Assessment of actinobacteria use in the elimination of multidrug-resistant bacteria of Ibn Tofail hospital wastewater (Marrakesh,Morocco): a chemometric data analysis approach

Environmental Science and Pollution Research - The efficiency of the treatment of hospital wastewater by actinobacteria was investigated using two chemometric data analysis methods. Six strains of...     

An in vitro bioassay to assess the potential global toxicity of waters on spermatogenesis: a pilot study

Environmental Science and Pollution Research - Many toxicants are present in water as a mixture. Male infertility is one of the environmental impacts in developed countries. Using our rat...     

Prenatal overgrowth and mosaic trisomy 15q25-qter including the IGF1 receptor gene

Overgrowth is rarely associated with chromosomal imbalances. Here, we report on a male foetus presenting with overgrowth and additional material on the short arm of one of the chromosome 15 in 12% of lymphocytes and 50% of amniotic cells. Parents' karyotypes were normal, indicating a de novo origin for this unbalanced rearrangement. Complementary studies using cytogenetic and FISH studies showed that this additional material resulted in a 15q25-qter trisomy and confirmed the presence of three copies of the insulin-like growth factor 1 receptor (IGF1R) gene, included in the trisomic region. Autopsy performed after termination of pregnancy revealed isolated overgrowth and absence of visceral malformations. The possible mechanisms and origins for the formation of this mosaic pure trisomy are complex. The present observation emphasises the hypothesis that the overgrowth phenotype, frequently reported in patients with trisomy including the 15q26 region, might be causally related to a dosage effect of the IGF1R gene, as well as the importance of chromosome analysis in patients with overgrowth. It also confirms that the overgrowth is of prenatal onset in those observations. Copyright © 2004 John Wiley & Sons, Ltd.     

Evaluation of the Effect of Chemical or Enzymatic Synthesis Methods on Biodegradability of Polyesters

This work compares the biodegradability of polyesters produced by an esterification reaction between glycerol and oleic di-acid (D 18:1) issued from green chemical pathways, via either classical thermo-chemical methods, or an enzymatic method using the immobilized lipase of Candida antartica B (Novozym 435). An elastomeric polymer synthesized by enzymatic catalysis is more biodegradable than an elastomeric thermo-chemical polyester synthesized by a standard chemical procedure. This difference lies in percentage of the dendritic motifs, in values of the degree of substitution, and certainly in cross-links inducing an hyper-branched structure less accessible to the lipolytic enzymes in a waste treatment plant. However, when the elastomeric polymer synthesized by enzymatic catalysis is processed at high temperature as required for certain industrial applications, it presents an identical rate of biodegradation than the chemical polyester. The advantages of the thermo-chemical methods are greater speed and lower cost. Enzymatic synthesis appears be suited to producing polyesters, devoid of metallic catalysts, which must be used without processing at high temperature to keep a high biodegradability.     

MSWI bottom ash used as basement at two pilot-scale roads: Comparison of leachate chemistry and reactive transport modeling

The recycling of municipal solid waste incineration bottom ash as aggregates for road basement requires assessing the long-term evolution of leachate chemistry. The Dåva (Sweden) and Hérouville (France) pilot-scale roads were monitored during 6 and 10 years, respectively. Calculated saturation indices were combined to batch test modeling to set a simplified geochemical model of the bottom ash materials. A common reactive transport model was then applied to both sites. At Hérouville, pH and the concentration of most elements quickly drop during the first two years to reach a set of minimum values over 10 years. The decrease is less pronounced at Dåva. The evolutions of pH and major element concentrations are fairly well related to the following pH-buffering sequence: portlandite, C-S-H phases or pseudo-wollastonite and, finally, calcite in equilibrium with atmospheric CO₂. Al(OH)₃, barite, ettringite and monohydrocalcite may also control leachate chemistry. Cu release is correctly modeled by DOM complexation and tenorite equilibrium. Temperature has no significant effect on the modeling of leachate chemistry in the range 5-30 °C, except at high pH. Effects at road edges and roadside slopes are important for the release of the less reactive elements and, possibly, for carbonation processes.     

