196,597 research outputs found
End-of-2021 stocktake update.
No full textCorrespondenceMichael Weightman, Tuan Anh Bui and Oliver D, Arcy Robertso
Introducing trainee editors and The Thought Broadcast podcast: Stepping forward for trainee research
No full textTrainee EditorialMichael Weightman, Tuan Anh Bui, Oliver D’Arcy Robertso
Stocktake of Australasian Psychiatry's training resources
No full textObjective: To identify all past publications from Australasian Psychiatry with subject matter particularly relevant for trainees. The results of such a search could then be collated into an easily accessible resource available to trainees and their supervisors. Method: An electronic search of the journal’s back catalogue was conducted. Results: Eighty-seven articles published on subjects particularly relevant for trainees were discovered from within Australasian Psychiatry. In particular, multiple useful resources were identified on the topics of the scholarly project and formulation skills. Conclusions: Australasian Psychiatry has published a wealth of literature that is likely to be of significant benefit for trainees as they work their way through the Royal Australian and New Zealand College of Psychiatrists training programme.Michael Weightman, Tuan Anh Bui, Oliver D’Arcy Robertso
Current trends and rationale for the use of outcome measures in routine clinical care
No full textAbstract no. 264B Pring, R McKay, M Weightman, G Galambos, and A Ki
Timing is everything event-related TDCS (er-TDCS) improves motor adaptation
No full textCoincident, time-dependent mechanisms of synaptic plasticity are the canonical basis of theories of motor learning. These ‘Hebbian’ mechanisms are ubiquitous throughout the mammalian brain, having been described in the hippocampus, cerebellum, and sensory-motor cortices, and are believed to underpin all forms of learning and memory. Yet, protocols for non-invasive brain stimulation intended to promote motor learning and rehabilitation - particularly transcranial direct current stimulation (TDCS) - largely ignore timing-dependent mechanisms. Changes in neuronal excitation have been shown to be almost instantaneous in terms of increases in firing rates and motor evoked potentials following the application of TDCS and other forms of polarising currents. Despite this, most conventional studies apply TDCS for 15-20 minutes in a continuous stimulation period, prior to and/or during a motor task. If TDCS can instantaneously modulate neural activity, applying short duration epochs of TDCS temporally aligned with movement has the potential to specifically and selectively enhance learning, by driving coincident mechanisms of plasticity in the circuits of the brain that are active during the movement.
Thus, we designed a context-dependent force-field adaptation task, in which we applied short epochs of TDCS coincidentally with one of two reaching movements performed during the task - a stimulation protocol we termed event-related TDCS (er-TDCS). Healthy young participants (n = 60) learned to reach through two opposing velocity-dependent force-fields, applied on interleaved trials in a pseudorandomised order. The two force-fields were contextually distinguished by a leftward or rightward shift in the visual display, although the movement was always performed in the midline. During adaptation a leftward shift in visual task display was associated with a clockwise (CW) curl-field and a rightward shift in display was associated with a counter-clockwise (CCW) curl-field. During baseline and washout, trials were still distinguished by workspace shifts but were performed without any forces applied (null-field). er-TDCS was selectively applied over the cerebellum or M1 in brief (< 3 second bouts) during movements through the CCW force-field, and associated rightward shift in visual task display. Consequently, only one of the two learning contexts was performed with simultaneous stimulation, while the unstimulated context provided a within-subject control.
