The role of ethics in experimental marine biology and ecology

Although most countries have ethical guidelines for research involving human subjects and other sentient animals, the ethical issues associated with field research have received little attention. Most experimental marine biologists and ecologists operate without ethical guidelines or scrutiny, despite intermittent community concern about their activities. We offer suggestions on how marine biologists and ecologists can protect the future of research involving the field collection and experimental manipulation of organisms by developing mechanisms to address community concerns that such research is ethically responsible. We urge experimental marine biologists and ecologists to take pre-emptive initiatives by encouraging: (1) institutional animal ethics committees to broaden their terms of reference to include environmental ethics; (2) scientific societies to develop codes of ethics to guide the environmental research conducted by their members; (3) editorial boards of journals to require the research they publish to conform to an appropriate code of ethics, and (4) management agencies that issue permits for field research to establish an ethics committee to advise them on the ethical issues raised by specific research proposals. We conclude that the resultant administrative burden on scientists would be low but that the penalties of operating without such protection can be high.     

New insights into the molecular interaction of the C-terminal sequence of CXCL4 with fibroblast growth factor-2

Full-length CXCL4 chemokine and a peptide derived from its carboxyl-terminal domain exhibits significant antiangiogenic and anti-tumor activity in vivo and in vitro by interacting with fibroblast growth factor (FGF). In this study we used NMR spectroscopy to characterize at a molecular level the interactions between CXCL4 (47-70) and FGF-2 identifying the peptide residues mainly involved in the contact area with the growth factor. Altogether NMR data point to a major role of the hydrophobic contributions of the C-terminal region of CXCL4 (47-70) peptide in addition to specific contacts established by the N-terminal region through cysteine side chain. The proposed recognition mode constitutes a rationale for the observed effects of CXCL4 (47-70) on FGF-2 biological activity and lays the basis for developing novel inhibitors of angiogenesis.     

Female mice respond to male ultrasonic ‘songs’ with approach behaviour

The ultrasonic vocalizations of mice are attracting increasing attention, because they have been recognized as an informative readout in genetically modified strains. In addition, the observation that male mice produce elaborate sequences of ultrasonic vocalizations (‘song’) when exposed to female mice or their scents has sparked a debate as to whether these sounds are—in terms of their structure and function—analogous to bird song. We conducted playback experiments with cycling female mice to explore the function of male mouse songs. Using a place preference design, we show that these vocalizations elicited approach behaviour in females. In contrast, the playback of pup isolation calls or whistle-like artificial control sounds did not evoke approach responses. Surprisingly, the females also did not respond to pup isolation calls. In addition, female responses did not vary in relation to reproductive cycle, i.e. whether they were in oestrus or not. Furthermore, our data revealed a rapid habituation of subjects to the experimental situation, which stands in stark contrast to other species'' responses to courtship vocalizations. Nevertheless, our results clearly demonstrate that male mouse songs elicit females'' interest.     

Organizer regions in marine colonial hydrozoans

Organizers are specific tissue regions of developing organisms that provide accuracy and robustness to the body plan formation. Hydrozoan cnidarians (both solitary and colonial) require organizer regions for maintaining the regular body patterning during continuous tissue dynamics during asexual reproduction and growth. While the hypostomal organizer of the solitary Hydra has been studied relatively well, our knowledge of organizers in colonial hydrozoans remains fragmentary and incomplete. As colonial hydrozoans demonstrate an amazing diversity of morphological and life history traits, it is of special interest to investigate the organizers specific for particular ontogenetic stages and particular types of colonies. In the present study we aimed to assess the inductive capacities of several candidate organizer regions in hydroids with different colony organization. We carried out grafting experiments on colonial hydrozoans belonging to Leptothecata and Anthoathecata. We confirmed that the hypostome tip is an organizer in the colonial Anthoathecata as it is in the solitary polyp Hydra. We also found that the posterior tip of the larva is an organizer in hydroids regardless of the peculiarities of their metamorphosis mode and colony structure. We show for the first time that the shoot growing tip, which can be considered a key evolutionary novelty of Leptothecata, is an organizer region. Taken together, our data demonstrate that organizers function throughout the larval and polypoid stages in colonial hydroids.     

Experimental investigation of interactions between the temperature field and biofouling in a synthetic treated sewage stream

Biofouling causes significant losses in efficiency in heat exchangers recovering waste heat from treated sewage. The influence of the temperature field on biofouling was investigated using a flat plate heat exchanger which simulated the channels in a plate and frame unit. The test surface was a 316 stainless steel plate, and a solution of Bacillus sp. and Aeromonas sp. was used as a model process liquid. The test cell was operated under co-current, counter-current, and constant wall temperature configurations, which gave different temperature distributions. Biofouling was monitored via changes in heat transfer and biofilm thickness. The effect of uniform temperature on biofouling formation was similar to the effect of uniform temperature on planktonic growth of the organisms. Further results showed that the temperature field, and particularly the wall temperature, influenced the rate of biofouling strongly. The importance of wall temperature suggests that fouling could be mitigated by using different configurations in summer and winter.     

