Biomedical subjects

S Barraud

Publications and source records attributed to S Barraud.

8 recordsLinked to original sources

PubMed2006

Comparison between two methodologies for urban drainage decision aid.

The objective of the present work is to compare two methodologies based on multicriteria analysis for the evaluation of stormwater systems. The first methodology was developed in Brazil and is based on performance-cost analysis, the second one is ELECTRE III. Both methodologies were applied to a case study. Sensitivity and robustness analyses were then carried out. These analyses demonstrate that both methodologies have equivalent results, and present low sensitivity and high robustness. These results prove that the Brazilian methodology is consistent and can be used safely in order to select a good solution or a small set of good solutions that could be compared with more detailed methods afterwards.

Brazil↗

PubMed2005

Statistical analysis of pollution in stormwater infiltration basins.

In order to characterize soil pollution in stormwater infiltration basins, four basins of the Lyon area were selected and sampled. Altogether, 66 soil samples were collected. Each sample was analyzed for pH, cationic exchange capacity, particle size distribution, total organic carbon, total nitrogen, total phosphorus, metals, total hydrocarbons and polycyclic aromatic hydrocarbons (PAHs). Data was explored in a classic way (soil profiles) and using multivariate analysis techniques. Two methods were applied: Principal Component Analysis (PCA) and Cluster Analysis (CA). Main results are presented in this paper. Pollutant concentrations decrease rapidly with depth while pH and grain size increase. Sustainable concentrations are reached at a 50-cm depth, even after 21 years of operation. Multivariate analysis shows how pollution affects each sampling depth.

Carbon↗

PubMed2005

Performance-costs evaluation for urban storm drainage.

The design process of urban stormwater systems incorporating BMPs involves more complexity unlike the design of classic drainage systems for which just the technique of pipes is likely to be used. This paper presents a simple decision aid methodology and an associated software (AvDren) concerning urban stormwater systems, devoted to the evaluation and the comparison of drainage scenarios using BMPs according to different technical, sanitary, social environmental and economical aspects. This kind of tool is particularly interesting so as to help the decision makers to select the appropriate alternative and to plan the investments especially for developing countries, with important sanitary problems and severe budget restrictions.

Cities↗

PubMed2004

Genetic diversity associated with variation in silage corn digestibility for three O-methyltransferase genes involved in lignin biosynthesis.

Polymorphisms within three candidate genes for lignin biosynthesis were investigated to identify alleles useful for the improvement of maize digestibility. The allelic diversity of two caffeoyl-CoA 3-O-methyltransferase genes, CCoAOMT2 and CCoAOMT1, as well as that of the aldehyde O-methyltransferase gene, AldOMT, was evaluated for 34 maize lines chosen for their varying degrees of cell wall digestibility. Frequency of nucleotide changes averaged one SNP every 35 bp. Ninety-one indels were identified in non-coding regions and only four in coding regions. Numerous distinct and highly diverse haplotypes were identified at each locus. Numerous sites were in linkage disequilibrium that declined rapidly within a few hundred bases. For F4, an early flint French line with high cell wall digestibility, the CCoAOMT2 first exon presented many non-synonymous polymorphisms. Notably we found an 18-bp indel, which resembled a microsatellite and was associated with cell wall digestibility variation. Additionally, the CCoAOMT2 gene co-localized with a QTL for cell wall digestibility and lignin content. Together, these results suggest that genetic diversity investigated on a broader genetic basis could contribute to the identification of favourable alleles to be used in the molecular breeding of elite maize germplasm.

Alleles↗

PubMed2002

Implementation of a monitoring system to measure impact of stormwater runoff infiltration.

Stormwater infiltration is a drainage mode, which is more and more used in urban areas in France. Given the characteristics of urban surfaces, and especially the loads of various pollutants contained in stormwater, it is important to assess the impact of stormwater infiltration systems on soil and groundwater by carrying out field experiments. The main difficulty is due to the complexity of the system observed and the need of multidisciplinary approaches. Another difficulty is that measurements are carried out in situ, in an uncontrolled environment submitted to quantitatively and qualitatively highly variable interferences. Very long term monitoring is needed to get representative results. In order to contribute to solve these problems, the OTHU project has recently been launched in Lyon (France). One of its key action concerns a long-term (10 years) experiment on an infiltration basin specifically rehabilitated for measurements and operational drainage issues. This paper presents the experimental site, the objectives of the project and the way the monitoring process has been built according to the various disciplines involved (biology, ecology, hydrology, chemistry and soil sciences) and to the will of assessing all the uncertainties in the measurement process.

