatibility of jaw and cranium, those fabrications assure us of the enormity of the larger deception, the foisting of a spurious fossil human ancestor on to the world of palaeontology. The plot achieved its great success because it provided in the spurious fossil a self-consistent array of evidence and this fitted well with the presumed antiquity of the gravels of the Sussex Ouse; for that antiquity there was supporting testimony in the presence of palaeolithic tools and remains of animals of the earliest phase of the Ice Age. But now with the centre-piece proved spurious, what of its appurtenances? Since the jaw is no fossil, but a recent intrusion and a deliberate one, can we help but suspect these other objects in the gravel, impressive and persuasive as the fossil animals and implements appear on first sight? The club-like bone implement discovered in 1914 ranks next to the skull as the most remarkable of the discoveries at Piltdown. Implements of bone are well-known to have been used in the late Ice Age, for example, by men of the cave-art period. Not only is the Piltdown specimen entirely unique in its shape, but as a primitive tool, which Dawson and Woodward were confident it was, it would rank as by far the earliest ever used; in the words of the discoverers, ‘their opinion was that the working and cutting of the bone were done when it was in a comparatively fresh state’. Moreover, Woodward had identified the bone as one which in all likelihood had been obtained from the femur of a very early species of elephant. Judging from the other elephant and mastodon remains, such an animal would certainly have been in existence in the times of Piltdown man.
Clinical detection: ‘information gathering’
Authors: Banerjee Avijit , Watson Timothy F.
Published: November 2020

The oral healthcare team (dentist, nurse, hygienist/therapist/oral health educator, laboratory technician, receptionist, practice manager), led by the principal dental practitioner, should all be involved in the decision-making processes and dental management of the patient, as part of the minimum intervention philosophy of oral/dental healthcare (see Figure 1.1 in Chapter 1). This care rationale is patientcentred, engaging with the patient to encourage them to take responsibility for their own oral health. The role of the oral healthcare team is to provide advice and guidance to help the patient to maintain oral health, as well as providing operative treatment to repair damaged hard and soft tissues. Sometimes the dentist will refer difficult cases to a specialist dentist for their opinion as to what the diagnosis and care plan should be. To manage patients successfully, there are five stages that must be followed (see Figure 2.1):… 1. Detecting clinical problems and their aetiology (see Chapter 2): • This involves detective work to help to gather clinically relevant and useful information, primarily using the skills of verbal history taking, oral examination, and relevant special investigations. 2. Diagnosis and risk assessment (see Chapter 3): • The art of interpretation of signs and symptoms/results from investigations to conclude with identifying the cause of the problem and the potential the individual patient has of developing further disease in the future or responding to treatment. Both aspects are critical to planning the overall care of the patient. 3. Prognosis (see Chapter 3): • The art of forecasting the course of a disease or problem, whether treated or not. 4. Formulation of an individualized patient care plan (see Chapters 3 and 4): • This must be underpinned by the non-invasive control of disease and lesion prevention, following the principles of minimum intervention oral care. • The care plan will also include itemized, costed, minimally invasive operative treatments when required. 5. Recall/re-assess/review (see Chapter 9): • Reviewing the outcomes of any care provided, re-assessing the patient’s response to evaluate whether knowledge/behavioural adaptations and adherence have helped to control and/ or prevent disease reoccurrence, and developing adaptive recall strategies/ intervals that are patient-centred, rather than generic and guideline-driven.
Patterns across the Professions
Authors: Susskind Richard , Susskind Daniel
Published: November 2020

In the previous chapter we describe a wide range of developments across a diverse group of professions. One of our aims in this book is to make sense of the change that is taking place. We tackle this job in various ways. In Part II of the book we offer theoretical accounts of the flux. Before that, our project in this chapter is more practical—to identify patterns and trends that are shared across the professions. In teasing out these patterns and trends, we extend our analysis beyond the largely technological focus of the previous chapter. While we do address the broad implications of these technological advances, we also explore more general movements in professional work. We rely here on insights drawn from our interviews, research, and consulting work. From the last, we gained a sense of the daily preoccupations of the leaders of a sub-set of professional providers (most notably auditors, lawyers, tax advisers, and consultants), who organize themselves in ‘firms’. Some of the trends that we initially identify—relating, for example, to bespoke service, routinization, and decomposition—are given more rigorous treatment in Part II, where we develop a fuller theoretical account of the future of the professions. Accordingly, this chapter should be regarded as a bridge between our findings in the previous chapter and the theory in Part II. In Box 3.1 we summarize the eight broad patterns that we have observed and, for each of these, we pinpoint clusters of more granular trends. Some of these trends overlap and interrelate. We are not offering a taxonomy. At this stage we are instead trying to capture the main features of the flux. Although we advance these patterns and trends in respect of most professions, no individual profession currently displays the full set. Roughly speaking, each of the professions we studied seems to exhibit around half of the trends. It is our hypothesis that over the next decade or two each is likely to take on most of the rest.
Production and Distribution of Knowledge
Authors: Susskind Richard , Susskind Daniel
Published: November 2020

