bluuebunny/crossref_metadata_2025_split huggingface dataset:
BEHAVIOURAL ECOLOGY OF COCKROACHES*
Authors: SCHAL COBY , GAUTIER J.‐Y. , BELL WILLIAM J. 
Published: January 2008

Summary1. Cockroaches are ubiquitous in most habitats where insects occur. Although most reports on cockroaches are physiological in nature, sufficient information is available to indicate that forest, desert, and cave‐dwelling cockroaches select microhabitats on the basis of finely resolved environmental preferences. This is particularly true for oviparous females which select specific substrates for oviposition and embryogenesis. Selection and diel movements between microhabitats are related to diel changes in micrometeorological profiles and predation, feeding, and enhancement of sexual communication.2. With some exceptions oviparous species live in wooded habitats; ovoviviparous species tend to occur in protected environments such as caves and logs. Oviparous species are exposed to greater predation, parasitism, and environmental pressures during embryogenesis than are ovoviviparous species, where internal incubation and some parental care reduce these risks. Most ovoviviparous species produce larger clutches, but the interval between broods is significantly longer than in oviparous species. Long gestation, clumping of food resources, and relatively little movement probably selected for male control of resources as a mate‐attraction tactic in ovoviviparous species; agonistic interactions, and in some cases morphological specializations for fighting, and highly ritualized behaviours are common. In most oviparous species, volatile pheromone communication and resource‐based aggregations are common. Rapid ovarian cycles and patchily distributed nutritional resources result in the need for greater mobility, and hence adults encounter greater risks.
Physiological Responses Of Birds To Flight And Running
Authors: BRACKENBURY JOHN 
Published: January 2008

Summary1. The energy required for sustained physical activity in flying and running birds is obtained from fatty acids mobilized from adipose stores under the influence of hormones. There is some evidence that glucagon, insulin and growth hormone may be involved in this process.2. Energy expenditure can increase up to 14 times and 12 times resting values in flying and running birds, respectively. Energy expenditure varies only slightly over the normal range of flight speeds in individual species, but in running birds there is a linear correlation between oxygen consumption and speed. The slope of this relationship is an inverse function of body weight and indicates the energy cost of transport in ml O2.kg‐1.m‐1.3. Increased oxygen demands by the working muscles are met by increased ventilation and circulation. Increased oxygen delivery by the blood is achieved by rises in cardiac output and oxygen extraction. Cardiac stroke volume changes relatively little and the increased cardiac output results mainly from an increase in heart rate. Regional blood distribution during exercise may be determined not only by the demands of the locomotory muscles but also by the need to increase heat loss from the skin and respiratory tract.4. Ventilatory movements during flight are frequently synchronized in a I:I fashion with wing movements. Increased ventilation during flight and running may be stimulated, not only by the need for increased gas exchange, but also in order to raise heat loss by respiratory evaporation. Thermal hyperventilation carries a risk of CO, washout from the lungs and consequent blood alkalosis. The risk is minimized in some species by appropriate alterations in the rate and depth of breathing, which help to confine excess ventilation to the respiratory dead space.5. Metabolic heat produced during exercise is either lost from the respiratory linings and the skin, or stored by the body with a resultant rise in body temperature. Changes in peripheral blood perfusion and active regulation of the feathers may assist cutaneous heat loss. Respiratory evaporation usually accounts for less than 30% of the total heat loss, even at high air temperatures, and becomes progressively less efficient at higher exercise intensities. At high air temperatures and high exercise intensities, most of the metabolic heat is stored, and exercise duration is limited as the body temperature approaches the upper lethal limit.
EVOLUTION OF CARDIOVASCULAR BARORECEPTOR CONTROL
Authors: BAGSHAW ROGER J. 
Published: January 2008

