4,487 research outputs found

    A method for automatic detection of tongued and slurred note transitions in clarinet playing

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    This study offers a simple method to characterize two transition types in passages of music in order to automatically distinguish slurred transitions from tongued transitions in musical settings. Data were recorded from musicians playing a clarinet with a sensor-equipped mouthpiece measuring blowing pressure in the mouth and pressure in the mouthpiece. This method allows for comparing transitions in different musical contexts, playing regimes, and between players. The method is highly reliable in automatically detecting transition types in recorded clarinet playing in both simple and more complex passages

    Contracture of the Infraspinatus Muscle in the Dog

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    A tentative diagnosis of contracture of the infraspinatus muscle was made in a dog with a foreleg shoulder lameness causing a positional deformity and characteristic abnormal gait in the affected limb. Contracture of the infraspinatus muscle most commonly involves hunting breeds, particularly actively working dogs

    Mid-Infrared Variability of protostars in IC 1396A

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    We have used Spitzer/IRAC to conduct a photometric monitoring program of the IC1396A dark globule in order to study the mid-IR (3.6 - 8 micron) variability of the heavily embedded Young Stellar Objects (YSOs) present in that area. We obtained light curves covering a 14 day timespan with a twice daily cadence for 69 YSOs, and continuous light curves with approximately 12 second cadence over 7 hours for 38 YSOs. Typical accuracies for our relative photometry were 1-2% for the long timespan data and a few mmag, corresponding to less than 0.5%, for the 7 hour continuous "staring-mode" data. More than half of the YSOs showed detectable variability, with amplitudes from ~0.05 mag to ~0.2 mag. About thirty percent of the YSOs showed quasi-sinusoidal light curve shapes with apparent periods from 5-12 days and light curve amplitudes approximately independent of wavelength over the IRAC bandpasses. We have constructed models which simulate the time dependent spectral energy distributions of Class I and I I YSOs in order to attempt to explain these light curves. Based on these models, the apparently periodic light curves are best explained by YSO models where one or two high latitude photospheric spots heat the inner wall of the circumstellar disk, and where we view the disk at fairly large inclination angle. Disk inhomogeneities, such as increasing the height where the accretion funnel flows to the stellar hotspot, enhances the light curve modulations. The other YSOs in our sample show a range of light curve shapes, some of which are probably due to varying accretion rate or disk shadowing events. One star, IC1396A-47, shows a 3.5 hour periodic light curve; this object may be a PMS Delta Scuti star

    NIRT: Developing a Nanoscale Sensing Device for Measuring the Supply of Iron to Phytoplankton in Marine Systems

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    There is increasing evidence that Fe has a singularly unique role in marine ecosystems, both regulating total phytoplankton production in high nitrate, low chlorophyll regions of the world, and influencing the predominant composition of the phytoplankton assemblages found in others. It is remarkable then that there is no agreement about how to define biologically available Fe, in contrast to the macronutrients nitrogen, phosphorous or silicon. Current attempts to attain predictive insights to how ocean ecosystems will influence the magnitude of climate change are blocked in large part by this question, along with an extreme shortage of data on Fe distributions in the oceans. There is recent evidence that Fe availability can be regulated in bulk seawater incubations by small additions of the fungal siderophore desferrioximine B (DFB). The Fe-DFB complex is not readily available to eukaryotic phytoplankton, so that if the quantity of Fe complexed by DFB were measured and calibrated to Fe uptake by phytoplankton it could yield a novel first order measure of Fe availability. Building from our current research we have developed liposomes that specifically acquire DFB-bound Fe from solution. These devices, 100 nm in diameter, open the way to applying nanotechnology to create a new breed of Fe biosensors in marine waters. The project goals are to 1) optimize these nanodevices by improving their physical robustness, identifying the size/functionality relationship, and examining the efficacy of other DFB-Fe transporter molecules, 2) develop self-reporting capabilities for quantifying Fe uptake by these nanodevices, and 3) to calibrate the capture of Fe by these nanodevices to the Fe uptake by various phytoplankton species. The anticipated final product will be a calibrated nanoscale biosensor for laboratory-scale use that could then be adapted for deploying on remote vehicles. Broader Impacts Resulting from the Proposed Activity: The two institutions involved in this project (U. Maine and Colby College) have a strong track record for involving undergraduate and graduate students in cutting edge research in marine science and chemistry, and this project will continue this process

    Semiclassical Theory of Quantum Chaotic Transport: Phase-Space Splitting, Coherent Backscattering and Weak Localization

