bluuebunny/crossref_metadata_2025 huggingface dataset:
Local expression of insulin-like growth factors during tissue growth and regeneration
Authors: Jennische Eva , Isgaard, J ö rgen , Isaksson Olle G P
Published: November 2023

Although somatomedins (now more commonly known as insulin-like growth factors, IGFs) were initially considered to be derived from the liver, both their expression and local production have since been demonstrated in numerous organs and tissues of many animal species. The functions of locally produced IGFs are largely unknown but are beginning to be clarified. This chapter will mainly focus on recent studies and their relevance to possible in vivo effects during growth and regeneration.
Lamina anatomy
Authors: Tomlinson P B
Published: November 2023

The anatomy of the lamina (leaflets and leaf segments) of palms has been studied extensively because of the relative accessibility of the organs (herbarium specimens can be used, Fig. 10.1 ), the wide range of structure shown, which is often diagnostic, and the frequent commercial significance of the information (Plate 10). Much less information has been obtained about the biological significance of leaf structure and variation in relation to ecological conditions (but cf Koop 1907) even though quite superficial observations will show that palms from contrasted habitats, e.g, moist, shady versus dry, open, have contrasted leaf anatomy. Studies with a primarily systematic orientation include those of Achilli (1913), Bargagli-Petrucci (1900), Bobisut (1904), Eberwein (1903), Glassman (1972), Lecomte (1916), Licopoli (1881), Machado (1945), Pfister (1892)
Fossil amphibians and reptiles and the Africa–South America connection
Authors: Buffetaut Eric , Rage Jean-Claude
Published: November 2023

Although it was the subject of much controversy among geologists and palaeontologists until well into the 1960s, the former existence of a land connection between Africa and South America no longer needs to be demonstrated. Within the general framework of plate tectonics and continental drift, it is now clear that Africa and South America were once part of the southern super-continent Gondwana, itself a constituent of Pangaea during the Late Palaeozoic and the Early Mesozoic. The distribution of some fossil amphibians and reptiles was one of the important palaeobiogeographical arguments in favour of such reconstructions. The occurrence of very closely related representatives of a group of small early reptiles, the mesosaurs, in the Permian of South America and South Africa, for instance, was used as evidence of a connection between Africa and South America in the Late Palaeozoic, well before continental drift became generally accepted. The Late Triassic dinosaur faunas of South Africa and South America also exhibit resemblances—which is not surprising in a palaeo-biogegraphical situation of global faunal similarity, due to the existence of Pangaea. Although it may seem paradoxical, the Africa-South America connection becomes an interesting scientific problem mainly when it ceases to exist, when the opening of the proto-Atlantic Ocean sometime in the Cretaceous separates the two continents from each other and makes faunal interchange increasingly difficult. A comparative history of amphibians and reptiles in South America and Africa, through the Cretaceous and into the Tertiary, reveals similarities and divergences suggesting a pattern of faunal exchanges in which vicariant evolution and dispersal across barriers both played a part.
Prey size selection and intake rate
Authors: Zwarts Leo , Cayford John T , Hulscher Jan B , Kersten Marcel , Meire Patrick M , Triplet Patrick
Published: November 2023

Do predators take all the individual prey belonging to one species that they encounter, and if not, to what degree are some prey under-represented in the diet and why? These questions are important in every study of the interaction between predators and their food supply. This chapter first analyses the degree to which the selection of prey sizes within one prey species by Oystercatchers can be understood as a passive process in which a randomly searching bird takes all the prey it encounters; this will be referred to as ‘passive size selection’. As we shall see, however, Oystercatchcrs reject certain size classes of prey which they actually encounter, and hence there is also ‘an active size selection’, The rules that Oystercatchers obey when selecting size classes actively, and whether these can be derived from optimal foraging models, are then discussed.
How Oystercatchers survive the winter
Authors: Goss-Custard John D , Durell Sarah E A le V dit , Goater Cameron P , Hulscher Jan B , Lambeck Rob H D , Meininger Peter L , Urfi Jamil
Published: November 2023

Over the last 25 years, much emphasis has been placed by ornithologists on the hypothesis that, in many temperate-zone birds, food shortage is an important cause of death outside the breeding season (Lack 1954; Newton 1980). This idea has underpinned most of the research carried out on Oystercatchers on their migration and wintering grounds. It is one reason why, in the preceding five chapters of this book, Oystercatchers have been expected to make the choices while foraging that increase the rate at which they obtain energy and/or nutrients (Hulscher, Chapter 1; Zwarts et al., Chapter 2; Sutherland et al., Chapter 3; Ens and Cayford, Chapter 4; Goss-Custard et al., Chapter 5). It is also the reason why so much concern is expressed by conservationists when winter feeding areas are threatened by the many human activities that take place on the foreshore (Lambeck et al., Chapter 11, this volume).
Historical overview of classification and phylogeny of the Proboscidea
Authors: Tassy Pascal , Shoshani Jeheskel
Published: November 2023

