Kirigami Actuators

Thin elastic sheets bend easily and, if they are patterned with cuts, can deform in sophisticated ways. Here we show that carefully tuning the location and arrangement of cuts within thin sheets enables the design of mechanical actuators that scale down to atomically-thin 2D materials. We first show that by understanding the mechanics of a single, non-propagating crack in a sheet we can generate four fundamental forms of linear actuation: roll, pitch, yaw, and lift. Our analytical model shows that these deformations are only weakly dependent on thickness, which we confirm with experiments at centimeter scale objects and molecular dynamics simulations of graphene and MoS$_{2}$ nanoscale sheets. We show how the interactions between non-propagating cracks can enable either lift or rotation, and we use a combination of experiments, theory, continuum computational analysis, and molecular dynamics simulations to provide mechanistic insights into the geometric and topological design of kirigami actuators.Comment: Soft Matter, 201

Exploring the Impact of a Gamified Exercise Platform to Support Healthy Ageing:Home-Based Study with Older Adults

Active ageing is an increasingly important concept within society due to the ageing of the world population and search for enhanced quality of life. Technological resources such as serious games can be used as a means to promote healthier lifestyle and ageing, particularly in older adults. This study intended to explore the effects of using a digital approach composed of serious games to support physical and cognitive exercise at home, to support healthy ageing. Eleven older adults voluntarily participated in an eight-day home-based study. The aim of the study was to explore the feasibility of the digital approach in autonomous sessions at home, by measuring satisfaction and motivation, and assessing the impact of different gamification strategies. The results showed that participants exercised autonomously on average on 5.5 out of the 8 days. Each session had an average duration of 35 minutes. Moreover, participants reported an average satisfaction of 80.0% throughout the sessions. Yet, the findings indicate that system usability should still be improved. Participants provided suggestions towards an easier user experience, pointing for example to the importance of personalized exercise plans. The findings suggest that gamification strategies focused on multi-joint and dynamic exercises were preferred over single limb and more monotonous exercises. The current study highlights the potential of home-based digital solutions to support healthy ageing in older adults and provide suggestions for future endeavors in this area.</p

Rethinking Leahy’s Emotional Schema Scale (LESS): Results from the Portuguese Adaptation of the LESS

This study aims to contribute to the study of emotional schemas, through the adaptation of the Leahy Emotional Schema Scale (LESS) to Portuguese. The LESS is a 50 item self-report with 14 theoretical dimensions, representing concepts, evaluations, attributions of emotions, and strategies of emotion regulation (Leahy in Cognit Behav Pract 9(3):177–190, 2002. https://doi.org/10.1016/S1077-7229(02)80048- 7). Translation, back-translation and pilot assessment of LESS’s Portuguese version were completed. Data was collected online with 396 participants. An exploratory principal component analysis was conducted. Parallel analysis revealed a 5-component structure, which after the deletion of eight items generated a fnal solution explaining 48% of the variance. Components internal consistency was adequate and convergent validity supported with signifcant correlations with difculties in emotional regulation and emotional processing, and psychopathology. It presents dimensions that are highly relevant for assessment, case conceptualization and clinical decision making. Although this scale is related to a specifc cognitive theory, the construct and its subscales may be useful beyond the psychotherapeutic model, stressing the transtheoretical potential of the scale.info:eu-repo/semantics/publishedVersio

Multinma: A comprehensive R package for network meta-analysis of survival outcomes with aggregate data, individual patient data, or a mixture of both

IntroductionSurvival or time-to-event outcomes are commonplace in disease areas such as oncology. Healthcare decision makers require estimates of relative efficacy between different treatment options, however treatments of interest are frequently not all compared in head-to-head randomised controlled trials, and so indirect comparison and network meta-analysis (NMA) methods are required to synthesise evidence from a connected network of trials and treatments. An extension of NMA, multilevel network meta-regression (ML-NMR), is increasingly used to account for differences in effect modifiers between populations where individual patient data are available from one or more trials. However, to date there has been no user-friendly software package that can perform NMA or ML-NMR with survival outcomes; instead analysts have needed to rely on complex bespoke modelling code. MethodsA recent update to the multinma R package provides a user-friendly suite of models and tools for synthesising survival outcomes from multiple trials, with aggregate data, individual patient data, or mixtures of both. Models are fitted in a Bayesian framework using Stan. A full range of parametric proportional hazards and accelerated failure time survival distributions are implemented, along with flexible baseline hazard models via M-splines or piecewise exponential hazards with a novel random walk shrinkage prior that avoids overfitting. Shape parameters may be stratified or regressed on treatment arm and/or covariates to relax proportionality. Right, left, and interval censoring, and delayed entry are all supported.ResultsWe present analyses of two case studies using the multinma package. First, we performed a NMA of published aggregate data from a network of treatments for advanced non-small cell lung cancer using flexible M-spline baseline hazards. We introduced treatment effects onto the spline coefficients to account for non-proportional hazards, and produced estimated survival curves in a target population required for further economic modelling.Second, we performed a ML-NMR using a mixture of individual patient data and aggregate data from a network of treatments for newly-diagnosed multiple myeloma. We adjusted for effect-modifying covariates, and produced population-adjusted estimates for target populations of interest to decision-making. Covariate adjustment removed evidence for non-proportional hazards that was present in unadjusted models.ConclusionsThe multinma package makes NMA and ML-NMR methods accessible to a broad audience. The latest update to include a suite of functionality for survival analysis facilitates application of these methods to widespread settings such as oncology, where until now there was no user-friendly software available

