Experimental study on the thermal oxidation of 2-chlorophenol in air over the temperature range 450-900 degrees C

The thermal oxidation of 2-chlorophenol (2-CP) in air was investigated using a perfectly stirred reactor at 1 atm over the temperature range 450–900 °C. The relative concentration of 2-CP was 1000 ppmV (equivalence ratio Φ = 0.03). About fifty organic products were identified as trace species. The concentration profiles of 2-CP, carbon oxides as well as those of seventeen major organic intermediates and six non-to-lower chlorinated dioxins and furans were presented as a function of temperature for a residence time of 2 s. The most abundant intermediate products were carbon monoxide, 2 H-pyran-2-one, chlorobenzene, 4-cyclopenten-1,3-dione, phenol, benzofuran, 2-chlorohydroquinone and 2-indanone. These concentration profiles have revealed that temperatures of at least 900 °C were needed to completely oxidize 2-CP, CO and all other organic byproducts to carbon dioxide. Reaction pathways accounting for the formation of most observed products are proposed.     

Dispersal depression with habitat fragmentation in the bog fritillary butterfly

Habitat fragmentation is expected to impose strong selective pressures on dispersal rates. However, evolutionary responses of dispersal are not self-evident, since various selection pressures act in opposite directions. Here we disentangled the components of dispersal behavior in a metapopulation context using the Virtual Migration model, and we linked their variation to habitat fragmentation in the specialist butterfly Proclossiana eunomia. Our study provided a nearly unique opportunity to study how habitat fragmentation modifies dispersal at the landscape scale, as opposed to microlandscapes or simulation studies. Indeed, we studied the same species in four landscapes with various habitat fragmentation levels, in which large amounts of field data were collected and analyzed using similar methodologies. We showed the existence of quantitative variations in dispersal behavior correlated with increased fragmentation. Dispersal propensity from habitat patches (for a given patch size), and mortality during dispersal (for a given patch connectivity) were lower in more fragmented landscapes. We suggest that these were the consequences of two different evolutionary responses of dispersal behavior at the individual level: (1) when fragmentation increased, the reluctance of individuals to cross habitat patch boundaries also increased; (2) when individuals dispersed, they flew straighter in the matrix, which is the best strategy to improve dispersal success. Such evolutionary responses could generate complex nonlinear patterns of dispersal changes at the metapopulation level according to habitat fragmentation. Due to the small size and increased isolation of habitat patches in fragmented landscapes, overall emigration rate and mortality during dispersal remained high. As a consequence, successful dispersal at the metapopulation scale remained limited. Therefore, to what extent the selection of individuals with a lower dispersal propensity and a higher survival during dispersal is able to limit detrimental effects of habitat fragmentation on dispersal success is unknown, and any conclusion that metapopulations would compensate for them is flawed.     

Balkanized Research in Ecological Engineering Revealed by a Bibliometric Analysis of Earthworms and Ecosystem Services

Energy crisis, climate changes, and biodiversity losses have reinforced the drive for more ecologically-based approaches for environmental management. Such approaches are characterized by the use of organisms rather than energy-consuming technologies. Although earthworms are believed to be potentially useful organisms for managing ecosystem services, there is actually no quantification of such a trend in literature. This bibliometric analysis aimed to measure the evolution of the association of “earthworms” and other terms such as ecosystem services (primary production, nutrient cycling, carbon sequestration, soil structure, and pollution remediation), “ecological engineering” or “biodiversity,” to assess their convergence or divergence through time. In this aim, we calculated the similarity index, an indicator of the paradigmatic proximity defined in applied epistemology, for each year between 1900 and 2009. We documented the scientific fields and the geographical origins of the studies, as well as the land uses, and compare these characteristics with a 25 years old review on earthworm management. The association of earthworm related keywords with ecosystem services related keywords was increasing with time, reflecting the growing interest in earthworm use in biodiversity and ecosystem services management. Conversely, no significant increase in the association between earthworms and disciplines such as ecological engineering or restoration ecology was observed. This demonstrated that general ecologically-based approaches have yet to emerge and that there is little exchange of knowledge, methods or concepts among balkanized application realms. Nevertheless, there is a strong need for crossing the frontiers between fields of application and for developing an umbrella discipline to provide a framework for the use of organisms to manage ecosystem services.     

