The role of rhizofiltration and allelopathy on the removal of cyanobacteria in a continuous flow system

Environmental Science and Pollution Research - A continuous flow filtration system was designed to identify and quantify the removal mechanisms of Cyanobacteria (Microcystis aeruginosa) by...     

Degradation of endosulfan in a clay soil from cotton farms of western Queensland.

The persistence and degradation of endosulfan isomers and their primary degradation product, endosulfan-sulfate, were studied in a clay soil from cotton farms of western Queensland. Endosulfan degradation in relation to soil moisture, temperature, day and night temperature fluctuation, waterlogging and re-application were studied. The results show that the degradation rates of both endosulfan isomers were greatly affected by changes in soil water content and temperature. Under a high water content-high temperature regime the concentration of alpha-endosulfan in the soil fell rapidly during the first 4 weeks of application, followed by a prolonged period of slower rate of degradation. Alpha endosulfan showed a bi-exponential form of degradation for all water content-temperature experiments except for extremes in both these two factors. In the submerged soils (and also in low-water content, low temperature, non-submerged experiments) no such rapid initial degradation of alpha-endosulfan was observed, and a single first-order rate equation describes the data. Degradation of beta-endosulfan was significantly slower than for the alpha-isomer under all conditions studied. A half-life of more than a year was recorded for the beta-isomer when both water content and temperature were low. The degradation of beta-endosulfan showed no sign of the bi-exponential function observed for alpha-isomer, and a single first order rate equation described the data obtained for each factor studied. Endosulfan-sulfate was the major degradation product in all non-submerged experiments. Its build up in the soil very closely followed the disappearance of alpha-endosulfan. Its highest build-up was in the high water content-low temperature experiments, but its persistence was primarily influenced by soil temperature. Both alpha and beta-isomers, and endosulfan sulfate, persisted longer in the submerged soil. Re-application of endosulfan, and day and night fluctuation of temperature had contrasting effects on the degradation of the two isomers. Both factors slowed down the degradation of alpha-endosulfan and enhanced that of beta-endosulfan, but their net effect was to prolong the overall persistence of this chemical in the soil. Submerged conditions reduced the net formation of endosulfan-sulfate and enhanced its degradation rate.     

Possible chemical causes of skeletal deformities in grey heron nestlings (Ardea cinerea) in North Nottinghamshire, UK

Dead and deformed grey heron (Ardea cinerea) chicks were reported at a large heronry in North Nottinghamshire, UK between 1996 (when systematic visits to the heronry started) and 2002. Many of the birds died for no obvious reason but deformities in others included multiple fractures of the tarsus and tibia and metacarpal bones (angel wings). This study aimed to investigate possible chemical causes of these deformities. Analysis of eggs and nestling tissue for a range of metals showed no levels of concern and no significant differences between unaffected and deformed birds. However, the levels of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) detected in affected heron nestlings in 2002 and in eggs taken from nests in 2003 were sufficiently high to suggest that this may be the underlying cause of the deformities, possibly due to effects on deposition of calcium in bone. Further work is underway to identify where the parent birds of the affected nestlings are feeding and identify the possible source of the pollution.     

Assessing who gains and who loses from natural resource policy: Distributional information and the public participation process

Recent legislation mandates an increased role for public participation in natural resource policy making. This paper presents an operational way to provide those impacted with relevant information and to enable public officials to assess public reaction to proposed policies. The methodology transforms results obtained from a multisector model of income formation and distribution into positive economic measures of distributional impacts. The usefulness of the methodology is illustrated in the context of a policy to increase coal surface mining on public lands.     

Burden or blessing? Expected costs and benefits of being a mentor

We investigated the relationship between anticipated costs and benefits of being a mentor, mentoring experience, and intentions to mentor among a sample of 275 executives. Individuals lacking mentoring experience anticipated greater costs and fewer benefits than experienced individuals. Anticipated costs and benefits were related to intentions to mentor, and this relationship varied by mentoring experience. The results suggest that mentoring may be an intergenerational process. Copyright © 1999 John Wiley & Sons, Ltd.     

Climate change and disaster management

Climate change, although a natural phenomenon, is accelerated by human activities. Disaster policy response to climate change is dependent on a number of factors, such as readiness to accept the reality of climate change, institutions and capacity, as well as willingness to embed climate change risk assessment and management in development strategies. These conditions do not yet exist universally. A focus that neglects to enhance capacity-building and resilience as a prerequisite for managing climate change risks will, in all likelihood, do little to reduce vulnerability to those risks. Reducing vulnerability is a key aspect of reducing climate change risk. To do so requires a new approach to climate change risk and a change in institutional structures and relationships. A focus on development that neglects to enhance governance and resilience as a prerequisite for managing climate change risks will, in all likelihood, do little to reduce vulnerability to those risks.