Endosulfan effects on Rana dalmatina tadpoles: Quantitative developmental and behavioural analysis

in Archives of Environmental Contamination & Toxicology (2013), 64(2), 253-262

Endosulfan is an organochlorine pesticide that was recently labeled as a persistent organic pollutant, but it is still widely employed, particularly in developing countries. The goal of this study is to ... [more ▼]

Endosulfan is an organochlorine pesticide that was recently labeled as a persistent organic pollutant, but it is still widely employed, particularly in developing countries. The goal of this study is to evaluate the acute (LC50) and chronic effects (developmental and behavioural traits) of this insecticide on Rana dalmatina tadpoles after exposure to ecologically relevant concentrations (0.005, 0.01, and 0.05 mg/L) by applying video-tracking techniques to evaluate the quantitative effect of endosulfan on amphibian behavioural patterns. The 96 h LC50 value was 0.074 mg endosulfan/L. Tadpoles chronically exposed to 0.01 and 0.05 mg endosulfan/L underwent high mortality rate, decreased larval growth, delayed development, and increased incidence of malformations, and they did not reach metamorphosis by the end of the experiment. Moreover, tadpoles exposed to these concentrations exhibited several abnormalities in swimming patterns, such as shorter distance moved, swirling, resting, and unusual use of space. The exposure to 0.005 mg endosulfan/L did not cause any significant effects on behaviour, larval growth, or development, but we observed a significant decrease in both survival and time to metamorphosis. We showed that developmental abnormalities are dose-dependent and that the pesticide effects could differ depending on the endosulfan concentration and the species tested. We also validated the hypothesis that behavioural analysis, along with the use of new analytical methods, could be a useful tool in amphibian ecotoxicological studies. [less ▲]

Theatralität in E.T.A. Hoffmanns narrativen Texten: Zum Beispiel "Das Fräulein von Scuderi"

E-print/Working paper (2013)

Les formules de répartition du fonds des communes orientent-elles la fiscalité locale ?

in Revue de Fiscalité Régionale et Locale (2013), 1

The Municipal Fund, or Fonds des communes, is a general transfer to Walloon municipalities. A 1989 reform has introduced a formula taking into account fiscal returns and it was considered that this has ... [more ▼]

The Municipal Fund, or Fonds des communes, is a general transfer to Walloon municipalities. A 1989 reform has introduced a formula taking into account fiscal returns and it was considered that this has has an inlfluence on local fiscal mix. This paper analyses the evolution of the main local taxes of Walloon municipalities and present a comparison with the situation in the other Belgian regions. [less ▲]

Improving effect of metal and oxide nanoparticles encapsulated in porous silica on fermentative biohydrogen production by Clostridium butyricum.

in Bioresource Technology (2013), 133C

This paper investigated the enhancement effect of nanometre-sized metallic (Pd, Ag and Cu) or metallic oxide (Fe(x)O(y)) nanoparticles on fermentative hydrogen production from glucose by a Clostridium ... [more ▼]

This paper investigated the enhancement effect of nanometre-sized metallic (Pd, Ag and Cu) or metallic oxide (Fe(x)O(y)) nanoparticles on fermentative hydrogen production from glucose by a Clostridium butyricum strain. These nanoparticles (NP) of about 2-3nm were encapsulated in porous silica (SiO(2)) and were added at very low concentration (10(-6)molL(-1)) in batch hydrogen production test. The cultures containing iron oxide NP produced 38% more hydrogen with a higher maximum H(2) production rate (HPR) of 58% than those without NP or with silica particles only. The iron oxide NP were used in a 2.5L sequencing-batch reactor and showed no significant effect on the yields (established at 2.2mol(hydrogen)mol(glucose)(-1)) but an improvement of the HPR (+113%, reaching a maximum HPR of 86mL(hydrogen)L(-1)h(-1)). These results suggest an improvement of the electron transfers trough some combinations between enzymatic activity and inorganic materials. [less ▲]

Design of growth-dependent biosensors based on destabilized GFP for the detection of physiological behavior of Escherichia coli in heterogeneous bioreactors

in Biotechnology Progress (2013), 29(2), 553-563

In this work we present the design and characterization of GFP-based reporter systems designed in order to describe cellular activity in ‘complex’, heterogeneous bioreactors. The reporter systems consist ... [more ▼]

