Pairs of sentences, phrases, or other text pieces can hold semantic relations such as paraphrasing, textual entailment, contradiction, specificity, and semantic similarity. These relations are usually studied in isolation and no dataset exists where they can be compared empirically. Here we present a corpus annotated with these relations and the analysis of these results. The corpus contains 520 sentence pairs, annotated with these relations. We measure the annotation reliability of each individual relation and we examine their interactions and correlations. Among the unexpected results revealed by our analysis is that the traditionally considered direct relationship between paraphrasing and bi-directional entailment does not hold in our data

Information spreading has been studied for decades, but the underlying mechanism why the information can be accepted by a large number of people overnight is still under debate, especially in the aspects of two-channel effects for information transmission and theoretical analysis. In this study, based on a susceptible-accepted-recovered (SAR) model, we examine the effects of two channels represented by a two-layered network, in which one channel is the intra-links within the same layer and the other is inter-links between layers. Different with the case of one single channel on a one-layered network, in the case of two channels, the spreading can be speeded up by the increase in the coupling strength, i.e., average node degree and transmission probability between the two layers. Strikingly, even if the parameter (social reinforcement) is small, the strongly coupling strength can induce explosive transition in the information spreading process. Additionally, a big gap closed to the critical point for the explosive transition was found in the phase space of theoretical analysis, which indicates the emergency of a global large-scope outbreak. These findings may be of significance on the understanding and controlling explosive information spreading in modern society.

Archaeological excavations provide us with important clues about the past. Excavated artefacts represent an important connection to civilisations that no longer exist and help us understand some of their customs, traditions and common practices. With the help of academics and practitioners from various disciplines, the results of archaeological excavations can be analysed and a body of knowledge about the corresponding society can be created and shared with members of the general public. Museums have traditionally served the purpose of communicating this knowledge and backing it up with the help of the excavated artefacts. Many museum visitors, however, find it difficult to develop a coherent understanding of the corresponding society only based on the artefacts and annotations shown in museums. Effective modern techniques that have high potential in helping museum visitors with better understanding of the past are 3D reconstruction and virtual reality. 3D reconstruction offers a cost-effective way of recreating historical settlements in a computer-generated virtual environment, while virtual reality helps with immersing people into such environments and reaching a high degree of realism. With the help of these technologies, it becomes possible to relive history, imagine yourself being a part of the reconstructed society and learn about its culture firsthand. The combination of 3D reconstruction and virtual reality represents a very powerful learning tool; however, this tool has been rarely used in a museum setting and its correct use has not been properly investigated. In this paper, we present a study into using virtual reality in itinerant archaeological exhibitions. We discuss the lessons we have learned from developing an interactive virtual reality simulation of the Neolithic settlement of La Draga. These lessons feature our analysis of qualitative and quantitative feedback of museum visitors, as well as what we have learned from analysing their navigation and interaction patterns.

Solid polymer electrolytes (SPEs) have the potential to enhance the safety and energy density of lithium batteries. However, poor interfacial contact between the lithium metal anode and SPE leads to high interfacial resistance and low specific capacity of the battery. In this work, we present a novel strategy to improve this solid–solid interface problem and maintain good interfacial contact during battery cycling by introducing an adaptive buffer layer (ABL) between the Li metal anode and SPE. The ABL consists of low molecular-weight polypropylene carbonate , poly(ethylene oxide) (PEO), and lithium salt. Rheological experiments indicate that ABL is viscoelastic and that it flows with a higher viscosity compared to PEO-only SPE. ABL also has higher ionic conductivity than PEO-only SPE. In the presence of ABL, the interface resistance of the Li/ABL/SPE/LiFePO4 battery only increased 20% after 150 cycles, whereas that of the battery without ABL increased by 117%. In addition, because ABL makes a good solid–solid interface contact between the Li metal anode and SPE, the battery with ABL delivered an initial discharge specific capacity of >110 mA·h/g, which is nearly twice that of the battery without ABL, which is 60 mA·h/g. Moreover, ABL is able to maintain electrode–electrolyte interfacial contact during battery cycling, which stabilizes the battery Coulombic efficiency.

