This paper provides an overview of a planned experiment to evaluate the latest iteration of ADELE, an artificial conversational agent to aid in the care of the elderly. It is being evaluated against an earlier iteration of itself and against the leading systems from the 2018 ConvAI2 Challenge at NeurIPS (formally NIPS) to measure its progress on producing improved natural social dialogue.
The full text of this article will not be available in ULIR until the embargo expires on the 13/02/2021 Caffeine and maleic acid can form various cocrystal forms, which is a potential route to avoiding hydration issues of caffeine. This particular system was intensively studied as it not only shows cocrystal polymorphism but also stoichiometrically diverse cocrystals with a 1:1 maleic acid: caffeine (MC) and a 1:2 maleic acid:caffeine (MC2) form already identified. A cocrystallization process for MC was already developed. However, a process leading to pure MC2 remained a challenge, as the stability zone of the MC2 suspension is very narrow in most solvents. In this paper, we propose an alternative crystallization pathway toward this crystal form, passing through a stable solvate. Indeed, we identified a novel cocrystal solvate of MC2 (MC2·MeCN) in acetonitrile at 9 °C. This cocrystal solvate is characterized by a large stability zone in the ternary phase diagram, and consequently, a crystallization process leading to this form can easily be devised. Upon filtration, and exposure to ambient atmosphere, MC2·MeCN is quickly desolvated leading to the pure MC2 cocrystal phase. In this contribution, we therefore show that cocrystal phases, which are seemingly strenuous to crystallize from solution, can be accessed by thinking out-of-the-box and using the properties of unexpected alternative phases.
The full text of this article will not be available in ULIR until the embargo expires on the 16/03/2021
The full text of this article will not be available in ULIR until the embargo expires on the 11/02/2021 Summary Ferroelectric materials, and more specifically ferroelectric domain walls (DWs) have become an area of intense research in recent years. Novel physical phenomena have been discovered at these nanoscale topological polarization discontinuities by mapping out the polarization in each atomic unit cell around the DW in a scanning transmission electron microscope (STEM). However, identifying these features requires an understanding of the polarization in the overall domain structure of the TEM sample, which is often a time‐consuming process. Here, a fast method of polarization mapping in the TEM is presented, which can be applied to a range of ferroelectric materials. Due to the coupling of polarization to spontaneous strain, we can isolate different strain states and demonstrate the fast mapping of the domain structure in ferroelectric lead titanate (PTO). The method only requires a high‐resolution TEM or STEM image and is less sensitive to zone axis or local strain effects, which may affect other techniques. Thus, it is easily applicable to in‐situ experiments. The complimentary benefits of Fourier masking with more advanced mapping strategies and its application to other materials are discussed. These results imply that Fourier masked polarization mapping will be a useful tool for electron microscopists in streamlining their analysis of ferroelectric TEM samples. Lay Description This paper addresses a problem that often occurs when looking at a ferroelectric material in the Transmission Electron Microscope (TEM). Ferroelectric samples are interesting because they form tiny areas inside themselves with arrow of charge in each one. The thinner the sample, the smaller these regions, called “domains” become. These arrows of charge point in different directions in each domain of the sample. The boundary where these domains meet have interesting properties to study in a TEM but it's important to figure out which way the arrows point in the domains around the boundary. What causes the arrows in the different domains is tiny shifts of different atoms in unit cell away from their neutral position, usually because they're being squeezed by pressure from the domains nearby. The problem is that these tiny atoms moving are difficult to measure and see where the charged arrow is pointing, often it's hard to know how many different domains are even in the sample and where they begin. This paper discusses a method called “Fourier masking” to quickly see what's going on in the overall TEM sample, where the domains are and roughly where the arrows point. It does this by looking at the spacings of the atoms from a magnification where you can just about see the lines of atoms. In lead titanate the unit cell is a rectangle and the arrow always points in line with the long side of the rectangle. The Fourier masking lets you see which direction the long side of the rectangular unit cell is pointing in different parts of your TEM image. The big advantage is that it takes about two minutes to do and uses software that almost every TEM already has. That lets the TEM user quickly know where the domains are in their TEM samples and roughly which way the arrows of charge are pointing. Then they can choose the most interesting features focus on for higher resolution analysis.
