Consensus among females in their choice of males in the guppy Poecilia reticulata

We studied female guppies from two populations (Trinidad and Jemez Springs, New Mexico) to determine their mating preferences, the degree of consensus among females for particular male phenotypes, and the variation among females for the types of traits they prefer. We recorded the visual responses of 68 Trinidad and 10 Jemez females in paired male trials. The three sexually-selected male traits quantified were the area of orange color and iridescence on the body, and display behavior. Females from the Trinidad population agreed in their choice of males in three of the eight replicates, and this agreement was based on display rate rather than male color patterns. Females from the Jemez population showed no agreement in their preferences of males. Mating preferences of females varied both between populations and among females of a population. In both populations, female preferences were based primarily on courtship intensity and only secondarily on color pattern. However, females from both populations differed in the relative importance of orange color and iridescence. The fact that females differ in criteria for evaluating males has important implications for selection and maintenance of color polymorphisms and for the interactions among multiple secondary sexual traits of males in the guppy. Received: 5 December 1995/Accepted after revision: 7 June 1996     

Gesellschaftlicher Wandel und nachhaltige Entwicklung

Background, aim, and scope In order to assess the effects of social change from the point of view of sustainability the article considers demographic, social and cultural developments. Taking the sectors ‘Building and Housing’, ‘Infrastructure Systems’ and ‘Mobility and Transport’ as examples, it outlines visible trends and describes the possible scope for actions and instruments to achieving sustainably social change. Main features Demographic change, social-cultural change, extent of social change in Schleswig-Holstein, the sectors ‘Building and Housing’, ‘Infrastructure Systems’, and ‘Mobility and Transport’, environmental impact of social change. Results From the point of view of sustainability the essential kriterion is not so much the size of the population in absolute terms as consumer habits, which are subject to numerous influences. One important characteristic of the evolution from the industrial to the post-industrial society is a pluralization of lifestyles, with the associated consumption patterns, in sectors relevant to sustainability. Discussion A diversity of technologies is available for reducing the environmental burden. They influence thermal insulation of buildings, electricity and water sparing, domestic appliances and fuel-efficient vehicles with controlled catalytic converters. The use of these technologies rather depends on cultural and economic trends as well as political decisions than on technical feasibility. Conclusions If no actions occur to counteract them, the effects of social change on the environment will be immense. There will be no ‘demographic benefit’, and neither can the sustainability balance of the postmaterialists be considered more favourable than that of people with a materialistic attitude. Recommendations and perspectives Political groups should address the problems raised by social change, analyze their effects and initiate a comprehensive social process of dialogue and agreement with the players concerned. Quick solutions are not to be expected, since the complexity of the subject, the different interests involved and the large numbers of issues to be regulated require perseverance and a time frame that goes beyond a single legislative period.     

Toward understanding the human dimensions of the rapidly changing arctic system: insights and approaches from five HARC projects

Human dimensions research focuses on the interrelationships between humans and the environment. To date, human dimensions research in arctic regions has concentrated primarily on local events and contexts. As such, it complements analysis elsewhere of adaptation and sustainable development within broad institutional, social, and environmental contexts. This paper reviews five projects from the Human Dimensions of the Arctic System (HARC) initiative, established by the US National Science Foundation in 1997. Common themes and findings are highlighted: climatic variations or change affect societies through interactions with human activities; population dynamics provide key quantitative indicators of social impacts and well being; and specific impacts and responses are the result of complex, context-sensitive interactions. Congruent approaches to the challenges of interdisciplinary research are also identified: multivariate time plots aid the integration of data, retrospective and prospective studies are part of a continuum and reinforce one another, comparative studies are essential for understanding general principles of human dimensions, and arctic residents can play a vital role in research and action.     

Determining distribution coefficients for low cost adsorbents

As with other construction materials, coal fly ash contains trace metals that can leach into the natural environment. As part of a broader effort to encourage appropriate coal combustion product use in infrastructure applications (e.g., road construction, stabilization, and structural fill), this study evaluated traditional and low‐cost adsorbent alternatives for their capacity to attenuate trace metals. Batch sorption tests were used as a preliminary screen for a wide variety of low cost (e.g., steel byproducts, rubber dust, and compost) and innovative materials (e.g., kudzu, biofilm, and pond weed) as well as conventional materials (activated carbon, alumina, and zeolites). The removal rates were demonstrated in this study by observing the calculated distribution coefficient (K_d) which were determined using a program called MATLAB. Limestone and steel byproducts were found to be particularly effective with large K_d values of 15,740, 1,520, and 540 L kg^?1 for cadmium, chromium, and selenium and, for ladle refractory and mill scale, K_d values of 3,910, 670, and 1,760 L kg^?1 were observed. Among the three metals tested for this study, it was observed that most low cost and innovative materials removed cadmium quite efficiently; however, the removal of selenium and chromium depended on the substrate and prevailing pH. In general, these results suggest that alternative materials may have relevance in niche applications where leaching is a concern that can be addressed through enhanced attenuation capacity via blending or layering of adsorbents.     

