Plant connectivity underlies plant-pollinator-exploiter distributions in Ficus petiolaris and associated pollinating and non-pollinating fig wasps

Peer reviewedPostprin

Observation of a possible superflare on Proxima Centauri

We report the observation on UT 2017 July 1 of an unusually powerful flare detected in near-infrared continuum photometry of Proxima Centauri. During a campaign monitoring the star for possible exoplanet transits, we identified an increase in Sloan i' flux leading to an observed peak at BJD 2457935.996 that was at least 10 per cent over pre-flare flux in this band. It was followed by a two-component rapid decline in the first 100 s that became a slower exponential decay with time constant of 1350 s. A smaller flare event 1300 s after the first added an incremental peak flux increase of 1 per cent of pre-flare flux. Since the onset of the flare was not fully time resolved at a cadence of 62 s, its actual peak value is unknown but greater than the time average over a single exposure of 20 s. The i' band is representative of broad optical and near-IR continuum flux over which the integrated energy of the flare is 100 times the stellar luminosity. This meets the criteria that established the concept of superflares on similar stars. The resulting implied ultraviolet flux and space weather could have had an extreme effect on the atmospheres of planets within the star's otherwise habitable zone

A twin-mirrored galvanometer laser light sheet generator

A galvanometer mirror-based laser light sheet system has been developed for use in the Basic Aerodynamics Research Tunnel at NASA Langley. This system generates and positions single or multiple light sheets over aeronautical research models being tested in the low speed tunnel. This report describes a twin mirrored galvanometer laser light sheet generator and shows typical light sheet arrangements in use. With this system, illumination of smoke entrained in the flow over a delta wing model reveals the vortical flow produced by the separation of the flow at the leading edge of the model. The light sheet system has proven to be very adaptable and easy to use in sizing and positioning light sheets in wind tunnel applications

Nonlinear Sideband Cooling to a Schr\"odinger Cat State of Motion

The ability to prepare a macroscopic mechanical resonator into a quantum superposition state is an outstanding goal of cavity optomechanics. Here we propose a technique to generate Schr\"odinger cat states of motion using the intrinsic nonlinearity of a dispersive optomechanical interaction. By applying a bichromatic drive to an optomechanical cavity, our protocol enhances the inherent second-order processes of the system, inducing the requisite two-phonon dissipation. We show that this nonlinear sideband cooling technique can dissipatively engineer a mechanical resonator into a Schr\"odinger cat state, which we verify using the full Hamiltonian and an adiabatically reduced model. While the fidelity of the cat state is maximized in the single-photon, strong-coupling regime, we demonstrate that Wigner negativity persists even for weak coupling. Finally, we show that our cat state generation protocol is robust to significant thermal decoherence of the mechanical mode, indicating that such a procedure may be feasible for near-term experimental systems.Comment: 6 pages, 4 figures with additional supplementary information (12 pages, 2 figures

THE ECONOMIC CONSEQUENCES OF EUROPEAN UNION A Symposium on Some Policy Aspects. THE ECONOMIC AND SOCIAL RESEARCH INSTITUTE, DUBLIN, 1986

The papers published here, together with the Matthews paper, address some of the economic questions on which discussion of further European integration should be based. Will European prosperity bring Irish prosperity? Does a free market threaten traditional Irish industry, or aid new Irish industry, or both? How can a small peripheral economy survive and prosper in a monetary union? How much autonomy does an Irish government at present enjoy in monetary and fiscal policy? Are Ireland’s interests close to the Community average? Questions such as these are asked by politicians, who expect economists to answer them; economists tend to react by asking further questions, by demanding quantitative data on which to base their assessments. It is one of the positive points of these papers that the economists have been willing to be drawn out on some of these current issues of political economy, even if others remain to be tackled. I believe that the burden of these papers does not suggest any reason for doubting that in the long term it is in Ireland’s interest that the Community should be economically and politically strong, and that Ireland should be a full partner in that Community

On-Chip Cavity Optomechanical Coupling

On-chip cavity optomechanics, in which strong co-localization of light and mechanical motion is engineered, relies on efficient coupling of light both into and out of the on-chip optical resonator. Here we detail our particular style of tapered and dimpled optical fibers, pioneered by the Painter group at Caltech, which are a versatile and reliable solution to efficient on-chip coupling. First, a brief overview of tapered, single mode fibers is presented, in which the single mode cutoff diameter is highlighted. The apparatus used to create a dimpled tapered fiber is then described, followed by a comprehensive account of the procedure by which a dimpled tapered fiber is produced and mounted in our system. The custom-built optical access vacuum chambers in which our on-chip optomechanical measurements are performed are then discussed. Finally, the process by which our optomechanical devices are fabricated and the method by which we explore their optical and mechanical properties is explained. It is our expectation that this manuscript will enable the novice to develop advanced optomechanical experiments.Comment: 31 pages, 9 figure