The photons payload, G-494: A learning experience

PHOTONS (Photometric Thermospheric Oxygen Nightglow Study) is an optical remote sensing payload developed for Get Away Special (GAS) flight by the National Research Council of Canada. The device is extremely sensitive and is suitable for making measurements of low intensity, aeronomically generated atmospheric emissions in the nadir and the limb and of Shuttle ram glow. The unit uses a sealed canister and UV transmitting viewing ports. During the flight of STS 61-C, PHOTONS received one hour of operation and aeronomic observations were made. Good diagnostic data were obtained and the science part of the experiment malfunctioned. Post flight inspection revealed that the payload was in perfect working order except for total failure of the photomultiplier detectors. The experiment and the payload are described and the flight results are discussed along with the cause of the malfunctions. It is shown that enough was learned from the flight diagnostic data and about the cause of the malfunction to conclude that the engineering flight was successful and that subsequent flight of the PHOTONS payload will be productive

On the variability of I(7620 Å)/I(5577 Å) in low altitude aurora

International audienceAn auroral electron excitation model, combined with simple equilibrium neutral and ion chemistry models, is used to investigate the optical emission processes and height profiles of I(5577 Å) and I(7620 Å) in the 90 to 100 km altitude region. It is shown that the apparent discrepancies between ground-based and rocket-borne auroral observations of the I(7620 Å)/I(5577 Å) ratio are due to the extreme height variation of this intensity ratio in the 90 to 100 km region

Effective Behaviour Management Strategies for Australian Aboriginal and Torres Strait Islander Students: A Literature Review

This paper reports findings from a systematic literature review conducted to identify effective behaviour management strategies which create a positive learning environment for Aboriginal and Torres Strait Islander students. The search criteria employed resulted in 103 documents which were analysed in response to this focus. Results identified eight themes underpinning strategies for effective behaviour management. Despite the suggested actions, the review highlights that little empirical research has been conducted to validate effective classroom behaviour management strategies; strategies which may also be used to inform teacher education. Considering the high representation of Indigenous students in statistics related to behaviour infringements and other negative school outcomes, this review affirms the urgent need for research to investigate and establish empirically what constitutes effective behaviour management for Indigenous students

Social and structural conditions for the avoidance of advance care planning in neuro-oncology: a qualitative study

BACKGROUND: Primary brain tumours newly affect >260 000 people each year worldwide. In the UK, every year >10 000 people are diagnosed with a brain tumour while >5000 die annually from the disease. Prognoses are poor, cognitive deterioration common and patients have prolonged palliative needs. Advance care planning (ACP) may enable early discussion of future care decisions. Although a core commitment in the UK healthcare strategy, and the shared responsibility of clinical teams, ACP appears uncommon in practice. Evidence around ACP practice in neuro-oncology is limited. OBJECTIVES: We aimed to elicit key social and structural conditions contributing to the avoidance of ACP in neuro-oncology. DESIGN: A cross-sectional qualitative study design was used. SETTING: One tertiary care hospital in the UK. PARTICIPANTS: Fifteen healthcare professionals working in neuro-oncology participated in this study, including neuro-oncologists, neurosurgeons, clinical nurse specialists, allied healthcare professionals and a neurologist. METHOD: Semi-structured interviews were conducted with participants to explore their assumptions and experiences of ACP. Data were analysed thematically using the well-established framework method. RESULTS: Participants recognised the importance of ACP but few had ever completed formal ACP documentation. We identified eight key factors, which we suggest comprise three main conditions for avoidance: (1) difficulties being a highly emotive, time-intensive practice requiring the right 'window of opportunity' and (2) presence and availability of others; (3) ambiguities in ACP definition, purpose and practice. Combined, these created a 'culture of shared avoidance'. CONCLUSION: In busy clinical environments, 'shared responsibility' is interpreted as 'others' responsibility' laying the basis for a culture of avoidance. To address this, we suggest a 'generalists and specialists' model of ACP, wherein healthcare professionals undertake particular responsibilities. Healthcare professionals are already adopting this model informally, but without formalised structure it is likely to fail given a tendency for people to assume a generalist role

