bluuebunny/crossref_metadata_2025 huggingface dataset:
Neuropathic pain in the orofacial area
Authors: Jääskeläinen Satu K
Published: November 2023

Peripheral sensory nerve injury nearly always leads to some degree of subjective sensory impairment. In ideal circumstances, this can be diagnosed in a clinical sensory examination as a decrease or total loss of sensation of one or several sensory modalities within the affected nerve distribution. While the negative symptoms and signs of hypoesthesia are essential for the diagnosis of a neuropathy, some patients also develop one or more positive sensory signs including pain, allodynia, paraesthesia, and hyperesthesia. Within the trigeminal distribution, these positive phenomena may severely interfere with vital and socially important functions, e.g. mimics, eating, speaking, teeth brushing, and kissing. The sensory hypoesthesia caused by sensory nerve fibre damage may be so subtle, however, that it cannot be detected in the rather crude clinical sensory examination.
Platyhelminthes, Nematoda, Nemertea
Authors: Gibson R , Knight-Jones E W
Published: November 2023

The platyhelminths, or flatworms, are bilaterally symmetrical, pseudocoelomate animals with soft, dorso-ventrally flattened bodies. The body shows marked cephalization, but is unsegmented, although in the Cestoda serial budding, or strobilization, of identical proglottids posterior to the scolex gives rise to an apparently segmented body. The outer body wall is a ciliated epithelium in freeliving flatworms, and a non-ciliated syncytial tegument in parasitic forms; no class includes species with an outer cuticle. The bulk of the flatworm body consists of a heterogeneous parenchyma in a liquid matrix. The digestive tract is characteristically incomplete; in most groups an anus is lacking, and the entire gut is absent in many symbiotic or parasitic species. Excretion, and perhaps osmoregulation, are carried out by single-celled protonephridia, or flame cells. Most species of flatworm are hermaphroditic. Reproductive structures, reproductive behaviour, and life cycles are often complex and display numerous adaptive features throughout the phylum.
Annelida
Authors: Nelson-Smith A , Knight-Jones, P , Knight-Jones E W
Published: November 2023

The annelids or ‘true’ worms form a major animal group, typically of elongated cylindrical shape and mostly ranging in length from 10mm to 150mm (although some are microscopic and a few exceed I m); the body is characteristically made up of a series of ring-like segments, indicated externally by annular constrictions. The relatively simple gut normally passes down the body from an anterior subterminal mouth to a posterior terminal anus. The first segment (prostomium) (Fig. 6.1) is situated above and in front of the mouth, the second (buccal segment or peristomium) surrounds it and the last (pygidium) encircles the anus. The segments in between (which, in the growing worm, are added to the body just anterior to the pygidium) primitively more or less resemble each other, each containing a similar complement of organs. This may be expressed externally by a segmental series of similar pores or protruding structures, particularly those used in locomotion. Movement is normally achieved by the action of body-wall muscles on the fluid-filled coelomic (body) cavity, producing peristaltic waves of contraction or sigmoid rippling of the body. In the polychaetes, which are entirely aquatic and regarded as the basic annelid stock, a typical body segment carries on each side a parapod (Fig. 6.1) comprising various well-developed fleshy lobes and a large number of chitinous bristles (chaetae); in unhurried locomotion on a solid substratum, these may function like short legs and, in many, they also aid swimming as the body flexes more rapidly in a horizontal plane. In the oligochaetes, fleshy outgrowths are lacking and the chaetae are fewer; amongst aquatic species, they may still be numerous and quite long, although the more familiar earthworms have only few, short enough to be almost invisible. The leeches (Hirudinea) lack bristles; using their terminal suckers, they may move along a solid surface by ‘looping’. When swimming, the dors<>-ventrally flattened body reflects this action by flexing in a vertical plane.
Chelicerata, Uniramia, And Tardigrada
Authors: Elliot P , King P E , Morgan C I , Pugh P J A , Smith, A , Wheeler S L A
Published: November 2023

Psecoscorpions have a superficial resemblance to true scorpions, with their characteristic, large, chelate pedipalps. However, they differ from true scorpions in their size (all British species are under 4 mm long), and the fact that they lack a telson and sting. All are predatory. The body is divided into two regions (Fig. 11.1), namely an anterior prosoma bearing two pairs of ocelli (=eyes), and the body appendages; and a posterior opisthosoma. The prosoma is armoured dorsally by a carapace bearing the ocelli, the anterior margin is often serrated forming a species characteristic epistome. Ventrally, the prosoma is armoured by the leg coxae. The first pair of body appendages are the chelicerae—complex two segmented pre-oral structures; basically they comprise a large basal segment which is produced to form a fixed digit, and a subapical moveable digit which extends parallel with the fixed digit and acts against it to form a chelate pincer. The two digits are ornamented with a number of structures, including serrula interior and flagellum on the fixed digit; and serrula exterior and galea on the moveable digit (Fig. 1I. 1). The complexity of the chelicerae is a result of their carrying out a number of varied roles, they not only function during feeding, but also in silk production and grooming.
Sites Stratified Within the Kbs Tuff: Reports
Authors: Isaac Glynn Ll. , Harris John w. K , Kaufulu Zefe M
Published: November 2023

