• Neuroinformatics
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AbstractBOLD fMRI is widely applied in human neuroscience but is limited in its spatial specificity due to a cortical‐depth‐dependent venous bias. This reduces its localization specificity with respect to neuronal responses, a disadvantage for neuroscientific research. Here, we modified a submillimeter BOLD protocol to selectively reduce venous and tissue signal and increase cerebral blood volume weighting through a pulsed saturation scheme (dubbed Arterial Blood Contrast) at 7 T. Adding Arterial Blood Contrast on top of the existing BOLD contrast modulated the intracortical contrast. Isolating the Arterial Blood Contrast showed a response free of pial‐surface bias. The results suggest that Arterial Blood Contrast can modulate the typical fMRI spatial specificity, with important applications in in‐vivo neuroscience.

International audience; Defining formalisms and models in modular way is a painful task. Metamodeling tools and languages have usually not been created with this goal in mind. This article proposes a data structure, called layered data, that allows defining easily modular abstract syntax for formalisms and models. It also shows its use through an exhaustive example. As a side effect, this article discusses the notion of formalism, and as- serts that they do not exist as standalone objects, but rather as relations between models.

International audience

While the virtuous relationship between transport infrastructures and development remains one the most believed myths, empirical studies looking at the effects of high-speed rail services show mitigated results. Thisicle takes advantage of the French experience to assess the economic benefits brought to the cities served by High Speed Trains (HST), partly or completely placed on a High Speed Line (HSL). The sample includes 492 urban units (UU) for which the evolution of employment, notably of executives, is studied over 1982-2006. As the choice of the territories served by HSL/HST is not random, we use a selection model. Empirical assessments of railway services cannot neglect endogeneity issues between infrastructures and local development. The selection model shows results with an opposite sign to the ones based on the Ordinary Least Squares method. Our estimates particularly emphasize the differences between UUs served by HSL or simply by HST. The UUs served on HSL have faced a lower rate of jobs (executives) creation but the effects of infrastructures on the annual growth rate are about +1.3% (+3.7%) once corrected from the selection bias. The UUs served by HST partly placed on classical railway have experienced better average performances but the effect directly due to infrastructures is negative: respectively -1.1 % and -3.0 %. These results could be useful to complete the traditional socio-economical assessments of infrastructure projects. Urban externalities, Economic Base theory, selection model, treatment effect

International audience

International audience; In this article we present the Littlewood-Paley theory and illustrate the effectiveness of this microlocal analysis tool in the study of partial differential equations, in a context which is the least technical possible. As we shall see below, the Littlewood-Paley theory provides a robust approach not only to the separate study of the various regimes of solutions to nonlinear partial differential equations, but also to the fine study of functional inequalities, and to make them accurate. 1. The Littlewood-Paley theory : a tool that has become indispensable The Littlewood-Paley theory is a localization procedure in the frequency space that, since about three decades ago, has established itself as a very powerful tool in harmonic analysis. The first goal of this text is to present it in a way as simple as possible 1. Its basic idea is contained in two fundamental inequalities known as Bernstein's inequalities, that describe some properties of functions whose Fourier transform have compact support. The first inequality says that, for a tempered distribution 2 in R d whose Fourier transform is supported in a annulus of size λ, to differentiate first and then take the L p norm is the same as to apply a homothety of ratio λ on the L p norm. In the L 2 setting this remarkable property is an easy consequence of the action of the Fourier transform on derivatives and of the Fourier-Plancherel formula. The proof in the case of general L p spaces uses Young's inequalities and the fact that the Fourier transform of a convolution is the product of the Fourier transforms. In the other hand, the second inequality tells us that, for such a distribution, the change from the L p norm to the L q norm, with q ≥ p ≥ 1, costs λ d 1 p − 1 q , which must be understood as a Sobolev embedding. It is proved like the first inequality, using Young's inequalities and the relation between the Fourier transform and the convolution product. Fourier Analysis is at the heart of the Littlewood-Paley theory, which has inspired a large number of my works. It was in conducting experiments on the propagation of heat that Joseph Fourier at the end of the 18th century opened the door to that theory, which was hugely expanded on the 20th century and intervenes in the majority of branches of Physics. In this theory having the name of its creator, one performs the frequency analyis of a function f of L 1 (R d) by the formula : f (ξ) = R d e −ix·ξ f (x) dx .

