bluuebunny/crossref_metadata_2025 huggingface dataset:
Algal ‘gardening’ by grazers: a comparison of the ecological effects of territorial fish and limpets
Authors: Branch G M , Harris J M , Parkins C , Bustamante R H , Eekhout S
Published: November 2023

Algal ‘gardening’ by grazers modifies macroalgal assemblages by selectively enhancing particular species and increasing the food value of the algae. Three main groups of grazers are involved: fish, limpets, and a few polychaetes. Gardening shifts algal assemblages towards more productive and/or easily consumed species such as filamentous or finely branched algae and non-coralline crusts. Species richness and biomass of gardens depend on the intensity of grazing in gardens relative to background levels. Grazers potentially influence their gardens by altering grazing intensity (usually by territorial defence), nutrient enhancement, ‘weeding’ or ‘sowing’ selectively, and modifying availability of substratum. Gardening grazers seem ‘prudent’, but this may relate to changes in the productivity, food value, or anti-herbivore defences of the algae in their gardens. Territorial defence of gardens is most intense against competitors, and gardening is likely to be most frequent where algal productivity is low and/or grazing intense, as can be shown by geographical gradients. Thus gardening has both evolutionary and ecological implications.
Bioerosion and biogeomorphology
Authors: Spencer T
Published: November 2023

Bioerosion is a complex set of physical and chemical processes of rock removal, driven by the interrelationships between (1) ‘biological corrosion’, a solutional process (accounting for 10-30 per cent of total erosion) largely engineered by Cyanobacteria, and (2) ‘biological abrasion’, the removal of these micro-organisms and particulate debris, notably by boring sponges and bivalve molluscs, burrowing echinoids, and grazing amphineurids and gastropods (70-90 per cent of total erosion). Rates of biological abrasion, although largely derived from either live coral surfaces or unconsolidated reef sediments and thus not readily transferable to lithified substrates, have been established through studies of in situ surface modification, experimentation with block transplants and through the collection of sedimentary products. Mean rates of general surface-lowering characteristically range between 0-5-1-0 mm yr-1. As cyanobacterial zonation, and thus erosion rate, varies with position on the littoral profile, and as this zonation changes with exposure, it is possible to explain the characteristic notched form to the littoral profile and its evolution on rocky shores. However, bioerosion rates do not necessarily increase on progressively higher energy coasts: under microtidal regimes, encrustations of coralline algae and vermetid gastropods on surf platforms act as protective structures, sealing the underlying bedrock from bioerosional processes.
Anxiogenic-like effect of CCK-8 micro-injected into the dorsal periaqueductal grey of rats in the elevated plus maze
Authors: Guimaraes F S , Russo A S , Aguiar J C , Ballejo G , Graeff F G
Published: November 2023

Experiments involving electrical stimulation of subcortical regions of the brain have established that interconnected structures comprising the dorsal periaqueductal grey (DPAG) of the mid-brain, the medial hypothalamus, and parts of the amygdala constitute an important neural substrate for the expression of defensive/aversive behaviour and the associated neurovegetative and neuroendocrine changes (Graeff 1989). These brain structures are also responsible for the development of aversive motivational states, and thus constitute the so called behavioural aversive system (BAS) (Graeff 1989).The neuropharmacology of the BAS, particularly the DPAG, has been systematically investigated using intracerebral micro-injection of drugs often coupled with brain electrical stimulation. The results obtained so far indicate that many neurotransmitters, including γ-aminobutyrate (GABA), endogenous opioids, 5-hydroxytryptamine (5-HT), excitatory amino acids, and acetylcholine, are involved in the modulation of aversive states in the DPAG (Graeff 1984, 1987, 1989, 1991; Schmitt et al. 1984, 1986; Graeff et al. 1986; Carobrez 1987). Anxiolytic drugs such as benzodiazepines, barbiturates, and ethanol, as well as the 5-HT re-uptake inhibitors fluvoxamine and zimelidine, share the property of attenuating aversion due to DPAG stimulation, which suggests that this structure is involved in pathophysiological processes, particularly pain, depression, and anxiety (Graeff 1984, 1989, 1991; Jenck et al. 1989). Interestingly, it has been shown in patients undergoing neurosurgery that electrical stimulation of the DPAG elicits symptoms and autonomic changes that closely resemble a panic attack (Nashold et al. 1974).
CCK as a putative satiety factor in farm animals
Authors: Baldwin B A
Published: November 2023

In addition to the very extensive work using rats as experimental animals (see Chapter 17 of this volume), the function of CCK as a putative satiety factor has been studied in three farm animals - sheep, pigs, and chickens. From a comparative mammalian viewpoint the choice of sheep and pigs is fortunate, since the sheep is a typical ruminant with a complex digestive system and, under natural conditions, a grazing mode of nutrition, while the pig is a representative omnivore with a monogastric digestive system. Pigs, particularly the miniature breeds, are increasingly being used as experimental animals in biomedical research (Pond and Houpt 1978; Tumbleson 1986). The role of neuropeptides in the regulation of food intake is well established (Baldwin 1988), and in this chapter the evidence for CCK as a putative satiety factor in pigs, sheep, and chickens will be examined.
CCK-5-HT interactions influence meal size in the free-feeding rat
Authors: Clifton Peter G , Cooper Steven J
Published: November 2023

