1,072 research outputs found
Satisfaction with Cognitive Rehabilitation Delivered via the Internet in Persons with Acquired Brain Injury
We examined the level of satisfaction with cognitive rehabilitation delivered via the Internet in persons with moderate to severe acquired brain injury (ABI). Fifteen adults with moderate to severe ABI were randomized to 30 days of Internet-based active treatment (AT) or to a wait list (WL) group, and crossed over to the opposite condition after 30 sessions. Both caregivers and participants were assessed at three time points during the study. This study focused on participant satisfaction with receiving treatment in this manner. Though the results of this study showed no significant treatment effect, the vast majority of participants (>87%) were satisfied with treatment. Treatment satisfaction accounted for 25% of additional variance in predicting lower family ratings of mood difficulties after final assessment (p<.03). Greater satisfaction with treatment was positively correlated with greater employment rate after treatment (r=.63, p=.02), as well as lower family ratings of memory and mood difficulties after final assessment (r=-.59, p=.03; r=-.58, p=.03,). Results suggest that treatment satisfaction in persons with ABI is related to less activity limitations, and maintaining employment after cognitive rehabilitation delivered via the Internet.Â
Patterns of Coastal Land Cover and Estuarine Habitat Quality: Application of Long-term Monitoring Data
2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Regio
Structural materials from recycled high density polyethylene and herbaceous fibers, and method for production
A composite useful for structural components comprised of recycled high density polyethylene and herbaceous fibrous materials and a method to produce composites based on recycled high density polyethylene and chopped herbaceous fibers. An alternative structural composite is disclosed which is comprised of recycled low density polyethylene and chopped herbaceous fibrous material
Quantum state engineering on an optical transition and decoherence in a Paul trap
A single Ca+ ion in a Paul trap has been cooled to the ground state of
vibration with up to 99.9% probability. Starting from this Fock state |n=0> we
have demonstrated coherent quantum state manipulation on an optical transition.
Up to 30 Rabi oscillations within 1.4 ms have been observed. We find a similar
number of Rabi oscillations after preparation of the ion in the |n=1> Fock
state. The coherence of optical state manipulation is only limited by laser and
ambient magnetic field fluctuations. Motional heating has been measured to be
as low as one vibrational quantum in 190 ms.Comment: 4 pages, 5 figure
Speed of ion trap quantum information processors
We investigate theoretically the speed limit of quantum gate operations for
ion trap quantum information processors. The proposed methods use laser pulses
for quantum gates which entangle the electronic and vibrational degrees of
freedom of the trapped ions. Two of these methods are studied in detail and for
both of them the speed is limited by a combination of the recoil frequency of
the relevant electronic transition, and the vibrational frequency in the trap.
We have experimentally studied the gate operations below and above this speed
limit. In the latter case, the fidelity is reduced, in agreement with our
theoretical findings. //
Changes: a) error in equ. 24 and table III repaired b) reference Jonathan et
al, quant-ph/ 0002092, added (proposes fast quantum gates using the AC-Stark
effect)Comment: 10 pages, 4 figure
Absolute Frequency Measurements of the Hg^+ and Ca Optical Clock Transitions with a Femtosecond Laser
The frequency comb created by a femtosecond mode-locked laser and a
microstructured fiber is used to phase coherently measure the frequencies of
both the Hg^+ and Ca optical standards with respect to the SI second as
realized at NIST. We find the transition frequencies to be f_Hg=1 064 721 609
899 143(10) Hz and f_Ca=455 986 240 494 158(26) Hz, respectively. In addition
to the unprecedented precision demonstrated here, this work is the precursor to
all-optical atomic clocks based on the Hg^+ and Ca standards. Furthermore, when
combined with previous measurements, we find no time variations of these atomic
frequencies within the uncertainties of |(df_Ca/dt)/f_Ca| < 8 x 10^{-14}
yr^{-1}, and |(df_Hg/dt)/f_Hg|< 30 x 10^{-14} yr^{-1}.Comment: 6 pages, including 4 figures. RevTex 4. Submitted to Phys. Rev. Let
Using machine learning to enhance prediction of atrial fibrillation recurrence after catheter ablation
Motional sidebands and direct measurement of the cooling rate in the resonance fluorescence of a single trapped ion
Resonance fluorescence of a single trapped ion is spectrally analyzed using a
heterodyne technique. Motional sidebands due to the oscillation of the ion in
the harmonic trap potential are observed in the fluorescence spectrum. From the
width of the sidebands the cooling rate is obtained and found to be in
agreement with the theoretical prediction.Comment: 4 pages, 4 figures. Final version after minor changes, 1 figure
replaced; to be published in PRL, July 10, 200
Trapped ions in the strong excitation regime: ion interferometry and non--classical states
The interaction of a trapped ion with a laser beam in the strong excitation
regime is analyzed. In this regime, a variety of non--classical states of
motion can be prepared either by using laser pulses of well defined area, or by
an adiabatic passage scheme based on the variation of the laser frequency. We
show how these states can be used to investigate fundamental properties of
quantum mechanics. We also study possible applications of this system to build
an ion interferometer.Comment: 9 pages, Revtex format, 5 compressed postscript figure
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