21,000 Years of Ethiopian African monsoon variability recorded in sediments of the western Nile deep-sea fan

The Nile delta sedimentation constitutes a continuous high-resolution record of Ethiopian African monsoon (EAM) regime intensity. Multi-proxy analyses performed on hemipelagic sediments deposited on the Nile deep-sea fan allow the quantification of the Saharan aeolian dust and the Blue/White Nile River suspended matter frequency fluctuations during the last 21,000 years. The radiogenic strontium and neodymium isotopes, clay mineralogy, elemental composition and preliminary palynological analyses reveal large changes in source components, oscillating between a dominant aeolian Saharan contribution during the Last Glacial Maximum (LGM) and the late Holocene (~4,000–2,000 years), a dominant Blue/Atbara Nile River contribution during the early Holocene (15,000–8,000 years) and a probable White Nile River contribution during the middle Holocene (8,000–4,000 years). The following main features are highlighted: (1) The rapid shift from the LGM arid conditions to the African Humid Period (AHP) started at about 15,000 years. The AHP extends until 8,000 years, and we suggest that the EAM maximum between 15,000 and 8,000 years is responsible for a larger Blue/Atbara Nile sediment load and freshwater input into the eastern Mediterranean Sea. (2) The transition between the AHP and the arid late Holocene is gradual and occurs in two main phases between 8,400–6,500 years and 6,500–3,200 years. We suggest that the main rain belt shifted southward from 8,000 to ~4,000 years and was responsible for progressively reduced sediment load and freshwater input into the eastern Mediterranean Sea. (3) The aridification along the Nile catchments occurred from ~4,000 to 2,000 years. This dry period, which culminates at 3,200 year, seems to coincide with a re-establishment of increased oceanic primary productivity in the western Mediterranean Sea. Such a pattern imposes a large and rapid northward shift of the rain belt over the Ethiopian highlands (5–15°N) since 15,000 years. Precipitation over Ethiopia increased from 15,000 to 8,000 years. It was followed by a gradual southward shift of the rain belt over the equator from 8,000 to 4,000 years and finally a large shift of the rain belt south the equator between 4,000 and 2,000 years inducing North African aridification. We postulate that the decrease in thermohaline water Mediterranean circulation could be part of a response to huge volumes of freshwater delivered principally by the Nile River from 15,000 to 8,000 years in the eastern Mediterranean.     

Sea-Level Rise Risk Communication: Public Understanding,Risk Perception,and Attitudes about Information

We present the results of a study using a document-based evaluation method to better understand how residents in vulnerable coastal areas respond to risk communications about sea-level rise (SLR) and to determine whether communications localized for specific populations improve reception. Similar to climate change communication, SLR risk communication presents challenges involving complex science, uncertainty, invisibility, and politicization. To be comprehensible and persuasive, risk messages must be appropriately framed and visually compelling and must take into account risk perceptions and diverse viewpoints. Our approach involves assessing people's encounters with actual risk messages to determine their reactions and responses. Participants in this study had difficulty understanding information and expressed attitudes including fear, fatalism, skepticism, and loss. SLR risks were also perceived as both temporally and spatially distant, creating a challenge for communicators trying to convey a sense of urgency. We conclude by considering the implications of audience-focused research for SLR risk communication.     

Pilot-scale biopesticide production by Bacillus thuringiensis subsp. kurstaki using starch industry wastewater as raw material

Pilot-scale Bacillus thuringiensis based biopesticide production (2000 L bioreactor) was conducted using starch industry wastewater (SIW) as a raw material using optimized operational parameters obtained in 15 L and 150 L fermenters. In pilot scale fermentation process the oxygen transfer rate is a major limiting factor for high product yield. Thus, the volumetric mass transfer coefficient (K_La) remains a tool to determine the oxygen transfer capacity [oxygen utilization rate (OUR) and oxygen transfer rate (OTR)] to obtain better bacterial growth rate and entomotoxicity in new bioreactor process optimization and scale-up. This study results demonstrated that the oxygen transfer rate in 2000 L bioreactor was better than 15 L and 150 L fermenters. The better oxygen transfer in 2000 L bioreactor augmented the bacterial growth [total cell (TC) and viable spore count (SC)] and delta-endotoxin yield. Prepared a stable biopesticide formulation for field use and its entomotoxicity was also evaluated. This study result corroborates the feasibility of industrial scale operation of biopesticide production using starch industry wastewater as raw material.     

