bluuebunny/crossref_metadata_2025_split huggingface dataset:
Classical polyandry: the most puzzling of avian mating systems
Authors: Ligon J David 
Published: November 2023

Abstract
The term polyandry refers to a mating bond between a female and two or more males. Classical polyandry (Oring 1986) is the term used for social-mating systems where (1) a single female mates either sequentially or simultaneously with two or more males during a single breeding season, and (2) males typically form bonds with no more than one female per breeding cycle or per season. A key characteristic of classical polyandry is that each male has its own nest, where it incubates the eggs and later provides care for its (usually) precocial young, most typically with little or no help from the female. In classical polyandry, males not only provide virtually all parental care, females also compete aggressively for mating opportunities. Female-female competition is probably causally related to the reversed sexual dimorphism in body size and often colour seen in such species (e.g. Jehl and Murray 1986).
The Type-Material of Diptera (Insecta) Described by
Authors: Verrall G H , Collin J E , Pont Adrian C 
Published: November 2023

Abstract
G H Verrall and his nephew J E Collin dominated the study of British Diptera (two-winged flies) for a century, and formed what is probably the finest collection of Diptera ever to have been in private hands - it contains a more complete representation of British flies than does the Natural History Museum in London. The collection, now in the Oxford University Museum, is an entomological resource of international standing, as it contains the original material ('types') of the several hundred new species that Verrall and Collin describe. This book is a source-work of information on the Verral-Collin Diptera. For the research worker, it is a catalogue of the 900 species described by Verral and Collin, with an enumeration of the type-specimens located in their collection and in many other museums in Britain, Europe, and North America. For the historian of science, it contains essential historical, bibliographic, and museological information on an important era in British entomology. Appendices include brief biographies of their collecting associates, a classified list of the new species they described, and a list of the British localities at which their new species were found.
Dietary intake and nutritional status
Authors: Galvin Kathleen A , Little Michael A 
Published: November 2023

Abstract
Until the late 1970s, there were virtually no systematic studies of diet and nutrition of African pastoral populations (Little 1980; Wheeler 1980). Some biomedical studies had explored cardiovascular health status of pastoralists within the context of nutrition, but information on dietary intake was based largely on casual observations (Mann et al. 1972; Shaper et al. 1963). Much of this work was founded on the erroneous belief that pastoral groups subsisted almost entirely on milk products and meat, with corre¬ spondingly high fat intakes (Biss et al. 1971; Mann and Shaffer 1966; Shaper and Spencer 1961). After 1980, several comprehensive studies were conducted to assess diets of pastoral populations, including the Sudanese Baggara (Holter 1988), Kenyan Maasai (Nestel 1986), West African Fulani and Tuareg (Benefice et al. 1984; Wagenaar-Brouwer 1985), and Kenyan Turkana (Galvin 1985). Rather than demonstrating uniform diets high in animal products, these studies described remarkable variation in dietary intakes. Variations were observed among ethnic populations; by status within the population; by age, sex, and activities of population members; by season; and by longer-range environmental fluctuations. Based on these studies, the current view of African pastoralists and their dietary patterns is one in which food production and consumption is highly sensitive to the circumstances of their lives, circumstances that include variations in climate, ecology, health, and social and political conditions.
The oil industry, transport, and the environment
Authors: Chase Rodney 
Published: November 2023

