15,686 research outputs found
Data on Apollo 11 and 12 samples. Speculations on petrologic differentiation Final report
Petrologic and mineralogic studies of Apollo 11 and 12 lunar rock
The equation of state of neutron star matter and the symmetry energy
We present an overview of microscopical calculations of the Equation of State
(EOS) of neutron matter performed using Quantum Monte Carlo techniques. We
focus to the role of the model of the three-neutron force in the high-density
part of the EOS up to a few times the saturation density. We also discuss the
interplay between the symmetry energy and the neutron star mass-radius
relation.
The combination of theoretical models of the EOS with recent neutron stars
observations permits us to constrain the value of the symmetry energy and its
slope. We show that astrophysical observations are starting to provide
important insights into the properties of neutron star matter.Comment: 7 pages, 3 figure, talk given at the 11th International Conference on
Nucleus-Nucleus Collisions (NN2012), San Antonio, Texas, USA, May 27-June 1,
2012. To appear in the NN2012 Proceedings in Journal of Physics: Conference
Series (JPCS
Hearing loss and auditory processing ability in people with aphasia
BACKGROUND: Hearing loss can add to the linguistic deficits present in aphasia to make
comprehension of speech difficult. Although some studies document a relatively high
prevalence of hearing loss in adults with aphasia, many people with aphasia do not have
their hearing tested. Self-reported disability measures offer a possible alternative to pure-
tone audiometry when this service is not readily available.
AIMS: This study aims to investigate the prevalence of hearing loss in a group of people
with aphasia and to determine the usefulness of self-reported measures to screen for
hearing impairment.
METHODS AND PROCEDURES: Hearing ability was measured using pure-tone audiometry and
five measures of auditory processing, which looked at speech perception in quiet and
noise, for 21 individuals with aphasia recruited from a community clinic and 21 age-
matched individuals without aphasia. The Speech, Spatial and Qualities of Hearing
Scale (SSQ) and a brief questionnaire exploring whether they had experienced hearing
difficulties were used to measure self-perception of hearing acuity. Differences in scores
between the groups were analysed. Correlations and regressions were used to establish
the relationship between self-perception of hearing and measures of hearing ability.
OUTCOMES AND RESULTS: Despite minimal impairment and a non-significant difference
between performance on pure-tone audiometry for participants with and without apha-
sia, participants with aphasia performed significantly worse on measures of speech
perception in noise than participants without aphasia. They also had a significantly
greater degree of perceived hearing disability. Although SSQ scores were correlated with
some behavioural measures for the participants with aphasia, the SSQ only predicted the
hearing status and speech in noise performance of control participants.
CONCLUSIONS: The results suggest that the prevalence of hearing loss for people with
aphasia (at least for this group) is no greater than the general population. However,
they are significantly more affected in their recognition of speech in noise and experience
greater disability in listening situations than people without aphasia. The latter problems were not predicted by pure-tone audiograms or sound-in-noise performance. The brief
questionnaire was not effective in identifying hearing impairment, indicating the need for
a regular hearing screen to ensure provision of the most effective rehabilitation. Ideally,
the screen should include disability and behavioural measures, as our results suggest they
cannot replace each other. These findings should assist clinicians in setting realistic goals
and delivering interventions in the most effective way for people with aphasia
Spectral Engineering with Coupled Microcavities: Active Control of Resonant Mode-Splitting
Optical mode-splitting is an efficient tool to shape and fine-tune the
spectral response of resonant nanophotonic devices. The active control of
mode-splitting, however, is either small or accompanied by undesired resonance
shifts, often much larger than the resonance-splitting. We report a control
mechanism that enables reconfigurable and widely tunable mode-splitting while
efficiently mitigating undesired resonance shifts. This is achieved by actively
controlling the excitation of counter-traveling modes in coupled resonators.
The transition from a large splitting (80 GHz) to a single-notch resonance is
demonstrated using low power microheaters (35 mW). We show that the spurious
resonance-shift in our device is only limited by thermal crosstalk and
resonance-shift-free splitting control may be achieved.Comment: 4 pages, 3 figure
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