Food intake in most mammals is behaviourally complex. In the rat larger amounts are eaten at the beginning and end of the night with relatively lower consumption during the day. In addition, food is consumed in ‘meals’- periods of relatively intense feeding behaviour occupying 2-5 per cent of the animal’s time budget. Changes in food intake may be achieved by modulating meal size, meal frequency, or some combination of both together with readjustment of the usual diurnal intake pattern. The analysis of pharmacologically induced changes in food intake has become widely used in recent years (Clifton 1987).Chronic meal-contingent infusion of CCK substantially and permanently reduces meal size, although meal frequency increases so that the total food intake is only slightly reduced for the first 2 or 3 days and subsequently is no different from control levels (West et al. 1984). The indirect serotonin agonist DL-fenfluramine also reduces food intak , primarily by reducing meal size (Popplewell et al. 1981). As tolerance to the anorectic effect of fenfluramine develops and overall food intake increases, meal size remains reduced and meal frequency increases (Barnfield and Clifton, unpublished data). In both cases the reduction in meal size has been taken as evidence of an effect on satiety rather than hunger.Recent evidence suggests possible interactions between CCK and 5-hydroxytryptamine (5-HT) in the control of feeding. Stallone et al. (1989) have shown that the 5-HT antagonist metergoline blocks the anorectic action of CCK-8 in short-term intake tests. They favoured a central site for this interaction in which the antagonist blocked a vagally transmitted peripheral CCK signal. Cooper _et al. (1990) have demonstrated a rather different interaction. They showed that the CCK antagonist devazepide, at a dose which when given alone had little effect on intake, could block the. anorectic effect of o-fenfluramine. Their study also used a simple short-term intake test. Here we report a meal pattern study in which the same drug interaction is examined.
CCK, gastric emptying, and satiety in man
Authors: Robinson P H
Published: November 2023

In primates, gastric emptying is subject to tight physiological control. In human subjects, emptying of liquids, for example, is slowed by an increase in the caloric content, acidity, or tonicity of the meal (Hunt and Knox 1962; Hunt and Stubbs 1975; Brener et al. 1983), and by the presence of nutrient in the jejunum (Vidon et al. 1989). Liquid meals of fat, protein, and most carbohydrates empty from the stomach of the rhesus monkey at a constant linear rate of calories (McHugh and Moran 1979), while emptying of saline solutions, which proceeds exponentially, is retarded by the infusion of calories into the duodenum (McHugh et al. 1982). The presence of a regulated system of control over gastric emptying provides a possible mechanism for caloric control of food intake, as meals of higher caloric density are emptied from the stomach more slowly and therefore provide a more persistent inhibitory influence on feeding (Hunt 1980). If control of gastric emptying can be shown to be an important influence in determining the onset of satiety and of meal size, then the mechanism by which emptying is controlled comes under scrutiny as a possible mediator of satiety. Several candidates exist, and, because of its known satiety and gastric inhibitory actions, CCK may be a physiological control of gastric emptying and hence of satiety and feeding. In some morbid states, gastric emptying and satiety are both abnormal, and changes in CCK function might provide the pathophysiological basis for the observed behavioural and functional disturbances. In this chapter we shall consider CCK in relation to the role of gastric slowing in the modulation of food intake by nutrients and anorectic drugs in normal primates, including man, and in disorders of eating and weight, namely anorexia nervosa, bulimia nervosa, and morbid obesity.
c-fos mRNA in oxytocin neurons: selective induction by CCK
Authors: Hamamura Mitsuko , Leng Gareth , Emson Piers C , Kiyama Hiroshi
Published: November 2023

The magnocellular neurosecretory system of the rat hypothalamus has long been considered to be an excellent model for the study of mammalian peptidergic neurons. The magnocellular neurons are confined to relatively homogenous nuclei within the hypothalamus- the supra-optic nucleus (SON) and the paraventricular nucleus (PVN)- and the neuronal cell bodies are separated anatomically from the nerve terminals that are present at the site of neurosecretion in the neural lobe of the pituitary (Sofroniew 1983). The outputs of these neurons are the hormones oxytocin and vasopressin, the concentrations of which are readily measurable in the systemic circulation; hence the state of activation of these neuronal pools can be readily assessed in vivo as well as in vitro. As with all neurons, the secretory activity of magnocellular neurons is governed from minute to minute largely by synaptic events at the cell bodies. However, it is now clear that trans-synaptic activation of neurons also elicits longer-term responses that are correlated with, and may be dependent upon, the induction of new patterns of gene expression. Peptide gene expression in neurons can be modulated by many factors, including membrane electrical activity, neurotrophic growth factors, steroids, and neurotransmitters (e.g. Lightman and Young 1987). One of the most important regulators of peptide gene expression appears to be the proto-oncogene c-fos (Morgan and Curran 1989). c-fos messenger RNA (mRNA) and its proteins are expressed in neurons in vitro following intense depolarization induced by high potassium concentrations (Morgan and Curran 1986) and also following applications of nerve growth factor (Curran and Morgan 1985; Greenberg et al. 1985), nicotine (Greenberg et al. 1986), barium (Curran and Morgan 1986), and BayK8644 (Morgan and Curran 1986). The c-fos gene is activated rapidly and transiently, and such so-called immediate early genes have been proposed to encode regulatory proteins that control the expression of late onset genes, including peptide genes (Sonnenberg et al. 1989). In particular, c-fos protein forms a heterodimeric transcription factor complex with c-jun protein, which is the product of a second immediate early gene, and this heterodimer binds with high affinity and specificity to the AP-1 binding site for transcription factor activity on DNA (Rauscher et al. 1988).
CCK-dopamine interactions: implications for treatment of schizophrenia
Authors: Rupniak N M J
Published: November 2023

