Centrifuge mounted motion simulator Patent

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The selection, appraisal and retention of digital scientific data: dighlights of an ERPANET/CODATA workshop

CODATA and ERPANET collaborated to convene an international archiving workshop on the selection, appraisal, and retention of digital scientific data, which was held on 15-17 December 2003 at the Biblioteca Nacional in Lisbon, Portugal. The workshop brought together more than 65 researchers, data and information managers, archivists, and librarians from 13 countries to discuss the issues involved in making critical decisions regarding the long-term preservation of the scientific record. One of the major aims for this workshop was to provide an international forum to exchange information about data archiving policies and practices across different scientific, institutional, and national contexts. Highlights from the workshop discussions are presented

Modified Paschos-Wolfenstein relation and extraction of weak mixing angle sin^2 theta_W

The NuTeV collaboration reported anomalously large weak mixing angle sin^2 theta_W in comparison with the standard model prediction. Neutrino and antineutrino charged- and neutral-current events are analyzed for extracting sin^2 theta_W. Although the Paschos-Wolfenstein relation is not directly used in the analysis, it plays an important role in the determination. Noting that the target nucleus, iron, is not an isoscalar nucleus, we derive a leading-order expression for a modified Paschos-Wolfenstein relation for nuclei, which may have neutron excess. Then, using charge and baryon-number conservations for nuclei, we discuss a nuclear correction in the sin^2 theta_W determination. It is noteworthy that nuclear modifications are different between valence up- and down-quark distributions. We show this difference effect on the NuTeV sin^2 theta_W deviation.Comment: 5 pages, REVTeX4.0, revtex4.cls, url.sty, natbib.sty, revsymb.sty, 10pt.rtx, aps.rtx, amssymb.sty, amsfonts.sty, 3 eps figures. Phys. Rev. D in press. Email: [email protected] See also http://hs.phys.saga-u.ac.j

Localized U(1) Gauge Fields, Millicharged Particles, and Holography

We consider U(1) gauge fields in a slice of AdS_5 with bulk and boundary mass parameters. The zero mode of a bulk U(1) gauge field can be localized either on the UV or IR brane. This leads to a simple model of millicharged particles in which fermions can have arbitrarily small electric charge. In the electroweak sector we also discuss phenomenological implications of a localized U(1)_Y gauge boson. Using the AdS/CFT correspondence we present the 4D holographic interpretation of the 5D model. In particular the photon is shown to be a composite particle when localized near the IR brane, whereas it is elementary when localized near the UV brane. In the dual interpretation the ``millicharge'' results from an elementary fermion coupling to a composite photon via a vector current with large anomalous dimension.Comment: 26 pages, 1 figur

On phase behavior and dynamical signatures of charged colloidal platelets

We investigate the competition between anisotropic excluded-volume and repulsive electrostatic interactions in suspensions of thin charged colloidal discs, by means of Monte-Carlo simulations and dynamical characterization of the structures found. We show that the original intrinsic anisotropy of the electrostatic potential between charged platelets, obtained within the non-linear Poisson-Boltzmann formalism, not only rationalizes the generic features of the complex phase diagram of charged colloidal platelets such as Gibbsite and Beidellite clays, but also predicts the existence of novel structures. In addition, we find evidences of a strong slowing down of the dynamics upon increasing density.Comment: 6 pages, 6 Figure

Nonlinear Electron Oscillations in a Viscous and Resistive Plasma

New non-linear, spatially periodic, long wavelength electrostatic modes of an electron fluid oscillating against a motionless ion fluid (Langmuir waves) are given, with viscous and resistive effects included. The cold plasma approximation is adopted, which requires the wavelength to be sufficiently large. The pertinent requirement valid for large amplitude waves is determined. The general non-linear solution of the continuity and momentum transfer equations for the electron fluid along with Poisson's equation is obtained in simple parametric form. It is shown that in all typical hydrogen plasmas, the influence of plasma resistivity on the modes in question is negligible. Within the limitations of the solution found, the non-linear time evolution of any (periodic) initial electron number density profile n_e(x, t=0) can be determined (examples). For the modes in question, an idealized model of a strictly cold and collisionless plasma is shown to be applicable to any real plasma, provided that the wavelength lambda >> lambda_{min}(n_0,T_e), where n_0 = const and T_e are the equilibrium values of the electron number density and electron temperature. Within this idealized model, the minimum of the initial electron density n_e(x_{min}, t=0) must be larger than half its equilibrium value, n_0/2. Otherwise, the corresponding maximum n_e(x_{max},t=tau_p/2), obtained after half a period of the plasma oscillation blows up. Relaxation of this restriction on n_e(x, t=0) as one decreases lambda, due to the increase of the electron viscosity effects, is examined in detail. Strong plasma viscosity is shown to change considerably the density profile during the time evolution, e.g., by splitting the largest maximum in two.Comment: 16 one column pages, 11 figures, Abstract and Sec. I, extended, Sec. VIII modified, Phys. Rev. E in pres

Interpretations of the NuTeV sin⁡2θW\sin^2 \theta_W

We summarize theoretical explanations of the three $\sigma$ discrepancy between $\sin^2 \theta_W$ measured by NuTeV and predicted by the Standard Model global fit. Possible new physics explanations ({\it e.g.} an unmized $Z'$) are not compelling. The discrepancy would be reduced by a positive momentum asymmetry $s^-$ in the strange sea; present experimental estimates of $s^-$ are unreliable or incomplete. Upgrading the NuTeV analysis to NLO would alleviate concerns that the discrepancy is a QCD effect.Comment: (proceedings for the NuFact'02 Workshop); reference and footnote added, following the NuTeV proceeding

Damping of bulk excitations over an elongated BEC - the role of radial modes

We report the measurement of Beliaev damping of bulk excitations in cigar shaped Bose Einstein condensates of atomic vapor. By using post selection, excitation line shapes of the total population are compared with those of the undamped excitations. We find that the damping depends on the initial excitation energy of the decaying quasi particle, as well as on the excitation momentum. We model the condensate as an infinite cylinder and calculate the damping rates of the different radial modes. The derived damping rates are in good agreement with the experimentally measured ones. The damping rates strongly depend on the destructive interference between pathways for damping, due to the quantum many-body nature of both excitation and damping products.Comment: 5 pages, 4 figure

Utility of Lymph Node Aspiration in the Diagnosis of Visceral Leishmaniasis in Sudan.

We evaluated lymph node aspiration (LNA) as a simple diagnostic procedure for visceral leishmaniasis (VL). Lymph node aspiration was compared with the direct agglutination test (DAT) using a diagnostic titer > or = 1:6,400 in 7,880 suspected VL patients in eastern Sudan. Compared with DAT, LNA had a sensitivity of 65.1% (95% confidence interval = 63.5-66.6%). Parasite density in LNA correlated strongly with DAT titers (P < 0.0001), and low parasite density accounted for 78.1% of positive LNA results with DAT titers < 1:6,400 (n = 782). Risk factors predictive of a positive LNA result were an age of 1-29 years, male sex, a hemoglobin level < 10.0 g/dL, a DAT titer > or = 1:800, and a location with a higher prevalence of VL. Lymph node and splenic aspirations were similarly accurate as tests of cure after treatment of 50 VL patients in southern Sudan. Pre-treatment LNA results were negative in 20 cases of severe post kala-azar dermal leishmaniasis

Scotland, Catalonia and the “right” to self-determination: a comment suggested by Kathryn Crameri’s “Do Catalans Have the Right to Decide?

No abstract available