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    We investigate transport properties of quantized chaotic systems in the short wavelength limit. We focus on non-coherent quantities such as the Drude conductance, its sample-to-sample fluctuations, shot-noise and the transmission spectrum, as well as coherent effects such as weak localization. We show how these properties are influenced by the emergence of the Ehrenfest time scale \tE. Expressed in an optimal phase-space basis, the scattering matrix acquires a block-diagonal form as \tE increases, reflecting the splitting of the system into two cavities in parallel, a classical deterministic cavity (with all transmission eigenvalues either 0 or 1) and a quantum mechanical stochastic cavity. This results in the suppression of the Fano factor for shot-noise and the deviation of sample-to-sample conductance fluctuations from their universal value. We further present a semiclassical theory for weak localization which captures non-ergodic phase-space structures and preserves the unitarity of the theory. Contrarily to our previous claim [Phys. Rev. Lett. 94, 116801 (2005)], we find that the leading off-diagonal contribution to the conductance leads to the exponential suppression of the coherent backscattering peak and of weak localization at finite \tE. This latter finding is substantiated by numerical magnetoconductance calculations.Comment: Typos in central eqns corrected (this paper supersedes cond-mat/0509186) 20page

    Changes in Georgia Restaurant and Bar Smoking Policies From 2006 to 2012

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    Introduction The purpose of this study is to examine the change in smoking policy status among Georgia restaurants and bars from 2006 to 2012 and to identify restaurant and bar characteristics that are as- sociated with allowing smoking. Methods Data were obtained from similar cross-sectional indoor air sur- veys conducted in 2006 and 2012 in Georgia. Both surveys were designed to gather information about restaurant and bar smoking policies. Weighted χ2 analyses were performed to identify changes in smoking policy status and other variables from 2006 to 2012. Weighted logistic regression analysis was used to test for signific- ant associations between an establishment’s smoking policy and other characteristics. Results The percentage of restaurants and bars in Georgia that allowed smoking nearly doubled, from 9.1% in 2006 to 17.6% in 2012. The analyses also showed a significant increase in the percentage of establishments that allow smoking when minors are present. Having a liquor license was a significant predictor of allowing smoking. Conclusion The Smokefree Air Act was enacted in 2005 to protect the health and welfare of Georgia citizens, but study results suggest that policy makers should reevaluate the law and consider strengthening it to make restaurants and bars 100% smokefree without exemptions

    The origin of mid-infrared emission in massive young stellar objects: multi-baseline VLTI observations of W33A

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    The circumstellar structure on 100 AU scales of the massive young stellar object W33A is probed using the VLTI and the MIDI instrument. N-band visibilities on 4 baselines are presented which are inconsistent with a spherically symmetric geometry. The visibility spectra and SED are simultaneously compared to 2D axi-symmetric dust radiative transfer models with a geometry including a rotationally flattened envelope and outflow cavities. We assume an O7.5 ZAMS star as the central source, consistent with the observed bolometric luminosity. The observations are also compared to models with and without (dusty and gaseous) accretion disks. A satisfactory model is constructed which reproduces the visibility spectra for each (u,v) point. It fits the silicate absorption, the mid-IR slope, the far-infrared peak, and the (sub)mm of the SED. It produces a 350 micron morphology consistent with observations. The 10 micron emission on 100 AU scales is dominated by the irradiated walls of the cavity sculpted by the outflow. The visibilities rule out the presence of dust disks with total (gas and dust) masses more than 0.01 Msun. However, optically thick accretion disks, interior to the dust sublimation radius, are allowed to accrete at rates equalling the envelope's mass infall rate (up to 10^(-3) Msun/yr) without substantially affecting the visibilities due to the extinction by the extremely massive envelope of W33A.Comment: Accepted for publication in A&

    Tools in the orbit space approach to the study of invariant functions: rational parametrization of strata

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    Functions which are equivariant or invariant under the transformations of a compact linear group GG acting in an euclidean space n\real^n, can profitably be studied as functions defined in the orbit space of the group. The orbit space is the union of a finite set of strata, which are semialgebraic manifolds formed by the GG-orbits with the same orbit-type. In this paper we provide a simple recipe to obtain rational parametrizations of the strata. Our results can be easily exploited, in many physical contexts where the study of equivariant or invariant functions is important, for instance in the determination of patterns of spontaneous symmetry breaking, in the analysis of phase spaces and structural phase transitions (Landau theory), in equivariant bifurcation theory, in crystal field theory and in most areas where use is made of symmetry adapted functions. A physically significant example of utilization of the recipe is given, related to spontaneous polarization in chiral biaxial liquid crystals, where the advantages with respect to previous heuristic approaches are shown.Comment: Figures generated through texdraw package; revised version appearing in J. Phys. A: Math. Ge
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