Extant elephants were first named Proboscidea by Illiger in 1811. At that time, they were known as ‘pachyderms’. According to Cuvier’s Le regne animal (1817), the pachyderms also included tapirs, pigs, hippos, and hyra:xes. In 1834, Blainville clustered elephants and sirenians together in the ‘gravigrades’, a mono-phyletic group which was named Tethytheria by McKenna in 1975 (which includes the orders Proboscidea, Sirenia, and Desmostylia).
Ontogenetic evidence for incisor homologies in proboscideans
Authors: luckett W Patrick
Published: November 2023

Living elephants are characterized by the presence of greatly elongated, ever-growing tusks in the upper jaws; these modified incisors may attain a length of up to 345 cm (11. 5 ft) in male Loxodonta africana (Sikes 1971). Following Andrews’ (1906) comparison of 1e large tusks of Miocene through Recent proboscideans with the moderately enlarged second incisors (12) in both jaws of the Eocene genus Moeritherium, most authors have accepted his proposed homologies of the tusks as specialized I2 in all fossil and extant proboscideans (e.g. Matsumoto 1923; Osborn 1936; Sikes 1971). The occurrence of hypertrophied 12 as a shared, derived attribute for all proboscideans was adopted recently by Mahboubi et al. (1986) in their analysis of the affinities of the Eocene genus Numidotherium from Algeria. Most authors have also considered the small, transitory incisor that occurs during the fetal and early postnatal period in extant elephants to be the deciduous predecessor (dI)of the permanent tusks in the upper jaw (Corse 1799; Rose 1894; Schaub 1948; Sikes 1971).
Growth and sexual dimorphism among Miocene elephantoids: the example of Gomphotherium angustidens
Authors: Tassy Pascal
Published: November 2023

It has long been known that elephants are ever-growing mammals. The lifespan of the African elephant. Loxodonta africana, is estimated at about 60 years and growth lasts until the last molar comes into wear, i.e. 40–50 years, although the rate of growth is slowed after 40 years in males and around 30 years in females (Laws et al. 1975; Hanks 1979). Daubenton, in 1764, first understood that the molars of the elephant succeeded during life without vertical replacement. Identification of grinding teeth and their state of wear was then used to give an individual age to living elephants. Current dental ages are those proposed by Laws (1966) and modified by Sikes (1971), Hanks (1972), and Beden (1979) for Loxodonta africana; and by Roth and Shoshani (1988) for Elephas maximus. Such an approach was rarely applied to fossil proboscideans, due to scarcity of material. One notable exception is found in Saunders (19 77) who defined five age-groups for the American mastodon, Mammut americanum.
Sexual dimorphism in the mammoth skull, teeth, and long bones
Authors: Averianov Alexander O
Published: November 2023

Sex determination in mammals is important for understanding their ecology and population biology. In large mammals, sexual dimorphism is expressed by the fact that males are bigger than females and have strongly developed secondary sex features, such as horns, or enlarged canines or incisors. In recent African elephants, Loxodonta africana (Blumenbach 1797), the males are taller than females, (males may reach 4.0 m in height, as distinguished from females that range from 2.0 to 3.0 m). Tusks of males are also thicker and longer that those of females (Sikes 1971). Direct sex determination in extinct animals is possible only in exceptionally rare cases, as in frozen carcasses of Pleistocene mammals with preserved genitalia. The sexes of three individual woolly mammoths, Mammuthus primigenius (Blumenbach 1799), all males, were determined in this manner. They are: the Adams’ mammoth (1799; Fig. 26.la, b), the Berezovka mammoth (1901; Fig. 26.2a, b), and the Magadanian mammoth calf (1977; Fig. 26.3). The sex of the Adams’ mammoth (ZINN 71911; Fig. 26.la, b), discovered in 1797 by a Tungusian hunter, Osip Schumachov, and a merchant, Roman Boltunov, (Tilesius 1815), was easily determined because the carcass contained preserved identifiable tissues and organs. The penis of the Berezovka mammoth (ZINN 77340; Fig. 26.2a, b) can be observed on the mounted specimen at the Zoological Museum in St. Petersburg. On the other hand, the penis of ‘Dima’ (ZIN N 70188; Fig. 26.3) was separated from the carcass (fig. 18 of Vereshchagin 1981).
Distribution and palaeoecology of central and western North American Mammuthus
Authors: Agenbroad Larry D , Mead Jim I
Published: November 2023

North American mammoths not only endured varied climatic conditions during the Pleistocene, they radiated biologically and geographically. The early Irvingtonian species Mammuthus meridionalis (Nesti, 1825) was followed by M. imperator (Leidy, 1858) in the late Irvingtonian, and succeeded by M. columbi (Falconer, 1857), M. primigenius Blumenbach, 1803, and M. exilis (Stock and Furlong, 1928) in the Rancholabrean (following Maglio 1973; Agenbroad and Barton 1991). These latter species were contemporary but adapted to different habitats, with their distribution covering most of the North American continent. Highly mobile and migratory, adapted to grasslands (which were expanding) or steppe-tundra (which was diminishing), it seems highly unlikely that habitat mosaic change alone could cause extinction of the genus at the end of the Pleistocene.
The Hawaiian Honeycreepers
Authors: Pratt H Douglas , Jeffrey Jack , Conant Sheila
Published: November 2023