In broken badlands topography on the northern slopes of the Aberegaya Ridge in Area ro5 the headward erosion of a series of third-order tributary gullies has cut into a localized body of the KBS Tuff (Plate 3.1A, B). The tuff outcrop thus formed makes up part of a small spur that trends northeastwards from the middle-level slopes of the ridge (sec Fig. 2.10; Plate 3.1B). A concentration of artefacts and bone fragments was found on and in the KBS Tuff at a point where the tuff outcrop forms a small saddle near the origin of the spur (Fig. 3.1, Plate 3.2A, B). This concentration was designated KBS (Kay Behrensmeyer Site) (M. D. Leakey 1970; R. E. Leakey 1970a) and later catalogued as FxJi I. The site serves as the type locality for the ‘KBS Tuff’ for which it provided a name.
The Lophophorate Phyla Phoronida, Bryozoa, And Brachiopoda
Authors: Ryland J S
Published: November 2023

The Phoronida, Bryozoa, and Brachiopoda are smallish phyla of quite different outward appearance; yet they are linked by a common body plan. In all three the body is coelomate and divided into three regions. The mouth is situated within the lophophore, which is a crescentic or annular ridge bearing slender ciliated tentacles and morphologically an extension of the meso-some (middle region). The alimentary canal is deeply recurved, with the anus opening near but outside the lophophore. The three may conveniently be grouped as the lophophorate phyla. Despite their fundamental similarities, members of the three phyla would never be confused. Phoronids are small, tubicolous worms bearing the lophophore anteriorly; bryozoans form colonies consisting of great numbers of microscopic zooids; and brachiopods are superficially lamellibranch-like, living within a bivalved shell. The phyla are considered in the sequence Phoronida, Bryozoa (p. 797), and Brachiopoda (p. 833).
World distribution
Authors: Flux John E C
Published: November 2023

Like most pests and game animals, rabbits (which are both) now have a distribution strongly influenced by man. The association extends back for thousands of years: bones near Nice show signs of slaughter by man as long as 120 000 years ago (Pages 1980). Many fossils from the upper Pliocene and Pleistocene of southern Europe from Britain to Italy, however, are suspect because the rabbits may have died after burrowing into older strata. Zeuner (1963) accepts only the upper Pleistocene records from Gibraltar and an early post-glacial record from southern France. Corbet (1986) considers the mid Pleistocene specimen from Kent consistent with similar finds in France and Spain, pointing to a rather more widespread distribution before the final glaciations. Three thousand years ago they seem to have been restricted to Spain, where Phoenicians recorded them as abundant about 1100 BC, and perhaps southern France (Beaucournu 1980). There is no good evidence that they were indigenous in North Africa (Barrett-Hamilton 1912; Beaucournu 1980; Corbet 1986). H0vvever, most genera of leporids except Lepus and Syh1ilagus have remarkably small, isolated distributions and the restriction of Oryctolagus to Spain is not unduly surprising.
Predators, parasites, and defence
Authors: Hopkin Stephen p. , Read Helen J
Published: November 2023

There is surprisingly little quantitative information on the numbers of millipedes that fall victim to predation. Most information derives from anecdotes, or when millipedes turn up in the gut contents of vertebrates. A wide range of invertebrates, amphibians, reptiles, birds, and mammals will take millipedes in captivity (Baker 1985b; Remy 1950). However, it is by no means clear that the same predators will take them in the wild. The early stadia must be much more vulnerable than the adults, but there is very little information on predation of juveniles. Baker (1974) reported that early stadia of Brachydesmus superus are eaten by the mite Pergamasus quisquiliarum. Numerous eggs must also fall victim to soil scavengers.
The Chromophyta, Past And Present
Authors: Christensen Tyge
Published: November 2023

The division name ‘Chromophycées’ was introduced by Chadefaud to comprise the larger algal groups with dorsoventral swarmers and no intraplastidial starch. Bourrelly changed it to ‘Chromophytes’, and Christensen redefined it, as ‘Chromophyta’, to cover all algal classes with swarmer formation and without chlorophyll b, thereby excluding the Euglcnophyceae. With this latter definition the designation has been widely accepted, by some as the name of a taxonomic group and by others just as a useful common label for several algal groups derived independently from non-algal ancestors.
Chromophyte Chloroplasts_A Polyphyletic Origin?
Authors: Whatley Jean M
Published: November 2023

It has become widely accepted that chloroplasts evolved from photosynthetic endosymbionts. Much of the information which gave support to the hypothesis came from ultrastructural investigations. More recently, information acquired from new investigative techniques such as nucleotide sequencing and analysis of antibody cross-reactivity, has also provided support for the general concept, but has as yet been too limited in scope to provide the hoped for answers to important questions about the number of acts of endosymbiosis, the relationships between organisms, and the order in which events occurred. The chromophyte algae with their complex chloroplasts, which may have evolved from eukaryotic endosymbionts, present particular investigative problems. Thus, the numbers and identities of both the endosymbiotic sources and the host cells which engulfed them remain obscure. Nevertheless, as more information is obtained, the relationships between these algae will become clarified. Furthermore, the data accumulating about modern protists and their photosynthetic endosymbionts, should provide a useful basis for understanding the numerous evolutionary steps required to produce the closely integrated partnership between a cell and its chloroplasts.
The Flagellar Base Ultrastructure And Phylogeny Of Chromophytes
Authors: Preisig Hans R
Published: November 2023