Wintering Waterbirds and Recreationists in Natural Areas: A Sociological Approach to the Awareness of Bird Disturbance

Disturbance to wintering birds by human recreational activities has become a major concern for managers of many natural areas. Few studies have examined how recreationists perceive their effects on birds, although this impacts their behavior on natural areas. We surveyed 312 users on two coastal ornithological sites in Brittany, France, to investigate their perception of the effects of human activities on wintering birds. The results show that the awareness of environmental issues and knowledge of bird disturbance depends on the socioeconomic characteristics of each user group, both between the two sites and within each site. Results also indicate that, whatever the site and the user group, the vast majority of the respondents (77.6 %) believed that their own presence had no adverse effects on the local bird population. Various arguments were put forward to justify the users’ own harmlessness. Objective information on recreationists’ awareness of environmental issues, and particularly on their own impact on birds, is important to guide managers in their choice of the most appropriate visitor educational programs. We recommend developing global but also specific educational information for each type of user to raise awareness of their own impact on birds.     

Sonochemical reduction of the antioxidant activity of olive mill wastewater

The use of ultrasonic irradiation to reduce the antioxidant activity of olive oil mill wastewaters (OMWs) originating from two-phase and three-phase decanters was examined. Sonication of diluted OMW samples was conducted at ultrasonic frequencies of 24 and 80 kHz, an applied power varying between 75 and 150 W, and liquid bulk temperatures varying between 25 and 60 degrees C. At the conditions in question, the reduction in antioxidant activity was found to increase with decreasing temperature and increasing power and frequency. Addition of NaCl in the samples also appeared to enhance reduction. Antioxidant activity of OMW samples was assessed using the recently developed Co(II)/ethylenediaminetetraacetic acid (EDTA)-induced luminol chemiluminescence analytical protocol, while the total phenolic load was measured according to the Folin-Ciocalteu method.     

Phytoextraction of Pb and Cd by the Mediterranean saltbush (Atriplex halimus L.): metal uptake in relation to salinity

Background, aim, and scope  

The success of phytoextraction depends upon the identification of suitable plant species that hyperaccumulate heavy metals and produce large amounts of biomass using established agricultural techniques. In this study, the Mediterranean saltbush Atriplex halimus L., which is a C4 perennial native shrub of Mediterranean basin with an excellent tolerance to drought and salinity, is investigated with the main aim to assess its phytoremediation potential for Pb and Cd removal from contaminated soils. In particular, the influence of soil salinity in metal accumulation has been studied as there is notable evidence that salinity changes the bioavailability of metals in soil and is a key factor in the translocation of metals from roots to the aerial parts of the plant.     

Ethical Issues Related to Food Sector Evolution in Developing Countries: About Sustainability and Equity

After a century of major technicaladvance, essentially achieved by and for theindustrialized countries, the evolution of thefood sector in southern countries should nolonger be thought of in terms of a ``headlongpursuit.'' In the present context of demographicgrowth, urbanization, poverty and disparities,environmental degradation, and globalization oftrade, new priorities have emerged, and newethical questions have been raised, mainlyrelated to sustainability and equity. Thispaper analyses these ethical concerns in thefollowing terms: can the model of food sectordevelopment initiated by the industrializedcountries be applied to the entire world on asustainable and equitable basis, given theeffects of this development with regard to theenergy consumed, the changes in dietarybehavior and related nutritional problems, thenew demands in terms of food safety, thequestions of biodiversity, ownership ofknowledge, cultural identities, gender issues,and Man's relationship to food and Nature?     

Benefits of systems thinking for a human and organizational factors approach to safety management

This paper highlights the value of systems theory and its application to human and organizational factors (HOF). HOF specialists consider multiple systems characteristics in their analyses but are often unaware of the relevant theory applied in their analysis. We argue that a structured effort to take key systems characteristics into account in HOF practice would increase the depth and breadth of safety management analyses and help HOF specialists to act more effectively on industrial socio-technical systems. First, the paper identifies the following seven system theory characteristics: constitution, multi-axis representation, limit, emergence, variety, coherence, and causal interaction, which are then illustrated with examples from the HOF field. Finally, we discuss the two main benefits of integrating system thinking in a HOF approach to safety management: (1) an improved understanding of the inner workings of an industrial socio-technical system; and (2) a compendium or a reference to guide for decision-making and the implementation of actions within the industrial socio-technical systems.     

A bee in the corridor: centering and wall-following

In an attempt to better understand the mechanism underlying lateral collision avoidance in flying insects, we trained honeybees (Apis mellifera) to fly through a large (95-cm wide) flight tunnel. We found that, depending on the entrance and feeder positions, honeybees would either center along the corridor midline or fly along one wall. Bees kept following one wall even when a major (150-cm long) part of the opposite wall was removed. These findings cannot be accounted for by the “optic flow balance” hypothesis that has been put forward to explain the typical bees’ “centering response” observed in narrower corridors. Both centering and wall-following behaviors are well accounted for, however, by a control scheme called the lateral optic flow regulator, i.e., a feedback system that strives to maintain the unilateral optic flow constant. The power of this control scheme is that it would allow the bee to guide itself visually in a corridor without having to measure its speed or distance from the walls.