Dephasing in Disordered Conductors due to Fluctuating Electric Fields

We develop a novel eikonal expansion for the Cooperon to study the effect of space- and time-dependent electric fields on the dephasing rate of disordered conductors. For randomly fluctuating fields with arbitrary covariance we derive a general expression for the dephasing rate which is free of infrared divergencies in reduced dimensions. For time-dependent external fields with finite wavelength and sufficiently small amplitude we show that the dephasing rate is proportional to the square root of the electromagnetic power coupled into the system, in agreement with data by Wang and Lindelof [Phys. Rev. Lett. {\bf{59}}, 1156 (1987)].Comment: 17 Latex-pages, one figure; we now give more technical details and discuss the screening problem more carefully; to appear in Phys. Rev.

Fibrinogen-γ proteolysis and solubility dynamics during apoptotic mouse liver injury: Heparin prevents and treats liver damage

Fas ligand (FasL)-mediated hepatocyte apoptosis occurs in the context of acute liver injury that can be accompanied by intravascular coagulation (IC). We tested the hypothesis that analysis of selected protein fractions from livers undergoing apoptosis will shed light on mechanisms that are involved in liver injury that might be amenable to intervention. Proteomic analysis of the major insoluble liver proteins after FasL exposure for 4-5 hours identified fibrinogen-γ (FIB-γ) dimers and FIB-γ–containing high molecular mass complexes among the major insoluble proteins visible via Coomassie blue staining. Presence of the FIB-γ–containing products was confirmed using FIB-γ–specific antibodies. The FIB-γ–containing products partition selectively and quantitatively into the liver parenchyma after inducing apoptosis. Similar formation of FIB-γ products occurs after acetaminophen administration. The observed intrahepatic IC raised the possibility that heparin therapy may ameliorate FasL-mediated liver injury. Notably, heparin administration in mice 4 hours before or up to 2 hours after FasL injection resulted in a dramatic reduction of liver injury—including liver hemorrhage, serum alanine aminotransferase, caspase activation, and liver apoptosis—compared with heparin-untreated mice. Heparin did not directly interfere with FasL-induced apoptosis in isolated hepatocytes, and heparin-treated mice survived the FasL-induced liver injury longer compared with heparin-untreated animals. There was a sharp, near-simultaneous rise in FasL-induced intrahepatic apoptosis and coagulation, with IC remaining stable while apoptosis continued to increase. Conclusion: Formation of FIB-γ dimers and their high molecular mass products are readily detectable within the liver during mouse apoptotic liver injury. Heparin provides a potential therapeutic modality, because it not only prevents extensive FasL-related liver injury but also limits the extent of injury if given at early stages of injury exposure. (H EPATOLOGY 2011;)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83742/1/24203_ftp.pd

Medical Student and Resident Foley Catheterization training program to decrease Post-Operative Catheter Associated Urinary Tract Infections

Objective: Determine whether a more comprehensive medical student urinary catherer training curriculum can be successful in decreasing post-operative CAUTI rates in general and vascular surgery patient populations. Primary target: Reduce post-operative UTI rates by 0.5% over 6 months Secondary targets: Achieve 100% medical student confidence in Foley catheter placement, understanding indications and contraindications to urinary catheterization. Improve objective performance of urinary catheterization skills as determined by objective clinical skills exam (OSCE) scores.https://jdc.jefferson.edu/patientsafetyposters/1000/thumbnail.jp

Scaling of the conductance distribution near the Anderson transition

The single parameter scaling hypothesis is the foundation of our understanding of the Anderson transition. However, the conductance of a disordered system is a fluctuating quantity which does not obey a one parameter scaling law. It is essential to investigate the scaling of the full conductance distribution to establish the scaling hypothesis. We present a clear cut numerical demonstration that the conductance distribution indeed obeys one parameter scaling near the Anderson transition

Calculation of the average Green's function of electrons in a stochastic medium via higher-dimensional bosonization

