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Biomedical subjects

J Gallacher

Publications and source records attributed to J Gallacher.

16 recordsLinked to original sources
PubMed2006

The generation of mono-energetic electron beams from ultrashort pulse laser-plasma interactions.

The physics of the interaction of high-intensity laser pulses with underdense plasma depends not only on the interaction intensity but also on the laser pulse length. We show experimentally that as intensities are increased beyond 10(20) W cm(-2) the peak electron acceleration increases beyond that which can be produced from single stage plasma wave acceleration and it is likely that direct laser acceleration mechanisms begin to play an important role. If, alternatively, the pulse length is reduced such that it approaches the plasma period of a relativistic electron plasma wave, high-power interactions at much lower intensity enable the generation of quasi-mono-energetic beams of relativistic electrons.

Journal Article↗
PubMed2006

Radiation sources based on laser-plasma interactions.

Plasma waves excited by intense laser beams can be harnessed to produce femtosecond duration bunches of electrons with relativistic energies. The very large electrostatic forces of plasma density wakes trailing behind an intense laser pulse provide field potentials capable of accelerating charged particles to high energies over very short distances, as high as 1GeV in a few millimetres. The short length scale of plasma waves provides a means of developing very compact high-energy accelerators, which could form the basis of compact next-generation light sources with unique properties. Tuneable X-ray radiation and particle pulses with durations of the order of or less than 5fs should be possible and would be useful for probing matter on unprecedented time and spatial scales. If developed to fruition this revolutionary technology could reduce the size and cost of light sources by three orders of magnitude and, therefore, provide powerful new tools to a large scientific community. We will discuss how a laser-driven plasma wakefield accelerator can be used to produce radiation with unique characteristics over a very large spectral range.

Journal Article↗
PubMed1997

Using accreditation of prior learning and accreditation of prior experiential learning for entry on to the BSc in Medical Illustration.

The Accreditation of Prior Learning (APL) and Accreditation of Prior Experiential Learning (APEL) scheme described in this paper has been prepared following discussions between the Institute of Medical Illustrators (IMI) and Glasgow Caledonian University (GCU), departments of Learning and Educational Development and Biological Sciences. The scheme gives specific academic credit under the Scottish Credit Accumulation and Transfer (SCOTCAT) scheme for learning gained from experience, allowing access onto the Bachelor of Science Degree (BSc) in Medical Illustration to potential students who do not have the required Higher National Diploma (HND) or equivalent entry qualification. The need, rationale and structure of the scheme are described.

Accreditation↗
PubMed1993

Road traffic noise, noise sensitivity and psychological disorder.

The relationship between traffic noise exposure and psychological morbidity was assessed using the population-based Caerphilly Collaborative Survey of 2398 men from Caerphilly, South Wales. The findings showed that traffic noise exposure levels were strongly associated with annoyance to noise. Noise-sensitive men were more likely to be highly annoyed by noise exposure than less noise-sensitive men. There was no direct association between noise exposure level and psychological morbidity but there were provocative interactions with noise sensitivity. The role of noise sensitivity is discussed as an indicator of vulnerability to environmental stressors and a measure of negative affectivity and over-reporting.

Cohort Studies↗
PubMed1993

Road traffic noise, noise sensitivity and psychological disorder.

The relationship between traffic noise exposure and psychological morbidity was assessed using the population-based Caerphilly Collaborative Survey of 2398 men from Caerphilly, South Wales, UK. The findings showed that annoyance to noise was strongly associated with traffic noise exposure levels. Men with noise sensitivity were more likely to be highly annoyed by noise exposure than men with less noise sensitivity. There was no direct association between noise exposure level and psychological morbidity until the results were stratified by noise sensitivity. This revealed a gradient of increasing psychological morbidity with increasing noise level in the lower two tertiles of noise sensitivity. No gradient was found in the highest tertile of noise sensitivity. The role of noise sensitivity is argued to be either an indicator of vulnerability to environmental stressors or a measure of overreporting.

Anxiety Disorders↗
PubMed1990

Towards a state measure of Type A behaviour.

To investigate the feasibility of developing a measure of state Type A behaviour, a random sample of 95 men aged 40-64 years attended a clinic at which Type A behaviour was assessed using the Structured Interview (Rosenman, 1978). Upon completion of the Structured Interview, subjects were administered a 65-item adjective checklist to describe their experience of the interview. Discriminant function analysis of adjective ratings on Structured Interview classification identified 15 adjectives which allowed 83 per cent correct classification. The limitation of these data includes the small sample size and the uniqueness of the Structured Interview situation. Nevertheless, these data provide encouragement that a robust and versatile measure of state Type A could be developed. Comparisons between various measures of trait Type A behaviour are also reported.

Adult↗