Neural basis of implicit motor sequence learning : Modulation of cortical power

Implicit sequence learning describes the acquisition of serially ordered movements and sequentially structured cognitive information, that occurs without awareness. Theta, alpha and beta cortical oscillations are present during implicit motor sequence learning, but their role in this process is unclear. The current study addressed this gap in the literature. A total of 50 healthy adults aged between 19 and 37 years participated in the study. Implicit motor sequence learning was examined using the Serial Reaction Time task where participants unknowingly repeat a sequence of finger movements in response to a visual stimulus. Sequence learning was examined by comparing reaction times and oscillatory power between sequence trials and a set of control trials comprising random stimulus presentations. Electroencephalography was recorded as participants completed the task. Analyses of the behavioral data revealed participants learnt the sequence. Analyses of oscillatory activity, using permutation testing, revealed sequence learning was associated with a decrease in theta band (4–7 Hz) power recorded over frontal and central electrode sites. Sequence learning effects were not observed in the alpha (7–12 Hz) or beta bands (12–20 Hz). Even though alpha and beta power modulations have long been associated with executing a motor response, it seems theta power is a correlate of sequence learning in the manual domain. Theta power modulations on the serial reaction time task may reflect disengagement of attentional resources, either promoting or occurring as a consequence of implicit motor sequence learnin

Lago Mare and the Messinian Salinity Crisis: Evidence from the Alboran Sea (S. Spain)

International audienceThis paper provides a new environmental, sedimentological and stratigraphic context of the Lago Mare deposits from the North Alboran region and clarifies their chronologic location with respect to the Messinian Salinity Crisis. We present new micropaleontological data (dinoflagellate cysts, calcareous nannoplankton, planktonic foraminifers), correlated with field observations and offshore seismic interpretations. We show that the Lago Mare event known in three onshore localities (Río Mendelín near Malaga, Zorreras near Sorbas, Gafares near Níjar) follows the marine reflooding of the Mediterranean Basin which ended the Messinian Salinity Crisis. Chronologically, these Lago Mare deposits last from the latest Messinian to the early Zanclean. In fact, the first influx of Paratethyan- organisms is revealed by the dinoflagellate cyst record from near Malaga within a Gilbert-type fan delta overlying the Messinian Erosional Surface. Invading molluscs and/or ostracods may have persisted in lagoonal coastal areas more or less affected by discontinuous marine influxes (Sorbas and Níjar). The Malaga area is convenient for a paleogeographic and sedimentary reconstruction which shows the prevalent forcing of sea level changes during the time-interval 5.600-5.332 Ma at the difference of the usually solicited prevalent tectonics. The studied Lago Mare event is the third episode resulting in such a paleobiological assemblage in the Mediterranean region and corresponds to the final two-way water exchange at high sea level between the Mediterranean and the former Paratethys. It documents the onset of the modern marine circulation in the Mediterranean after the reflooding ending the Messinian Salinity Crisis

Data on lithofacies, sedimentology and palaeontology of South Rifian Corridor sections (Morocco)

We provide lithological, sedimentological and micropalaeontological descriptions of 39 sections and boreholes crossing the upper Miocene deposits of the Rifian Corridor. These deposits represent the sedimentary remnants of the marine gateway that connected the Atlantic to the Mediterranean in the late Miocene. Results from these 39 sites were adopted to reconstruct the palaeogeographic evolution of the gateway presented in the associated research article (Capella et al., 2018) [1]. For each outcrop we present a synthesis of field observations, lithofacies, key sedimentological features, planktic and benthic assemblages

Contourite depositional system after the exit of a strait: Case study from the late Miocene South Rifian Corridor, Morocco