SummaryDuring animal evolution the circulatory system has shown a progressive modification in structure, function and short‐term control.Short‐term circulatory control has evolved from the limitation of a rising blood pressure via a reflex bradycardia to bidirectional control of blood pressure by appropriate reflex changes in heart rate, vascular resistance and impedance.Relevant experimental data ranges from extensive in mammals to nugatory in invertebrates. Baroreceptor research in intervening animal groups is varied, being particularly sparse in birds. This research is reviewed. There are few interspecies comparisons of baroreceptor physiology. Available data is complicated by variation in the techniques employed for assessing baroreceptor function. In non‐mammalian research the correlation of heart rate changes to pharmacologically induced changes in blood pressure predominate. In mammalian baroreceptor research methods based upon the ability of discrete baroreceptor sites to effect changes in the peripheral vasculature are more prevalent. All methods are susceptible to modification by other experimental variables, particularly the anaesthetic state of the animal.Available evidence shows a consistent response of a decreasing heart rate to baroreceptor loading throughout the vertebrates, with a progressive increase in the ability of the baroreceptors to change peripheral vascular resistance. These findings are consistent with the known, progressive trend from cholinergic to adrenergic control of the vascular system during evolution.Known baroreceptor sites appear to be located so as to protect the end‐organ or‐organs primarily at risk from inappropriate blood pressure changes; namely the gill vasculature in the fish, pulmonary circulation in the Amphibia and Reptilia, and the brain and heart in higher animal groups.It is postulated that the carotid sinus baroreceptors have developed in the Mammalia as a second functional baroreceptor site to provide extra protection against hypoperfusion of vital organs, particularly the heart and brain. In humans the dynamic aspects of cardiovascular carotid sinus control, particularly of skeletal muscle flow and integration with cardiopulmonary baroreceptors, may represent a specific response to the adoption of an upright stance. Extremes of environmental stress encountered in contemporary life may exceed the limitation of baroreceptor function in humans, as, for example, during gravitational loading particularly following periods of weightlessness and modification by endurance training.
KIN RECOGNITION: FUNCTIONS AND MECHANISMS A REVIEW
Authors: HEPPER PETER G. 
Published: January 2008

General Summary1. The aim of this paper has been to review the theory behind kin recognition to examine the benefits individuals obtain by recognizing their kin and to review the mechanisms used by individuals in their recognition of kin.2. The ability to discriminate between kin and non‐kin, and between different classes of kin gives individuals advantages in fitness greater than individuals unable to recognize their kin. Four specific areas of benefit were considered: altruistic behaviour, co‐operative behaviour, parental care and mate choice. Finally the possibility that kin recognition has arisen as a byproduct from some other ability was discussed.3. Mechanisms of kin recognition were considered with respect to three essential components of kin recognition. The cue used to discriminate kin, how individuals classify conspecifics as kin, etc. and how the ability to recognize kin develops.4. Individuals can use a number of cues to discriminate kin from non‐kin. These were divided into cues presented by conspecifics (conspecific cues), of which three types were considered: individual, genetic and group/colony cues, and non‐conspecific cues, environmental, state and no cues. Kin recognition could be achieved by use of all these cues.5. How individuals classify their conspecifics as kin, etc. can be achieved in a number of ways; dishabituation or self‐matching, which require no learning of kinship cues, or by phenotype matching or familiarity, both of which require the learning of kinship information.6. It may be necessary for individuals to acquire information concerning kinship. This may be learned, and can be achieved in a number of ways; physiological imprinting, exposure learning or associative learning. Acquisition by these means is non‐selective, in that the cues which are most salient in the individual's environment will be learned. Selectivity can be introduced into this process to increase the probability of acquiring kinship information by a number of means; learning from parents, sensitive periods for learning and prenatal learning. Finally, kinship information could be supplied by recognition genes.7. A distinction is drawn between cues which are used by an individual in the discrimination of kin, discriminators, and cues which are used by individuals in the acquisition of information about kinship, acquisitors.8. Experiments used to support previous categories of mechanisms of kin recognition were examined in the light of this discussion and it was found that the results were open to a number of different interpretations and yielded little specific information about the mechanisms of kin recognition.9. It was concluded that there was much evidence, both theoretical and experimental to support the proposed benefits individuals gain from recognizing kin, but much more research is required before the mechanisms of kin recognition are fully understood.
NITROGEN EXCRETION IN MARINE AND FRESH‐WATER CRUSTACEA
Authors: REGNAULT MICHÈLE 
Published: January 2008