There has been great interest in the possible role of CCK in the pathophysiology and therapy of diseases in which an abnormality of cerebral dopamine function is implicated. Most attention has focused on schizophrenia as a target for novel drug development. In this chapter I shall collate evidence from studies in animals and man to assess the ways in which the CCK system might be manipulated by novel drugs to treat psychosis and neuroleptic-induced movement disorders.There has been speculation that the intimately shared mesolimbic peptidemonoamine pathway might be selectively manipulated to develop a novel antipsychotic therapy. Indeed, the ability of neuroleptic drugs to alter mesolimbic CCK function selectively may contribute to the way in which these agents exert antipsychotic activity.
The role of CCKA and CCKB receptors in mediating the inhibitory effect of CCK on opioid analgesia
Authors: Dourish Colin T
Published: November 2023

Since the publication of the seminal finding that CCK octapeptide sulphated (CCK-8S) (in this chapter the abbreviation CCK refers to this fragment unless stated otherwise) can block opioid analgesia (Itoh et al. 1982; Faris et al. 1983) there has been considerable interest in the possibility that it may act as an endogenous opioid antagonist (Faris 1985; Han et al. 1985). There was already substantial evidence prior to this discovery that the physiological effects of CCK and opioids were often the antithesis of each other. For example, opioids increase food intake whereas CCK decreases feeding (see Chapter 17 of this volume), and CCK decreases locomotion whereas morphine increases motor activity (Fog 1970; Chapter 22 of this volume). Nevertheless, the discovery of a possible interaction between the two peptides in the control of nociception was of particular significance given the pre-eminence of opioid drugs as painkillers. Indeed, the widespread use of opioid analgesics suggests that examination of CCK-opioid interactions may be of considerable clinical relevance. The potential for CCK-opioid interactions is emphasized by the parailel distribution of the two peptide families and their receptors in the brain and spinal cord. Thus there are high concentrations of CCK and opioids and of CCK and opioid receptors in periaqueductal grey (PAG), ventromedial thalamus, and spinal dorsal horn, all of which are areas that play an important role in the processing of nociceptive impulses (Baber et al. 1989). In addition, there is evidence that CCK and opioids are colocalized in nociceptive neurons in the thalamus and brainstem (Gall et al. 1987). This chapter reviews the preclinical and limited clinical evidence for CCK-opioid interactions in nociception. Particular emphasis is placed on the results of recent studies with potent and selective CCK antagonists which provide strong evidence for a role of endogenous CCK in mediating opioid analgesia in both rodents and primates. In addition, the respective roles of CCKA and CCK8 receptor subtypes (Moran et al. 1986; Dourish and Hill 1987;
Enhancement of opiate analgesia by devazepide in a baboon dolorimetry model
Authors: Klein Hilton , Jackson Robert , McCormick Gwendolyn , Montgomery Tamara , Frankenfield Dale , Pouch Walter , Soper Keith , Murray Kathy
Published: November 2023

Electrical stimulation of tooth pulp provides a means of evaluating the effects of analgesics on pain without the complicating factors associated with peripheral stimulation. It is generally accepted that tooth pulp stimulation primarily elicits pain sensation (Scorr 1972; Anderson et al. 1973; Matthews and Searle 1976; Matthews 1979; Sessle 1979). Because the impulses from the dental nerve enter the brainstem and medulla via the trigeminal nerve, the afferent conduction pathway is short and less likely to be modulated by inhibitory neurons of reflex arcs. It has also been shown that all species have essentially the same dental sensory mechanisms (Byers et al. 1982). These facts make dental nerve stimulation an ideal means of evaluating the central modulation of analgesia as well as providing a procedure in which the basic mechanism of pain remains consistent between the different species. Dental dolorimetry is the measurement of pain responses by stimulation of the tooth pulp nerves and has been used to study pain in the rat (lriki and Toda 1980a, b; Foong et al. 1982a), rabbit (Foong et al. 1982b; Wynn et al. 1984), cat (Mahon and Anderson 1970; Miyagawa et al. 1980), dog (Skingle and Tyers 1980), horse (Brunson and Majors 1987; Brunson et al. 1987), monkey (Van Hassle et al. 1972; Ha et al. 1978; Biedenbach et al. 1979; Chudler et al. 1986), and man (Matthews and Searle 1976). It provides an ideal means of studying pain perception because it is sensitive, reproducible, and allows for the quantitative evaluation of the response to pain with minimal interference from reflex responses. Dental dolorimetry also
ELF magnetic fields and promotion of cancer: experimental studies
Authors: Adey W Ross
Published: November 2023

