A series solution and a fast algorithm for the inversion of the spherical mean Radon transform

An explicit series solution is proposed for the inversion of the spherical mean Radon transform. Such an inversion is required in problems of thermo- and photo- acoustic tomography. Closed-form inversion formulae are currently known only for the case when the centers of the integration spheres lie on a sphere surrounding the support of the unknown function, or on certain unbounded surfaces. Our approach results in an explicit series solution for any closed measuring surface surrounding a region for which the eigenfunctions of the Dirichlet Laplacian are explicitly known - such as, for example, cube, finite cylinder, half-sphere etc. In addition, we present a fast reconstruction algorithm applicable in the case when the detectors (the centers of the integration spheres) lie on a surface of a cube. This algorithm reconsrtucts 3-D images thousands times faster than backprojection-type methods

Probe for the strong parity violation effects at RHIC with three particle correlations

In non-central relativistic heavy ion collisions, \P-odd domains, which might be created in the process of the collision, are predicted to lead to charge separation along the system orbital momentum \cite{Kharzeev:2004ey}. An observable, \P-even, but directly sensitive to the charge separation effect, has been proposed in \cite{Voloshin:2004vk} and is based on 3-particle mixed harmonics azimuthal correlations. We report the STAR measurements using this observable for Au+Au and Cu+Cu collisions at $\sqrt{s_{NN}}$=200 and 62 GeV. The results are reported as function of collision centrality, particle separation in rapidity, and particle transverse momentum. Effects that are not related to parity violation but might contribute to the signal are discussed.Comment: 4 pages, Quark Matter 2008 Poster proceeding

Effects of solar wind magnetosphere coupling recorded at different geomagnetic latitudes: Separation of directly-driven and storage/release systems

The effect on geomagnetic activity of solar wind speed, compared with that of the strength of the interplanetary magnetic field, differs with geomagnetic latitude. In this study we construct a new index based on monthly standard deviations in the H-component of the geomagnetic field for all geomagnetic latitudes. We demonstrate that for this index the response at auroral regions correlates best with interplanetary coupling functions which include the solar wind speed while mid- and low-latitude regions respond to variations in the interplanetary magnetic field strength. These results are used to isolate the responsible geomagnetic current systems

Self-Reported Supervisory Behavior and Belief vs. Actual Observations of Caregiver Behavior at Beaches

This study examined self-reported supervisory behaviours of caregivers at beaches and ascertained whether self-reported supervision reflects observed behaviour. Observations were conducted of caregiver/child pairs at 18 Australian beaches, with questionnaires subsequently completed by caregivers. Caregivers identified visual contact as essential for close supervision and proximity a key determinant in distinguishing supervision and close supervision. Supervisory behaviour was associated with child age, whilst lifeguard patrol had no effect on supervision. All supervision statements from the PSAPQ-BEACH were associated with supervision. Only three statements were significant independent predictors of supervision. Comparisons suggest caregivers’ self-reported supervisory behaviour reflects actual supervision. As this is the first study of its kind, it is essential that further prospective research using mixed-method approaches build on this information

Acute military psychiatric casualties from the war in Iraq

Background: The view that most military personnel evacuated from war zones are suffering from combat stress reactions, or are otherwise traumatised by the horrors of war, has an impact on all aspects of military psychiatry. Aims: To delineate the reasons for psychiatric aeromedical evacuation from Iraq from the start of build-up of UK forces in January 2003 until the end of October that year, 6 months after the end of formal hostilities. Method: A retrospective study was conducted of field and in-patient psychiatric assessments of 116 military personnel evacuated to the UK military psychiatric in-patient facility in Catterick Garrison. Results: Evacuees were mainly non-combatants (69%). A significant proportion were in reserve service (21%) and had a history of contact with mental health services (37%). Only 3% had a combat stress reaction. In over 85% of cases evacuation was for low mood attributed to separation from friends or family, or difficulties adjusting to the environment. Conclusions: These findings have implications especially for screening for suitability for deployment, and for understanding any longer-term mental health problems arising in veterans from Iraq

Sunspot observations from the SOUP instrument on Spacelab 2

A series of white light images obtained by the SOUP instrument on Spacelab 2 of active region 4682 on August 5, 1985 were analyzed in the area containing sunspots. Although the umbra of the spot is underexposed, the film is well exposed in the penumbral regions. These data were digitally processed to remove noise and to separate p-mode oscillations from low velocity material motions. The results of this preliminary investigation include: (1) proper motion measurements of a radial outflow in the photospheric granulation pattern just outside the penumbra; (2) discovery of occasional bright structures (streakers) that appear to be ejected outward from the penumbra; (3) broad dark clouds moving outward in the penumbra in addition to the well known bright penumbral grains moving inward; (4) apparent extensions and contractions of penumbral filaments over the photosphere; and (5) observation of a faint bubble or loop-like structure which seems to expand from two bright penumbral filaments into the photosphere

Some observations on the structure of the filamentous particles of several plant viruses

RESP-572