Inner speech sustains predictable task switching: direct evidence in adults

It has been proposed that inner speech supports task selection in task-switching studies, especially when the need for endogenous control is increased. This has been established through the suppression of inner speech in cognitive-flexibility tasks that leads to poorer performance. The aim of this study is to quantify the role of inner speech in a flexibility task by using surface laryngeal electromyography, which, contrary to previous studies, enables participants to freely verbalise the tasks. We manipulated endogenous and exogenous flexibility in a mathematical switching task paradigm. Experiment 1 shows that inner speech acts as a support for switching and is recruited more often when the tasks are of an endogenous type. The main result of Experiment 2 that language is recruited more for the mixing cost than for the switch cost (regardless of the endogenous factor) extends past findings obtained through articulatory suppression

Observation of a Group of Dark Rogue Waves in a Telecommunication Optical Fiber

Over the past decade, the rogue wave debate has stimulated the comparison of predictions and observations among different branches of wave physics, particularly between hydrodynamics and optics, in situations where analogous dynamical behaviors can be identified, thanks to the use of common universal models. Although the scalar nonlinear Schroedinger equation (NLSE) has constantly played a central role for rogue wave investigations, moving beyond the standard NLSE model is relevant and needful for describing more general classes of physical systems and applications. In this direction, the coupled NLSEs are known to play a pivotal role for the understanding of the complex wave dynamics in hydrodynamics and optics. Benefiting from the advanced technology of high-speed telecommunication-grade components, and relying on a careful design of the nonlinear propagation of orthogonally-polarized optical pump waves in a randomly birefringent telecom fiber, this work explores, both theoretically and experimentally, the rogue wave dynamics governed by such coupled NLSEs. We report, for the first time, the evidence of a group of three dark rogue waves, the so-called dark three-sister rogue waves, where experiments, numerics, and analytics show a very good consistency

A dynamic explanation for the origin of the western Mediterranean organic-rich layers

The eastern Mediterranean sapropels are among the most intensively investigated phenomena in the paleoceanographic record, but relatively little has been written regarding the origin of the equivalent of the sapropels in the western Mediterranean, the organic-rich layers (ORLs). ORLs are recognized as sediment layers containing enhanced total organic carbon that extend throughout the deep basins of the western Mediterranean and are associated with enhanced total barium concentration and a reduced diversity (dysoxic but not anoxic) benthic foraminiferal assemblage. Consequently, it has been suggested that ORLs represent periods of enhanced productivity coupled with reduced deep ventilation, presumably related to increased continental runoff, in close analogy to the sapropels. We demonstrate that despite their superficial similarity, the timing of the deposition of the most recent ORL in the Alboran Sea is different than that of the approximately coincident sapropel, indicating that there are important differences between their modes of formation. We go on to demonstrate, through physical arguments, that a likely explanation for the origin of the Alboran ORLs lies in the response of the western Mediterranean basin to a strong reduction in surface water density and a shoaling of the interface between intermediate and deep water during the deglacial period. Furthermore, we provide evidence that deep convection had already slowed by the time of Heinrich Event 1 and explore this event as a potential agent for preconditioning deep convection collapse. Important differences between Heinrich-like and deglacial-like influences are highlighted, giving new insights into the response of the western Mediterranean system to external forcing

Elucidating the crystal-chemistry of Jbel Rhassoul stevensite (Morocco) by advanced analytical techniques

The composition of Rhassoul clay is controversial regarding the nature of the puremineral clay fraction which is claimed to be stevensite rather than saponite. In this study, the raw and mineral fractions were characterized using various techniques including Fourier transform infrared spectroscopy and magic angle spinning nuclear magnetic resonance (MAS NMR). The isolated fine clay mineral fraction contained a larger amount of Al (>1 wt.%) than that reported for other stevensite occurrences. The 27Al MAS NMR technique confirmed that the mineral is stevensite in which the Al is equally split between the tetrahedral and octahedral coordination sites. The 29Si NMR spectrum showed a single unresolved resonance indicating little or no short-range ordering of silicon. The chemical composition of the stevensite from Jbel Rhassoul was determined to be ((Na0.25K0.20 (Mg5.04Al0.37Fe0.20&0.21)5.61(Si7.76Al0.24)8O20(OH)4). This formula differs from previous compositions described from this locality and shows it to be an Al-bearing lacustrine clay mineral

La gestion actuelle de l'érosion par la végétation forestière dans les Alpes du sud.

