We present an overview of protein dynamics based mostly on results of neutron scattering, dielectric relaxation spectroscopy and molecular dynamics simulations. We identify several major classes of ...protein motions on the time scale from faster than picoseconds to several microseconds, and discuss the coupling of these processes to solvent dynamics. Our analysis suggests that the microsecond backbone relaxation process might be the main structural relaxation of the protein that defines its glass transition temperature, while faster processes present some localized secondary relaxations. Based on the overview, we formulate a general picture of protein dynamics and discuss the challenges in this field.
Reading Covered Faces Pavlova, Marina A; Sokolov, Arseny A
Cerebral cortex (New York, N.Y. 1991),
01/2022, Letnik:
32, Številka:
2
Journal Article
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Abstract
Covering faces with masks, due to mandatory pandemic safety regulations, we can no longer rely on the habitual daily-life information. This may be thought-provoking for healthy people, but ...particularly challenging for individuals with neuropsychiatric and neurodevelopmental conditions. Au fait research on reading covered faces reveals that: 1) wearing masks hampers facial affect recognition, though it leaves reliable inferring basic emotional expressions; 2) by buffering facial affect, masks lead to narrowing of emotional spectrum and dampen veridical evaluation of counterparts; 3) masks may affect perceived face attractiveness; 4) covered (either by masks or other veils) faces have a certain signal function introducing perceptual biases and prejudices; 5) reading covered faces is gender- and age-specific, being more challenging for males and more variable even in healthy aging; 6) the hampering effects of masks on social cognition occur over the globe; and 7) reading covered faces is likely to be supported by the large-scale assemblies of the neural circuits far beyond the social brain. Challenges and limitations of ongoing research and parallels to the Reading the Mind in the Eyes Test are assessed. Clarification of how masks affect face reading in the real world, where we deal with dynamic faces and have entrée to additional valuable social signals such as body language, as well as the specificity of neural networks underlying reading covered faces calls for further tailored research.
In this article, we discuss the extension of the Melvin solution for the geon to some models of non-linear electrodynamics with the exact form of the Lagrangian, in particular, for a conformally ...invariant model (CNED), whose Lagrangian depends on the second and fourth order invariants of the electromagnetic field tensor.
We present a brief overview of current developments in the field of polymer electrolytes, with the focus on single-ion conducting polymers. The latter have significant advantages relative to ...electrolytes with dual-ion conductivity for use in energy storage devices. First we discuss various mechanisms of ionic conductivity in polymers and fundamental limitations imposed by these mechanisms. We also emphasize the role of ion–ion correlations in conductivity that are not negligible in concentrated and semidilute ionic systems. Next we discuss several classes of polymer electrolytes (gels, block copolymers, and composites) that are already employed or have good potential to be employed in current battery technologies. At the end we discuss perspectives for the design of dry single-ion conducting polymer electrolytes with required room temperature conductivity.
Phases of matter are usually identified through spontaneous symmetry breaking, especially regarding unconventional superconductivity and the interactions from which it originates. In that context, ...the superconducting state of the quasi-two-dimensional and strongly correlated perovskite Sr2RuO4 is considered to be the only solid-state analogue to the superfluid 3He-A phase, with an odd-parity order parameter that is unidirectional in spin space for all electron momenta and breaks time-reversal symmetry. This characterization was recently called into question by a search for an expected 'split' transition in a Sr2RuO4 crystal under in-plane uniaxial pressure, which failed to find any such evidence; instead, a dramatic rise and a peak in a single-transition temperature were observed. Here we use nuclear magnetic resonance (NMR) spectroscopy of oxygen-17, which is directly sensitive to the order parameter via hyperfine coupling to the electronic spin degrees of freedom, to probe the nature of superconductivity in Sr2RuO4 and its evolution under strain. A reduction of the Knight shift is observed for all strain values and at temperatures below the critical temperature, consistent with a drop in spin polarization in the superconducting state. In unstrained samples, our results contradict a body of previous NMR work reporting no change in the Knight shift and the most prevalent theoretical interpretation of the order parameter as a chiral p-wave state. Sr2RuO4 is an extremely clean layered perovskite and its superconductivity emerges from a strongly correlated Fermi liquid, and our work imposes tight constraints on the order parameter symmetry of this archetypal system.
Furthermore, absent late positive event-related potential on electroencephalography (EEG) during processing of emotional face expressions in patients with cerebellar stroke indicated the network for ...interpretation of emotional information may be altered after cerebellar damage (Adamaszek et al., 2015). Cerebellar Activation and Connectivity Patterns in Social Cognition A meta-analysis of over 350 functional magnetic resonance imaging (fMRI) studies reported consistent cerebellar activations during different tasks on social cognition, including observation of human motion, mentalizing about intentions in social interactions, inference on personality traits and abstraction (Van Overwalle et al., 2014). Besides its unrivaled potential for fundamental discovery, the causality afforded by cellular neuroscience is very helpful to evaluate hypotheses. In Long-Evans rats, delta band coherence was found between deep cerebellar nuclei and contralateral medial frontal cortex, and muscimol-mediated inactivation of their deep cerebellar nuclei neurons altered interval timing performance.
Sr2RuO4 has stood as the leading candidate for a spin-triplet superconductor for 26 years1. However, recent NMR experiments have cast doubt on this candidacy2,3 and it is difficult to find a theory ...of superconductivity that is consistent with all experiments. The order parameter symmetry for this material therefore remains an open question. Symmetry-based experiments are needed that can rule out broad classes of possible superconducting order parameters. Here, we use resonant ultrasound spectroscopy to measure the entire symmetry-resolved elastic tensor of Sr2RuO4 through the superconducting transition. We observe a thermodynamic discontinuity in the shear elastic modulus c66, which implies that the superconducting order parameter has two components. A two-component p-wave order parameter, such as px + ipy, naturally satisfies this requirement. As this order parameter appears to have been precluded by recent NMR experiments, we suggest that two other two-component order parameters, namely {dxz,dyz} and {dx2−y2,gxy(x2−y2)}, are now the prime candidates for the order parameter of Sr2RuO4.Ultrasound measurements show that the superconducting order parameter in strontium ruthenate must have two components.
The cerebellum is believed to play an essential role in a variety of motor and cognitive functions through reciprocal interaction with the cerebral cortex. Recent findings suggest that cerebellar ...involvement in the network specialized for visual body motion processing may be mediated through interaction with the right superior temporal sulcus (STS). Yet, the underlying pattern of structural connectivity between the STS and the cerebellum remains unidentified. In the present work, diffusion tensor imaging analysis on seeds derived from functional magnetic resonance imaging during a task on point-light biological motion perception uncovers a structural pathway between the right posterior STS and the left cerebellar lobule Crus I. The findings suggest existence of a structural loop underpinning bidirectional communication between the STS and cerebellum. This connection might also be of potential value for other visual social abilities.
Combining broadband impedance spectroscopy, differential scanning calorimetry, and nuclear magnetic resonance we analyzed charge and mass transport in two polymerized ionic liquids and one of their ...monomeric precursors. In order to establish a general procedure for extracting single-particle diffusivity from their conductivity spectra, we critically assessed several approaches previously employed to describe the onset of diffusive charge dynamics and of the electrode polarization in ion conducting materials. Based on the analysis of the permittivity spectra, we demonstrate that the conductivity relaxation process provides information on ion diffusion and the magnitude of cross-correlation effects between ionic motions. A new approach is introduced which is able to estimate ionic diffusivities from the characteristic times of conductivity relaxation and ion concentration without any adjustable parameters. This opens the venue for a deeper understanding of charge transport in concentrated and diluted electrolyte solutions.
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