bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationships and origin of the Palmae
Authors: Tomlinson P B
Published: November 2023

The true palms traditionally have been thought to be related to certain other groups of woody monocotyledons, notably the Pandanaceae, Cyclanthaceae, and Araceae, largely on the basis of superficial similarity of either habit or reproductive structure that is seen to be misleading on detailed examination (Fig. 16.1). In some instances the putative similarity is based on a quite elementary misconception of morphological features, as that which attempts a comparison of inflorescences in Araceae and Palmae simply because the terms ‘spadix’ and ‘spathe’ have been used descriptively for the two families. The disposition of major reproductive units in the two groups is, in fact, quite different. These four families of tropical monocotyledons are easily distinguished by combinations of gross morphological features as well as in anatomy, substantiated by evidence from other disciplines (Tomlinson and Wilder 1984). The Araceae are treated without the anomalous genus Acorus whose affinities are still obscured.
Aspects of aroid geography
Authors: Mayo Simon J
Published: November 2023

It would be understandable if the reader were puzzled to find in the present volume a discussion of a family of organisms which shows only weak and distant relationships across the South Atlantic Ocean. There are, after all, many other tropical plant taxa which show striking disjunctions between Africa and South America (Thorne 1973a and Good 1974 give lists of genera). In at least a proportion of these cases, such disjunctions are probably evidence of previous land continuity between the continents. There are, nevertheless, good reasons for considering the geographical patterns shown by taxa which do not fit neatly into the simple vicariance model represented by the tectonic splitting of South America and Africa.
Comparative analysis of discrete data
Authors: Harvey Paul H , Pagel Mark D
Published: November 2023

In this chapter we consider methods for the comparative analysis of discrete characters, or characters that can take only a finite number of states. The methods that we review and develop address the analysis of dichotomous characters—that is, characters that are found in just two states. However, this does not impose any limitations because any multicategory discrete variable can always be represented as a set of dichotomous classifications, each one representing the presence or absence of a particular state. In each branch of the phylogenetic tree, a trait that is initially absent may evolve or a trait that is initially present may disappear. These changes along the branches are called character state transitions or just transitions. The problem, then, is to determine whether a particular pattern of observed transitions between alternative states of two phenotypic characters throughout a phylogenetic tree represents correlated evolutionary change in the two characters, or just a chance pattern of association.
Palaeobiogeography of late Neogene African and Eurasian Elephantoidea
Authors: Kalb Jon E , Froehlich, David J , Bell Gorden L
Published: November 2023

INTRODUCTION

Our cladistic analysis of late Miocene to Pleistocene proboscideans presented in this volume (Kalb et al., this volume, Chapter 12A) allows us new insights on the temporal and palaeogeographical distribution of late Neogene elephantoids, as summarized in Figs 12B.l and 12B.2 (cf. Kalb 1995). The terminology and taxa discussed in this chapter are described in detail in the text and in Appendix 12A.l of Chapter 12A. This report is not intended to be an exhaustive account of the palaeobiogeography of late Neogene elephantoids, rather we will address only dates and faunal patterns that bear on our particular cladistic analysis. In our discussion, Neogene epoch and European stage boundaries are based on Harland et al. (1990, fig. 3.15) (Fig. 12B.1); supplementary references are noted as necessary.
Sexual dimorphism in the mammoth pelvis: an aid to gender determination
Authors: Lister Adrian M
Published: November 2023

Determining the gender of fossil proboscidean skeletons can make an important contribution to understanding their taphonomy. This is particularly the case among members of the Elephantidae, where fossil species can be assumed to have had a broadly similar social structure to that of the living elephants (Haynes 1991). For example. mammoth assemblages such as Lehner Ranch, Arizona, thought to result from the slaughter of matriarchal groups, are expected to be dominated by females, as in living elephant species (Saunders 1980). At others, such as Hot Springs, South Dakota, the predominance of young adult males is believed to result from a gradual accumulation of individuals as these roving, adventurous animals became caught in a natural trap (Agenbroad and Mead 1987a).
North American Mammutidae
Authors: Saunders Jeffrey J
Published: November 2023

The North American diversification of elephantoids included representatives of the families Mammutidae, Amebelodontidae, Gomphotheriidae, and Elephantidae (Simpson 1945; Tassy 1985). North American records of these families resulted from one immigration of gomphotheriids (Gomphotherium), two of amebelodontids (Amebelodon, Platybelodon), and one of mammutids (Miomastodon) in the Miocene and two of elephantids (Mammuthus meridionalis, Mammuthus primigenius) in the Pleistocene.