Cet article fait le bilan des principaux résultats concernant la gestion de l'érosion par la forêt dans les Alpes du sud

Polarization modulation instability in a Manakov fiber system

The Manakov model is the simplest multicomponent model of nonlinear wave theory: It describes elementary stable soliton propagation and multisoliton solutions, and it applies to nonlinear optics, hydrodynamics, and Bose-Einstein condensates. It is also of fundamental interest as an asymptotic model in the context of the widely used wavelength-division-multiplexed optical fiber transmission systems. However, although its physical relevance was confirmed by the experimental observation of Manakov (vector) solitons in a planar waveguide in 1996, there have in fact been no quantitative experiments confirming its validity for nonlinear dynamics other than soliton formation. Here, we report experiments in optical fiber that provide evidence of passband and baseband polarization modulation instabilities in a defocusing Manakov system. In the spontaneous regime, we also reveal a unique saturation effect as the pump power increases. We anticipate that such observations may impact the application of this minimal model to describe and understand more complicated phenomena in nature, such as the formation of extreme waves in multicomponent systems

Pressure dependence of Raman modes in double wall carbon nanotubes filled with α-Fe.

The preparation of highly anisotropic one-dimensional (1D) structures confined into carbon nanotubes (CNTs) in general is a key objective in CNTs research. In this work, the capillary effect was used to fill double wall carbon nanotubes with iron. The samples are characterized by Mössbauer and Raman spectroscopy, transmission electron microscopy, scanning area electron diffraction, and magnetization. In order to investigate their structural stability and compare it with that of single wall carbon nanotubes (SWNTs), elucidating the differences induced by the inner-outer tube interaction, unpolarized Raman spectra of tangential modes of double wall carbon nanotubes (DWNTs) filled with 1D nanocrystallin α-Fe excited with 514 nm were studied at room temperature and elevated pressure. Up to 16 GPa we find a pressure coefficient for the internal tube of 4.3 cm−1 GPa−1 and for the external tube of 5.5 cm−1 GPa−1. In addition, the tangential band of the external and internal tubes broadens and decreases in amplitude. All findings lead to the conclusion that the outer tube acts as a protection shield for the inner tubes (at least up 16 GPa). Structural phase transitions were not observed in this range of pressure

The Benthic Boundary Layer: geochemical and oceanographic data from the GEOSTAR-2 observatory

Geochemical and oceanographic data, acquired throughout 6 months by the GEOSTAR-2 benthic observatory in southern Tyrrhenian Sea, evidenced ocean-lithosphere interactions in the 1900-m deep Benthic Boundary Layer (BBL), distinguishing two water masses with different origin and, possibly, benthic residence time. Gas concentration, helium isotopic ratios, radioactivity, temperature, salinity and vertical component of the current converged towards the indication of a BBL characterised by a colder and fresher western water (WW), which is episodically displaced by the cascading of the warmer and saltier Eastern Overflow Water (EOW). The benthic WW has higher concentration of geochemical tracers diffusing from the seafloor sediments. The data set shows the potential of long-term, continuous and multiparametric monitoring in providing unique information which cannot be acquired by traditional, short-term or single-sensor investigations

Preliminary In Vivo Studies of a New Injectable Bone Substitute

Calcium-phosphate materials have been increasingly employed in orthopedic and dental applications in recent years and are now being developed for use in noninvasive surgery or as carriers for drug delivery systems. We developed an injectable bone substitute (IBS) for percutaneous orthopedic surgery which uses a biphasic calcium-phosphate (BCP) mixture composed of hydroxyapatite (60%) and ß-tricalcium phosphate (40%), together with a polymer (hydroxy-propyl-methyl-cellulose, HPMC) as a carrier. The best BCP/polymer ratio was determined to achieve the highest mineral phase in the composite and provide the rheological properties required for injectable material. The in vivo biocompatibility and biofunctionality of IBS were tested in rabbits using implants in subcutaneous, intramuscular and cartilage sites and defects created in trabecular bone of the femur epiphysis. The defects were filled with IBS, and histological studies were performed after 1, 2, 4 and 12 weeks on decalcified and non-decalcified sections. Image analysis and backscattered electron analyses were performed by scanning electron microscopy. This study demonstrated that HPMC is a non-toxic material which can be associated with calcium-phosphates to produce an IBS and create a matrix for deep cell colonization conducive to bone ingrowth