45,885 research outputs found
Future Trends of Virtual, Augmented Reality, and Games for Health
Serious game is now a multi-billion dollar industry and is still growing steadily in many sectors. As a major subset of serious games, designing and developing Virtual Reality (VR), Augmented Reality (AR), and serious games or adopting off-the-shelf games to support medical education, rehabilitation, or promote health has become a promising frontier in the healthcare sector since 2004, because games technology is inexpensive, widely available, fun and entertaining for people of all ages, with various health conditions and different sensory, motor, and cognitive capabilities. In this chapter, we provide the reader an overview of the book with a perspective of future trends of VR, AR simulation and serious games for healthcare
Reduced chromosome aberration complexity in normal human bronchial epithelial cells exposed to low-LET γ-rays and high-LET α-particles
This article is made available through the Brunel Open Access Publishing Fund.Copyright © 2013 The Author(s). Purpose: Cells of the lung are at risk from exposure to low and moderate doses of ionizing radiation from a range of environmental and medical sources. To help assess human health risks from such exposures, a better understanding of the frequency and types of chromosome aberration initially-induced in human lung cell types is required to link initial DNA damage and rearrangements with transmission potential and, to assess how this varies with radiation quality.
Materials and methods: We exposed normal human bronchial lung epithelial (NHBE) cells in vitro to 0.5 and 1 Gy low-linear energy transfer (LET) γ-rays and a low fluence of high-LET α-particles and assayed for chromosome aberrations in premature chromosome condensation (PCC) spreads by 24-color multiplex-fluorescence in situ hybridization (M-FISH).
Results: Both simple and complex aberrations were induced in a LET and dose-dependent manner; however, the frequency and complexity observed were reduced in comparison to that previously reported in spherical cell types after exposure to comparable doses or fluence of radiation. Approximately 1–2% of all exposed cells were categorized as being capable of transmitting radiation-induced chromosomal damage to future NHBE cell generations, irrespective of dose.
Conclusion: One possible mechanistic explanation for this reduced complexity is the differing geometric organization of chromosome territories within ellipsoid nuclei compared to spherical nuclei. This study highlights the need to better understand the role of nuclear organization in the formation of exchange aberrations and, the influence three-dimensional (3D) tissue architecture may have on this in vivo.Department of Health, UK (Contract RRX115)
Spread of Infectious Diseases with a Latent Period
Infectious diseases spread through human networks.
Susceptible-Infected-Removed (SIR) model is one of the epidemic models to
describe infection dynamics on a complex network connecting individuals. In the
metapopulation SIR model, each node represents a population (group) which has
many individuals. In this paper, we propose a modified metapopulation SIR model
in which a latent period is taken into account. We call it SIIR model. We
divide the infection period into two stages: an infected stage, which is the
same as the previous model, and a seriously ill stage, in which individuals are
infected and cannot move to the other populations. The two infectious stages in
our modified metapopulation SIR model produce a discontinuous final size
distribution. Individuals in the infected stage spread the disease like
individuals in the seriously ill stage and never recover directly, which makes
an effective recovery rate smaller than the given recovery rate.Comment: 6 pages, 3 figure
Effect of linear energy transfer (LET) on complexity of alpha-particle-induced chromosome aberrations in human CD34+ cells.
The aim of this study was to assess the relative influence of linear energy transfer (LET) of α-particles on chromosome aberration complexity in the absence of significant other track structure differences. To do this we irradiated human haemopoietic stem cells (CD34+) with The aim of this study was to assess the relative influence of linear energy transfer (LET) of α-particles of various incident LET values (110 - 152 keV/µm, with mean LETs through the cell of 119 – 182 keV/µm) at an equi-fluence of approximately 1 α-particle/cell and assayed for chromosome aberrations by m-FISH. Based on a single harvest time to collect early division mitosis , complex aberrations were observed at comparable frequencies irrespective of incident LET, however when expressed as a proportion of the total exchanges detected, their occurrence was seen to increase with increasing LET. Cycle analysis to predict theoretical DNA double strand break rejoining cycles was also carried out on all complex chromosome aberrations detected. By doing this we found that the majority of complex aberrations are formed in single non-reducible cycles that involve just 2 or 3 different chromosomes and 3 or 4 different breaks. Each non-reducible cycle is suggested to represent ‘an area’ of finite size within the nucleus where double strand break repair occurs. We suggest that local density of damage induced and proximity of independent repair areas within the interphase nucleus determine the complexity of aberration resolved in metaphase. Overall, the most likely outcome of a single nuclear traversal of a single α-particle in CD34+ cells is a single chromosome aberration per damaged cell. As the incident LET of the α-particle increases, the likelihood of this aberration being classed as complex is greater