Phase diagram for non-axisymmetric plasma balls

Plasma balls and rings emerge as fluid holographic duals of black holes and black rings in the hydrodynamic/gravity correspondence for the Scherk-Schwarz AdS system. Recently, plasma balls spinning above a critical rotation were found to be unstable against m-lobed perturbations. In the phase diagram of stationary solutions the threshold of the instability signals a bifurcation to a new phase of non-axisymmetric configurations. We find explicitly this family of solutions and represent them in the phase diagram. We discuss the implications of our results for the gravitational system. Rotating non-axisymmetric black holes necessarily radiate gravitational waves. We thus emphasize that it would be important, albeit possibly out of present reach, to have a better understanding of the hydrodynamic description of gravitational waves and of the gravitational interaction between two bodies. We also argue that it might well be that a non-axisymmetric m-lobed instability is also present in Myers-Perry black holes for rotations below the recently found ultraspinning instability.Comment: 1+22 pages, 3 figures. v2: minor corrections and improvements, matches published versio

Natural pigments of anthocyanin and betalain for coloring soy-based yogurt alternative

The aim of this work was to evaluate the color stability of betalain- and anthocyanin-rich extracts in yogurt-like fermented soy, in order to develop a preliminary understanding of how these pigments behave in this type of food system during storage for 21 days at 4 °C. Thus, the extracts of red beetroot, opuntia, hibiscus and red radish were integrated into the yogurt-like fermented soy in two different ways—directly after lyophilization, and encapsulated in nanosystems based in soybean lecithin—as this approach has never been used to further increase the value and potential of the dairy-free alternatives of yogurt-like fermented soy. The results showed that non-encapsulated betalain-rich extracts from red radish are the most promising for coloring yogurt-like fermented soy. However, encapsulated opuntia extracts can also be an alternative to supplement the soy fermented beverages with betalains, without changing significantly the color of the system but giving all its health benefits, due to the protection of the pigments by nanoencapsulation.This research was funded by COMPETE 2020 program, co-financed by the FEDER and the European Union, PTDC/ASP-AGR/30154/2017 (POCI-01-0145-FEDER-030154). Foundation for Science and Technology (FCT, Portugal), and FEDER-COMPETE-QREN-EU funded research centers CQ-UM (UID/QUI/00686/2019), CF-UM-UP (UID/FIS/04650/2019) and REQUIMTE (UIDB/50006/2020)

Transport equations for the inflationary trispectrum

We use transport techniques to calculate the trispectrum produced in multiple-field inflationary models with canonical kinetic terms. Our method allows the time evolution of the local trispectrum parameters, tauNL and gNL, to be tracked throughout the inflationary phase. We illustrate our approach using examples. We give a simplified method to calculate the superhorizon part of the relation between field fluctuations on spatially flat hypersurfaces and the curvature perturbation on uniform density slices, and obtain its third-order part for the first time. We clarify how the 'backwards' formalism of Yokoyama et al. relates to our analysis and other recent work. We supply explicit formulae which enable each inflationary observable to be computed in any canonical model of interest, using a suitable first-order ODE solver.Comment: 24 pages, plus references and appendix. v2: matches version published in JCAP; typo fixed in Eq. (54

Characterization of phytoplankton by pigment analysis and the detection of toxic cyanobacteria in reservoirs with aquaculture production

Made available in DSpace on 2018-12-11T17:19:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01The intensified use of water bodies and reservoirs for aquaculture production has increased the need for monitoring and early warning of toxins from cyanobacteria. To minimize effects from toxins, simple and fast analytical monitoring methods are crucial. Here, the content of pigments and microcystins in 14 different strains of cyanobacteria cultured under different growth conditions was investigated to determine the influence of light and nutrient starvation on pigment/ chlorophyll a (chl a) ratios. The obtained pigment/chl a ratios were applied in the software CHEMTAX to calculate the biomass of toxic cyanobacteria, as well as other phytoplankton groups. CHEMTAX ratios from the laboratory cultures were applied to water samples collected during 4 sampling periods at 6 fish farms in different reservoirs in São Paulo State, Brazil. Cyanobacteria generally dominated in all reservoirs in all sampling periods and constituted on average 44 to 66% of the average phytoplankton biomass. The concentrations of microcystins were significantly correlated with the chl a concentrations of cyanobacteria and showed that the pigment method can be used to detect microcystin-producing cyanobacteria in these Brazilian reservoirs. When the concentration of cyanobacteria in the reservoirs was above 4 μg chl a l-1, microcystins were always detected. Our results show that pigment analysis can be used to provide fast and reliable results for the early warning, the presence and potential risk of toxic cyanobacteria in freshwater reservoirs used for aqua culture.Environment and Toxicology DHISão Paulo State Agribusiness Agency TechnologySection of Microbial Ecology and Biotechnology Department of Plant and Environmental Sciences University of CopenhagenFicology Department Botanical InstituteUNESP Campus Botucatu Institute of Biosciences Parasitology DepartmentUNESP Campus Botucatu Institute of Biosciences Parasitology Departmen