Does It Par-<i>tickle</i>?:Investigating the Relationship Between Mid-Air Haptics and Visual Representations of Surface Textures

Mid-air haptic feedback technology produces tactile sensations that are felt without the need for physical interactions. However, mid-air haptic experiences need to be congruent with visual cues to reflect user expectations. To overcome this, we investigate how to visually present properties of objects, so that what one feels is a more accurate prediction of what one sees. Specifically, this paper investigates the relationship between 8 visual parameters of a point-cloud representation of a surface (particle color, size, distribution, etc.) and 4 mid-air haptic spatial modulation frequencies (20, 40, 60 and 80 Hz). Our results and analysis reveal a statistical significance between low and high-frequency modulations and particle density, particle bumpiness (depth) and particle arrangement (randomness)

Does it par-tickle?: Investigating the relationship between mid-air haptics and visual representations of surface textures.

Mid-air haptic feedback technology produces tactile sensations that are felt without the need for physical interactions. However, mid-air haptic experiences need to be congruent with visual cues to reflect user expectations. To overcome this, we investigate how to visually present properties of objects, so that what one feels is a more accurate prediction of what one sees. Specifically, this paper investigates the relationship between 8 visual parameters of a point-cloud representation of a surface (particle color, size, distribution, etc.) and 4 mid-air haptic spatial modulation frequencies (20, 40, 60 and 80 Hz). Our results and analysis reveal a statistical significance between low and high-frequency modulations and particle density, particle bumpiness (depth) and particle arrangement (randomness)

Particle-ularly Haptics: Investigating the Relationship Between Visual Feedback and Mid-Air Haptic Texture

Mid-air haptic feedback technology produces tactile sensations that are felt without the need for physical interactions, and bridges the gap with digital interactions, by making the virtual feel real. However, existing mid-air haptic experiences often do not reflect user expectations in terms of congruence between visual and haptic stimuli. To overcome this, we investigate how to better present the visual properties of objects, so that what one feels is a more accurate prediction of what one sees. In the following demonstration, we present an approach that allows users to fine tune the visual appearance of different textured surfaces, and then match these to corresponding mid-air haptic stimuli in order to improve visual-haptic congruenc

An Exploration of Just Noticeable Differences in Mid-Air Haptics

Mid-air haptic feedback technology produces tactile sensations that are felt without the need for physical interactions, wearables or controllers. When designing mid-air haptic stimuli, it is important that they are sufficiently different in terms of their perceived sensation.This paper presents the results of two user studies on mid-air haptic feedback technology, with a focus on the sensations of haptic strength and haptic roughness. More specifically, we used the acoustic pressure intensity and the rotation frequency of the mid-air haptic stimulus as proxies to the two sensations of interest and investigated their Just Noticeable Difference (JND) and Weber fractions. Our results indicate statistical significance in the JND for frequency, with a finer resolution compared to intensity. Moreover, correlations are observed in terms of participants' sensitivity to small changes across the different stimuli presented. We conclude that frequency and intensity are mid-air haptic dimensions of depth 5 and 3, respectively, that we can use for the design of distinct stimuli that convey perceptually different tactile information to the user

Reproducible model development in the Cardiac Electrophysiology Web Lab

The modelling of the electrophysiology of cardiac cells is one of the most mature areas of systems biology. This extended concentration of research effort brings with it new challenges, foremost among which is that of choosing which of these models is most suitable for addressing a particular scientific question. In a previous paper, we presented our initial work in developing an online resource for the characterisation and comparison of electrophysiological cell models in a wide range of experimental scenarios. In that work, we described how we had developed a novel protocol language that allowed us to separate the details of the mathematical model (the majority of cardiac cell models take the form of ordinary differential equations) from the experimental protocol being simulated. We developed a fully-open online repository (which we termed the Cardiac Electrophysiology Web Lab) which allows users to store and compare the results of applying the same experimental protocol to competing models. In the current paper we describe the most recent and planned extensions of this work, focused on supporting the process of model building from experimental data. We outline the necessary work to develop a machine-readable language to describe the process of inferring parameters from wet lab datasets, and illustrate our approach through a detailed example of fitting a model of the hERG channel using experimental data. We conclude by discussing the future challenges in making further progress in this domain towards our goal of facilitating a fully reproducible approach to the development of cardiac cell models