This chapter, focusing on North American mammutids, is a synthesis based in part on recent and ongoing work by the author and collaborators on late Pleistocene Mammut americanum (Saunders 1977; King and Saunders 1984; Saunders and Tassy 1989). (Hereafter, Mammut americanum is abbreviated as M. americanum.) Present in North Africa and Europe in the early Miocene (Rusingan and Orleanian mammal ages, respectively; Savage and Russell 1983; Tassy 1990b), gomphotheriids and mammutids appear in North America as immigrants utilizing the Bering Strait in the middle Miocene, c. 15.5 Ma, during the early (Green Hills Fauna phase) Barstovian Mammal Age (e.g. Gomphotherium calvertense, Miomastodon merriami) (Tedford et al. 1987). After a consideration of distinguishing features, this chapter presents a brief overview of the preservation mode of North American Tertiary mammutids and contemporary elephantoids and discusses trends in the history and evolving role of later mammutids that are represented by abundant, well-preserved material.
Movement, drinking, roosting, display, sociality and interspecific behaviour
Authors: Short Lester L , Horne Jennifer F M , Gilbert Albert Earl
Published: November 2023

Aspects of behaviour not related to breeding and feeding are discussed here. Movements on the ground or in trees usually are by hopping. Flight is sometimes undulating as in woodpeckers, but usually is slow and laboured, due to the short wings of barbets and toucans.
Permian
Authors: Guirong Xu , Weiping Yang
Published: November 2023

The basic map of Permian palaeobiogeographical provincialization of the world used in this chapter is by Scotese et al. (1979) with a modification of the Chinese part according to Chinese palaeomagnetic and palaeoclimatic inforn1ation, discussed in detail in this chapter and Chapter 15. Palaeolatitudinal locations for South and North China have been fixed to a high degree of reliability, and for Tarim, Siberia, and Tibet to a lesser degree (Khramov et al. 1981; Chen et al. 1983; Bai et al. 1985; Lin et al. 1985; Zhao and Coe 1989; Nie et al. 1990). South China was near the equator while North China was about 10°-20°N, Tarim was about 30°N, and Himalaya about 20°S.
Effects of burrowing macrofauna on organic matter decomposition in coastal marine sediments
Authors: Andersen Frede Østergaard , Kristensen Erik
Published: November 2023

Burrowing macrofauna may, by activities such as burrowing and feeding (‘reworking’), redistribute organic matter deposited or produced at the surface layer of aquatic sediments. Infauna! ventilation of water through burrows is responsible for an active transport of solutes into and out of the sediment. The metabolism of benthic communities (measured as oxygen uptake and carbon dioxide release) is often increased 1.5-3.0 times by the presence of burrowing macrofauna. Most of this is due to a general stimulation of heterotrophic micro organisms in the sediment and only to a minor degree caused by macrofaunal respiration. Accordingly, high ,microbial and catalysing enzyme activity is usually associated with burrow structures and faecal casts.
The European Discovery of the Indian Flora
Authors: Desmond Ray
Published: November 2023

The flora of the Indian subcontinent has stirred European curiosity and investigation for over two millennia. From pepper, a coveted commodity of the lucrative spice trade, to rhododendrons, orchids, and alpine flowers, cherished in innumerable British gardens and conservatories, Indian plants have long been highly prized in the West. This book surveys European perceptions of the diversity of the Indian flora, and examines its impact on European commerce and culture including botany, horticulture, and floral art. It chronicles the growing European awareness of the Indian flora from the first glimmerings of knowledge in the fifth century BC to the demise in the mid-nineteenth century of the British East India Company and of its successor, the India Office. An epilogue briefly surveys the development of botanical studies since the independence of India and Pakistan in 1947. The evolution of European-style gardens in India is examined, and the impact of the Indian flora on British gardens is assessed.
Pharmacokinetics, placental transfer, and teratogenicity of 13-cis-retinoic acid, its isomer and metabolites
Authors: Kraft Joan Creech
Published: November 2023

Retinoids, which normally have important physiological functions, are also used in clinical medicine. 13-cis-retinoic acid (Accutane, isotretinoin, 13-cis-RA) and all-trans-retinoic acid (tretinoin, Retin A, all -trans-RA) arc effective drugs for the treatment of dermatological disorders. Unfortunately, the high teratogenicity of the retinoids is a major drawback to their broad use. A characteristic pattern of congenital cardiac and central nervous system problems was found in human infants who had been exposed to 13-cis-RA during the first trimester (Rosa 1983; Braun et al. 1984; Lammer et al. 1985). This response was elicited by relatively low, clinically therapeutic doses of 0.5 1.5 mg/kg/day. Although 13-cis-RA is a potent human teratogen, it is only marginally teratogenic in the mouse at doses 100 times higher than those used in human therapy (Kochhar et al. 1984). The all-trans-RA isomer of 13-cis- RA is a potent teratogen in all laboratory species tested (Willhite et al. 1989). It has been shown that the low teratogenicity of 13-cis-RA in the mouse corresponds to low embryo concentrations during organogencsis (Creech Kraft et al. 1987). A single oral dose of 100 mg all-trans-RA or 13-cis-RA per kg body weight was administered to mice (NMRI: Han, Zentralinstitut fiir Versuchstierkunde, Hannover, FRG) at two sensitive stages of organogenesis, i.e. day 9 or day 11 of gestation.
Nuclear protein sorting in heterokaryons and homokaryons
Authors: Ringertz Nils R
Published: November 2023

Our interest in nuclear protein sorting began 25 years ago and was triggered by Professor Harris’ report that it was possible to reactivate RNA and DNA synthesis in inactive chick erythrocyte (CE) nuclei by Sendai virus-induced fusion of chicken red cells with human HeLa cells (Harris 1965, 1967). This finding suggested that human tumour cells contain factors capable of activating chick genes and raised a number of interesting questions about the nature of cytoplasmic signals regulating transcription and replication. In collaboration with Professor Harris we carried out a quantitative cytochemical study of chromatin changes during nuclear reactivation in CE x HeLa heterokaryons.
The genetic analysis of human cancer
Authors: Stanbridge Eric J
Published: November 2023

Another possibility is that in every normal cell there is a specific arrangement for inhibiting, which allows the process of division to begin only when the inhibition has been overcome by a special stimulus ... i.e. definite chromosomes which inhibit division.

