Formation of Pd2Si on single-crystalline Si (100) at ultrafast heating rates : an in-situ analysis by nanocalorimetry

The kinetics of intermediate phase formation between ultrathin films of Pd (12 nm) and single-crystalline Si (100) is monitored by in-situ nanocalorimetry at ultrafast heating rates. The heat capacity curves show an exothermic peak related to the formation of Pd2Si. A kinetic model which goes beyond the conventional linear-parabolic growth to consider independent nucleation and lateral growth of Pd2Si along the interface and vertical growth mechanisms is developed to fit the calorimetric curves. The model is used to extract the effective interfacial nucleation/growth and diffusion coefficients at the unusually high temperatures of silicide formation achieved at very fast heating rates

New lithostratigraphy for the Cantabrian Mountains: A common tectono-stratigraphic evolution for the onset of the Alpine cycle in the W Pyrenean realm, N Spain

The Pyrenean-Cantabrian Orogen arose through the collision of the Iberian and Eurasian plates, mostly in Cenozoic times. This orogen comprises two main mountain ranges, the Pyrenees to the east, and the Cantabrian Mountains to the west. To date, the early Alpine tectono-sedimentary phases preserved in the Cantabrian Mountains, of Permian and Triassic age, have been considered independently from the same phases in neighbouring basins of SW Europe, and even from the eastern part of the same orogeny (the Pyrenean orogeny). In consequence, the beginning of the Alpine cycle in the Cantabrian Mountains has been interpreted within a specific geodynamic context, far from the general evolutionary phases of the western Peri-Tethys basins. Through detailed field work, including geological mapping, sedimentology, lithostratigraphy and petrology of volcanic rocks, and new palaeontological data, here we define several new lithostratigraphical formations and five new tectono-sedimentary cycles (TS I-V) for the initial phases of evolution of the Mesozoic Basque-Cantabrian Basin, interrupted by periods of tectonic stability. To complete this information, we include data from an onshore borehole (Villabona Mine) and two offshore boreholes constrained by 2D reflection seismic profiles acquired in the North Iberian continental platform. The main tectono-sedimentary cycles, related to the deposition of five major identified lithostratigraphic units, can be described as follows: TS I (late Gzelian-early Asselian), relating to the late Variscan deformation and preserved in a single outcrop in all the Cantabrian Mountains (San Tirso Formation). This formation is constituted by medium-distal alluvial fan deposits in which humid intervals predominate, forming some thin coal beds. TS II (Asselian-Sakmarian), a post-Variscan extensional phase with associated calc-alkaline magmatism, represented by profuse volcanic and volcanosedimentary intercalations in the early Permian sedimentary basins (Acebal Formation) and small plutons in surrounding areas. TS III (Kungurian), or reactivation of the post-Variscan extension leading to alluvial and lacustrine carbonate sedimentation in arid climate conditions, which do not change during the rest of the Permian and Triassic periods (Sotres Formation). A generalized karstification in the basin represents the end of Permian deposition, followed by an interruption in sedimentation longer than 30 Myr. The Permian tectono-sedimentary cycles (TS II and TS III) are contemporary with Variscan belt collapse and the basins are controlled by extensional reactivation of NE-SW and E-W Variscan structures, and NW-SE late Variscan structures. TS IV (late Anisian–middle Carnian), renewed sedimentation in more extensive basins, precursors of the great Mesozoic Basque-Cantabrian Basin. This cycle is represented by fluvial deposits (Cicera Formation, or Buntsandstein facies), which are interrupted by the first Mesozoic marine ingression (Rueda Formation, or Muschelkalk facies). TS V (Norian-Rhaetian), or shallow marine carbonate deposits (Transición Formation) related to increasingly compartmentalized sub-basins, controlled by normal faults. This final TS is broadly connected with different basins of the western Peri-Tethys domain. The identification of units TS I-V in the Cantabrian Mountains along with the volcanic character of TS II, all indicate the development of a common post-Variscan to early Alpine tectono-sedimentary evolution for the whole Pyrenean-Cantabrian realm

Estructura y evolución tectónica del sector oriental del margen continental cantábrico: resultados de los perfiles de sísmica multicanal MARCONI