Summary1. The major characteristic of aquatic Crustacea is ammonotelism as shown by the relative importance of various nitrogenous end‐products of their nitrogen metabolism.2. In contrast to urico‐ and ureo‐genesis pathways, ammoniogenesis pathways have received recent attention; some specific enzymes such as glutamate dehydrogenase, AMP‐deaminase and glutaminase are now admitted to play a possible key role in ammoniogenesis of various crustacean species.3. Processes involved in ammonia output through the gill epithelium (diffusion and/or ionic exchanges) are discussed though few data related to Crustacea are as yet available compared to those obtained in ammonotelic fishes.4. The effects of some environmental factors as well as the physiological state of animals on nitrogen excretion of Crustacea are envisaged. The effects of temperature, salinity and NH4 concentration in the external medium are discussed first, followed by the changes in nitrogen excretion associated with the moult cycle, the nutritional state of animals and possible neuroendocrine control. It is demonstrated that the response of the excretion rate to these factors presents various patterns according to the species, its osmoregulatory abilities and its body reserves. Changes can also occur in the requisite metabolic pathways, thus increasing the difficulty of generalization.5. In spite of the great diversity encountered within Crustacea an attempt to bring out general trends of their nitrogen excretion is proposed.6. The present review is focused on metabolic and physiological aspects of crustacean nitrogen excretion but the significance of nitrogen release in nutrient regeneration in marine and fresh‐water ecosystems is foreseen.
THE EFFECT OF ADDED NITROGEN ON THE RATE OF DECOMPOSITION OF ORGANIC MATTER
Authors: FOG KÅRE 
Published: January 2008

Summary(1) N added to decomposing organic matter often has no effect or a negative effect on microbial activity, at least in the long term. More than 60 papers are cited in support of this statement.(2) The negative effect of N is mainly found with recalcitrant organic matter with a high C/N ratio (straw, wood, etc.), whereas a positive effect of N is common for easily degradable organic material with low C/N ratio.(3) The negative effect of N could be explained by: (i) N disturbs the outcome of competition between potent and less potent decomposers; (ii) through ‘ammonia metabolite repression’, N blocks production of certain enzymes, at least in basidiomycetes, and enhances breakdown of the most available cellulose, whereby recalcitrant lignocellulose accumulates; (iii) amino compounds condense with polyphenols and other decomposition products, forming ‘browning precursors’ which are toxic or inhibitory.(4) The effect of adding N may depend on the microflora present.(5) There are indications that some microorganisms have a ‘luxury uptake’ of N when it is present in sufficient amounts, thereby delaying N mineralization.(6) The addition of N seems to increase the formation of water‐soluble, brown, recalcitrant compounds, but to decrease the amount of humus formed.
DEVELOPMENTAL PROCESSES, DEVELOPMENTAL SEQUENCES AND EARLY VERTEBRATE PHYLOGENY
Authors: LANGILLE ROBERT M. , HALL BRIAN K. 
Published: January 2008

