Fungal Degradation of Poly(l-lactide) in Soil and in Compost

The biodegradability of polymers by microorganisms is generally studied in a real environment that contains a natural mixture of fungi and bacteria. The present research mainly focused on the purely fungal degradation of poly(l-lactide), PLLA, to enclose the part of fungi in a real process of biodegradation and to understand the kinetics of biodegradation. Respirometric tests were realized in soil at 30?°C, and in compost at 30?and 58?°C. Results indicated that temperature is the predominant parameter governing the fungal degradation of PLLA. Moreover, in real compost, the biodegradation kinetics of the PLLA revealed a synergy between bacteria and fungi. The curves of PLLA and cellulose biodegradation were modeled by Hill sigmo?d. Fungal degradation was completed by investigating the physical and the chemical properties of the polymer during the process of degradation using several analytical methods such as matrix assisted laser desorption ionization-time of fly spectroscopy, infrared spectroscopy, size exclusion chromatography, and differential scanning calorimetry. These experiments led to a better understanding of the various stages of fungal degradation of PLLA: hydrolysis as well as mineralization. Furthermore, metabolizing products (by-products) of PLLA was investigated also.     

Participatory diagnosis in urban planning: proposal for a learning process based on geographical information

Urban planning involves compromise between the diverse and often contradictory issues supported by the different stakeholders. The literature generally agrees on the need to broaden the participation base to overcome this difficulty. However, participation should not be limited to problem solving, but should also take place in the problem setting phase. This paper proposes a participatory diagnosis process for structuring the problem setting phase. We describe an experiment in a participatory diagnosis conducted with the residents of a Geneva neighborhood. The experiment began by identifying the residents' concerns, which were then reformulated under broader issues. Some 20 spatial indicators were built using GIS tools, and were then applied in a second phase of resident consultations to assess the relative importance of each issue. The ensuing priority issues formed the core of the diagnosis. The approach emphasized comparison between the daily experiences of residents and so-called official information (i.e. census tract, traffic measurement, and so on). The residents were therefore involved in a learning process that allowed them to consolidate or modify their opinions. The process led to the emergence of a clearly defined collective awareness that supplanted individual aspirations.     

Insight into the growth dynamics and systematic affinities of the Late Cretaceous Gargantuavis from bone microstructure

Enigmatic avialan remains of Gargantuavis philoinos from the Ibero-Armorican island of the Late Cretaceous European archipelago (Southern France) led to a debate concerning its taxonomic affinities. Here, we show that the bone microstructure of Gargantuavis resembles that of Apteryx, the extinct emeids and Megalapteryx from New Zealand, and indicates that like these slow-growing terrestrial birds, it took several years to attain skeletal maturity. Our findings suggest that the protracted cyclical growth in these ornithurines may have been in response to insular evolution.     

Double-outlet right ventricle with absent left ventricle and mitral atresia in a fetus with a deletion 22q12

Interstitial deletions of chromosomal region 22q12 are rare. We report the prenatal diagnosis of a de novo interstitial deletion 22q12. The fetus was karyotyped because of a complex cardiac anomaly. Conventional and molecular cytogenetics showed a female karyotype with a de novo pericentric inversion of one chromosome 22 associated with a deletion of the chromosomal region 22q12 leading to a partial monosomy 22q12. At autopsy, the fetus showed double-outlet right ventricle (DORV) with absent left ventricle and mitral atresia. This observation suggests that one or several genes for the early looping step of heart development may reside in chromosomal region 22q12. Further studies are needed to identify these genes, and to search microdeletions of 22q12 region in patients with DORV. Copyright © 2004 John Wiley & Sons, Ltd.     