Cells of tumours with unlimited growth would arise if those inhibiting chromosomes were eliminated.

One must also ... assume the existence of chromosomes which promote division.
Immunological aspects of cutaneous warts
Authors: Davies Huw
Published: November 2023

Much effort is being devoted to understanding the immunobiology of human papillomaviruses. Owing to the overwhelming experimental and epidemiological evidence to implicate the ‘high risk’ HPV types (notably, HPV 16 and 18) in the development of cancer of the cervix, much of this research effort is focused on the high-risk group. The rationale is two-fold. Firstly, the identification of naturally occurring immune responses will have implications in the design of vaccination strategies. Thus, the kinds of responses and the target viral antigens associated with natural immunity may allow us to elicit particular kinds of responses known to have protective value.
Combined in situ hybridization and immunocytochemistry; investigation of viral pathogenesis at the light and electron microscope levels
Authors: Fleming Kenneth A , Morey Adrienne L
Published: November 2023

Simple detection of viral nucleic acid by in situ hybridization (ISH) has been practised for many years (Brahic and Haase 1978). While this is of considerable value in allowing, for example, estimation of the prevalence of various viruses in different diseases (Myerson et al. 1984), it has certain limitations. Not infrequently, it is impossible to identify unequivocably the type and range of cells infected, for example, virus may be present in mononuclear cells in a tissue or organ, but whether these are macrophages, lymphocytes, endothelial cells, etc. can be impossible to determine. Even when viral nucleic acid is present in cells in an epithelium, it may not necessarily be present in an epithelial cell, e.g. it may be in an infiltrating inflammatory cell or Langheran’s cell.
Introduction
Authors: Ligon J David
Published: November 2023

This book is about two of the three most conspicuous aspects of the reproductive biology of birds, sexual selection and mating systems (see Sections 1.3 and 1.4 below); the third is parental care. Ever since Darwin, birds have provided much of the stimulus for study of these topics, and no other taxonomic group is better suited for illustrating patterns and processes of these interrelated phenomena. Although the Class Aves is unusually conservative in production of young, with every species being oviparous, it probably exhibits more diversity in breeding behaviour and sexually-selected ornamentation than any other vertebrate group. This diversity of reproductive strategies has even been compared to that of insects; for example, Wilson (1975) points out that non-breeding helpers of cooperatively breeding bird species are similar to the insect systems classified by entomologists as ‘advanced subsocial,’ and notes that birds also parallel insects in the repeated evolution of social or brood parasitism.
Introduction
Authors: Verrall G H , Collin J E , Pont Adrian C
Published: November 2023

Verrall was born on 7 February 1848, the youngest of seven children in a family whose forbears had lived in the Sussex town of Lewes for hundreds of years. He was educated at Lewes Grammar School, and on leaving in 1864 joined the Civil Service at Somerset House. However, he found neither the life nor the career prospects to his taste, and in about 1866 became private secretary to his eldest brother John Frederick (1836-1877), who was manager of the Lewes races and Clerk of the Course at Croydon. His great-uncle Plumer Verrall (1782-1852) had been a well-known auctioneer of bloodstock, possessing a gold hammer for use when the bidding moved into four figures. During this period, 1866-1874, Verrall lived at The Mulberries, Denmark Hill, S. E. London. In 1875, uncertain as to whether to stay in this business, he moved back to Sussex, to Friar’s Cottage in Lewes, from 1875 to 1877. Upon his brother’s death in 1877, Verrall was appointed as successor in the business, which he pursued with considerable success. In 18 79 he married and settled at Newmarket, centre of the East Anglian racing business, building himself the house called ‘Sussex Lodge’ (now the Convent of St Louis Primary School) (Plate 4). In 1881 he became partner in the firm of Pratt and Co., Race Course Managers and Bankers, and maintained connections with several race-courses as clerk to the course, manager, auctioneer, etc. For example, he was Clerk of the Course at Lewes, Gatwick and Lingfield. Following Lord Rosebery’s maxim that it is the duty of every good citizen to take some active part in public affairs, he involved himself in local matters at all levels.
Taxa described by G. H. Verrall
Authors: Verrall G H , Collin J E , Pont Adrian C
Published: November 2023

ATRICHOPS Verrall, 1909a: 291. Type-species: Atherix crassipes Meigen, 1820, by original designation. ATHERICIDAE.