Major advances in medical science, particularly in the development of antibiotics and chemotherapeutic methods, have sharply r:educed the role of infectious diseases as a prime cause of death in infancy and childhood. Many more people now live to old age, when cancer may cause a significant mortality. At the same time, the persisting and significant incidence of juvenile cancer invites careful consideration of the possible separate or joint roles of environmental factors.
Collective properties of cell membranes
Authors: Adey W Ross
Published: November 2023

In cellular aggregates that form tissues of higher animals, cells are separated by narrow fluid channels that take on special importance in signalling from cell to cell. These channels act as windows on the electrochemical world surrounding each cell. Hormones, antibodies, neurotransmitters, and chemical cancer promoters, for example, move along them to reach binding sites on cell membrane receptors. These narrow, fluid ‘gutters’, typically not more than 150 Å wide, are also preferred pathways for intrinsic and environmental electromagnetic (EM) fields in tissue, since they offer a much lower electrical impedance than cell membranes.
Effect of low-frequency magnetic fields on the chromosomal level in human amniotic cells
Authors: Nordenson Ingrid , Mild Kjell Hansson , Sandstrom, Monica , Mattsson Mats-Olof
Published: November 2023

An increasing number of recent investigations show that weak electromagnetic fields are able to affect biological systems. There are reports from practically all levels of organization, including effects on subcellular levels upwards to man. Several studies show that fundamental processes, such as DNA synthesis, can be influenced by exposure to magnetic fields (Liboff et al. 1984); certain characteristic cell-surface properties change after exposure to weak electric as well as magnetic fields (Marron et al. 1988); chromosomal aberrations have been observed after magnetic field exposure (Nordenson and Hansson Mild 1987). Embryonal development of the chick, mouse, and rat embryos have, in several investigations, been shown to be sensitive towards weak alternating magnetic fields (Berman et al. 1990; Juutilainen 1989). An increased frequency of malformations, as well as early retarded embryos, has also been observed (Frolen et al. 1987; Tribukait et al. 1987; Frolen and Svedenstal 1988). Behavioural changes among experimental animals have been recorded after a combined exposure to static and alternating magnetic fields (Kavaliers and Ossenkopp 1988). Synergistic effects of drugs and exposure to magnetic fields are also reported. Volunteers exposed t weak 60 Hz magnetic fields exhibited a decrease in heart rate (5-10 beats per min) in conjunction with exposure, the change being most prominent during intermittent exposure (Graham et al. 1988). In addition, epidemiological studies indicating that magnetic fields with a field strength exceeding 0.2-0.3 µT are able to act as cancer promoters, have been published (recently reviewed by Ahlborn 1988). There are also reports stating that exposure to magnetic fields from electric blankets, electrically heated water-beds, and electrical floor-heating, causes disturbancies of pregnancies (Wertheimer and Leeper 1989).
Diatom motility: replication study in search of cyclotron resonance effects
Authors: Saalman Elisabeth , Galt Sheila , Hamnerius, Yngve , Norden Bengt
Published: November 2023

This paper presents the results of an experiment designed to replicate the findings of Smith et al. (1987) which implicate a cyclotron resonance effect on a supposed calcium-dependent motility of the diatom Amphora cof¬ feaeformis. This diatom has been reported to have a calcium concentration threshold above which it is motile, with the motility threshold reducible by the application of a.c. and d.c. magnetic fields at cyclotron resonance conditions for calcium. The phenomenon is described in two additional papers from the same research group (McLeod etal. 1987a, b).
Insects and phytochemicals–nature’s economy
Authors: Schoonhoven L M
Published: November 2023

Terrestrial plant life, though restricted to less than one third of the Earth’s surface, absorbs more than twice as much solar energy as aquatic plant life. As a result terrestrial plants transformed what was once a forbidding desert planet, indistinguishable from Mars, into a luxuriant garden, in which insects, birds, and mammals could flourish. Although its uniform green hue suggests a basic homogeneity of the living plant world, its external appearance hides a wealth of chemicals. The variety of these phytochemicals is larger than chemists even in the near past could imagine and remains difficult to appreciate. Upon this seemingly endless number of organic compounds, which are constantly being trans formed and replenished, many herbivores and parasitic organisms thrive and enrich the living world with their presence. The animal kingdom, in size and shape just as diverse as the plant world, includes many herbivores, ranging from plant lice to elephants. Among the herbivores insects occupy a paramount position, as exemplified by their biomass. Total body weight of social insects alone in tropical rainforests is seven times that of vertebrates (Fig. 1.1) (Holden 1989). However, biomass is not a representative trait for their role in a biotic community, because turn over rates, which include feeding, growth, reproduction and decay, are in insects much higher than in vertebrates. Therefore their role in the dynamics of energy and nutrient cycles is much greater than their tiny sizes would suggest. It is estimated that roughly 10 per cent of plant primary production in natural ecosystems is consumed by insects. (In cultivated plants the losses are, despite intense pest control measures, higher and under western conditions amount to 13 per cent.) Actually, in view of the fact that herbivorous insects generally possess short generation cycles, high reproductive rates, and, by being winged, can easily exploit new food sources, it is surprising that, despite the omnipresence of green plants, insects under natural conditions rarely become a threat to the survival of a given plant species.
The chemistry of azadirachtin and other insecticidal constituents of Meliaceae
Authors: Kraus W , Bokel M , Schwinger M , Vogler B , Soellner R , Wendisch D , Steffens R , Wachendorff U
Published: November 2023