The Hawaiian Honeycreepers are typified by nectar feeding, their bright colouration, and canary-like songs. They are considered one of the finest examples of adaptive radiation, even more diverse than Darwin's Galapagos finches, as a wide array of different species has evolved in all the different niches provided by the Hawaiian archipelago. The book will therefore be of interest to evolutionary biologists and ecologists, as well as professional ornithologists and amateur bird watchers. As with the other books in the Bird Family of the World series, the work is divided into two main sections. Part I is an overview of the Hawaiian Honeycreeper evolution and natural history and Part II comprises accounts of each species. The author has produced his own outstanding illustrations of these birds to accompany his text.
The Hawaiian honeycreepers: evolutionary triumph and ecological tragedy
Authors: Pratt H Douglas , Jeffrey Jack , Conant Sheila
Published: November 2023

The most important defining fact for Hawaiian honeycreepers is that they are endemic to the Hawaiian Islands in the tropical N. Pacific Ocean. This, the most isolated of the world’s archipelagoes, with relatively large and ecologically diverse islands (Chapter 2), provided a superb natural laboratory. Although Darwin’s famous finches of the Galápagos are better known and arguably better studied, even students of that group agree that the Hawaiian honeycreepers are the most spectacular and most extreme avian example of adaptive radiation on islands (illustrated diagrammatically in Plate 8).
Discovery and research: historical perspectives
Authors: Pratt H Douglas , Jeffrey Jack , Conant Sheila
Published: November 2023

The century of discovery Cook and other British explorers When naturalists with Captain James Cook’s third voyage came ashore at Waimea, Kaua‘i in January 1778, they bartered with local villagers for a bundle of bright red birds.We now know that they were ‘I‘iwi, the first Hawaiian honeycreeper to be seen by scientists or non-Hawaiians. Later, Cook spent more time at Kealakekua Bay on the Kona Coast of Hawai‘i, where he collected more ‘I‘iwi along with specimens of Lesser ‘Akialoa, Hawai‘i Mamo,‘Apapane, Hawai‘i ‘Amakihi, ‘Akepa, and ‘O‘u (Stresemann 1950; Medway 1981; Olson 1989b). These birds were taken back to Europe and described and named, but little was known about them. Over the ensuing century, other species were described by various authors based on specimens similarly collected during brief visits or by island residents who gathered little information about the birds. Relatively few large expeditions visited the islands, and new species came to light willy-nilly.The following is a brief overview of discovery and description of honeycreeper species. For more detailed accounts, see Newton (in Wilson and Evans 1890–99: xi– xix), Kay (1972a), and Olson and James (1994a).
Origin and evolution
Authors: Pratt H Douglas , Jeffrey Jack , Conant Sheila
Published: November 2023

When the various Hawaiian honeycreepers were first discovered, the idea that they could all belong to a single interrelated group must have seemed preposterous. They were birds that ran the gamut of passerine variation, and most of them did not have any obvious close mainland relatives. By the end of the nineteenth century, a consensus had formed that the thin-billed forms were an endemic Hawaiian family, Drepanididae, but most authorities still considered the finchlike species to be just island representatives of the Fringillidae, which at the time included virtually all the world’s ‘finches’ that today are allocated among several families.
Status, conservation, and the future
Authors: Pratt H Douglas , Jeffrey Jack , Conant Sheila
Published: November 2023

When I first visited Hawai’i in 1974, I was opti-mistic about the Hawaiian honeycreepers. After all, even though many were very rare, several had been rediscovered in the previous decade, and a new one had just been found on the windward slope of Haleakala. Surely, it seemed, more suppos-edly extinct species still clung to existence in some remote forest refuge where no one had looked for many years. I was naive enough to think that those that had lasted until ‘enlightened’ modern times would get the help they needed and survive. I never expected to study birds that would be extinct in my lifetime.
Toucans, Barbets and Honeyguides
Authors: Short Lester L , Horne Jennifer F M , Gilbert Albert Earl
Published: November 2023

This book covers in unmatched detail the life history, relationships, biology, and conservation of all the world's toucans, barbets, and honeyguides. These number 133 species, found in tropical regions around the world. The toucans are especially well-known because of their dramatic bills and their association with the Amazon rainforest. The authors have been working with these birds for over 20 years, and their knowledge and expertise in these groups is unrivalled. Much of the information in this book has never previously been published. The colour plates, painted by well-known US artist Albert Earl Gilbert, are probably the best paintings of these birds ever produced.
Forest ecology and genetics
Authors: Matthews John D
Published: November 2023

A forest ecosystem is the product of the climate, geology, terrain and soil, and of the trees, shrubs, animals, fungi, and other organisms living and interacting together on the site. The canopy of leaves and branches supported by the tree stems intercepts incoming radiation and precipitation in the form of rain, snow, or mist. Some radiation is reflected back to the atmosphere and some precipitation is evaporated from the surface of the crowns but the larger proportion of these enter the forest ecosystem together with nutrients borne by rain, dust, and aerosols. The canopy also affects the flow of air over and through the upper parts of the forest, making it turbulent.
Shelterwood systems
Authors: Matthews John D
Published: November 2023

