Science & Mathematics

It is shown that asymptotically consistent modifications of (Boussinesq-like) shallow water approximations, in order to improve their dispersive properties, can fail for uneven bottoms (i.e., the dispersion is actually not improved). It is also shown that these modifications can lead to ill-posed equations when the water depth is not constant. These drawbacks are illustrated with the (fully nonlinear, weakly dispersive) Serre equations. We also derive asymptotically consistent, well-posed, modified Serre equations with improved dispersive properties for constant slopes of the bottom.

We give a general presentation of euclidean buildings. This includes vectorial buildings (a variety of Tits buildings) and affine buildings (e.g. Bruhat-Tits buildings. For the general definition the emphasis is given to facets (even in the non-discrete case). More details are given for the buildings of the reductive group GL(n).

In this study, a new degradation path of sunscreen active ingredient, 2-ethylhexyl-4-methoxycinnamate (EHMC) and 4-methoxycinnamic acid (MCA) in the presence of sodium hypochlorite (NaOCl), was discussed. The reaction products were detected using gas chromatography–mass spectrometry (GC-MS). Since HOCl treatment leads to more polar products than EHMC, application of polar extracting agents, dichloromethane and ethyl acetate/n-hexane mixture, gave better results in terms of chlorinated breakdown products identification than n-hexane. Reaction of EHMC with HOCl lead to the formation of C=C bridge cleavage products such as 2-ethylhexyl chloroacetate, 1-chloro-4-methoxybenzene, 1,3-dichloro-2-methoxybenzene, and 3-chloro-4-methoxybenzaldehyde. High reactivity of C=C bond attached to benzene ring is also characteristic for MCA, since it can be converted in the presence of HOCl to 2,4-dichlorophenole, 2,6-dichloro-1,4-benzoquinone, 1,3-dichloro-2-methoxybenzene, 1,2,4-trichloro-3-methoxybenzene, 2,4,6-trichlorophenole, and 3,5-dichloro-2-hydroxyacetophenone. Surprisingly, in case of EHMC/HOCl/UV, much less breakdown products were formed compared to non-UV radiation treatment. In order to describe the nature of EHMC and MCA degradation, local reactivity analysis based on the density functional theory (DFT) was performed. Fukui function values showed that electrophilic attack of HOCl to the C=C bridge in EHMC and MCA is highly favorable (even more preferable than phenyl ring chlorination). This suggests that HOCl electrophilic addition is probably the initial step of EHMC degradation.

Cet article examine les conditions d'emprunt pour une collectivité désirant acquérir un bien immobilier ; on dérive une règle simple applicable à des paramètres observables.

Légende manuscrite sur le document original : "France : Pays Méditerranéens : Languedoc Méditerranéen : La Gardiole, la plateforme inférieure (40 m) sur le versant Sud-Ouest, au fond la Chapelle Sainte Bauzille 197 m". Les plaques de verre déposées à Prodig datent de 1891 à 1954. Géolocalisation : approximative centrée sur la chapelle Saint-Bauzille.

In this work the properties of PECVD-carbon films before and after Rapid Thermal Annealing (RTA) are presented. The thickness of the investigated films is in the range 50 - 6000Å. The layers are annealed at 1400°C for different times of 1 s to 3 min in vacuum 5 x 10-5 Torr. Raman investigation has been performed before and after annealing.

Les Laboratoires de l’Urodonal, dès 1916, et sous l’impulsion d’Alexandre Ehrmann, se lancent dans la publicité suggestive pour vanter les mérites de leurs remèdes-miracles. Les motifs du voyage intérieur et de l’homme miniaturisé deviennent alors récurrents : petit ramoneur de l’intestin, lavage d’un rein à grandes eaux, trépanation par des hommes miniatures, etc.

Nicotinamide phosphoribosyltransferase (NAMPT) is the rate-limiting enzyme for the synthesis of nicotinamide adenine dinucleotide (NAD+). NAD+ is a cofactor in multiple redox reactions related to cellular energy production and is also used as a substrate by enzymes involved in regulating important functions, including energy metabolism, DNA repair, apoptosis, inflammation, and gene expression. NAMPT is a glycosyltransferase involved in the first step reaction of the so-called salvage pathway, where nicotinamide (NAM) generates NAD+. NAD+ biosynthesis is dependent on different metabolic pathways, but the salvage pathway represents the major route to NAD+ biosynthesis. Moreover, NAMPT is frequently up-regulated in cancer where it contributes to cancer cell metabolism. Overall, since many cancer cells are highly dependent on NAMPT activity for proliferation, NAMPT represents an attractive target in cancer research. Over the last years, several compounds were identified as potent NAMPT inhibitors with strong anti-cancer activity. The NAMPT inhibitors (FK866 and CHS828), discovered in the early 2000s, have exhibited anticancer activity by depleting NAD+ and ATP levels and have reached phase II and phase I clinical trials, respectively. Unfortunately, these trials were stopped due to limited antitumor activity and to toxicity problems, mainly thrombocytopenia and gastrointestinal toxicity. Over the past 20 years, many inhibitors have been designed based on a unique pharmacophore model.This PhD dissertation aims at finding out a “next generation” of NAMPT inhibitors which present a better solubility profile and a chemical design that differs from those previously proposed. We focused on the design of new inhibitors of NAMPT with the aim of mimicking the transition state formed in the rate-determining step of the glycosylation process catalysed by the enzyme. As a new potential inhibitor of NAMPT we designed and synthesised C-iminofuranosides linked through the anomeric carbon to a moiety closely related to FK866. The iminofuranoside should mimic the ribosyl moiety, the natural substrate for the enzyme. Moreover, the conjugation with a highly hydrophilic structure as an iminosugar, could improve the solubility and pharmacokinetics properties of these potential inhibitors. We prepared 10 novel aryl β-D-iminoribitol derivatives using an enantioselective and diastereoselective L-proline catalysed method. To compare whether the iminosugar provided an advantage in inhibiting NAMPT, the corresponding molecules without the iminosugar attached were also synthesized. In parallel, we performed the synthesis of 14 NAMPT inhibitors that follow the pharmacophore model. For all the compounds, the inhibitory activity in vitro has been assessed by conducting enzymatic tests with NAMPT and biological assays in a human pancreatic cancer cell line, MiaPaca-2.We found that 3 products featuring the iminosugar moiety have moderate inhibitory activity (micromolar range) towards both enzyme and cells. From the comparison with the corresponding molecules without the attached iminosugar, we concluded that its presence does not negatively influence the activity and, in some cases, it slightly improves it. Furthermore, one of the compounds following the pharmacophore model was identified to have strong enzymatic and cellular inhibition activity, comparable to that observed for FK866.

24x36 mm, gélatine plan-film.

Ce mémoire s'intéresse à l'étude de la Bande Dessinée en cycle 3 (CM1-CM2). Une première partie théorique définit la Bande Dessinée comme un objet culturel et littéraire puis questionne l'intégration de ce genre controversé à l'école primaire. Une seconde partie expérimentale interroge les outils et les dispositifs particuliers à l'étude de la Bande Dessinée au cycle 3.

The goal of the present study is to better understand the mechanisms involved in the processing of liaison consonants by listeners in French. Previous work (Wauquier-Gravelines 1996) showed that liaison consonants are more difficult to detect than word-initial consonants in a phoneme-detection task. We examined to what extent such differences are attributable to the consonants' phonetic properties, and we also compared the perception of liaison consonants with that of fixed word-final and word-medial consonants, as well as word-initial ones. The results suggest that liaison consonants have a specific perceptual status. Implications for both autosegmental and exemplar-based theories of liaison are discussed.