Idealized facies of bottom current deposits (contourites) have been established for fine-grained contourite drifts in modern deep-marine sedimentary environments. Their equivalent facies in the ancient record however are only scarcely recognized due to the weathered nature of most fine-grained deposits in outcrop. Facies related to the erosional elements (i.e. contourite channels) of contourite depositional systems have not yet been properly established and related deposits in outcrop appear non-existent. To better understand the sedimentary facies and facies sequences of contourites, the upper Miocene contourite depositional systems of the South Rifian Corridor (Morocco) is investigated. This contourite depositional system formed by the dense palaeo-Mediterranean Outflow Water. Foraminifera assemblages were used for age-constraints (7.51 to 7.35 Ma) and to determine the continental slope depositional domains. Nine sedimentary facies have been recognized based on lithology, grain-size, sedimentary structures and biogenic structures. These facies were subsequently grouped into five facies associations related to the main interpreted depositional processes (hemipelagic settling, contour currents and gravity flows). The vertical sedimentary facies succession records the tectonically induced, southward migration of the contourite depositional systems and the intermittent behaviour of the palaeo-Mediterranean Outflow Water, which is mainly driven by precession and millennial-scale climate variations. Tides substantially modulated the palaeo-Mediterranean Outflow Water on a sub-annual scale. This work shows exceptional examples of muddy and sandy contourite deposits in outcrop by which a facies distribution model from the proximal continental slope, the contourite channel to its adjacent contourite drift, is proposed. This model serves as a reference for contourite recognition both in modern environments and the ancient record. Furthermore, by establishing the hydrodynamics of overflow behaviour a framework is provided that improves process-based interpretation of deep-water bottom current deposits

Comportement electrochimique du niobrium et du tantale dans les bains de chlorures et chlorofluorures alcalins fondus

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : T 79271 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Influence des transferts aérauliques dans les parois sur leurs performances thermiques

La consommation énergétique dun bâtiment a été jusquici estimée en négligeant les échanges de chaleur qui peuvent intervenir lorsque lair sinfiltre à travers son enveloppe. Or, des études récentes ([Bhattacharyya, 1995], [Buchanan, 2000] et [Janssens, 1988]) ont montré que ces fuites dair jouent un rôle significatif, non seulement sur les performances thermiques des parois et sur la consommation énergétique, mais aussi en terme de pathologies des constructions (condensations internes et superficielles), ou encore en terme de confort et de santé des occupants. Notre étude vise à évaluer, à laide dune approche numérique, leffet des transferts dair parasite dans les parois sur leur performance thermique et à quantifier la part réelle des déperditions de chaleur liées aux fuites dair. Dans la première partie de notre étude, nous passons en revue les causes des fuites dair et leurs techniques de mesure puis nous exposons les travaux traitant le problème du passage des fuites dans lenveloppe et montrons leurs limites. Dans le deuxième chapitre, nous présentons des simulations numériques basées sur les codes de champs ou codes CFD permettant détudier le transfert couplé dair et de chaleur au sein dune paroi multicouche comportant un isolant thermique poreux. Linteraction air/paroi se traduit par un changement du flux de conduction (ou bien du coefficient U de la paroi). Le troisième chapitre est consacré à lélaboration dun modèle de calcul se basant sur lhypothèse que la paroi traversée par lair peut être assimilée à un échangeur de chaleur. Lair traversant un canal noyé dans la paroi cède ou récupère de la chaleur au contact de la paroi. Les résultats issus des simulations CFD concordent avec ceux issus du modèle pour les deux types de fuites, cest à dire linfiltration et lexfiltration. En complément du développement des simulations CFD et du modèle de calcul, nous analysons deux cas détudes représentant deux catégories de bâtiments : une maison individuelle et un bâtiment tertiaire (bâtiment dun lycée). Cette étude a pour objectif dapporter une vue concrète et plus globale sur les conséquences des fuites sur le bilan énergétique. Ces calculs ont montré quune part importante des déperditions par transmission, caractérisées par le coefficient Ubât, peut être directement imputée aux fuites dair : jusquà 8 % pour la maison et 12 % pour le bâtiment Internat. Cette étude a également montré que les différentes parties de lenveloppe se trouvent affectées de façon inégale par les fuites dair (certaines parties sont affectées par linfiltration, dautre par lexfiltration). Nous en déduisons des recommandations de réhabilitation ou de colmatage de certaines parties de lenveloppe permettant de limiter leffet des fuites. Par exemple, nous recommandons dapporter un soin particulier aux étages supérieurs qui sont soumis à des fuites plus importantes, donc plus pénalisantes que celles affectant les étages inférieurs

Les foraminiferes planctoniques du Neogene du bassin de Boudinar (Rif Nord Oriental, Maroc). Biostratigraphie, systematique et paleoecologie

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : T 81840 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Magical realism as postcolonial discourse: magic, the carnivalesque and hybridity in Ben Okri's Abiku trilogy

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Filología, Departamento de Filología Inglesa II , leída el 06/03/2013. Tesis retirada por expreso deseo del autor el 3/07/2014Depto. de Estudios Ingleses: Lingüística y LiteraturaFac. de FilologíaTRUEunpu