3,644 research outputs found

    Phase Diagram Of The Biham-Middleton-Levine Traffic Model In Three Dimensions

    Get PDF
    We study numerically the behavior of the Biham-Middleton-Levine traffic model in three dimensions. Our extensive numerical simulations show that the phase diagram for this model in three dimensions is markedly different from that in one and two dimensions. In addition to the full speed moving as well as the completely jamming phases, whose respective average asymptotic car speeds equal one and zero, we observe an extensive region of car densities ρ\rho with a low but non-zero average asymptotic car speed. The transition from this extensive low average asymptotic car speed region to the completely jamming region is at least second order. We argue that this low speed region is a result of the formation of a spatially-limited-extended percolating cluster. Thus, this low speed phase is present in n>3n > 3 dimensional Biham-Middleton-Levine model as well.Comment: Minor clarifications, 1 figure adde

    Housing Bubbles: A Tale of Two Cities

    Get PDF
    postprin

    Pd/Cu Site Interchange and Non-Fermi-Liquid Behavior in UCu_4Pd

    Full text link
    X-ray-absorption fine-structure measurements of the local structure in UCu_4Pd are described which indicate a probable lattice-disorder origin for non-Fermi-liquid behavior in this material. Short Pd-Cu distances are observed, consistent with 24 +/- 3% of the Pd atoms occupying nominally Cu sites. A "Kondo disorder" model, based on the effect on the local Kondo temperature T_K of this interchange and some additional bond-length disorder, agrees quantitatively with previous experimental susceptibility data, and therefore also with specific heat and magnetic resonance experiments.Comment: 4 pages, 3 PostScript figures, to be published in PR

    Do prophylactic antipyretics reduce vaccination-associated symptoms in children?

    Get PDF
    Q: Do prophylactic antipyretics reduce vaccination-associated symptoms in children? Yes for acetaminophen, not so much for ibuprofen. Prophylactic acetaminophen reduces the odds of febrile reactions in the first 48 hours after vaccination by 40% to 65% and pain of all grades by 36% to 43%. In contrast, prophylactic ibuprofen reduces pain of all grades by 34% only after primary vaccination and doesn't alter pain after boosters. Nor does it alter early febrile reactions (strength of recommendation [SOR]: B, meta-analysis of randomized clinical trials [RCTs] with moderate-to-high risk of bias). Prophylactic administration of acetaminophen or ibuprofen is associated with a reduction in antibody response to the primary vaccine series and to influenza vaccine, but antibody responses still achieve seroprotective levels (SOR: C, bench research).Hang Chau-Glendinning, DO; Blair Baber, PharmD; Jon O. Neher, MD (Valley Family Medicine Residency, University of Washington at Valley Medical Center, Renton); Sarah Safranek, MLIS (University of Washington Health Sciences Library, Seattle)Includes bibliographical reference

    Opportunities for Nuclear Astrophysics at FRANZ

    Full text link
    The "Frankfurter Neutronenquelle am Stern-Gerlach-Zentrum" (FRANZ), which is currently under development, will be the strongest neutron source in the astrophysically interesting energy region in the world. It will be about three orders of magnitude more intense than the well-established neutron source at the Research Center Karlsruhe (FZK)

    The effects of rhythmic sensory cues on the temporal dynamics of human gait

    Get PDF
    Walking is a complex, rhythmic task performed by the locomotor system. However, natural gait rhythms can be influenced by metronomic auditory stimuli, a phenomenon of particular interest in neurological rehabilitation. In this paper, we examined the effects of aural, visual and tactile rhythmic cues on the temporal dynamics associated with human gait. Data were collected from fifteen healthy adults in two sessions. Each session consisted of five 15-minute trials. In the first trial of each session, participants walked at their preferred walking speed. In subsequent trials, participants were asked to walk to a metronomic beat, provided through visually, aurally, tactile or all three cues (simultaneously and in sync), the pace of which was set to the preferred walking speed of the first trial. Using the collected data, we extracted several parameters including: gait speed, mean stride interval, stride interval variability, scaling exponent and maximum Lyapunov exponent. The extracted parameters showed that rhythmic sensory cues affect the temporal dynamics of human gait. The auditory rhythmic cue had the greatest influence on the gait parameters, while the visual cue had no statistically significant effect on the scaling exponent. These results demonstrate that visual rhythmic cues could be considered as an alternative cueing modality in rehabilitation without concern of adversely altering the statistical persistence of walking. © 2012 Sejdić et al

