Imaging phonon eigenstates and elucidating the energy storage characteristics of a honeycomb-lattice phononic crystal cavity

We extend gigahertz time-domain imaging to a wideband investigation of the eigenstates of a phononic crystal cavity. Using omnidirectionally excited phonon wave vectors, we implement an ultrafast technique to experimentally probe the two-dimensional acoustic field inside and outside a hexagonal cavity in a honeycomb-lattice phononic crystal formed in a microscopic crystalline silicon slab, thereby revealing the confinement and mode volumes of phonon eigenstates-some of which are clearly hexapole in character-lying both inside and outside the phononic-crystal band gap. This allows us to obtain a quantitative measure of the spatial acoustic energy storage characteristics of a phononic crystal cavity. We also introduce a numerical approach involving toneburst excitation and the monitoring of the acoustic energy decay together with the integral of the Poynting vector to calculate the Q factor of the principal in-gap eigenmode, showing it to be limited by ultrasonic attenuation rather than by phonon leakage to the surrounding region.

A matter of taste: the adverse effect of pollen compounds on the pre-ingestive gustatory experience of sugar solutions for honeybees

In addition to sugars, nectar contains multiple nutrient compounds in varying concentrations, yet little is known of their effect on the reward properties of nectar and the resulting implications for insect behaviour. We examined the pre-ingestive responses of honeybees to sucrose solutions containing a mix of pollen compounds, the amino acids proline or phenylalanine, or known distasteful substances, quinine and salt. We predicted that in taste and learning assays, bees would respond positively to the presence of nutrient compounds in a sucrose solution. However, bees’ proboscis extension responses decreased when their antennae were stimulated with pollen- or amino acid-supplemented sucrose solutions. Compared to pure sucrose, bees exhibited worse acquisition when conditioned to an odour with pollen-supplemented sucrose as the unconditioned stimulus. Such learning impairment was also observed with quinine-containing sucrose solutions. Our results suggest that bees can use their antennae to detect pollen compounds in floral nectars. Depending on the type and concentrations of compounds present, this may result in nectar being perceived as distasteful by bees, making it less effective in reinforcing the learning of floral cues. Such reward devaluation might be adaptive in cases where plants benefit from regulating the frequency of bee visitation.

‘Abd al-Qādir al-Marāghī and ‘Alī b. Muḥammad Binā'ī: two fifteenth-century examples of notation. Part 1: Text

Given the dependence on aural transmission in the pre-modern musical traditions of the Islamic Middle East it is not at all surprising to find that compositions were hardly ever notated. If there is a typical method of recording the repertoire it is to be identified, rather, in the song-text anthology, which may provide quite detailed indications of formal structure but contains no melodic specification beyond identifying the principal mode of the piece and serves, therefore, as a textual prompt. Indeed, if we disregard as wholly exceptional the rich documentation of the Ottoman repertoire provided by the extensive collections of notated pieces made by ‘Alī Ufḳī and Cantemir, we find for the seventeenth and earlier centuries just one or two not very informative craps recorded by European observers and the occasional samples provided in theoretical treatises.

Rehabilitation after heart transplantation: the Australian experience

This study was designed to assess aspects of the quality of life and rehabilitation of heart transplant recipients who had transplantations at St. Vincent's Hospital, New South Wales, Australia, between February 1984 and March 1987. Factors determining return to full-time employment were delineated. A questionnaire was sent to 51 recipients. The response rate was 92%. The questionnaire measured employment status and satisfaction with family, social, marital, and sexual life. Financial status, exercise ability, and participation in daily activities were also assessed. Analysis showed that 53% of recipients had returned to either full-time or part-time employment, home duties, or full-time study. A further 28% were receiving a pension, 9% had chosen voluntary retirement, 6% were receiving unemployment benefits, and 4% were getting paid leave. Ability to exercise was improved for 77% of recipients and remained the same for another 14%. Financial status was unchanged for 45% and improved for 17%. Thirty-eight percent believed that they were worse off financially. Ratings of social, family, and marital life showed nearly complete or complete satisfaction in most cases. Satisfaction with sex life was less favorable. Comparison of the group who had returned to full-time employment with the group receiving a pension identified two variables of work status--length of time since transplantation and employment status before transplantation. There were also some differences between the two groups on quality of life ratings.