Variation in foraging effort by lactating Antarctic fur seals: response to simulated increased foraging costs

Seasonally breeding predators, which are limited in the time available for provisioning young at a central location, and by the fasting abilities of the young, are likely to maximize energy delivery to the young by maximizing the rate of energy delivery averaged over the whole period of investment. Reduction in food availability or increased foraging costs will alter the optimal behavior of individuals. This study examined the behavioral adaptations of a diving predator, the Antarctic fur seal, to increased foraging costs during lactation. One group of mothers (n=5, treatment) was fitted with additional drag to increase the cost of transport in comparison with a control group (n=8). At the scales of the individual dives, the treatment group made more shorter, shallower (< 30 m) dives. Compensation for slower swimming speeds was achieved by diving at a steeper angle. Overall, diving behavior conformed to several specific theoretical predictions but there were also departures from theory, particularly concerning swimming speed during diving. Diving behavior appears to be adjusted to maximize the proportion of time spent at the bottom of dives. At the scale of diving bouts, no difference was observed between the treatment and control groups in terms of the frequency and duration of bouts and there was also no difference between the two groups in terms of the proportion of time spent diving. At the scale of complete foraging cycles, time taken to return to the pup was significantly longer in the treatment group but there was no difference in the rate of delivery of energy (measured from pup growth rate) to the pups in each group. Since mothers in the treatment group did not use significantly more body reserves, we conclude that behavioral adjustments at the scale of individual dives allowed mothers in the treatment group to compensate for the additional foraging costs. Pup growth rate appears to be less sensitive to the foraging conditions experienced by mothers than foraging trip duration. Received: 14 June 1996 / Accepted after revision: 16 November 1996     

Passive ammonia monitoring in the United States: comparing three different sampling devices

The need for ambient gaseous ammonia (NH(3)) measurements has increased in the last decade as reactive NH(3) concentrations and deposition fluxes show little change even with tightening standards on nitrogen oxides (NO(x)) emissions. Currently, there are several networks developing methods for adding NH(3) measurements in the U.S. Gaseous NH(3) measurements will provide scientists and policymakers data which can be used to estimate ecosystem inputs, validate air quality models including trends and regional variability, and evaluate changes to the environment based on additional emission reduction requirements and estimates of critical nitrogen load exceedances. The passive samplers described in this paper were deployed in duplicate or triplicate and collocated with annular denuders or continuous instruments to determine their accuracy. The samplers assessed included the Adapted Low-Cost Passive High Absorption (ALPHA), Radiello(?), and Ogawa passive samplers. The median relative percent differences (MRPD) between the reference method and passive samplers for the ALPHA, Radiello(?) and Ogawa were -2.4%, -37% and -44%, respectively. The precision between duplicate samplers for the ALPHA and Ogawa samplers, was 7% and 6%, respectively. Triplicate Radiello(?) precision was assessed using the coefficient of variation (CV). The CV for the Radiello(?) samplers was 10%. This article discusses the statistical results from these studies.     

Indicative assessment of the feasibility of Ni and Au phytomining in Australia

Phytomining involves the extraction of metals from solid and liquid substrates using specially selected hyperaccumulating plants. Phytomining is commercially motivated, the objective being to produce a viable metal yield, at production costs low enough to compete with traditional mining techniques, e.g. heap leaching. In this work we assess the technical feasibility of nickel and gold phytomining in Australia by identifying possible sites, plant species most suited to these regions and methods of recovering the metals from the plants once sequestered. We then investigate the economic viability using published technical and financial models. In the near term, phytomining appears most viable where there are comparatively high metal concentrations around existing mines and mineral processing plants, e.g. near tailings dams or smelters, and in recovering metals from low grade ores considered unprofitable using conventional techniques. Phytomining has the added advantage of improving the quality of the land following completion of the operation. The indicative profitability for a Ni phytomine in Australia is predicted to be ～11,500 AU$/ha/harvest, using the hyperaccumulator Berkheya coddii on nickel rich serpentine soils and with energy generation from the harvested biomass. For Au, a profit of ～26,000 AU$/ha/harvest is predicted using induced accumulation (with thiocyanate) with a crop of Brassica juncea coupled with energy generation from the harvested biomass. In both cases, profitability is most sensitive to the metal price and the extractable metal content.     

Blood-based biomarkers in the maternal circulation associated with fetal growth restriction

Fetal growth restriction (FGR) is associated with threefold to fourfold increased risk of stillbirth. Identifying FGR, through its commonly used surrogate—the small-for-gestational-age (SGA, estimated fetal weight and/or abdominal circumference <10th centile) fetus—and instituting fetal surveillance and timely delivery decrease stillbirth risk. Methods available to clinicians for antenatal identification of SGA fetuses have surprisingly poor sensitivity. About 80% of cases remain undetected. Measuring the symphysis-fundal height detects only 20% of SGA fetuses, and even universal third trimester ultrasound detects, at best, 57% of those born SGA. There is an urgent need to find better ways to identify this at-risk cohort. This review summarises efforts to identify molecular biomarkers (proteins, metabolites, or ribonucleic acids) that could be used to better predict FGR. Most studies examining potential biomarkers to date have utilised case-control study designs without proceeding to validation in independent cohorts. To develop a robust test for FGR, large prospective studies are required with a priori validation plans and cohorts. Given that current clinical care detects 20% of SGA fetuses, even a screening test with ≥60% sensitivity at 90% specificity could be clinically useful, if developed. This may be an achievable aspiration. If discovered, such a test may decrease stillbirth.     