We demonstrate that brief epochs of stimulation, applied in synchrony with movement, selectively enhanced motor adaptation whilst, importantly, leaving adaptation of the non-stimulated (yet interleaved) movements unaffected
Timing is everything event-related TDCS (er-TDCS) improves motor adaptation
No full textCoincident, time-dependent mechanisms of synaptic plasticity are the canonical basis of theories of motor learning. These ‘Hebbian’ mechanisms are ubiquitous throughout the mammalian brain, having been described in the hippocampus, cerebellum, and sensory-motor cortices, and are believed to underpin all forms of learning and memory. Yet, protocols for non-invasive brain stimulation intended to promote motor learning and rehabilitation - particularly transcranial direct current stimulation (TDCS) - largely ignore timing-dependent mechanisms. Changes in neuronal excitation have been shown to be almost instantaneous in terms of increases in firing rates and motor evoked potentials following the application of TDCS and other forms of polarising currents. Despite this, most conventional studies apply TDCS for 15-20 minutes in a continuous stimulation period, prior to and/or during a motor task. If TDCS can instantaneously modulate neural activity, applying short duration epochs of TDCS temporally aligned with movement has the potential to specifically and selectively enhance learning, by driving coincident mechanisms of plasticity in the circuits of the brain that are active during the movement.
Thus, we designed a context-dependent force-field adaptation task, in which we applied short epochs of TDCS coincidentally with one of two reaching movements performed during the task - a stimulation protocol we termed event-related TDCS (er-TDCS). Healthy young participants (n = 60) learned to reach through two opposing velocity-dependent force-fields, applied on interleaved trials in a pseudorandomised order. The two force-fields were contextually distinguished by a leftward or rightward shift in the visual display, although the movement was always performed in the midline. During adaptation a leftward shift in visual task display was associated with a clockwise (CW) curl-field and a rightward shift in display was associated with a counter-clockwise (CCW) curl-field. During baseline and washout, trials were still distinguished by workspace shifts but were performed without any forces applied (null-field). er-TDCS was selectively applied over the cerebellum or M1 in brief (< 3 second bouts) during movements through the CCW force-field, and associated rightward shift in visual task display. Consequently, only one of the two learning contexts was performed with simultaneous stimulation, while the unstimulated context provided a within-subject control.
We demonstrate that brief epochs of stimulation, applied in synchrony with movement, selectively enhanced motor adaptation whilst, importantly, leaving adaptation of the non-stimulated (yet interleaved) movements unaffected
A short geostatistical study of the three-dimensional spatial structure of fumonisins in stored maize
No full textThe heterogeneous three-dimensional spatial distribution of mycotoxins has
proven to be one of the main limitations for the design of effective sampling
protocols. Current sample collection protocols for mycotoxins have been designed
to estimate the mean concentration and fail to characterise the spatial
distribution of the mycotoxin concentration due to the aggregation of the
incremental samples. Geostatistical techniques have been successfully applied to
overcome similar problems in many research areas. However, little work has been
developed on the use of geostatistics for the design of sampling protocols for
mycotoxins. This paper focuses on the analysis of the two and three-dimensional
spatial structure of fumonisins B1 (FB1) and B2 (FB2) in maize in a bulk store
using a geostatistical approach and on how results help determine the number and
location of incremental samples to be collected. The spatial correlation between
FB1 and FB2, as well as between the number of kernels infected and the level of
contamination was investigated. For this purpose, a bed of maize was sampled at
different depths to generate a unique three-dimensional data set of FB1 and FB2.
The analysis found no clear evidence of spatial structure in either the two-
dimensional or three-dimensional analyses. The number of Fusarium infected
kernels was not a good indicator for the prediction of fumonisin concentration
and there was no spatial correlation between the concentrations of the two
fumonisins
End-of-2022 stocktake update
No full textCorrespondenceMichael Weightman, Tuan Anh Bui and Oliver D’Arcy Robertso
Myocardial grid-tagging is a superior predictor of myocardial viability than late gadolinium-enhanced magnetic resonance imaging post STEMI
No full textAbstract 520D. Wong, D. Leong, M. Weightman, M. Leung, J. Richardson, A. Bertaso, K. Teo, I. Meredith, M. Worthley, S. Worthle
Review Essay: Christine Weightman, \u3ci\u3eMargaret of York: Duchess of Burgundy, 1446-1503\u3c/i\u3e
No full textChristine Weightman, Margaret of York: Duchess of Burgundy, 1446-1503, St. Martin\u27s Press, 1989
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