The 9 + 2 pattern of microtubules in flagella and the architecture of basal bodies are examples of extreme conservatism because these patterns occur in diverse groups of organisms. On the other hand, some structures at the flagellar base are extremely diverse when higher taxa (from order to class level) are compared, but vary relatively little within these taxa. In the chromophytes such features include the transition region at the base of the external flagellum, and connecting fibres and flagellar roots associated with the basal bodies. The available evidence indicates that these features are useful markers of phylogenetic relationships in chromophyte organisms.
The Evolutionary Origin Of The Brown Algae: Information From Studies Of Motile Cell Ultrastructure
Authors: O’kelly Charles J
Published: November 2023

The ultrastructural features of brown algal motile cells, reconstructed in three dimensions from serial sections, are remarkably uniform over a wide range of taxa. When the ‘typical’ brown algal swarmer is compared with motile cells of other chromophytes, those of the Chrysomeridales, a small group of multicellular golden marine algae, have the most features in common, and from this and other evidence these algae appear to be the closest living relatives to the Phaeophyceae. The taxonomic position of the Chrysomeridales is uncertain. Chrysomeridalean algae usually have been placed in the Chrysophyceae, but their motile cell features differ from those of ‘typical’ ochromonadalean chrysophytes. Moreover, the concept of the Chrysophyceaeis becoming increasingly fragmented. The absence from chrysomeridalean algae of such diagnostic brown algal features as plasmodesmata, alginates, and unilocular sporangia does not permit referral of this order to the Phaeophyceae.
Some Affinities Of The Raphidophyceae With Other Chromophyte Algae
Authors: Heywood Peter
Published: November 2023

Some characteristics of the raphidophycean genera, Chattonella, Fibrocapsa, Gonyostomum, Heterosigma, Merotricha, Olisthodiscus, and Vacuolaria are reviewed to determine possible affinities with other members of the Chromophyta. Information from ultrastructure, cell biology, and molecular biology indicates both shared features within the Chromophyta (for example, presence of chlorophylls a, c  1, c  2 arrangement of thylakoids, tubular ciliary hairs, tubular nature of the mitochondrial cristae), and features apparently characteristic of the Raphidophyceae, for example, the layered structure component of the cytoskeleton which does not appear to occur in other Chromophyta. The layered structure, the complex arrangement of the rhizoplast and rhizostyle, and the absence of a transitional helix mean that the cilia and their associated cytoskeleton present a distinctive combination of features that should be useful in defining the Raphidophyceae.
Introduction And Relationships Of The Group
Authors: Bone Q , Kapp H , Pierrot-Bults A C
Published: November 2023

Chaetognaths are found in every marine habitat, from the benthos to all zones of coastal waters and the open oceans. Although small (2–120 mm long) they are often abundant, and play an important role in the marine food web as the primary predators of copepods. The biomass of chaetognaths has been estimated as 10-30 per cent of that of copepods in the world oceans, so that they are of great significance in transferring energy from copepods to higher trophic levels.
Systematics of The Chaetognatha
Authors: Bieri Robert
Published: November 2023

In recent years the number of species, genera, and families within the Chaetognaths has exploded. In his revision of the phylum Ritter-Záhony (1911a) recognized 27 species in six genera. In his 1965a revision, Tokioka recognized 58 species in 15 genera. Twenty-three years after Tokioka’s revision, 115 species in 23 genera are currently under discussion among chaetognath specialists and this latter list is conservative—it omits an additional 31 species and five genera discussed by Kassatkina (1982). If these were included, the number of genera would jump to 28 and the number of species to 146.
Collection and Chemical Analysis of Chaetognaths and Changes Due To Preservation
Authors: Conway D V P , Robins D B
Published: November 2023

Chaetognaths are recognized as a key component in the marine food web (Reeve 1970a; Sameoto 1972; Kotori 1976; Szyper 1978; Hopkins 1982; Feigenbaum and Maris 1984; Angel 1989) but much of the basic information on the relationship between their length, weight and chemical composition is not generally available in sufficient detail for the study of energy movement through the web. Available data are scattered through the literature, are often based on very few measurements, and with few exceptions, are not detailed for any one species. In addition, the methods used are not standardized and are sometimes only superficially described.
New and interesting records of Tanzanian foliicolous lichens
Authors: Farkas E
Published: November 2023

