7,569 research outputs found
Gestalt Theory in Visual Screen Design — A New Look at an old subject
Although often presented as a single basis for educational visual screen design, Gestalt theory is not a single small set of visual principles uniformly applied by all designers. In fact, it appears that instructional visual design literature often deals with only a small set of Gestalt laws. In this project Gestalt literature was consulted to distil the most relevant Gestalt laws for educational visual screen design. Eleven laws were identified. They deal with balance/symmetry, continuation, closure, figure-ground, focal point, isomorphic correspondence, prŠgnanz, proximity, similarity, simplicity, and unity/harmony. To test the usefulness of these laws in visual screen design they were applied to the redesign of an instructional multimedia application, 'WoundCare', designed to teach nursing students wound management. The basic text-based screens in the original WoundCare application were replaced with graphical user interface screens, that were designed according to these principles. The new screen designs were then evaluated by asking students and others to compare the designs. The viewers were also asked to rate directly the value of using the eleven Gestalt design principles in the redesign, both for improving the product's appearance and improving its value for learning. The evaluation results were overwhelmingly positive. Both the new design and the value of applying the eleven Gestalt laws to improve learning were strongly supported by the students' opinions. However, some differences in the value of applying particular Gestalt laws to the interface design were identified and this forms a useful direction for future research
Hyperbolic Organizational Identity and Identity of Digital Artifacts: A Comparative Study of Healthcare Innovations
As digital technologies move toward the core of an organization’s offerings, the identity of many contemporary organizations is now born in association with the digital technology that characterizes them. Entrepreneurs largely rely on setting up high expectations to attract initial resources to materialize the idea for their digital innovation. However, such a tactic may be problematic when their eventual digital artifact contradicts their core organizational identity, leading to their legitimacy loss. In this ongoing study, we explore a novel phenomenon of hyperbolic organizational identity. Drawing on longitudinal archival sources, we conduct a comparative case study of IBM Watson and DeepMind, whose identities both became hyperbolic, yet experienced different outcomes in their healthcare innovations. From our findings to date, a preliminary dialectical process model is presented that depicts the interplay between organizational and technical identities of the digital artifact in leading to the formation and change in hyperbolic organizational identity
Fast sensing of double-dot charge arrangement and spin state with an rf sensor quantum dot
Single-shot measurement of the charge arrangement and spin state of a double
quantum dot are reported, with measurement times down to ~ 100 ns. Sensing uses
radio-frequency reflectometry of a proximal quantum dot in the Coulomb blockade
regime. The sensor quantum dot is up to 30 times more sensitive than a
comparable quantum point contact sensor, and yields three times greater signal
to noise in rf single-shot measurements. Numerical modeling is qualitatively
consistent with experiment and shows that the improved sensitivity of the
sensor quantum dot results from reduced screening and lifetime broadening.Comment: related papers at http://marcuslab.harvard.ed
Evidence of topological superconductivity in planar Josephson junctions
Majorana zero modes are quasiparticle states localized at the boundaries of
topological superconductors that are expected to be ideal building blocks for
fault-tolerant quantum computing. Several observations of zero-bias conductance
peaks measured in tunneling spectroscopy above a critical magnetic field have
been reported as experimental indications of Majorana zero modes in
superconductor/semiconductor nanowires. On the other hand, two dimensional
systems offer the alternative approach to confine Ma jorana channels within
planar Josephson junctions, in which the phase difference {\phi} between the
superconducting leads represents an additional tuning knob predicted to drive
the system into the topological phase at lower magnetic fields. Here, we report
the observation of phase-dependent zero-bias conductance peaks measured by
tunneling spectroscopy at the end of Josephson junctions realized on a InAs/Al
heterostructure. Biasing the junction to {\phi} ~ {\pi} significantly reduces
the critical field at which the zero-bias peak appears, with respect to {\phi}
= 0. The phase and magnetic field dependence of the zero-energy states is
consistent with a model of Majorana zero modes in finite-size Josephson
junctions. Besides providing experimental evidence of phase-tuned topological
superconductivity, our devices are compatible with superconducting quantum
electrodynamics architectures and scalable to complex geometries needed for
topological quantum computing.Comment: main text and extended dat
Rho-A prenylation and signaling link epithelial homeostasis to intestinal inflammation
Although defects in intestinal barrier function are discussed as a key pathogenic factor in patients with inflammatory bowel diseases (IBD), the molecular pathways driving disease-specific alterations of intestinal epithelial cells (IECs) are largely unknown. Here, we performed a novel approach to characterize the transcriptome of IECs from IBD patients using a genome wide approach. We observed disease-specific alterations in IECs with markedly impaired Rho-A signaling in active IBD patients. Localization of epithelial Rho-A was shifted to the cytosol in IBD where Rho-A activation was suppressed due to reduced expression of the Rho-A prenylation enzyme GGTase-I. The functional relevance of this pathway was highlighted by studies in mice with conditional gene targeting in which deletion of RhoA or GGTase-I in IECs caused spontaneous chronic intestinal inflammation with accumulation of granulocytes and CD4+ T cells. This phenotype was associated with cytoskeleton rearrangement and aberrant cell shedding ultimately leading to loss of epithelial integrity and subsequent inflammation. These findings uncover deficient prenylation of Rho-A as a key player in the pathogenesis of IBD. As therapeutic triggering of Rho-A signaling suppressed intestinal inflammation in mice with GGTase-I deficient IECs, our findings open new avenues for treatment of epithelial injury and mucosal inflammation in IBD patients
Simulating galaxy Clusters -II: global star formation histories and galaxy populations
Cosmological (LambdaCDM) TreeSPH simulations of the formation and evolution
of galaxy groups and clusters have been performed. The simulations invoke star
formation, chemical evolution with non-instantaneous recycling, metal dependent
radiative cooling, strong star burst and (optionally) AGN driven galactic super
winds, effects of a meta-galactic UV field and thermal conduction. The
properties of the galaxy populations in two clusters, one Virgo-like (T~3 keV)
and one (sub) Coma-like (T~6 keV), are discussed. The global star formation
rates of the cluster galaxies are found to decrease very significantly with
time from redshift z=2 to 0, in agreement with observations. The total K-band
luminosity of the cluster galaxies correlates tightly with total cluster mass,
and for models without additional AGN feedback, the zero point of the relation
matches the observed one fairly well. The match to observed galaxy luminosity
functions is reasonable, except for a deficiency of bright galaxies (M_B <
-20), which becomes increasingly significant with super-wind strength. Results
of a high resolution test indicate that this deficiency is not due to
``over--merging''. The redshift evolution of the luminosity functions from z=1
to 0 is mainly driven by luminosity evolution, but also by merging of bright
galaxies with the cD. The colour--magnitude relation of the cluster galaxies
matches the observed "red sequence" very well and, on average, galaxy
metallicity increases with luminosity. As the brighter galaxies are essentially
coeval, the colour--magnitude relation results from metallicity rather than age
effects, as observed.Comment: 15 pages, 10 figures. Final version accepted by MNRAS, presenting new
simulations and major changes. Printing in colour recommende
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