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Spatial variation in host plant availability may lead to specialization in host use and local host adaptation in herbivorous insects, which may involve a cost in performance on other hosts. We studied two geographically separated populations of the seed beetle Megacerus eulophus (Coleoptera: Bruchidae) in central Chile: a population from the host Convolvulus chilensis (in Aucó) and a population from C. bonariensis (in Algarrobo). In Aucó C. chilensis is the only host plant, while in Algarrobo both C. bonariensis and C. chilensis are available. We tested local adaptation to these native host plants and its influence on the use of another, exotic host plant. We hypothesized that local adaptation would be verified, particularly for the one-host population (Aucó), and that the Aucó population would be less able to use an alternative, high-quality host. We found evidence of local adaptation in the population from C. chilensis. Thus, when reared on C. chilensis, adults from the C. chilensis population were larger and lived longer than individuals from the C. bonariensis population, while bruchids from the two populations had the same body size and longevity when reared on C. bonariensis. Overall, bruchids from the C. chilensis population showed greater performance traits than those from the C. bonariensis population. There were no differences between the bruchid populations in their ability to use the alternative, exotic host Calystegia sepium, as shown by body size and longevity patterns. Results suggest that differences in local adaptation might be explained by differential host availability in the study populations.

Experiments were conducted to study sexual isolation among two natural populations of Drosophila ananassae maintained at 18 degrees C and 24 degrees C for 12 generations in the laboratory to see the effect of this environmental variable on behavioural isolation. Multiple choice technique was used and matings were observed directly in Elens Wattiaux mating chamber. Results showed sexual isolation among strains that were maintained at different temperatures, indicating that temperature may have affected the mating behaviour of the flies which resulted in the induction of ethological isolation among the strains.

Assessment of ecological impacts of toxicants relies currently on extrapolation of effects observed at organismal or population levels. The uncertainty inherent to such extrapolations, together with the impossibility of predicting ecological effects of chemical mixtures, can only be resolved by adopting approaches that consider toxicological endpoints at a community or ecological level. Experimental data from micro- and mesocosms provide estimates of community effect levels, which can then be used to confirm or correct the extrapolations from theoretical methods such as species sensitivity distributions (SSDs) or others. When assessing impacts, the choice of sensitive community endpoints is important. Four community endpoints (species richness, abundance, diversity and similarity indices) were evaluated in their ability to assess impacts of two insecticides, imidacloprid and etofenprox, and their mixture on aquatic and benthic communities from artificial rice paddies. Proportional changes of each community endpoint were expressed by ratios between their values in the treatment and control paddies. Regression lines fitted to the endpoint ratios against the time series of chemical concentrations were used to predict percentile impacts in the communities. The abundance endpoint appears to be the most sensitive indicator of the communities' response, but the Czekanowski similarity index described best the structural changes that occur in all communities. Aquatic arthropods were more sensitive to the mixture of both insecticides than zooplankton and benthic communities. Estimated protective levels for 95% of aquatic species exposed to imidacloprid (<0.01-1.0 μg l(-1)) were slightly lower than predicted by SSD, whereas for etofenprox the protective concentrations in water (<0.01-0.58 μg l(-1)) were an order of magnitude lower than SSD's predictions.

Recently, many studies have been conducted on manual laterality in chimpanzees. Nevertheless, whether nonhuman primates exhibit population-level handedness remains a topic of considerable debate. One of the behaviors studied has been bimanual coordinated actions. Although recent studies have highlighted that captive chimpanzees show handedness at population level for these tasks, some authors have questioned the validity and consistency of these results. The first reason has been the humanization of the samples. The second one has been that the results refer to animals in American biomedical centers and the studies were conducted by the same team [WD Hopkins et al.]. This article aims to assess the laterality in bimanual coordination (tube task) activities in animals housed in an intermediate environment (Chimfunshi, Zambia). This has been conducted by replicating previous studies on similar samples (Mona Foundation, Spain), and then by extending the results to chimpanzees housed in intermediate settings. Individuals were evaluated through four experimental sessions (tests). Results indicated that 86% of the Chimfunshi sample was lateralized (48% RH, 38% LH). Furthermore, the sample showed population-level right-handedness in the mean handedness index, in Test 1, Test 2, and the first half of the study (Test 112). Rearing experience did not have an influence on handpreference. Taken together, the two sample (intermediate settings: Chimfunshi and Mona) results indicate a clear right-handedness. In conclusion, this replication and extension shows that (1) the Mona and Chimfunshi chimpanzees are right-handed in certain conditions, (2) the results are consistent with those obtained by Hopkins in captive settings, (3) the humanization of the samples does not affect manual laterality, (4) females are right-handed at population-level, but not males, and (5) these results reinforce the fact that the complexity of the task plays a dominant role in the expression of hand laterality among chimpanzees., (2010 Wiley-Liss, Inc.)

