2,605 research outputs found
\u3cem\u3eUnited States v. The William\u3c/em\u3e and The Phenomena of Jury Nullification in Early 19th Century America
In September 1808, Judge John Davis upheld the constitutionality of the Embargo Act of 1807 under the Constitution’s Article I, Section 8, Clause 3 Interstate Commerce power. Judge Davis’s original opinion curiously lacks any reference to Marbury v. Madison. Judge Davis defends judicial review and rejects the notion of jury nullification. While Judge Davis upheld the embargo’s constitutionality, a subsequent jury trial on the facts resulted in the return of The William to its rightful owners. This case reflects the attempts by early American judges to carve out the power of judicial review and maintain the appearance of an impartial judiciary
An investigation into the feasibility of myoglobin-based single-electron transistors
Myoglobin single-electron transistors were investigated using nanometer- gap
platinum electrodes fabricated by electromigration at cryogenic temperatures.
Apomyoglobin (myoglobin without heme group) was used as a reference. The
results suggest single electron transport is mediated by resonant tunneling
with the electronic and vibrational levels of the heme group in a single
protein. They also represent a proof-of-principle that proteins with redox
centers across nanometer-gap electrodes can be utilized to fabricate
single-electron transistors. The protein orientation and conformation may
significantly affect the conductance of these devices. Future improvements in
device reproducibility and yield will require control of these factors
Ferrimagnetism of dilute Ising antiferromagnets
It is shown that nearest-neighbor antiferromagnetic interactions of identical
Ising spins on imbalanced bipartite lattice and imbalanced bipartite
hierarchical fractal result in ferrimagnetic order instead of antiferromagnetic
one. On some crystal lattices dilute Ising antiferromagnets may also become
ferrimagnets due to the imbalanced nature of the magnetic percolation cluster
when it coexists with the percolation cluster of vacancies. As evidenced by the
existing experiments on , such ferrimagnetism is inherent
property of bcc lattice so thermodynamics of these compounds at low can be
similar to that of antiferromagnet on imbalanced hierarchical fractal.Comment: 6 pages, 4 figure
Nonlocal mixing of supercurrents in Josephson ballistic point contact
We study coherent current states in the mesoscopic superconducting weak link
simultaneously subjected to the order parameter phase difference on the contact
and to the tangential to the junction interface superfluid velocity in the
banks. The Josephson current-phase relation controlled by the external
transport current is obtained. At phase difference close to pi the nonlocal
nature of the Josephson phase-dependent current results in the appearance of
two vortexlike states in the vicinity of the contact.Comment: 4 pages, 6 figures; to be published in Phys. Rev. B; e-mail:
[email protected]
The Symmetries of Nature
The study of the symmetries of nature has fascinated scientists for eons. The application of the formal mathematical description of
symmetries during the last century has produced many breakthroughs in
our understanding of the substructure of matter. In this talk, a number
of these advances are discussed, and the important role that George
Sudarshan played in their development is emphasize
Extraction of the Spin Glass Correlation Length
The peak of the spin glass relaxation rate, S(t)=d{-M_{TRM}(t,t_w)}/H/{d ln
t}, is directly related to the typical value of the free energy barrier which
can be explored over experimental time scales. A change in magnetic field H
generates an energy E_z={N_s}{X_fc}{H^2} by which the barrier heights are
reduced, where X_{fc} is the field cooled susceptibility per spin, and N_s is
the number of correlated spins. The shift of the peak of S(t) gives E_z,
generating the correlation length, Ksi(t,T), for Cu:Mn 6at.% and
CdCr_{1.7}In_{0.3}S_4. Fits to power law dynamics, Ksi(t,T)\propto
{t}^{\alpha(T)} and activated dynamics Ksi(t,T) \propto {ln t}^{1/psi} compare
well with simulation fits, but possess too small a prefactor for activated
dynamics.Comment: 4 pages, 4 figures. Department of Physics, University of California,
Riverside, California, and Service de Physique de l'Etat Condense, CEA
Saclay, Gif sur Yvette, France. To appear in Phys. Rev. Lett. January 4, 199
Ordering in a spin glass under applied magnetic field
Torque, torque relaxation, and magnetization measurements on a AuFe spin
glass sample are reported. The experiments carried out up to 7 T show a
transverse irreversibility line in the (H,T) plane up to high applied fields,
and a distinct strong longitudinal irreversibility line at lower fields. The
data demonstrate for that this type of sample, a Heisenberg spin glass with
moderately strong anisotropy, the spin glass ordered state survives under high
applied fields in contrast to predictions of certain "droplet" type scaling
models. The overall phase diagram closely ressembles those of mean field or
chiral models, which both have replica symmetry breaking transitions.Comment: 4 pages, 3 figures, accepted for PR
HIV infection is associated with elevated biomarkers of immune activation in Ugandan adults with pneumonia.
