6,178 research outputs found
Quantum critical fluctuations in disordered d-wave superconductors
Quasiparticles in the cuprates appear to be subject to anomalously strong
inelastic damping mechanisms. To explain the phenomenon, Sachdev and
collaborators recently proposed to couple the system to a critically
fluctuating order parameter mode of either id_{xy}- or is-symmetry. Motivated
by the observation that the energies relevant for the dynamics of this mode are
comparable to the scattering rate induced by even moderate impurity
concentrations, we here generalize the approach to the presence of static
disorder. In the id-case, we find that the coupling to disorder renders the
order parameter dynamics diffusive but otherwise leaves much of the
phenomenology observed in the clean case intact. In contrast, the interplay of
impurity scattering and order parameter fluctuations of is-symmetry entails the
formation of a secondary superconductor transition, with a critical temperature
exponentially sensitive to the disorder concentration.Comment: 4 pages, 2 figures include
Higher Order and boundary Scaling Fields in the Abelian Sandpile Model
The Abelian Sandpile Model (ASM) is a paradigm of self-organized criticality
(SOC) which is related to conformal field theory. The conformal fields
corresponding to some height clusters have been suggested before. Here we
derive the first corrections to such fields, in a field theoretical approach,
when the lattice parameter is non-vanishing and consider them in the presence
of a boundary.Comment: 7 pages, no figure
A selected history of expectation bias in physics
The beliefs of physicists can bias their results towards their expectations
in a number of ways. We survey a variety of historical cases of expectation
bias in observations, experiments, and calculations.Comment: 6 pages, 2 figure
Vacancy diffusion in the triangular lattice dimer model
We study vacancy diffusion on the classical triangular lattice dimer model,
sub ject to the kinetic constraint that dimers can only translate, but not
rotate. A single vacancy, i.e. a monomer, in an otherwise fully packed lattice,
is always localized in a tree-like structure. The distribution of tree sizes is
asymptotically exponential and has an average of 8.16 \pm 0.01 sites. A
connected pair of monomers has a finite probability of being delocalized. When
delocalized, the diffusion of monomers is anomalous:Comment: 15 pages, 27 eps figures. submitted to Physical Review
Measurements and predictions of turbulence generation in homogeneous particle-laden flows
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77111/1/AIAA-2000-182-949.pd
Influence of Exposure to Benzo[a]pyrene on Mice Testicular Germ Cells during Spermatogenesis
The objective of this study was to assess the toxicological effect of exposure to benzo(a)pyrene, B[a]P, on germ cells during spermatogenesis. Mice were exposed to B[a]P at 1, 10, 50, and 100 mg/kg/day for 30 days via oral ingestion. Germ cells, including spermatogonia, spermatocytes, pachytene spermatocytes, and round spermatids, were recovered from testes of mice exposed to B[a]P, while mature spermatozoa were isolated from vas deferens. Reproductive organs were collected and weighed. Apoptotic response of germ cells and mature spermatozoa were qualified using the terminal deoxynucleotidyl transferase mediated deoxy-UTP nick end labeling (TUNEL) assay. B[a]P exposure a
PROMOTION OF REPLICATION IN LYMPHOID CELLS BY SPECIFIC THIOLS AND DISULFIDES IN VITRO : EFFECTS ON MOUSE LYMPHOMA CELLS IN COMPARISON WITH SPLENIC LYMPHOCYTES
Numerous lines of mouse lymphoid tumors (13 of 22 tested) showed, with increased sensitivity, a property of normal mouse splenic lymphocytes, the potential for growth promotion in vitro by specific thiols added to standard culture media. For lymphoma L1210 (V), structure activity relationships were examined; 9 of 30 thiols promoted growth; the most active was α-thioglycerol, effective at 0.2 ”M. Thiols became oxidized under conditions of tissue culture and had half-lives of less than 8 h. Disulfides of active thiols promoted growth of lymphoma cells. The mitogenic response of splenic lymphocytes to lectins was increased by thiols-disulfides which promoted the growth of lymphoma cells, but the response varied with the mitogen preparation used and under some conditions thiols-disulfides were inhibitory
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