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The C-Terminal Domain from S. cerevisiae Pat1 Displays Two Conserved Regions Involved in Decapping Factor Recruitment
No full textInternational audienceEukaryotic mRNA decay is a highly regulated process allowing cells to rapidly modulate protein production in response to internal and environmental cues. Mature translatable eukaryotic mRNAs are protected from fast and uncontrolled degradation in the cytoplasm by two cis-acting stability determinants: a methylguanosine (m7G) cap and a poly(A) tail at their 5′ and 3′ extremities, respectively. The hydrolysis of the m7G cap structure, known as decapping, is performed by the complex composed of the Dcp2 catalytic subunit and its partner Dcp1. The Dcp1-Dcp2 decapping complex has a low intrinsic activity and requires accessory factors to be fully active. Among these factors, Pat1 is considered to be a central scaffolding protein involved in Dcp2 activation but also in inhibition of translation initiation. Here, we present the structural and functional study of the C-terminal domain from S. cerevisiae Pat1 protein. We have identified two conserved and functionally important regions located at both extremities of the domain. The first region is involved in binding to Lsm1-7 complex. The second patch is specific for fungal proteins and is responsible for Pat1 interaction with Edc3. These observations support the plasticity of the protein interaction network involved in mRNA decay and show that evolution has extended the C-terminal alpha-helical domain from fungal Pat1 proteins to generate a new binding platform for protein partners
Highly Efficient Synthesis of the Tricyclic Core of Taxol by Cascade Metathesis
No full textInternational audienceAn efficient enantioselective synthesis of the ABC tricyclic core of the anticancer drug Taxol is reported. The key step of this synthesis is a cascade metathesis reaction, which leads in one operation to the required tricycle if appropriate fine-tuning of the dienyne precursor is performed
A free boundary problem for the localization of eigenfunctions
No full text174 pagesWe study a variant of the Alt, Caffarelli, and Friedman free boundary problem with many phases and a slightly different volume term, which we originally designed to guess the localization of eigenfunctions of a Schrödinger operator in a domain. We prove Lipschitz bounds for the functions and some nondegeneracy and regularity properties for the domains
Probing ultrashort-pulse laser excitation of sapphire: From the initial carrier creation to material ablation
No full textInternational audienceUltrashort-pulse laser excitation of dielectrics has been investigated over a large span of intensities. Experimentally, single-shot studies on single-crystal sapphire samples combine time-resolved spectral interferometry with time-resolved reflectivity and ablation-rate measurements. The complete development of the excitation from the first creation of conduction-band electrons at low intensities to the formation of a highly excited plasma and associated material fragmentation is observed experimentally and explained by a single theoretical model, which combines material excitation in a multiple-rate equation description with light propagation. Copyright (C) EPLA, 201
Vers une caracterisation polarimétrique de Mueller endocopique pour l'aide au diagnostic médical
No full textDimensions of spaces of level one automorphic forms for split classical groups using the trace formula
No full text89 pages, 28 tables, comments welcome. Much more data available at http://www.math.ens.fr/~taibi/dimtrace/We consider the problem of explicitly computing dimensions of spaces of automorphic or modular forms in level one, for a split classical group over such that has discrete series. Our main contribution is an algorithm calculating orbital integrals for the characteristic function of at torsion elements of . We apply it to compute the geometric side in Arthur's specialisation of his invariant trace formula involving stable discrete series pseudo-coefficients for . Therefore we explicitly compute the Euler-Poincaré characteristic of the level one discrete automorphic spectrum of with respect to a finite-dimensional representation of . For such a group , Arthur's endoscopic classification of the discrete spectrum allows to analyse precisely this Euler-Poincaré characteristic. For example one can deduce the number of everywhere unramified automorphic representations of such that is isomorphic to a given discrete series representation of . Dimension formulae for the spaces of vector-valued Siegel modular forms are easily derived
Compositionality Results for Quantitative Information Flow
No full textInternational audienceIn the min-entropy approach to quantitative information flow, the leakage is defined in terms of a minimization problem, which, in case of large systems, can be computationally rather heavy. The same happens for the recently proposed generalization called g-vulnerability. In this paper we study the case in which the channel associated to the system can be decomposed into simpler channels, which typically happens when the observables consist of several components. Our main contribution is the derivation of bounds on the g-leakage of the whole system in terms of the g-leakage of its components
Native language, spoken language, translation and trade
No full textInternational audienceWe construct new series for common native language and common spoken language for 195 countries, which we use together with series for common official language and linguistic proximity in order to draw inferences about (1) the aggregate impact of all linguistic factors on bilateral trade, (2) the separate role of ease of communication as distinct from ethnicity and trust, and (3) the contribution of translation and interpreters to ease of communication. The results show that the impact of linguistic factors, all together, is at least twice as great as the usual dummy variable for common language, resting on official language, would say. In addition, ease of communication plays a distinct role, apart from ethnicity and trust, and so far as ease of communication enters, translation and interpreters are significant. Finally, emigrants have much to do with the role of ethnicity and trust in linguistic influence
Denominator vectors and compatibility degrees in cluster algebras of finite type
No full textInternational audienceWe present two simple descriptions of the denominator vectors of the cluster variables of a cluster algebra of finite type, with respect to any initial cluster seed: one in terms of the compatibility degrees between almost positive roots defined by S. Fomin and A. Zelevinsky, and the other in terms of the root function of a certain subword complex. These descriptions only rely on linear algebra. They provide two simple proofs of the known fact that the -vector of any non-initial cluster variable with respect to any initial cluster seed has non-negative entries and is different from zero
Familial occurrence and heritable connective tissue disorders in cervical artery dissection.
No full textErratum in: Familial occurrence and heritable connective tissue disorders in cervical artery dissection. [Neurology. 2016]International audienceIn a large series of patients with cervical artery dissection (CeAD), a major cause of ischemic stroke in young and middle-aged adults, we aimed to examine frequencies and correlates of family history of CeAD and of inherited connective tissue disorders. We combined data from 2 large international multicenter cohorts of consecutive patients with CeAD in 23 neurologic departments participating in the CADISP-plus consortium, following a standardized protocol. Frequency of reported family history of CeAD and of inherited connective tissue disorders was assessed. Putative risk factors, baseline features, and 3-month outcome were compared between groups. Among 1,934 consecutive patients with CeAD, 20 patients (1.0%, 95% confidence interval: 0.6%-1.5%) from 17 families (0.9%, 0.5%-1.3%) had a family history of CeAD. Family history of CeAD was significantly more frequent in patients with carotid location of the dissection and elevated cholesterol levels. Two patients without a family history of CeAD had vascular Ehlers-Danlos syndrome with a mutation in COL3A1. This diagnosis was suspected in 2 additional patients, but COL3A1 sequencing was negative. Two patients were diagnosed with classic and hypermobile Ehlers-Danlos syndrome, one patient with Marfan syndrome, and one with osteogenesis imperfecta, based on clinical criteria only. In this largest series of patients with CeAD to date, family history of symptomatic CeAD was rare and inherited connective tissue disorders seemed exceptional. This finding supports the notion that CeAD is a multifactorial disease in the vast majority of cases