Neurodegeneration involves abnormal aggregation of intrinsically disordered amyloidogenic peptides (IDPs), usually mediated by hydrophobic protein-protein interactions. There is mounting evidence that formation of α-helical intermediates is an early event during self-assembly of amyloid-β42 (Aβ42) and α-synuclein (αS) IDPs in Alzheimer’s and Parkinson’s disease pathogenesis, respectively. However, the driving force behind on-pathway molecular assembly of partially folded helical monomers into helical oligomers assembly remains unknown. Here, we employ extensive molecular dynamics simulations to sample the helical conformational sub-spaces of monomeric peptides of both Aβ42 and αS. Our computed free energies, population shifts, and dynamic cross-correlation network analyses reveal a common feature of long-range intra-peptide modulation of partial helical folds of the amyloidogenic central hydrophobic domains via concerted coupling with their charged terminal tails (N-terminus of Aβ42 and C-terminus of αS). The absence of such inter-domain fluctuations in both fully helical and completely unfolded (disordered) states suggests that long-range coupling regulates the dynamicity of partially folded helices, in both Aβ42 and αS peptides. The inter-domain coupling suggests a form of intra-molecular allosteric regulation of the aggregation trigger in partially folded helical monomers. This approach could be applied to study the broad range of amyloidogenic peptides, which could provide a new path to curbing pathogenic aggregation of partially folded conformers into oligomers, by inhibition of sites far from the hydrophobic core.
A domain wall-enabled memristor is created, in thin film lithium niobate capacitors, which shows up to twelve orders of magnitude variation in resistance. Such dramatic changes are caused by the injection of strongly inclined conducting ferroelectric domain walls, which provide conduits for current flow between electrodes. Varying the magnitude of the applied electric-field pulse, used to induce switching, alters the extent to which polarization reversal occurs; this systematically changes the density of the injected conducting domain walls in the ferroelectric layer and hence the resistivity of the capacitor structure as a whole. Hundreds of distinct conductance states can be produced, with current maxima achieved around the coercive voltage, where domain wall density is greatest, and minima associated with the almost fully switched ferroelectric (few domain walls). Significantly, this “domain wall memristor” demonstrates a plasticity effect: when a succession of voltage pulses of constant magnitude is applied, the resistance changes. Resistance plasticity opens the way for the domain wall memristor to be considered for artificial synapse applications in neuromorphic circuits
Serious games are becoming increasingly popular due to their association with increased learning outcomes when compared to traditional self‐regulated learning activities. However, the majority of research examining the outcomes of serious games has focused almost exclusively on learning outcomes. This has resulted in a lack of research examining why these types of games result in increased positive outcomes, such as engagement or performance. This study seeks to address this gap in existing research by examining the relationship between game difficulty and participants’ engagement, performance and self‐efficacy in a Pacman style maze navigation game. This required the use of hidden difficulty variations which participants were randomly assigned. Participants engaged with the game over a 5‐days practice period. Results from this study suggest that difficulty plays a considerable role in influencing participants’ self‐efficacy for the task. Self‐efficacy has been consistently linked to positive outcomes such as increased engagement and performance. This highlights the importance of difficulty as a game design factor as well as providing an insight into the manner in which serious games could be further refined in order to increase user’s self‐efficacy and associated positive outcomes. Implications for future serious games and self‐efficacy research are discussed.
Agricultural trade relations between the EU and China are promising given the background of a rising trend of global economic and trade development. This study is conducted within the framework of international trade theories, global economic and trade development especially in terms of agricultural trade, as well as agricultural and trade policy of both the EU and China. Within the trade theoretical framework and the policy framework, this study adopts both quantitative and qualitative research methods to analyse EU-China agricultural trade relations from the perspectives of comparative advantage, trade complementarity, trade potential, and policy recommendations. Specifically, Balassa’s Revealed Comparative Advantage Index (BRCA), a Normalized Comparative Advantage Index (NRCA) as well as a Trade Complementarity Index (TCI) are employed to quantify the degree of comparative advantage and trade complementarity for the EU and China in relation to defined agricultural products. Based on NRCA- and TCI-based preliminary results, an OLS regression analysis, a Markov one-step transition probability, and a mobility index are also applied in order to analyse the dynamics of agricultural trade specialization for the EU and China respectively. An international trade gravity model is also utilized to investigate the influence of selected economic factors (i.e. the geographic distance, institutional distance, GDP, etc.) on agricultural products’ trade flows from the viewpoint of the EU. The results are carried out under the help of three econometrics estimation models, i.e. a Pooled OLS model, LSDV model, and FGLS model. In addition, by using an econometrics prediction function, the agricultural trade potential has been estimated at EU member country level vis-à-vis China. Combining all the research results of this study, agricultural trade policy recommendations for both the EU and China are carried out by applying Porter’s SWOT analysis tool. In general, this study has confirmed that there are still many unexplored agricultural trade opportunities between the EU and China and the EU-China economic relationship could be further strengthened by developing their promising EU-China agricultural trade relations, and working on reducing or even eliminating many barriers that impede EU-China agricultural trade development