In a recent paper List, Elsholtz and Seeley (List et al., 2009) have devised an agent-based model of the nest-choice dynamics in swarms of honeybees, and have concluded that both interdependence and independence are needed for the bees to reach a consensus on the best nest site. We here present a simplified version of the model which can be treated analytically with the tools of statistical physics and which largely has the same features as the original dynamics. Based on our analytical approaches it is possible to characterize the co-ordination outcome exactly on the deterministic level, and to a good approximation if stochastic effects are taken into account, reducing the need for computer simulations on the agent-based level. In the second part of the paper we present a spatial extension, and show that transient non-trivial patterns emerge, before consensus is reached. Approaches in terms of Langevin equations for continuous field variables are discussed.

Humans have drastically changed much of the world's acoustic background with anthropogenic sounds that are markedly different in pitch and amplitude than sounds in most natural habitats. This novel acoustic background may be detrimental for many species, particularly birds. We evaluated conservation concerns that noise limits bird distributions and reduces nesting success via a natural experiment to isolate the effects of noise from confounding stimuli and to control for the effect of noise on observer detection biases. We show that noise alone reduces nesting species richness and leads to different avian communities. Contrary to expectations, noise indirectly facilitates reproductive success of individuals nesting in noisy areas as a result of the disruption of predator-prey interactions. The higher reproductive success for birds within noisy habitats may be a previously unrecognized factor contributing to the success of urban-adapted species and the loss of birds less tolerant of noise. Additionally, our findings suggest that noise can have cascading consequences for communities through altered species interactions. Given that noise pollution is becoming ubiquitous throughout much of the world, knowledge of species-specific responses to noise and the cumulative effects of these novel acoustics may be crucial to understanding and managing human-altered landscapes.

A new study on the impact of anthropogenic noise on birds takes a behavioural discipline to the level of community ecology: noise can not only harm individual species but also alter species relationships.

Little is known about whether adaptations to an insular life also involve adaptations in basal corticosterone levels or in the adrenocortical stress response, thus being part of a genetically based island syndrome. However, differences in corticosterone between island and mainland may also be a direct phenotypic response to differences in environmental conditions or may depend on individual characteristics of the animal such as body condition or parental investment. In this paper, we investigated whether insular (Island of Corsica) and mainland (nearby Southern France) blue tits Parus caeruleus populations differed in baseline and handling-stress induced corticosterone levels during the breeding season as a response to biological changes of insular biota. We also examined whether corticosterone levels of both mainland and insular blue tits differed between birds living in two different habitats (summergreen and evergreen oak woods) that differ in food availability and whether individual characteristics affected corticosterone levels. We found (a) differences in baseline corticosterone plasma levels between Corsica and the mainland, independent of regional differences in fat scores, (b) a regional difference in the relationship between corticosterone levels and brood size, (c) a difference in the rapidity of onset of the stress response to handling between habitats, independent of region, and (d) a negative relationship between body fat stores and baseline corticosterone levels independent of region. Reduced baseline corticosterone levels on Corsica may be a component of the insular syndrome, allowing birds to be less aggressive and to enhance parental investment despite higher breeding densities. We suggest that baseline corticosterone levels are only elevated if food availability affects directly the parents. However, when conditions deteriorate unexpectedly (as mimicked by handling stress), food allocation between parents and offspring needs to be re-adjusted in favor of the parents, possibly by increased circulating corticosterone levels. The switch to self-maintenance seems to be modified by the amount of body energy stores.

