10,268 research outputs found
LEGAL AND INSTITUTIONAL METHODS APPLIED TO ORDERS TO STOP PAYMENT OF CHECKS - II. INSTITUTIONAL METHOD
Rsr1 Palmitoylation and GTPase Activity Status Differentially Coordinate Nuclear, Septin, and Vacuole Dynamics in Candida albicans
Peer reviewedPublisher PD
The Asymmetric Thick Disk: A Star Count and Kinematic Analysis. II The Kinematics
We report a kinematic signature associated with the observed asymmetry in the
distribution of thick disk/inner halo stars interior to the Solar circle
described in Paper I. In that paper we found a statistically significant excess
(20% to 25 %) of stars in quadrant I (l ~ 20 deg to 55 deg) both above and
below the plane (b ~ +/- 25 deg to +/- 45 deg) compared to the complementary
region in quadrant IV. We have measured Doppler velocities for 741 stars,
selected according to the same magnitude and color criteria, in the direction
of the asymmetry and in the corresponding fields in quadrant IV. We have also
determined spectral types and metallicities measured from the same spectra. We
not only find an asymmetric distribution in the V_LSR velocities for the stars
in the two regions, but the angular rate of rotation, w, for the stars in
quadrant I reveals a slower effective rotation rate compared to the
corresponding quadrant IV stars. We use our [Fe/H] measurements to separate the
stars into the three primary population groups, halo, thick disk, and disk, and
conclude that it is primarily the thick disk stars that show the slower
rotation in quadrant I. A solution for the radial, tangential and vertical
components of the V_LSR velocities, reveals a significant lag of ~ 80 to 90
km/s in the direction of Galactic rotation for the thick disk stars in quadrant
I, while in quadrant IV, the same population has only a ~ 20 km/s lag. The
results reported here support a rotational lag among the thick disk stars due
to a gravitational interaction with the bar as the most likely explanation for
the asymmetry in both the star counts and the kinematics. The affected thick
disk stars, however, may be associated with the recently discovered Canis Major
debris stream or a similar merger event (abridged).Comment: Accepted for publication in the Astronomical Journa
Effect of Hydrodynamic Force on Microcantilever Vibrations: Applications to Liquid-Phase Chemical Sensing
At the microscale, cantilever vibrations depend not only on the microstructureâs properties and geometry but also on the properties of the surrounding medium. In fact, when a microcantilever vibrates in a fluid, the fluid offers resistance to the motion of the beam. The study of the influence of the hydrodynamic force on the microcantileverâs vibrational spectrum can be used to either (1) optimize the use of microcantilevers for chemical detection in liquid media or (2) extract the mechanical properties of the fluid. The classical method for application (1) in gas is to operate the microcantilever in the dynamic transverse bending mode for chemical detection. However, the performance of microcantilevers excited in this standard out-of-plane dynamic mode drastically decreases in viscous liquid media. When immersed in liquids, in order to limit the decrease of both the resonant frequency and the quality factor, and improve sensitivity in sensing applications, alternative vibration modes that primarily shear the fluid (rather than involving motion normal to the fluid/beam interface) have been studied and tested: these include in-plane vibration modes (lateral bending mode and elongation mode). For application (2), the classical method to measure the rheological properties of fluids is to use a rheometer. However, such systems require sampling (no in-situ measurements) and a relatively large sample volume (a few milliliters). Moreover, the frequency range is limited to low frequencies (less than 200Hz). To overcome the limitations of this classical method, an alternative method based on the use of silicon microcantilevers is presented. The method, which is based on the use of analytical equations for the hydrodynamic force, permits the measurement of the complex shear modulus of viscoelastic fluids over a wide frequency range
Influence of Fluid-Structure Interaction on Microcantilever Vibrations: Applications to Rheological Fluid Measurement and Chemical Detection
At the microscale, cantilever vibrations depend not only on the microstructureâs properties and geometry but also on the properties of the surrounding medium. In fact, when a microcantilever vibrates in a fluid, the fluid offers resistance to the motion of the beam. The study of the influence of the hydrodynamic force on the microcantileverâs vibrational spectrum can be used to either (1) optimize the use of microcantilevers for chemical detection in liquid media or (2) extract the mechanical properties of the fluid. The classical method for application (1) in gas is to operate the microcantilever in the dynamic transverse bending mode for chemical detection. However, the performance of microcantilevers excited in this standard out-of-plane dynamic mode drastically decreases in viscous liquid media. When immersed in liquids, in order to limit the decrease of both the resonant frequency and the quality factor, alternative vibration modes that primarily shear the fluid (rather than involving motion normal to the fluid/beam interface) have been studied and tested: these include inplane vibration modes (lateral bending mode and elongation mode). For application (2), the classical method to measure the rheological properties of fluids is to use a rheometer. To overcome the limitations of this classical method, an alternative method based on the use of silicon microcantilevers is presented. The method, which is based on the use of analytical equations for the hydrodynamic force, permits the measurement of the complex shear modulus of viscoelastic fluids over a wide frequency range
Effect of Aqueous Ozone on the NF-ÎșB System
Ozone has been proposed as an alternative oral antiseptic in dentistry, due to its antimicrobial power reported for gaseous and aqueous forms, the latter showing a high biocompatibility with mammalian cells. New therapeutic strategies for the treatment of periodontal disease and apical periodontitis should consider not only antibacterial effects, but also their influence on the host immune response. Therefore, our aim was to investigate the effect of aqueous ozone on the NF-ÎșB system, a paradigm for inflammationassociated signaling/transcription. We showed that NF-ÎșB activity in oral cells stimulated with TNF, and in periodontal ligament tissue from root surfaces of periodontally damaged teeth, was inhibited following incubation with ozonized medium. Under this treatment, IÎșBalpah proteolysis, cytokine expression, and ÎșB-dependent transcription were prevented. Specific ozonized amino acids were shown to represent major inhibitory components of ozonized medium. In summary, our study establishes a condition under which aqueous ozone exerts inhibitory effects on the NF-ÎșB system, suggesting that it has an antiinflammatory capacity
The ELAN Environment: a Rewriting Logic Environment based on ASF+SDF TechnologyâSystem Demonstrationâ
Phase instabilities in hexagonal patterns
The general form of the amplitude equations for a hexagonal pattern including
spatial terms is discussed. At the lowest order we obtain the phase equation
for such patterns. The general expression of the diffusion coefficients is
given and the contributions of the new spatial terms are analysed in this
paper. From these coefficients the phase stability regions in a hexagonal
pattern are determined. In the case of Benard-Marangoni instability our results
agree qualitatively with numerical simulations performed recently.Comment: 6 pages, 6 figures, to appear in Europhys. Let
Amplitude equations for a system with thermohaline convection
The multiple scale expansion method is used to derive amplitude equations for
a system with thermohaline convection in the neighborhood of Hopf and Taylor
bifurcation points and at the double zero point of the dispersion relation. A
complex Ginzburg-Landau equation, a Newell-Whitehead-type equation, and an
equation of the type, respectively, were obtained. Analytic
expressions for the coefficients of these equations and their various
asymptotic forms are presented. In the case of Hopf bifurcation for low and
high frequencies, the amplitude equation reduces to a perturbed nonlinear
Schr\"odinger equation. In the high-frequency limit, structures of the type of
"dark" solitons are characteristic of the examined physical system.Comment: 21 pages, 8 figure
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