Dynamical system representation, generation, and recognition of basic oscillatory motion gestures

We present a system for generation and recognition of oscillatory gestures. Inspired by gestures used in two representative human-to-human control areas, we consider a set of oscillatory motions and refine from them a 24 gesture lexicon. Each gesture is modeled as a dynamical system with added geometric constraints to allow for real time gesture recognition using a small amount of processing time and memory. The gestures are used to control a pan-tilt camera neck. We propose extensions for use in areas such as mobile robot control and telerobotics

Dynamic System Representation of Basic and Non-Linear in Parameters Oscillatory Motion Gestures

We present a system for generation and recognition of oscillatory gestures. Inspired by gestures used in two representative human-to-human control areas, we consider a set of oscillatory (circular) motions and refine from them a 24 gestures lexicon. Each gesture is modeled as a dynamic system with added geometric constraints to allow for real time gesture recognition using a small amount of processing time and memory. The gestures are used to control a pan-tilt camera neck. The gesture lexicon is then enhanced to include non-linear in parameter ( come here ) gesture representations. An enhancement is suggested which would enable the system to be trained to recognized previously unidentified yet consistent human generated oscillatory motion gestures

Possible Transport of Basal Debris to the Surface of a Mid-Latitude Glacier on Mars

International audience<p><strong>Introduction:</strong> We observe internal flow structures within a viscous flow feature (VFF; 51.24°W, 42.53°S) interpreted as a debris-covered glacier in Nereidum Montes, Mars. The structures are exposed in the wall of a gully that is incised through the VFF, parallel to its flow-direction. They are near to the glacier terminus and appear to connect its deep interior (and possibly its bed) to arcuate flow-transverse foliations on its surface. Such foliations are common on VFF surfaces, but their relation to VFF-internal structures and ice flow is poorly understood. The VFF-internal structures we observe are reminiscent of up-glacier dipping shear structures that transport basal debris to glacier surfaces on Earth.</p><p>Subglacial environments on Mars are of astrobiological interest due to the availability of water ice and shelter from Mars’ surface radiation environment. However, current limitations in drilling technology prevent their direct exploration. If debris on VFF surfaces contains a component of englacial and/or subglacial debris, those materials could be sampled without access to the subsurface. This could reduce the potential cost and complexity of future missions that aim to explore englacial and subglacial environments on Mars.</p><p><strong>Methods: </strong>We use a 1 m/pixel digital elevation model (DEM) derived from 25 cm/pixel High Resolution Imaging Science Experiment (HiRISE) stereo-pair images, and a false-colour (merged IRB) HiRISE image. We measured the dip and strike of the VFF-internal structures using ArcGIS 10.7 and QGIS software. We also input the DEM (and an inferred glacier bed topography derived from it) into ice flow simulations using the Ice Sheet System Model, assuming no basal sliding and present-day mean annual surface temperature (210K).</p><p><strong>Results and Discussion: </strong>The VFF-internal structures dip up-glacier at ~20° from the bed. This is inconsistent with their formation by bed-parallel ice-accumulation layering without modification by ice flow. The VFF-internal structures and surface foliations are spectrally ‘redder’ than adjacent VFF portions, which appear ‘bluer’. This could result from differences in debris concentration and/or surficial dust trapping between the internal structures and the bulk VFF. Modelling experiments suggest that the up-glacier-dipping structures occur at the onset of a compressional regime as ice flow slowed towards the VFF terminus.</p><p>In cold-based glaciers on Earth, up-glacier-dipping folds are common approaching zones of enhanced ice rigidity near the glacier margin. Where multiple folds co-exist, the outermost typically comprises basal ice with a component of subglacial debris entrained in the presence of interfacial films of liquid water at sub-freezing temperatures. In polythermal glaciers, debris-rich up-glacier-dipping thrust faults form where sliding wet-based ice converges with cold-based ice.</p><p><strong>Conclusions: </strong>We propose that the observed up-glacier-dipping VFF-internal structures are englacial shear zones formed by compressional ice flow. They could represent transport pathways for englacial and subglacial material to the VFF surface. The majority of extant mid-latitude VFF on Mars are thought to have been perennially cold-based; thus we favour the hypothesis that the VFF-internal structures are folds formed under a cold-based thermal regime. Under this mechanism, the outermost surface foliation, and its corresponding VFF-internal structure, is the most likely to contain subglacial debris.</p&gt

Internal Structure of a Glacier on Mars Revealed by Gully Incision

International audienceDebris transport from / A Mars glacier bed to / Flowlines on surface

Radio Observations of the Hubble Deep Field South region: I. Survey Description and Initial Results

This paper is the first of a series describing the results of the Australia Telescope Hubble Deep Field South (ATHDFS) radio survey. The survey was conducted at four wavelengths - 20, 11, 6, and 3 cm, over a 4-year period, and achieves an rms sensitivity of about 10 microJy at each wavelength. We describe the observations and data reduction processes, and present data on radio sources close to the centre of the HDF-S. We discuss in detail the properties of a subset of these sources. The sources include both starburst galaxies and galaxies powered by an active galactic nucleus, and range in redshift from 0.1 to 2.2. Some of them are characterised by unusually high radio-to-optical luminosities, presumably caused by dust extinction.Comment: Accepted by AJ. 32 pages, 4 tables, 3 figures. PDF with full-resolution figures is on http://www.atnf.csiro.au/people/rnorris/N197.pd

Live imaging molecular changes in junctional tension upon VE-cadherin in zebrafish