The insecticidal properties of extracts of Meliaceae plants have been known in Europe for a long time. As early as 1877 a ‘Synopsis on plants’ was published (Leunis 1877) in which under the heading Melia azedarach is mentioned ‘the leaves kill insects’. This statement was ignored for decades, and investigation into the active principles only started in the middle of the twentieth century (see Kraus 1984, 1986; Taylor 1984; Kraus et al. 1987a). Here, some of our earlier and more recent work on constituents of the following Meliaceae species, which show insect antifeedant and/or insect growth regulation activity, is discussed:
Cyanogenesis and foodplants
Authors: Nahrstedt Adolf
Published: November 2023

Plants constitute a considerable proportion of the human daily diet, with most foodplants providing non-toxic carbohydrates, proteins, or fats; others contain more or less toxic constituents which belong to the so-called secondary metabolites. One class of potentially toxic constituents are the cyanogenic glycosides. Several reviews already exist on their structure variation and distribution in the plant kingdom (Nahrstedt 1992; Seigler 1992) and in insects (Nahrstedt 1988); on their biology (Nahrstedt 1987), biochemistry and metabolism (Conn 1991), and toxicity (Conn 1979; Montgomery 1979; Oke 1980); and on their occurrence in and significance for foodplants of man and animals (Oke 1979; Nartey 1981; Poulton 1983, 1988a, 1990). Reviews concerning isolation and structure elucidation (Nahrstedt 1981; Seigler and Brinker, 1992) as well as liberation, detection, and quantification of hydrogen cyanide as the most important product of degradation have been published (Nahrstedt et al. 1981; Brinker and Seigler 1989).
Recent advances in the production of aroma compounds in plant culture systems
Authors: Charlwood Barry V
Published: November 2023

Higher plants accumulate a wide variety of aroma compounds including the aliphatic straight-chain hydrocarbons and aldehydes (typically found in flowers and fruits), the highly odoriferous derivatives of benzoic acid and phenylpropane (characteristic especially of the Umbelliferae), and a range of nitrogen and sulphur containing volatiles. However, the ubiquitous lower isoprenoids (the mono- and the sesqui-terpenoids) form by far the largest group of natural aromas and a great deal of information has been amassed concerning the role of these secondary compounds in planta. This review will be restricted to a consideration of the recent advances in the biology and biochemistry of the production of lower isoprenoids (especially the monoterpenoids) in cell, organ, and tissue cultures of higher plants.
Proales werneckii: a gall-causing rotifer
Authors: Spooner B M
Published: November 2023

Proales Wemeckii (Ehrenberg) is unique amongst known rotifers in being a gall causer. It is parasitic in species of Vaucheria and Dichotomosiphon, causing characteristic lateral galls on the filaments. It appears also to be unique in being the only non-fungal causer of galls in freshwater algae. The species has other unusual features, notably the presence of males which possess fully developed jaws and a functional mastax, a situation which is of very rare occurrence amongst rotifers. Galls on Vaucheria have been known since early in the nineteenth century and the causer was described in 1834. It has proved to be widely distributed in temperate regions, occurring in both northern and southern hemispheres and is now known to parasitize at least 16 host species. However, P. wemeckii is still infrequently recorded and the process of gall formation remains little studied. A review of our current knowledge is presented here.
Thrips and gall induction: a search for patterns
Authors: Mound Laurence A
Published: November 2023

Thrips suck the contents of individual cells one at a time, and in some plants the surrounding cells react by redeveloping meristematic characteristics leading to gall production. Plant reactions vary in their degree of complexity, from simple leaf curling and distortion to complex multicellular structures of regular form. These galls, however, are wound responses; cell division ceases if the thrips are removed. This ability, to produce new cells and, hence, galls in response to feeding by thrips on young tissue, has arisen in a wide range of unrelated plants. The thrips which induce these reactions in plants come from three widely separated phylctic lineages in the major subfamily, Phlaeothripinae, although most occur in a range of genera in the leaf-feeding Liothrips lineage. The ecological and behavioural relationships between thrips within any one gall, both intra- and interspecific, have not been well-studied. Many leaf-roll galls are probably induced by the feeding activity of (more than one) conspecific individuals; on some plants in India, gall induction may involve feeding by two or more thrips species, while in Australia, some galls on Acacia phyllodes are induced by single individuals who then actively protect their investment.
A willow gall from the galler’s point of view
Authors: Higton R N , Mabberley D J
Published: November 2023

