Transferability of HIV by arthropods supports the hypothesis about transmission of the virus from apes to man

The primate Pan troglodytes troglodytes, a chimpanzee subspecies, has recently been defined as a natural animal host of the human immunodeficiency virus (HIV). Apes are traditionally hunted in Africa and are offered for sale in open-air meat markets. The bloody carcasses are regularly covered with blood-feeding flies, amongst them possibly the stable fly (Stomoxys calcitrans L.), a cosmopolitically occurring biting fly. This fly is the effective vector for the retrovirus causing equine leukemia. According to laboratory experiments, the infectivity of ingested HIV is not reduced in the regurgitates of this fly. These findings are combined to explain the mechanism for a possible primary transmission of HIV from ape to man.     

National and global greenhouse gas dynamics of different forest management and wood use scenarios: a model-based assessment

An increased use of wood products and an adequate management of forests can help to mitigate climate change. However, planning horizons and response time to changes in forest management are usually long and the respective GHG effects related to the use of wood depend on the availability of harvested wood. Therefore, an integral long-term strategic approach is required to formulate the most effective forest and wood management strategies for mitigating climate change.The greenhouse gas (GHG) dynamics related to the production, use and disposal of wood products are manifold and show a complex time pattern. On the one hand, wood products can be considered as a carbon pool, as is the forest itself. On the other hand, an increased use of wood can lead to the substitution of usually more energy-intense materials and to the substitution of fossil fuels when the thermal energy of wood is recovered. Country-specific import/export flows of wood products and their alternative products as well as their processing stage have to be considered if substitution effects are assessed on a national basis.We present an integral model-based approach to evaluate the GHG impacts of various forest management and wood use scenarios. Our approach allows us to analyse the complex temporal and spatial patterns of GHG emissions and removals including trade-offs of different forest management and wood use strategies. This study shows that the contributions of the forestry and timber sector to mitigate climate change can be optimized with the following key recommendations: (1) the maximum possible, sustainable increment should be generated in the forest, taking into account biodiversity conservation as well as the long-term preservation of soil quality and growth performance; (2) this increment should be harvested continuously; (3) the harvested wood should be processed in accordance with the principle of cascade use, i.e. first be used as a material as long as possible, preferably in structural components; (4) waste wood that is not suitable for further use should be used to generate energy. Political strategies to solely increase the use of wood as a biofuel cannot be considered efficient from a climate perspective; (5) forest management strategies to enhance carbon sinks in forests via reduced harvesting are not only ineffective because of a compensatory increase in fossil fuel consumption for the production of non-wooden products and thermal energy but also because of the Kyoto-“cap” that limits the accountability of GHG removals by sinks under Article 3.3 and 3.4, at least for the first commitment period; (6) the effect of substitution through the material and energy use of wood is more significant and sustained as compared with the stock effects in wood products, which tend towards new steady-state flow equilibria with no further increase of C stocks; (7) from a global perspective, the effect of material substitution exceeds that of energy recovery from wood. In the Swiss context, however, the energy recovery from wood generates a greater substitution effect than material substitution.     

?kotoxikologie soll endlich wissenschaftliches Fach werden

Ohne Zusammenfassung     

Chemical oxidation of tetrachloroethene in a fractured saprolite/bedrock aquifer

Two chemical oxidizers, Fenton's Reagent (FR) and sodium permanganate (NaMnO₄), were used to remediate groundwater contaminated by tetrachloroethene (PCE) in a fractured saprolite and bedrock aquifer in Rockville, Maryland. Initial PCE concentrations ranged from 11 to 25,000 μg/L, averaging 8,684 μg/L in March 2000. A total of 28,256 pounds of hydrogen peroxide (as 35 percent solution) and iron catalyst were injected during the FR treatment program. The FR failed to achieve the desired clean‐up goal, after which 11,114 pounds of NaMnO₄ (as 40 percent solution) were diluted to a 20 percent solution and injected into the aquifer. An additional 855 pounds of dilute NaMnO₄ was later injected, which ultimately reduced the original PCE mass by an estimated 95 percent through November 2001. © 2003 Wiley Periodicals, Inc.     

Eine Grenztemperatur beim strahlenchemisch-thermischen Kracken von Paraffin

The Science of Nature -     

Assessing Societal Impacts When Planning Restoration of Large Alluvial Rivers: A Case Study of the Sacramento River Project, California

Studies have shown that ecological restoration projects are more likely to gain public support if they simultaneously increase important human services that natural resources provide to people. River restoration projects have the potential to influence many of the societal functions (e.g., flood control, water quality) that rivers provide, yet most projects fail to consider this in a comprehensive manner. Most river restoration projects also fail to take into account opportunities for revitalization of large-scale river processes, focusing instead on opportunities presented at individual parcels. In an effort to avoid these pitfalls while planning restoration of the Sacramento River, we conducted a set of coordinated studies to evaluate societal impacts of alternative restoration actions over a large geographic area. Our studies were designed to identify restoration actions that offer benefits to both society and the ecosystem and to meet the information needs of agency planning teams focusing on the area. We worked with local partners and public stakeholders to design and implement studies that assessed the effects of alternative restoration actions on flooding and erosion patterns, socioeconomics, cultural resources, and public access and recreation. We found that by explicitly and scientifically melding societal and ecosystem perspectives, it was possible to identify restoration actions that simultaneously improve both ecosystem health and the services (e.g., flood protection and recreation) that the Sacramento River and its floodplain provide to people. Further, we found that by directly engaging with local stakeholders to formulate, implement, and interpret the studies, we were able to develop a high level of trust that ultimately translated into widespread support for the project.