Ultrafast dynamics of neutral superexcited Oxygen: A direct measurement of the competition between autoionization and predissociation

Using ultrafast extreme ultraviolet pulses, we performed a direct measurement of the relaxation dynamics of neutral superexcited states corresponding to the nl\sigma_g(c^4\Sigma_u^-) Rydberg series of O_2. An XUV attosecond pulse train was used to create a temporally localized Rydberg wavepacket and the ensuing electronic and nuclear dynamics were probed using a time-delayed femtosecond near-infrared pulse. We investigated the competing predissociation and autoionization mechanisms for superexcited molecules and found that autoionization is dominant for the low n Rydberg states. We measured an autoionization lifetime of 92+/-6 fs and 180+/-10 fs for (5s,4d)\sigma_g and (6s,5d)\sigma_g Rydberg state groups respectively. We determine that the disputed neutral dissociation lifetime for the \nu=0 vibrational level of the Rydberg series is 1100+/-100fs.Comment: 5 pages, 4 figure

Letter of the guest editors of the special issue on “Music as a multimodal experience”.

This editorial introduces a collection of papers brought together under the heading of “Music as a Multimodal Experience.” This issue aims to bring to the foreground recent developments in our understanding of music as a multimodal experience

Teaching young musicians expressive performance: an experimental study

Twenty-nine pupils (aged 8–15) took part in an improvisation test and an experimental vs. control group teaching session. The aim of the improvisation test was to explore whether participants had knowledge about the use of expressive cues to convey basic emotions in improvisations. Assessments of the improvisations by four adjudicators indicated that most pupils in this sample could convey happiness, sadness and anger effectively in improvisations, providing a useful starting point for expressive music performance, which was examined in the experimental study. The experimental study investigated whether discussion of musical character is effective for improving pupils’ expressiveness, by comparing outcomes with a control teaching session that focused on accuracy and technical fluency. Participants’ performances of a ‘happy’ and ‘sad’ musical excerpt pre- and post-teaching were assessed by four adjudicators. Results indicated that the experimental teaching had been significantly more effective for improving expressiveness in the ‘sad’ extract than control teaching

Representation of Pitch in Horizontal Space and Its Dependence on Musical and Instrumental Experience

Representation of pitch in horizontal space and its relationship to musical and instrumental experience was examined in three behavioral experiments. Each experiment investigated the influence of a task-irrelevant dimension (pitch or location) on the perception of a task-relevant dimension (location or pitch, respectively). Sine tones with nine different pitches were presented from nine locations, and participants estimated the pitch or location of the stimuli. Experiment 1 showed an influence of the (task irrelevant) pitch of presented stimuli on the perceived location of the stimuli in musically experienced participants only. This influence increased with the degree of musical training of participants. No influence was found of presented location on the perception of pitch. Experiments 2 and 3 investigated the influence of instrumental expertise comparing the responses of a group of flutists with a group of pianists. An interaction with instrumental expertise was found only in Experiment 3, where participants played shortly on their respective instruments before doing the perceptual judgments. The experiments indicate that musical training in general influence the pitch-location association, and pianistic experience in particular

On the fluidity of consonance and dissonance: The influence of musical context

The consonance/dissonance (C/D) level of a triadic chord is not a fixed or absolute value. Rather, it is fluid, since C/D depends both on a chord’s sonic characteristics and on the musical context in which it appears. To test the fluidity of C/D—the extent to which C/D perception is dependent on musical context—4 types of chords (major, minor, augmented, and diminished triads) were presented in isolation (“without musical context”) and as part of a short cadence (IV-V-I, “with musical context”). The C/D level of each chord was judged, as was the overall C/D and pleasantness/unpleasantness (P/U) level of the cadences. When isolated, major triads were considered most consonant, followed by minor and diminished triads, while augmented triads were judged most dissonant. In the context of a musical cadence, this rank order remained the same. However, evaluations of the dissonance of augmented and diminished chords varied depending on each chord’s functional position within the cadence. For instance, diminished triads were relatively consonant when on the subdominant, while augmented triads were relatively dissonant when on the tonic. These findings lend support to the hypotheses that: (a) the degree to which the harmonic function of a chord is familiar, and (b) the degree to which a chord’s stability (and hence also the listener’s expectation) is violated contribute to the perception of C/D