Architecture of 54 moist-forest tree species: traits, trade-offs, and functional groups

Tree architecture is an important determinant of the height extension, light capture, and mechanical stability of trees, and it allows species to exploit the vertical height gradient in the forest canopy and horizontal light gradients at the forest floor. Tropical tree species partition these gradients through variation in adult stature (Hmax) and light demand. In this study we compare 22 architectural traits for 54 Bolivian moist-forest tree species. We evaluate how architectural traits related to Hmax vary with tree size, and we present a conceptual scheme in which we combine the two axes into four different functional groups. Interspecific correlations between architecture and Hmax varied strongly from negative to positive, depending on the reference sizes used. Stem height was positively related to Hmax at larger reference diameters (14-80 cm). Species height vs. diameter curves often flattened toward their upper ends in association with reproductive maturity for species of all sizes. Thus, adult understory trees were typically shorter than similar-diameter juveniles of larger species. Crown area was negatively correlated with Hmax at small reference heights and positively correlated at larger reference heights (15-34 m). Wide crowns allow the small understory species to intercept light over a large area at the expense of a reduced height growth. Crown length was negatively correlated with Hmax at intermediate reference heights (4-14 m). A long crown enables small understory species to maximize light interception in a light-limited environment. Light-demanding species were characterized by orthotropic stems and branches, large leaves, and a monolayer leaf arrangement. They realized an efficient height growth through the formation of narrow and shallow crowns. Light demand turned out to be a much stronger predictor of tree architecture than Hmax, probably because of the relatively low, open, and semi-evergreen canopy at the research site. The existence of four functional groups (shade-tolerant, partial-shade-tolerant, and long- and short-lived pioneer) was confirmed by the principal component and discriminant analysis. Both light demand and Hmax capture the major variation in functional traits found among tropical rain forest tree species, and the two-way classification scheme provides a straightforward model to understand niche differentiation in tropical forests.     

Reproductive isolation between Pogonomyrmex rugosus and two lineages with genetic caste determination

Hybrid speciation occurs when combination of two interspecific genomes results in individuals that are of high fitness but reproductively incompatible with the parental species. Although hybrid speciation is a relatively common source of new species in plants, it appears to be a much rarer occurrence in animal taxa. Here we report on reproductive isolation and range overlap between the rough harvester ant Pogonomyrmex rugosus and two lineages with hybrid genotypes (H 1 and H2). Both lineages obligately interbreed and produce genetically distinct queen and worker offspring, a phenomenon referred to as genetic caste determination (GCD). Diploid offspring produced by gametes of the same lineage develop only into queens, whereas diploid offspring derived from gametes of distinct lineages develop into workers. We investigated small-scale patterns of gene flow between the parent and the two H lineages by sampling along an 80-km transect between a pure P. rugosus population and a two-lineage population. Microsatellite and mitochondrial markers both indicated virtually no gene flow between the parent species and either lineage even at sites where parental and H-lineage colonies co-occurred. The geographic ranges of the parental species and the two-lineage population were essentially parapatric, with a surprisingly narrow band of overlap and evidence of spatial structuring even at microgeographic scales within the transition zone. This suggests that ecological competition with the parent species plays a significant role in determining the evolutionary persistence and current distribution of the hybrid lineages and the genetic caste system.     

Sonographic findings in Beckwith–Wiedemann syndrome related to H19 hypermethylation

Beckwith–Wiedemann syndrome (BWS) is an overgrowth syndrome associated with congenital malformations and tumour predisposition. BWS results from variable mutations or epigenetic modifications of imprinted genes in the 11p15 chromosomal region. We present a fetus with mild general overgrowth and bilateral enlarged echogenic kidneys with loss of the corticomedullary differentiation in which prenatal diagnosis of BWS was suspected. The rest of the fetal anatomy and the amniotic fluid volume appeared normal. After termination of the pregnancy, molecular analysis confirmed the diagnosis of BWS by showing an isolated hypermethylation of the H19 gene. Copyright © 2004 John Wiley & Sons, Ltd.     

Assessing the Impact of Carbon Tax Differentiation in the European Union

To what extent do the welfare costs associated with the implementation of the Burden Sharing Agreement in the European Union depend on sectoral allocation of emissions rights? What are the prospects for strategic climate policy to favor domestic production? This paper attempts to answer those questions using a CGE model featuring a detailed representation of the European economies. First, numerical simulations show that equalizing marginal abatement costs across domestic sectors greatly reduces the burden of the emissions constraint but also that other allocations may be preferable for some countries because of pre-existing tax distortions. Second, we show that the effect of a single country's attempt to undertake a strategic policy to limit impacts on its domestic energy-intensive industries has mixed effects. Exempting energy-intensive industries from the reduction program is a costly solution to maintain the international competitiveness of these industries; a tax-cum-subsidy approach is shown to be better than exemption policy to sustain exports. The welfare impact either policy – exemption or subsidy – on other European countries is likely to be small because of general equilibrium effects.