55 research outputs found
Influence of surfactants on the structure of titanium oxide gels : experiments and simulations
We report here on experimental and numerical studies of the influence of
surfactants on mineral gel synthesis. The modification of the gel structure
when the ratios water-precursor and water-surfactant vary is brought to the
fore by fractal dimension measures. A property of {\em polydispersity of the
initial hydrolysis} is proposed to explain these results, and is successfuly
tested through numerical experiments of three dimensional chemically limited
aggregation.Comment: 12 pages, 4 Postscript figures, uses RevTe
Xq27 FRAXA locus is a strong candidate for dyslexia: evidence from a genome-wide scan in French families.
Dyslexia is a frequent neurodevelopmental
learning disorder. To date, nine susceptibility loci have
been identified, one of them being DYX9, located in Xq27.
We performed the first French SNP linkage study followed
by candidate gene investigation in dyslexia by studying 12
multiplex families (58 subjects) with at least two children
affected, according to categorical restrictive criteria for
phenotype definition. Significant results emerged on
Xq27.3 within DYX9. The maximum multipoint LOD
score reached 3,884 between rs12558359 and rs454992.
Within this region, seven candidate genes were investigated
for mutations in exonic sequences (CXORF1,
CXORF51, SLITRK2, FMR1, FMR2, ASFMR1, FMR1NB),
all having a role during brain development. We further
looked for 50
UTR trinucleotide repeats in FMR1 and FMR2
genes. No mutation or polymorphism co-segregating with
dyslexia was found. This finding in French families with
Dyslexia showed significant linkage on Xq27.3 enclosing
FRAXA, and consequently confirmed the DYX9 region as
a robust susceptibility locus. We reduced the previously
described interval from 6.8 (DXS1227–DXS8091) to 4 Mb
also disclosing a higher LOD score
Investigating trophic ecology and dietary niche overlap among morphs of Lake Trout in Lake Superior
Four morphs of Lake Trout (Salvelinus namaycush, Walbaum 1792) have been identified in Lake Superior: leans, siscowets, humpers, and redfins. In this comprehensive study, the trophic ecology of Lake Trout morphs were characterized using stomach content, fatty acid, and stable isotope data. Stomach content results indicated a predominately piscivorous diet for leans, siscowets, and redfins, whereas humper diets were comprised of 50% fish and 50% Mysis by mass. Humper and siscowets were most similar in their dietary fatty acid profiles, whereas redfins had the most distinct dietary fatty acid profile. Results from stable isotope analysis revealed some among-morph differences along a pelagic-profundal consumption gradient (34S), but there were no significant differences in trophic position (15N) or basal carbon sources among morphs (13C). Using the recently developed nicheROVER software package, 4-dimensional trophic niches for each morph were quantified using stable isotope ratios (δ13C, δ15N, and δ34S) and fatty acid profiles (30 dietary fatty acids, condensed to one axis). Humpers had the largest 4-dimensional niche regions of all four morphs, and redfins had the smallest. Pairwise probability of overlap among morphs in these four-dimensional niche regions was determined to be < 50% in most cases. Overall, stomach content results indicate that humpers diets were more planktivorous than the other morphs, consistent with previous research. Results of the niche overlap analysis suggests some degree of generalist feeding for all morphs. Better characterization of seasonal variation in diet using tracers that reflect more recent feeding (e.g., fatty acids, stomach contents, and/or stable isotope analyses performed on tissues that turnover more quickly than muscle) are needed to further elucidate among-morph differences and similarities in diet and trophic ecology
Evaluation of cardiovascular flow characteristics in the 129Sv mouse foetus using color-Doppler-guided spectral Doppler ultrasound
International audienc
Structure and dynamical arrest of large size fibrillar tangles of the amyloid beta-protein(1-40).
Distribution of a cytoplasmic estrogen-induced 52 K protein in human breast tumors and double immunocytostaining with the nuclear estrogen receptor on fine needle aspirates
Défauts d’aspect des pièces moulées par injection : exemple de l’influence de la surface du moule sur les “défauts de vagues”
Cette étude expérimentale porte sur la caractérisation et la propagation des défauts de vagues sur des plaques injectées en polypropylène. Nous avons mis en évidence deux sortes de bandes brillantes (très orientées et non orientées). Le front de matière des pièces incomplètes est déséquilibré alternativement d’un coté et de l’autre du moule. La périodicité correspond aux différentes bandes orientées ou non. Nous avons montré que les conditions de contact entre le moule et le polymère fondu influence fortement l’initiation ou non de ce défaut. Nous comparons nos résultats avec quelques modèles théoriques proposés dans la littérature
Ultrasonographic examination of the adrenal gland and evaluation of the hypophyseal-adrenal axis in 20 cats
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