Rapid Characterization of hERG Channel Kinetics II: Temperature Dependence

© 2019 Biophysical Society Ion channel behavior can depend strongly on temperature, with faster kinetics at physiological temperatures leading to considerable changes in currents relative to room temperature. These temperature-dependent changes in voltage-dependent ion channel kinetics (rates of opening, closing, inactivating, and recovery) are commonly represented with Q10 coefficients or an Eyring relationship. In this article, we assess the validity of these representations by characterizing channel kinetics at multiple temperatures. We focus on the human Ether-à-go-go-Related Gene (hERG) channel, which is important in drug safety assessment and commonly screened at room temperature so that results require extrapolation to physiological temperature. In Part I of this study, we established a reliable method for high-throughput characterization of hERG1a (Kv11.1) kinetics, using a 15-second information-rich optimized protocol. In this Part II, we use this protocol to study the temperature dependence of hERG kinetics using Chinese hamster ovary cells overexpressing hERG1a on the Nanion SyncroPatch 384PE, a 384-well automated patch-clamp platform, with temperature control. We characterize the temperature dependence of hERG gating by fitting the parameters of a mathematical model of hERG kinetics to data obtained at five distinct temperatures between 25 and 37°C and validate the models using different protocols. Our models reveal that activation is far more temperature sensitive than inactivation, and we observe that the temperature dependency of the kinetic parameters is not represented well by Q10 coefficients; it broadly follows a generalized, but not the standardly-used, Eyring relationship. We also demonstrate that experimental estimations of Q10 coefficients are protocol dependent. Our results show that a direct fit using our 15-s protocol best represents hERG kinetics at any given temperature and suggests that using the Generalized Eyring theory is preferable if no experimental data are available to derive model parameters at a given temperature

Land systems as surrogates for biodiversity in conservation planning

Environmental surrogates (land classes) for the distribution of biodiversity are increasingly being used for conservation planning. However; data that demonstrate coincident patterns in land classes and biodiversity are limited. We ask the overall question, "Are land systems effective surrogates for the spatial configuration of biodiversity for conservation planning?" and we address three specific questions: (1) Do different land systems represent different biological assemblages.? (2) Do biological assemblages on the same land system remain similar with increasing geographic separation? and (3) Do biological assemblages on the same land system remain similar with increasing land system isolation? Vascular plants, invertebrates, and microbiota were surveyed from 24 sites in four land systems in and northwest New South Wales, Australia. Within each land system, sites were located to give a hierarchy of inter-site distances, and land systems were classified as either "low isolation" (large and continuous) or "high isolation" (small patches interspersed among other land systems). Each type of land system supported components of biodiversity either not found, or found infrequently, on other land systems, suggesting that land systems function as surrogates for biodiversity, and that conservation-area networks representing land-system diversity will also represent biological diversity. However, the majority of taxa were found on more than one land-system type, suggesting that a large proportion of the plant, arthropod, and microbial biodiversity may be characterized by widespread species with low fidelity to particular land systems. Significant relationships between geographic distance among sites and differences among assemblages were revealed for all taxa except the microbiota. Therefore, as sites on the same land system were located farther apart, the assemblages at those sites became more different. This finding strongly suggests that conservation planning based on land-system diversity should also sample the geographic range occupied by each land system. Land-system isolation was not revealed to be a significant Source of variation in assemblage composition. Our research finds support for environmental surrogates for biodiversity in conservation planning, specifically the use of land systems and similarly derived land classifications. However, the need for explicit modeling of geographic distance in conservation planning is clearly indicated

A Lagerstätte from Australia provides insight into the nature of Miocene mesic ecosystems

Reduced precipitation in the Miocene triggered the geographic contraction of rainforest ecosystems around the world. In Australia, this change was particularly pronounced; mesic rainforest ecosystems that once dominated the landscape transformed into the shrublands, grasslands, and deserts of today. A lack of well-preserved fossils has made it difficult to understand the nature of Australian ecosystems before the aridification. Here, we report on an exceptionally well-preserved rainforest biota from New South Wales, Australia. This Konservat-Lagerstätte hosts a rich diversity of microfossils, plants, insects, spiders, and vertebrate remains preserved in goethite. We document evidence for several species interactions including predation, parasitism, and pollination. The fossils are indicative of an oxbow lake in a mesic rainforest and suggest that rainforest distributions have shifted since the Miocene. The variety of fossils preserved, together with high fidelity of preservation, allows for unprecedented insights into the mesic ecosystems that dominated Australia during the Miocene