15,473 research outputs found

    Data on Apollo 11 and 12 samples. Speculations on petrologic differentiation Final report

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    Petrologic and mineralogic studies of Apollo 11 and 12 lunar rock

    The equation of state of neutron star matter and the symmetry energy

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    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

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    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

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    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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