Synchronization, the temporal coordination of coupled oscillators, allows fireflies to flash in unison, neurons to fire collectively, and human crowds to fall in step on the London millenium bridge. Here, we interpret active (or self-propelled) chiral microswimmers with a distribution of intrinsic frequencies as motile oscillators and show that they can synchronize over very large distances, even for local coupling in two dimensions (2D). This opposes canonical nonactive oscillators on static or time-dependent networks, leading to synchronized domains only. A consequence of this activity-induced synchronization is the emergence of a “mutual flocking phase,” where particles of opposite chirality cooperate to form superimposed flocks moving at a relative angle to each other, providing a chiral active matter analogue to the celebrated Toner-Tu phase. The underlying mechanism employs a positive feedback loop involving the two-way coupling between oscillators' phase and self-propulsion and could be exploited as a design principle for synthetic active materials and chiral self-sorting techniques.

Capillary‐based microfluidics is a great technique to produce monodisperse and complex emulsions and particulate suspensions. In this review, the current understanding of drop and jet formation in capillary‐based microfluidic devices for two primary flow configurations, coflow and flow‐focusing is summarized. The experimental and theoretical description of fluid instabilities is discussed and conditions for controlled drop breakup in different modes of drop generation are provided. Current challenges in drop breakup with low interfacial tension systems and recent progress in overcoming drop size limitations using electro‐coflow are addressed. In each scenario, the physical mechanisms for drop breakup are revisited, and simple scaling arguments proposed in the literature are introduced.

We present a theoretical framework to understand the collective dynamics of an ensemble of electrophoretically driven colloidal particles that are forced to assemble around a single topological defect in a nematic liquid crystal by an alternating current electric field. Our generic model combines phoretic propulsion with electrostatic interactions and liquid-crystal-mediated hydrodynamics, which are effectively cast into a long-range interparticle repulsion, while nematic elasticity plays a subdominant role. Simulations based on this model fully capture the collective organization process observed in the experiments and other striking effects as the emergence of conformal ordering and a nearly frequency-independent repulsive interaction above 10Hz. Our results demonstrate the importance of hydrodynamic interactions on the assembly of driven microscale matter in anisotropic media.

Many liquid crystalline systems display spontaneous breaking of achiral symmetry, as achiral molecules aggregate into large chiral domains. In confined cylinders with homeotropic boundary conditions, chromonic liquid crystals – which have a twist elastic modulus which is at least an order of magnitude less than their splay and bend counter parts – adopt a twisted escaped radial texture (TER) to minimize their free energy, whilst 5CB – which has all three elastic constants roughly comparable – does not. In a recent series of experiments, we have shown that 5CB confined to tori and bent cylindrical capillaries with homeotropic boundary conditions also adopts a TER structure resulting from the curved nature of the confining boundaries [P. W. Ellis et al., Phys. Rev. Lett., 2018, 247803]. We shall call this microscopic twist, as the twisted director organization not only depends on the confinement geometry but also on the values of elastic moduli. Additionally, we demonstrate theoretically that the curved geometry of the boundary induces a twist in the escaped radial (ER) texture. Moving the escaped core of the structure towards the center of the torus not only lowers the splay and bend energies, but lowers the energetic cost of this distinct source for twist that we shall call geometric twist. As the torus becomes more curved, the ideal location for the escaped core approaches the inner radius of the torus.

We apply an electric field to a moderately conducting liquid surrounded by another co-flowing liquid, all inside a glass-based microfluidic device, and study and classify the resulting emission modes. The viscosity and flow rate of the co-flowing liquid affect the number of modes observed in classical electrospray as well as their geometrical characteristics. In particular, we observe a two-dimensional whipping mode not described before. We also provide a qualitative description of some of the modes, including dripping, electrodripping, microdripping, the cone-jet mode, and both the two- and three-dimensional whipping modes.

We experimentally analyze the intermittent nature of granular silo flow when the discharge is controlled by an extracting belt at the bottom. We discover the existence of four different scenarios. For low extraction rates, the system is characterized by an on-off intermittency. When the extraction rate is increased the structure functions of the grains velocity increments, calculated for different lag times, reveal the emergence of multifractal intermittency. Finally, for very high extraction rates that approach the purely gravitational discharge, we observe that the dynamics become dependent on the outlet size. For large orifices the behavior is monofractal, whereas for small ones, the fluctuations of the velocity increments deviate from Gaussianity even for very large time lags.

Phagocytes protect the organism by ingesting harmful foreign particles and cells. We use mesoscale computer simulations to design a phagocyte-inspired active microcapsule that is capable of selectively capturing nanoparticles dispersed in solvent. Our fully synthetic microdevice is actuated by a temperature-sensitive microgel enclosed inside a perforated spherical shell. The shell pores are decorated with a copolymer brush that regulates the transport of solutes into the capsule interior. When exposed to an external stimulus, the microgel swells, expanding through the shell pores to make contact with the nanoparticle-rich solution surrounding the capsule. Upon removal of the external stimulus, the gel retracts back into the shell, bringing along with it captured nanoparticles. We probe how periodic application of the stimulus combined with nanoparticle-microgel adhesion enable selectivity and enhance capturing efficiency of our nature-inspired microdevice.