Microsatellites and minisatellites are two classes of tandem repeat sequences differing in their size, mutation processes, and chromosomal distribution. The boundary between the two classes is not defined. We have developed a convenient, hybridization-based human library screening procedure able to detect long CA-rich sequences. Analysis of cosmid clones derived from a chromosome 1 library show that cross-hybridizing sequences tested are imperfect CA-rich sequences, some of them showing a minisatellite organization. All but one of the 13 positive chromosome 1 clones studied are localized in chromosomal bands to which minisatellites have previously been assigned, such as the 1pter cluster. To test the applicability of the procedure to minisatellite detection on a larger scale, we then used a large-insert whole-genome PAC library. Altogether, 22 new minisatellites have been identified in positive PAC and cosmid clones and 20 of them are telomeric. Among the 42 positive PAC clones localized within the human genome by FISH and/or linkage analysis, 25 (60%) are assigned to a terminal band of the karyotype, 4 (9%) are juxtacentromeric, and 13 (31%) are interstitial. The localization of at least two of the interstitial PAC clones corresponds to previously characterized minisatellite-containing regions and/or ancestrally telomeric bands, in agreement with this minisatellite-like distribution. The data obtained are in close agreement with the parallel investigation of human genome sequence data and suggest that long human (CA)s are imperfect CA repeats belonging to the minisatellite class of sequences. This approach provides a new tool to efficiently target genomic clones originating from subtelomeric domains, from which minisatellite sequences can readily be obtained.[The sequence data described in this paper have been submitted to the EMBL data library under accession nos.AJ000377–AJ000383.]

The brain-derived neurotrophic factor (BDNF) is involved not only in promoting neuronal outgrowth and differentiation, synaptic connectivity and neuronal repair, but also in modulating eating behavior. Since genetic factors likely contribute to the biological vulnerability to bulimia nervosa (BN) and binge eating disorder (BED), we investigated whether the functional 196G/A single nucleotide polymorphism (SNP) of the BDNF gene was associated to BN and/or BED or to some phenotypic aspects of the disordered eating. Two hundred and ten Caucasian women (126 with BN, 84 with BED and 121 healthy controls) participated into the study. No significant differences were found in the frequencies of the 196G/A variants of the BDNF gene among patients with BN or BED and healthy controls. In both BN and BED groups, subjects carrying the 196A/A genotype exhibited a weekly frequency of bingeing and a severity of binge eating (as assessed by the Bulimia Investigation Test Edinburgh) significantly higher than those with the 196A/G and 196G/G genotypes. These results suggest that the 196G/A SNP of the human BDNF gene does not contribute to the genetic susceptibility to BN and BED, but may predispose those patients to a more severe binge eating behavior.

Preoperative clinical magnetic resonance imaging (MRI) protocols for gliomas, brain tumors with dismal outcomes due to their infiltrative properties, still rely on conventional structural MRI, which does not deliver information on tumor genotype and is limited in the delineation of diffuse gliomas. The GliMR COST action wants to raise awareness about the state of the art of advanced MRI techniques in gliomas and their possible clinical translation or lack thereof. This review describes current methods, limits, and applications of advanced MRI for the preoperative assessment of glioma, summarizing the level of clinical validation of different techniques. In this first part, we discuss dynamic susceptibility contrast and dynamic contrast‐enhanced MRI, arterial spin labeling, diffusion‐weighted MRI, vessel imaging, and magnetic resonance fingerprinting. The second part of this review addresses magnetic resonance spectroscopy, chemical exchange saturation transfer, susceptibility‐weighted imaging, MRI‐PET, MR elastography, and MR‐based radiomics applications.Evidence Level: 3Technical Efficacy: Stage 2