New Zealand fur seals in the Kaikoura region breed near a town with expanding tourist and fishing industries and commonly come ashore entangled in nets and plastic debris. However, the rate at which entanglement occurs was previously unknown. A decade of Department of Conservation seal callout data was analysed to determine the level of entanglement in the region and the most common debris type. Monitoring of adult female fur seals released from entanglement provided information on the potential for serious wounds to heal and survivorship of released individuals. Entanglement rates of pinnipeds in Kaikoura are some of the highest reported world-wide (average range: 0.6-2.8%) with green trawl net (42%), and plastic strapping tape (31%) together contributing the most to debris types. Nearly half of the reported entangled seals are successfully released (43%) and post-release monitoring shows that with appropriate intervention the chance of an individual surviving even with a significant entanglement wound is high. Our study demonstrates that while entanglement in the region is high, a successful intervention protocol may help reduce the potential for entanglement-related mortality in the region.

Millions of years before we began to manipulate the flow of light using synthetic structures, biological systems were using nanometre-scale architectures to produce striking optical effects. An astonishing variety of natural photonic structures exists: a species of Brittlestar uses photonic elements composed of calcite to collect light, Morpho butterflies use multiple layers of cuticle and air to produce their striking blue colour and some insects use arrays of elements, known as nipple arrays, to reduce reflectivity in their compound eyes. Natural photonic structures are providing inspiration for technological applications.

A multimedia program, a non-linear system which supplements the traditional, linear way of learning (e.g. with a text book), was developed. Non-linear systems allow the direct use of information in a free sequence. A problem of these systems is the danger that the reader becomes lost in detail. Therefore, a program was constructed which tries to combine the properties of linear and non-linear teaching systems. Student groups were continuously involved during all stages of the project. The program is organized in several levels. These are: (1) choice of chapters; (2) table of contents of one chapter; (3) summary; (4) text and (5) pictures, animations, simulations and video sequences. The program can be used in different ways. In the linear mode, the reader selects via action words different levels of the program. The user can read either only on the level of the summaries or on detailed information (text, pictures, simulations and videos). In the non-linear mode the user jumps via menu items or buttons to selected pictures, simulations or a searched term. In this way, more than 3500 screen pages are integrated into a multimedia program for veterinary physiology. The program is written in TOOLBOOK, and can be used on a personal computer with Windows 95 or higher.

According to the 'mental time travel hypothesis' animals, unlike humans, cannot mentally travel backwards in time to recollect specific past events (episodic memory) or forwards to anticipate future needs (future planning). Until recently, there was little evidence in animals for either ability. Experiments on memory in food-caching birds, however, question this assumption by showing that western scrub-jays form integrated, flexible, trial-unique memories of what they hid, where and when. Moreover, these birds can adjust their caching behaviour in anticipation of future needs. We suggest that some animals have elements of both episodic-like memory and future planning.

Damage caused by introduced species results from the high population densities and large body sizes that they attain in their new location. Escape from the effects of natural enemies is a frequent explanation given for the success of introduced species. Because some parasites can reduce host density and decrease body size, an invader that leaves parasites behind and encounters few new parasites can experience a demographic release and become a pest. To test whether introduced species are less parasitized, we have compared the parasites of exotic species in their native and introduced ranges, using 26 host species of molluscs, crustaceans, fishes, birds, mammals, amphibians and reptiles. Here we report that the number of parasite species found in native populations is twice that found in exotic populations. In addition, introduced populations are less heavily parasitized (in terms of percentage infected) than are native populations. Reduced parasitization of introduced species has several causes, including reduced probability of the introduction of parasites with exotic species (or early extinction after host establishment), absence of other required hosts in the new location, and the host-specific limitations of native parasites adapting to new hosts.

Resource allocation within individuals may often be hierarchical, and this may have important effects on genetic correlations and on trait evolution. For example, organisms may divide energy between reproduction and somatic growth and then subdivide reproductive resources. Genetic variation in allocation to pathways early in such hierarchies (e.g., reproduction) can cause positive genetic correlations between traits that trade off (e.g., offspring size and number) because some individuals invest more resources in reproduction than others. We used quantitative-genetic models to explore the evolutionary implications of allocation hierarchies. Our results showed that when variation in allocation early in the hierarchy exceeds subsequent variation in allocation, genetic covariances and initial responses to selection do not reflect trade-offs occurring at later levels in the hierarchy. This general pattern was evident for many starting allocations and optima and for whether traits contributed multiplicatively or additively to fitness. Finally, artificial selection on a single trait revealed masked trade-offs when variation in early allocation was comparable to subsequent variation in allocation. This result confirms artificial selection as a powerful, but not foolproof, method of detecting trade-offs. Thus, allocation hierarchies can profoundly affect life-history evolution by causing traits to evolve in the opposite direction to that predicted by trade-offs.