A total of 98 species of obligately foliicolous lichens is recorded to date from submontane and montane rainforests of the Usambara Mountains, Tanzania, due mainly to collections made during the Usambara Rain Forest Project expeditions. 35 species are new to the Usambaras including 15 species new also to Tanzania and 6 to Africa. Seven species are described by Farkas and Vezda as new to science: Porina sphaerocephaloides Farkas: Macentina borhidii Farkas and Vezda; Dimerellaflavicans Vezda and Farkas; D. pocsii Vezda and Farkas; D. tanzanica Vezda and Farkas; D. usambarensis Vezda and Farkas, and Byssoloma usambarense Vezda. 36 species belong to Arthoniaceae, Opegraphaceae, and genera with pyrenocarpous ascomata.
Observations on the composition and distribution of the ‘Lobarion’ in fores ts of South East Asia
Authors: Wolseley P A
Published: November 2023

Members of the Lobariaceae contribute to a distinctive and well developed epiphytic community of lichens and bryophytes associated with forests in temperate and tropical regions. Forest macrolichens in Indonesia, Malaysia, and Thailand arc compared with those found within the European alliance Loharion pulmonariae. Factors affecting the location and distribution of the ‘Loharion’ in a range of tropical forests are considered. Aspects of the distribution of some critical genera arc discussed. Present practices of forest management and widespread degradation in South East Asia have profound affects on the distribution of this characteristic lichen community.
Introduction to the evolutionary biology of the threespine stickleback
Authors: Bell Michael A , Foster Susan A
Published: November 2023

The threespine stickleback, Gasterosteus aculeatus, is a species complex that comprises thousands of phenotypically diverse populations. It is widely distributed in boreal and temperate regions of the northern hemisphere and inhabits coastal marine waters, brackish waters, and a wide array of freshwater habitats. Its broad geographical and ecological distribution and the fragmentation of its gene pool into many thousands of isolated or semiisolated demes in freshwater habitats have generated an extraordinary range of phenotypic diversity. In some instances, divergent populations have acquired the isolating mechanisms that characterize biological species. This phenotypic diversity offers an exceptional opportunity for analysis of evolutionary mechanisms.
Energy allocation in the threespine stickleback
Authors: Wootton R J
Published: November 2023

Energy is the basic currency of living organisms (Harold 1986). It gives the organism the potential to do the work required for maintenance, growth, and reproduction. Organisms are subject to the laws of thermodynamics (Brafield and Llewellyn 1982), making it possible to describe quantitatively the expenditure of energy. All forms of energy are interconvertible and so can be measured in common units of joules (J) (1 J = 4.18 cal).
Predators and Morphological Evolution in Threespine Stickleback
Authors: Reimchen Thomas E
Published: November 2023

The wealth of investigations on threespine stickleback during the last half-century has established the species as a model organism for evaluating population differentiation. Stickleback are particularly attractive for these studies because they exhibit extensive variability within and among populations and occurs in a diversity of habitats, from open oceanic waters to isolated bog ponds. Differences in predation levels, which are an underlying theme in diverse studies of prey defences (Curio 1976; Endler 1986; Vermeij 1987; Greene 1988), are also suspected of occurring among stickleback populations and are associated with increased expression of spines, bony armour, and escape responses (Hagen and Gilbertson 1972; Moodie and Reimchen 1976a; Gross 1977; Giles and Huntingford 1984; reviews in Wootton 1976 and Bell 1984a
Adaptive variation in antipredator behaviour in threespine stickleback
Authors: Huntingf ord F A , Wright P J , Tierney J F
Published: November 2023

A major aim in behavioural ecology is to understand how natural selection acts on behavioural variants. One way of unravelling the relationship between phenotype and selection is the comparative approach, in which behavioural variants are related to environmental features (Huntingford 1984; Krebs and Davies 1987). If a behavioural trait (for example, the removal of egg shells by parents after young gulls hatch) is regularly associated with a particular environmental factor (for example, risk of predation on chicks), it is likely that the former is an adaptation to the latter (Tinbergen et al. 1962). However, behavioural phenotypes are notoriously labile, so differences among populations may reflect flexible responses of the animals to environmental differences as well as evolved hereditary adaptations. Behavioural differences among populations can only be considered as the result of natural selection if a genetic basis for the behavioural differences can be demonstrated.
Evolution of the reproductive behaviour of threespine stickleback
Authors: Foster Susan A
Published: November 2023

Ethologists have been interested in understanding evolutionary processes that structure behavioural patterns since the turn of the century (e.g. Whitman 1899; Heinroth 1911), or even earlier if Charles Darwin may be included among the ranks of ethologists (Darwin 1872). Typically, comparisons have been made among closely related species in an effort to examine historical sequences in phenotypic evolution and to determine the extent to which behavioural phenotypes have been influenced by phylogenetic history. These efforts have demonstrated clearly that at least some behavioural phenotypes are strongly conserved over long time periods in phylogeny and can therefore reflect the patterns of phylogenetic diversification within a clade (reviewed in Lauder 1986; McLennan et al. 1988; Burghardt and Gittleman 1990; Brooks and McLennan 1991).
Prologue
Authors: Stearns Stephen C
Published: November 2023

