Ferrohydrodynamics: testing a new magnetization equation

A new magnetization equation recently derived from irreversible thermodynamics is employed to the calculation of an increase of ferrofluid viscosity in a magnetic field. Results of the calculations are compared with those obtained on the basis of two well-known magnetization equations. One of the two was obtained phenomenologically, another one was derived microscopically from the Fokker-Planck equation. It is shown that the new magnetization equation yields a quite satisfactory description of magnetiviscosity in the entire region of magnetic field strength and the flow vorticity. This equation turns out to be valid -- like the microscopically derived equation but unlike the former phenomenological equation -- even far from equilibrium, and so it should be recommended for further applications.Comment: 4 pages, 3 figures, Submitted to Phys. Rev.

Comment on "Magnetoviscosity and relaxation in ferrofluids"

It is shown and discussed how the conventional system of hydrodynamic equations for ferrofluids was derived. The set consists of the equation of fluid motion, the Maxwell equations, and the magnetization equation. The latter was recently revised by Felderhof [Phys. Rev. E, v.62, p.3848 (2000)]. His phenomenological magnetization equation looks rather like corresponding Shliomis' equation, but leads to wrong consequences for the dependence of ferrofluid viscosity and magnetization relaxation time on magnetic field.Comment: 6 pages, 1 figure, Submitted to Phys. Rev.

Variational Monte Carlo study of the ground state properties and vacancy formation energy of solid para-H2 using a shadow wave function

A Shadow Wave Function (SWF) is employed along with Variational Monte Carlo techniques to describe the ground state properties of solid molecular para-hydrogen. The study has been extended to densities below the equilibrium value, to obtain a parameterization of the SWF useful for the description of inhomogeneous phases. We also present an estimate of the vacancy formation energy as a function of the density, and discuss the importance of relaxation effects near the vacant site

Universality of Sypersymmetric Attractors

The macroscopic entropy-area formula for supersymmetric black holes in N=2,4,8 theories is found to be universal: in d=4 it is always given by the square of the largest of the central charges extremized in the moduli space. The proof of universality is based on the fact that the doubling of unbroken supersymmetry near the black hole horizon requires that all central charges other than Z=M vanish at the attractor point for N=4,8. The ADM mass at the extremum can be computed in terms of duality symmetric quartic invariants which are moduli independent. The extension of these results for d=5, N=1,2,4 is also reported. A duality symmetric expression for the energy of the ground state with spontaneous breaking of supersymmetry is provided by the power 1/2 (2/3) of the black hole area of the horizon in d=4 (d=5). It is suggested that the universal duality symmetric formula for the energy of the ground state in supersymmetric gravity is given by the modulus of the maximal central charge at the attractor point in any supersymmetric theory in any dimension.Comment: few misprints removed, version to appear in Phys. Rev. 20 pages, 1 figur

Insulin-Like Growth Factor-1 but Not Insulin Predicts Cognitive Decline in Huntington's Disease

BACKGROUND: Huntington\u27s disease (HD) is one of several neurodegenerative disorders that have been associated with metabolic alterations. Changes in Insulin Growth Factor 1 (IGF-1) and/or insulin input to the brain may underlie or contribute to the progress of neurodegenerative processes. Here, we investigated the association over time between changes in plasma levels of IGF-1 and insulin and the cognitive decline in HD patients. METHODS: We conducted a multicentric cohort study in 156 patients with genetically documented HD aged from 22 to 80 years. Among them, 146 patients were assessed at least twice with a follow-up of 3.5 ± 1.8 years. We assessed their cognitive decline using the Unified Huntington\u27s Disease Rating Scale, and their IGF-1 and insulin plasmatic levels, at baseline and once a year during the follow-up. Associations were evaluated using a mixed-effect linear model. RESULTS: In the cross-sectional analysis at baseline, higher levels of IGF-1 and insulin were associated with lower cognitive scores and thus with a higher degree of cognitive impairment. In the longitudinal analysis, the decrease of all cognitive scores, except the Stroop interference, was associated with the IGF-1 level over time but not of insulin. CONCLUSIONS: IGF-1 levels, unlike insulin, predict the decline of cognitive function in HD