IntroductionPneumonia is an important cause of morbidity and mortality in persons living with human immunodeficiency virus (HIV) infection. How immune activation differs among HIV-infected and HIV-uninfected adults with pneumonia is unknown.MethodsThe Inflammation, Aging, Microbes, and Obstructive Lung Disease (I AM OLD) Cohort is a prospective cohort of adults with pneumonia in Uganda. In this cross-sectional analysis, plasma was collected at pneumonia presentation to measure the following 12 biomarkers: interleukin 6 (IL-6), soluble tumor necrosis factor receptors 1 and 2 (sTNFR-1 and sTNFR-2), high sensitivity C-reactive protein (hsCRP), fibrinogen, D-dimer, soluble CD27 (sCD27), interferon gamma-inducible protein 10 (IP-10), soluble CD14 (sCD14), soluble CD163 (sCD163), hyaluronan, and intestinal fatty acid binding protein. We asked whether biomarker levels differed between HIV-infected and HIV-uninfected participants, and whether higher levels of these biomarkers were associated with mortality.ResultsOne hundred seventy-three participants were enrolled. Fifty-three percent were HIV-infected. Eight plasma biomarkers-sTNFR-1, sTNFR-2, hsCRP, D-dimer, sCD27, IP-10, sCD14, and hyaluronan-were higher among participants with HIV infection, after adjustment for pneumonia severity. Higher levels of 8 biomarkers-IL-6, sTNFR-1, sTNFR-2, hsCRP, IP-10, sCD14, sCD163, and hyaluronan-were associated with increased 2-month mortality.ConclusionsAs in other clinical contexts, HIV infection is associated with a greater degree of immune activation among Ugandan adults with pneumonia. Some of these are also associated with short-term mortality. Further study is needed to explore whether these biomarkers might predict poor long-term outcomes-such as the development of obstructive lung disease-in patients with HIV who have recovered from pneumonia
Effect of point-contact transparency on coherent mixing of Josephson and transport supercurrents
The influence of electron reflection on dc Josephson effect in a ballistic
point contact with transport current in the banks is considered theoretically.
The effect of finite transparency on the vortex-like currents near the contact
and at the phase difference which has been predicted recently
\cite{KOSh}, is investigated. We show that at low temperatures even a small
reflection on the contact destroys the mentioned vortex-like current states,
which can be restored by increasing of the temperature.Comment: 6 pages, 8 Figures, Latex Fil
Tunneling Via Individual Electronic States in Ferromagnetic Nanoparticles
We measure electron tunneling via discrete energy levels in ferromagnetic
cobalt particles less than 4 nm in diameter, using non-magnetic electrodes. Due
to magnetic anisotropy, the energy of each tunneling resonance shifts as an
applied magnetic field rotates the particle's magnetic moment. We see both
spin-increasing and decreasing tunneling transitions, but we do not observe the
spin degeneracy at small magnetic fields seen previously in non-magnetic
materials. The tunneling spectrum is denser than predicted for independent
electrons, possibly due to spin-wave excitations.Comment: 4 pages, 4 figures. Improved by comments from referees, to appear in
Phys. Rev. Let
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