1,218 research outputs found
Beauty, elegance, grace, and sexiness compared
Beauty is the single most frequently and most broadly used aesthetic virtue term. The present study aimed at providing higher conceptual resolution to the broader notion of beauty by comparing it with three closely related aesthetically evaluative concepts which are likewise lexicalized across many languages: elegance, grace(fulness), and sexiness. We administered a variety of questionnaires that targeted perceptual qualia, cognitive and affective evaluations, as well as specific object properties that are associated with beauty, elegance, grace, and sexiness in personal looks, movements, objects of design, and other domains. This allowed us to reveal distinct and highly nuanced profiles of how a beautiful, elegant, graceful, and sexy appearance is subjectively perceived. As aesthetics is all about nuances, the fine-grained conceptual analysis of the four target concepts of our study provides crucial distinctions for future research
Doppler cooling of calcium ions using a dipole-forbidden transition
Doppler cooling of calcium ions has been experimentally demonstrated using
the S1/2 to D5/2 dipole-forbidden transition. Scattering forces and
fluorescence levels a factor of 5 smaller than for usual Doppler cooling on the
dipole allowed S1/2 to P1/2 transition have been achieved. Since the light
scattered from the ions can be monitored at (violet) wavelengths that are very
different from the excitation wavelengths, single ions can be detected with an
essentially zero background level. This, as well as other features of the
cooling scheme, can be extremely valuable for ion trap based quantum
information processing.Comment: 4 pages, 4 figures, minor changes to commentary and reference
Fast accumulation of ions in a dual trap
Transporting charged particles between different traps has become an
important feature in high-precision spectroscopy experiments of different
types. In many experiments in atomic and molecular physics, the optical probing
of the ions is not carried out at the same location as the creation or state
preparation. In our double linear radio-frequency trap, we have implemented a
fast protocol allowing to shuttle large ion clouds very efficiently between
traps, in times shorter than a millisecond. Moreover, our shuttling protocol is
a one-way process, allowing to add ions to an existing cloud without loss of
the already trapped sample. This feature makes accumulation possible, resulting
in the creation of large ion clouds. Experimental results show, that ion clouds
of large size are reached with laser-cooling, however, the described mechanism
does not rely on any cooling process
Correcting symmetry imperfections in linear multipole traps
Multipole radio-frequency traps are central to collisional experiments in
cryogenic environments. They also offer possibilities to generate new type of
ion crystals topologies and in particular the potential to create infinite
1D/2D structures: ion rings and ion tubes. However, multipole traps have also
been shown to be very sensitive to geometrical misalignment of the trap rods,
leading to additional local trapping minima. The present work proposes a method
to correct non-ideal potentials, by modifying the applied radio-frequency
amplitudes for each trap rod. This approach is discussed for the octupole trap,
leading to the restitution of the ideal Mexican-Hat-like pseudo-potential,
expected in multipole traps. The goodness of the compensation method is
quantified in terms of the choice of the diagnosis area, the residual trapping
potential variations, the required adaptation of the applied radio-frequency
voltage amplitudes, and the impact on the trapped ion structures. Experimental
implementation for macroscopic multipole traps is also discussed, in order to
propose a diagnostic method with respect to the resolution and stability of the
trap drive. Using the proposed compensation technique, we discuss the
feasibility of generating a homogeneous ion ring crystal, which is a measure of
quality for the obtained potential well
Gap in Patient Expectations of Deep Brain Stimulation for the Treatment of Parkinson\u27s Disease
Abstract
Purpose: This project studied a specific group of patients with Parkinson’s disease to: determine if they were asked to verbalize expectations of DBS pre-operatively; determine if patient expectations were met post-operatively; gain information that could aid in improved pre-operative patient education for deep brain stimulation (DBS), address unrealistic expectations before surgery, and meet patient expectations post-operatively.
Methodology: This study was a retrospective, single academic center, two-part design that included a questionnaire and chart review of 29 patients. Those included were patients with Parkinson’s disease who had DBS programming at the academic center, between the years 2007 and 2014.
Results: Discrepancy was observed between expectations discussed, with 71.4% (SEM-8.7%) indicating they had been asked to verbalize expectations pre-operatively, compared to only 48.3% (SEM-9.4) of charts reviewed having documentation of pre-operative patient expectation discussions. One hundred percent of the sample were in at least some agreement that DBS met overall post-operative expectations, but only 46.4% (SEM-9.6%) were in complete agreement.
Conclusions: Overall, DBS patients’ expectations were met to some degree; however, pre-op education should focus on what DBS does and does not improve, patients’ expectations should be verbalized both pre and post-operatively, and documentation of expectations and education should be included in the patient chart
Two-step Doppler cooling of a three-level ladder system with an intermediate metastable level
Doppler laser cooling of a three-level ladder system using two near-resonant
laser fields is analyzed in the case of the intermediate level being metastable
while the upper level is short-lived. Analytical as well as numerical results
for e.g. obtainable scattering rates and achievable temperatures are presented.
When appropriate, comparisons with two-level single photon Doppler laser
cooling is made. These results are relevant to recent experimental Doppler
laser cooling investigations addressing intercombination lines in alkali-earth
metal atoms and quadrupole transitions in alkali-earth metal ions.Comment: accepted by Phys Rev
Parallel ion strings in linear multipole traps
Additional radio-frequency (rf) potentials applied to linear multipole traps
create extra field nodes in the radial plane which allow one to confine single
ions, or strings of ions, in totally rf field-free regions. The number of nodes
depends on the order of the applied multipole potentials and their relative
distance can be easily tuned by the amplitude variation of the applied
voltages. Simulations using molecular dynamics show that strings of ions can be
laser cooled down to the Doppler limit in all directions of space. Once cooled,
organized systems can be moved with very limited heating, even if the cooling
process is turned off
Dark resonances as a probe for the motional state of a single ion
Single, rf-trapped ions find various applications ranging from metrology to
quantum computation. High-resolution interrogation of an extremely weak
transition under best observation conditions requires an ion almost at rest. To
avoid line-broadening effects such as the second order Doppler effect or rf
heating in the absence of laser cooling, excess micromotion has to be
eliminated as far as possible. In this work the motional state of a confined
three-level ion is probed, taking advantage of the high sensitivity of observed
dark resonances to the trapped ion's velocity. Excess micromotion is controlled
by monitoring the dark resonance contrast with varying laser beam geometry. The
influence of different parameters such as the cooling laser intensity has been
investigated experimentally and numerically
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