Investigations into gall induction in the leaves of Salix fragilis var. russelliana by Pontania proxima has demonstrated the following. 1 Methods of rearing both insect and host have resulted in an extension of the insect’s flight period from 5 to 8 months, with three broods per year instead of the usual two.
The ecology of the pea galls of Cynips divisa
Authors: Gilbert Francis , Astbury Charlotte , Bedingfield Jenny , Ennis Bruce , Lawson Samantha , Sitch Tracey
Published: November 2023

The results of a long-term study into the population ecology of pea galls is presented. Pea galls are produced by the agamic generation of the cynipid gall wasp Cynips divisa Hartig and they were studied over the period 1985-1991. Population biology is the sum effect of variations in fitness between individuals, variations which are determined by life history parameters. Components of fitness were measured for a large sample, calculating survival, size, fecundity, and maturity at eclosion: the fitness consequences of ovipositional decisions made in positioning the gall on different trees, leaves, and positions within leaves are analysed. Evidence for a 6-7 year population cycle is discussed.
Shaman as scientist: indigenous knowledge systems in pharmacological research and conservation
Authors: Cox P A
Published: November 2023

Indigenous knowledge systems have historically benefited pharmacological research programmes. If properly utilized, indigenous knowledge systems promise to assist in the future discovery of new drugs. The ethnobotanical approach to drug discovery combines two components: analysis of indigenous knowledge concerning medicinal plants, and bioassay-guided evaluation of plants used medicinally by indigenous peoples. Successful programmes of ethnobotanical drug discovery have optimized both aspects. Yet despite demonstrable historical success in drug discovery, there has been considerable resistance to incorporation of information derived from indigenous knowledge systems into modern programmes of drug discovery. This chapter examines the sometimes hostile interaction between western and indigenous cultures, yet suggests that many indigenous practices, including ethnopharmacology, fit well within current paradigms of science. Strategies for optimizing the input of indigenous knowledge systems into western drug discovery programmes are sketched. The reciprocal responsibilities of western investigators to indigenous practitioners and healers who participate in their research programmes are outlined.
New biologically active metabolites from plants used in Papua New Guinea and Bolivia
Authors: sticher O
Published: November 2023

Papua New Guinea and Bolivia are countries having wide areas of tropical rainforest which is important as a source of traditional medicines. Traditional healing methods are widespread in both countries since the medical system is underdeveloped. Many people still have a broad knowledge about the folklore uses of plants and plant-derived preparations. This knowledge may vanish in the near future because of the disappearance of indigenous cultures, the migration from the country to the towns, and the destruction of the rainforests. Hence the largest natural resource for medicinal plants will also disappear.
Bioactive polymers from higher plants
Authors: Wagner H , Gerhauser C , Samtleben R
Published: November 2023

With the exception of enzymes and starches, polymers from higher plants have received little attention by chemists, biochemists, or pharmacists. This is astonishing in view of the wide use of water extracts of plant drugs in ancient times. The main reason for this lack of interest has been a shortage in highly selective tools to isolate these highly polymeric compounds in a pure form and the difficulty in structural determination. Furthermore, bioassays which could be used for systematic screening were not available until recently. Since all these shortcomings have now been overcome there is increasing interest in plant-derived polymers.
Structure and biological activity of sesquiterpene and diterpene derivatives from medicinal plants
Authors: Aquino R , De Simone F , De Tommasi N , Piacente S , Pizza C
Published: November 2023

Medicinal plants represent an almost unexplored reservoir of new substances with potentially useful properties. Compounds from higher plants are of great potential value as medicines, as well as starting points for synthetic analogues and industrial raw materials. Plant metabolites can also be used to establish taxonomic relationships among plants and may help for a better understanding of certain biological processes.
Active acquisition, of de11tli information by Honey-bees
Authors: Lehrer Miriam
Published: November 2023

Until quite recently, the only motion--induced behaviour investigated in the bee was the optomotor response (reviewed by Kaiser 1975). This reflex-like behaviour, common to all insects, consists of the animal’s yaw, roll., or pitch 1·esponse to large-field motion in its visual surroundings.
Energetics and the evolution of body size in small terrestrial mammals
Authors: speakman J R
Published: November 2023

Many species of very small terrestrial mammals exhibit clinal patterns in their body size, often with larger individuals predominating in populations from higher latitudes (Berg mann’s law). Classically, this pattern has been explained as reflecting the advantageous surface-to-volume ratio of larger animals, which provides them with a thermoregulatory advantage in colder regions, because it reduces their energy demands. Attempts to expand on this energetics explanation are, however, fraught with difficulty. A major problem relates to the fact that it is not possible to speculate on the direction of selection on body size by considering costs alone. However, when both costs and gains are considered there is a range of potential effects, which depend critically on the interspecific scaling relationships of energy gains and energy costs. Since these traits may vary in time, in space, and across species, general predictions from the energetics hypothesis of the direction of selection on body size are therefore not possible, and a wide range of directional effects of latitude on size is therefore predicted (and observed). It is generally the case that, within a species, mass explains less than 50% of the individual variation in metabolic energy expenditure. This low explained variation raises the question of why some individuals sustain high rates of metabolism, when this would be likely to make them more susceptible to failure in achieving an energy balance. In wood mice, Apodemus sylvaticus, we have found a correlation between basal metabolic rate (BMR) and the thermogenic capacity (noradrena line-induced metabolic rate).
Does echolocation constrain the evolution of body size in bats?
Authors: Jones Gareth
Published: November 2023