Summary(1) We have put forth the position that evolutionary sequences can be deduced by an analysis of fundamental developmental sequences. Such sequences are highly conserved within a group and ‘contain steps which are necessary to achieve a developmental fate’. The premise of our work then, is that such fundamental sequences do not arise de novo time and time again but can be traced back through their evolutionary history in organisms which contain portions of the sequence.(2) These highly conserved developmental sequences are in fact developmental constraints to evolution in as much as natural selection has not been able to discard them, but rather has utilized them in achieving evolutionary change.(3) We have demonstrated the ability to use developmental data by producing an evolutionary sequence for the origin of the vertebrates using the processes of neuralization and cephalization, the latter due primarily to the influences of the neural crest and epidermal placodes. The evolutionary sequence created, while not novel in structure, is distinct in that it was created solely by following a developmental sequence that is highly conserved among the vertebrates. The sequence is:(a) Chordamesoderm differentiates from the surrounding mesoderm and induces an overlying neural tube.(b) Through the influence of neuralizing morphogens, the neural tube differentiates into anterior (fore‐, mid‐ and hindbrain) and posterior (spinal cord) parts. Cephalization has begun.(c) Cephalization proceeds via the development of two new populations of embryonic cells, the neural crest, a derivative of the neural epithelium and the epidermal placodes, derivatives of the ectoderm immediately adjacent to the neural tube. These two populations contribute significantly to the subsequent development of the vertebrate head including the skeleton, connective tissues, cranial nerve and sensory organs.Sequence (a) occurs in the most primitive protochordates and is one of the differences between the chordates and deuterostome invertebrates. Sequence (b) occurred next leading to a protochordate with a differentiated central nervous system, but lacking most vertebrate head structures. Sequence (c) signalled the beginning of the true vertebrates or branchiates (after the branchial arches which all vertebrates' share) since the production of a neurocranium, viscerocranium, cephalic armour, teeth and cranial peripheral ganglia was only possible with the acquisition of this developmental step.(4) Current investigations into the cellular, molecular and biochemical basis of developmental sequences will allow biologists to test for the integrity of these developmental sequences and to test for their presence in the ontogenies of any species in question. These investigations will ascertain the validity of determining an evolutionary sequence based on a particular developmental process(es) as outlined in the present paper.
WILD MICE IN THE COLD: SOME FINDINGS ON ADAPTATION
Authors: BARNETT S. A. , DICKSON R. G. 
Published: January 2008

SummaryThe house mouse, Mus domesticus, can thrive in natural environments much below its optimum temperature. Thermogenesis is then above that at more usual temperatures. In addition, body weight, and the weights of brown adipose tissue and the kidneys, may be higher than usual. In free populations of house mice cold lowers fertility and may prevent breeding. Other possible limiting factors on breeding are food supply, shelter for nesting and social interactions.In captivity, wild‐type house mice exposed to severe cold (around o °C) at first adapt ontogenetically by shivering and reduced activity. But raised thermogenesis is soon achieved without shivering; nest‐building improves; and readiness to explore may be enhanced. Endocrine changes probably include, at least initially, a rise in adrenal cortical activity and in catecholamine secretion. Some females become barren, but many remain fertile. The maturity of fertile females is, however, delayed and intervals between births are lengthened; nestling mortality rises. A limiting factor during lactation may be the capacity of the gut. Similar adaptive changes are observed during winter in some species of small mammals that do not hibernate. But neither the house mouse nor other species present a single, universal pattern of cold‐adaptation.Wild‐type mice bred for about 10 generations in a warm laboratory environment (20–23 °C) change little over generations. In cold they become progressively heavier and fatter at all ages; they mature earlier, and nestling mortality declines. The milk of such ‘Eskimo’ females is more concentrated than that of controls. If ‘Eskimo’ mice are returned to a warm environment, they are more fertile, and rear heavier young, than controls that remained in the warm. Despite the heavier young, litter size is not reduced: it may be increased, probably as a result of a higher ovulation rate.Parental effects have been analyzed by cross‐fostering and hybridizing. Survival, growth and fertility are all favourably influenced by the intra‐uterine and nest environments provided by ‘Eskimo’ females. ‘Eskimo’ males are also better fathers. Hence after ten generations the phenotype of cold‐adapted house mice shows the combined effects of (a) an ontogenetic response to cold, (b) a superior parental environment and (c) a changed genotype.The secular changes in the cold that lead to this phenotype give the appearance of evolution in miniature; but it is equally possible that they represent a genetical versatility that allows rapid, reversible shifts in response to environmental demands. The adaptation of house mice to extreme environments, whether progressive or reversible, is aided by a complex interaction between generations.
HOW FREQUENT ARE SUPERIOR GENOTYPES IN PLANT BREEDING POPULATIONS?
Authors: SIMMONDS N. W. 
Published: January 2008

