The local adsorption geometry of benzenethiolate on Cu(1 0 0)

The local adsorption geometry of benzenethiolate in the ordered c(2 × 6) phase on Cu(1 0 0) has been investigated by a combination of S K-edge near-edge X-ray absorption fine structure (NEXAFS), normal incidence X-ray standing waves (NIXSW) and S 1s scanned-energy mode photoelectron diffraction (PhD). NEXAFS and PhD show that the molecular plane is tilted from the surface normal by 20 ± 15°, while NIXSW clearly identifies the S head-group as occupying the four-fold coordinated hollow sites. PhD shows the S atoms lies 1.34 ± 0.04 Å above the outermost Cu atomic layer, leading to a Cu–S bondlength of 2.25 ± 0.02 Å. The combination of the PhD and NIXSW results shows the Cu surface layer has an outward relaxation of 0.15 ± 0.06 Å. Possible origins for this large adsorbate-induced relaxation are discussed

Influencia del consumo de DHA en mujeres embarazadas sobre el peso del recién nacido, duración del tiempo de gestación y depresión posparto.

Diferentes estudios han analizado los posibles efectos del consumo de ácidos grasos omega-3, principalmente Ácido Docosahexaenoico (DHA), durante el embarazo dado que la ingesta y el conocimiento sobre la importancia de éste en dicha etapa biológica es generalmente escaso. Este es un estudio correlacional experimental, donde se analizaron 36 mujeres embarazadas, que voluntariamente se sumaron al proyecto, a partir de los 20 años de edad que concurrían al CIC Nº 919 de General Alvear, Mendoza. Se analizaron variables antropométricas, estilo de vida, indicadores dietéticos y escala de depresión postparto. Para el análisis estadístico se utilizaron los programas PASW Statistics 18.0 y GraphPad Prism 6 para Windows. Ninguna de las mujeres conocía los beneficios de DHA en el embarazo. Luego de la intervención nutricional, se encontró una correlación positiva sobre el consumo de DHA y menor prevalencia de depresión postparto, si bien no todas adhirieron a la ingesta ni lograron un consumo mínimo recomendable de 200mg DHA/día. No se observaron efectos de este consumo con respecto al peso del recién nacido ni duración de la gestación. De este estudio se resalta la importancia de la intervención nutricional temprana en mujeres embarazadas, para lograr, al menos, la ingesta mínima recomendada y obtener mayores beneficios del consumo de DHA

Resonances de forme des molecules organosoufrees: CH_3SH, C_2H_5SH, C_6H_5SH, CH_3SCH_3, C_2H_5SC_2H_5, C_56H_5SCH_3, CH_3SCN et CH_3NCS: spectroscopie de photoabsorption X, transmission d'electrons de basse energie, approche quantique

SIGLEINIST T 77663 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

New interactive strategies for virtual reality streaming in degraded context of use

International audienceVirtual reality videos are an important element in the range of immersive contents as they open new perspectives for story-telling, journalism or education. Accessing these immersive contents through Internet streaming is however much more difficult owing to the required data rates much higher than for regular videos. While current streaming strategies rely on video compression, in this paper we investigate a radically new stance: we posit that degrading the visual quality is not the only choice to reduce the required data rate, and not necessarily the best. Instead, we propose two new impairments, Virtual Walls (VWs) and Slow Downs (SDs), that change the way the user can interact with the 360 degree video in an environment with insufficient available bandwidth. User experiments with a double-stimulus approach show that, when triggered in proper time periods, these impairments are better perceived than visual quality degradation from video compression. We confirm with network simulations the usefulness of these new types of impairments: incorporated into a FoV-based adaptation, they can enable reduction in stalls and startup delay, and increase quality in FoV, even in the presence of substantial playback buffers