Simulated optical polarizing microscopy (OPM) textures can be used to help compare a director ansatz with an associated experimental OPM texture. Here, we present a pedagogical treatmement of a simulation formalism based on the method of Jones matrices. We focus on toroidal geometries as an example and perform computer simulations of the nematic textures seen between crossed-polarizers. For tangentially-anchored nematic tori, we compare qualitative and quantitative features between experimental and simulated OPM textures and discuss the influence of twist in the director field. In addition, we quantify the effect of averaging over multiple wavelengths, the effect of voxel size, how refraction affects the comparison between experimental and simulated OPM textures, and the effect of deviations from the toroidal shape. For homeotropically-anchored nematic tori, we adapt the classic escaped-radial director field found in homeotropically-anchored capillaries to a toroidal geometry to produce simulated OPM textures. Lastly, we show that the same signatures of twist in the tangentially-anchored nematic toroids persist in the homeotropically-anchored nematic toroids.

Concentrated poly(N-isopropylacrylamide) (pNIPAM) microgel suspensions at a fixed temperature below the deswelling transition of pNIPAM exhibit spontaneous particle deswelling. The microgels deswell before they are in direct contact and in polydisperse suspensions this deswelling is most pronounced for the largest microgel particles; as a consequence, the polydispersity of the suspension is reduced. Recently, we presented a model for this spontaneous deswelling that is based on the presence of counterions originating from charged groups on the surface of the pNIPAM microgels [A. Scotti et al., Proc. Natl. Acad. Sci. USA 113, 5576 (2016)]. Here we present numerical Poisson-Boltzmann calculations of the electrostatic potential and osmotic pressure inside and outside a pNIPAM microgel that could trigger the observed deswelling at high particle concentrations.

We present a pedagogical review of the swelling thermodynamics and phase transitions of polymer gels. In particular, we discuss how features of the volume phase transition of the gel's osmotic equilibrium are analogous to other transitions described by mean-field models of binary mixtures, and the failure of this analogy at the critical point due to shear rigidity. We then consider the phase transition at fixed volume, a relatively unexplored paradigm for polymer gels that results in a phase-separated equilibrium consisting of coexisting solvent-rich and solvent-poor regions of gel. Again, the gel's shear rigidity is found to have a profound effect on the phase transition, here resulting in macroscopic shape change at constant volume of the sample, exemplified by the tunable buckling of toroidal samples of polymer gel. By drawing analogies with extreme mechanics, where large shape changes are achieved via mechanical instabilities, we formulate the notion of extreme thermodynamics, where large shape changes are achieved via thermodynamic instabilities, i.e. phase transitions.

The kinesin-3 motor KIF1A is involved in long-ranged axonal transport in neurons. To ensure vesicular delivery, motors need to navigate the microtubule lattice and overcome possible roadblocks along the way. The single-headed form of KIF1A is a highly diffusive motor that has been shown to be a prototype of a Brownian motor by virtue of a weakly bound diffusive state to the microtubule. Recently, groups of single-headed KIF1A motors were found to be able to sidestep along the microtubule lattice, creating left-handed helical membrane tubes when pulling on giant unilamellar vesicles in vitro. A possible hypothesis is that the diffusive state enables the motor to explore the microtubule lattice and switch protofilaments, leading to a left-handed helical motion. Here, we study the longitudinal rotation of microtubules driven by single-headed KIF1A motors using fluorescence-interference contrast microscopy. We find an average rotational pitch of ≃1.5≃1.5 μm, which is remarkably robust to changes in the gliding velocity, ATP concentration, microtubule length, and motor density. Our experimental results are compared to stochastic simulations of Brownian motors moving on a two-dimensional continuum ratchet potential, which quantitatively agree with the fluorescence-interference contrast experiments. We find that single-headed KIF1A sidestepping can be explained as a consequence of the intrinsic handedness and polarity of the microtubule lattice in combination with the diffusive mechanochemical cycle of the motor.