Abstract
Mr Rodney Chase is now Chief Executive Officer of British Petroleum (BP) Exploration. When he delivered this lecture, he was the Managing Director responsible for communications, external affairs, and the environment in British Petroleum pie, the company to which he has devoted his entire career. Rodney Chase has exceptional breadth of experience in the oil industry, having held posts within both the Upstream (exploration and production) and the Downstream (refining and marketing) divisions of BP on three continents: Australasia, Europe, and North America. He has served the company in BP Shipping, in Refining and Marketing, in Distribution, in Oil Trading, and in Gas, as well as holding corporate positions in Finance and Strategic Planning. As Chief Executive Offzcer of BP Finance and Group Treasurer, Mr Chase played a key role in the company’s acquisition of The Standard Oil Company and Britoil, as well as in the divestment of BP’s mining interests. Currently, in addition to his responsibilities for exploration, Rodney Chase has Board responsibility for the Western Hemisphere. He is Chairman of the World Business Council for Sustainable Development (WBCSD) and a Member of the UK Advisory Committee on Business and the Environment (ACEE); he also belongs to the UK Round Table on Sustainable Development.
Periglacial terrestrial habitats
Authors: Fogg G E 
Published: November 2023

Abstract
The supply of water, arriving as precipitation, dew, frost, or run-off, is also affected by slope and aspect. Alternation between moist and dry conditions is least severe on horizontal surfaces. In coastal and maritime situations, melt water may trickle over rock surfaces for much of the summer. Crustose or foliose growth will retain water. Mineral nutrients may come in airborne dust, precipitation, run-off or splash, or, from the rock itself. Near bird colonies the nutrient supply may be so copious as to be toxic.
The marine benthic habitat
Authors: Fogg G E 
Published: November 2023

Abstract
Polar land habitats suffer extreme variation of conditions, with desiccation or mechanical damage by wind, unstable substrates, or ice movement, as the usual limiting factors. Shallow inland waters have similar disadvantages. Deeper inland waters afford more stable conditions with steady temperatures and ample water, but tend to be poor in nutrients. Benthic vegetation is frequently the most successful form of life in them. The sea similarly provides stable conditions and temperatures which cannot fall below—2 °C. This is reflected in the circumstance that a majority of polar invertebrates is stenothermal (i.e. unable to survive outside a narrow temperature range), and standing in contrast to the terrestrial organisms such as Nanorchestes (p. 83), which have remarkably wide thermal tolerances. The sea has the additional advantages that there are no solid barriers to transport of nutrients and movement of organisms. On the other hand, mechanical damage by drifting ice can be severe and polar shores usually seem barren, all exposed life down to several metres being battered and scraped off (Fig. 6.1). Icebergs may plough up the seabed down to 300m or more. Nevertheless, benthic life is abundant in polar seas.
The Deep-sea Dimension
Authors: Herring Peter 
Published: November 2023

Abstract
Look out across the ocean on a calm day, from the shore or from the deck of a ship. The vista is daunting in its scale yet innocuous in its features. But beneath this tranquil skin lies a teeming horde of organisms, from the tiniest viruses to the mightiest whales, all of which are continually influenced by the physical features of the seawater within which they move -and by which they are moved. Evolution occurs apace: ‘ Even the most peaceful place is full of strife, with any weakness of its inhabitants at once exploited’ Gones 1999).
Running water habitats
Authors: Giller Paul S , Malmqvist Björn 
Published: November 2023

Abstract
The landscape across which rivers and streams flow is formed through geo¬ morphological and geological processes. Landforms arc built up through sedimentation and geological activity driven by volcanism and continental drift and are eroded by wind, ice, and water. These complex processes together determine the outlines of the catchments within which precipitation falls, flows downhill, and ultimately forms the physical channels of running waters. Rivers arc dynamic systems that are born and age. Ageing involves continuing erosion or the stream channel back towards the source or out onto the floodplain. Erosion is greatest in certain areas (e.g. China, the south-eastern United States) which is shown in the rivers’ particularly heavy silt loads. Typically, river channels have extended lifespans compared to lakes. The world’s really large rivers, along with their great age and diversity, also have many unique organisms and a myriad of ecological processes that have a significant influence over the entire catchment system they drain. Unfortunately, these systems have suffered more than any other from man’s influence, and few remain in a natural, unaffected state.
Evolution, systematics and biogeography of Palaearctic vipers
Authors: Nilson Goran , Andren Claes 
Published: November 2023