MSWI boiler fly ashes: magnetic separation for material recovery

Nowadays, ferrous materials are usually recovered from Municipal Solid Waste Incineration (MSWI) bottom ash by magnetic separation. To our knowledge, such a physical technique has not been applied so far to other MSWI residues. This study focuses thus on the applicability of magnetic separation on boiler fly ashes (BFA). Different types of magnet are used to extract the magnetic particles. We investigate the magnetic particle composition, as well as their leaching behaviour (EN 12457-1 leaching test). The magnetic particles present higher Cr, Fe, Mn and Ni concentration than the non-magnetic (NM) fraction. Magnetic separation does not improve the leachability of the NM fraction. To approximate industrial conditions, magnetic separation is also applied to BFA mixed with water by using a pilot. BFA magnetic separation is economically evaluated. This study globally shows that it is possible to extract some magnetic particles from MSWI boiler fly ashes. However, the magnetic particles only represent from 23 to 120 g/kg of the BFA and, though they are enriched in Fe, are composed of similar elements to the raw ashes. The industrial application of magnetic separation would only be profitable if large amounts of ashes were treated (more than 15 kt/y), and the process should be ideally completed by other recovery methods or advanced treatments.     

Oxygen isotope fractionation between bird bone phosphate and drinking water

Oxygen isotope compositions of bone phosphate (δ¹⁸O_p) were measured in broiler chickens reared in 21 farms worldwide characterized by contrasted latitudes and local climates. These sedentary birds were raised during an approximately 3 to 4-month period, and local precipitation was the ultimate source of their drinking water. This sampling strategy allowed the relationship to be determined between the bone phosphate δ¹⁸O_p values (from 9.8 to 22.5‰ V-SMOW) and the local rainfall δ¹⁸O_w values estimated from nearby IAEA/WMO stations (from ?16.0 to ?1.0‰ V-SMOW). Linear least square fitting of data provided the following isotopic fractionation equation: δ¹⁸O_w = 1.119 (±0.040) δ¹⁸O_p ? 24.222 (±0.644); R ² = 0.98. The δ¹⁸O_p–δ¹⁸O_w couples of five extant mallard ducks, a common buzzard, a European herring gull, a common ostrich, and a greater rhea fall within the predicted range of the equation, indicating that the relationship established for extant chickens can also be applied to birds of various ecologies and body masses. Applied to published oxygen isotope compositions of Miocene and Pliocene penguins from Peru, this new equation computes estimates of local seawater similar to those previously calculated. Applied to the basal bird Confuciusornis from the Early Cretaceous of Northeastern China, our equation gives a slightly higher δ¹⁸O_w value compared to the previously estimated one, possibly as a result of lower body temperature. These data indicate that caution should be exercised when the relationship estimated for modern birds is applied to their basal counterparts that likely had a metabolism intermediate between that of their theropod dinosaur ancestors and that of advanced ornithurines.     

Importance of heterotrophic planktonic communities in a mussel culture environment: the Grande Entrée lagoon,Magdalen Islands (Québec,Canada)

Mussel culture in coastal environments relies on the availability of food of sufficient quality and quantity. Both to determine this availability and to examine impacts that this aquaculture practice may have on the environment, it is important to have good knowledge of the type of plankton communities present in aquaculture sites. It is usually thought that phytoplankton make up the bulk of mussel diet in many of these sites. Here we show that the Grande-Entrée lagoon [Magdalen Islands, Gulf of St Lawrence (GSL), Canada], where commercial mussel culture has been on-going since 1980, differs from this pattern. Heterotrophic protists dominate for most of the summer-early fall season (apart from short diatom bursts), with a high average biomass of 160 mg C m⁻³. The dominance of small-sized phytoplankton cells (notably green algae), low nutrient concentrations (e.g. 0.3 μM NO₃⁻ on average) and high biomass of heterotrophic protists (mostly naked ciliates and tintinnids) all point to the importance of the microbial food web in this shallow marine environment. Sustained cultivation of suspended mussels in the lagoon suggests that these heterotrophic protists could be an important source of food for the mussels, supplementing the small amount of phytoplankton present.