El Golfo de Vizcaya se formó durante el Cretácico como consecuencia de la apertura del Océano Atlántico. La convergencia entre las placas Euroasiática e Ibérica durante el Cenozoico dio lugar al levantamiento de la cordillera pirenaico-cantábrica y al cierre parcial del Golfo de Vizcaya. La mayor parte de esta deformación tiene lugar en el margen Noribérico, haciendo de este área un lugar único para estudiar los estadios iniciales de la deformación de un margen pasivo. En el verano de 2003, el experimento sísmico MARCONI permitió adquirir 11 perfiles de sísmica de reflexión vertical profunda utilizando el buque Hespérides, lo que ha proporcionado una nueva imagen 3D de la estructura cortical del sector SE del Golfo de Vizcaya. Los datos muestran que la estructura de este margen se caracteriza por una espesa secuencia de sedimentos meso-cenozoicos (hasta 4 s TWT, hasta > 6 km) parcialmente deformada por cabalgamiento y pliegues asociados, vergentes al N. Se han diferenciado tres conjuntos sedimentarios separados por discordancias que se corresponden con las secuencias alpinas pre-, sin- y postectónicas. Los datos sísmicos muestran también la existencia de cuencas mesozoicas con evidencias de inversión tectónica y la existencia de fallas y estructuras laterales coincidiendo con los importantes cañones submarinos de dirección aproximada N-S. Teniendo tambien en cuenta otros datos geofísicos, la estructura general del sector SE del Golfo de Vizcaya se ha interpretado como una corteza continental adelgazada o transicional deslizada hacia el S por debajo del extremadamente abrupto y muy deformado talud continental Noribérico

Cenozoic deformation of Iberia: a model for intraplate mountain building and basin development based on analogue modelling

Inferences from analogue models support lithospheric folding as the primary response to large-scale shortening manifested in the present day topography of Iberia. This process was active from the late Oligocene-early Miocene during the Alpine orogeny and was probably enhanced by reactivation of inherited Variscan faults. The modeling results confirm the dependence of fold wavelength on convergence rate and hence the strength of the layers of the lithosphere such that fold wavelength is longest for fast convergence rates favoring whole lithosphere folding. Folding is associated with the formation of dominantly pop-up type mountain ranges in the brittle crust and thickening of the ductile layers in the synforms of the buckle folds by flow. The mountain ranges are represented by upper crustal pop-ups forming the main topographic relief. The wavelengths of the topographic uplifts, both, in model and nature suggest mechanical decoupling between crust and mantle. Moreover, our modeling results suggest that buckling in Iberia took place under rheological conditions where the lithospheric mantle is stronger than the lower crust. The presence of an indenter, inducing oblique shortening in response to the opening of the King's Trough in the north western corner of the Atlantic Iberian margin controls the spacing and obliquity of structures. This leads to the transfer of the deformation from the moving walls towards the inner part of the model, creating oblique structures in both brittle and ductile layers. The effect of the indenter, together with an increase on the convergence rate produced more complex brittle structures. These results show close similarities to observations on the general shape and distribution of mountain ranges and basins in Iberia, including the Spanish Central System and Toledo Mountains.Peer reviewe

State recognition for ‘contested languages’: a comparative study of Sardinian and Asturian, 1992–2010

While the idea of a named language as a separate and discrete identity is a political and social construct, in the cases of Sardinian and Asturian doubts over their respective ‘languageness’ have real material consequences, particularly in relation to language policy decisions at the state level. The Asturian example highlights how its lack of official status means that it is either ignored or subjected to repeated challenges to its status as a language variety deserving of recognition and support, reflecting how ‘official language’ in the Spanish context is often understood in practice as synonymous with the theoretically broader category of ‘language’. In contrast, the recent state recognition of Sardinian speakers as a linguistic minority in Italy (Law 482/1999) illustrates how legal recognition served to overcome existing obstacles to the implementation of regional language policy measures. At the same time, the limited subsequent effects of this Law, particularly in the sphere of education, are a reminder of the shortcomings of top-down policies which fail to engage with the local language practices and attitudes of the communities of speakers recognized. The contrastive focus of this article thus acknowledges the continued material consequences of top-down language classification, while highlighting its inadequacies as a language policy mechanism which reinforces artificial distinctions between speech varieties and speakers deserving of recognition

Lithospheric geometry of the Wopmay orogen from a Slave craton to Bear Province magnetotelluric transect

