1,773 research outputs found

    Changing ideas about others' intentions: updating prior expectations tunes activity in the human motor system

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    Predicting intentions from observing another agent’s behaviours is often thought to depend on motor resonance – i.e., the motor system’s response to a perceived movement by the activation of its stored motor counterpart, but observers might also rely on prior expectations, especially when actions take place in perceptually uncertain situations. Here we assessed motor resonance during an action prediction task using transcranial magnetic stimulation to probe corticospinal excitability (CSE) and report that experimentally-induced updates in observers’ prior expectations modulate CSE when predictions are made under situations of perceptual uncertainty. We show that prior expectations are updated on the basis of both biomechanical and probabilistic prior information and that the magnitude of the CSE modulation observed across participants is explained by the magnitude of change in their prior expectations. These findings provide the first evidence that when observers predict others’ intentions, motor resonance mechanisms adapt to changes in their prior expectations. We propose that this adaptive adjustment might reflect a regulatory control mechanism that shares some similarities with that observed during action selection. Such a mechanism could help arbitrate the competition between biomechanical and probabilistic prior information when appropriate for prediction

    Hybridizing Lead-Acid Batteries with Supercapacitors: A Methodology

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    Hybridizing a lead–acid battery energy storage system (ESS) with supercapacitors is a promising solution to cope with the increased battery degradation in standalone microgrids that suffer from irregular electricity profiles. There are many studies in the literature on such hybrid energy storage systems (HESS), usually examining the various hybridization aspects separately. This paper provides a holistic look at the design of an HESS. A new control scheme is proposed that applies power filtering to smooth out the battery profile, while strictly adhering to the supercapacitors’ voltage limits. A new lead–acid battery model is introduced, which accounts for the combined effects of a microcycle’s depth of discharge (DoD) and battery temperature, usually considered separately in the literature. Furthermore, a sensitivity analysis on the thermal parameters and an economic analysis were performed using a 90-day electricity profile from an actual DC microgrid in India to infer the hybridization benefit. The results show that the hybridization is beneficial mainly at poor thermal conditions and highlight the need for a battery degradation model that considers both the DoD effect with microcycle resolution and temperate impact to accurately assess the gain from such a hybridization

    Understanding the Effects of a Tannin Extract on Forage Protein Digestion in the Rumen and Abomasum Using a Dynamic Artificial Digestive System Coupled to a Digestomic Approach

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    Improving the use efficiency of dietary protein in ruminants is a major challenge to decrease feed supplementation and significantly decrease nitrogen (N) losses to the environment. The aim of this study was to characterize the effects of tannins on protein digestion in the rumen and in conditions simulating the abomasum, using a dynamic in vitro digestive system coupled to a digestomic approach. Three ruminally-cannulated sheep fed with alfalfa hay were infused daily with a solution of tannins, while three other sheep were infused with water (control). Standardized ruminal fluid was introduced into the digester, which simulated the transit of digesta under physicochemical conditions mimicking the abomasum in terms of pH regulation, digestive enzyme infusions and transit rate. Protein degradation in the rumen and in the simulated abomasum was analyzed by determination of fermentation end-products, and identification and quantification of peptides (Label Free Quantification) by LC-MS/MS high resolution (Orbitrap). The analysis of rumen samples showed that tannins result in a clear decrease of fermentation end-products related to protein degradation, namely ammonia (NH3) and iso-volatile fatty acids (VFA), and a greater abundance of the Rubisco, a major plant protein. In the simulated abomasal compartment, the peptidomic analysis showed that the hydrolysis intensity of Rubisco was higher in the presence of tannins compared to the control group. These results indicate that protein-tannin complexes could be dissociated in the physico-chemical conditions of the abomasum, increasing the flow of peptides to the intestine after protection of protein by tannins in the rumen

    Role of highly branched, high molecular weight polymer structures in directing uniform polymer particle formation during nanoprecipitation

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    The new macromolecular architecture, hyperbranched polydendrons, are composed of a broad distribution of molecular weights and architectural variation; however, nanoprecipitation of these materials yields highly uniform, dendron-functional nanoparticles. By isolating different fractions of the diverse samples, the key role of the most highly branched structures in directing nucleation and growth has been explored and determined.</div

    New electronic orderings observed in cobaltates under the influence of misfit periodicities

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    We study with ARPES the electronic structure of CoO2 slabs, stacked with rock-salt (RS) layers exhibiting a different (misfit) periodicity. Fermi Surfaces (FS) in phases with different doping and/or periodicities reveal the influence of the RS potential on the electronic structure. We show that these RS potentials are well ordered, even in incommensurate phases, where STM images reveal broad stripes with width as large as 80\AA. The anomalous evolution of the FS area at low dopings is consistent with the localization of a fraction of the electrons. We propose that this is a new form of electronic ordering, induced by the potential of the stacked layers (RS or Na in NaxCoO2) when the FS becomes smaller than the Brillouin Zone of the stacked structure

    Murine isoforms of retinoic acid receptor gamma with specific patterns of expression.

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    We have characterized seven murine retinoic acid receptor gamma cDNA isoforms (mRAR-gamma 1 to -gamma 7) generated by alternative splicing of at least seven exons. These isoforms differ from one another in their 5' untranslated region and in two cases (mRAR-gamma 1 and -gamma 2) differ in their N-terminal A region, which is known to be important for differential transactivation by other nuclear receptors. mRAR-gamma 1 and -gamma 2, the predominant isoforms, are differentially expressed in adult tissues and during embryogenesis. Most notably, skin contains almost exclusively mRAR-gamma 1 transcripts. The conservation of the RAR-gamma isoforms from mouse to human together with their patterns of expression suggests that they perform specific functions, which may account for the pleiotropic effect of retinoic acid in embryogenesis and development

    High-resolution microwave frequency dissemination on an 86-km urban optical link

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    We report the first demonstration of a long-distance ultra stable frequency dissemination in the microwave range. A 9.15 GHz signal is transferred through a 86-km urban optical link with a fractional frequency stability of 1.3x10-15 at 1 s integration time and below 10-18 at one day. The optical link phase noise compensation is performed with a round-trip method. To achieve such a result we implement light polarisation scrambling and dispersion compensation. This link outperforms all the previous radiofrequency links and compares well with recently demonstrated full optical links.Comment: 11 pages, 5 figure
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