AGATHOMYIA Verrall, 1901a: 30. Type-species: Callomyia antennata Zetterstedt, 1819, by designation of Coquillett (1910: 504). PLATYPEZIDAE. MELANGYNA Verrall, 1901a: 313. Typespecies: Melanostoma quadrimaculatum Verrall, 1873, by original designation. SYRPHIDAE.PARITAMUS Verrall, 1909a: 679 [also 765 and 778]. Type-species: Asilus geniculatus Meigen, 1820, by monotypy. ASILIDAE.
Turkana in time perspective
Authors: Dyson-Hudson Rada
Published: November 2023

The way of life of pastoral Turkana in the early 1980s was in many ways similar to that of those Turkana whom the first European adventurers encountered in the late 1800s. The arid, hot, and dusty Turkana climate made the region unattractive to Europeans and to Africans from more humid regions; traditional Turkana livestock herding is well suited to the region; Turkana District is far from major cities and administrative centers; and the Turkana people, deeply rooted in their own values and experiences, have always been difficult to control. However, external events during this century are as important as ecological and environmental constraints within Turkana for understanding the ‘backwardness,’ ‘intransigence,’ and ‘resistance to change’ so often attributed to Turkana. In this section, some of the political, historical, and socio-cultural factors are examined which contributed to the isolation of Turkana, and to the mutual hostility between the Turkana and Government, whether Colonial or National. The focus is on southern Turkana, but events in northern Turkana which had a major impact on the south are considered.
Nomadic movements
Authors: Mccabe J Terrence , Dyson-Hudson Rada , Wienpahl Jan
Published: November 2023

The multi-species herds of Ngisonyoka livestock efficiently convert into human food the low and generally patchy plant productivity of Ngisonyoka territory (see Chapter 3). This is achieved with very few inputs such as capital equipment or fossil fuels from outside the boundaries of the South Turkana ecosystem. Movement of livestock is the primary adaptive strategy that Ngisonyoka herd owners use to cope with the low spatial and temporal predictability of plant productivity, and the variability of water resources. Movement is also used to avoid environmental risks. Because the animals are herded by day and corralled by night, movement of livestock also requires movement of the people managing the herds. An acute awareness of the patterns of human and livestock mobility is fundamental to understanding Turkana adaptation. Social consequences of the need to move frequently were discussed in Chapter 4.
Infant, child, and adolescent growth, and adult physical status
Authors: Little Michael A , Gray Sandra J , Pike Ivy L , Mugambi Mutuma
Published: November 2023

Growth, which is a universal property of life, is also a keen indicator of the health and adaptability of children in a given society. In addition, it is an indicator of how well the society itself provides for its dependent children. Our work with child growth, and its culmination, adult status, is central to the studies in biological anthropology. Here we have attempted to define patterns of growth, and to assess how these patterns reflect the biobehavioral status of children in Turkana society. This chapter proceeds by first describing fundamental processes of growth, then moves to a discussion of African pastoral children, followed by a description of the results of the Turkana research, and finally moves to discuss Turkana growth and adult physical status in the context of Turkana society and ecology.
Tree Diseases And Disorders
Authors: Butin Heinz
Published: November 2023

This concise and accurate diagnostic guide to the diseases and disorders that affect both forest and amenity trees in Europe (and some on other continents as well) will be invaluable in many studies, from pest control and forestry to landscape management and plant pathology. The book is organized by specific tree disorders; separate chapters deal with leaf diseases, bark damage, growth abnormalities, and other disorders. Each chapter explores causal agents both external and botanical, the biology and economic significance of these factors, and ideas on prevention and control of disease. Important trees throughout northern Europe are covered, as well as those scheduled for quarantine from outside.
Wilt Diseases
Authors: Butin Heinz
Published: November 2023

Dutch elm disease ranks as one of the most damaging of tree diseases, with many millions of elms having fallen victim to it during this century [32]. The elm populations of Europe, North America, and parts of Asia have been affected by two successive pandemics, the second and more devastating of which has two centres of origin; in the North American and Eurasian continents. A characteristic symptom of the disease is the wilting and discoloration of the leaves during the growing season. The extent of the disease within the crown and its rate of development vary according to the aggressiveness of the form of the fungus that is involved, as well as the genetically and environmentally determined susceptibility of the host.
Damage to Fallen and Felled Timber
Authors: Butin Heinz
Published: November 2023

If a tree is felled, or snaps, it undergoes a series of changes which start with the progressive death of its living tissues and may continue for many years after death. As the tissues lose vitality, their active defence systems collapse, allowing colonization by a characteristic succession of micro-organisms and animals. This succession continues for many years, if the timber is not first utilized by man, and eventually results in the complete breakdown of the tree. Logs generally need to be utilized promptly if their commercial value is not to be seriously reduced.
Vascular-derived growth factors: potential role in the development of the tumour vasculature
Authors: Bobik A , Agrotis A , Little P J
Published: November 2023