SummaryA search of plant breeding literature has produced 69 examples in which reasonable judgements could be made as to potential for genetic advance. The crops covered are all inbreeders (predominantly cereals) or outbred clones. The average potential for genetic advance (roughly 60 % of examples were favourable) seemed to be far higher than would usually be expected and to indicate therefore that excellent new crop varieties should be more frequent than experience suggests. The discrepancy may be partly explained by various biases but the main conclusion is that superior genotypes are indeed fairly frequent but that selection efficiency is too low to take better advantage of them.
PATTERNS IN THE GEOGRAPHICAL RANGES OF SPECIES
Authors: GASTON KEVIN J. 
Published: January 2008

Summary1. A growing number of studies have documented patterns in species geographic ranges relevant to the study of community structure. These include patterns in the frequency of geographic ranges of different sizes, and in the interaction of range sizes with population abundances and variabilities, body sizes, trophic characteristics and extinction probabilities.2. Agreement between hypothesized and observed relationships is reasonably good, but we do not know how general the patterns are. Analysis of patterns has focused upon a few taxonomic groups, a bias largely resulting from a lack of information on the geographic distributions of most taxa.3. Many of the patterns are interrelated, and although theoretical bases to all the patterns can be suggested, it is possible that some are artifacts.4. Taylor power plots give us a means of making predictions about population behaviour as it pertains to geographic ranges. Some of these predictions suggest that previous conceptions of such interactions have been too narrow, but empirical analyses of these patterns will be hampered by the difficulty of measuring population variability.5. In general, our knowledge of the structure, and spatial and temporal behaviour, of species geographic ranges remains poor.
SEX RATIOS AND CONDITIONS REQUIRED FOR ENVIRONMENTAL SEX DETERMINATION IN ANIMALS
Authors: KORPELAINEN HELENA 
Published: January 2008

Conclusions and SummaryEnvironmental sex determination (ESD) is a system of sexual determination that is influenced by a variable environment. Once sex is determined it is then fixed for life. The model of Charnov & Bull (1977) proposes that ESD is favoured by natural selection when an individual's fitness as a male or female is strongly influenced by environmental conditions and when the individual has little control over which environment it will experience. Adaptive sex ratio variation is considerably easier for organisms with ESD, and this feature is the ultimate cause for the evolution and maintenance of ESD. ESD is taxonomically widely expressed, and more cases are likely to be discovered. Both environmental and genotypic sex determination mechanisms are found in closely related species. Evidence of geographical variation in the degree and in the critical environmental values of ESD within the same species has also been discovered, e.g. in the fish Menidia menidia and in the crustacean Gammarus duebeni.The factors causing sex determination in invertebrates include temperature, daylength, nutrition, density, humidity, ionic composition of the environment, pH, carbon dioxide, UV light, metabolic products, parasites, exposure to the opposite sex of the same species, and in parasitoids also host size, age and type. In vertebrates temperature is the dominant factor causing sex determination, though in fish also pH, salinity, light, water quality and nutrition, and in turtles water potential of the substrate have some effect on the sex expression. Most of these factors influence growth through resource availability or developmental speed. In most cases of ESD in invertebrates and fish, the environmental factor has a gradual effect on the sex expression, in contrast to the typical steep threshold mode found in reptiles. These differences might be due to the fact that invertebrates exhibiting ESD are commonly parasitic or confined to aquatic environments, where less spatial microhabitat differentiation exists. Sex ratio data available from nature for animals with ESD are quite limited, except for reptiles. In the laboratory sex ratios can be varied more widely than what is observed in nature.There are a number of characteristic features some of which are found in each species exhibiting ESD: (1) Patchy environments, (2) variable sex ratios, (3) parthenogenesis in addition to bisexuality, (4) parasitism, (5) aquatic habitats, (6) sexual dimorphism, (7) females larger than males, and (8) local mate competition.