The beneficial effect of plant foods on human health is unmistakable. Time and time again, studies have found foods of plant origin to reduce the risk of most major chronic illnesses suffered by the human population. Possible mechanisms for the preventative effects of these foods are discussed. Each of the plant groups reviewed was found to reduce the risk of one or more of the following: cardiovascular disease, cancer (lung, breast, colon, rectal, prostate, epithelial, stomach, esophageal, oral, pharynx, larynx, urinary tract, endometrium, pancreas, thyroid, liver, ovary, gallbladder, bladder, and kidney), diabetes, hypertension, bone degeneration, diverticulitis, constipation, gallstones, age-related blindness. Almost no evidence was found to suggest a negative effect on health due to consumption of these plant foods. Based on this material and a review of conserved animal signaling molecules we surmise that animals require these chemicals to enhance specific mammalian cellular processes, demonstrating phyto-zooidal signaling. Further, this diet dependency coupling between plants and animals probably evolved because of the abundance of a particular plant material in a local environment, which is now broken because of technological advances. In conclusion, the overwhelming majority of evidence shows that people may significantly decrease their risks of the aforementioned diseases by increasing their intake of these foods since they represent a natural method to enhance animal processes and signaling.

We evaluated the in vitro development of porcine zygotes that were cultured in a novel culture medium, porcine zygote medium (PZM), under different conditions and compared to in vivo development. The viability of these zygotes to full term after culture was also evaluated by embryo transfer to recipients. Porcine single-cell zygotes were collected from gilts on Day 2 after hCG injection. Culture of zygotes in PZM containing 3 mg/ml of BSA (PZM-3) produced better results in terms of proportion of Day 6 blastocysts, Day 8 hatching rate, and numbers of inner cell mass (ICM) cells and total cells in Day 8 embryos than that in North Carolina State University (NCSU)-23 medium. In culture with PZM-3, embryo development was optimized in an atmosphere of 5% CO2:5% O2:90% N2 compared to 5% CO2 in air. The ICM and total cell numbers in Day 6 embryos cultured in PZM-3 or in PZM-3 in which BSA was replaced with 3 mg/ml of polyvinyl alcohol (PZM-4) were also greater than those of NCSU-23 but less than those developed in vivo. However, no difference was found in the ratio of ICM to total cells among embryos developed in PZM-3, PZM-4, or in vivo. When the Day 6 embryos that developed in PZM-4 (99 embryos) or in vivo (100 embryos) were each transferred into six recipients, no difference was found in the farrowing rate (83.3% for both treatments) and in the number of piglets born (33 and 42 piglets, respectively). Our results indicate that porcine zygotes can develop into blastocysts in a chemically defined medium and to full term by transfer to recipients after culture.

Four large (n > 1000) populations of Drosophila melanogaster, derived from control populations maintained on a 3 week discrete generation cycle, were subjected to selection for fast development and early reproduction. Egg to eclosion survivorship and development time and dry weight at eclosion were monitored every 10 generations. Over 70 generations of selection, development time in the selected populations decreased by approximately 36 h relative to controls, a 20% decline. The difference in male and female development time was also reduced in the selected populations. Flies from the selected populations were increasingly lighter at eclosion than controls, with the reduction in dry weight at eclosion over 70 generations of selection being approximately 45% in males and 39% in females. Larval growth rate (dry weight at eclosion/development time) was also reduced in the selected lines over 70 generations, relative to controls, by approximately 32% in males and 24% in females. However, part of this relative reduction was due to an increase in growth rate of the controls populations, presumably an expression of adaptation to conditions in our laboratory. After 50 generations of selection had elapsed, a considerable and increasing pre-adult viability cost to faster development became apparent, with viability in the selected populations being about 22% less than that of controls at generation 70 of selection.

Polar, alpine and temperate ectothermic (cold-blooded) animals encounter temperatures below the melting point of their body fluids either diurnally or seasonally. These animals have developed a number of biochemical and physiological adaptations to survive the low temperatures. The problems posed to the animals during cold periods include changes in membrane and protein structure due to phase changes in these molecules, changes in electrolyte concentrations and other solutes in the body fluids as well as changes in metabolism. Cold-tolerant ectothermic animals can be divided into two groups depending which of two 'strategies' they employ to survive the low temperatures: freeze-tolerant animals which survive ice formation in the tissues and freeze-avoiding animals which tolerate the low temperatures but not crystallization of the body fluids. The adaptations are mainly directed towards the control or avoidance of ice formation and include the synthesis of low mol. wt cryoprotectants, ice-nucleating agents and antifreeze proteins. However, some of the adaptations such as the synthesis of low mol. wt cryoprotectants are also more specific in their mechanism, e.g. direct stabilizing interaction with membranes and proteins. The mechanisms employed by such animals may offer ideas and information on alternative approaches which might be usefully employed in the cryopreservation of cells and tissues frequently required in assisted reproductive technology.