‘How corporate social responsibility can be integrated into corporate sustainability: a theoretical review of their relationships’

The notion that corporations are expected to have social and environmental performance standards and practices while meeting their financial and legal obligations is commonly referred to as corporate social responsibility (CSR) or corporate sustainability (CS). Previous studies have discussed whether the two terms are converging or should be used as stand-alone concepts. After reviewing the trends in development of CSR and CS, and the various viewpoints on the relationships between the two, we propose a relationship model to better understand how CSR can be integrated into CS as either a transitional stage or ultimate goal for a corporation. This study aims to provide researchers and practitioners with further insights on the adoption of CSR and CS. The model is intended to provide a plausible view of the relationships between CSR and CS to help to lessen the confusion and ease the communication both between and within these fields.     

Identification of the putative aggregation pheromone components emitted by the European earwig, <Emphasis Type="Italic">Forficula auricularia</Emphasis>

The European earwig, Forficula auricularia is an invasive insect found in many temperate regions of the world and is regarded as an urban and agricultural pest of numerous crops. Several studies have shown that F. auricularia aggregate in large numbers with the use of an aggregation pheromone. However, the identity of compounds which constitute the pheromone remains elusive. Our aim was to isolate and identify the aggregation pheromone used by F. auricularia using both solvent washes of individuals and thermal desorption of substrates exposed to earwigs. Solvent washes of male, female and juvenile earwigs isolated 51 different branched and unbranched alkanes, alkenes and alkadienes. Substrates exposed to aggregating field populations in situ were demonstrated to be attractive to earwigs after less than 24 h of exposure. Analysis of these substrates using thermal desorption and solvent washes showed that hydrocarbons were the only detectable compounds laid down by earwigs on these surfaces. Significant behavioural responses were observed to synthetic blends of the unsaturated hydrocarbons containing (Z)-7-tricosene, (Z)-9-tricosene, (Z)-7-pentacosene and (Z)-9-pentacosene at ≥25 insect equivalents in field-based bioassays. However, behavioural responses to these blends proved inconsistent particularly later in the field season, possibly due to a missing component within the pheromone blend or plasticity in the pheromones production and response.     

Resilience and sustainable development: building adaptive capacity in a world of transformations

Emerging recognition of two fundamental errors underpinning past polices for natural resource issues heralds awareness of the need for a worldwide fundamental change in thinking and in practice of environmental management. The first error has been an implicit assumption that ecosystem responses to human use are linear, predictable and controllable. The second has been an assumption that human and natural systems can be treated independently. However, evidence that has been accumulating in diverse regions all over the world suggests that natural and social systems behave in nonlinear ways, exhibit marked thresholds in their dynamics, and that social-ecological systems act as strongly coupled, complex and evolving integrated systems. This article is a summary of a report prepared on behalf of the Environmental Advisory Council to the Swedish Government, as input to the process of the World Summit on Sustainable Development (WSSD) in Johannesburg, South Africa in 26 August 4 September 2002. We use the concept of resilience--the capacity to buffer change, learn and develop--as a framework for understanding how to sustain and enhance adaptive capacity in a complex world of rapid transformations. Two useful tools for resilience-building in social-ecological systems are structured scenarios and active adaptive management. These tools require and facilitate a social context with flexible and open institutions and multi-level governance systems that allow for learning and increase adaptive capacity without foreclosing future development options.     

Investment in human capital in Africa

Summary The author analyses the problems currently faced by the African continent, recognises six factors which he believes are important in influencing the analysis, and argues that the only secure, renewable asset any country or continent has, is its people. He maintains that people development, rather than the classical economic forms of encouraging development, offers Africa a viable way forward. He then identifies a number of specific issues within such a strategy of investment in human capital.Brian Walker is the President of the International Institute for Environment and Development (IIED), and this address was given at the inaugural meeting of the International Year of Shelter for the Homeless, in London, on 18th April, 1985. A second, earlier, associated address was published inThe Environmentalist 5(3) 167–170.     

APPLICATION OF THE U.S.G.S. DIFFUSION HYDRODYNAMIC MODEL FOR URBAN FLOODPLAIN ANAYSIS1

ABSTRACT: The two-dimensional Diffusion Hydrodynamic Model, DHM, is applied to the evaluation of floodplain depths resulting from an overflow of a leveed river. The environmental concerns of flood protection and high flow velocities can be better studied with the help of the two-dimensional DHM flow model than by use of the one-dimensional modeling techniques. In the test case, some of the predicted flood depth differences between the DHM and the one-dimensional approach (i.e., HEC-2) are found to be significant. Although the DHM generates considerable information, it is easy to use and does not require expertise beyond that required for use of the one-dimensional approaches.