Polarization of Tau Leptons Produced in Quasielastic Neutrino--Nucleon Scattering

A numerical analysis of the polarization vector of tau leptons produced through quasielastic neutrino and antineutrino interactions with free nucleons is given with two models for vector electromagnetic form factors of proton and neutron. The impact of G parity violating axial and vector second-class currents is investigated by applying a simple heuristic model for the induced scalar and tensor form factors.Comment: Thesis of a talk given at the 8th Scientific Conference (SCYSS-04), Dubna, Russia, 2 - 6 Feb 2004. 11 pages, 6 figures; added references, figures and discussion; conclusions unchange

Plasma Physics

Contains reports on five research projects.United States Atomic Energy Commission (Contract AT(30-1)-1842)Project MACAdvanced Research Agency, Department of Defense, under Office of Naval Research Contract Nonr-4102(01

Pions in the nuclear medium and Drell-Yan scattering

We investigate the modification of the pion-cloud in the nuclear medium and its effect on the nuclear Drell-Yan process. The pion's in-medium self-energy is calculated in a self-consistent delta-hole model, with particle-hole contribution also included. Both the imaginary and real part of the pion's and delta's self-energy are taken into account and related through a dispersion relation assuring causality. The resulting in-medium pion light-cone momentum distribution shows only a slight enhancement compared to the one of the free nucleon. As a consequence the ratio of the cross-section for Drell-Yan scattering on nuclear matter and nucleonic target is close to unity in agreement with experiment.Comment: 33 pages, Latex with epsf, figures included, to appear in Phys. Rev.

The Roles of Vertical Advection and Eddy Diffusion in the Equatorial Mesospheric Semi-Annual Oscillation (MSAO)

Observations of the mesospheric semi-annual oscillation (MSAO) in the equatorial region have been reported dating back several decades. Seasonal variations in both species densities and airglow emissions are well documented. The extensive observations available offer an excellent case study for comparison with model simulations. A broad range of MSAO measurements is summarised with emphasis on the 80-100 km region. The objective here is not to address directly the complicated driving forces of the MSAO, but rather to employ a combination of observations and model simulations to estimate the limits of some of the underlying dynamical processes. Photochemical model simulations are included for near-equinox and near-solstice conditions, the two times with notable differences in the observed MSAO parameters. Diurnal tides are incorporated in the model to facilitate comparisons of observations made at different local times. The roles of water vapour as the driver species and ozone as the response species are examined to test for consistency between the model results and observations. The simulations suggest the interactions between vertical eddy diffusion and background vertical advection play a significant role in the MSAO phenomenon. Further, the simulations imply there are rigid limits on vertical advection rates and eddy diffusion rates. For August at the Equator, 90 km altitude, the derived eddy diffusion rate is approximately 1 x 106 cm2 s-1 and the vertical advection is upwards at 0.8 cm s-1. For April the corresponding values are 4 x 105 cm2 s-1 and 0.1 cm s-1. These results from the current 1-D model simulations will need to be verified by a full 3-D simulation. Exactly how vertical advection and eddy diffusion are related to gravity wave momentum as discussed by Dunkerton (1982) three decades ago remains to be addressed

Resonance production by neutrinos: I. J=3/2 Resonances

The article contains general formulas for the production of J=3/2 resonances by neutrinos and antineutrinos. It specializes to the P_{33}(1232) resonance whose form factors are determined by theory and experiment and then are compared with experimental results at low and high energies. It is shown that the minimum in the low Q^2 region is a consequence of a combined effect from the vanishing of the vector form factors, the muon mass and Pauli blocking. Several improvements for the future investigations are suggested.Comment: 10 pages, LaTeX, misprints corrected, 1 reference adde