Cities↗

PubMed2001

The purification performance of infiltration basins fitted with pretreatment facilities: a case study.

In the south-east of France, the evacuation of stormwater by infiltration into the ground is being developed for large aquifer systems such as the ground water in the Rhône valley and in the eastern part of Lyons. A study proposal has been presented to the water management department of the conurbation of Lyons, aimed at quantifying, within a reasonably short space of time, the effects, in terms of transport of pollutants, of the stormwater infiltration system in the underground water in eastern Lyons. To this end, a one year duration experiment was carried out on the Vénissieux infiltration basin which drains stormwater from a 380 hectares industrial catchment area. Its peculiar configuration also made it possible to acquire new knowledge on the qualitative operation of a few pretreatment facilities. After describing the operation of the basin and the experimental protocol, we shall present a body of data that we monitored and our conclusions about the behaviour of the pollution throughout the facilities. Then, we present methods used to assess the pollution removal performance of the infiltration basin and its pretreatment devices, the results obtained, and our conclusions about the impact of the infiltration basin on groundwater and soil.

Cities↗

PubMed1998

Inhibitors of messenger RNA and protein synthesis affect differently serotonin arylalkylamine N-acetyltransferase activity in clock-controlled and non clock-controlled fish pineal.

The pineal organ of fish contains photoreceptor cells. In some species (e.g., pike) each photoreceptor is a cellular circadian system which contains a photoreceptive unit, the clock and an output unit. In others (e.g., trout) the clock is lacking. The main rhythmic output of the pineal photoreceptor is melatonin, an internal 'zeitgeber' of the organisms. The nocturnal rise in melatonin secretion results from an increase in the activity of the arylalkylamine-N-acetyltransferase (AA-NAT) which converts serotonin to N-acetylserotonin. In the present study we investigated the effects of transcription and translation inhibitors on AA-NAT activity in pike and trout pineal organs in culture. Cycloheximide, anisomycin, and puromycin inhibited the rise in AA-NAT activity observed during the first 2, 4 or 6 h of the dark phase, in both species. Actinomycin D was active only in the pike. Six hours of treatment during the first half of the night induced inhibition of AA-NAT activity, providing that forskolin (an adenylyl cyclase stimulator) was present in the culture medium. When the treatment was run for 3, 6 or 12 h, starting at midday of a 12L/12D cycle, basal and forskolin-stimulated AA-NAT activity (measured at midnight) were dramatically reduced. Such a treatment had no effect on trout AA-NAT activity. It is concluded that: (1) the dark-induced rise in AA-NAT activity and melatonin secretion are dependent on newly synthesized protein in both pike and trout pineal; (2) AA-NAT regulation takes place at the translational and post-translational levels in both species; (3) AA-NAT regulation occurs also at the transcriptional level in the pike, but not in the trout; and (4) the cAMP-dependent activation of AA-NAT requires transcription in the pike, not in the trout. The presence of a cell population acting as a circadian clock in the pike pineal, but not in the trout pineal, can explain the difference between these two species. Thus, we suggest that the clock mechanism operates at the genetic level in these cells. Further comparative studies between clock-controlled and non-clock-controlled pineals might prove interesting to demonstrate the difference between these two regulatory pathways.

Acetylserotonin O-Methyltransferase↗

PubMed1998

Impact of viral hemorrhagic disease on a wild population of European rabbits in France.

An outbreak of rabbit viral hemorrhagic disease (RVHD) and of myxomatosis occurred in a free-living population of rabbits (Oryctolagus cuniculus) near Paris (France) in 1995. Annual mortality rates were 88% in adults and 99% in juveniles. There was no difference in mortality rates between males and females. Since most adults were protected with myxoma antibodies after May, they probably died of RVHD. Mortality lasted throughout the year despite high proportions of rabbits having developed myxomatosis and RVHD antibodies, which suggests that the combination of the two diseases and the immunosuppressive characteristics of myxoma virus could be responsible for the mortality caused by RVHD. The proportion of juveniles with RVHD antibodies increased with their weight. Seroconversion against RVHD occurred in spring and autumn.

Animals↗