Could Greek and Italic share a same Indo-European substratum?

International audienceGreek and Latin have developed from their common Proto-Indo-European (PIE) ancestor in distinct ways, resulting in two languages that exhibit very different features, in particular regarding phonology and Wortbildung. Moreover, the Greek lexicon has long been recognised for its huge proportion of non-inherited words, among which it is difficult to draw a clear distinction between substrata and loan words. Several of the languages that contributed to shaping the Greek lexicon are Indo-European. Among the Indo-European contributors to the non-inherited Greek lexicon, we tentatively identify a language that shares phonetic and morphological features with substratic elements attested in Italic, and possibly articulatory properties of Latin itself. We shall review five phonetic features of this language: (i) voiceless reflexes of PIE voiced aspirated stops; (ii) the anticipation of nasals resembling lex-unda in Latin but generalised to labial stops, such that VCnV > VnGV with lenition of the consonant; (iii) a velarised /ł/ (viz. l pinguis) which can trigger an anaptyctic -ŏ- or -ŭ-; (iv) apparent voice alternations that follow similar patterns to the Verner law in Germanic; (v) the metathesis of -r-, such that CVrC > CrVC. Our study also unveils morphological peculiarities of this language: (a) the frequent use of elsewhere poorly attested labial morphs, leading to nouns of the form *CóC-Po- and adjectives of the form *CoC-Pó-; (b) the frequent use of a prefix *eǵhs- (cf. Lat. ex-, Gr. ἐξ-) reflected as a simple *s-; (c) the frequent occurrence of action nouns built with the well-known *CóC-no- pattern

Hippocampal replays under the scrutiny of reinforcement learning models

International audienceMultiple in vivo studies have shown that place cells from the hippocampus replay previously experienced trajectories. These replays are commonly considered to mainly reflect memory consolidation processes. Some data, however , have highlighted a functional link between replays and reinforcement learning (RL). This theory, extensively used in machine learning, has introduced efficient algorithms and can explain various behavioral and physiological measures from different brain regions. RL algorithms could constitute a mechanistic description of replays, and explain how replays can reduce the number of iterations required to explore the environment during learning. We review here the main findings concerning the different hippocampal replay types and the possible associated RL models (either model-based, model-free or hybrid model types). We conclude by tying these frameworks together. We illustrate the link between data and RL through a series of model simulations. This review, at the frontier between informatics and biology, paves the way for future work on replays

Radiative, magnetic and numerical feedbacks on small-scale fragmentation

Radiative feedback and magnetic field are understood to have a strong impact on the protostellar collapse. We present high resolution numerical calculations of the collapse of a 1 M⊙ dense core in solid body rotation, including both radiative transfer and magnetic field. Using typical parameters for low-mass cores, we study thoroughly the effect of radiative transfer and magnetic field on the first core formation and fragmentation. We show that including the two aforementioned physical processes does not correspond to the simple picture of adding them separately. The interplay between the two is extremely strong, via the magnetic braking and the radiation from the accretion shoc

RetrOryza: a database of the rice LTR-retrotransposons

Long terminal repeat (LTR)-retrotransposons comprise a significant portion of the rice genome. Their complete characterization is thus necessary if the sequenced genome is to be annotated correctly. In addition, because LTR-retrotransposons can influence the expression of neighboring genes, the complete identification of these elements in the rice genome is essential in order to study their putative functional interactions with the plant genes. The aims of the database are to (i) Assemble a comprehensive dataset of LTR-retrotransposons that includes not only abundant elements, but also low copy number elements. (ii) Provide an interface to efficiently access the resources stored in the database. This interface should also allow the community to annotate these elements. (iii) Provide a means for identifying LTR-retrotransposons inserted near genes. Here we present the results, where 242 complete LTR-retrotransposons have been structurally and functionally annotated. A web interface to the database has been made available (), through which the user can annotate a sequence or search for LTR-retrotransposons in the neighborhood of a gene of interest

Engineering the Floquet spectrum of superconducting multiterminal quantum dots

Here we present a theoretical investigation of the Floquet spectrum in multiterminal quantum dot Josephson junctions biased with commensurate voltages. We first draw an analogy between the electronic band theory and superconductivity which enlightens the time-periodic dynamics of the Andreev bound states. We then show that the equivalent of the Wannier-Stark ladders observed in semiconducting superlattices via photocurrent measurements, appears as specific peaks in the finite frequency current fluctuations of superconducting multiterminal quantum dots. In order to probe the Floquet-Wannier-Stark ladder spectra, we have developed an analytical model relying on the sharpness of the resonances. The charge-charge correlation function is obtained as a factorized form of the Floquet wave-function on the dot and the superconducting reservoir populations. We confirm these findings by Keldysh Green's function calculations, in particular regarding the voltage and frequency dependence of the resonance peaks in the current-current correlations. Our results open up a road-map to quantum correlations and coherence in the Floquet dynamics of superconducting devices.Comment: 13 pages, 7 figures, Supplemental Material as ancillary file (7 pages), revised manuscript, Physical Review Editors' suggestio

A valence bond view of isocyanides' electronic structure

International audienceHigh level Valence Bond calculations support a predominantly carbenic electronic structure for isocyanides, with a secondary zwitterionic character, despite their linear geometry. This geometry results from the significant energetic stabilization due to nitrogen π lone pair donation. Results are not changed by substitution or solvation effects

Role of vitamin D in HIV infection

La vitamine D possède des propriétés sur le métabolisme phosphocalcique mais aussi dans diverses pathologies telles que les maladies auto-immunes, les cancers, les maladies cardio-vasculaires, l’excès de poids ou encore certaines infections. Nous nous intéressons ici aux relations frappantes qui existent entre la vitamine D et le VIH. Cette hormone joue assurément un rôle important dans l’infection par le VIH, tant au niveau squelettique qu’au niveau de l’évolution de la maladie elle-même. Nous remarquons en effet qu’un déficit en vitamine D est très souvent associé à l’infection par le VIH. De plus, un taux indétectable de cette hormone chez les patients séropositifs est associé à une infection cliniquement plus avancée et à une mortalité accrue. Ainsi, le déficit en vitamine D doit être considéré comme un cofacteur important de la progression de l’infection par le VIH. En effet, la vitamine D augmente l’activité des macrophages, entre autres via le processus d’autophagie, ce qui permet d’inhiber l’infection par le VIH-1. Nous parlerons ensuite de l’impact de certains traitements antirétroviraux sur l’altération du métabolisme de la vitamine D. Nous évaluerons enfin le bénéfice d’une supplémentation en vitamine D chez ces patients.Peer reviewe

PROPHYLACTIC EVALUATION OF SHOULDER PROPRIOCEPTION IN ELITE SWIMMERS

It is suggested that poor shoulder proprioception contributes to shoulder pain in swimmers. However, there is a lack of studies describing the measurement method for shoulder proprioception. The purposes of this preliminary study was to investigate the scapular position depending on arm scaption as a first step in the development of a measurement method for three-dimensional shoulder proprioception. An asymptomatic young adults participated in this study. His scapular rotation were measured as a function of arm position during scaption in two consecutive days. The results showed that scapular rotations are not a reproducible function of humerus elevation. Those findings suggested that the assessement of shoulder proprioception should rely on the evaluation of both gleno-humeral and scapulo-thoracic joints to be valid