688 research outputs found
Towards Laser Driven Hadron Cancer Radiotherapy: A Review of Progress
It has been known for about sixty years that proton and heavy ion therapy is
a very powerful radiation procedure for treating tumours. It has an innate
ability to irradiate tumours with greater doses and spatial selectivity
compared with electron and photon therapy and hence is a tissue sparing
procedure. For more than twenty years powerful lasers have generated high
energy beams of protons and heavy ions and hence it has been frequently
speculated that lasers could be used as an alternative to RF accelerators to
produce the particle beams necessary for cancer therapy. The present paper
reviews the progress made towards laser driven hadron cancer therapy and what
has still to be accomplished to realise its inherent enormous potential.Comment: 40 pages, 24 figure
Transformation and slippage in co-production ambitions for global technology development: the case of gene drive
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordCo-production is an increasingly popular framework for knowledge generation, evaluation
and decision making. Despite its potential to open up decisions and practices to the input of
others, co-production regularly falls short of its transformative ambitions. Through
documentary analysis, we investigate the meaning and dynamics of co-production as it
stretches beyond the local into global research and technology spaces. We find that in the
case of global gene drive, the meaning of co-production is extended in novel ways and
underpinned by new possibilities for meaningful transformation. At the same time, we also
identify a simultaneous resurfacing of reductive framings of collaboration. In the paper we
present ‘slippage’ as a useful heuristic in helping to understand why co-production fails. We
argue that if co-production in these new spaces is to achieve its transformative ambitions,
there is a need to engage with new and entrenched knowledge hierarchies that contribute to
this slippage.British Academ
In Situ Characterisation of Permanent Magnetic Quadrupoles for focussing proton beams
High intensity laser driven proton beams are at present receiving much
attention. The reasons for this are many but high on the list is the potential
to produce compact accelerators. However two of the limitations of this
technology is that unlike conventional nuclear RF accelerators lasers produce
diverging beams with an exponential energy distribution. A number of different
approaches have been attempted to monochromise these beams but it has become
obvious that magnetic spectrometer technology developed over many years by
nuclear physicists to transport and focus proton beams could play an important
role for this purpose. This paper deals with the design and characterisation of
a magnetic quadrupole system which will attempt to focus and transport
laser-accelerated proton beams.Comment: 20 pages, 42 figure
Orbital electron capture by the nucleus
The theory of nuclear electron capture is reviewed in the light of current understanding of weak interactions. Experimental methods and results regarding capture probabilities, capture ratios, and EC/Beta(+) ratios are summarized. Radiative electron capture is discussed, including both theory and experiment. Atomic wave function overlap and electron exchange effects are covered, as are atomic transitions that accompany nuclear electron capture. Tables are provided to assist the reader in determining quantities of interest for specific cases
Photonuclear physics - Laser light splits atom
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62874/1/404239a0.pd
A concise patient reported outcome measure for people with aphasia: the aphasia impact questionnaire 21
Background: There are many validated and widely used assessments within aphasiology. Few, however, describe language and life with aphasia from the perspective of the person with aphasia. Across healthcare, patient experience and user involvement are increasingly acknowledged as fundamental to person-centred care. As part of this movement, Patient Reported Outcome Measures (PROMs) are being used in service evaluation and planning.
Aims: This paper reports the quantitative aspects of a mixed methods study that developed and validated a concise PROM, the Aphasia Impact Questionnaire (AIQ), co-produced with People with Aphasia (PWA).
Methods & Procedures: The AIQ was developed within the social model of disability and all stages of the development of the AIQ were performed in partnership with PWA. It was adapted from a pre-existing and lengthier PROM for PWA, the Communication Disability Profile. The first iterations of the AIQ focused on domains of communication, participation and well-being/emotional state. Subsequently the AIQ was extended to include additional items relating to reading and writing (AIQ-21). The research design was iterative. Initially, concurrent validity, internal consistency, and sensitivity of the AIQ-prototype were obtained. The AIQ-prototype was modified to become the AIQ-21. Statistical testing with a new group of PWA was performed, investigating internal consistency and concurrent validity of the AIQ-21.
Outcomes & Results: Results for both the AIQ-prototype and AIQ-21 showed statistically significant concurrent validity and good internal consistency. Repeated measurement using the AIQ-prototype demonstrated statistically significant change after PWA accessed a community intervention.
Conclusions: The AIQ-21 is a PROM that has great potential to be one of the core set of aphasia tests for clinical and research use. Results can be used alongside language assessment to enable person-centred goal setting and partnership working for people with aphasia
Theory of noise suppression in {\Lambda}-type quantum memories by means of a cavity
Quantum memories, capable of storing single photons or other quantum states
of light, to be retrieved on-demand, offer a route to large-scale quantum
information processing with light. A promising class of memories is based on
far-off-resonant Raman absorption in ensembles of -type atoms. However
at room temperature these systems exhibit unwanted four-wave mixing, which is
prohibitive for applications at the single-photon level. Here we show how this
noise can be suppressed by placing the storage medium inside a moderate-finesse
optical cavity, thereby removing the main roadblock hindering this approach to
quantum memory.Comment: 10 pages, 3 figures. This paper provides the theoretical background
to our recent experimental demonstration of noise suppression in a
cavity-enhanced Raman-type memory ( arXiv:1510.04625 ). See also the related
paper arXiv:1511.05448, which describes numerical modelling of an atom-filled
cavity. Comments welcom
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