In a forest just south of the Rhine, old and dense with oak and beech, a tree falls in an equinoctial storm. A beech seed germinates in the clearing left by the falling tree. It grows rapidly, escapes the attention of slugs during its first summer, overtops the competing grasses and shrubs, and pushes its crown into the narrowing circle of sky overhead. As its branches near the canopy, it begins to flower. It is 50 years old. Its growth then decelerates until, at more than 200 years of age, when it is two metres thick at breast height and fifty metres tall, further growth is no longer measurable. Every few years, it flowers heavily and sets abundant seed. Much is eaten by flocks of wintering bramblings. Some is scattered by winter storms. The seeds drop in various directions, more near the tree, a few at some distance. In the 154th year of its life, its pollen enters an ovule on a beech half a kilometre away whose seed survives to flower. In the 268th year of its life, a hornbeam falls about 80 metres away. One seed sprouts in the clearing and starts its climb to the canopy. Of the millions of seeds that the tree produces, only this one will survive to flower. It has produced two offspring that survived to reproduce, one through pollen, one through seed.
Diversity of flagellates without mitochondria
Authors: Mylnikov A P
Published: November 2023

Flagellates without mitochondria are mostly found in anaerobic, microaerophilic, or organically enriched sites. The genera are: Pelomyxa, Mastigina, Mastigella, Mastigamoeba, Phreatamoeba (all pelobionts); Retortamonas and Chilomastix (representing the retortamonads); Gyromonas, Hexamita, Trigonomonas, and Trepomonas (diplomonads); and Pseudotrichomonas (representing the trichomonads). Free-living flagellates of anaerobic habitats are dominated by forms without mitochondria, and are assignable to the pelobionts, retortamonads diplomonads, and trichomonads.
Organization of cryptomonads
Authors: Kugrens Paul , Lee Robert E
Published: November 2023

The cellular features of a mixotrophic Chroomonas, and of the hetcrotrophic genera Chilomonas and Goniomonas are presented. Chroomonas is photosynthetic and has chloroplasts typical of cryptomonads, yet bacteria arc routinely taken into a large vacuole. Chilomonas has a reduced chloroplast (leucoplast) but bacteria are not ingested. Goniomonas lacks plastids and probably represents a primitive cryptomonad which is capable of ingesting bacteria. Surface architecture, cell coverings, flagella, and internal features of these cells are described.
Genetic Analysis Of Leaf Development
Authors: Hake Sarah , Sinha Neelima
Published: November 2023

Plant development and the processes that control it have interested botanists for centuries. The traditional techniques of histology and plant morphology have been used for many years to generate a large body of knowledge on the generation of plant form. The amount of information that can be gleaned from these approaches has certainly not reached a saturation point, as nature has a large number of variant forms for study. The approaches however, may be limited in the type of information that they can provide. They can describe the mechanics of how a form arises, but the controls of processes that lead to plant form may never be elucidated by these approaches. The time is ripe for plant biology to take advantage of new tools and move into an era where traditional studies can be combined with genetic and molecular techniques leading to a more complete understanding of how plant form is generated.
Assessing Local Distribution of Threatened Species: a Case Study Considering the Threatened Plants of Italy
Authors: Miller* R I , Press† J R , Baldini↕ R M
Published: November 2023

Conservation actions are based on data collected and stored in scientific institutes. Our project was designed to link two museums with an organisation directly concerned with conservation. Italy was chosen as a European pilot study for assessments of distributions of rare and threatened vascular plants listed in the revised appendix of the Berne Convention. We discuss criteria for defining species rarity and selection of appropriate plant groups. The establishment and development of a computerized system for recording data and for monitoring threatened plants, now operational at the Natural History Museum, London, is linked to a Geographical Information System which enables analyses of a wide range of geo-referenced data and production of high quality maps. Finally, a preliminary analysis of distribution patterns of rare plants throughout Italy is given.
The Numbers and Spatial Distributions of Species: Analyses of British Data
Authors: Lawton* J H , Prendergast* J R , Eversham† B C
Published: November 2023

Britain has one of the best known, but most heavily modified floras and faunas of the world. Data on distributions of many taxa allow the presence and absence of species to be mapped in each 10 X 10 km square of the national grid, which can be used to answer questions of interest to both theoretical ecologists and conservationists. For example: (i) Where are the most species-rich areas of the country for particular taxa? (ii) Do diversity ‘hot-spots’ coincide for different taxa? (iii) How much turnover (beta-diversity) is shown by different taxa along geographic transects? (iv) What proportion of the national pool of species in a particular taxon might be conserved by setting aside reserves in a limited number of locations? Superimposed on well-known north-south and east-west gradients in alpha diversity, are significant departures in local species richness.
Basal Taxa and the Role of Cladistic Patterns in the Evaluation of Conservation Priorities: a View from Freshwater
Authors: Stiassny* Melanie L J , De Pinna† MÁRio C C
Published: November 2023

Taxa basal within their lineages are often notably depauperate in numbers of species when compared with their sister-groups, and frequently have extremely restricted geographical distributions. These two features render them particularly vulnerable to environmental pressures. This phenomenon is strikingly prevalent among freshwater fishes, an assemblage representing upward of 25 per cent of all living vertebrates yet largely ignored in most regional biodiversity estimates and conservation evaluation programmes.
Biodiversity, Taxonomic Relatedness, and Endemism in Conservation
Authors: Williams P H , Humphries C J
Published: November 2023