Effects of habitat on growth and shape of contrasting phenotypes of Bembicium vittatum Philippi in the Houtman Abrolhos Islands,Western Australia

Translocation experiments were used to test the effect of habitat on growth and shape of three contrasting phenotypes of Bembicium vittatum: dwarf, highly domed snails from an usually dry tidal pond; large, moderately domed snails from a sheltered, regularly inundated pond; and relatively flat snails from a vertical, exposed shore. Snails from both ponds grew nearly twice as fast in the wet pond as in the dry pond, indicating a high degree of plasticity of growth. Associated with these changes in growth rates was convergence of shape. Under conditions of rapid growth, the dwarf snails became relatively flatter, and hence more similar to the native snails at that site. These results indicate that the dwarf phenotype is largely a plastic stunting in response to conditions of little submersion time. The snails from the exposed shore also grew faster in the sheltered, wet pond than at their native site. However, they not only retained their flat shape, but actually became flatter (and hence divergent from the pond snails) when grown in the pond. Thus, variation in shell shape was due to interactions between source population and a common plastic association of flatter growth profile with more rapid growth. Previous experiments had demonstrated high heritability of the flat phenotype, while the present results show that the expression of the genetically different types is affected substantially by the conditions of growth, and that phenotypic differences among populations may either overestimate or underestimate the underlying genetic differences. This unpredictability of the relationship between variation in shell form and its underlying genetic basis complicates interpretations of geographical variation or palaeontological sequences based on shell form.     

Systematic designs for experiments with mixtures

In this paper systematic designs for experiments with mixtures are developed. The plan of analysis of the experiment is discussed for a quadratic model of SCHEFF É (1958) for q-component mixture with orthogonal polynomials of third degree describing the time trends.     

Artificial injury experiments on the damaging effect of Leucoptera malifoliella on apple trees

In 1986 and 1987 defoliation experiments on the apple cultivar Herma were performed to simulate the occurrence of Leucoptera malifoliella Costa. Those model experiments were based on investigations on the mine size of Leucoptera malifoliella and yield loss on infested and tagged trees. Defoliation carried out by hand showed that heavy leaf loss reduced fruit number. Insufficient nutrient supply due to reduced leaf area and a consequently smaller leaf-fruit ratio led to a decrease in mean fruit size and total yield. Heavy leaf loss had also an adverse effect on fruit quality components (dry matter substance, viscosity, total sugar and acid content of fruit juice). This was finally reflected in sensory evaluation criteria. Heavy leaf losses also influenced blossom bud differentiation in the blossom set of the following year. Both number of inflorescences and number of blossoms per inflorescence were reduced. The evaluation of the extent of damage of L. malifoliella was based on previous investigations on reduced leaf area. For L. malifoliella a mean mine size of 0.96 cm² was found. This corresponds to a 4.2% loss of leaf area.The leaf-fruit ratio is of special importance for the evaluation of the extent of damage of leaf-damaging pests and was used to derive injury threshold ranges for L. malifoliella. Previous investigations on L. malifoliella infestations and the results from the artificial defoliation experiments enabled the determination of preliminary flexible injury thresholds. Depending on leaf-fruit ratio, yield level, and leaf miner generation, the thresholds vary between 0.1–2.5 eggs and mines per leaf.     

Model Trials for Phytoremediation of Hydrocarbon-Contaminated Sites by the Use of Different Plant Species

In order to further the development of plant-based remediation of sites contaminated by carbo-chemical and petro-chemical industries, the penetration of the roots of Phragmites australis in contaminated soil substrate was studied in model trials. The series of experiments contained model substrate with firm bitumen and tar. In terms of the level of root penetration, the roots and rhizomes penetrated equally through the middle of the pot and at the edges as well as coming up through the bottom. There were differences between the density of the root systems in the topsoil of the two variations, with the roots in the sample with a 3.5 -cm bitumen layer being more dense. The experiment also showed that shallow rooting plants can penetrate thick barriers and are suitable for planting in contaminated areas. In the subsoil zone, which contained many roots, a reduction of up to 85% in the MOH content was observed. In a second series of long-term pot experiments, the stimulation of hydrocarbon remediation by Phragmites australis, Alnus glutinosa, and Robinia pseudoacacia was studied. In the subsoil zone, which contained many roots, a reduction of up to 64% in the hydrocarbon content was determined. In the comparison between the cropped and noncropped treatments, the decontamination ratio was up to 40% higher in the cropped pots than in the pots without plants. For a determination of microbial activity, two enzymes (catalase, ß-glucosidase) and microbial biomass were measured. Variants with plants showed higher microbial activities than uncropped pots. By increasing “biostimulation,” pollution and also the leaching of pollutants can be reduced.