703 research outputs found
Examining the role of Scotland’s telephone advice service (NHS 24) for managing health in the community : analysis of routinely collected NHS 24 data
Date of Acceptance: 15/06/2015 Funding This work was supported by the Chief Scientist Office, ScottishExecutive (grant no. CZH/4/692). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.Peer reviewedPublisher PD
Factorizing -matrices and the XXZ spin-1/2 chain: A diagrammatic perspective
Using notation inherited from the six-vertex model, we construct diagrams
that represent the action of the factorizing -matrices associated to the
finite length XXZ spin-1/2 chain. We prove that these -matrices factorize
the tensor corresponding with elements of the permutation
group. We consider in particular the diagram for the tensor , which cyclically permutes the spin chain. This leads us to a diagrammatic
construction of the local spin operators and in terms of
the monodromy matrix operators.Comment: 26 pages, extra references added, typographical errors correcte
Twisting Flux Tubes as a cause of Micro-Flaring Activity
High-cadence optical observations of an H-alpha blue-wing bright point near
solar AR NOAA 10794 are presented. The data were obtained with the Dunn Solar
Telescope at the National Solar Observatory/Sacramento Peak using a newly
developed camera system, the Rapid Dual Imager. Wavelet analysis is undertaken
to search for intensity-related oscillatory signatures, and periodicities
ranging from 15 to 370 s are found with significance levels exceeding 95%.
During two separate microflaring events, oscillation sites surrounding the
bright point are observed to twist. We relate the twisting of the oscillation
sites to the twisting of physical flux tubes, thus giving rise to reconnection
phenomena. We derive an average twist velocity of 8.1 km/s and detect a peak in
the emitted flux between twist angles of 180 and 230 degrees.Comment: 8 pages, 10 figure
Oculomotor rehearsal in visuospatial working memory
The neural and cognitive mechanisms of spatial working memory are tightly coupled with the systems that control eye movements, but the precise nature of this coupling is not well understood. It has been argued that the oculomotor system is selectively involved in rehearsal of spatial but not visual material in visuospatial working memory. However, few studies have directly compared the effect of saccadic interference on visual and spatial memory, and there is little consensus on how the underlying working memory representation is affected by saccadic interference. In this study we aimed to examine how working memory for visual and spatial features is affected by overt and covert attentional interference across two experiments. Participants were shown a memory array, then asked to either maintain fixation or to overtly or covertly shift attention in a detection task during the delay period. Using the continuous report task we directly examined the precision of visual and spatial working memory representations and fit psychophysical functions to investigate the sources of recall error associated with different types of interference. These data were interpreted in terms of embodied theories of attention and memory and provide new insights into the nature of the interactions between cognitive and motor systems
Precision in spatial working memory examined with mouse pointing
The capacity of visuospatial working memory (VSWM) is limited. However, there is continued debate surrounding the nature of this capacity limitation. The resource model (Bays et al., 2009) proposes that VSWM capacity is limited by the precision with which visuospatial features can be retained. In one of the few studies of spatial working memory, Schneegans and Bays (2016) report that memory guided pointing responses show a monotonic decrease in precision as set size increases, consistent with resource models. Here we report two conceptual replications of this study that use mouse responses rather than pointing responses. Overall results are consistent with the resource model, as there was an exponential increase in localisation error and monotonic increases in the probability of misbinding and guessing with increases in set size. However, an unexpected result of Experiment One was that, unlike Schneegans and Bays (2016), imprecision did not increase between set sizes of 2 and 8. Experiment Two replicated this effect and ruled out the possibility that the invariance of imprecision at set sizes greater than 2 was a product of oculomotor strategies during recall. We speculate that differences in imprecision are related to additional visuomotor transformations required for memory-guided mouse localisation compared to memory-guided manual pointing localisation. These data demonstrate the importance of considering the nature of the response modality when interpreting VSWM data
Discovery of spatial periodicities in a coronal loop using automated edge-tracking algorithms
A new method for automated coronal loop tracking, in both spatial and temporal domains, is presented. Applying this technique to TRACE data, obtained using the 171 Å filter on 1998 July 14, we detect a coronal loop undergoing a 270 s kink-mode oscillation, as previously found by Aschwanden et al. However, we also detect flare-induced, and previously unnoticed, spatial periodicities on a scale of 3500 km, which occur along the coronal loop edge. Furthermore, we establish a reduction in oscillatory power for these spatial periodicities of 45% over a 222 s interval. We relate the reduction in detected oscillatory power to the physical damping of these loop-top oscillations
Renewing an undergraduate science curriculum for the 21st century
IntroductionThe rapid pace of technological advancement, globalisation, and complex socio-economic challenges facing 21st-century society necessitates a rethinking of undergraduate science education. Undergraduate science curriculum reform is essential to prepare students for the demands of the modern workforce in an ever-changing world. Accordingly, in Trinity College Dublin (the University of Dublin), the oldest science degree course in Ireland was intensively reviewed and redeveloped between 2014 and 2021. This study aims to collate and disseminate the knowledge acquired by university staff through the experience of undertaking a major science curriculum redevelopment.MethodsNine senior staff members closely involved with the redevelopment were interviewed about why the curriculum reform was necessary, what it had achieved, and how the process could have been improved.ResultsThe reasons behind the curriculum changes are described and placed in the context of contemporary pedagogical research. Reflections from the academic and administrative staff involved in the redevelopment process are presented, emphasising the challenges and opportunities that emerged from that process.DiscussionRecommendations for other universities undertaking similar reforms are included. Aligning undergraduate science curriculum reform with the needs of 21st-century society is vital for ensuring that science graduates are well-prepared to make positive contributions to a sustainable future
On factorizing -matrices in and spin chains
We consider quantum spin chains arising from -fold tensor products of the
fundamental evaluation representations of and .
Using the partial -matrix formalism from the seminal work of Maillet and
Sanchez de Santos, we derive a completely factorized expression for the
-matrix of such models and prove its equivalence to the expression obtained
by Albert, Boos, Flume and Ruhlig. A new relation between the -matrices and
the Bethe eigenvectors of these spin chains is given.Comment: 30 page
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