Abstract
Very few synapomorphies have been proposed for the ‘Eurasian group ‘ (Vipera s. l., Eristicophis and Pseudocerastes) within the Viperinae. Several studies have demonstrated difficulties in distinguishing the group in cladistic terms. However, different species groups show monophyletic patterns. The different spectra of habitat choice, altitude and latitude distributions, reproductive strategies etc. are analysed, and various phylogenies as well as the evolutionary history of lineages within the group are re-examined.
Growth and survival of Vipera berusin a variable environment
Authors: Forsman Anders 
Published: November 2023

Abstract
Data from a capture-mark-recapture study (1986-1994) of a population of adders Vipera berus inhabiting a group of islands off the Swedish east coast in the Baltic Sea are used to examine whether changing food availability and weather conditions influence growth and survival of large relative to small individuals. Mean air temperature and population density of the field vole Microtus agrestis, the primary prey for adders, were used as measures of weather conditions and food availability, respectively.
The relationship between growth rate and body size varied significantly among years, but was parallel in males and females. Large and small snakes responded differently to changes in vole densities; growth rates decreased at a slower rate with increasing body size when voles were abundant than when voles were scarce. There was no effect of changing weather conditions on adder growth rates.
Logistic regression analyses of recapture data revealed that survival probability of adders increased with increasing body size in some years and decreased with increasing body size in other years. The survival advantage of large body size tended to increase with increasing food availability, but was not affected by changing weather conditions. Within any given year, the relationship between survival and body size was similar in the two sexes.
Years characterized by rapid individual growth rates were associated with a subsequent reduced survival probability of large relative to small snakes, a pattern that should prevent consistent shifts in body size through time. Although an observed lack of variation in mean body size of female adders across years corroborates this prediction, mean body size of male adders increased significantly during the nine years of the study.
Molecular evolution of phospholipase A2s and metalloproteinase/ disintegrins from venoms of vipers
Authors: Moura-Da-Silva Ana M , Theakston R D G , Crampton Julian M 
Published: November 2023

Abstract
The evolutionary relationships of venom toxins have been studied by independently analysing venom group II phospholipases A2 (PLA2s) and mammalian and snake venom metalloproteinase/disintegrin/ cysteine-rich (MDC) families of proteins. Phylogenetic trees grouped both venom group II PLA2s and MDC proteins according to current taxonomic divisions and/or functional activities. Gene duplications may have occurred at different points during the evolution of these protein families. The pattern of variability of the cDNAs coding for venom toxins has also been analysed. The greatest sequence variation of venom group II PLA2s has been observed in the region coding for the mature protein, with most of the substitutions occurring in non-synonymous positions. In MDC proteins, the snake venom metalloproteinase domain appears to be the most variable, whilst neutral selection appears to be responsible for the evolution of the mammalian proteins, the only exception being the region comprising the catalytic site of the mammalian metalloproteinase domain. These data suggest that gene duplication followed by hypervariability of the amino acids in the functional domains and positive selection may have occurred during the evolution of venom toxins, assisting the generation of diversity in these protein families.
Snake venoms are complex mixtures of proteins with different toxic or enzymatic properties. The type of toxic activity of the venoms appears to reflect their taxonomic classification; for example, Elapidae and Hydrophiidae venoms are generally neurotoxic whilst Viperidae venoms are more complex, including a number of enzymes that may induce local tissue damage, haemorrhage and often also coagulopathy (Warrell 1983). In the Viperidae these enzymes generally belong to few gene families. The most important of these, as far as toxicity is concerned, are the proteinases and the phospholipases A2 (PLA2s). Proteinases acting .on different substrates, or PLA2s with different tissue specificity, have often been reported in viper venoms (Kini & Evans 1989; Bjarnson & Fox 1994).
The kinetics of snakebite envenoming and therapy
Authors: Theakston R D G 
Published: November 2023