We arrive now at the theoretical heart of the book. In Chapters 2 and 3 we describe how the professions are changing. In Chapter 4 we explain these changes by reference to the information substructure and developments in technology. In this chapter we draw these observations and arguments together. First we develop a model to show how professional work is evolving. Then, building on all we have said and done so far, we step away from the professions and describe the people and systems that will replace them in the future. In broad terms, our focus in this chapter is on the way that we handle a particular type of ‘knowledge’ in society. We are, of course, not alone in exploring this concept. All manner of scholars have applied their minds to ‘knowledge’ over the centuries. Philosophers, for example, who specialize in epistemology ask such fundamental questions as ‘what is knowledge?’ and ‘how can we know anything?’, or again, ‘of what knowledge can we be certain?’ Sociologists study the connections between knowledge and power, culture, and class. Lawyers handle questions about the ownership, protection, and sharing of knowledge. Information theorists consider the relationships between knowledge, information, and data. We are fascinated by each of these perspectives, but for the most part they fall beyond the scope of our work. Instead, the particular type of knowledge that is our preoccupation is what we introduce in Chapter 1 as ‘practical expertise’. Now we explore this concept in greater detail, looking at how we currently create and share it, and how we might handle it differently in the future. We seek to show, in economic terms, that knowledge has special characteristics that make its widespread and low-cost production and distribution both possible, and desirable, in a technology-based Internet society. Practical expertise, or our conception of it, is the knowledge that is required to solve the sort of problems for which the professions, traditionally, were the only solution—the knowledge that is used to sort out a health worry or resolve a tax problem, for example.
Chest pain
Authors: Farne Hugo , Norris-Cervetto Edward , Warbrick-Smith James
Published: November 2020

A good way to come up with a list of causes is to visualize the anatomy of the affected area and think of what could go wrong. Thus, in chest pain, there may be pathology of the heart, aorta, lungs, pulmonary vessels, oesophagus, stomach, thoracic nerves, thoracic muscles, or ribs. The main causes of acute chest pain in an individual aged over 60 include are listed in Figure 9.1. A younger patient is less likely to be suffering from diseases of old age, such as: • Acute coronary syndrome • Stable angina • Myopericarditis (usually post-infarction) • Thoracic aortic dissection • Thoracic aortic aneurysm A younger female patient on the combined oral contraceptive pill is more likely to be suffering from: • PE (the combined oral contraceptive pill is thrombogenic) • Pneumothorax (especially if tall and thin) • Cocaine-induced coronary spasm (still rare, but particularly unusual in older people). The following diagnoses require immediate management and should be kept in mind: • Acute coronary syndrome (unstable angina, or myocardial infarction (MI)) • Aortic dissection • Pneumothorax • PE • Boerhaave’s perforation The key features of each are listed below. 1 Features of acute coronary syndrome ■ History of sudden-onset, central, crushing chest pain radiating to either/both arms, neck or jaw, usually lasting a few minutes to half an hour (longer if there is ongoing infarction). Have a higher index of suspicion in those with a previous history of angina on exertion or MI and/or cardiovascular risk factors (smoking, hypertension, hypercholesterolaemia, diabetes mellitus, family history). ■ Signs of hypercholesterolaemia: cholesterol deposits in small skin lumps on the back of the hand or bony prominences like elbows (xanthomata), in creamy spots around the eyelids (xanthelasma), or a creamy ring around the cornea (arcus). Note that arcus is a normal finding in older people. ■ Signs of peripheral (atherosclerotic) vascular disease: weak pulses, peripheral cyanosis, cool peripheries, atrophic skin, ulcers, bruits on auscultation of carotids. ■ Signs of brady- or tachyarrhythmia. An arrhythmia is relevant for two reasons.
The first religious buildings: ‘sacred huts’
Authors: Potts Charlotte R.
Published: November 2020