Interplay between single particle coherence and kinetic energy driven superconductivity in doped cuprates
Within the kinetic energy driven superconducting mechanism, the interplay
between the single particle coherence and superconducting instability in doped
cuprates is studied. The superconducting transition temperature increases with
increasing doping in the underdoped regime, and reaches a maximum in the
optimal doping, then decreases in the overdoped regime, however, the values of
this superconducting transition temperature in the whole superconducting range
are suppressed to low temperature due to the single particle coherence. Within
this superconducting mechanism, we calculate the dynamical spin structure
factor of cuprate superconductors, and reproduce all main features of inelastic
neutron scattering experiments in the superconducting-state.Comment: 7 pages, 3 figures, typo correcte
Quarter-Flux Hofstadter Lattice in Qubit-Compatible Microwave Cavity Array
Topological- and strongly-correlated- materials are exciting frontiers in
condensed matter physics, married prominently in studies of the fractional
quantum hall effect [1]. There is an active effort to develop synthetic
materials where the microscopic dynamics and ordering arising from the
interplay of topology and interaction may be directly explored. In this work we
demonstrate a novel architecture for exploration of topological matter
constructed from tunnel-coupled, time-reversalbroken microwave cavities that
are both low loss and compatible with Josephson junction-mediated interactions
[2]. Following our proposed protocol [3] we implement a square lattice
Hofstadter model at a quarter flux per plaquette ({\alpha} = 1/4), with
time-reversal symmetry broken through the chiral Wannier-orbital of resonators
coupled to Yttrium-Iron-Garnet spheres. We demonstrate site-resolved
spectroscopy of the lattice, time-resolved dynamics of its edge channels, and a
direct measurement of the dispersion of the edge channels. Finally, we
demonstrate the flexibility of the approach by erecting a tunnel barrier
investigating dynamics across it. With the introduction of Josephson-junctions
to mediate interactions between photons, this platform is poised to explore
strongly correlated topological quantum science for the first time in a
synthetic system.Comment: 11 pages, 9 Figure
Cognitive architectures as Lakatosian research programmes: two case studies
Cognitive architectures - task-general theories of the structure and function of the complete cognitive system - are sometimes argued to be more akin to frameworks or belief systems than scientific theories. The argument stems from the apparent non-falsifiability of existing cognitive architectures. Newell was aware of this criticism and argued that architectures should be viewed not as theories subject to Popperian falsification, but rather as Lakatosian research programs based on cumulative growth. Newell's argument is undermined because he failed to demonstrate that the development of Soar, his own candidate architecture, adhered to Lakatosian principles. This paper presents detailed case studies of the development of two cognitive architectures, Soar and ACT-R, from a Lakatosian perspective. It is demonstrated that both are broadly Lakatosian, but that in both cases there have been theoretical progressions that, according to Lakatosian criteria, are pseudo-scientific. Thus, Newell's defense of Soar as a scientific rather than pseudo-scientific theory is not supported in practice. The ACT series of architectures has fewer pseudo-scientific progressions than Soar, but it too is vulnerable to accusations of pseudo-science. From this analysis, it is argued that successive versions of theories of the human cognitive architecture must explicitly address five questions to maintain scientific credibility
Electronic structure of the electron-doped cuprate superconductors
Within the framework of the kinetic energy driven d-wave superconductivity,
the electronic structure of the electron doped cuprate superconductors is
studied. It is shown that although there is an electron-hole asymmetry in the
phase diagram, the electronic structure of the electron-doped cuprates in the
superconducting-state is similar to that in the hole-doped case. With
increasing the electron doping, the spectral weight in the point
increases, while the position of the superconducting quasiparticle peak is
shifted towards the Fermi energy. In analogy to the hole-doped case, the
superconducting quasiparticles around the point disperse very weakly
with momentum.Comment: 8 pages, 3 figures, accepted for publication in Phys. Lett.
Enhancement of superconducting transition temperature by the additional second neighbor hopping t' in the t-J model
Within the kinetic energy driven superconducting mechanism, the effect of the
additional second neighbor hopping t' on the superconducting state of the t-J
model is discussed. It is shown that t' plays an important role in enhancing
the superconducting transition temperature of the t-J model. It is also shown
that the superconducting-state of cuprate superconductors is the conventional
Bardeen-Cooper-Schrieffer like, so that the basic Bardeen-Cooper-Schrieffer
formalism is still valid in quantitatively reproducing the doping dependence of
the superconducting gap parameter and superconducting transition temperature,
and electron spectral function at point, although the pairing
mechanism is driven by the kinetic energy by exchanging dressed spin
excitations.Comment: 8 pages, 4 figures, added discussions and references, accepted for
publication in Physics Letters
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