Practical approaches to measuring biodiversity are described. Within any defined geographical area biodiversity is considered to be a measure of two main variables: number of taxa and degrees of difference between taxa. Three approaches for the measurement of biodiversity are described, phenetic, phylogenetic, and cladistic, the latter being considered the most appropriate. Using the computer program WORLDMAP comparative trials of four different measures of cladistic diversity, root-weight, higher taxon richness, spanning-tree length, and cladistic dispersion, were undertaken. Even representation of sub-groups within taxa using the cladistic dispersion measure agrees best with the popular, intuitive ideal of what consititutes the most diverse fauna or flora. The taxonomic measures were used together with a measure of end emism in conjunction with complementarity of floras and faunas to determine priority sequences of areas for conservation. It was concluded that the greatest contribution to the conservation and representation of biodiversity is from complementarity, but differences between organisms can be most readily represented by using available information of group membership from taxonomic classifications. Endemism is not a measure of biodiversity but of range size, and was shown to be ineffective as a means for selecting areas for conservation if not all selected areas could be included.
Cell coverings
Authors: Leadbeater B S C
Published: November 2023

The unit of cell covering in most members of the Isochrysidales, Prymnesiales, and Coccolithophorales is a two-layered microfibrillar scale. The proximal layer consists of a quadriradial pattern of microfibrils. The distal layer is more variable with spiral or interwoven patterns of microfibrils being common. Scales are usually arranged on the cell surface in one or more layers, and in species of Chrysochromulina the distal surface of outerlayer scales is often modified to form a spine, cup, or cylinder. Scale form and substructure is therefore an important taxonomic character at the species level. The coccoliths of some coccolithophorids are based on the characteristic microfibrillar scale. In some species, such as Pleurochrysis carterae, the coccolith baseplate is a two-layered scale whereas in others the scale component may be only represented by a few curved radial microfibrils. In Calyptrosphaera, and the crystallolith-bearing cells of Coccolithus pelagicus, the covering of scales and crystalloliths is bounded distally by a continuous investment.
The haptonema
Authors: Inouye Isao , Kawachi Masanobu
Published: November 2023

Morphological, behavioural, and physiological features of the haptonema are reviewed and their biological significance is discussed. The haptonematal components are arranged in an absolute configuration in relation to the flagellar apparatus and cellular organization, and the direction of bending and coiling is also fixed. Coiling is a Ca2+-mediated phenomenon. The adhesive property of the haptonema is probably related to the presence of concanavalin A-binding substances and/or electric charge associated with the haptonematal surface. Haptonematal functions are provisionally proposed.
Haptophytes as feedstocks in mariculture
Authors: Jeffrey* S W , Brown* M R , Volkmant† J K
Published: November 2023

Mass-cultured microalgae, including haptophytes, are used extensively in mariculture as live feeds for all growth stages of molluscs, for the early larval stages of crustaceans and fish, and for brine shrimp and rotifers that are animal intermediates in mariculture food chains. Temperate strains of Pavlova, and temperate and tropical strains of Isochrysis have been used successfully worldwide for oyster and mussel farming since the 1950s. Microalgae must supply a balanced mixture of key nutrients. As part of a study of the nutritional (biochemical) composition of about 40 species of both classical and new isolates of microalgae from six algal classes, we have identified seven strains of haptophytes from the genera Pavlova and Jsochrysis which show excellent nutritional profiles for larval animals. Grown under both standard laboratory and hatchery conditions they show good profiles of total protein, carbohydrate, and lipid (gross composition), they are rich in essential and non-essential amino acids, and they have significant concentrations of essential polyunsaturated fatty acids. Haptophytes are also rich in B, C, D, and K vitamins. The cells are easily assimilated by larval animals because of their small size (3-8 µ,m) and absence of a tough cell wall. Other attributes include fast growth rates, easy mass-culture, wide temperature and salinity tolerances, and absence of toxins. The nutritional attributes of haptophytes studied in our laboratories will be described in this paper.
Dimethyl sulfide: production and atmospheric consequences
Authors: Malin Gillian , Liss Peter S , Turner Suzanne M
Published: November 2023

The oceans are the major source of a number of volatile organic compounds which enter the atmosphere via air-sea exchange and play a significant role in biogeochemical cycles and global atmospheric chemistry. The focus of this chapter will be one such compound, dimethyl sulfide (DMS; (CH3hS), its biogenic production by haptophytes and possible global effects.
Origin and relationships of Haptophyta
Authors: Cavalier-Smith T
Published: November 2023