Abstract
Treatment of systemic envenoming is related to the neutralizing efficacy of the antivenom used, the route by which it is administered and the dose. In the past, treatment of patients has depended almost entirely on the individual clinician ‘s experience in assessing the severity of envenoming. The development of enzyme immunoassay has enabled a more scientific appraisal of the situation, allowing the accurate estimation of circulating specific venom and antivenom levels at any time in the patient ‘s blood and other body fluids. It is therefore possible to measure accurately the efficacy of antivenom in the neutralization and clearance of venom antigen. In Brazil it has been shown that clinicians are treating patients with excessive amounts of highly efficient Bothrops polyspecific antivenom, with a resulting unacceptably high incidence of early anaphylactic reactions and, in Sri Lanka, the use of imported Indian antivenom is relatively ineffective in neutralizing the venoms of Sri Lankan snakes, demonstrating the real problem of venom variability within individual species. For example, Indian Russell ‘s viper venom does not possess the neurotoxin present in the venom of the Sri Lankan subspecies. In West Africa the improved clearance of venom when a monospecific Echis antivenom is used in the treatment of Echis ocellatus envenoming, compared with that of the polyspecific antivenoms currently in use, has been demonstrated. Such clinically-based immunological studies provide an objective assessment of antivenom therapy which has not in the past been feasible. This should result in more efficient and controlledust of expensive antivenoms for treatment of systemic envenoming. Such studies also emphasize the importance of individual countries producing their own antivenoms for treatment of snakebite.
Tinamous
Authors: Davies S J J F , Bamford Michael J , Loomes Danika 
Published: November 2023

Abstract
Ranging in size from 1 S to 50 cm, males and females usually look alike, but the females are slightly larger and often a little more colourful than the males. All are ground-dwelling but capable of flight, resembling quail and partridges, although they are not related. The bill is thin and slightly curved, the head is small and the neck is thin. The rear part of the body seems to be high, owing to the great development of rump feathers; these often hide the very short and soft tail. The thick legs are built for running; there are three short front toes, the hallux being either elevated or absent.
The Quantum Atom
Authors: Bader Richard F W 
Published: November 2023

Abstract
Lewis introduced the concept of the electron pair into chemistry in 1916. In this paper (1916) he was able to rationalize the known geometries of carbon compounds by replacing the prevailing notion of a cubical arrangement of an octet of electrons by a tetrahedral arrangement of four pairs of electrons. What particularly served to later convince Lewis (1933) of the potential of the new quantum mechanics, as evidenced by the opening quotation, was its ability to account for observed molecular geometries and so provide a theoretical basis for his electron pair model. The early development of the valence bond theory of directed valence by Slater (1931) and Pauling (1931, 1960) provided the first quantum mechanical rationalization of molecular geometry. The valence bond approximation to the wave function, as expressed in terms of the overlap of hybridized atomic orbitals to describe the pairing of electrons, coupled with the notion of electron spin, was the natural theoretical extension of the pair concept of Lewis. The hybrid orbitals were spatially localized in directions coincident or nearly coincident with observed molecular geometries and this gave theoretical substance to the notion of picturing a bond as a spatially localized pair qf electrons. Pauling’s emphasis of the use of ionic-covalent resonance structures to account for the differing character of bonded interactions was in turn a restatement of Lewis’s idea to represent the bonding between a pair of atoms in terms of tautomeric extremes of electron-sharing possibilities. It was a principal claim of Lewis’s first paper (1916) that ‘According to the theory which I apply now presenting, it is not necessary to consider the two extreme types of chemical combination, corresponding to the very polar and the very nonpolar compounds, as different in kind, but only as different in degree.’
The representation of space groups: an example
Authors: Altmann Simon L 
Published: November 2023