TIMBER HARVEST IMPACTS ON SMALL HEADWATER STREAM CHANNELS IN THE COAST RANGES OF WASHINGTON1

ABSTRACT: We evaluated changes in channel habitat distributions, particle‐size distributions of bed material, and stream temperatures in a total of 15 first‐or second‐order streams within and nearby four planned commercial timber harvest units prior to and following timber harvest. Four of the 15 stream basins were not harvested, and these streams served as references. Three streams were cut with unthinned riparian buffers; one was cut with a partial buffer; one was cut with a buffer of non‐merchantable trees; and the remaining six basins were clearcut to the channel edge. In the clearcut streams, logging debris covered or buried 98 percent of the channel length to an average depth of 0.94 meters. The slash trapped fine sediment in the channel by inhibiting fluvial transport, and the average percentage of fines increased from 12 percent to 44 percent. The trees along buffered streams served as a fence to keep out logging debris during the first summer following timber harvest. Particle size distributions and habitat distributions in the buffered and reference streams were largely unchanged from the pre‐harvest to post‐harvest surveys. The debris that buried the clearcut streams effectively shaded most of these streams and protected them from temperature increases. These surveys have documented immediate channel changes due to timber harvest, but channel conditions will evolve over time as the slash decays and becomes redistributed and as new vegetation develops on the channel margins.     

Biomarker responses in European eel (Anguilla anguilla) exposed to persistent organic pollutants. A field study in the Vaccarès lagoon (Camargue, France)

A screening of relevant biomarkers was carried out in order to evaluate metabolic and cellular damages in European eels exposed to a non-point source contamination by persistent organic pollutants (POP) such as polycyclic aromatic hydrocarbons (PAH) and organochlorine compounds (OC) in a protected area, the Nature Reserve of Camargue (France). Investigations were focused on metabolic responses including detoxification mechanisms (biotransformation, antioxidant process), energy requirements and enzymatic membrane markers either involved in neuronal conduction (acetylcholinesterase, AChE) or in osmoregulation and energy metabolism (ATPases). The hepatic and muscular glycogen rates seemed to be suitable biomarkers as well as three hepatic activities involved in the protection against oxyradicals: catalase, glutathione peroxidase (SeGPx) and superoxide dismutases (SOD). The muscle and gill ATPases as well as the muscle and brain AChE showed more significant relevance in terms of biomarkers than the biotransformation enzymes: ethoxyresorufine-O-deethylase (EROD) and uridine diphospho-glucuronyl transferase (UDPGT). However, most of these enzymatic activities depend on numerous abiotic factors, which must be taken into account in such a biomarker assessment approach. Our study provides some conclusive elements to approve the use in situ of biomarkers developed from laboratory studies. It also raises a question regarding the location of contaminant impregnation in fish organ, in relation with age, development status or mode of contamination, and its influence on biomarker response. If the relevance of membrane indicators is confirmed, this study provides an original statement of the extent of the ecotoxicological threat for the aquatic species in a protected area, due to the occurrence of POP in the cell membranes.     

Nativ-basierte Grundöle für die Produktion von Kühlschmierstoffen

Aims and Scope

Compared to mineral oil products, cooling lubricants based on fatty acid esters have technological advantages. Moreover, they are more environmentally compatible and make a contribution to a sustainable economy. Nevertheless, they are rarely applied in practice, because of their comparably high price, that is based on raw-material and synthesis costs. Alternatives concerning raw-materials and synthesis pathways are considered and properties of resulting ester products are compared.

Methods

The investigations aimed at three fatty acid-2-ethyl-hexylesters that were synthesized in an enzymatic-catalytic routine based on peanut oil, suet, and waste edible fat and at esters that were conventionally produced from animal and plant fats and 2-ethyl-1-hexanol. Physical properties, fatty acid patterns, contents of free fatty acids, as well as oxidative and hydrolytic stabilities were determined. Thermolysis experiments were performed.

Results

The physical properties of the seven esters, density, viscosity, pourpoint, and flash point, were comparable and gave reason for the assumption, that the products could be used as basis oils in lubricant formulations. Hydrolysis stabilities of the esters were high and thermal stress did not point at high potential of hazardous compounds formation. Especially the enzymatic-catalytically produced esters showed deficits concerning oxidation stabilities and free fatty acid contents.

Outlook

For practice it will be necessary to define minimum qualities for raw-materials and resulting ester oils to be used as lubricant basis oils. Moreover, processes have to be developed, that yield high quality ester products from waste edible and animal fats without loosing the advantage of low-cost raw-materials by high production and refinement costs. Surely, one contribution is the further development of the energy-saving enzymtic alcoholysis for ester production.