Most bats weigh less than 10 g. Megachiropterans are considerably heavier than microchiropterans, possibly because of their different ancestry or because they do not use laryngeal sonar. The predominance of medium-sized to small species of bats is compatible with general theories of extinction and speciation rates in relation to body size. There are few obvious links between diet and body size. It is more likely that biophysical factors associated with flight and/or echolocation constrain body size in bats. Models of flight power predict that flying vertebrates could weigh up to 12 kg, but the largest bat weighs under 1.5 kg. Bats radiated to fill the niche of nocturnal aerial insectivores, and echolocation is an effective way of detecting insects in the dark. However, high frequencies must be used to give strong echoes from small targets. Call frequency scales negatively with mass in five families of bats. Bats must probably be small to produce ultrasound. Because larger echolocating bats call at lower frequencies (hence long wavelengths), it has been proposed that they may not be able to detect small insects effectively. Large bats might therefore have a narrow dietary niche, and the need to rely on large, scarce prey would not favour the evolution of large size. However, large bats in fact seem to have broader dietary niche breadths than smaller species. Flapping and calling are coupled in echolocating bats as an energy-saving mechanism. Wingbeat frequency decreases as body size increases and aerial insectivorous bats generally emit one or fewer pulses per wingbeat. Aerial insectivorous bats may therefore be prevented from evolving large size because they would not be able to produce echolocation calls at a rate high enough to catch sufficient insects to meet the energetic demands associated with being large.
Dwarfing in island elephants and deer: processes in relation to time of isolation
Authors: Lister A M
Published: November 2023

Dwarfed populations of large mammal species evolved on many islands in the Pleistocene. Recent discoveries and advances in dating allow us to take the first steps in observing the time scale of dwarfing and the stages by which size reduction and associated morphological changes occurred. Dwarfed red deer on Jersey, and dwarfed woolly mammoths on Wrangel Island, evolved in a few thousand years or less. Their diminution probably occurred by an interplay of ecophenotypic and genetic effects, and was associated with some changes in proportion and morphology. These can be attributed to direct allometric and develop mental effects of size reduction, and may in some cases have been adaptively suboptimal. By comparison, dwarfed deer from Crete, elephants on other Mediterranean islands, and Columbian mammoths from islands off California, had probably been isolated for at least an order of magnitude longer than the Jersey and Wrangel animals. In consequence, they show modifications of cranial, dental, and limb morphology which can be interpreted as adaptive to small body size or the island habitat. Other proportions have readjusted to counter the initial developmental effects of dwarfing. Some forms evolved unique display organs implying biological speciation. In several cases, the morphology appears paedomorphic relative to the full-sized ancestor.
Molecular Interactions Of Phenolic Compounds In Relation To The Colour Of Fruit And Vegetables
Authors: Brouillard Raymond , Figueiredo Paulo , Elhabiri Mourad , Dangles Olivier
Published: November 2023

Three large families of pigments give colour to plants: chlorophylls, carotenoids and flavonoids (Britton, 1983). The two latter are seen by humans on the green background provided by the chlorophylls. Carotenoids and flavonoids are widespread in fruit, flower and vegetable tissues. Flavonoids belong to a larger group of natural organic plant compounds, the polyphenols. Good recent introductions to the biochemistry of polyphenols may be found in Scalbert (1993) and in Brouillardet al.(1995).
Astringency
Authors: Clifford Michael N
Published: November 2023

The ASTM Committee E-18 on Sensory Evaluation has defined astringency as ‘the complex of sensations due to shrinking, drawing or puckering of the epithelium as a result of exposure to substances such as alums or tannins’ (ASTM, 1989). TheShorter Oxford English Dictionarydefines ‘astringent’ as ‘having the power to draw together the organic tissues; binding, constrictive, styptic’ (SOED, 1944). Two important, possibly crucial, features of astringency which are not immediately apparent from the foregoing definitions, but which are well-known to all who have encountered it in the mouth, are its lingering nature and tendency to become more pronounced on repeated exposure (on a relatively short time scale such as the repeated sipping of wine).
The psychology of food choice: the influence of attitudes and flavour perception
Authors: Shepherd Richard
Published: November 2023