Abstract
A remarkable property of space groups was discovered in Chapters 5 and 6. If, given a space group G, we obtain bases for all the irreducible representations of its translation subgroup T, then from these bases (which are the Bloch functions), bases of the representations of G can be constructed which have two properties: they are irreducible and they are complete (that is, they span all the irreducible representations of G). This result is of major importance since the bases for the irreducible representations of G in which we are interested are the energy eigenfunctions, but it is a difficult result to prove. We shall provide in this chapter an example which will allow the reader to verify that the method given in Chapters 5 and 6 actually works, and which will help to consolidate some important concepts such as those of stars, small representations, degeneracies and bands. Except insofar as it might be required in order to build up experience in these topics, this chapter will not be necessary for the rest of the book, so that the reader who feels already sufficiently confident about the methods so far developed can proceed straightaway to Chapter 8 and return to the present chapter at any later time.
Bands and Fermi surfaces in metals and semiconductors
Authors: Altmann Simon L 
Published: November 2023

Abstract
Although quantitative methods for the calculation of band structures will not be discussed until Chapter 10, we shall give here a few important examples of their applications, since we already have the tools for understanding these results. This will provide better continuity with the methods so far studied for the description of bands. We shall first consider a semiconductor, silicon, for which at absolute zero the whole of the Brillouin zone is fully occupied. (As it is now standard practice in describing computed bands, the reduced band scheme will be exclusively used for this purpose.) After this, the noble metal copper will be treated and, since the Brillouin zone is only partly occupied here, the Fermi surface will also be discussed. The example of copper will allow us to understand also the qualitative features of the bands in simple metals (like the alkalis) and in transition metals (like nickel).
What porphyrins are and what they do
Authors: Milgrom Lionel R 
Published: November 2023

Abstract
What’s in a name? Names are important because they can tell us what things are, and what they do. Above all, names tell stories. Take the word porphyrin for instance. In a strictly chemical sense, this word has an exact meaning. It is the name given to a family of intensely coloured compounds, at whose heart is a large macrocycle of twenty carbon atoms and four nitrogen atoms. The macrocycle is itself built up from four smaller rings, each made up of four carbon atoms and one nitrogen atom. Each of these rings is joined to its neighbour by one bridging carbon atom So much for the chemical definition. Hidden within it is a vast chunk of history, stretching back to the beginning of civilisation in the Eastern Mediterranean.
…And where porphyrins go to
Authors: Milgrom Lionel R 
Published: November 2023

Abstract
The great science fiction writer Arthur C. Clarke once wrote that behind every living human being stands a hundred million ghosts. It is another way of saying that living things die and replace themselves. But it’s not only living things (right down to the lowliest virus) that turn themselves over. Many of the molecules that control biological activity do the same thing and porphyrins arc a good example of this. Red blood cells live for about three months in the bloodstream, carrying oxygen around the body, before becoming senescent. They are then transported to the liver where they are dismantled. During this process, the heme is broken open to release the iron, which is either excreted or saved depending on the body’s reserves of the metal. After several further transformations, the remains of the heme are excreted from the body.
Intermolecular interactions in the crystals of simple cyclic β-diketoalkanes
Authors: Katrusiak Andrzej 
Published: November 2023

Abstract
The crystal structures of several simple cyclic βdiketoalkanes have been studied at high pressures; they include 1,3-cyclopentanedione (hereinafter CPD), 1,3-cyclohexanedione (CHD) and 2-methyl-1,3 cyclopentanedione (MCPD). In the crystalline state the molecules of these compounds are present in enol form and are linked by short (Table 1) asymmetric and nearly linear hydrogen bonds. Several features are common to these structures: the molecules are hydrogen-bonded into chains, the conjugated π-electron bond system and the enolic hydrogen atom (O=C-C=C-OH) as well as the adjacent atoms form a planar fragment of the molecules, the molecules in one chain are coplanar, the chains of the molecules are arranged in the crystals in such a way that each chain has one neighbouring chain on each side forming sheets of chains.