The votive assemblages that form the primary archaeological evidence for non-funerary cult in the Neolithic, Bronze, and early Iron Ages in central Italy indicate that there is a long tradition of religious activity in Latium and Etruria in which buildings played no discernible role. Data on votive deposits in western central Italy is admittedly uneven: although many early votive assemblages from Latium have been widely studied and published, there are few Etruscan comparanda; of the more than two hundred Etruscan votive assemblages currently known from all periods, relatively few date prior to the fourth century BC, while those in museum collections are often no longer entire and suffer from a lack of detailed provenance as well as an absence of excavations in the vicinity of the original find. Nevertheless, it is possible to recognize broad patterns in the form and location of cult sites prior to the Iron Age, and thus to sketch the broader context of prehistoric rituals that pre-dated the construction of the first religious buildings. In the Neolithic period (c.6000–3500 BC), funerary and non-funerary rituals appear to have been observed in underground spaces such as caves, crevices, and rock shelters, and there are also signs that cults developed around ‘abnormal water’ like stalagmites, stalactites, hot springs, and pools of still water. These characteristics remain visible in the evidence from the middle Bronze Age (c.1700–1300 BC). Finds from this period at the Sventatoio cave in Latium include vases containing traces of wheat, barley seed cakes, and parts of young animals including pigs, sheep, and oxen, as well as burned remains of at least three children. The openair veneration of underground phenomena is also implied by the discovery of ceramic fragments from all phases of the Bronze Age around a sulphurous spring near the Colonelle Lake at Tivoli. Other evidence of cult activities at prominent points in the landscape, such as mountain tops and rivers, suggests that rituals began to lose an underground orientation during the middle Bronze Age. By the late Bronze Age (c.1300–900 BC) natural caves no longer seem to have served ritual or funerary functions.
The architecture of early shrines and temples
Authors: Potts Charlotte R.
Published: November 2020

The architectural transformations of the seventh and early sixth centuries, often described as the change from huts to houses, generated a range of building types that some scholars have associated with particular types of religious activities. Some small buildings with one or two rooms have been interpreted as oikos shrines; some buildings with multiple adjacent rooms are thought to have been venues for ritual banquets; and some courtyard complexes have been cast as political sanctuaries or residences where the inhabitants observed familial cults. The archaeological evidence for religious activities associated with any of these building types, however, is not straightforward. The first part of this chapter examines whether it is possible to identify any preferred plan for structures that sheltered and complemented religious rituals during the seventh and early sixth centuries BC. The second part then contrasts this inquiry with the relatively straightforward identification of religious buildings during and after the sixth century BC permitted by the introduction of a distinctive, religious architectural marker, namely podia. As such this chapter explores the emergence of a formal architectural vocabulary for Etrusco-Italic religious buildings and identifies when and where cult buildings became architecturally differentiated from other structures within settlements. Although the architectural changes of the seventh and early sixth centuries BC in Latium and Etruria are not linear or uniform, it is clear that round, oval, and rectangular huts with wattle-and-daub walls and thatched coverings were gradually replaced by rectangular structures with stone foundations and tiled roofs. From the middle of the seventh century plans of the new buildings were regularized to the point where it is possible to identify three main types. The names of these types, however, vary both within and between different scholarly traditions, with the result that a rectangular, tile-roofed building thought to have a religious function can be variously labelled an oikos shrine, a proto-temple, or a temple, and a more elaborate building may be described as a Breithaus, a casa a vani affiancati, a courtyard building, a palazzo, a regia, or an elite residence.
Les Pierres de Mémoire: The Life History of Two Statue-Menhirs from Guernsey, Channel Islands
Authors: Sebire Heather
Published: November 2020

