298 research outputs found

    The Return of the Prodigy Son: Do Return Migrants make Better Leaders?

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    This paper investigates the impact of political leaders' migration experience on the quality of their leadership. We build up an original database on the personal background of 932 politicians who were at the head of the executive power in a developing country over the 1960-2004 period. We put forward a positive e ffect of the leader having studied abroad on the level of democracy in his country during his tenure. This e ffect is shown to be independent from the leader's education level, as well as from his profession. Moreover, it is mainly driven by countries with a poor initial level of democracy. These results are con rmed by various robustness tests. They propose a new channel through which migration may a ect politics in the sending countries, namely the emergence of the elites

    Alien Registration- Mercier, Marion (Augusta, Kennebec County)

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    https://digitalmaine.com/alien_docs/18997/thumbnail.jp

    Enhancing scientific dissemination in neuroscience via preprint peer-review: "Peer Community In Circuit Neuroscience"

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    The dissemination of scientific results and new technologies in biomedical science is rapidly evolving from an exclusive and fee-oriented publishing system towards more open, free and independent strategies for sharing knowledge. In this context, preprint servers such as bioRxiv answer a very real scientific need by enabling the rapid, free and easy dissemination of findings, regardless of whether these are novel, replicated, or even showcasing negative results. Currently, thousands of manuscripts are being shared via bioRxiv each month, and neuroscience is the largest and fastest growing subject category. However, commenting on bioRxiv is declining and no structured scientific validation such as peer-review is currently available. The Peer Community In (PCI) platform addresses this unmet need by facilitating the rigorous evaluation and validation of preprints, and PCI Circuit Neuroscience (PCI C Neuro) aims to develop and extend this tool for the neuroscience community. Here we discuss PCI C Neuro's mission, how it works, and why it is an essential initiative in this new era of open science

    Cénac-et-Saint-Julien – Grotte Vaufrey

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    Date de l'opération : 2009 (EX) Datation par luminescence des dépôts sédimentaires L’objectif de l’étude initiée en 2008 est d’obtenir de l’information chronologique sur la mise en place du remplissage sédimentaire de la Grotte Vaufrey. Dans ce but, et pour compléter les données radiométriques déjà obtenues par application de la méthode Uranium-Thorium à des vestiges carbonatés et par thermoluminescence sur des fragments de calcite et des silex brûlés, no..

    Long-term potentiation in neurogliaform interneurons modulates excitation-inhibition balance in the temporoammonic pathway

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    Apical dendrites of pyramidal neurons integrate information from higher-order cortex and thalamus, and gate signalling and plasticity at proximal synapses. In the hippocampus, neurogliaform cells and other interneurons located within stratum lacunosum-moleculare mediate powerful inhibition of CA1 pyramidal neuron distal dendrites. Is the recruitment of such inhibition itself subject to use-dependent plasticity, and if so, what induction rules apply? Here we show that interneurons in mouse stratum lacunosum-moleculare exhibit Hebbian NMDA receptor-dependent long-term potentiation (LTP). Such plasticity can be induced by selective optogenetic stimulation of afferents in the temporoammonic pathway from the entorhinal cortex, but not by equivalent stimulation of afferents from the thalamic nucleus reuniens. We further show that theta-burst patterns of afferent firing induces LTP in neurogliaform interneurons identified using neuron-derived neurotrophic factor (Ndnf)-Cre mice. Theta-burst activity of entorhinal cortex afferents led to an increase in disynaptic feed-forward inhibition, but not monosynaptic excitation, of CA1 pyramidal neurons. Activity-dependent synaptic plasticity in stratum lacunosum-moleculare interneurons thus alters the excitation-inhibition balance at entorhinal cortex inputs to the apical dendrites of pyramidal neurons, implying a dynamic role for these interneurons in gating CA1 dendritic computations. Abstract figure legend Hebbian LTP of excitatory transmission onto interneurons located within hippocampal stratum lacunosum moleculare (SLM) can be induced by electrical stimulation protocols involving pairing of pre-and post-synaptic activity. Using Ndnf-Cre mice, we show that hippocampal neurogliaform (NGF) cells express this form of LTP. These cells receive glutamatergic afferents from both the nucleus reuniens of the thalamus and the entorhinal cortex (EC), but selective optogenetic activation of either set of fibers reveals LTP at EC inputs only. Using an optogenetic theta-burst stimulation (OptoTBS) protocol to stimulate EC fibers in a physiologically relevant way, we show that NGF interneuron LTP translates to an increase in disynaptic inhibition onto CA1 pyramidal cell distal dendrites. Monosynaptic EC-CA1 pyramidal cell inputs do not undergo equivalent potentiation, leading to a net decrease in the excitation/inhibition (E/I) ratio of this pathway