The choice of foods by free-living people is a research issue of concern for many of those involved in the production and distribution of foods, and also for those concerned with nutrition and health education. Despite a great deal of knowledge gained on the impacts of diet on health and on specific diseases (Committee on Medical Aspects of Food Policy, 1994), relatively little is known about why people choose the foods that make up their diets or about how their choices might be influenced. Given recommendations, for example, to reduce fat in the diet or to increase the consumption of fruit and vegetables, it is then necessary to understand the determinants of food choice and what obstacles there might be to such changes. Although official recommendations have been in place in the UK since the report by COMA in 1984 (Committee on Medical Aspects of Food Policy, 1984) for a reduction in the energy in the diet derived from fat there has been relatively little change (Committee on Medical Aspects of Food Policy, 1994).
Coumarins in fruit and vegetables
Authors: Zobel Alicja M
Published: November 2023

Coumarins (benzopyrones) are very common secondary metabolites that have been found in all botanical families investigated. Some products of coumarins are even found in animals, as in the case of beaver scent glands, which contain anabolites of ellagic acid (Dean, 1963). Since the beginning of the 19th century, when Vogel (1820) reported isolation of coumarin, until 1991, about 1500 coumarins had been identified (Murrayet al.,1982; Murray, 1991), at the rate of about 20 per year. The term coumarin is derived fromCoumarouna odorataAubl. (Guillemette, 1835), the name of the tonka bean tree, from which coumarin was first isolated. The structure of coumarin was independently elucidated about 50 years later independently by Fittig (1868) and Strecker (1868).
ACC oxidase gene family: characterization and down-regulation by genetic manipulation
Authors: Bouzayen M , Ferrer M , Guillen P , Ayub R , Bidonde S , Ben Amor M , Guis M , Ramassamy S , Zegzouti H , Pech J C , Latché A
Published: November 2023

The phytohormone ethylene controls many stages of plant development such as ripening of climacteric fruits, leaf and flower senescence, responses to wounding and invasion by pathogens (Abeleset al.,1992). The ethylene biosynthetic pathway includes two main steps: the conversion by ACC synthase of S-adenosylmethionine into1-amino- cyclopropane-1-carboxylic acid (ACC) the conversion of ACC into ethylene by ACC oxidase (Kende, 1993).
Neptunists, vulcanists, and plutonists
Authors: Hallam A
Published: November 2023

It is not unusual for the creators of a new discipline within science to deny their intellectual ancestors, rather as most adolescents rebel at some stage against their parents. No doubt this is a necessary phase of growing up and should be viewed indulgently. What is extraordinary about the self-proclaimed founders of modern geology, from Werner to Play fair and Lyell, is that until very recently standard historiography has taken them at their word and accepted their contemptuous dismissal of earlier thinkers about the earth as mere undisciplined speculators. Geology, according to Lyell, was not to be confounded with cosmogeny.
Mating, The Family, And Marriage: A Sociological View
Authors: Fletcher Ronald
Published: November 2023

It is worth while, indeed necessary, to begin by considering some questions which arise over the treatment of the subject (mating and marriage) in the three foregoing chapters. Worth while, in that these questions seem of some importance in themselves; necessary, in that they pave the way for what I want to say from some important viewpoints (there is no one conclusive and totally agreed viewpoint) within sociology. They can be stated quite briefly here, by way of introduction, but, later, will be seen-as indispensable elements-to be woven into the ongoing argument.
Introduction
Authors: Cartledge Bryan
Published: November 2023

The first two collections of Linacre Lectures-Monitoring the environment (OUP 1992) and Energy and the environment (OUP 1993)-concentrated on various aspects of the way in which human activity is affecting the long-term future of our planet and its habitability. The focus of this collection is more immediate. Rather than calculating the possibility of significant climatic change in the next century or weighing up the future environmental impact of different sources of energy-both immensely important areas of investigation-most of the lecturers on 'Health and the Environment' were describing problems which are already acute and were becoming more so as they spoke.
Nuclear power comes clean
Authors: Harding Christopher
Published: November 2023

I stood down after more than six years as Chairman of BNFL at the end of June 1992, having reached the conclusion that it was time for a change both for me and the company. However, my enthusiasm and commitment to nuclear energy remains unchanged, and what I have to say here is exactly what I would have said had I remained as Chairman of BNFL. I am very conscious of being something of an odd man out among the distinguished list of contributors to these lectures in that I am not a scientist. Yet I am addressing a subject with a large scientific content.
Population, food supply, and famine: an ecological or an economic dilemma
Authors: Seaman John
Published: November 2023

By the year 2060, world population is expected approximately to double from the current figure of around 5.5 billion to about 11 billion people. On the highest estimate, population may nearly triple, and only under the most favourable and unlikely conditions can we expect population to stabilize at approximately 8 billion people (UN Population Fund 1992). In a world which is already crowded, in which species are being extinguished daily, and where pollution and environmental degradation are already at alarming levels, it seems inconceivable that this growth in population can occur without a major calamity.
The relative roles of nature and nurture in common disease
Authors: Weatherall David
Published: November 2023

As a result of improvements in nutrition, hygiene, housing, and many other environmental factors, and with the advent of immunization and antibiotics, there has been a major decline in infectious disease in rich industrialized countries over the last half century. At the same time there has been a remarkable increase in the life expectancy of their populations and a reduction in infant mortality.