Variation of stabilised,microbial and biologically active carbon and nitrogen in soil under contrasting land use and agricultural management practices

Land use and agricultural practices modify both the amounts and properties of C and N in soil organic matter. In order to evaluate land use and management-dependent modifications of stable and labile C and N soil pools, (i). organic C and total N content, (ii). microbial (C(mic)) and N (N(mic)) content and (iii). C and N mineralisation rates, termed biologically active C and N, were estimated in arable, grassland and forest soils from northern and southern Germany. The C/N-ratios were calculated for the three levels (i)-(iii) and linked to the eco-physiological quotients of biotic-fixed C and N (C(mic)/C(org), N(mic)/N(t)) and biomass-specific C and N mineralisation rate (qCO(2), qN(min)). Correlations could mainly be determined between organic C, total N, C(mic), N(mic) and C mineralisation for the broader data set of the land use systems. Generally, the mineralisation activity rate at 22 degrees C was highly variable and ranged between 0.11 and 17.67 microg CO(2)-C g(-1) soil h(-1) and -0.12 and 3.81 microg (deltaNH(4)(+)+deltaNO(3)(-))-N g(-1) soil h(-1). Negative N data may be derived from both N immobilisation and N volatilisation during the experiments. The ratio between C and N mineralisation rate differed significantly between the soils ranging from 5 to 37, and was not correlated to the soil C/N ratio and C(mic)/N(mic) ratio. The C/N ratio in the 'biologically active' pool was significantly smaller in soils under conventional farming than those under organic farming systems. In a beech forest, it increased from the L, Of to the Ah horizon. The biologically active C and N pools refer to the current microbial eco-physiology and are related to the need for being C and N use efficient as indicated by metabolic qCO(2) and qN(min) quotients.     

Environmental evaluation of transfer and treatment of excess pig slurry by life cycle assessment

Slurry management is a central topic in the agronomic and environmental analysis of intensive livestock production systems. The objective of this study is to compare the environmental performance of two scenarios of collective slurry management for the disposal of excess nitrogen from animal manure. The scenarios are the transfer of slurry and its injection to crop land, and the treatment of slurry in a collective biological treatment station. The study is based on a real case in the West of France, where a group of farmers is developing a collective plan for the disposal of almost 7000 m(3) of excess pig slurry. The evaluation is carried out by Life Cycle Assessment, where emissions and resource consumption are quantified and aggregated into four environmental impact categories: eutrophication, acidification, climate change, and non-renewable energy use. Ammonia emitted is the most important contributor to acidification and eutrophication, while methane contributes most to climate change. Both ammonia and methane are mostly emitted during the storage of slurry and, in the case of the treatment scenario, also during composting the solid fraction of the slurry. The two management strategies are similar with respect to climate change, whereas eutrophication and acidification are twice as large for treatment relative to transfer. Electricity needed for the treatment process is the main contributor to non-renewable energy use for the treatment scenario, while the transfer scenario represents a net energy saving, as energy saved by the reduction of mineral fertiliser use more than compensates for the energy needed for transport and injection of slurry. The overall environmental performance of transfer is better than that of treatment, as it involves less acidification, eutrophication and non-renewable energy use. The method employed and the results obtained in this study can provide elements for a transparent discussion of the advantages and disadvantages of contrasting excess slurry management scenarios as well as the identification of the main aspects determining their environmental performance.     

A discourse-analytical perspective on sustainability assessment: interpreting sustainable development in practice

Sustainable development is a ubiquitously used concept in public decision-making: it refers to an ideal vision of global society where human development and environmental quality go hand in hand. Logically, any decision-supporting process aiming at facilitating and steering society toward a sustainable future then seems desirable. Assessing the sustainability of policy decisions is, however, influenced by what sustainable development is believed to entail, as different discourses coexist under the umbrella of the sustainable development meta-discourse. This paper proposes a typology of sustainable development discourses, and, subsequently, applies a discourse-analytical lens on two practical cases of sustainability assessment in different institutional and geographical contexts (in Belgium and in Benin). The results indicate that sustainability assessments tend to be influenced mainly by the consensual ‘sustainable development as integration’ discourse, while also providing a forum for dialogue between different discourses. The results shed light on context-specific discursive and institutional dynamics for the development and application of sustainability assessment. Acknowledging these dynamics as well as sustainable development’s inherent interpretational limits can lead to an improved use of sustainable development as a decision-guiding strategy.     

Mussel transplantation and biomarkers as useful tools for assessing water quality in the NW Mediterranean

Mussels, coming from an aquaculture farm located in a clean open bay, were transplanted to several stations of the bays of Nice and Cannes (NW Mediterranean) including a reference site for one month at three periods. Several biomarkers: activities of glutathione S-transferase (GST; exposure to organics), of catalase (exposure to oxidative stress) and of acetylcholinesterase (inhibited by some pesticides) and the lipid peroxidation (thiobarbituric acid reactive substances: TBARS) were measured in transplanted mussels. Cd, Cu and Zn concentrations were also measured as well as their condition index. The results demonstrated some seasonal variations in GST and catalase activities with higher levels in June compared to October. The condition index was also higher in June than in October. Principal component analyses performed with the whole set of data allowed to separate stations or groups of stations according to their responses. The mussels from the harbour of Nice were characterized by high TBARS levels and catalase activity in October 1999 whereas in the harbour of Cannes, animals presented very high copper concentrations and GST activities in June 2000. At the reference site, mussels generally presented low enzymatic activities (except AChE activity) and peroxidation levels and low heavy metal concentrations.     

Continuous Emission Monitoring: Objectives and Requirements

Regulations were recently proposed by the Environmental Protection Agency which, when promulgated, will require existing and new sources within certain specified source categories to install, operate, and maintain continuous emission monitoring systems. Major comments received on these proposed regulations are discussed as are the overall benefits that can be derived from the utilization of continuous emission monitoring systems.