Forces play diverse roles in vascular development, homeostasis and disease. VE-cadherin at endothelial cell-cell junctions links the contractile acto-myosin cytoskeletons of adjacent cells, serving as a tension-transducer. To explore tensile changes across VE-cadherin in live zebrafish, we tailored an optical biosensor approach, originally established in vitro. We validate localization and function of a VE-cadherin tension sensor (TS) in vivo. Changes in tension across VE-cadherin observed using ratio-metric or lifetime FRET measurements reflect acto-myosin contractility within endothelial cells. Furthermore, we apply the TS to reveal biologically relevant changes in VE-cadherin tension that occur as the dorsal aorta matures and upon genetic and chemical perturbations during embryonic development

A myosin chaperone, UNC-45A, is a novel regulator of intestinal epithelial barrier integrity and repair

The actomyosin cytoskeleton serves as a key regulator of the integrity and remodeling of epithelial barriers by controlling assembly and functions of intercellular junctions and cell-matrix adhesions. Although biochemical mechanisms that regulate the activity of non-muscle myosin II (NM-II) in epithelial cells have been extensively investigated, little is known about assembly of the contractile myosin structures at the epithelial adhesion sites. UNC-45A is a cytoskeletal chaperone that is essential for proper folding of NM-II heavy chains and myofilament assembly. We found abundant expression of UNC-45A in human intestinal epithelial cell (IEC) lines and in the epithelial layer of the normal human colon. Interestingly, protein level of UNC-45A was decreased in colonic epithelium of patients with ulcerative colitis. CRISPR/Cas9-mediated knock-out of UNC-45A in HT-29cf8 and SK-CO15 IEC disrupted epithelial barrier integrity, impaired assembly of epithelial adherence and tight junctions and attenuated cell migration. Consistently, decreased UNC-45 expression increased permeability of the Drosophila gut in vivo. The mechanisms underlying barrier disruptive and anti-migratory effects of UNC-45A depletion involved disorganization of the actomyosin bundles at epithelial junctions and the migrating cell edge. Loss of UNC-45A also decreased contractile forces at apical junctions and matrix adhesions. Expression of deletion mutants revealed roles for the myosin binding domain of UNC-45A in controlling IEC junctions and motility. Our findings uncover a novel mechanism that regulates integrity and restitution of the intestinal epithelial barrier, which may be impaired during mucosal inflammation.Peer reviewe

Continuum Halos in Nearby Galaxies -- an EVLA Survey (CHANG-ES) -- II: First Results on NGC 4631

We present the first results from the CHANG-ES survey, a new survey of 35 edge-on galaxies to search for both in-disk as well as extra-planar radio continuum emission. The motivation and science case for the survey are presented in a companion paper (Paper I). In this paper (Paper II), we outline the observations and data reduction steps required for wide-band calibration and mapping of EVLA data, including polarization, based on C-array test observations of NGC 4631. With modest on-source observing times (30 minutes at 1.5 GHz and 75 minutes at 6 GHz for the test data) we have achieved best rms noise levels of 22 and 3.5 $\mu$Jy beam$^{-1}$ at 1.5 GHz and 6 GHz, respectively. New disk-halo features have been detected, among them two at 1.5 GHz that appear as loops in projection. We present the first 1.5 GHz spectral index map of NGC 4631 to be formed from a single wide-band observation in a single array configuration. This map represents tangent slopes to the intensities within the band centered at 1.5 GHz, rather than fits across widely separated frequencies as has been done in the past and is also the highest spatial resolution spectral index map yet presented for this galaxy. The average spectral index in the disk is $\bar\alpha_{1.5 GHz}\,=\,-0.84\,\pm\,0.05$ indicating that the emission is largely non-thermal, but a small global thermal contribution is sufficient to explain a positive curvature term in the spectral index over the band. Two specific star forming regions have spectral indices that are consistent with thermal emission. Polarization results (uncorrected for internal Faraday rotation) are consistent with previous observations and also reveal some new features. On broad scales, we find strong support for the notion that magnetic fields constrain the X-ray emitting hot gas.Comment: Accepted to the Astronomical Journal, Version 2 changes: Added acknowledgement to NRA

Spontaneous and deliberate future thinking: A dual process account

© 2019 Springer Nature.This is the final published version of an article published in Psychological Research, licensed under a Creative Commons Attri-bution 4.0 International License. Available online at: https://doi.org/10.1007/s00426-019-01262-7.In this article, we address an apparent paradox in the literature on mental time travel and mind-wandering: How is it possible that future thinking is both constructive, yet often experienced as occurring spontaneously? We identify and describe two ‘routes’ whereby episodic future thoughts are brought to consciousness, with each of the ‘routes’ being associated with separable cognitive processes and functions. Voluntary future thinking relies on controlled, deliberate and slow cognitive processing. The other, termed involuntary or spontaneous future thinking, relies on automatic processes that allows ‘fully-fledged’ episodic future thoughts to freely come to mind, often triggered by internal or external cues. To unravel the paradox, we propose that the majority of spontaneous future thoughts are ‘pre-made’ (i.e., each spontaneous future thought is a re-iteration of a previously constructed future event), and therefore based on simple, well-understood, memory processes. We also propose that the pre-made hypothesis explains why spontaneous future thoughts occur rapidly, are similar to involuntary memories, and predominantly about upcoming tasks and goals. We also raise the possibility that spontaneous future thinking is the default mode of imagining the future. This dual process approach complements and extends standard theoretical approaches that emphasise constructive simulation, and outlines novel opportunities for researchers examining voluntary and spontaneous forms of future thinking.Peer reviewe