Haptophyta are placed, with Heterokonta, Chlorarachniophyta, and Cryptista, in the kingdom Chromista because in all four phyla the chloroplasts are surrounded by a periplastid membrane, located either inside the lumen of the rough endoplasmic reticulum (RER) or ( Chlorarachnion only) inside a smooth endomembrane. This unique arrangement arose abut 600 millions years ago by incorporating a symbiotic eukaryotic alga into a biciliate protozoan host. Ancestral chromists were photophagotrophs, but phagotrophy and photosynthesis were independently lost several times in different diverging lineages. Haptophyta and Heterokonta (i.e. ochristan algae, Pseudofungi, Bicoecia, Labyrinthulea) are grouped as the infrakingdom Chromobiota because they share five derived characters: (1) chloroplasts with thylakoids stacked in threes, and chlorophylls c1, c2, c3, and fucoxanthin, but no phycobilins; (2) chloroplasts located inside the RER and periplastid membrane, but (unlike cryptomonads and Chlorarachnion) with no nucleomorph; (3) an autofluorescent posterior cilium, (4) tubular mitochondrial cristae with intracristal filaments; (5) large body scales. Ultrastructural and molecular evidence favour a single symbiotic origin for all chromists, and a very early divergence between the four phyla. The symbiont was probably intermediate between red algae, green algae, and dinoflagellates, and closely related to their immediate common ancestor, while the host was an opalozoan with tubular surface hairs and probably body scales.
The history of agricultural development a
Authors: Ruf T
Published: November 2023

Anyone travelling today in the Nile Valley and meeting a farmer coming back from his fields with his hoe on his shoulder might think that he is seeing a farmer straight out of Egyptian antiquity; he might well imagine that Egyptian agriculture has not changed since time immemorial. In his defence it must be said that none of the many tourist guides he will consult during his journey will help him to form an opinion. They nearly all present the Egyptian fellah as someone living by traditions and techniques that are a thousand years old. If they are to be believed, nothing has changed in Egypt since the days of Rameses. This myth of the fellah as a direct descendant of the peasant from the land of Among is still so rooted in people’s minds that it must be denounced. There is now practically nothing in common between today’s agriculture and that of antiquity or the Middle Ages. Techniques, crops, agricultural productivity, and even the very landscape have been transformed. These deep-rooted developments in agriculture stem, without any possible doubt, from the ways in which the Nile waters have been used. Whereas for thousands of years farming communities carried out extensive agriculture when the waters were low, today’s farmers irrigate their fields through a very dense system of irrigation canals. Theirs is a very intensive and productive type of agriculture which was still quite unheard of at the start of the nineteenth century.
Systems of agricultural production Middle and Upper Egypt
Authors: Beshai A A
Published: November 2023

It may be that Egypt is now seen as a country which is open to the rest of the world. Its geopolitical situation is well recognized, and Egypt’s role with respect to other Middle Eastern countries and African countries is as significant as her links with Europe. In the last two decades, out-migration of workers with its economic and social implications has become a noticeable feature of the country. Indeed, in recent years, remittances from Egyptians working abroad have often been the largest item of credit on the capital account of the balance of payments. Most of the migrant workers are from Middle and Upper Egypt, defined as the areas covered by the governorates of Giza, Beni Suef, Faiyum, and Minya (Middle Egypt) Asyut, Sohag, Qena, and Aswan (Upper Egypt) (Fig. 14.1).
Physiography, geology, and soils
Authors: Mitchell C W
Published: November 2023

The Sudan forms a part of the extensive, flat, peneplained surface which dominates the whole of north-east Africa. It falls from about 800 m above sea level in the west and south to about 300 m on the Egyptian border and is defined by a ring of uplands. The physiography of the country is shown schematically in Fig. 1.1. In the north-east, the Red Sea Hills, composed of basement granites and metamorphosed sediments, rise to over 2000m. They form a sharply defined escarpment less than 50 km from the coast, which is the drainage divide between the Red Sea and the Nile. The locations of places mentioned in the text are shown in Fig. 1.2.
Agriculture in the national economy
Authors: Gurdon c. G
Published: November 2023

Agriculture plays a pivotal role in the economy, providing a livelihood for over 80 per cent of the population. Its share of the labour force is still over 60 per cent and its share of total exports is over 95 per cent. The country’s efforts to achieve economic progress and transformation are dependent on the performance of the agricultural sector and Sudanese industry is also almost entirely dependent on agriculture as a source of raw materials.
Rural small industries and crafts
Authors: Hansohm D
Published: November 2023

In discussions of socio-economic development, especially in the African context, the actual and potential role of small industries (including crafts) is recognized increasingly. Many governments as well as supra-national organizations give high priority to the promotion of small industries—at least in the plans.
Agricultural marketing and pricing: a synopsis of current problems
Authors: Oesterdiekhoff P
Published: November 2023

The subject of agricultural marketing entered quite late into the discussion on planning and evaluation of development processes and projects. Although this deficiency had already been pointed out in the 1960s (Abbott 1967, p. 393, 1968, pp. 87-92; Jones 1972, pp. 18-19), the empirical research on agricultural markets is still excessively deficient—both in relation to other topics and in view of the political significance of the subject. It may well be that economic research was not prepared to turn towards agricultural marketing as long as the ‘classical’ tenet—that production is what matters (Abbott 1967, p. 393)—was pre-eminent.
National policies for agriculture
Authors: Wohlmuth K
Published: November 2023