Conceptions about teaching and learning of expressivity in music among Higher Education teachers and students

This work aimed to analyse factors related to conceptions and beliefs about expressivity in music among students and teachers. A questionnaire with 11 Likert-type items was developed covering the main factors included in the literature of teaching-learning of expressivity and emotion in music. Through exploratory factor analysis three factors were identified: expressive technique (ET), emotional expression (EE), and self-learning of expressivity (SLE). Comparisons between teachers and students showed that teachers had significant higher scores in EE with no differences in ET or SLE, although the effect size for SLE was high. The three factors are proposed as a tool for the assessment of conceptions of expressivity and its learning in both teachers and advanced students of music for teaching and research objectives

Evidence of Double Phonon Excitations in ^{16}O + ^{208}Pb Reaction

The fusion cross-sections for ^{16}O + ^{208}Pb, measured to high precision, enable the extraction of the distribution of fusion barriers. This shows a structure markedly different from the single-barrier which might be expected for fusion of two doubly-closed shell nuclei. The results of exact coupled channel calculations performed to understand the observations are presented. These calculations indicate that coupling to a double octupole phonon excited state in ^{208}Pb is necessary to explain the experimental barrier distributions.Comment: 6 pages, 2 figures, To be published in the Proceedings of the FUSION 97 Conference, South Durras, Australia, March 1997 (J. Phys. G

Mid-infrared frequency comb generation via cascaded quadratic nonlinearities in quasi-phase-matched waveguides

We experimentally demonstrate a simple configuration for mid-infrared (MIR) frequency comb generation in quasi-phase-matched lithium niobate waveguides using the cascaded-$\chi^{(2)}$ nonlinearity. With nanojoule-scale pulses from an Er:fiber laser, we observe octave-spanning supercontinuum in the near-infrared with dispersive-wave generation in the 2.5--3 \text{\mu}m region and intra-pulse difference-frequency generation in the 4--5 \text{\mu}m region. By engineering the quasi-phase-matched grating profiles, tunable, narrow-band MIR and broadband MIR spectra are both observed in this geometry. Finally, we perform numerical modeling using a nonlinear envelope equation, which shows good quantitative agreement with the experiment---and can be used to inform waveguide designs to tailor the MIR frequency combs. Our results identify a path to a simple single-branch approach to mid-infrared frequency comb generation in a compact platform using commercial Er:fiber technology

Myoclonus-dystonia : distinctive motor and non-motor phenotype from other dystonia syndromes

Background: myoclonus-dystonia (M-D) due to a pathogenic variant of SGCE is an autosomal dominant inherited movement disorder. Apart from motor symptoms, psychiatric disorders are highly prevalent in patients with MD. Previous studies suggest, but never tested directly, that the type of psychiatric disorder differs between dystonia syndromes, probably related to disease specific pathology. Little is known about other non-motor symptoms (NMS) in M.D. Here, we systematically study NMS in M-D in direct comparison to other types of dystonia and healthy controls. Methods: Standardized questionnaires were used to assess type and severity of psychiatric co-morbidity, sleep problems, fatigue and quality of life. Results of M-D patients with a pathogenic variant of SGCE were compared to results of idiopathic cervical dystonia (CD) patients, dopa-responsive dystonia (DRD) patients with a pathogenic variant of GCH1 and controls. Results: We included 164 participants: 41 M-D, 51 CD, 19 DRD patients, 53 controls. Dystonia patients (M-D, CD and DRD) had an increased prevalence of psychiatric disorders compared to controls (56-74% vs. 29%). In M-D we found a significantly increased prevalence of obsessive-compulsive disorder (OCD) and psychosis compared to CD and DRD. All dystonia patients had more sleep problems (49-68% vs. 36%) and fatigue (42-73% vs. 15%) than controls. Compared to other dystonia subtypes, M-D patients reported less excessive daytime sleepiness and fatigue. Conclusion: Psychiatric comorbidity is frequent in all dystonia types, but OCD and psychosis are more common in M-D patients. Further research is necessary to elucidate underlying pathways