Mid-air haptic rendering of 2D geometric shapes with a dynamic tactile pointer

An important challenge that affects ultrasonic midair haptics, in contrast to physical touch, is that we lose certain exploratory procedures such as contour following. This makes the task of perceiving geometric properties and shape identification more difficult. Meanwhile, the growing interest in mid-air haptics and their application to various new areas requires an improved understanding of how we perceive specific haptic stimuli, such as icons and control dials in mid-air. We address this challenge by investigating static and dynamic methods of displaying 2D geometric shapes in mid-air. We display a circle, a square, and a triangle, in either a static or dynamic condition, using ultrasonic mid-air haptics. In the static condition, the shapes are presented as a full outline in mid-air, while in the dynamic condition, a tactile pointer is moved around the perimeter of the shapes. We measure participants’ accuracy and confidence of identifying shapes in two controlled experiments (n1 = 34, n2 = 25). Results reveal that in the dynamic condition people recognise shapes significantly more accurately, and with higher confidence. We also find that representing polygons as a set of individually drawn haptic strokes, with a short pause at the corners, drastically enhances shape recognition accuracy. Our research supports the design of mid-air haptic user interfaces in application scenarios such as in-car interactions or assistive technology in education

Ultrasonic mid-air haptic technology in context of science communication

This dissertation charts opportunities and challenges of engaging people with learning about science through the use of mid-air haptic technology. To that end, research has been carried out at the intersection of three multidisciplinary fields: Science Communication, Haptics, and Human-Computer Interaction. For science communication to be effective, different tools are required for different audiences. For example, when a child pours cold milk into hot tea and sips a warm beverage, we can raise awareness of the haptic experience; triggering interest and facilitating learning about thermal equilibrium. Not every scientific concept may be explained through changing temperature, and not everybody likes tea, but the principle of haptic experience facilitated public engagement with science remains a valid basis to examine. Science communicators seek new technological solutions and innovative modalities of communication, some of which include haptic technology and touch interaction. Ultrasonic mid-air haptic technology is a novel tool, which enables the creation of programable, invisible, cutaneous tactile sensations on an airborne interface between humans and the digital world. Mid-air haptic sensations may bring many benefits when used in science communication, but these have not yet been systematically studied

"Customization is Key": Four Characteristics of Textual Affordances for Accessible Data Visualization

Current best practices recommend using textual descriptions to make data visualizations accessible to blind and low vision (BLV) screen reader users. While recent research has explored laying such descriptions out hierarchically to enable reading varying levels of detail, the textual descriptions remain fixed: their syntax and semantics are set by the visualization author or tool, and cannot be changed by a BLV user based on their preferences or task-specific needs. In this paper, we explore four characteristics of customizations for hierarchical textual descriptions of visualizations: presence, or what content is present in the description; verbosity, or the length and conciseness of the content; ordering, or the sequencing of content; and, duration, or how long a particular customization lasts. We instantiate these methods as extensions to Olli, an open source library that converts web-based visualizations into hierarchical textual structures, and evaluate our work through a mixed-methods study with 13 BLV participants. Users reported that customization is crucial to their agency and that being able to change the four characteristics helps them efficiently carry out their desired tasks on the data. However, differences in preferred defaults, prior experiences, and enthusiasm for customization indicate that there is no one-size-fits-all system even for customization itself: both accessible data visualizations and user interfaces for customizing them must be flexible enough to meet a variety of needs.Comment: 24 pages. 6 figures. 2 table

The transcription factor EGR2 is the molecular linchpin connecting STAT6 activation to the late, stable epigenomic program of alternative macrophage polarization

Macrophages polarize into functionally distinct subtypes while responding to microenvironmental cues. The identity of proximal transcription factors (TFs) downstream from the polarization signals are known, but their activity is typically transient, failing to explain the long-term, stable epigenomic programs developed. Here, we mapped the early and late epigenomic changes of interleukin-4 (IL-4)-induced alternative macrophage polarization. We identified the TF, early growth response 2 (EGR2), bridging the early transient and late stable gene expression program of polarization. EGR2 is a direct target of IL-4-activated STAT6, having broad action indispensable for 77% of the induced gene signature of alternative polarization, including its autoregulation and a robust, downstream TF cascade involving PPARG. Mechanistically, EGR2 binding results in chromatin opening and the recruitment of chromatin remodelers and RNA polymerase II. Egr2 induction is evolutionarily conserved during alternative polarization of mouse and human macrophages. In the context of tissue resident macrophages, Egr2 expression is most prominent in the lung of a variety of species. Thus, EGR2 is an example of an essential and evolutionarily conserved broad acting factor, linking transient polarization signals to stable epigenomic and transcriptional changes in macrophages

The Epigenetic State of IL-4-Polarized Macrophages Enables Inflammatory Cistromic Expansion and Extended Synergistic Response to TLR Ligands

Prior exposure to microenvironmental signals could fundamentally change the response of macrophages to subsequent stimuli. It is believed that T helper-2 (Th2)-cell-type cytokine interleukin-4 (IL-4) and Toll-like receptor (TLR) ligand-activated transcriptional programs mutually antagonize each other, and no remarkable convergence has been identified between them. In contrast, here, we show that IL-4-polarized macrophages established a hyperinflammatory gene expression program upon lipopolysaccharide (LPS) exposure. This phenomenon, which we termed extended synergy, was supported by IL-4-directed epigenomic remodeling, LPS-activated NF-κB-p65 cistrome expansion, and increased enhancer activity. The EGR2 transcription factor contributed to the extended synergy in a macrophage-subtype-specific manner. Consequently, the previously alternatively polarized macrophages produced increased amounts of immune-modulatory factors both in vitro and in vivo in a murine Th2 cell-type airway inflammation model upon LPS exposure. Our findings establish that IL-4-induced epigenetic reprogramming is responsible for the development of inflammatory hyperresponsiveness to TLR activation and contributes to lung pathologies

Rich Screen Reader Experiences for Accessible Data Visualization

Current web accessibility guidelines ask visualization designers to support screen readers via basic non-visual alternatives like textual descriptions and access to raw data tables. But charts do more than summarize data or reproduce tables; they afford interactive data exploration at varying levels of granularity -- from fine-grained datum-by-datum reading to skimming and surfacing high-level trends. In response to the lack of comparable non-visual affordances, we present a set of rich screen reader experiences for accessible data visualization and exploration. Through an iterative co-design process, we identify three key design dimensions for expressive screen reader accessibility: structure, or how chart entities should be organized for a screen reader to traverse; navigation, or the structural, spatial, and targeted operations a user might perform to step through the structure; and, description, or the semantic content, composition, and verbosity of the screen reader's narration. We operationalize these dimensions to prototype screen-reader-accessible visualizations that cover a diverse range of chart types and combinations of our design dimensions. We evaluate a subset of these prototypes in a mixed-methods study with 13 blind and low vision readers. Our findings demonstrate that these designs help users conceptualize data spatially, selectively attend to data of interest at different levels of granularity, and experience control and agency over their data analysis process. An accessible HTML version of this paper is available at: http://vis.csail.mit.edu/pubs/rich-screen-reader-vis-experiences.Comment: An accessible HTML version of this paper is available at: http://vis.csail.mit.edu/pubs/rich-screen-reader-vis-experience