A indoor simulating test showed that there existed a close relationship between the community structure of soil animal and the concentration of soil Cd. When the concentration of soil Cd was high (99.48 mg.kg-1), the species, quantity, diversity index, homogeneous index, and abundance of soil animal were low. With the concentration going down, all indexes above increased gradually. When the concentration of soil Cd was 2.27 mg.kg-1, all the indexes were the same as control. The species and individuals of soil animal were negatively related with the natural logarithm of Cd concentration in soil.

This paper reviewed the studies on the compensatory growth of aquatic animals after starvation or undernourisment. The extent of compensatory growth, its affecting factors, physiological mechanisms, changes in chemical composition and dynamics of growth rate were discussed. The experimental design problems and the application prospects of related studied were also analyzed.

Dr Miriam Rothschild had an owl who became so jealous when Rothschild's daughter was born, the bird would try to attack both her and the child. Animals can often appear to have emotions, to be highly intelligent, motivated and sentient but are they conscious?

The ability to polarize is a fundamental property of cells. The yeast Saccharomyces cerevisiae has proven to be a fertile ground for dissecting the molecular mechanisms that regulate cell polarity during growth. Here we discuss the signaling pathways that regulate polarity. In the second installment of this two-part commentary, which appears in the next issue of Journal of Cell Science, we discuss how the actin cytoskeleton responds to these signals and guides the polarity of essentially all events in the yeast cell cycle. During the cell cycle, yeast cells assume alternative states of polarized growth, which range from tightly focused apical growth to non-focused isotropic growth. RhoGTPases, and in particular Cdc42p, are essential to guiding this polarity. The distribution of Cdc42p at the cell cortex establishes cell polarity. Cyclin-dependent protein kinase, Ras, and heterotrimeric G proteins all modulate yeast cell polarity in part by altering the distribution of Cdc42p. In turn, Cdc42p generates feedback signals to these molecules in order to establish stable polarity states and coordinate cytoskeletal organization with the cell cycle. Given that many of these signaling pathways are present in both fungi and animals, they are probably ancient and conserved mechanisms for regulating polarity.

Using a computational model for the population growth and dispersal of a model species in a fluctuating environment, we test three nature reserve geometries (one large, many small, and a self-similar distribution of reserve sizes) to determine which geometry maximizes species longevity. The self-similar distribution is a close approximation to the distribution of managed areas in the conterminous United States. We consider models with and without migration from or between reserve fragments and both short- and long-range dispersal mechanisms. The optimal geometry depends on the type of dispersal and on the relative probability of survival in protected and non-protected areas. When no migration is allowed from or between reserve fragments of the three geometries, many small equally sized reserves are the optimal geometry. When migration is allowed, the optimal geometry is a single large reserve when the survivability in non-protected areas is low and a self-similar distribution when the survivability is high., (Copyright 2000 Academic Press.)

Recent evidence that a syntaxin is required for cytokinesis in Caenorhabditis elegans embryos suggests that the mechanism of cell division in plant and animal cells may be more similar than previously imagined.

Chemical reactor theory under the premise of maximization of net rate of nutrient absorption has been used to predict throughput time, tau, of digesta in animals. Animals that feed on hexoses, such as many vertebrate fruit and nectar eaters, are of central interest in testing reactor theory because they use no hydrolysis before absorption and, hence, should provide valuable, simplified test cases. Graphical methods based on batch reactors and used to make such predictions in the past can give optimal gut throughput times (tauopt) identical with predictions from continuous plug-flow reactor models derived here: in animals with passive, linear uptake alone, tauopt should decline as hexose concentration of food increases. If saturating active uptake is involved, however, a minimum in tauopt (maximum in ingestion rate) is predicted at intermediate hexose concentration, the exact location of this minimum depending on costs of ingestion as well as on uptake kinetics. That is, tauopt first falls to a minimum with increasing hexose concentration and then increases. Optimal throughput time rises as uptake sites become saturated because there is little gross gain and no net gain from increased ingestion rate when uptake already is nearly saturated. It also rises with increasing costs of ingestion. The continuous-time analytic solutions provided here further make the novel and very general prediction of high sensitivity to decreasing tau below tauopt.