There are now strong indications that the growth of many solid tumours is dependent on a high level of vascularization via angiogenesis. Angiogenesis, the formation of new capillaries from pre-existing blood vessels appears also necessary (but alone is not sufficient) for subsequent tumour infiltrations and metastases of a tumour (1-3). In many organs such as the bladder (4), cervix (5), and the breast (6-8) the commencement of angiogenic activity marks the end of the prevascular phase of the developing carcinoma, which may have persisted for years with only evidence of hyperplastic growth. However, once a dense pattern of vascularization is formed, neoplastic growth becomes apparent and tumour size increases rapidly; bleeding may occur from the newly formed capillaries and the risk of metastases increases dramatically (2,3,8,9).
Natural hybridization between Xenopus laevis laevis and X gilli in the south-western Cape Province, South Africa
Authors: Picker M D , Harrison J A , Wallace D
Published: November 2023

Hybridization occurs between the endangered Xenopus gilli and X. laevis laevis in the south-western Cape Province. X. gilli is adapted to the acidic blackwaters that are found in the unique fynbos vegetation biome (Cape Floral Kingdom). Under conditions of disturbance these ponds become accessible to X. laevis, which leads to hybridization. Phenotypically, and on features of the mating call and female release call, natural X. gilli x X. laevis hybrids fall into two distinct groupings which are X. gilli-like or X. laevis-like. The erythrocytic nucleus diameters of hybrids do not implicate a polyploid condition in any of the hybrids examined. This, and the near absence of hybrids that are phenotypically intermediate between the parental species, suggest that hybridization has led to the backcross of F1 individuals with the parental species, without the involvement of polyploidy. The future survival of X. gilli thus appears to be threatened not only by habitat destruction, but also by subtle and extensive introgression with X. laevis genes.
The habitat templet
Authors: Giller Paul S , Malmqvist Björn
Published: November 2023

Like any other habitat, lotic habitats pose animals and plants distinctive adaptive challenges which arc set by the particular and often unique physical, chemical, and biological environment of rivers and streams. To understand how lotic organisms meet these challenges we must first understand the nature of running waters as an environment to live in. Although on the face of it this may seem a reasonably straightforward exercise, things are complicated by the fact that there appears to be a series of interdependent factors that operate in running waters. At the smallest scale, within a pristine stream system, flow patterns, temperature, and substrate seem to be the key physical variables. Oxygen levels are also important to the biota but are largely governed by these three physical factors.
Life in running waters
Authors: Giller Paul S , Malmqvist Björn
Published: November 2023

Running waters harbour a multitude or species ranging in size from viruses and small bacteria to large vertebrates. Small organisms are ubiquitous in running waters but large aquatic animals arc naturally more or less confined to large rivers. A quick glance into a stream might reveal a few fish but little else. However, picking up a stone from the stream bed will provide a glimpse or the thriving life in the stream. Because of the continuous downstream flow of water, few organisms are able to dwell in the water column unless the current is slow. Instead most species are associated, in one way or another, with the substrate. This includes micro- and filamentous algae attached to rocks, higher plants rooted in the substrate, and invertebrates often living in the interstices between mineral particles, on rock faces or in leaf packs.
The evolution of ratites and tina1nous
Authors: Davies S J J F , Bamford Michael J , Loomes Danika
Published: November 2023

What are the ratites and tinamous? Opinions differ, and will probably continue to differ for many years yet. In this book they are taken to comprise the great flightless birds of the world, ostrich, cassowary, emu, kiwi, rhea, their recently extinct relatives, elephant birds and moas, and their small relatives, the tinamous. Following recent opinion (Olson 1985, Anderson 1989, Murray and Mcgirian 1998) the mihirungs (Drornornithidae), giant runners or thunder birds of the Australian fossil record, arc excluded from the ratites.
Feeding ecology
Authors: Davies S J J F , Bamford Michael J , Loomes Danika
Published: November 2023

The foods taken by the various ratites and tinamous are described in the Species accounts. The diets of the large species have much in common, although they differ in detail simply because the birds live in different continents and h:we different foods available to them. The diet is of the parts of plants where nutrients are concentrated, flowers, seeds, fruits and the growing points of young shoots. In addition all species are reported to take some animal food, insects and small vertebrates.
Rheas
Authors: Davies S J J F , Bamford Michael J , Loomes Danika
Published: November 2023

Large flightless birds with long legs and three toes, the hallux being absent. They have no clavicle and the tibia is ,without a bony bridge. There are no tail feathers. The caecae of the alimentary canal are large and the syrinx has only one pair of syringeal muscles. The bill is depressed and broad, with the culmen flattened and cured at the tip, which over-laps the lower mandible. The nostrils are large, oval, and placed in the middle of the bill in a large membranous groove.
The recognition of ancient reefs
Authors: Wood Rachel
Published: November 2023

All reefs form as the direct or indirect result of organic activity that has promoted a higher rate of in-situcarbonate production than in surrounding sediments (Fig. 2.1). Reefs develop only where the rate of carbonate production exceeds any loss due to erosion and transport away from the reef. In the Ancient, this produces massive, often unbedded, accumulations within otherwise normally bedded strata (Figs 2.l(c) and (d)) indicating that the processes operating within the reef differed from those beyond it.
The role of physicochemical change
Authors: Wood Rachel
Published: November 2023