Two‐dimensional inversions of lithospheric‐probing magnetotelluric (MT) data at a total of 20 sites acquired along an approximately east–west 300‐km‐long profile across the Wopmay orogen in the Northwest Territories, Canada, provide electrical resistivity models of the boundary between the Archean Slave craton and the adjacent Proterozoic Bear Province. An analysis of distortion effects and structural dimensionality indicates that the MT responses are primarily one‐dimensional or only weakly two‐dimensional with a depth‐independent geoelectric strike angle of N32°E, consistent with regional structural geology. The regional‐scale model, generated from the longer period responses from all of the sites along the profile, reveals significant lateral variations in the lithospheric mantle. Resistive cratonic roots are imaged to depths of ∼200 km beneath both the Slave craton and the Hottah terrane of the Bear Province. These are separated by a less resistive region beneath the Great Bear magmatic zone, which is speculatively interpreted as a consequence of a decrease in the grain size of olivine in the Wopmay mantle, caused by localized shearing, compared to its neighboring cratonic roots. Focused two‐dimensional models, from higher frequency responses at sites on specific sections of the profile, reveal the resistivity structure at crustal depths beneath the region. These suggest that the root of the Slave craton crosses beneath the Wopmay orogen, and that the Wopmay fault zone does not penetrate into the lower crust. A comparison of these results with those obtained during the Lithoprobe project farther south shows striking along strike variations in the conductivity structure associated with the Wopmay orogen

Spatiotemporal variation of the epifaunal assemblages associated to Sargassum muticum on the NW Atlantic coast of Morocco

Epifaunal assemblages inhabiting the non-indigenous macroalga Sargassum muticum (Yendo) Fensholt were investigated on two physically distinct intertidal rocky (S1) and sandy (S2) sites along the Atlantic coast of Morocco. The objective of this study was to test whether the habitat-forming marine alga S. muticum invasive in these sites supported different epifaunal assemblages under different environmental conditions and through time. The gastropods Steromphala umbilicalis, S. pennanti, and Rissoa parva and the isopod Dynamene bidentata were the most contributive species to the dissimilarity of epifaunal assemblage structure between both sites throughout seasons. SIMPER analysis showed a dissimilarity of 58.3-78.5% in the associated species composition of S. muticum between study sites with respect to sampling season. Species diversity and total abundance were significantly higher at the rocky site compared to the sandy site. PERMANOVA analyses showed significant differences of associated epifaunal assemblage structure for the season and site interaction. Accordingly, site and season were determinant factors conditioning the role of habitat in structuring epifaunal assemblages.info:eu-repo/semantics/publishedVersio

A Method for the Generation of Ectromelia Virus (ECTV) Recombinants: In Vivo Analysis of ECTV vCD30 Deletion Mutants

Ectromelia virus (ECTV) is the causative agent of mousepox, a lethal disease of mice with similarities to human smallpox. Mousepox progression involves replication at the initial site of infection, usually the skin, followed by a rapid spread to the secondary replicative organs, spleen and liver, and finally a dissemination to the skin, where the typical rash associated with this and other orthopoxviral induced diseases appears. Case fatality rate is genetically determined and reaches up to 100% in susceptible mice strains. Like other poxviruses, ECTV encodes a number of proteins with immunomodulatory potential, whose role in mousepox progression remains largely undescribed. Amongst these is a secreted homologue of the cellular tumour necrosis factor receptor superfamily member CD30 which has been proposed to modulate a Th1 immune response in vivo

Formation and deformation of hyperextended rift systems: Insights from rift domain mapping in the Bay of Biscay-Pyrenees

International audienceThe Bay of Biscay and the Pyrenees correspond to a Lower Cretaceous rift system including both oceanic and hyperextended rift domains. The transition from preserved oceanic and rift domains in the West to their complete inversion in the East enables us to study the progressive reactivation of a hyperextended rift system. We use seismic interpretation, gravity inversion, and field mapping to identify and map former rift domains and their subsequent reactivation. We propose a new map and sections across the system illustrating the progressive integration of the rift domains into the orogen. This study aims to provide insights on the formation of hyperextended rift systems and discuss their role during reactivation. Two spatially and temporally distinct rift systems can be distinguished: the Bay of Biscay-Parentis and the Pyrenean-Basque-Cantabrian rifts. While the offshore Bay of Biscay represent a former mature oceanic domain, the fossil remnants of hyperextended domains preserved onshore in the Pyrenean-Cantabrian orogen record distributed extensional deformation partitioned between strongly segmented rift basins. Reactivation initiated in the exhumed mantle domain before it affected the hyperthinned domain. Both domains accommodated most of the shortening. The final architecture of the orogen is acquired once the conjugate necking domains became involved in collisional processes. The complex 3-D architecture of the initial rift system may partly explain the heterogeneous reactivation of the overall system. These results have important implications for the formation and reactivation of hyperextended rift systems and for the restoration of the Bay of Biscay and Pyrenean domain