Circadian clocks control temporal structure in practically all organisms and on all levels of biology, from gene expression to complex behaviour and cognition. Over the last decades, research has begun to unravel the physiological and, more recently, molecular mechanisms that underlie this endogenous temporal programme. The generation of circadian rhythms can be explained, at the molecular level, by a model based upon a set of genes and their products which form an autoregulating negative feedback loop. The elements contributing to this transcriptional feedback appear to be conserved from insects to mammals. Here, we summarize the process of the genetic and molecular research that led to 'closing the molecular loop'. Now that the reductionist approach has led to the description of a detailed clock model at the molecular level, further insights into the circadian system can be provided by combining the extensive knowledge gained from decades of physiological research with molecular tools, thereby reconstructing the clock within the organism and its environment. We describe experiments combining old and new tools and show that they constitute a powerful approach to understanding the mechanisms that lead to temporal structure in complex behaviour.

The Myb family of proteins is a group of functionally diverse transcriptional activators found in both plants and animals that is characterized by a conserved DNA-binding domain of approximately 50 amino acids. Phylogenetic analyses of amino acid sequences of this family of proteins portray very disparate evolutionary histories in plants and animals. Animal Myb proteins have diverged from a common ancestor, while plants appear related only within the DNA-binding domain. Results imply a pattern of modular evolution of the Myb proteins centering on the possession of a helix-turn-helix motif. Based on this it is suggested that Myb proteins are a polyphyletic group related only by a "Myb-box" DNA-binding motif.

Wounds in animals are a common and frequent reason for seeking veterinary attention. The way in which wounds are managed affect the rate of healing, the time to return to normal function, the final cosmetic appearance, and hence the satisfaction of customers. The management of wounds depends on the stage of wound healing and can include irrigation, mechanical and chemical debridement, the use of antiseptics and antimicrobials, adherent and nonadherent dressings, and miscellaneous topical applications such as aloe vera, honey and live yeast cell derivative. The advantages, disadvantages and indications for initial wound management, topical applicants and dressings are discussed.

The unexpected notion that disease resistance mechanisms may use similar regulatory pathways to developmental processes has emerged from recent advances in understanding signal transduction pathways in insects, mammals and plants.

Production and consumption processes in soils contribute to the global cycles of many trace gases (CH4, CO, OCS, H2, N2O, and NO) that are relevant for atmospheric chemistry and climate. Soil microbial processes contribute substantially to the budgets of atmospheric trace gases. The flux of trace gases between soil and atmosphere is usually the result of simultaneously operating production and consumption processes in soil: The relevant processes are not yet proven with absolute certainty, but the following are likely for trace gas consumption: H2 oxidation by abiontic soil enzymes; CO cooxidation by the ammonium monooxygenase of nitrifying bacteria; CH4 oxidation by unknown methanotrophic bacteria that utilize CH4 for growth; OCS hydrolysis by bacteria containing carbonic anhydrase; N2O reduction to N2 by denitrifying bacteria; NO consumption by either reduction to N2O in denitrifiers or oxidation to nitrate in heterotrophic bacteria. Wetland soils, in contrast to upland soils are generally anoxic and thus support the production of trace gases (H2, CO, CH4, N2O, and NO) by anaerobic bacteria such as fermenters, methanogens, acetogens, sulfate reducers, and denitrifiers. Methane is the dominant gaseous product of anaerobic degradation of organic matter and is released into the atmosphere, whereas the other trace gases are only intermediates, which are mostly cycled within the anoxic habitat. A significant percentage of the produced methane is oxidized by methanotrophic bacteria at anoxic-oxic interfaces such as the soil surface and the root surface of aquatic plants that serve as conduits for O2 transport into and CH4 transport out of the wetland soils. The dominant production processes in upland soils are different from those in wetland soils and include H2 production by biological N2 fixation, CO production by chemical decomposition of soil organic matter, and NO and N2O production by nitrification and denitrification. The processes responsible for CH4 production in upland soils are completely unclear, as are the OCS production processes in general. A problem for future research is the attribution of trace gas metabolic processes not only to functional groups of microorganisms but also to particular taxa. Thus, it is completely unclear how important microbial diversity is for the control of trace gas flux at the ecosystem level. However, different microbial communities may be part of the reason for differences in trace gas metabolism, e.g., effects of nitrogen fertilizers on CH4 uptake by soil; decrease of CH4 production with decreasing temperature; or different rates and modes of NO and N2O production in different soils and under different conditions.

