Persistence and growth of faecal culturable bacterial indicators in water column and sediments of Vidy Bay, Lake Geneva, Switzerland

The aims of this study was to investigate the persistence and the growth of culturable bacterial indicators (CBI) including total coliforms (TC) and faecal coliforms represented by Escherichia coli, enterococcus (ENT), and aerobic mesophilic bacteria (AMB) in the surface sediments and the water column of Vidy Bay (Lake Geneva, City of Lausanne, Switzerland). The study was carried out for 60 d using microcosms containing Sewage Treatment Plant (STP) e uent and nonsterile water without CBI, as well as contaminated and non-contaminated sediments. The e ects of water temperature and of organic matter associated with sediments on the survival of CBI in the sediments and the water column were observed. The number of CBI colonies in the contaminated sediments of Vidy Bay and in the STP e uent was almost identical in the order of 105–107, 104–106, 103–105, and 104–107 CFU/100 g sediment or /100 mL water for TC, E. coli, ENT, and AMB respectively. A degradation of CBI was observed in the sediments where organic mater content was low and in the water column at a temperature of 10°C after 5 d of experimentation. In addition, a growth of CBI was observed in the sediment which is rich in organic matter at 20°C. The results of this study indicate: (1) the higher concentrations of the CBI observed in di erent points in the water column of Vidy Bay may not be explained only by the recent contribution of the three potential sources of the Bay contamination including STP and the Chamberonne and Flon Rivers, but also by the persistence, removal from sediment and multiplication of CBI in the sediment and water column; (2) the sediment of Vidy Bay constitute a reservoir of CBI and can even support their growth; and (3) the CBI not only survive in sediments, but also can be remobilized and increased in the water column, therefore, it become a permanent microbiological pollution in Vidy Bay.     

Non-thermal production of pure hydrogen from biomass: HYVOLUTION

The objectives and methodology of the EU-funded research project HYVOLUTION devoted to hydrogen production from biomass are reviewed.The main scientific objective of this project is the development of a novel two-stage bioprocess employing thermophilic and phototrophic bacteria, for the cost-effective production of pure hydrogen from multiple biomass feedstocks in small-scale, cost-effective industries. Results are summarised of the work on pretreatment technologies for optimal biodegradation of energy crops and bio-residues, conditions for maximum efficiency in conversion of fermentable biomass to hydrogen and CO₂, concepts of dedicated installations for optimal gas cleaning and gas quality protocols, as well as innovative system integration aimed at minimizing energy demand and maximizing product output.The main technological objective is the construction of prototype modules of the plant which, when assembled, form the basis of a blueprint for the whole chain for converting biomass to pure hydrogen. A brief outline is presented of the progress made towards developing reactors for thermophilic hydrogen production, reactors for photoheterotrophic hydrogen production and equipment for optimal gas cleaning procedures.     

Life cycle inventory analysis of biological hydrogen production by thermophilic and photo fermentation of potato steam peels (PSP)

The environmental impact of hydrogen production in a 2-step fermentation process from potato steam peels was identified. Based on the ISO 14040, ISO 14044, ecoinvent data base and SimaPro 7.1 software, a life cycle inventory analysis was performed. Reflecting the current state of process development, the LCA shows an impact of 4.3 points (pts) which is at least 5.7 times higher than the selected reference technologies regarded as state-of-the-art. Over half (53.5%) of the environmental impact is generated by the use of phosphate in the fermentation processes. A sensitivity analysis shows a potential impact reduction of 65.8% due to recirculation of sewage or reduction of buffer concentration. The analysis also demonstrates that the production of the process ingredients cause 98.3% of the environmental impact. The impact of the process itself is 0.07 pts which is up to 10 times lower than the reference technologies.     

