328 research outputs found
The real deal: Interrogating the paradoxical co-existence of reality and construction in contemporary theatre
Through a practice led approach, this study investigates how the constituent elements of theatre can be calibrated to disrupt perceptions of reality within the theatre event. A 'System of Calibration' was devised to enable theatre makers to regulate theatre phenomena and articulate the relationship between construct and reality in contemporary Postdramatic performance. The system can be used as a proactive tool for dramaturgical analysis of performance in creation and a retroactive tool for the deconstruction of existing works
The Role of Entrepreneur-Venture Fit in Online Home-based Entrepreneurship: A Systematic Literature Review
Home-based businesses and their founders represent an important, but under-researched facet of entrepreneurship. Far from being small, hobby-businesses with little economic impact, home-based business make significant contribution to national economies in terms of both turnover and employment. Online home-based businesses have been recognised as an important and distinct sector of the home-based business domain, offering unique opportunity for innovation and business diversity. The paper presents a systematic literature review of extant research on online home-based entrepreneurs and their businesses. The findings of the review are structured and discussed using the theoretical lens of entrepreneur-venture fit. Use of this lens allows the study to bring coherence to previously fragmented extant studies, providing a basis for future research in this domain. The study also develops a novel model of entrepreneur-venture fit in the specific case of online home-based businesses. This allows us to suggest five positive interactions between entrepreneurial and venture characteristics. It also allows us to suggest a number of previously unidentified negative interactions, which may result in entrepreneurs becoming ‘locked-in’ and suffering multiple sources of stress
Regular modes in rotating stars
Despite more and more observational data, stellar acoustic oscillation modes
are not well understood as soon as rotation cannot be treated perturbatively.
In a way similar to semiclassical theory in quantum physics, we use acoustic
ray dynamics to build an asymptotic theory for the subset of regular modes
which are the easiest to observe and identify. Comparisons with 2D numerical
simulations of oscillations in polytropic stars show that both the frequency
and amplitude distributions of these modes can accurately be described by an
asymptotic theory for almost all rotation rates. The spectra are mainly
characterized by two quantum numbers; their extraction from observed spectra
should enable one to obtain information about stellar interiors.Comment: 5 pages, 4 figures, discussion adde
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Geographic Life History Differences Predict Genomic Divergence Better than Mitochondrial Barcodes or Phenotype
Species diversity can be inferred using multiple data types, however, results based on genetic data can be at odds with patterns of phenotypic variation. Tiger beetles of the Cicindelidia politula (LeConte, 1875) species complex have been taxonomically problematic due to extreme phenotypic variation within and between populations. To better understand the biology and taxonomy of this group, we used mtDNA genealogies and multilocus nuclear analyses of 34,921 SNPs to elucidate its evolutionary history and evaluate the validity of phenotypically circumscribed species and subspecies. Genetic analyses recovered two divergent species that are also ecologically distinct, based on adult life history. These patterns are incongruous with the phenotypic variation that informed prior taxonomy, and most subspecies were not supported as distinct evolutionary lineages. One of the nominal subspecies was found to be a cryptic species; consequently, we elevate C. p. laetipennis (Horn, 1913) to a full species. Although nuclear and mtDNA datasets recovered broadly similar evolutionary units, mito-nuclear discordance was more common than expected, being observed between nearly all geographically overlapping taxonomic pairs. Additionally, a pattern of ‘mitochondrial displacement’ was observed, where mitochondria from one species unidirectionally displace others. Overall, we found that geographically associated life history factors better predict genomic divergence than phenotype and mitochondrial genealogies, and consequently taxon identifications based on mtDNA (e.g., DNA barcodes) may be misleading
Cre-dependent DNA recombination activates a STING-dependent innate immune response
Gene-recombinase technologies, such as Cre/loxP-mediated DNA recombination, are important tools in the study of gene function, but have potential side effects due to damaging activity on DNA. Here we show that DNA recombination by Cre instigates a robust antiviral response in mammalian cells, independent of legitimate loxP recombination. This is due to the recruitment of the cytosolic DNA sensor STING, concurrent with Cre-dependent DNA damage and the accumulation of cytoplasmic DNA. Importantly, we establish a direct interplay between this antiviral response and cell-cell interactions, indicating that low cell densities in vitro could be useful to help mitigate these effects of Cre. Taking into account the wide range of interferon stimulated genes that may be induced by the STING pathway, these results have broad implications in fields such as immunology, cancer biology, metabolism and stem cell research. Further, this study sets a precedent in the field of gene-engineering, possibly applicable to other enzymatic-based genome editing technologies