In this work we present the design and characterization of GFP-based reporter systems designed in order to describe cellular activity in ‘complex’, heterogeneous bioreactors. The reporter systems consist of Escherichia coli strains carrying growth dependent promoters fused to genes expressing stable and unstable variants of GFP, respectively. The response of Escherichia coli cells to transient exposure to glucose was studied in a two-compartment scale down bioreactor (SDR) consisting of a stirred tank reactor (STR) connected to plug-flow reactor (PFR). Such a SDR system is employed to mimic the situation that often encountered in large-scale, fed-batch bioreactors. The response of E. coli coli to oxygen-poor and glucose-rich regions was simulated by continuously pumping E. coli cells from STR to the PFR. A concentrated glucose pulse (400 g/L) was consecutively added at the entrance of the PFR and samples were taken from PFR. The GFP expressions were significantly marked after 10 hours of culture in STR (control reactor) and SDR, whereas, growth rates were rather similar. Additional experiments in chemostat (D=0.14 h-1) with programmed glucose perturbation (30 g/L, frequency: 100/900 s) suggested that the activities of the promoter are linked with the substrate limitation signal. Taken together with immunoblot analysis, we suppose protein leakage is responsible for the overexpression of fis and the related promoters, such as rrnB in this case study, but additional works are required in order to confirm this relationship. Our finding are of great interest for industrial application since the GFP signal can be detected very early during the culture and is related to relevant physiological changes. This investigation is useful for a better understanding of the fast dynamic phenomena occurring in heterogeneous large-scale bioreactors. [less ▲]

La pratique formelle de Marie Étienne : du geste à la manière

in Joqueviel, Marie (Ed.) Marie Etienne - Organiser l'indicible (2013)

Groupe d'Ateliers de Recherche (GAR asbl)

in Archives : pour une reconnaissance de l'architecture. Livre blanc des archives en Fédération Wallonie-Bruxelles. (2013)

Stochastic modeling in mechanics: course material

Learning material (2013)

Ab initio calculation of spin-dependent electron-phonon coupling and transport in iron and cobalt

in Journal of Physics : Condensed Matter (2013), 25

The spin-dependent coupling between electrons and phonons in ferromagnetic Fe and Co is calculated from first principles in a collinear-spin formalism. The added spin polarization is fundamental for the ... [more ▼]

The spin-dependent coupling between electrons and phonons in ferromagnetic Fe and Co is calculated from first principles in a collinear-spin formalism. The added spin polarization is fundamental for the correct representation of the phonons, but also to obtain good transport properties, and permits the decomposition (e.g. of the resistivity) into the contributions of majority and minority spin. In Fe the minority spin coupling is only about 50\% more important, but in Co the coupling between phonons and minority spin electrons is an order of magnitude larger than majority, and both are strongly anisotropic. [less ▲]

Changes in naming and semantic abilities with aging from 50 to 90 years

in Journal of the International Neuropsychological Society (2013)

The aim of this study was to determine whether naming difficulties arise in individuals as young as their 50s. Participants of 25-35, 50-59, 60-69 and above 70 years of age were given a picture naming ... [more ▼]

The aim of this study was to determine whether naming difficulties arise in individuals as young as their 50s. Participants of 25-35, 50-59, 60-69 and above 70 years of age were given a picture naming task. To uncover subtle naming difficulties, latencies were analyzed in addition to accuracy. In order to control whether the expected slower naming latencies could be due to a general slowing affecting all cognitive tasks, participants were also given an odd/even judgment task to assess cognitive processing speed. The results confirmed that participants in their 50s presented decline in naming performance, reflected by an increase in naming latencies, whereas adults in their 60s and their 70s showed both a decrease in accuracy and an increase in latency. Moreover, the increase in naming latencies remained significant even after controlling for odd/even judgment latencies, suggesting a degradation specific to the picture naming task. We assumed that these slower latencies may result from a language-specific impairment. As a further test for language-specific degradation, participants’ semantic capacities were also assessed with a synonym judgment task and the Pyramids and Palm Trees test. The above-70 group showed semantic degradation. The contributions of multiple factors to naming difficulties in aging are discussed. [less ▲]