Honeybees modify gustatory responsiveness after receiving nectar from foragers within the hive

Food quality is a relevant characteristic to be transferred within eusocial insect colonies because its evaluation improves the collective foraging efficiency. In honeybees, colony mates could directly acquire this resource characteristic during trophallactic encounters with nectar foragers. In the present study, we focused on the gustatory responsiveness of bees that have unloaded food from incoming foragers. The sugar sensitivity of receiver bees was assessed in the laboratory by using the proboscis extension response paradigm. After unloading, hive bees were captured either from a colony that foraged freely in the environmental surroundings or from a colony that foraged at an artificial feeder with a known sucrose solution. In the first situation, the sugar sensitivity of the hive bees negatively correlated with the sugar concentration of the nectar crops brought back by forager mates. Similarly, in the controlled situation, the highest sucrose concentration the receivers accepted during trophallaxis corresponded to the highest thresholds to sucrose. The results indicate that first-order receivers modify their sugar sensitivity according to the quality of the food previously transferred through trophallaxis by the incoming foragers. In addition, trophallaxis is a mechanism capable of transferring gustatory information in honeybees. Its implications at a social scale might involve changes in the social information as well as in nectar distribution within the colony.     

Anaerobic transformation of four abundant organochlorine pesticide residues (B8-1413, B9-1679, oxychlordane,p,p‵-DDE) in extracts of Antarctic skua eggs by the isolated bacterium Sulfurospirillum multivorans

Residues of halogenated pollutants bioaccumulated in eggs of the south polar skua (Catharacta maccormicki) from the Antarctic were extracted, purified, and fractionated. The target fraction which contained the bulk of the chloropesticides was concentrated and incubated with cell suspensions of the isolated bacterium Sulfurospirillum multivorans (formerly Dehalospirillum multivorans). S. multivorans was previously identified as a good anoxic transformer of several halogenated compounds. The compounds of technical toxaphene 2-endo,3-exo,5-endo,6-exo,8,8,10,10-octachlorobornane (B8-1413, also known as P-26) and 2-endo,3-exo,5-endo,6-exo,8,8,9,10,10-nonachlorobornane (B9-1679, also known as P-50) as well as 1,1-dichloro-2,2-bis(p-chlorophenyl)ethene (p,p′-DDE) and 1-exo,2-exo,4,5,6,7,8,8-octachloro-2,3-exo-epoxy-3a,4,7,7a-tetrahydro-4,7-methanoindene (oxychlordane) were present at a sufficiently high concentration and hence useful for studying the anaerobic transformation by the bacterium. When treated with S. multivorans, B8-1413 and B9-1679 were almost quantitatively transformed within 1 day. For B9-1679, the major metabolite was found to be 2-endo,3-exo,5-endo,6-exo,8,9,10-heptachlorobornane (B7-1001). Compared to the toxaphenes, transformation of oxychlordane and p,p′-DDE was significantly slower. Even after seven days, about 10% of the initial pool was detected in the extracts. 1-chloro-2,2-bis(p-chlorophenyl)ethene (p,p′-DDMU) was identified as a transformation product of p,p′-DDE. The four compounds in this study comprise some of the most persistent chloropesticide residues found in marine birds. In case there is sufficient transformation before they reach the top predators, the bioaccumulative potential can be significantly reduced.     

Calibration for the determination of 19 trace elements in serum and urine

A fast, high-throughput and accurate method was developed for determination of Al, As, Ba, Cd, Co, Cr, Cs, Cu, Fe, Mn, Ni, Pb, Se, U, Zn, Sb, Sn, I and Hg in urine and serum by inductively coupled plasma mass spectrometry. The samples were directly analyzed after 1/20 (v/v) dilution in 0.4% (v/v) HNO₃ and 0.005% Triton X-100. Three calibration modes were tested: aqueous and matrix matching with urine and serum. The accuracy was tested using reference materials of serum, urine and spiking. Results showed that the use of matrix matching calibration reduced the interferences and improved the recoveries for Al, Co, Pb and I in urine. The matrix matching did not affect the results considerably for serum. When serum was spiked with As, Co, Cs, Pb, U, Hg, I, Ba, Al, Cr and Ni, only matrix matching presented good recoveries. Helium was used as a collision cell gas reducing effectively polyatomic interferences for Al, Mn, Cu, Ni, Cr, Zn, As and Fe. Selection of the best internal standard was carried out for each element. The use of diluted HNO₃ improved the limit of detection. Finally, the method was applied successfully in samples of urine from workers occupationally exposed.     