The ambient physicochemical environment and its fluctuations influences reef growth on many scales: from local hourly, daily, or seasonal effects which control the functioning of individual reef organisms; to regional factors that determine the distribution of different reef types; to those slow, but sustained and widespread changes which operate over millennia to millions of years that are responsible for Earth’s changing climate, continental and ocean distribution, and ultimately for the geological record of reef-building.
Chain Compounds and One-Dimensional Physical Behaviour
Authors: Day P
Published: November 2023

There are three reasons for devoting a chapter to solids containing chains of closely spaced atoms, ions or molecules. Firstly, there are numerous physical phenomena quite specific to lattices having interactions between repeating units in one dimension alone. Secondly, because the topology of a chain is so simple, chemical correlations between structure and properties are more easily arrived at. Finally, the structural principles themselves are more easily discernible when coordinated polyhedra are only joined along a single axis.
Metal-Rich Compounds
Authors: Simon Arndt
Published: November 2023

There are two main reasons why solid state chemistry presents difficulties for many chemists. One is the quasi-infinity which we meet in a crystal. Instead of having simple small molecules containing only a few atoms, large units which contain approximately Avogadro's number of atoms have to be surveyed. Fortunately, symmetry allows us to cut these large units into smaller pieces and to deal only with a representative part. There are many different ways of cutting down crystal structures. In this chapter one special way will be chosen which tries to link molecular and solid state chemistry. The second problem in understanding solid state compounds arises from the frequent occurrence of unusual compositions. Forgetting about the residual non-stoichiometry which is inherent to the solid state, even idealized compositions like Hf3P2 or Ni3S2 seem difficult to understand on the basis of a conventional valence concept with integral oxidation numbers. The difficulty in accepting such compositions as nothing unusual is rather surprising. No chemist is puzzled by a composition C3O2.
The free-electron picture
Authors: Altmann Simon L
Published: November 2023

We shall be concerned in this chapter with a simple model of solid materials which is particularly adapted for the description of metallic crystals. The discussion of this picture, however, will serve as an introduction to some of the ideas of the band formalism which will be developed in later chapters and which will also allow us to describe covalent crystals, such as silicon.
Catalytic applications of cyclophanes
Authors: Murakami Yukito , Kikuchi Jun-ichi , Hisaeda Yoshio
Published: November 2023

Enzymes are ingeniously designed natural catalysts that demonstrate specific substrate recognition, marked rate enhancement, and appropriate selection of reaction pathways. Such catalytic features are generated essentially due to the formation of a specific enzyme-substrate complex as the key intermediate. Thus, various types of artificial molecules or molecular assemblies that exhibit guest-inclusion capability have been developed as enzyme mimics; e.g. cyclodextrins, cyclophanes, crown ethers, synthetic polymers, micelles, and bilayer membranes.
The transition metal cyclidenes: a broad family of complexes well suited to inclusion chemistry
Authors: Busch Daryle H , Stephenson Neil A
Published: November 2023

Living systems perform a variety of chemical transformations which are without precedent in the laboratory under similar conditions, and specific examples continue to inspire new areas of chemical research. Many of the natural systems incorporate a transition metal ion but the function of that metal ion is strongly dependent on its protein environment. Thus, haeme proteins perform a variety of functions including oxygen transport and storage, electron transport, and oxygen activation3 although the active site is an iron porphyrin in each case. The role of the protein has been examined in detail for the dioxygen transport and storage proteins haemoglobin and myoglobin. For example, neutron diffraction studies have indicated that oxygenated myoglobin contains a hydrogen bond to bound dioxygen, and the influence of tertiary effectors on the oxygenation of the haemoglobin tetramer reflects conformational changes of the protein.1 Models of myoglobin behaviour have been developed from superstructured porphyrins.
Polymorphism and the investigation of structure-property relations in organic solids
Authors: Bernstein Joel
Published: November 2023

It is axiomatic that structure plays an important role in determining the properties of materials. Understanding that role is crucial in our efforts to design materials with predetermined properties. In seeking to understand the relationship between structure and properties we attempt to design experiments which will allow us to eliminate as many variables as possible and to focus strictly on the structural variations and their manifestations in the variation of chemical and/or physical properties. The existence of polymorphic forms provides a unique opportunity for the investigation of structure-property relationships, since the only variable between two polymorphic crystal forms is that of structure. In such cases variations in properties must be due to differences in structure. and the analysis and interpretation of these experiments is considerably facilitated by the limited number of variables.
The relation between S→O hypervalent bonds and S … 0 close contacts in crystal structures of sulfuranes, analogous sulfonium salts, and related compounds containing X→S … 0 (X=S, Cl, 0, N, C) moieties
Authors: Kálmán A
Published: November 2023

Following the X-ray analysis of a dichlorosulfurane (Baenziger et al, 1969) and the fundamental work of Musher* (1969) which predicted the existence of the first stable diaryldiacyloxyspirosulfurane (I), synthesized and structurally described two years later by Kapovits and Kalman (1971), considerable work has been done on the structures (and chemistry) of various kinds of tetracoordinate tetravalent sulfur species.
The recording and analysis of data from macromolecular crystals
Authors: Helliwell J R
Published: November 2023