During the spreading of epithelial tissues, the advancing tissue front often develops fingerlike protrusions. Their resemblance to traditional viscous fingering patterns in driven fluids suggests that epithelial fingers could arise from an interfacial instability. However, the existence and physical mechanism of such a putative instability remain unclear. Here, based on an active polar fluid model for epithelial spreading, we analytically predict a generic instability of the tissue front. On the one hand, active cellular traction forces impose a velocity gradient that leads to an accelerated front, which is, thus, unstable to long-wavelength perturbations. On the other hand, contractile intercellular stresses typically dominate over surface tension in stabilizing short-wavelength perturbations. Finally, the finite range of hydrodynamic interactions in the tissue selects a wavelength for the fingering pattern, which is, thus, given by the smallest between the tissue size and the hydrodynamic screening length. Overall, we show that spreading epithelia experience an active fingering instability based on a simple kinematic mechanism. Moreover, our results underscore the crucial role of long-range hydrodynamic interactions in the dynamics of tissue morphology.

To determine the measurement properties of the Spanish version of the COMFORT Behavior Scale developed by van Dijk et al. (2000) in pediatric critical care patients.

Age-related changes in the brain connectivity of healthy older adults have been widely studied in recent years, with some differences in the obtained results. Most of these studies showed decreases in general functional connectivity, but they also found increases in some particular regions and areas. Frequently, these studies compared young individuals with older subjects, but few studies compared different age groups only in older populations. The purpose of this study is to analyze whole-brain functional connectivity in healthy older adult groups and its network characteristics through functional segregation. A total of 114 individuals, 48 to 89 years old, were scanned using resting-state functional magnetic resonance imaging in a resting state paradigm and were divided into six different age groups (< 60, 60–64, 65–69, 70–74, 75–79, ≥ 80 years old). A partial correlation analysis, a pooled correlation analysis and a study of 3-cycle regions with prominent connectivity were conducted. Our results showed progressive diminution in the functional connectivity among different age groups and this was particularly pronounced between 75 and 79 years old. The oldest group (≥ 80 years old) showed a slight increase in functional connectivity compared to the other groups. This occurred possibly because of compensatory mechanism in brain functioning. This study provides information on the brain functional characteristics of every age group, with more specific information on the functional progressive decline, and supplies methodological tools to study functional connectivity characteristics. Approval for the study was obtained from the ethics committee of the Comisión de Bioética de la Universidad de Barcelona (approval No. PSI2012-38257) on June 5, 2012, and from the ethics committee of the Barcelona’s Hospital Clínic (approval No. 2009-5306 and 2011-6604) on October 22, 2009 and April 7, 2011 respectively.

We study the flow properties of red blood cells in confined channels, when the channel width is comparable to the cell size. We focus on the case of intermediate concentrations when hydrodynamic interactions between cells play a dominant role. This regime is different to the case of low concentration in which the cells behave as hydrodynamically isolated. In this last case, the dynamic behavior is entirely controlled by the interplay between the interaction with the wall and the elastic response of the cell membrane. Our results highlight the different fluid properties when collective flow is present. The cells acquire a characteristic slipper shape, and parachute shapes are only observed at very large capillary numbers. We have characterized the spatial ordering and the layering by means of a pairwise correlation function. Focusing effects are observed at the core of the channel instead of at the lateral position typical of the single-train case. These results indicate that at these intermediate concentrations we observed at the microscale the first steps of the well-known macroscopic Fahraeus-Lindqvist effect. The rheological properties of the suspension are studied by means of the effective viscosity, with an expected shear-thinning behavior. Two main differences are obtained with respect to the single-train case. First, a large magnitude of the viscosity is obtained indicating a high resistance to flow. Secondly, the shear-thinning behavior is obtained at larger values of the capillary number respect to the single-train case. These results suggest that the phenomena of ordering in space and orientation occur at higher values of the capillary number.

Patient-specific induced pluripotent stem cells (iPSCs) are a powerful tool to investigate the molecular mechanisms underlying Parkinson’s disease (PD), and might provide novel platforms for systematic drug screening. Several strategies have been developed to generate iPSC-derived tyrosine hydroxylase (TH)-positive dopaminergic neurons (DAn), the clinically relevant cell type in PD; however, they often result in mixed neuronal cultures containing only a small proportion of TH-positive DAn. To overcome this limitation, we used CRISPR/Cas9-based editing to generate a human iPSC line expressing a fluorescent protein (mOrange) knocked-in at the last exon of the TH locus. After differentiation of the TH-mOrange reporter iPSC line, we confirmed that mOrange expression faithfully mimicked endogenous TH expression in iPSC-derived DAn. We also employed calcium imaging techniques to determine the intrinsic functional differences between dopaminergic and non-dopaminergic ventral midbrain neurons. Crucially, the brightness of mOrange allowed direct visualization of TH-expressing cells in heterogeneous cultures, and enabled us to isolate live mOrange-positive cells through fluorescence-activated cell sorting, for further differentiation. This technique, coupled to refined imaging and data processing tools, could advance the investigation of PD pathogenesis and might offer a platform to test potential new therapeutics for PD and other neurodegenerative diseases.