Financial services and disaster risk finance: Examples from the community level

Increased attention has recently been given to the possible role of financial services in the management of natural disaster risk. Local communities have been at the forefront of developing innovative disaster risk finance strategies and implementing risk-oriented incentive programs. In view of increasing risks, including the impacts of climate change, such programs will become more important. This paper examines four models and some recent experiences in using financial services at the community level. The paper offers an overview of advantages and limitations of each model to manage disaster risk in communities. Examples include a federal government initiated scheme of social protection funds, a local government risk reduction scheme, an insurance product provided by a non-governmental organization, and a micro-insurance scheme. Finally, the paper offers some directions about specific ways that the public and private sectors, in collaboration with other partners can improve finance alternatives for disaster management at the community level. It appears that a range of follow-up studies and further dialogue is needed, in order to expand the knowledge on what types of risk finance models can help manage and reduce the financial impacts of natural disasters.     

Behavioral responses to echolocation calls from sympatric heterospecific bats: implications for interspecific competition

Mutual recognition is the product of species coexistence, and has direct effects on survival and reproduction of animals. Bats are able to discriminate between sympatric different heterospecifics based on their echolocation calls, which has been shown both in free-flying and captive bats. To date, however, the factors that may determine the behavioral responses of bats to echolocation calls from sympatric heterospecifics have rarely been tested, especially under well-controlled conditions in captive bats. Hence, we aimed at tackling this question by performing playback experiments (habituation–dishabituation) with three horseshoe bat species within the constant-frequency bat guild, which included big-eared horseshoe bats (Rhinolophus macrotis), Blyth’s horseshoe bats (Rhinolophus lepidus), and Chinese horseshoe bats (Rhinolophus sinicus). We studied the behavioral responses of these three species to echolocation calls of conspecifics, to other two species, and to another heterospecifics bat, Stoliczka’s trident bat (Asellisus stoliczkanus), which also belongs to this guild. We found that the three rhinolophid species displayed a series of distinct behaviors to heterospecific echolocation but few to conspecific calls after habituation, suggesting that they may have been able to discriminate sympatric heterospecific echolocation calls from those of conspecifics. Interestingly, the behavioral responses to heterospecific calls were positively correlated with the interspecific overlap index in trophic niche, whereas call design had only a minor effect. This implies that the behavioral responses of these bats to heterospecific echolocation calls may be related to the degree of interspecific food competition.     

Retrospective monitoring of synthetic musk compounds in aquatic biota from German rivers and coastal areas

The polycyclic musk compounds HHCB (Galaxolide) and AHTN (Tonalide) are commonly used as synthetic fragrances in personal care products and household cleaners. These and other synthetic musk fragrances were quantified in different aquatic samples from the German Environmental Specimen Bank (ESB). While HHCB and AHTN were found in almost all samples, most of the other musk fragrances were detected only in a few samples and mostly at lower concentration levels. Blue mussels from the North Sea showed varying levels of 0.5-1.7 ng g(-1) ww for HHCB and 0.4-2.5 ng g(-1) ww for AHTN (ww, wet weight) in the period from 1986 to 2000, while blue mussels from the Baltic Sea were only slightly contaminated with synthetic musk fragrances. Lipid weight-related concentrations of synthetic musk compounds in blue mussels were higher than in eelpout muscles, bladder wrack and herring gull eggs. In comparison to the marine specimens, muscles of bream from German rivers had higher concentrations of HHCB and AHTN. The ranges of HHCB and AHTN concentrations in bream from the Elbe River were 545-6400 ng g(-1) lw and 48-2130 ng g(-1) lw, respectively (lw, lipid weight; five sampling sites, period 1993-2003). In the Rhine River, HHCB and AHTN levels of bream muscles were highest at the Iffezheim site (up to 9750 ng g(-1) lw HHCB, 1998). Even higher synthetic musk levels were detected in bream from the rivers Saale and Saar. In recent years, levels of both compounds determined in bream from most sampling sites have decreased from maximum values in the 1990s. As the concentrations of AHTN have decreased faster, the ratio of HHCB to AHTN increased from 2-4 in the 1990s to 10-20 in recent years.