Shelterwood systems are those high forest systems in which the young crop is established under the overhead or side shelter of the old one; at the same time the old crop protects the site. The term ‘shelterwood systems’ includes systems of successive regeneration fellings together with the selection system. In general though not universally, the shelterwood systems aim at natural regeneration whereas the clear cutting system, usually though not invariably, must rely on artificial regeneration. Under the clear cutting system, using natural regeneration, the area to be regenerated is cleared in a single felling and restocked in one season. However, this is possible only where conditions are unusually favourable for natural regeneration, and where it is not necessary to retain any part of the old crop to protect the young one against frost, drought, or other dangers.
Cambrian
Authors: Jialu Yang
Published: November 2023

The inaccuracy of palaeomagnetic data for the Cambrian period, which is dated about half a billion years ago, means that the knowledge of palaeo biogeography, palaeoclimatology, and geotectonics must be applied to its plate reconstruction. Scientists (Zoninshain et al. 1977; Ziegler et al. 1979; Scotese et al. 1979, 1990; Palmer 1981; Lin Jinlu et al. 1985) consider that most Cambrian plates were located in low latitudes and only a few of them may have reached middle latitudes. All the continents, except Gondwana, were small and scattered, although further studies may substantiate the further dismembering of an originally integral plate or reintegration of plates. Figure 3.1 shows the palaeobiogeographical provincialization of the world, using the base map of reconstruction of Franconian age (Late Can1brian) compiled by Scotese et al. (1979, 1990) plus the following modifications on the location of some plates:
Ordovician
Authors: Zhiming Li
Published: November 2023

A number of new marine invertebrate faunas came into being in Ordovician times, and the generally rather monotonous features of the Cambrian biota were changed. Among the fauna were trilobites, graptolites, articulate brachiopods, nautiloids, and rugose and tabulate corals, which are of great significance in stratigraphical correlation and subdivision, biofacies analysis, and palaeobiogeographical provincialization. Many scholars, such as Whittington and Hughes (1972), Jaanusson (1973), Berry (1974, 1979), Lu Yanhao et al. (1976), Chen Junyuan (1980), Sweet and Bergstrom (1984), Cocks and Fortey (1988, 1990), Bergstrom (1990), and Finney and Chen (1990), have studied Ordovician palaeobiogeographical provincialization based on the groups of organisms that they specialized in.
The brown trout: a successful polytypic species
Authors: Elliott J M
Published: November 2023

After reviewing briefly the taxonomy of the family Salmonidae, a summary is provided of past problems in naming brown trout. Next the geographical distribution of brown trout is summarized, first the native distribution and then the world distribution of this successful fish. Finally the life cycle is examined. A brief review shows that large variations in the life cycle are common for many species in the family Salmonidae. This is followed by a more detailed review of life-cycle variation in brown trout. The overall conclusion from the work described in this chapter is that the brown trout is a highly successful, global species exhibiting a range of quantitatively complex life cycles.
Burrows and burrowing animals: an overview
Authors: Meadows Azra
Published: November 2023

A wide range of animals, including man, are known to burrow in terrestrial and aquatic environments, and burrows have been recorded well back in the fossil record. Burrow size and shape is a characteristic of each species. The size of burrows can range from a few millimetres to many metres in length. Burrows may be either simple or complex, may run vertically or horizontally in sedimentary strata, and sometimes may have many branches and chambers. Animal burrows have a number of functions. They can be built for protection from extreme environmental conditions or for defence from predators. Some species dig burrows for foraging or use them as a food store. Others use them as a site for reproductive activities and later as a nursery for young or larval stages. Occasionally a burrow is shared by two species, or an abandoned burrow may be recolonized by another species. All these activities have significant impacts on the environment, such as increased soil fertility caused by soil mixing, changes in the structure of plant communities, increased exchange of chemicals across the sediment-water interface, enhanced microbial activity and alterations in soil and sediment stability and erosion.
Effects of two infauna! polychaetes on sediment shear strength and permeability: an experimental approach
Authors: Meadows Peter S , Hariri M S B
Published: November 2023

Organisms living m the top metre or so of sediments can have major effects on the physical and chemical properties of sediments caused by bioturbation (burrow construction and maintenance), feeding processes and movement within the sediment (Dillon & Zimmerman 1970; Rhoads 1974; Berner 1980; Lee & Swartz 1980; Meadows 1986; Meadows & Tufail 1986).
Introduction
Authors: Brodsky Andrei K
Published: November 2023

Insects were the first organisms in the life of the Earth to rise into the air. The existence of wings made insects faster and more manoeuvrable, enabled them to migrate regularly, and greatly complicated their behaviour. Nutritional and reproductive possibilities grew, and new ways of escaping from enemies appeared.
Ceylon
Authors: Desmond Ray
Published: November 2023