We study the structural and dynamical consequences of damage in spatial neuronal networks. Inspired by real in vitro networks, we construct directed networks embedded in a two-dimensional space and follow biological rules for designing the wiring of the system. As a result, synthetic cultures display strong metric correlations similar to those observed in real experiments. In its turn, neuronal dynamics is incorporated through the Izhikevich model adopting the parameters derived from observation in real cultures. We consider two scenarios for damage, targeted attacks on those neurons with the highest out-degree and random failures. By analyzing the evolution of both the giant connected component and the dynamical patterns of the neurons as nodes are removed, we observe that network activity halts for a removal of 50% of the nodes in targeted attacks, much lower than the 70% node removal required in the case of random failures. Notably, the decrease of neuronal activity is not gradual. Both damage scenarios portray “boosts” of activity just before full silencing that are not present in equivalent random (Erdös–Rényi) graphs. These boosts correspond to small, spatially compact subnetworks that are able to maintain high levels of activity. Since these subnetworks are absent in the equivalent random graphs, we hypothesize that metric correlations facilitate the existence of local circuits sufficiently integrated to maintain activity, shaping an intrinsic mechanism for resilience.

 Background: Mild cognitive impairment (MCI) is a diagnostic label in which stability is typically low. The aim of this study was to examine temporal changes in the diagnosis of MCI subtypes by using an overlapping-time strategy; (2) Methods: The study included 435 participants aged over 50 years with subjective cognitive complaints and who completed at least one follow-up evaluation. The probability of transition was estimated using Bayesian odds ratios; (3) Results: Within the different time intervals, the controls with subjective cognitive complaints represented the largest proportion of participants, followed by sda-MCI at baseline and in the first five intervals of the follow-up, but not in the last eight intervals. The odds ratios indicated higher odds of conversion to dementia in sda-MCI and mda-MCI groups relative to na-MCI (e.g., interval 9–15 months—sda-MCI OR = 9 and mda-MCI OR = 3.36; interval 27–33—sda-MCI OR = 16 and mda-MCI = 5.06; interval 42–48—sda-MCI OR = 8.16 and mda-MCI = 3.45; interval 45–51—sda-MCI OR = 3.31 and mda-MCI = 1); (4) Conclusions: Notable patterns of instability consistent with the current literature were observed. The limitations of a prospective approach in the study of MCI transitions are discussed

A cross-national comparison between Italy and Spain was conducted on probabilistic reasoning performance presented in verbal-numerical and graphical-pictorial formats. This study investigated the similarities and differences in Psychology undergraduates in these two countries (Italy n=290; Spain n=130) and attempted to identify aspects that might enhance the probability of a student belonging to one country. The findings underscored that Spanish students had higher levels of visuospatial abilities, more positive attitudes toward statistics, lower statistical anxiety, and higher confidence in the correctness of their responses. Additionally, they gave a higher number of correct responses to problems presented in a verbal-numerical format. These data suggest interesting insights and highlight the interactions among multiple layers of variables at the collective, contextual, and individual levels.

Archaeology and Collectionism: Gabriel de Molina and the beginning of the excavations at Empúries (Abastract) The year 2008 marked the centenary of the beginning of the archaeological excavations at the ancient Greco-Roman city of Empúries. Without wishing to deny the cultural and symbolic relevance of this anniversary, in the following pages we will explain that, in fact, the first interventions in this site are much older and, among other characters today almost forgotten, the civil servant Gabriel de Molina Ramos played an important role in them. Reason why we think of interest to investigate who he was and for what reason he was attracted to archaeology. This research is based on unpublished documents found in different Catalan and statewide archives. Keywords: Empúries, archaeology historigraphy, collectionism, liberalism, 19th Century

This paper applies a two-mode social network analysis approach to identify the brokers in knowledge networks resulting from interactions taking place at specialized seminars and courses organized in a tourism destination. Empirical findings show that technology and innovation centers can be the leading hub of ‘administered knowledge networks’ – understood as efficient knowledge governance arrangements – in which a wide variety of actors, including universities, private-sector associations, public organizations, and firms play complementary roles depending on the nature of the interactions (formal transfer versus informal exchange flows). These structures are found to be fundamental for the functioning of localized systems of learning.