The disorder averaged single-particle Green's function of electrons subject to a time-dependent random potential with long-range spatial correlations is calculated by means of bosonization in arbitrary dimensions. For static disorder our method is equivalent with conventional perturbation theory based on the lowest order Born approximation. For dynamic disorder, however, we obtain a new non-perturbative expression for the average Green's function. Bosonization also provides a solid microscopic basis for the description of the quantum dynamics of an interacting many-body system via an effective stochastic model with Gaussian probability distribution.Comment: RevTex, no figure

Quasi-particle behavior of composite fermions in the half-filled Landau level

We calculate the effect of infrared fluctuations of the Chern-Simons gauge field on the single-particle Green's function of composite fermions in the half-filled Landau level via higher-dimensional bosonization on a curved Fermi surface. We find that composite fermions remain well-defined quasi-particles, with an effective mass given by the mean-field value, but with anomalously large damping and a spectral function that contains considerable weight away from the quasi-particle peak.Comment: reference added; accepted for publication in Phys. Rev. Let

Non-Relativistic Fermions Coupled to Transverse Gauge-Fields: The Single-Particle Green's Function in Arbitrary Dimension

We use a bosonization approach to calculate the single-particle Green's function $G ( {\bf{r}} , \tau )$ of non-relativistic fermions coupled to transverse gauge-fields in arbitrary dimension $d$. We find that in $d>3$ transverse gauge-fields do not destroy the Fermi liquid, although for $d < 6$ the quasi-particle damping is anomalously large. For $d \rightarrow 3$ the quasi-particle residue vanishes as $Z \propto \exp [ - \frac{1}{2 \pi ( d-3)} (\frac{ \kappa}{mc } )^2 ]$, where $\kappa$ is the Thomas-Fermi wave-vector, $m$ is the mass of the electrons, and $c$ is the velocity of the gauge-particle. In $d=3$ the system is a Luttinger liquid, with anomalous dimension $\gamma_{\bot} = \frac{1}{6 \pi} ( \frac{ \kappa}{mc} )^2$. For $d < 3$ we find that $G ({\bf{r}} , 0 )$ decays exponentially at large distances.Comment: RevTex, no figures

Correlation functions of higher-dimensional Luttinger liquids

Using higher-dimensional bosonization, we study correlation functions of fermions with singular forward scattering. Following Bares and Wen [Phys. Rev. B 48, 8636 (1993)], we consider density-density interactions in d dimensions that diverge for small momentum transfers as q^{- eta} with eta = 2 (d-1). In this case the single-particle Green's function shows Luttinger liquid behavior. We discuss the momentum distribution and the density of states and show that, in contrast to d=1, in higher dimensions the scaling behavior cannot be characterized by a single anomalous exponent. We also calculate the irreducible polarization for q close to 2 k_F and show that the leading singularities cancel. We discuss consequences for the effect of disorder on higher-dimensional Luttinger liquids.Comment: 7 RevTex pages, 2 figures, minor modifications, to appear in Phys. Rev. B (Feb. 1999

The Metabochip, a Custom Genotyping Array for Genetic Studies of Metabolic, Cardiovascular, and Anthropometric Traits

PMCID: PMC3410907This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Evaluation Research and Institutional Pressures: Challenges in Public-Nonprofit Contracting

This article examines the connection between program evaluation research and decision-making by public managers. Drawing on neo-institutional theory, a framework is presented for diagnosing the pressures and conditions that lead alternatively toward or away the rational use of evaluation research. Three cases of public-nonprofit contracting for the delivery of major programs are presented to clarify the way coercive, mimetic, and normative pressures interfere with a sound connection being made between research and implementation. The article concludes by considering how public managers can respond to the isomorphic pressures in their environment that make it hard to act on data relating to program performance.This publication is Hauser Center Working Paper No. 23. The Hauser Center Working Paper Series was launched during the summer of 2000. The Series enables the Hauser Center to share with a broad audience important works-in-progress written by Hauser Center scholars and researchers