Hugging the southern tip of the Indian subcontinent is Sri Lanka or Ceylon. The Ancient Greek geographers knew the island as Taprobane, hence the botanical specific epithet Taprobanicus. Strategically situated on the principal sea route between East and West, it was a meeting place, an international market, for merchants from Africa and Arabia, the Malay Archipelago, and China. One of its best-known landmarks, Adam’s Peak, was revered by Muslims as the spot where Adam took his last look at the Garden of Eden; Chinese monks made pilgrimages to the island to worship Buddhist relics; Victorian settlers, enchanted by its lush vegetation and equable climate, christened it the Pearl of the Indian Ocean. Europe first learned of the existence of the island through officers in Alexander’s army. Megasthenes at the Maurya court in the Fourth century BC was told that Taprobane ‘has palm-groves where the trees are planted with wonderful regularity all in a row, in the way we see the keepers of pleasure-parks plant out shady trees in the choicest spots’. Classical authorities gave contradictory dimensions for the island which covers about 25 000 square miles; it is not as large, in fact, as Ireland. They believed it to be the largest island in the known world; both Ptolemy and Pliny had it stretching into the southern hemisphere. Even as late as the sixth century the Alexandrian monk, Cosmas, calculated its length to be 900 miles (it is, in fact, 290 miles at its longest). Ibn Batuta (1304--c.1378), perhaps the greatest of all medieval travellers, covered some 75000 miles during 30 years wandering through Asia and Africa, visiting every Muslim state. His pilgrimage, punctuated by frequent marriages and desertions, brought him to Ceylon in 1344. As a devout Muslim, he climbed Adam’s Peak to pray at the blessed footprint of Adam. On his ascent he admired ‘flowers of various colours, with the red rose, about the size of the palm of the hand, upon the leaves of which they think they can read the name of God and of his prophet’. This has been identified as Rhododendron arboreum subsp. nilagiricum and must be the earliest mention of any rhododendron in South Asia although it was not until 1817 that a John Davy recognized it as being a member of that genus.
A Century Of Change
Authors: Desmond Ray
Published: November 2023

If an amateur can be defined as one whose interests and pursuits are the products of self-education indulged in as a pastime then many of the naturalists in India qualified for that epithet. The introductory remarks to the first volume of Asiatick Researches (1788) reminded its readers that.
The Search For Useful Plants
Authors: Desmond Ray
Published: November 2023

In a memorandum on the resources of British India submitted to the Government of India in 1894, George Watt, its leading economic botanist, postulates that in so far as cultivated plants are concerned, India had ‘borrowed far more than she has given’. Critics who not infrequently accuse European powers, and Britain in particular, of exploiting India’s natural resources tend to overlook or to minimize their contributions to the country’s prosperity. The introduction of plants of commercial value has diversified its economy and changed the eating habits of the nation. Indeed all countries have benefited from the migration of the world’s economic and ornamental plants which has taken place through several millennia. Basic food crops like wheat and barley were brought by early colonizers from Western Asia, the cradle of Western civilization, to India. Traces of these cereals found in the remains of Mohenjo-Daro and Harappa in the Indus Valley civilization suggest links with ancient Mesopotamia. Indian sugarcane noted in the Artharveda (before 800 BC) had reached the eastern Mediterranean sometime after AD 636 by way of Iran. Rice cultivation had spread from the Far East across India to Mesopotamia by the seventh century BC. Very likely the crops of China and Japan reached South Asia through the valleys of Assam or the sea route around the Malay Archipelago. The orange, believed to have originated in China, is mentioned for the first time in Indian literature in the Caraka Samhita, a medical treatise of AD 100 or earlier. Another well-known citrus fruit common in the tropics, the sour lime (Citrus aurantiifolia), is a native of India. Tamarindus indica, cultivated in many parts of India, may have been brought to India through the agency of Arab traders who are also credited with transporting the African baobab (Adansonia digitata) to the west coast, probably during Mughal times.
Transportation Of Plants
Authors: Desmond Ray
Published: November 2023

The global traffic in plants had more failures than successes until 1833 when Dr Nathaniel Ward invented the Wardian case. Tender exotics were especially susceptible to climatic changes on voyages of several months’ duration, and for much of the seventeenth century British botanists and gardeners concentrated on hardy North American plants which had only to endure the relatively short passage across the Atlantic. We learn from Van Reede’s despatch in March 1691 to his Governors, Directors, and Commanders in the Cape, Persia, India, and Ceylon that seeds from their outposts were not fit for sowing when they reached Holland, the result, possibly, of either being too old when collected or having been packed in damp conditions. His advice was that preference should always be given to ‘young, hard and bone-dry seeds’. It would seem that those sent in bags were more prone to decay than boxed consignments.
Epilogue
Authors: Desmond Ray
Published: November 2023

In January 1907 Sir Joseph Hooker complained to J. S. Gamble at Dehr a Dun that ‘ Botany seems to be dead in India ’ 1. With the disintegration of the Botanical Survey of India there was now no central authority to speak on behalf of botany, no organized scientific opinion to command the attention and respect of the Government of India.
Morphogenesis-related changes in extracellular matrix induced by retinoic acid
Authors: Morriss-Kay Gillian , Mahmood Radma
Published: November 2023