Many prehistoric monuments survive in the landscape and are revered by later generations but there is a special category of artefacts and monuments that reﬂect images of ourselves, sometimes with just faces and sometimes as life-size human ﬁgures. On Guernsey, in the Channel Islands, just off the north-west coast of France, two statuemenhirs or standing stones survive that appear to represent female ﬁgures, although the form of the stones themselves may have masculine traits also. Guernsey is the most westerly of the Channel Islands and so it is particularly surprising that these exceptional human representations should be found there (Kinnes 1995). The menhirs have witnessed a long history and have been reﬁgured in modern times possibly in an attempt to Christianize them. One has even been given the local nickname of the ‘Grand Mere’, implying a benign maternal presence. Guernsey is one of a group of small islands that lie strategically placed in the western Channel off the northern coast of France, collectively known as the Channel Islands. The islands of Alderney, Sark, Herm, Lihou and Jethou are part of its Bailiwick, but the largest island of Jersey is independent. Guernsey is positioned some 50 kilometres off the western coast of the Cotentin peninsula of Normandy in France and 120 kilometres from mainland Britain. The Bay of Saint Malo, in which Guernsey and the other Channel Islands are situated, has a very large tidal range due to its position and currents. As a result of this, the inter-tidal zone is extensive. Guernsey is 7.5 kilometres at its widest point and 14 kilometres long, with an area of about 63 square kilometres. This area increases at low tide by some 11 square kilometres. As the great French novelist Victor Hugo famously said, . . . The Channel Islands are fragments of France that fell into the sea and were gathered up by England [ ... ] Of the four islands, Sark, the smallest, is the most beautiful; Jersey, the largest, is the prettiest; Guernsey, wild and charming shares their characteristics. (Hugo 1839, v) . . .
Life and Death of Copper Age Monoliths at Ossimo Anvòia (Val Camonica, Italian Central Alps), 3000 BC–AD 1950
Authors: Fedele Francesco G.
Published: November 2020

During the third millennium BC a widespread Copper Age ideology manifested itself within and around the Alps in ceremonial sites prominently marked by standing monoliths or orthostats (‘statuemenhirs’). The twin valleys of Valtellina and Val Camonica in Alpine Lombardy provide some of the richest inventories of this ideology. The apparent avoidance of anthropomorphism in the Central Alpine monoliths makes them distinct from those of other areas in the Alps and beyond. Combined with an ignorance or neglect of archaeological context (Fedele 2012), this was a reason why the age of the monoliths long remained problematic. From this shared trait and other inter-valley similarities one can envisage a particular ‘Camunian’ province, this adjective being derived from the Augustan name for the Val Camonica polity, the Camunni. In this province the ﬁrst statue-menhirs were discovered between 1940 and 1953 and in the adjacent Adige Basin to the east similar monuments had already been known since the late 1800s, although only published from 1925 (Menghin 1925; Pedrotti 1996). However, not until the ﬁnding and excavation in 1988 of the site discussed in this article, Anvòia, did anyone think that statue-menhirs and associated sites could have a ‘life’ beyond their original time frame: this latter being the Iron Age, as it was initially thought, or the Copper Age as we know now. The occurrence of whole or partial prehistoric monoliths in re-employed conditions—as roadside blocks; in vineyard walls—was considered banal and thus unimportant in archaeological or historical terms. Anvòia initially, and by the late 1990s two other monolith sites in the Val Camonica, Cemmo and Ossimo Pat, suggested instead that an appraisal of the vicissitudes of statue-menhirs after the Copper Age would be of great interest. The case-study presented here provides a demonstration of such possibilities. To avoid the plethora of designations, the general term ‘monolith’ will be used to indicate any kind of individually placed stone of relatively large size, often upright.
Introducing fire
Authors: Scott Andrew C.
Published: November 2020

Fire has a bad reputation. Wildfires raging across parts of California and Australia make headlines. In the news bulletins, it is a destructive force that has to be quenched. But that is far from the whole story. Fire has a long history. In our deep past, wildfire helped shape aspects of our planet, and plants and animals have adapted to it in a variety of ways. In this book, we will follow the story of fire through time. But we begin with the present, with the fires that occur around the world today, and how satellites are changing our view of wildfire. Most of us have little or no experience of a wildfire, apart from those dramatic scenes shown on our television sets from time to time. Almost invariably, two questions are asked: who started the fire, and how quickly can it be put out? Reasonable though they seem, these two questions betray a potential misunderstanding of how fire works on our planet. We assume that the fire was started by humans, either accidentally or deliberately. This may indeed be true, but more than half of the fires started across the globe have a natural cause—mostly lightning strikes, but also other causes such as volcanic activity. Every moment of every day, a fire is burning somewhere in the world. The second assumption is that a fire should always be suppressed. But should we always be rushing to put out a vegetation fire? Wildfire is one of nature’s most frightening manifestations. Winds and storms may die down, and we can seek shelter from them, but fire can be difficult to outrun and escape. Many who are killed by wildfire have underestimated this force of nature, and even those with experience in putting out fires can find themselves cut off, and succumbing to the flames. As we shall discover, not all vegetation burns in the same way, and there are many different kinds of fire, from those burning surface vegetation to those moving through the crowns of trees. Their consequences may also be very different.
Prometheus
Authors: Scott Andrew C.
Published: November 2020

