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The effect of pitch span on intonational plateaux
Previous research has indicated that the H (high) of a nuclear accent may be realized as a flat stretch of contour rather than as a single turning point. Both the duration of this plateau and its alignment within the accented syllable are affected by the segmental and prosodic structure of the utterance. The present work investigates whether a non-structural variable, namely pitch span, also affects the realization of the plateau. Speakers replicated all-sonorant utterances in different pitch spans. Results show that both the duration and alignment of the plateau vary with pitch span but in ways different from the way they vary with prosodic structure. Importantly, results also indicate that, when using a proportional measure of alignment, the end of the plateau is anchored within the syllable for each speaker and may be a marker of linguistic structure
Glycosylphosphatidylinositols: More than just an anchor?
There is increasing interest in the role of glycosylphosphatidylinositol (GPI) anchors that attach some proteins to cell membranes. Far from being biologically inert, GPIs influence the targeting, intracellular trafficking and function of the attached protein. Our recent paper demonstrated the role of sialic acid on the GPI of the cellular prion protein (PrPC). The “prion diseases” arise following the conversion of PrPC to a disease-associated isoform called PrPSc or “prion”. Our paper showed that desialylated PrPC inhibited PrPSc formation. Aggregated PrPSc creates a signaling platform in the cell membrane incorporating and activating cytoplasmic phospholipase A2 (cPLA2), an enzyme that regulates PrPC trafficking and hence PrPSc formation. The presence of desialylated PrPC caused the dissociation of cPLA2 from PrP-containing platforms, reduced the activation of cPLA2 and inhibited PrPSc production. We concluded that sialic acid contained within the GPI attached to PrPC modifies local membrane microenvironments that are important in PrP-mediated cell signaling and PrPSc formation
Finding Young Stellar Populations in Elliptical Galaxies from Independent Components of Optical Spectra
Elliptical galaxies are believed to consist of a single population of old
stars formed together at an early epoch in the Universe, yet recent analyses of
galaxy spectra seem to indicate the presence of significant younger populations
of stars in them. The detailed physical modelling of such populations is
computationally expensive, inhibiting the detailed analysis of the several
million galaxy spectra becoming available over the next few years. Here we
present a data mining application aimed at decomposing the spectra of
elliptical galaxies into several coeval stellar populations, without the use of
detailed physical models. This is achieved by performing a linear independent
basis transformation that essentially decouples the initial problem of joint
processing of a set of correlated spectral measurements into that of the
independent processing of a small set of prototypical spectra. Two methods are
investigated: (1) A fast projection approach is derived by exploiting the
correlation structure of neighboring wavelength bins within the spectral data.
(2) A factorisation method that takes advantage of the positivity of the
spectra is also investigated. The preliminary results show that typical
features observed in stellar population spectra of different evolutionary
histories can be convincingly disentangled by these methods, despite the
absence of input physics. The success of this basis transformation analysis in
recovering physically interpretable representations indicates that this
technique is a potentially powerful tool for astronomical data mining.Comment: 12 Pages, 7 figures; accepted in SIAM 2005 International Conference
on Data Mining, Newport Beach, CA, April 200
Environmental Enforcement and the Limits of Cooperative Federalism: Will Courts Allow Citizen Suits to Pick Up the Slack
Relative Income, Redistribution and Well-being
In a model with heterogeneous workers and both intensive and extensive margins of employment, we consider two systems of redistribution: a universal basic income, and a categorical unemployment benefit. Well-being depends on own-consumption relative to average employed workers’ consumption, and concern for relativity is a parameter that affects model outcomes. While labour supply incurs positive marginal disutility, we allow negative welfare effects of unemployment. We also compare Rawlsian and utilitarian welfare in general equilibrium under the polar opposite transfer systems, with varying concern for relativity. Basic income Pareto dominates categorical benefits with moderate concern for relativity in both cases.relative income, redistribution, basic income, unemployment benefits, happiness, well-being
Optimal and Robust Quantum Metrology Using Interaction-Based Readouts
Useful quantum metrology requires nonclassical states with a high particle
number and (close to) the optimal exploitation of the state's quantum
correlations. Unfortunately, the single-particle detection resolution demanded
by conventional protocols, such as spin squeezing via one-axis twisting, places
severe limits on the particle number. Additionally, the challenge of finding
optimal measurements (that saturate the quantum Cram{\'e}r-Rao bound) for an
arbitrary nonclassical state limits most metrological protocols to only
moderate levels of quantum enhancement. "Interaction-based readout" protocols
have been shown to allow optimal interferometry \emph{or} to provide robustness
against detection noise at the expense of optimality. In this Letter, we prove
that one has great flexibility in constructing an optimal protocol, thereby
allowing it to also be robust to detection noise. This requires the full
probability distribution of outcomes in an optimal measurement basis, which is
typically easily accessible and can be determined from specific criteria we
provide. Additionally, we quantify the robustness of several classes of
interaction-based readouts under realistic experimental constraints. We
determine that optimal \emph{and} robust quantum metrology is achievable in
current spin-squeezing experiments.Comment: 7 pages, 3 figure
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