The study of microscopic animals should be intensified because: most of the world's animal biomass consists of very small animals; life as a small animal is both qualitatively and quantitatively very different from that of a large animal; and almost all animals are very small as they begin their development. Fortunately, developing technology now allows us to make quantitative measurements in microscopic animals. This paper describes new techniques for measuring cardiovascular variables such as blood pressure, stroke volume, heart rate and cardiac output in animals weighing as little as a few mg. Non-invasive techniques such as videomicroscopy can be used for determining heart stroke volume in small animals. Impedance measurement is another non-invasive or minor invasive technique for determining rates of heart beat, gill or lung ventilation and limb movement as well as giving qualitative information on changes in blood flow. Pulsed Doppler technology can be used to obtain blood flow velocity in small vessels. Invasive techniques depend on servo-null micropressure systems that record pressure through glass microelectrodes that are implanted into the vessel or heart lumen. This allows stable pressure recordings for up to 5-6 h in animals weighing as little as a few mg. Microinjectors can be used for intravascular injections of vasoactive drugs (or blood withdrawals). Newly emerging techniques for in vivo cardiovascular measurements allow us to understand the function of the cardiovascular system in a larger portion of the world's animal biomass, as well as in the immature and as yet poorly understood early developmental stages of animals.

This paper will address two aspects regarding the antioxidative role of coenzyme Q (CoQ): (1) Is the antioxidant function of CoQ primary or secondary (coincidental), i.e. was this molecule selected during evolution to function primarily as an essential functional component of the mitochondrial electron transfer chain and oxidative phosphorylation processes, is its antioxidative capability merely a coincidence of its hydroquinone structure, or was its synthetic enzyme sequence selected on the basis of the advantage to the evolving organism of both functions of CoQ? (2) What is the mechanism whereby the hydroquinone (antioxidant) form of CoQ (CoQH2) is maintained in high proportion in the various and many membranes in which it resides, and in which an obvious electron transfer mechanism to reduce it is not present? The essentiality of the antioxidative role of CoQH2 will be explored and compared to other primary and secondary antioxidants. Recent evidence implicating the two-electron quinone reductase, DT-diaphorase, in the maintenance of the reduced, antioxidant state of CoQ during the oxidative stress of exhaustive exercise will be presented, and a hypothesis concerning the evolutionary significance of DT-diaphorase will be offered.

During the past year, our understanding of the cellular and molecular processes involved in the generation and control of circadian rhythms has advanced significantly. Progress has been made at the level of the circadian pacemaker mechanism itself, the input pathways that regulate the pacemaker, and the mechanisms by which the pacemaker regulates its various outputs. A common theme underlying all three of these processes is the involvement of transcriptional and translational control. This review is an updated and extended version of a review first published in Current Opinion in Neurobiology 1991, 1:556-561.

Green light (510-565 nm) constitutes a significant portion of the visible spectrum impinging on biological systems. It plays many different roles in the biochemistry, physiology and structure of plants and animals. In only a relatively small number of responses to green light is the photoreceptor known with certainty or even provisionally and in even fewer systems has the chain of events leading from perception to response been examined experimentally. This review provides a detailed view of those biological systems shown to respond to green light, an evaluation of possible photoreceptors and a review of the known and postulated mechanisms leading to the responses.