It is sometimes said that humans were born of fire. While a wide range of animal species interact with fire, we appear to be the only species to have learned to tame it, and more importantly to make it. There is evidence that early humans were aware of fire and may have exploited naturally occurring fire, but only later did they control and manage it. Human interaction with fire must have proceeded through various levels, the first of which can be described as the opportunistic phase. In this phase, natural fire may have been exploited to help in hunting, for example. When, how, and why did this happen? It is widely agreed that our story begins in Africa. It is here that we see the evolution of hominins, a group of related genera that include the Australopithecines and later the genus Homo. How common would fire have been in the environments in which they lived? We already know from the study of fossil plants, as well as isotope data, that there were important changes in both the vegetation and climate over the past 10 million years. It is also during this time interval that hominins emerged from apes. Through the Oligocene and Miocene (30–8 million years ago), Africa was largely covered by tropical rainforest, where fire was present but infrequent, started both by lightning strikes and volcanic activity. As the climate began to dry and C4 grasses spread at the end of the Miocene Epoch, around 8 million years ago, habitats became more open. Fire became more frequent, and from an animal perspective would have become more visible, not just from flames but also smoke. Frequent fire in the landscape would have had many consequences for the early hominins, not just because game was more easily killed, but burned animals (naturally cooked meat) would have made a useful addition to the diet, and the new flush of growth following fire would also have attracted large herds of herbivores. Fire may have been conserved through adding fuel, including dung, which is slow burning.
Essentials of Dental Caries
Authors: Kidd Edwina , Fejerskov Ole
Published: November 2020

Dental caries (tooth decay) is one of the most highly prevalent disease around the world affecting a significant proportion of the population. Dental caries may take place on any tooth surface in the oral cavity where dental plaque is allowed to develop over a period of time. Understanding its causes and progression allows the dental team to prevent and manage it so that patients can maintain healthy teeth for life. The fourth edition of Essentials of Dental Caries provides readers with an up-to-date, clinically relevant guide to dental caries. Written in an accessible style, the authors explain the biological and socioeconomic background of lesion development and progress. Current methods of clinical diagnosis and evidence based management are outlined in clearly laid out and highly illustrated chapters. This book is essential reading for students and practitioners of dentistry, dental therapy, dental hygiene, and oral health educators.
Detection, diagnosis, and recording in the clinic
Authors: Kidd Edwina , Fejerskov Ole
Published: November 2020

In Chapter 1 it was stressed that while all dental biofilms exhibit intense metabolic activity, only biofilms where a shift in metabolic activity towards an enhanced acid production over longer periods of time, will result in a net loss of mineral from the underlying tooth surface. The reflection or symptom of this is what can be detected with the naked eye and classified as the caries lesion on the tooth surface. It was pointed out that lesions may be active (if nothing changes in the oral environment, they will progress) or arrested (if nothing changes they will stay as they are). Thus, the things it is necessary to know in order to make an appropriate treatment decision are: ◆ Is a lesion present? This is detection of the lesion. ◆ Is the lesion judged to be active or arrested? This decision, adding the aspect of activity to detection, is diagnosis. ◆ Is the surface of the lesion intact or is a cavity present? If there is a cavity, can the lesion be cleaned by the patient? Diagnosis has been called a ‘mental resting place on the way to a treatment decision’. For instance, grading a lesion as active implies that the clinician considers that, if nothing is done, the demineralization will progress. Figure 3.1 is a decision tree showing how the diagnostic decision may guide the treatment. Thus, the diagnosis detects and excludes disease, assesses prognosis (considering the entire oral condition of the mouth), and forms the basis for the treatment decision. Lesions where the tooth surface is intact can be managed by the patient’s caries control measures. However, a cavity in a tooth may prevent access for the toothbrush. In addition, it may be unsightly and the tooth may be sensitive. These lesions may require restorations as a part of caries control. It is the duty of the professional to discuss with the patient whether any action is required in order to control lesion progression. Finally, the diagnosis should allow the clinical course of the disease to be monitored at subsequent visits.
Communicating with the patient and trying to influence behaviour
Authors: Kidd Edwina , Fejerskov Ole
Published: November 2020