Cre-dependent DNA recombination activates a STING-dependent innate immune response
Gene-recombinase technologies, such as Cre/loxP-mediated DNA recombination, are important tools in the study of gene function, but have potential side effects due to damaging activity on DNA. Here we show that DNA recombination by Cre instigates a robust antiviral response in mammalian cells, independent of legitimate loxP recombination. This is due to the recruitment of the cytosolic DNA sensor STING, concurrent with Cre-dependent DNA damage and the accumulation of cytoplasmic DNA. Importantly, we establish a direct interplay between this antiviral response and cell-cell interactions, indicating that low cell densities in vitro could be useful to help mitigate these effects of Cre. Taking into account the wide range of interferon stimulated genes that may be induced by the STING pathway, these results have broad implications in fields such as immunology, cancer biology, metabolism and stem cell research. Further, this study sets a precedent in the field of gene-engineering, possibly applicable to other enzymatic-based genome editing technologies
Insights into the influence of solvent polarity on the crystallization of poly(ethylene oxide) spin-coated thin films via in situ grazing incidence wide-angle X-ray scattering
Controlling polymer thin-film morphology and crystallinity is crucial for a wide range of applications, particularly in thin-film organic electronic devices. In this work, the crystallization behavior of a model polymer, poly(ethylene oxide) (PEO), during spin-coating is studied. PEO films were spun-cast from solvents possessing different polarities (chloroform, THF, and methanol) and probed via in situ grazing incidence wide-angle X-ray scattering. The crystallization behavior was found to follow the solvent polarity order (where chloroform chloroform > methanol). When spun-cast from nonpolar chloroform, crystallization largely followed Avrami kinetics, resulting in the formation of morphologies comprising large spherulites. PEO solutions cast from more polar solvents (THF and methanol) do not form well-defined highly crystalline morphologies and are largely amorphous with the presence of small crystalline regions. The difference in morphological development of PEO spun-cast from polar solvents is attributed to clustering phenomena that inhibit polymer crystallization. This work highlights the importance of considering individual components of polymer solubility, rather than simple total solubility, when designing processing routes for the generation of morphologies with optimum crystallinities or morphologies
Dynamical decoupling of unbounded Hamiltonians
We investigate the possibility to suppress interactions between a finite
dimensional system and an infinite dimensional environment through a fast
sequence of unitary kicks on the finite dimensional system. This method, called
dynamical decoupling, is known to work for bounded interactions, but physical
environments such as bosonic heat baths are usually modelled with unbounded
interactions, whence here we initiate a systematic study of dynamical
decoupling for unbounded operators. We develop a sufficient decoupling
criterion for arbitrary Hamiltonians and a necessary decoupling criterion for
semibounded Hamiltonians. We give examples for unbounded Hamiltonians where
decoupling works and the limiting evolution as well as the convergence speed
can be explicitly computed. We show that decoupling does not always work for
unbounded interactions and provide both physically and mathematically motivated
examples.Comment: 18 pages, 3 figure
Asteroseismology of the open clusters NGC 6791, NGC 6811, and NGC 6819 from nineteen months of Kepler photometry
We studied solar-like oscillations in 115 red giants in the three open
clusters NGC 6791, NGC 6811, and NGC 6819, based on photometric data covering
more than 19 months with NASA's Kepler space telescope. We present the
asteroseismic diagrams of the asymptotic parameters \delta\nu_02, \delta\nu_01
and \epsilon, which show clear correlation with fundamental stellar parameters
such as mass and radius. When the stellar populations from the clusters are
compared, we see evidence for a difference in mass of the red giant branch
stars, and possibly a difference in structure of the red clump stars, from our
measurements of the small separations \delta\nu_02 and \delta\nu_01. Ensemble
\'{e}chelle diagrams and upper limits to the linewidths of l = 0 modes as a
function of \Delta\nu of the clusters NGC 6791 and NGC 6819 are also shown,
together with the correlation between the l = 0 ridge width and the T_eff of
the stars. Lastly, we distinguish between red giant branch and red clump stars
through the measurement of the period spacing of mixed dipole modes in 53 stars
among all the three clusters to verify the stellar classification from the
color-magnitude diagram. These seismic results also allow us to identify a
number of special cases, including evolved blue stragglers and binaries, as
well as stars in late He-core burning phases, which can be potentially
interesting targets for detailed theoretical modeling.Comment: 30 pages, 15 figures, 1 table, accepted to Ap
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