1,433 research outputs found
Structural and Functional Myocardial Adaptations to Task-Specific Epidural Stimulation in Chronic Spinal Cord Injury.
Cardiovascular disease is a leading cause of mortality, and this is especially true in individuals with spinal cord injury. Decreased systemic blood pressure leads to cardiac deconditioning, thought to be related to the increased cardiovascular morbidity and mortality in this population. This study investigates effects of myocardial loading from epidural stimulation in a group of individuals with spinal cord injury to understand how changes in preload and afterload could lead to beneficial myocardial remodeling. The study conducted echocardiograms to describe the myocardial changes after training with two different types of epidural stimulation intervention: one designed to facilitate movement (Voluntary) and one targeted to maintain systolic blood pressure within a target range of 110-120 mmHg (Cardiovascular). The study showed significant increases in SBP (31±4mmHg) and DBP (17±3mmHg) values with the use of Cardiovascular stimulation compared with Voluntary stimulation. Changes in blood pressure did not, however, lead to significant changes in cardiac structure or function outcomes
How do you know if you ran through a wall?
Stable topological defects of light (pseudo)scalar fields can contribute to
the Universe's dark energy and dark matter. Currently the combination of
gravitational and cosmological constraints provides the best limits on such a
possibility. We take an example of domain walls generated by an axion-like
field with a coupling to the spins of standard-model particles, and show that
if the galactic environment contains a network of such walls, terrestrial
experiments aimed at detection of wall-crossing events are realistic. In
particular, a geographically separated but time-synchronized network of
sensitive atomic magnetometers can detect a wall crossing and probe a range of
model parameters currently unconstrained by astrophysical observations and
gravitational experiments.Comment: 5 pages, 2 figure; to appear in the PR
Gyroscopes based on nitrogen-vacancy centers in diamond
We propose solid-state gyroscopes based on ensembles of negatively charged
nitrogen-vacancy () centers in diamond. In one scheme, rotation of
the nitrogen-vacancy symmetry axis will induce Berry phase shifts in the electronic ground-state coherences proportional to the solid angle
subtended by the symmetry axis. We estimate sensitivity in the range of
in a 1 sensor volume using
a simple Ramsey sequence. Incorporating dynamical decoupling to suppress
dipolar relaxation may yield sensitivity at the level of . With a modified Ramsey scheme, Berry phase shifts in the
hyperfine sublevels would be employed. The projected sensitivity
is in the range of , however the smaller
gyromagnetic ratio reduces sensitivity to magnetic-field noise by several
orders of magnitude. Reaching would represent
an order of magnitude improvement over other compact, solid-state gyroscope
technologies.Comment: 3 figures, 5 page
Wheat and Tares: Responding to Vande Kemp and other Revisionists
In her reaction, Hendrika Vande Kemp ( 1987) joins other critics of psychology in arguing for a new psychology. The authors believe, however, that psychology developed as a science because it was productive and that more subjective methods will gain respectability only through similar productivity. In her critique, Vande Kemp creates a circular argument by suggesting that the authors\u27 position Jacks a proper historicaVphilosophical perspective, and she underestimates the sophistication of those with whom she disagrees. Finally, the authors disagree that there is no point in arguing with the most conservative anti-psychologists, since they may be having a disproportionate influence on public perceptions of psychology
Creating an External Funding Strategy: How to Thrive
Seeking external funding for Extension programs is an important investment in our future. Integral assets to Extension agents as they seek external funding are: understanding the relevance of their programming to the community, ensuring their reliability to conduct successful programming, and having the ability to communicate impact to stakeholders. An external funding strategy allows agents to speak their needs in the language of funders. Through this article, agents can examine strategic questions and logical reasoning and the theory behind them to refine an external funding proposal plan. The packaging checklist will ensure that each proposal is compiled for success
Cancellation of nonlinear Zeeman shifts with light shifts
Nonlinear Zeeman (NLZ) shifts arising from magnetic-field mixing of the two
hyperfine ground-states in alkali atoms lead to splitting of magnetic-resonance
lines. This is a major source of sensitivity degradation and the so-called
"heading errors" of alkali-vapor atomic magnetometers operating in the
geophysical field range (B approx. 0.2-0.7 G). Here, it is shown theoretically
and experimentally that NLZ shifts can be effectively canceled by light shifts
caused by a laser field of appropriate intensity, polarization and frequency, a
technique that can be readily applied in practical situations.Comment: 5 pages, 5 figures, to be published in PR
Temperature dependence of the nitrogen-vacancy magnetic resonance in diamond
The temperature dependence of the magnetic resonance spectra of
nitrogen-vacancy (NV-) ensembles in the range of 280-330 K was studied. Four
samples prepared under different conditions were studied with NV-
concentrations ranging from 10 ppb to 15 ppm. For all of these samples, the
axial zero-field splitting (ZFS) parameter, D, was found to vary significantly
with temperature, T, as dD/dT = -74.2(7) kHz/K. The transverse ZFS parameter,
E, was non-zero (between 4 and 11 MHz) in all samples, and exhibited a
temperature dependence of dE/(EdT) = -1.4(3) x 10^(-4) K^(-1). The results
might be accounted for by considering local thermal expansion. The observation
of the temperature dependence of the ZFS parameters presents a significant
challenge for room-temperature diamond magnetometers and may ultimately limit
their bandwidth and sensitivity.Comment: 5 pages, 2 figures, 1 tabl
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