Preparation of circular Rydberg states in helium using the crossed fields method

Helium atoms have been prepared in the circular $|n=55,\ell=54,m_{\ell}=+54\rangle$ Rydberg state using the crossed electric and magnetic fields method. The atoms, initially travelling in pulsed supersonic beams, were photoexcited from the metastable 1s2s\,^3S_1 level to the outermost, $m_{\ell}=0$ Rydberg-Stark state with $n=55$ in the presence of a strong electric field and weak perpendicular magnetic field. Following excitation, the electric field was adiabatically switched off causing the atoms to evolve into the circular state with $m_{\ell}=+54$ defined with respect to the magnetic field quantization axis. The circular states were detected by ramped electric field ionization along the magnetic field axis. The dependence of the circular state production efficiency on the strength of the excitation electric field, and the electric-field switch-off time was studied, and microwave spectroscopy of the circular-to-circular $|55,54,+54\rangle\rightarrow|56,55,+55\rangle$ transition at $\sim38.5$~GHz was performed.Comment: 10 pages, 8 figure

Production Costs in Atlantic Fresh Fish Processing

Production costs for fresh Atlantic groundfish and scallop processing are examined using direct observation, linear regression analysis, and cost accounting. Assuming that management chooses a production technique where marginal costs are constant over a wide range of production due to management's expectation of predictable and unpredictable variation in product demand and exvessel supply, estimates of marginal cost for nonfish inputs from linear regression results and from cost accounting are compared. Also, regression results for physical yield from fish inputs are compared to estimates from the U.S. Department of Commerce. The similarity in results between these independent forms of estimation supports the maintained hypothesis of constant marginal cost over a wide range of production.Demand and Price Analysis, Environmental Economics and Policy, Food Consumption/Nutrition/Food Safety, Production Economics, Resource /Energy Economics and Policy, Risk and Uncertainty,

Examining the appeal and ascribed meanings of Complementary and Alternative Medicine (CAM) use by males: An interpretative phenomenological analysis

Men are commonly and consistently underrepresented in global depression rates, however figure predominantly in rates for substance abuse and suicide. It has been suggested that men’s under-utilisation of mental health services accounts for the discrepancy between the genders and that hegemonic masculine stereotypes have created a barrier for males in seeking help for mood disorders. The use of Complementary and Alternative Medicines (CAM) has been expanding globally, with research showing in some instances of self-diagnosed depression and anxiety, CAM is being utilised more often than mainstream health care services. The present study explored the personal meanings of males who currently use CAM in Western Australia. The objective was to examine male motivations towards CAM use and their interpretations of men’s health issues. Eight self-selected participants, from three procedure-based CAM (Yoga, Applied Kinesiology, Meditation), were interviewed using a semi-structured interview schedule. Interpretative Phenomenological Analysis was used to construct a framework for understanding the personal meanings of the participants’ experiences. Four overarching themes were identified and discussed: (1) Male depression; Experience and expression, (2) Environmental influence, (3) CAM use to develop positive mental habits over time, and (4) CAM benefits of self-awareness, self-care and self-responsibility. CAM users report positive benefits in their thoughts, moods and behaviours, however feel restricted in talking about their positive experiences among some peer groups. Conclusions are made regarding the role societal expectations play on the expression of emotions for men. Limitations of this study and future directions are discussed

CONSUMPTION AND HOUSE PRICES IN IRELAND, Quarterly Economic Commentary Autumn 2007

We examine the link between private consumption and housing wealth in Ireland. We find that until very recently the marginal propensity to consume out of housing wealth was essentially zero. This is in marked contrast to the recent evidence for other OECD countries. The evidence is robust to changes in statistical methodology. Thus we can conclude that the recent consumption growth was not financed by borrowing against housing wealth. This suggests that any decline in house prices would not cut consumption significantly

Electrically tuned Forster resonances in collisions of NH3 with Rydberg He atoms

The effects of weak electric fields on resonant energy transfer between NH3 in the X 1 A1 ground electronic state and Rydberg He atoms in triplet states with principal quantum numbers n = 36–41 have been studied in a crossed-beam apparatus. For these values of n, electric dipole transitions between the Rydberg states that evolve adiabatically to the |ns and |np states in zero electric field can be tuned into resonance with the ground-state inversion transitions in NH3 using electric fields, with energy transfer occurring via Förster resonance. In the experiments the Rydberg He atoms, traveling in pulsed supersonic beams, were prepared by resonant two-photon excitation from the metastable 1s2s 3 S1 level and crossed an effusive beam of NH3 before being detected by state-selective pulsed-electric-field ionization. The resonant-energy-transfer process was identified by monitoring changes in the ionization signal from the |ns and |np Rydberg states for each value of n. The electric-field dependence of the experimental data is in good agreement with the results of calculations in which the resonant dipole-dipole coupling between the collision partners was accounted for.

Interferometers as Probes of Planckian Quantum Geometry

A theory of position of massive bodies is proposed that results in an observable quantum behavior of geometry at the Planck scale, $t_P$. Departures from classical world lines in flat spacetime are described by Planckian noncommuting operators for position in different directions, as defined by interactions with null waves. The resulting evolution of position wavefunctions in two dimensions displays a new kind of directionally-coherent quantum noise of transverse position. The amplitude of the effect in physical units is predicted with no parameters, by equating the number of degrees of freedom of position wavefunctions on a 2D spacelike surface with the entropy density of a black hole event horizon of the same area. In a region of size $L$, the effect resembles spatially and directionally coherent random transverse shear deformations on timescale $\approx L/c$ with typical amplitude $\approx \sqrt{ct_PL}$. This quantum-geometrical "holographic noise" in position is not describable as fluctuations of a quantized metric, or as any kind of fluctuation, dispersion or propagation effect in quantum fields. In a Michelson interferometer the effect appears as noise that resembles a random Planckian walk of the beamsplitter for durations up to the light crossing time. Signal spectra and correlation functions in interferometers are derived, and predicted to be comparable with the sensitivities of current and planned experiments. It is proposed that nearly co-located Michelson interferometers of laboratory scale, cross-correlated at high frequency, can test the Planckian noise prediction with current technology.Comment: 23 pages, 6 figures, Latex. To appear in Physical Review