In the previous chapters, the point has been made that dental caries is controllable by the patient regularly disturbing the biofilm, the use of fluoride, especially in toothpastes, and a sensible, but not draconian diet. The success of these strategies depends on the patient, but patients may choose not to comply with the health advice given to them. Many know they should not smoke, should lose weight, and take more exercise, but choose not to alter their behaviour. Altering a patient’s behaviour may be key to caries control, and for this reason all members of the dental team should be interested in strategies to modify behaviour. Motivation is about unlocking the desire within another to make a useful change in behaviour. Good communication is one of the foundations for motivation. Compliance is not likely where patients do not understand, or cannot remember the message. However, people do not change their behaviour just because someone tells them, however clearly, that this is a good idea. Motivation comes from within and cannot just be instilled. It should also be remembered that motivation to change is something that comes gradually, with most people feeling ambivalent about change. Someone who is ambivalent may see a reason to change, but may also see a reason not to change. When we try to persuade someone who is ambivalent to change, the danger is they will resist, giving voice to the counter-argument as to why they cannot change. Actually, the best way to achieve change is if the patient, rather than the health professional, says why and how they should change. In other words, it is their idea and we are there to support it. Despite all these difficulties, good communication can make all the difference in achieving behaviour change and, for this reason, this chapter will now take a detour to discuss aspects of communication. Communication is made up of more than just the actual words used to convey information. The tone used conveys the speaker’s emotions and attitudes, and so-called non-verbal communication or body language can be just as important as the actual words.
The Roman Military Base at Dura-Europos, Syria
Authors: James Simon
Published: November 2020

Dura-Europos, a Parthian-ruled Greco-Syrian city, was captured by Rome c.AD165. It then accommodated a Roman garrison until its destruction by Sasanian siege c.AD256. Excavations of the site between the World Wars made sensational discoveries, and with renewed exploration from 1986 to 2011, Dura remains the best-explored city of the Roman East. A critical revelation was a sprawling Roman military base occupying a quarter of the city's interior. This included swathes of civilian housing converted to soldiers' accommodation and several existing sanctuaries, as well as baths, an amphitheatre, headquarters, and more temples added by the garrison. Base and garrison were clearly fundamental factors in the history of Roman Dura, but what impact did they have on the civil population? Original excavators gloomily portrayed Durenes evicted from their homes and holy places, and subjected to extortion and impoverishment by brutal soldiers, while recent commentators have envisaged military-civilian concordia, with shared prosperity and integration. Detailed examination of the evidence presents a new picture. Through the use of GPS, satellite, geophysical and archival evidence, this volume shows that the Roman military base and resident community were even bigger than previously understood, with both military and civil communities appearing much more internally complex than has been allowed until now. The result is a fascinating social dynamic which we can partly reconstruct, giving us a nuanced picture of life in a city near the eastern frontier of the Roman world.
Crime and punishment
Authors: Copeland Jack
Published: November 2020

In 1952 Turing was arrested and tried for being gay. The court convicted him and sentenced him to chemical castration. It was disgraceful treatment by the nation that he had done so much to save. Turing faced this ordeal with his usual courage. Turing wrote a short story. Although only a few pages long and incomplete, it offers an intimate glimpse of its author. The central character—a scientist by the name of Alec Pryce, who works at Manchester University—is a thinly disguised Alan Turing. Pryce, like Turing himself, always wore what Turing described as ‘an old sports coat and rather unpressed worsted trousers’. Turing called this Pryce’s ‘undergraduate uniform’, saying that it ‘encouraged him to believe he was still an attractive youth’. At just the wrong side of 40, Turing must have been feeling his age. Pryce, whose work related to interplanetary travel, made an important discovery in his twenties, which came to be called ‘Pryce’s buoy’. The nature of the discovery is left unexplained, and Pryce’s buoy is obviously a proxy for the universal Turing machine. ‘Alec always felt a glow of pride when this phrase was used’, Turing wrote revealingly. ‘The rather obvious double-entendre rather pleased him too’, Turing continued. ‘He always liked to parade his homosexuality, and in suitable company Alec would pretend that the word was spelt without the “u” ’. Pryce, we are told, has not had a sexual relationship since ‘that soldier in Paris last summer’. Walking through Manchester, Pryce passes a youth lounging on a bench, Ron Miller. Ron, who is out of work and keeps company with petty criminals, makes a small income from male prostitution. He responds to a glance that Alec gives him as he passes, calling out uncouthly ‘Got a fag?’. Shyly Alec joins him on the bench and the two sit together awkwardly. Eventually Alec plucks up courage to invite the boy to have lunch at a nearby restaurant. Beggars can’t be choosers, Ron thinks meanly. He is not impressed by Alec’s brusque approach and ‘lah-di-dah’ way of speaking, but says to himself philosophically, ‘Bed’s bed whatever way you get into it’.