Retinoic acid (RA) is a “classic” teratogen in that it induces different patterns of malformations when mammalian embryos are exposed to it at different developmental stages. The developmental stage at which exposure to a teratogen leads to a specific malformation outcome is the critical period for that teratogen and malformation. For instance, the critical period for RA-induced craniofacial malformations is at or before the early neural plate stage of development; cleft palate and limb reduction defects have their own critical periods at later stages of embryogenesis. Investigation of developmental events at the time of the critical period, in both normal and RA-treated embryos, can provide important insights into both the normal roles of RA and the early alterations at the onset of abnormal development. At the critical period for craniofacial malformation, embryonic structure is relatively simple (Fig. 13.l(a)), consisting of neural plate and primitive streak regions. In the primitive streak region, epithelial cells of the epiblast are converted to mesenchyme; these “primary mesenchyme” cells migrate laterally and rostrally (anteriorly) within a glycosaminoglycan-rich extracellular matrix (Morriss and Solursh 1978a). Primary mesenchyme cells underlying the neural plate have a more elaborately structured matrix (sec Fig. 13.4(a)), so that this part of the embryo has the characteristic appearance of interacting tissues. In this article we consider the possibility that early events in RA-induced craniofacial malformations involve alteration of the molecular composition and physical structure of the extracellular matrix. We begin by considering the evidence for identifying the early neural plate stage as the critical period.
The cloning of tumour suppressor genes
Authors: Housman David E
Published: November 2023

The identification of a class of genes whose action is required to regulate cell growth and whose absence leads to unregulated cell proliferation can be attributed to two lines of experimental investigation. The term tumour suppressor gene is most clearly associated with the pioneering somatic cell genetic work of Dr Harris and his collaborators and contemporaries in the late 1970s. Terms such as anti-oncogene were first associated with the work of Knudson (1971) and his collaborators who carried out a statistical analysis of the age of onset of childhood cancers and suggested that a specific small number of rate-limiting events was involved in the aetiology of childhood cancers and that hereditary predisposition could reduce the number of such steps to a single rate-limiting event. These two intellectual pathways in fact crossed and merged in the late 1980s and early 1990s. The demonstration that a series of genes exhibiting precisely the characteristics of these negative regulators of cell growth played a key role in the aetiology of a series of both childhood and adult cancers has led to a dramatic shift in our perception of the pathway to tumorigenesis. The number of tumour suppressor genes which have thus far been isolated and characterized remains small relative to the number of oncogenes identified to date.
Cunoniaceae
Authors: Bauera Mary Gregory
Published: November 2023

This family consists of about 25 genera and around 350 species of evergreen shrubs and small to large trees, rarely climbers (Aphanopetalum), ranging from tropical rainforests to dry sclerophyll woodlands. Distribution is mainly in the southern hemisphere, especially in Australia, New Guinea and New Caledonia.
Montiniaceae
Authors: Gregory Mary
Published: November 2023

Takhtajan (1983) considered this family to consist of the monotypic Montinia Thunb., a shrub with a distribution in mountainous areas of southern Africa to Angoia, and Grevea Baillon, which has three species, one is a liana growing in west central Africa, and two are tree species occurring in east Africa (one of them present in Madagascar also). A third monospecific genus, Kaliphora Hook. f., which is a Madagascan endemic with the habit of a shrub or small tree, growing in evergreen forests, was doubtfully placed by Takhtajan in the Melanophyllaceae (Cornales), but work by Ramamonjiarisoa (1980) and Carlquist (1989) suggests it is better placed here.
Saxifragaceae
Authors: Gornall By R J
Published: November 2023

The circumscnpt10n of this family corresponds to Engler’s tribe Saxifrageae minus Vahlia Thunb. (Takhtajan 1987). The latter is better placed in its own family on account of aspects of its anatomy, chemistry and embryology (q.v.). The Saxifragaceae thus consist of about 600 species in about 30 genera, of which the largest is Saxifraga L. with about 450 species. The plants are herbaceous, rhizomatous (rarely bulbiliferous) perennials (monocarpic in some Saxifraga species), or occasionally biennials or annuals (some Saxifraga species). The family has a chiefly montane, holarctic distribution, although its range extends southwards down the Andean cordillera to Tierra del Fuego. Western N. America and eastern Asia are centres of diversity for the family in terms of genera represented.
Droseraceae
Authors: Gregory Mary
Published: November 2023

This family comprises four genera of carnivorous plants: Drosera L. has about 125 species, while the other three genera are monospecific. Aldrovanda L. is an aquatic, rootless herb with a world-wide distribution excluding the New World and Pacific. Dionaea Ellis (Venus’s flytrap) grows in semi-savannah areas in N011h and South Carolina, USA, and Drosophyllum Link is a scrambler or sub-shmb, restricted to Portugal, Spain and Morocco, mainly in coastal areas. Drosera occurs world-wide, but about half the species are confined to SW Western Australia; most species have basal rosettes, others have leafy stems and a few species are climbers; vegetative reproduction is common, by tubers, stolons, rhizomes, and leaf buds (gemmae). In general, carnivorous plants are intolerant of shade and grow in soils poor in nutrients, which may be subject at times to water-logging and fires.
The scale of the human enterprise and biodiversity loss
Authors: Ehrlich Paul R
Published: November 2023

Since every species and population can be assigned intrinsic (and perhaps practical) value, we should be concerned with both the number and rate of extinctions (P. R. Ehrlich and A. H. Ehrlich 1981,1992). It also seems reasonable to place value on the proportion of a higher taxon that is disappearing: the annual loss of 1000 species from the class Aves would be considered as substantially more serious than the loss of 1000 species from the class Insecta, and the extinction of the only remaining coelocanth would be deemed a scientific tragedy.
The Flora Graeca Story
Authors: Walter Lack H , Mabberley David J
Published: November 2023