    First dating results for the Middle Pleistocene industries (Acheulean – Early Middle Palaeolithic) in the Pyrenees – Garonne region: a multi methods geochronological approach (TL, OSL and TT-OSL) of the Duclos and Romentères sites

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    The recent development work of the A65 highway has given the opportunity to broaden the corpus of Lower and Middle Palaeolithic open-air sites known in the southern Aquitaine basin. The sites of Duclos (Auriac, Pyrénées-Orientales) and Romentères (Le Vignau, Landes), discovered in this context, have yielded an abundant lithic record which has been attributed to the Acheulean of Iberian type for the earlier and, essentially, to the Early Middle Palaeolithic for the latter. The archaeological levels are intercalated in sequences that comprise aeolian silts and colluvial units separated by interglacial luvisols. The pedostratigraphic context of the two sites has provided a rare opportunity to propose a reliable chronostratigraphic framework in this area. To achieve this objective, a study combining several methods of luminescence dating was conducted to complete the geomorphological data. Optically Stimulated Luminescence (OSL) and Thermically Transferred OSL (TT-OSL) dating methods were applied in order to determine the ages of sedimentary quartz grains and thus, of the sampled deposits. In parallel, heated flint and quartzite samples were dated by thermoluminescence (TL). The Pyrenees-Garonne Acheulean industry of Duclos has been attributed to the boundary between Marine Isotopic Stages (MIS) 7 and 6 while the human occupations of Romentères date from MIS 6 for the most recent series (Early Middle Palaeolithic) and from MIS 9 and 8 for the older

    Diffraction limited optics for single atom manipulation

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    We present an optical system designed to capture and observe a single neutral atom in an optical dipole trap, created by focussing a laser beam using a large numerical aperture N.A.=0.5 aspheric lens. We experimentally evaluate the performance of the optical system and show that it is diffraction limited over a broad spectral range (~ 200 nm) with a large transverse field (+/- 25 microns). The optical tweezer created at the focal point of the lens is able to trap single atoms of 87Rb and to detect them individually with a large collection efficiency. We measure the oscillation frequency of the atom in the dipole trap, and use this value as an independent determination of the waist of the optical tweezer. Finally, we produce with the same lens two dipole traps separated by 2.2 microns and show that the imaging system can resolve the two atoms.Comment: 8 pages, 9 figures; typos corrected and references adde

    Simulation 2D thermomécanique des cartes de circuit imprimé avec composants enterrés

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    Depuis quelques années, dans le but d’augmenter la densité et les performances des cartes électroniques, des composants sont enfouis dans les couches internes de circuit imprimé. Une évaluation de la fiabilité de cette technologie est nécessaire avant utilisation au sein de cartes électroniques soumises à des environnements sévères pendant de longues durées. Afin d’étudier le comportement thermomécanique de ces cartes, des simulations par éléments finis ont été réalisées. Les composants enfouis sont soumis à un chargement thermomécanique complexe durant le procédé d’assemblage, notamment de flexion composée, due à un rétreint des résines et des préimprégnés

    Associated relaps factors in Le Fort I osteotomy. A retrospective study of 54 cases

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    PURPOSE: The Le Fort I osteotomy (LFI) procedure is commonly used to restore morpho-functional balance. The goal of maxillofacial surgeons with this procedure is to achieve occlusal stability. To identify factors associated with relapse after maxillary advancement in cleft lip and palate patients, the one-year post-operative stability of Le Fort I osteotomy was evaluated. METHODS: Horizontal and vertical relapse were analysed on lateral cephalograms by retrospectively using tracing paper in an orthonormal landmark in 54 patients undergoing unilateral cleft lip and palate surgery who were monitored at Nantes University Hospital. The lateral cephalograms were performed pre-operatively, immediately post-operatively, and after one year. Several variables were studied such as population data, intra-operative and post-operative surgical treatment, and surgical movement. RESULTS: At point A, the subspinale point, the mean advancement during surgery was 4.2 mm, with a relapse of 0.8 mm (20.1%). The mean downward movement was 2.0 mm in 26 patients who had a clockwise rotation of the maxilla, with a relapse of 0.6 mm (28.4%). The mean upward movement was 2.3 mm in 27 patients who had a counterclockwise rotation, with a deterioration of 0.2 mm (7%). A 7-millimetre surgical advancement corresponded to the threshold value beyond which relapse appeared to be significantly greater but still less than two millimetres in 75% of cases. CONCLUSION: The degree of advancement appears to be the only variable correlated with the amplitude of the relapse
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