The economic crisis which has been affecting the Sudan since 1977/8 is having a particular effect on the agricultural subsectors (irrigated agriculture, mechanized rain-fed farming, traditional rain-fed farming, livestockraising, and forestry) and also on the industrial sector of the country. These subsectors are suffering from the repercussions of the most severe economic crisis since Independence (1956), a crisis which is the result of unfavourable world market trends, over-ambitious development programmes in the 1970s, and a failure of policy reform at the macro- and sectoral-levels in the 1980s. The worsening balance of payments situation, the increasing indebtedness, the failure to come to terms with the International Monetary Fund (IMF), the banks and other donors, the decrease of official transfers from Sudanese workers abroad, the decreasing level of foreign aid, the increasing pressure on the Sudanese pound (£S), and the capital flight go parallel with unfavourable cotton marketing conditions and unstable internal political developments (Sudanow 1987a, b; Ottaway 1987).
Molecular evolution and quasi-species
Authors: Rowe Glenn
Published: November 2023

As our first model of a primitive biochemical system, we will examine a model originally proposed by Manfred Eigen in 1971, and developed further by Eigen in collaboration with Peter Schuster in 1977. The model assumes the existence of molecules of an indeterminate structure which have the ability to replicate themselves without the aid of catalysts. The reader may picture these molecules as DNA, but no details of the structure of the molecules arc assumed or specified in the mathematics.
Stochastic processes
Authors: Rowe Glenn
Published: November 2023

The model of the early stages in the origin of life presented in the last chapter is both deterministic and continuous. Neither of these properties is particularly suitable for a system, such as an evolving molecular soup, which consists of a relatively small number of molecules in random motion. A more realistic model of such a system must take account of both its discreteness and stochasticity.
Artificial life
Authors: Rowe Glenn
Published: November 2023

One of the problems in the study of the origin of life is that we have only one example of a biosystem to study. There may be other examples of life elsewhere in the universe (despite the negative findings of the Viking mission to Mars, scientists have not totally ruled out the possibility of life there) but, discounting some of the more inventive reports of UFOs, the only system available to us for direct study is that of which we arc a part.
The immune system
Authors: Rowe Glenn
Published: November 2023

The immune system is popularly conceived as the body’ s defence system which valiantly fights off attacks from hordes of parasites, such as bacteria and viruses. To a certain extent, this is true, but the immune system is much more than this. It is a complex cellular and molecular system which is capable of recognizing and eliminating virtually any substance which is foreign to the organism in which it resides, while at the same time ignoring cells and molecules produced by its own body. When one considers the enormous variety of molecules in both categories, foreign and ‘ self’, one begins to understand the sophistication of such a biochemical system.
The McCulloch–Pitts neural net
Authors: Rowe Glenn
Published: November 2023

One of the earliest purely theoretical treatments of a neural network was that of Warren McCulloch and Walter Pitts (1943). The original paper is quite forbidding to the modern reader, since it uses the terminology of formal logic, something which is not often taught in undergraduate courses, even those in mathematics. Despite the abstract notation, however, the basic ideas in McCulloch and Pitts’ paper are quite simple. Considering the state of the art when the paper was published (long before the widespread use of computers to which we have become accustomed) its ideas are ahead of its time, and the paper deserves its reputation as one of the classic papers of theoretical biology.
The Golden Age Of Microbiology
Authors: Lax Alistair J
Published: November 2023

The last 25 years of the nineteenth century have been referred to as the ‘golden age of microbiology’. This is no exaggeration. The advances in microbiology at that time exceeded even the great leap in our understanding of bacteria that occurred during the late twentieth century. Infectious disease, not even an accepted concept in 1850, moved from dark religious superstitions to a science. In the process medical microbiology was invented and toxins were discovered. Indeed the latter half of the nineteenth century was a wonderful time for science in general.
A Broader View
Authors: Wilkins Maurice
Published: November 2023

After the Lasker and Nobel awards, and my confidence that the Double Helix was soundly based, I felt freer to look around and consider the wider role of science in human life, and also to enjoy life more broadly, with Patricia and our growing family. With a scientific reputation, financial security and a supportive family, I could make some choices about where to concentrate my efforts in future.
The Meaning of Colour Terms and the Universals of Seeing
Authors: Wierzbicka Anna
Published: November 2023

‘Colour’ is not a universal human concept. It can of course be created in all human societies, just as the concepts ‘television’, ‘computer’, or ‘money’ can, but despite the rapidly increasing contact between human societies there are still many which have neither borrowed nor developed the concept of ‘colour’ (and of course there have been many more such societies in the past).
Outline of Hindi Grammar
Authors: Mcgregor R S
Published: November 2023

This book has a twofold purpose: first to provide a concise presentation of the essential grammar of modern Hindi, with graded exercises, which brings beginners as quickly as possible to the point where they can read modern prose with profit; and secondly, to serve as reference for those consolidating their grasp of the language. It is therefore, of interest to students beginning courses in Hindi and those who have already learned some. People planning to visit India for business of pleasure will also find it useful, as colloquial vocabulary and style receive equally detailed attention as the more formal written style. The material is presented in roman transliteration as well as in the Indian script, so that the beginner can work through the book unimpeded by script problems, while still enjoying the advantage of contact with the script from the outset. Additions to the third edition include a new set of listening and reading exercises and grammatical index. Available for the first time there are two accompanying cassettes containing the complete Hindi text of the original and the new exercises. Revised and updated, available for the first time with accompanying cassettes.