Unconventional MBE Strategies from Computer Simulations for Optimized Growth Conditions

We investigate the influence of step edge diffusion (SED) and desorption on Molecular Beam Epitaxy (MBE) using kinetic Monte-Carlo simulations of the solid-on-solid (SOS) model. Based on these investigations we propose two strategies to optimize MBE growth. The strategies are applicable in different growth regimes: During layer-by-layer growth one can exploit the presence of desorption in order to achieve smooth surfaces. By additional short high flux pulses of particles one can increase the growth rate and assist layer-by-layer growth. If, however, mounds are formed (non-layer-by-layer growth) the SED can be used to control size and shape of the three-dimensional structures. By controlled reduction of the flux with time we achieve a fast coarsening together with smooth step edges.Comment: 19 pages, 7 figures, submitted to Phys. Rev.

Microbial Translocation Is Associated with Extensive Immune Activation in Dengue Virus Infected Patients with Severe Disease

Background:Severe dengue virus (DENV) disease is associated with extensive immune activation, characterized by a cytokine storm. Previously, elevated lipopolysaccharide (LPS) levels in dengue were found to correlate with clinical disease severity. In the present cross-sectional study we identified markers of microbial translocation and immune activation, which are associated with severe manifestations of DENV infection.Methods:Serum samples from DENV-infected patients were collected during the outbreak in 2010 in the State of São Paulo, Brazil. Levels of LPS, lipopolysaccharide binding protein (LBP), soluble CD14 (sCD14) and IgM and IgG endotoxin core antibodies were determined by ELISA. Thirty cytokines were quantified using a multiplex luminex system. Patients were classified according to the 2009 WHO classification and the occurrence of plasma leakage/shock and hemorrhage. Moreover, a (non-supervised) cluster analysis based on the expression of the quantified cytokines was applied to identify groups of patients with similar cytokine profiles. Markers of microbial translocation were linked to groups with similar clinical disease severity and clusters with similar cytokine profiles.Results:Cluster analysis indicated that LPS levels were significantly increased in patients with a profound pro-inflammatory cytokine profile. LBP and sCD14 showed significantly increased levels in patients with severe disease in the clinical classification and in patients with severe inflammation in the cluster analysis. With both the clinical classification and the cluster analysis, levels of IL-6, IL-8, sIL-2R, MCP-1, RANTES, HGF, G-CSF and EGF were associated with severe disease.Conclusions:The present study provides evidence that both microbial translocation and extensive immune activation occur during severe DENV infection and may play an important role in the pathogenesis

Guidelines for clinical pharmacological practices in Huntington's disease

OBJECTIVE: Evidence-based medicine is a difficult goal to achieve in rare diseases where randomized controlled trials are lacking. This report provides guidelines that capitalize on both the literature and expertise of the French National Huntington Disease Reference Centre to optimalize pharmacological therapeutic interventions for Huntington\u27s disease (HD). MATERIAL AND METHODS: HD experts conducted a systematic analysis of the literature from 1965 to 2013, using a scoring procedure established by the French National Authority for Health. These experts offered their views when evidence was missing to set up provisional guidelines for care in HD. These guidelines were then scored and amended through two subsequent online questionnaires (using SurveyMonkey scoring), and one face-to-face meeting with an external multidisciplinary working group as a step towards validation. RESULTS: Except for the beneficial effects of tetrabenazine in chorea, none of the published recommendations were grounded on established scientific evidence. Second-generation antipsychotics are nevertheless the first choice for patients with psychiatric manifestations (low level of evidence). All other guidelines are based on low-level evidence and little professional agreement. CONCLUSION: Patients\u27 care has greatly improved over the last few years despite the lack of high-level evidence standards. Guidelines are based on the expertise of trained specialists from the French National Plan for Rare Diseases. This strategy should now be extended internationally to promote future studies and to harmonize worldwide care of HD

Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events

The $B^0$-$\bar B^0$ oscillation frequency has been measured with a sample of 23 million \B\bar B pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives $\Delta m_d = 0.493 \pm 0.012{(stat)}\pm 0.009{(syst)}$ ps$^{-1}$.Comment: 7 pages, 1 figure, submitted to Physical Review Letter