This is the first scholarly treatise that tells the remarkable story behind the making of the Flora Graeca, the monumental collection of illustrations and descriptions of plants in Greece, Cyprus and Turkey. First described by Dioskorides in the sixth century, the flora and fauna of the Levant was neglected until the gentlemen botanists-naturalists John Sibthorp and John Hawkins, accompanied by illustrator Ferdinand Bauer, travelled there. Bauer produced a class of paintings superior to anthing of their kind in existence then, and his work was to become one of the most valuable treasures of the University of Oxford. Based on the original diaries, letters, and specimens, this fine work is illustrated with the original illustrations which are still housed at the Department of Plant Sciences there.
Bauer’s Work for Sibthorp and Hawkins
Authors: Walter Lack H , Mabberley David J
Published: November 2023

Whereas Sibthorp had come home to Cowley House, Bauer arrived in a country he had never visited and a visited where he knew no one; he was a foreigner and his command of English was poor. Being neither a professor. a don, nor a student, he did not belong to Oxford society—effectively the university—but was only the draughtsman of the Sherardian Professor. thus ranking just slightly above a servant. The Oxford winters were less cold than those in Feldsbcrg, the summers less hot, but more important for an illustrator working with colour there were many grey days with a reduced quality of the light. Bauer had to adapt.
The Biology Of Hymenoptera
Authors: Hanson Paul E , Gauld Ian D
Published: November 2023

In Costa Rica hymenopterans have been collected in all major terrestrial habitats, from the coastal man grove swamps to the peaks of the highest mountains. Although none has yet actually been collected in fresh water, a species of Hydrophylita, a trichogrammatid genus known to attack submerged eggs of dragonflies, has recently been captured in Malaise traps in the country (see Chapter 11.19). The different life zones referred to in Chapter 1 support rather different hymenopterous communities. In the hot, seasonally dry and rather open tropical deciduous forests of the northwest a variety of aculeates are relatively common, including representatives of small and bio logically little-studied groups such as the Sierolomorphidae and brachycistidine Tiphiidae. In these dry forests several species of the larger Hymenoptera are yellow and brown or brown and blackish banded. Some ichneumonid species are dichromic, with a yellow ochre and brown patterned individuals in dry forests and a black and lemon yellow coloured individuals in wet forests or in dry forests during the wet season (Gauld, 1991). As one moves from the deciduous forest to the lowland moist or wet forests the number of social insect species apparently increases (e.g. see Janzen, 1983). Species of stingless bees and ants abound, as do the less noticeable non social, but numerous, yellow and black patterned chalcidids, whose hovering flight resembles that of stingless-bees, and the tiny orange and black scelionids that parasitize katydid eggs. Reddish braconids with dark patterned wings may be seen among the under growth while black and white banded ichneumonids are occasionally glimpsed, almost invisible as they fly through shafts of sunlight.
Economic importance of Hymenoptera
Authors: Hanson E
Published: November 2023

From the human perspective, no other group of insects contains so many beneficial species as the order Hymenoptera. The majority of hymenopterans have larval stages that are carnivorous on other insects and numerous species are vital in controlling the populations of pest insects. Among the non carnivorous members of the order, bees constitute the single most important group of plant pollinators. One species of bee, the honey-bee, is the most prevalent domesticated insect and provides us with honey, wax, and other products. On the other hand, the order Hymenoptera also contains some very serious pest species. Leaf-cutting ants are among the most damaging agricultural pests in the Neotropics. Many ants, wasps, and bees are capable of inflicting painful stings, and in persons who develop a hypersensitive reaction to the venom, a sting can be fatal.
The orussids and stephanids
Authors: Hanson Paul E , Gauld Ian D
Published: November 2023

The traditional division of the order Hymenoptera into two suborders, the ‘Symphyta ‘ and Apocrita, is increasingly difficult to maintain since the characters used to unite the ‘Symphyta ‘ are mostly shared plesiomorphies. Moreover, there are several apomorphic characters that unite the Orussidae with the Apocrita, although orussids are usually classified in the ‘Symphyta ‘ (see Chapter 5). In our opinion, these features coupled with the fact that orussids develop as parasitoids, are an overwhelming argument for treating the Orussidae separately from the sawflies and woodwasps, thereby breaking with the convention of maintaining the symphytan/ apocritan divide. Although the Orussidae and Stephanidae probably do not comprise a monophyletic group, they are both primitive families of parasitoids. Both comprise species that are idiobiont ectoparasitoids of wood-boring insects, which is thought to be the ancestral biology of Apocrita (Gauld, 1988c). Therefore, if for no other reason, it is biologically convenient to treat these two families together.
Male mate choice and intrasexual competition
Authors: Ligon J David
Published: November 2023

This chapter deals briefly with two other issues that, together with female mate choice, make up the subject of sexual selection. The first is mate choice by male birds. In contrast to female mate choice, this subject has received little attention. The second topic, intrasexual competition for mates and matings, is widely recognized as extremely important in the lives of vertebrate animals. Nevertheless, it too has received far less attention than mate choice by females. Typically, such competition is among males; female-female competition, however, can also be intense in birds and is sometimes even fatally violent.
Cooperative breeding
Authors: Ligon J David
Published: November 2023