This paper surveys various aspects of the recording and analysis of macromolecular crystal data. The emphasis given is to highlight common principles and methods of the variety of techniques. Analyses of data collected via monochromatic/rotating crystal and white beam/stationary crystal (Laue) methods are discussed. Aspects of area detector data collection using various apparatus (MWPC, TV and image plate/storage phosphor) are dealt with.
Crystals
Authors: Watkin D J
Published: November 2023

The overall nature of the CRYSTALS program has been described previously (Crystallographic Computing 3 and Crystallographic Computing 4) While the general structure of the program remains unchanged from those earlier reports, the details and facilities available have evolved in response to our own needs and the requests of the network of users. Rather than repeat the information to be found else where, this article will be concerned with some actual applications of the program.
Dealing with imperfect isomorphism in multiple isomorphous replacement
Authors: Read R J
Published: November 2023

Multiple isomorphous replacement (MIR) is the major technique for obtaining the phase information necessary to solve new protein crystal structures. The optimal use of information from MIR experiments requires a good understanding of the sources of error, and of how they propagate into the phases. The chief sources of error are errors in the measurements, imperfect isomorphism, and errors in the heavy atom model. Their effects are examined, and an improved treatment for non-isomorphism is proposed. In addition, a method to combine properly the information from several derivatives is reviewed. Tests using calculated data with simulated errors give results consistent with the probability distributions. The familiar phase problem of crystal structure determination arises because the diffraction experiment measures only the intensity (or amplitude) of the structure factor, but not its phase. In order to reconstruct the electron density in the crystal, by taking the Fourier transform of the structure factors, we need estimates of the phases. Multiple isomorphous replacement (MIR) is still the major technique used to obtain this phase information for new protein structures.
Phasing by anomalous scattering: theoretical aspects
Authors: Karle J
Published: November 2023

In recent years, there have been a number of theoretical developments concerning the application of the anomalous dispersion technique for the determination of structure, particularly that of macromolecules. A strong motivation for this work has been the desire to develop mathematical relationships that can readily take full advantage of the information that is available from anomalous dispersion experiments. Some of the developments have already begun to facilitate the practical aspects of phase determination for macromolecular structures (Karie, 1989c). Their utility has been enhanced by the use of the high intensity, tunable radiation that is available from synchrotron sources. A further enhancement may be anticipated with the application of recombinant DNA techniques to the tailoring of protein derivatives (Hendrickson, 1987).
Molecular replacement
Authors: Fitzgerald P M D
Published: November 2023

This paper will discuss the theory, implementation, and limitations of the computations used in phasing crystal structures using the molecular replacement method. It will describe the rotation function, the various positioning techniques (translation function, correlation searches, and packing analysis), and the methods used to improve upon a molecular replacement solution prior to refinement Means for evaluating the correctness of a solution will be discussed and some illustrative examples of structures phased by molecular replacement will be given. Finally, some recent work in developing a methodology for using the rotation function to find erroneous regions in a molecular replacement probe structure will be presented.
Introduction to macromolecular refinement
Authors: Sussman J
Published: November 2023

‘Three-dimensional macromolecular models based on X-ray diffraction data are derived initially from electron density maps. The atomic coordinates based on such models are not very accurate, in part because the maps are of insufficient resolution to show the constituent atoms individually and in part because the phases used to calculate the electron densities are not very accurate. Even for models derived from the best electron density maps, the accuracy of the atomic coordinates is likely to be no better than about 0.5 Å, and localized regions of models derived from average quality maps may suffer more serious errors. Such models, however, are very useful in showing the overall features of macromolecules and the pattern of chain folding but to understand much of the chemistry of these molecules and how they function requires more accurate parameters. It is important, therefore, to improve the models of macromolecules by refining them to the fullest extent possible.’
Time-averaged crystallographically restrained molecular dynamics
Authors: Gros P
Published: November 2023

A number of reports have appeared in the literature to account for mobility and disorder in macromolecular crystals. Schomaker & Trueblood (1968) showed that, to a first approximation, the atomic temperature factors can be related to the overall mobility of the molecule. It is, therefore, possible to refine the six overall anisotropic B-factors of the whole molecule (Sheriff & Hendrickson, 1987). More atomic detail is taken into account in the restraints on individual temperature factors of neighbouring atoms (Hendrickson & Konnert, 1980). This procedure is based on the riding-motion model of Busing & Levy (1964). Furthermore, Konnert & Hendrickson (1980) propose a procedure to refine atomic anisotropic temperature factors based on the stereochemistry of the model. Yu et al. (1985) show that the assumption underlying this method, i.e. a simplified correlation between the stereochemistry of the model and the atomic fluctuations, is invalid. Another approach is described by Haneef et al. (1985). Segments, like ring systems of Phe and Tyr, are treated as rigid groups, of which B-factors are refined anisotropically (Howlin et al., 1989 ). Very recently Kidera & Go (1990) have proposed an elegant method that treats the anisotropy of the atomic distributions of the molecule in the crystal by a normal mode refinement. In all these procedures the anisotropy is treated in a restricted way to reduce the number of parameters, and no general treatment is given for anharmonicity.
Applications of silicon and tin in borane chemistry
Authors: Brown* Herbert C , Rangaishenvi Milind V
Published: November 2023

