Preliminary evidence of the role of hydrogen peroxide in the degradation of benzo[a]pyrene by a non-white rot fungus Fusarium solani

In order to study the enzymatic mechanisms involved in the successive steps of BaP degradation by a Deuteromycete fungus Fusarium solani, we developed an indirect approach by using inhibitors of enzymes. We used either specific inhibitors of peroxidases (i.e. salicylhydroxamic acid) and of cytochrome P-450 (i.e. piperonyl butoxyde) or inhibitors of both enzymes (i.e. potassium cyanide). Surprisingly, no expected decrease of BaP degradation was observed with most inhibitors tested. On the contrary, more BaP was degraded. Only butylated hydroxytoluene, which acts as a free radical scavenger, inhibited BaP degradation. The inhibition of these enzymes, which use H(2)O(2) as a cosubstrate, might have resulted in an increase of hydrogen peroxide availability in the fungal cultures. This enhancement could induce formation of reactive oxygen species (ROS) which might be the agents that initiate benzo[a]pyrene oxidation. This study proposed a hypothetic alternative metabolic pathway involved in PAH metabolism by Fusarium solani.     

A brief view of known landmarks reorientates path integration in hamsters

 In darkness, hamsters commute between their nest and a feeding site through path integration only, and therefore show cumulative errors in the return direction to the nest. We examined whether a brief presentation of familiar room cues could reset the path integrator. The hamsters could see the room cues either during, or at the end of, the outward journey to the food place, in a conflict situation where motion cues and visual information were set at variance. In both conditions, the animals used mainly visual information to return home. Thus, hamsters can determine their azimuth, and possibly their location, through a visual fix, and can reset their path integrator through the fix. This allows them to update their position during further locomotion in the dark and thus to compute a correct homing vector with respect to a visually induced reference frame. Taking episodic positional fixes may greatly enhance the functional value of path integration. Received: 17 May 2000 / Accepted in revised form: 11 September 2000     

Bringing flood resilience into practice: the FREEMAN project

The recent shift in flood risk management concedes that floods cannot be prevented but the impacts on and vulnerability of the risk prone communities can be reduced. Beyond mere structural defence, an integrated risk management approach deploys a diversified set of measures that moderate the economic and social drivers of risk and improve risk governance. In this context, the concept of resilience gains on importance despite the many challenges that obstruct its implementation in management practice. This paper contributes to tackling these challenges and elaborates on opportunities and bottlenecks to bring resilience into practice based on a review of the flood risk management in three case studies in Europe: Flanders (Belgium), Niedersachsen (Germany) and Calabria (Italy). The paper summarizes insights gained on three components of resilience being – institutional interplay, flood management tools and risk communication. The work that has lead to this paper is done under the FREEMAN project (flood resilience enhancement and management), funded under the 2nd CRUE ERA-Net Funding Initiative.