8,483 research outputs found

    Elimination of redundancy in telemetered data

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    Procedure for estimating the intensity of a Poisson process can be readily programmed for a digital computer, and does not require an a priori probability space. Reduction of the sampling rate is possible without sacrificing significant information

    Car Racing Game

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    This project is a racing and car collecting video game, which can be played by one or more players. A player can buy cars, upgrade owned cars, tune owned cars, and use owned cars to race for money to buy, upgrade, and tune cars. The game runs on a personal computer in a Windows environment and can be played with keyboard, mouse, or a joystick. It can also be ported to other platforms such as Android or iOS. It was developed using Unity3D 5.4 Game Engine and features 3D graphic and physic simulation

    Understanding the role of chromatin remodeling in the regulation of circadian transcription in Drosophila.

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    Circadian clocks enable organisms to anticipate daily changes in the environment and coordinate temporal rhythms in physiology and behavior with the 24-h day-night cycle. The robust cycling of circadian gene expression is critical for proper timekeeping, and is regulated by transcription factor binding, RNA polymerase II (RNAPII) recruitment and elongation, and post-transcriptional mechanisms. Recently, it has become clear that dynamic alterations in chromatin landscape at the level of histone posttranslational modification and nucleosome density facilitate rhythms in transcription factor recruitment and RNAPII activity, and are essential for progression through activating and repressive phases of circadian transcription. Here, we discuss the characterization of the BRAHMA (BRM) chromatin-remodeling protein in Drosophila in the context of circadian clock regulation. By dissecting its catalytic vs. non-catalytic activities, we propose a model in which the non-catalytic activity of BRM functions to recruit repressive factors to limit the transcriptional output of CLOCK (CLK) during the active phase of circadian transcription, while the primary function of the ATP-dependent catalytic activity is to tune and prevent over-recruitment of negative regulators by increasing nucleosome density. Finally, we divulge ongoing efforts and investigative directions toward a deeper mechanistic understanding of transcriptional regulation of circadian gene expression at the chromatin level

    Color dipole cross section and inelastic structure function

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    Instead of starting from a theoretically motivated form of the color dipole cross section in the dipole picture of deep inelastic scattering, we start with a parametrization of the deep inelastic structure function for electromagnetic scattering with protons, and then extract the color dipole cross section. Using the parametrizations of F2(ξ=x or W2,Q2)F_2(\xi=x \ {\rm or}\ W^2,Q^2) by Donnachie-Landshoff and Block et al., we find the dipole cross section from an approximate form of the presumed dipole cross section convoluted with the perturbative photon wave function for virtual photon splitting into a color dipole with massless quarks. The color dipole cross section determined this way reproduces the original structure function within about 10\% for 0.10.1 GeV2Q210^2\leq Q^2\leq 10 GeV2^2. We discuss the large and small form of the dipole cross section and compare with other parameterizations.Comment: 11 pages, 12 figure

    Bringing Together Gravity and the Quanta

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    Due to its underlying gauge structure, teleparallel gravity achieves a separation between inertial and gravitational effects. It can, in consequence, describe the isolated gravitational interaction without resorting to the equivalence principle, and is able to provide a tensorial definition for the energy-momentum density of the gravitational field. Considering the conceptual conflict between the local equivalence principle and the nonlocal uncertainty principle, the replacement of general relativity by its teleparallel equivalent can be considered an important step towards a prospective reconciliation between gravitation and quantum mechanics.Comment: 9 pages. Contribution to the proceedings of the Albert Einstein Century International Conference, Paris, 18-22 July, 200

    State of the States 2009

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    Highlights state election results and policy developments in 2008 and projects trends for 2009. Considers how the recession and the new administration's policies may affect states on energy, education, Medicaid, the social safety net, and other issues

    Two-photon spectroscopy of trapped HD+^+ ions in the Lamb-Dicke regime

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    We study the feasibility of nearly-degenerate two-photon rovibrational spectroscopy in ensembles of trapped, sympathetically cooled hydrogen molecular ions using a resonance-enhanced multiphoton dissociation (REMPD) scheme. Taking advantage of quasi-coincidences in the rovibrational spectrum, the excitation lasers are tuned close to an intermediate level to resonantly enhance two-photon absorption. Realistic simulations of the REMPD signal are obtained using a four-level model that takes into account saturation effects, ion trajectories, laser frequency noise and redistribution of population by blackbody radiation. We show that the use of counterpropagating laser beams enables optical excitation in an effective Lamb-Dicke regime. Sub-Doppler lines having widths in the 100 Hz range can be observed with good signal-to-noise ratio for an optimal choice of laser detunings. Our results indicate the feasibility of molecular spectroscopy at the 101410^{-14} accuracy level for improved tests of molecular QED, a new determination of the proton-to-electron mass ratio, and studies of the time (in)dependence of the latter.Comment: 16 pages, 17 figure

    Phenolic, Carotenoid and Saccharide Compositions of Vietnamese \u3ci\u3eCamellia sinensis\u3c/i\u3e Teas and Herbal Teas

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    Tea (Camellia sinensis) and herbal tea have been recognized as rich sources of bioactive constituents with the ability to exert antioxidant actions. The aims of this study were to analyze phenolic, carotenoid and saccharide contents in a set of Vietnamese tea and herbal tea and compare the results with those of green and black teas marketed in the U.S. In total, 27 phenolics, six carotenoids and chlorophylls, and three saccharides were quantitatively identified. Catechins, quercetin glycosides and chlorogenic acid were the predominating phenolics in the teas, with the concentrations following the order: jasmine/green teas \u3e oolong tea \u3e black tea. Lutein was the dominant carotenoid in the teas and its concentrations were generally found to be higher in the jasmine and green teas than in the oolong and black teas. The study showed that the green teas originating in Vietnam had much higher levels of phenolics and carotenoids than their counterparts stemming from another country. The application of partial least squares discriminant analysis (PLS-DA) as a chemometric tool was able to differentiate phenolic profiles between methanolic extracts and tea infusions. Through principal component analysis (PCA), the similarities and dissimilarities among the jasmine, green, oolong, black teas and herbal teas were depicted

    Internal generation of waves with damping using extended Boussinesq equations

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    It has been known that the waves generated internally propagate with the energy velocity (Lee and Suh 1998; Lee et al. 2001). Until now, this internal wave generation technique has been developed for waves without damping. In real sea, waves may experience energy dissipation when passing through porous media or in surf zone. In this study, we develop techniques of internal generation of waves with damping using the extended Boussinesq equations of Nwogu (1993). Using the Green's function method (Wei et al. 1999), we derive the Gaussian-shaped source functions. Through numerical experiments for linear and nonlinear waves, we find the source functions with damping generate waves accurately
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