Phasic changes in eye’s pupil diameter have been repeatedly observed during cognitive, emotional and behavioral activity in mammals. Although pupil diameter is known to be associated with noradrenergic firing in the pontine Locus Coeruleus (LC), thus far the causal chain coupling spontaneous pupil dynamics to specific cortical brain networks remains unknown. In the present study, we acquired steady-state blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) data combined with eye-tracking pupillometry from fifteen healthy subjects that were trained to maintain a constant attentional load. Regression analysis revealed widespread visual and sensorimotor BOLD-fMRI deactivations correlated with pupil diameter. Furthermore, we found BOLD-fMRI activations correlated with pupil diameter change rate within a set of brain regions known to be implicated in selective attention, salience, error-detection and decision-making. These regions included LC, thalamus, posterior cingulate cortex (PCC), dorsal anterior cingulate and paracingulate cortex (dACC/PaCC), orbitofrontal cortex (OFC), and right anterior insular cortex (rAIC). Granger-causality analysis performed on these regions yielded a complex pattern of interdependence, wherein LC and pupil dynamics were far apart in the network and separated by several cortical stages. Functional connectivity (FC) analysis revealed the ubiquitous presence of the superior frontal gyrus (SFG) in the networks identified by the brain regions correlated to the pupil diameter change rate. No significant correlations were observed between pupil dynamics, regional activation and behavioral performance. Based on the involved brain regions, we speculate that pupil dynamics reflects brain processing implicated in changes between self- and environment-directed awareness.

The effect of Ru substitution on the local structure of layered SmFe1−xRuxAsO0.85F0.15 superconductor has been studied by As K-and Sm L3 -edges x-ray-absorption spectroscopy. The extended x-ray-absorption fine-structure measurements reveal distinct Fe-As and Ru-As bondlengths in the Ru substituted samples with the latter being ∼0.03 Å longer. Local disorder induced by the Ru substitution is mainly confined to the FeAs layer while the SmO spacer layer sustains a relative order, consistent with the x-ray-absorption near-edge structure spectra. The results suggest that, in addition to the order/disorder in the active active iron-arsenide layer, its coupling to the rareearth−oxygen spacer layer needs to be considered for describing the electronic properties of these layered superconductors.

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One of the more intriguing aspects of carbohydrate chemistry is that despite having very similar molecular structures, sugars have very different properties. For instance, there is a sensible difference in sweet taste between glucose and trehalose, even though trehalose is a disaccharide that comprised two glucose units, suggesting a different ability of these two carbohydrates to bind to sweet receptors. Here we have looked at the hydration of specific sites and at the three-dimensional configuration of water molecules around three carbohydrates (glucose, cellobiose, and trehalose), combining neutron diffraction data with computer modelling. Results indicate that identical chemical groups can have radically different hydration patterns depending on their location on a given molecule. These differences can be linked with the specific activity of glucose, cellobiose, and trehalose as a sweet substance, as building block of cellulose fiber, and as a bioprotective agent, respectively. This article is part of a Special Issue entitled "Recent Advances in Bionanomaterials" Guest Editors: Dr. Marie-Louise Saboungi and Dr. Samuel D. Bader.

Fossils sometimes show unusual morphological features absent in living organisms, making it difficult to reconstruct both their affinity and their function. We describe here a new lacewing larva, Ankyloleon caudatus gen. et sp.n. (Neuroptera) from the Cretaceous amber of Myanmar, characterized by an abdomen unique among insects, with ‘tail‐like’ terminal segments bearing a ventral pair of vesicles. Phase‐contrast X‐ray microtomography reveals that these structures were dense and equipped with a median duct, suggesting that they were likely pygopods used for locomotion, holding the position through adhesive secretions. Our phylogenetic analyses, combining genomic and morphological data from both living and fossil lacewings, proved critical to placing Ankyloleon gen.n. on the lacewing tree of life as an early representative of the antlion clade, Myrmeleontiformia. These results corroborate the view that derived myrmeleontiform lacewings ‘experimented’ with unusual combinations of features and specializations during their evolutionary history, some of which are now lost. Zoobank registration: urn:lsid:zoobank.org:pub:0C0AC565‐1AC9‐42CC‐831D‐EDA38BA36F64

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Local structure of SmFe1−xRuxAsO0.85F0.15 (x = 0.0, 0.05, 0.25 and 0.5) superconductors has been investigated by temperature dependent As K-edge extended x-ray absorption fine structure.The effect of Ru substitution remains confined to the iron-arsenide layer but neither the static disorder nor the Fe-As bond strength suffers any change for x ≤ 0.25. With further Ru substitution the static disorder increases while the Fe-As bond strength remains unchanged. Also, the Ru-As distance (∼2.42 Å), different from the Fe-As distance (∼2.39 Å), does not show any change in its force constant with the Ru substitution. These observations suggest that the SmFe1−xRuxAsO0.85F0.15 system breaks down to coexisting local electronic phases on isoelectric substitution in the active FeAs layer.