Classical transmitters are present in all phyla that have been studied; however, our detailed understanding of the process of neurotransmission in these phyla is patchy and has centred on those neurotransmitter receptor mechanisms which are amenable to study with the tools available at the time, for example, high-affinity ligands, tissues with high density of receptor protein, suitable electrophysiological recording systems. Studies also clearly show that many neurones exhibit co-localization of classical transmitters and neuropeptides. However, the physiological implications of this co-localization have yet to be elucidated in the vast majority of examples. The application of molecular biological techniques to the study of neurotransmitter receptors (to date mainly in vertebrates) is contributing to our understanding of the evolution of these proteins. Striking similarities in the structure of ligand-gated receptors have been revealed. Thus, although ligand-gated receptors differ markedly in terms of the endogenous ligands they recognize and the ion channels that they gate, the structural similarities suggest a strong evolutionary relationship. Pharmacological differences also exist between receptors that recognize the same neurotransmitter but in different phyla, and this may also be exploited to further the understanding of structure-function relationships for receptors. Thus, for instance, some invertebrate GABA receptors are similar to mammalian GABAA receptors but lack a modulatory site operated by benzodiazepines. Knowledge of the structure and subunit composition of these receptors and comparison with those that have already been elucidated for the mammalian nervous system might indicate the functional importance of certain amino acid residues or receptor subunits. These differences could also be exploited in the development of new agents to control agrochemical pests and parasites of medical importance. The study of the pharmacology of receptor proteins for neurotransmitters in invertebrates, together with the application of biochemical and molecular biological techniques to elucidate the structure of these molecules, is now gathering momentum. For certain receptors, e.g. the nicotinic receptor, we can expect to have fundamental information on the function of this receptor at the molecular level in both invertebrates and vertebrates in the near future.

Whether animals are vertebrates or invertebrates, the problems raised by the invasion of land are common to all who have succeeded--terrestrial worms, mollusks and crustaceans, arachnids, insects, terrestrial vertebrates. Many physiological traits, although supported by quite different morphological structures, are convergent and related to the environmental characteristics. Thus one is led to put terrestrial animals and aquatic animals belonging to very distantly related phyla, and then suggest an ecophysiological transphyletic division of the animal kingdom.

J.W. von Goethe was a daring and wide-ranging biologist as well as a great playwright. His work was a whole: for him, theory and theatre were both based on keen observation of life. Even 'Faustian' striving, the blind upward urge of life, can be found in significant details of organisms and their evolution, according to Goethe. Such observations cannot be dismissed as sheer poetry. On the contrary, his teleology provides a broad empirical background for the organismic approach in bio-medical science, while exposing inconsistencies in strict reductionist doctrines.

In 1912 Carl von Hess, Professor of Ophthalmology in Munich, published the first comprehensive monograph on color vision in animals. He concluded that fish and all invertebrates are color-blind. At the same time, Karl von Frisch demonstrated that fish and honeybees can see and distinguish colors. The theory of trichromacy (Young-Helmholtz) is valid only for primates and some (e.g., bees) but not all insects. Almost all animals can see colors, and the eyes of some invertebrates contain up to 11 types of spectrally different receptor cells. Most animals - with the exception of mammals and cephalopods - can see ultraviolet and/or far red light. Therefore, many animals perceive more colors than human beings.

(1) Suckling rats were exposed to lead through the milk of their dams who received a diet of 4% lead carbonate and weanling rats were exposed to 2 injections of 5.0 mg Pb2+/100 g body weight. The brains were used to prepare the following homogenate fractions: postmitochondrial supernatant, postmicrosomal supernatant, ribosomes, initiation factors. (2) The postmitochondrial supernatant fractions were tested in vitro for protein synthesizing activity using the incorporation of labelled phenylalanine, and phenylalanyl-tRNA into peptide. The preparations from the lead-exposed rats had a significant reduction in activity. (3) Peptide formation with the brain ribosomes was not changed in the lead-exposed rats. (4) The aminoacyl-tRNA synthetase reaction was significantly reduced and accounted for most of the reduced peptide formation with brain homogenates from lead-exposed rats. (5) The binding of methionyl-tRNAfMet to ribosomes was increased using initiation factor preparations from the brain of lead-exposed rats.

Gerbil pups are attracted to the odors of their maternal nest. This attraction develops by three weeks and is still strong at six weeks, but ceases by nine weeks of age. Removing either the mother's scent gland or her ovaries, a procedure that decreases scent gland size, decreases pup attraction to maternal nest odors. These data suggest that the mother's scent gland is the primary, though not the sole, source of the maternal nest attractants and that ovarian steroids stimulate attractant production. The gradual decline in pup attraction to maternal nest odors with age also parallels the decrease in maternal scent gland size. Pup attraction to nest odors becomes more specific as pups mature. Based on pup responses to odors of other mothers and their young, we suggest that nursing pups approach a species-typical pheromone produced by all lactating females, but that weaning pups imprint on scent gland odors specific to their mother. Other maternal odors and/or odors produced by the pups may also make the nest attractive to the young.