    Universal Cubic Eigenvalue Repulsion for Random Normal Matrices

    Full text link
    Random matrix models consisting of normal matrices, defined by the sole constraint [N,N]=0[N^{\dag},N]=0, will be explored. It is shown that cubic eigenvalue repulsion in the complex plane is universal with respect to the probability distribution of matrices. The density of eigenvalues, all correlation functions, and level spacing statistics are calculated. Normal matrix models offer more probability distributions amenable to analytical analysis than complex matrix models where only a model wth a Gaussian distribution are solvable. The statistics of numerically generated eigenvalues from gaussian distributed normal matrices are compared to the analytical results obtained and agreement is seen.Comment: 15 pages, 2 eps figures. to appar in Physical Review

    Evidence for a common physical description of non-Fermi-liquid behavior in f-electron systems

    Full text link
    The non-Fermi-liquid (NFL) behavior observed in the low temperature specific heat C(T)C(T) and magnetic susceptibility χ(T)\chi(T) of f-electron systems is analyzed within the context of a recently developed theory based on Griffiths singularities. Measurements of C(T)C(T) and χ(T)\chi(T) in the systems Th1xUxPd2Al3Th_{1-x}U_{x}Pd_{2}Al_{3}, Y1xUxPd3Y_{1-x}U_{x}Pd_3, and UCu5xMxUCu_{5-x}M_{x} (M = Pd, Pt) are found to be consistent with C(T)/Tχ(T)T1+λC(T)/T \propto \chi(T) \propto T^{-1+\lambda} predicted by this model with λ<1\lambda <1 in the NFL regime. These results suggest that the NFL properties observed in a wide variety of f-electron systems can be described within the context of a common physical picture.Comment: 4 pages, 4 figure

    Scaling factors for the in vitro-in vivo extrapolation (IV-IVE) of renal drug and xenobiotic glucuronidation clearance.

    Get PDF
    AIM: To determine the scaling factors required for inclusion of renal drug glucuronidation clearance in the prediction of total clearance via glucuronidation (CLUGT ). METHODS: Microsomal protein per gram of kidney (MPPGK) was determined for human 'mixed' kidney (n = 5) microsomes (MKM). The glucuronidation activities of deferiprone (DEF), propofol (PRO) and zidovudine (AZT) by MKM and paired cortical (KCM) and medullary (KMM) microsomes were measured, along with the UGT 1A6, 1A9 and 2B7 protein contents of each enzyme source. Unbound intrinsic clearances (CLint,u,UGT ) for PRO and morphine (MOR; 3- and 6-) glucuronidation by MKM, human liver microsomes (HLM) and recombinant UGT1A9 and 2B7 were additionally determined. Data were scaled using in vitro-in vivo extrapolation (IV-IVE) approaches to assess the influence of renal CLint,u,UGT on the prediction accuracy of the calculated CLUGT values of PRO and MOR. RESULTS: MPPGK was 9.3 ± 2.0 mg g(-1) (mean ± SD). The respective rates of DEF (UGT1A6), PRO (UGT1A9) and AZT (UGT2B7) glucuronidation by KCM were 1.4-, 5.2- and 10.5-fold higher than those for KMM. UGT 1A6, 1A9 and 2B7 were the only enzymes expressed in kidney. Consistent with the activity data, the abundance of each of these enzymes was greater in KCM than in KMM. The abundance of UGT1A9 in MKM (61.3 pmol mg(-1) ) was 2.7 fold higher than that reported for HLM. CONCLUSIONS: Scaled renal PRO glucuronidation CLint,u,UGT was double that of liver. Renal CLint,u,UGT should be accounted for in the IV-IVE of UGT1A9 and considered for UGT1A6 and 2B7 substrates
    corecore