Cooperative breeding, sometimes referred to as communal breeding, is a rare and specialized phenomenon that occurs in fewer than three per cent of the world’s approximately 9700 species of extant birds. Cooperative breeding is defined by the presence in a stable social unit of non-breeding ‘helpers’, which assist in the care of young birds, in addition to breeding individuals (from a single pair to several or even most group members).
Migration across ecosystem boundaries
Authors: Dyson-Hudson Rada , Meekers Dominique
Published: November 2023

Migration across ecosystem boundaries is the third parameter which determines population replacement and persistence, the others being fertility and mortality. Migration can contribute either to population increase or population decrease. Because migration is reversible—people who leave can later return—and because migration rates can change rapidly, it would seem to be an effective mechanism for maintaining a balance between people and resources in a highly fluctuating environment like South Turkana. McCabe (1984, 1987) documented the importance of short-term movement by marginal people out of the pastoral sector as a mechanism of coping with drought. In this chapter, we focus on longer-term migrations out of the pastoral sector for one year or more, and discuss the effects on ecosystem function of both short-term and long-term migration across the boundaries of the South Turkana pastoral production system.
Targeting the tumour endothelium using specific antibodies
Authors: Derbyshire Elaine J , Thorpe Philip E
Published: November 2023

Monoclonal antibodies have been considered for many years as a means to deliver cytotoxic agents specifically to tumour cells. While the approach has proved promising in clinical trials of leukaemia and lymphoma (1,2), the results of antibody trials in solid tumours, which account for 90% of malignancies (3), have so far been disappointing (4,5).
The Biology of Polar Habitats
Authors: Fogg G E
Published: November 2023

This book is unique in providing a comparative overview of life at the two Poles, from ice caps to tundra and open ocean. It describes their physical characteristics, the communities of microorganisms, plants, and animals inhabiting them, and their interactions with the global environment. Fogg considers the origins of polar habitats, their subsequent colonization and population dynamics, and assesses the effects of human activities on the Pole, focusing on the changes that may result from global warming and stratospheric ozone depletion. The author has wide experience in marine and terrestrial ecology, and his background of research in both the Arctic and Antarctic is reflected in the book. This is the most authoritative and up-to-date volume currently available on polar biology. The text is clear and lively, well illustrated, and supplemented with ample references for further reading. It provides and excellent introduction for anyone intending to work in the polar regions, and will be ideal for students taking undergraduate and post-graduate courses in biology, ecology, microbial ecology, geography, and conservation.
Sound production and acoustic communication in Xenopus borealis
Authors: Yager David D
Published: November 2023

Xenopus has an underwater acoustic communication system based on simple clicks arranged in different temporal patterns. Focusing on X. borealis, I have found a sound production mechanism highly adapted to the underwater environment-in contrast to terrestrial anurans, these frogs do not use a moving air column to produce their vocalizations. The larynx of the male is enormously enlarged to form an internal vocal sac. The arytenoid cartilages are modified to form two discs whose smooth medial surfaces are normally tightly apposed. When contraction of bipennate laryngeal muscles causes the discs to separate with high acceleration, a single click results. The click is most probably produced by an ‘implosion’ as air rushes into the cleft between the discs. The frequency spectrum of the click is determined by the vibrational characteristics of the laryngeal walls.
The biology of Xenopus tadpoles
Authors: Wassersug Ichard
Published: November 2023

Virtually all that is known about the biology of Xenopus larvae comes from laboratory studies of one species, Xenopus laevis. This account reviews several aspects of larval biology, especially feeding, respiration, schooling behaviour, swimming mechanics and certain visceral functions. Compared to tadpoles in other genera, Xenopus larvae are highly specialized, obligatory microphagous tadpoles. Many of their unique morphological features testify to their efficiency as suspension feeders. Xenopus larvae are also obligatorily air-breathers and must intermittently surface for air in order to have normal growth rates. Xenopus tadpoles are social and use both visual and lateral line information to maintain school geometry.
Skin secretions of Xenopus laevis
Authors: Kreil Gunther
Published: November 2023

A variety of peptides, enzymes and other proteins have been isolated from skin secretions of Amphibia. Among the peptides at least three different groups can be discerned: (1) those with structural and functional homology to mammalian hormones and neurotransmitters; (2) antimicrobial peptides of different types, one being characterized by the propensity to form amphipathic helices; and (3) opioid peptides containing a D-amino acid essential for biological activity, for which no mammalian counterparts have so far been found. Of the first group, thyrotropin releasing hormone, caerulein (related to mammalian cholecystokinin) and xenopsin have been isolated from skin secretions of X. laevis. cDNA cloning has been used to elucidate the structure of the precursors of these peptides. Moreover, the antimicrobial peptides PGS/magainins I and II, PGLa and several others have been studied in detail. Several enzymes involved in the processing of peptide precursors to the final product have also been isolated from skin secretions of X. laevis.Recent studies with skin secretions of frogs from other families of amphibian species have yielded similar results. These have also been found to contain numerous peptides; in particular, a large number of peptides with antimicrobial properties have been discovered in the past years.