In 1956 it was discovered that the simplest hydrogen compound of boron, B H, diborane, adds with remarkable ease to unsaturated organic compounds. The products are organoboranes. Investigation of these organoboranes revealed that they have a rich chemistry, greatly facilitating the synthesis of a vast host of organic compounds. The substitution reactions of organoboranes reveal a unique feature. They proceed with complete retention of structure and configuration.
Silicate materials in new technology
Authors: Fuxi Gan
Published: November 2023

A review is given of the application of silicate materials in optics and optoelectronics. The coverage includes the development of silicate laser and optical materials (such as glasses and crystals), and the applications of rare-earth compounds and minerals in advanced glasses and ceramics.
Organotin halides as catalytic precursors in dehydration processes.:I.Acetalizations and transacetalizationsof alicyclic diols and polyols
Authors: Marton Daniele , Slaviero Pierangelo , Tagliavin Giuseppe , Vanzan, Nicoletta , Zordan Michele
Published: November 2023

Butyltin trichloride can be used with advantage as a catalyst for the preparation of cyclic acctals from aldehydes and diols, or polyols under mild conditions and with short reaction times. Many 1,3-dioxolanes and-dioxanes can be prepared via acetalization and transacetalization processes. The initial stages of the reaction involve either (i) activation of the aldehyde via formation of RCHO-SnBuCJ, followed by its interaction with the diol, or (ii) formation of the organo-alkoxytin dichloride HO― (CH),, ―O―SnBuCl (n = 2,3), which is followed by the insertion of the aldehyde into the Sn―O bond.
How silicon and tin meet in polymer and organic synthesis
Authors: Gauron V , Jousseaume B , Verlhac, M Pereyre J -B , Frances J -M
Published: November 2023

The organic chemistry of silicon and tin has gained much significance in recent years on both academic and industrial grounds. At Bordeaux, we have been involved in research where both silicon and tin have featured synergistically. Two examples are presented in this paper. The first topic deals with polymer science and describes the preparation and the applications of new latent organotin catalysts for the reticulation of polyorganosiloxane chains (SiOH/SiOR and SiOH/SiH polycondensations). The underlying principle is to use bis(2-acyloxyalkyl)diorganotins, which are themselves not catalysts, but which are thermally degraded through a J3-elimination process into diorganotin dicarboxylates, an important class of commercial catalysts.
Organotin xanthylacetates: 119mSn Mossbauer and in vitro fungitoxicity study
Authors: Weng Ng Seik , Kuthubutheen A J , Arifin, Zainudin , Das V G Kumar
Published: November 2023

In studies on the biological properties of triorganotin compounds, it has been widely held that toxicity is dominantly governed by the nature of the three C-bonded organic groups on tin, with only marginal influence being ascribed to the anionic group through properties such as solubility and volatility. However, recent studies on triaryltin systems possessing a wider selection of anionic groups have indicated that rather significant influences on overall toxicity can be exerted by the noncarbon-bound residues.
Microwave plasma chemical vapour deposition: a model for the production of thin carbon films, with possible extension to silicon
Authors: Barmawi Khairurrijal M
Published: November 2023

A simple plasma CVD reactor has been built using a 500 W, 2.45 GHz microwave oven as a plasma generator. The reactor has been used to deposit carbon from liquid natural gas onto glass plates. The rate of deposition is 34 As-1 and films typically of 6 |xm thickness can be conveniently obtained. The carbon films have been analysed by FT-IR spectroscopy and found to contain sp, sp2, and sp3 hybridized carbon fragments; there are also indications of the presence of C=O and C=S groups. The reactor offers much scope for similar studies on thin silicon films.
Communication in the physical sciences
Authors: Laidler Keith J
Published: November 2023

Progress in the sciences is closely linked to the manner in which scientists communicate with each other and with the general public. Over the years there have been important changes in the extent to which different kinds of communication have been used. In earlier times scientists tended to be secretive about their work, but were faced with the dilemma of not being able to claim priority for a discovery if anyone else announced it later. Newton was involved in a number of difficulties of this kind, and often became engaged in acrimonious controversy. One way around the dilemma was to summarize a discovery in the form of an anagram so complicated that it could only be deciphered by the author himself. In its early days the Royal Society was a repository for anagrams. Much of the communication of early science was in the form of personal letters. Robert Boyle, for example, described many of his experiments in the form of letters to friends and relatives, often publishing them later as pamphlets. He also communicated many of his findings orally to the numerous visitors to his laboratories in Oxford and London. Even later the same kind of informal communication was still used to some extent. In the nineteenth century Maxwell, Kelvin and P. G. Tait were frequent correspondents on matters relating to thermodynamics and the kinetic theory. Very little of Max¬ well’s important work on thermodynamics, including his ‘Maxwell demon’, was published in a formal way, and our knowledge of much of it has come to us indirectly from the many private letters (and often postcards!) he wrote, and from his university lectures.