5,165 research outputs found
Health chatbots acceptability moderated by perceived stigma and severity: A cross-sectional survey
Background: Chatbots and virtual voice assistants are increasingly common in primary care without sufficient evidence for their feasibility and effectiveness. We aimed to assess how perceived stigma and severity of various health issues are associated with the acceptability for three sources of health information and consultation: an automated chatbot, a General Practitioner (GP), or a combination of both. Methods: Between May and June 2019, we conducted an online study, advertised via Facebook, for UK citizens. It was a factorial simulation experiment with three within-subject factors (perceived health issue stigma, severity, and consultation source) and six between-subject covariates. Acceptability rating for each consultation source was the dependant variable. A single mixed-model ANOVA was performed.
Results: Amongst 237 participants (65% aged over 45 years old, 73% women), GP consultations were seen as most acceptable, followed by GP-chatbot service. Chatbots were seen least acceptable as a consultation source for severe health issues, while the acceptability was significantly higher for stigmatised health issues. No associations between participantsâ characteristics and acceptability were found.
Conclusions: Although healthcare professionals are perceived as the most desired sources of health information, chatbots
may be useful for sensitive health issues in which disclosure of personal information is challenging. However, chatbots
are less acceptable for health issues of higher severity and should not be recommended for use within that context.
Policymakers and digital service designers need to recognise the limitations of health chatbots. Future research should
establish a set of health topics most suitable for chatbot-led interventions and primary healthcare services
Solar dynamic power for Earth orbital and lunar applications
Development of solar dynamic (SD) technologies for space over the past 25 years by NASA Lewis Research Center brought SD power to the point where it was selected in the design phase of Space Station Freedom Program as the power source for evolutionary growth. More recent studies showed that large cost savings are possible in establishing manufacturing processes at a Lunar Base if SD is considered as a power source. Technology efforts over the past 5 years have made possible lighter, more durable, SD components for these applications. A review of these efforts and respective benefits is presented
Accommodation of lattice mismatch in Ge_(x)Si_(1âx)/Si superlattices
We present evidence that the critical thickness for the appearance of misfit defects in a given material and heteroepitaxial structure is not simply a function of lattice mismatch. We report substantial differences in the relaxation of mismatch stress in Ge_(0.5)Si_(0.5)/Si superlattices grown at different temperatures on (100) Si substrates. Samples have been analyzed by xâray diffraction, channeled Rutherford backscattering, and transmission electron microscopy. While a superlattice grown at 365â°C demonstrates a high degree of elastic strain, with a dislocation density <10^5 cm^(â2) , structures grown at higher temperatures show increasing numbers of structural defects, with densities reaching 2Ă10^(10) cm^(â2) at a growth temperature of 530â°C. Our results suggest that it is possible to freeze a latticeâmismatched structure in a highly strained metastable state. Thus it is not surprising that experimentally observed critical thicknesses are rarely in agreement with those predicted by equilibrium theories
Variational water-wave model with accurate dispersion and vertical vorticity
A new water-wave model has been derived which is based on variational techniques and combines a depth-averaged vertical (component of) vorticity with depth-dependent potential flow. The model facilitates the further restriction of the vertical profile of the velocity potential to n-th order polynomials or a finite-element profile with a small number of elements (say), leading to a framework for efficient modeling of the interaction of steepening and breaking waves near the shore with a large-scale horizontal flow. The equations are derived from a constrained variational formulation which leads to conservation laws for energy, mass, momentum and vertical vorticity. It is shown that the potential-flow water-wave equations and the shallow-water equations are recovered in the relevant limits. Approximate shock relations are provided, which can be used in numerical schemes to model breaking waves
Square Patterns and Quasi-patterns in Weakly Damped Faraday Waves
Pattern formation in parametric surface waves is studied in the limit of weak
viscous dissipation. A set of quasi-potential equations (QPEs) is introduced
that admits a closed representation in terms of surface variables alone. A
multiscale expansion of the QPEs reveals the importance of triad resonant
interactions, and the saturating effect of the driving force leading to a
gradient amplitude equation. Minimization of the associated Lyapunov function
yields standing wave patterns of square symmetry for capillary waves, and
hexagonal patterns and a sequence of quasi-patterns for mixed capillary-gravity
waves. Numerical integration of the QPEs reveals a quasi-pattern of eight-fold
symmetry in the range of parameters predicted by the multiscale expansion.Comment: RevTeX, 11 pages, 8 figure
Strain relaxation kinetics in Si1âxGex/Si heterostructures
Strain relaxation in Si1âxGex/Si superlattices and alloy films is studied as a function of ex situ anneal treatment with the use of x-ray diffraction and Raman spectroscopy. Samples are grown by molecular-beam epitaxy at an unusually low temperature (â365 °C). This results in metastably strained alloy and superlattice films significantly in excess of critical thicknesses previously reported for such structures. Significant strain relaxation is observed upon anneal at temperatures as low as 390 °C. After a 700 °C, 2 h anneal, superlattices are observed to relax less fully (~43% of coherent strain) than corresponding alloys (~84% of coherent strain). Also, the strain relaxation kinetics of a Si1âxGex alloy layer is studied quantitatively. Alloy strain relaxation is approximately described by a single, thermally activated, first order kinetic process having activation energy Ea=2.0 eV. The relevance of our results to the microscopic mechanisms responsible for strain relaxation in lattice-mismatched semiconductor heterostructures is discussed
Search for exchange-antisymmetric two-photon states
Atomic two-photon J=0 J'=1 transitions are forbidden for
photons of the same energy. This selection rule is related to the fact that
photons obey Bose-Einstein statistics. We have searched for small violations of
this selection rule by studying transitions in atomic Ba. We set a limit on the
probability that photons are in exchange-antisymmetric states:
.Comment: 5 pages, 4 figures, ReVTeX and .eps. Submitted to Phys. Rev. Lett.
Revised version 9/25/9
Toward a Social Practice Theory of Relational Competing
This paper brings together the competitive dynamics and strategy-aspractice literatures to investigate relational competition. Drawing on a global ethnography of the reinsurance market, we develop the concept of micro-competitions, which are the focus of competitorsâ everyday competitive practices. We find variation in relational or rivalrous competition by individual competitors across the phases of a micro-competition, between competitors within a micro-competition, and across multiple micro-competitions. These variations arise from the interplay between the unfolding competitive arena and the implementation of each firmâs strategic portfolio. We develop a conceptual framework that makes four contributions to: relational competition; reconceptualizing action and response; elaborating on the awareness-motivation-capability framework within competitive dynamics; and the recursive dynamic by which implementing strategy inside firms shapes, and is shaped by, the competitive arena
Exploring the psychological rewards of a familiar semirural landscape: connecting to local nature through a mindful approach
This study analyses a 53,000 word diary of a year engaging with nature through over 200 trips to a semi-rural landscape. Thematic analysis revealed two themes; the transition from observer to nature connectedness and the ways in which the natural environment was experienced once a connection was made. These themes are discussed in relation to theories that seek to explain the positive effect of nature and nature connectedness. The findings are important as they suggest that repeated engagement with local semi-rural countryside can lead to a mindful approach and psychological rewards that do not require travel into the wilderness. The work informs further research into outcomes and processes of nature based interventions such as: trip frequency, duration and diary keeping
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