Publications by authors named "Patrick Dickinson"

8 Publications

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The Effect of Motion Direction and Eccentricity on Vection, VR Sickness and Head Movements in Virtual Reality.

Multisens Res 2021 Apr 20:1-40. Epub 2021 Apr 20.

Division of Psychology, Nottingham Trent University, 50 Shakespeare Street, Nottingham, NG1 4FQ, UK.

Virtual Reality (VR) experienced through head-mounted displays often leads to vection, discomfort and sway in the user. This study investigated the effect of motion direction and eccentricity on these three phenomena using optic flow patterns displayed using the Valve Index. Visual motion stimuli were presented in the centre, periphery or far periphery and moved either in depth (back and forth) or laterally (left and right). Overall vection was stronger for motion in depth compared to lateral motion. Additionally, eccentricity primarily affected stimuli moving in depth with stronger vection for more peripherally presented motion patterns compared to more central ones. Motion direction affected the various aspects of VR sickness differently and modulated the effect of eccentricity on VR sickness. For stimuli moving in depth far peripheral presentation caused more discomfort, whereas for lateral motion the central stimuli caused more discomfort. Stimuli moving in depth led to more head movements in the anterior-posterior direction when the entire visual field was stimulated. Observers demonstrated more head movements in the anterior-posterior direction compared to the medio-lateral direction throughout the entire experiment independent of motion direction or eccentricity of the presented moving stimulus. Head movements were elicited on the same plane as the moving stimulus only for stimuli moving in depth covering the entire visual field. A correlation showed a positive relationship between dizziness and vection duration and between general discomfort and sway. Identifying where in the visual field motion presented to an individual causes the least amount of VR sickness without losing vection and presence can guide development for Virtual Reality games, training and treatment programmes.
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http://dx.doi.org/10.1163/22134808-bja10049DOI Listing
April 2021

A bipartite transcription factor module controlling expression in the bundle sheath of Arabidopsis thaliana.

Nat Plants 2020 12 23;6(12):1468-1479. Epub 2020 Nov 23.

Department of Plant Sciences, University of Cambridge, Cambridge, UK.

C photosynthesis evolved repeatedly from the ancestral C state, improving photosynthetic efficiency by ~50%. In most C lineages, photosynthesis is compartmented between mesophyll and bundle sheath cells, but how gene expression is restricted to these cell types is poorly understood. Using the C model Arabidopsis thaliana, we identified cis-elements and transcription factors driving expression in bundle sheath strands. Upstream of the bundle sheath preferentially expressed MYB76 gene, we identified a region necessary and sufficient for expression containing two cis-elements associated with the MYC and MYB families of transcription factors. MYB76 expression is reduced in mutant alleles for these transcription factors. Moreover, downregulated genes shared by both mutants are preferentially expressed in the bundle sheath. Our findings are broadly relevant for understanding the spatial patterning of gene expression, provide specific insights into mechanisms associated with the evolution of C photosynthesis and identify a short tuneable sequence for manipulating gene expression in the bundle sheath.
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http://dx.doi.org/10.1038/s41477-020-00805-wDOI Listing
December 2020

An Interscholastic Network To Generate LexA Enhancer Trap Lines in Drosophila.

G3 (Bethesda) 2019 Jul;9(7):2097-2106

Phillips Exeter Academy, Exeter, NH 03833.

Binary expression systems like the LexA-LexAop system provide a powerful experimental tool kit to study gene and tissue function in developmental biology, neurobiology, and physiology. However, the number of well-defined LexA enhancer trap insertions remains limited. In this study, we present the molecular characterization and initial tissue expression analysis of nearly 100 novel StanEx LexA enhancer traps, derived from the StanEx1 index line. This includes 76 insertions into novel, distinct gene loci not previously associated with enhancer traps or targeted LexA constructs. Additionally, our studies revealed evidence for selective transposase-dependent replacement of a previously-undetected KP element on chromosome III within the StanEx1 genetic background during hybrid dysgenesis, suggesting a molecular basis for the over-representation of LexA insertions at the NK7.1 locus in our screen. Production and characterization of novel fly lines were performed by students and teachers in experiment-based genetics classes within a geographically diverse network of public and independent high schools. Thus, unique partnerships between secondary schools and university-based programs have produced and characterized novel genetic and molecular resources in Drosophila for open-source distribution, and provide paradigms for development of science education through experience-based pedagogy.
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http://dx.doi.org/10.1534/g3.119.400105DOI Listing
July 2019

An Interscholastic Network To Generate LexA Enhancer Trap Lines in .

G3 (Bethesda) 2019 07 9;9(7):2097-2106. Epub 2019 Jul 9.

Phillips Exeter Academy, Exeter, NH 03833.

Binary expression systems like the LexA-LexAop system provide a powerful experimental tool kit to study gene and tissue function in developmental biology, neurobiology, and physiology. However, the number of well-defined LexA enhancer trap insertions remains limited. In this study, we present the molecular characterization and initial tissue expression analysis of nearly 100 novel StanEx LexA enhancer traps, derived from the index line. This includes 76 insertions into novel, distinct gene loci not previously associated with enhancer traps or targeted LexA constructs. Additionally, our studies revealed evidence for selective transposase-dependent replacement of a previously-undetected element on chromosome III within the StanEx genetic background during hybrid dysgenesis, suggesting a molecular basis for the over-representation of LexA insertions at the locus in our screen. Production and characterization of novel fly lines were performed by students and teachers in experiment-based genetics classes within a geographically diverse network of public and independent high schools. Thus, unique partnerships between secondary schools and university-based programs have produced and characterized novel genetic and molecular resources in for open-source distribution, and provide paradigms for development of science education through experience-based pedagogy.
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http://dx.doi.org/10.1534/g3.119.400105DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6643891PMC
July 2019

Unpredictable movement as an anti-predator strategy.

Proc Biol Sci 2018 08 22;285(1885). Epub 2018 Aug 22.

School of Life Sciences, University of Lincoln, Lincoln LN6 7DL, UK

Prey animals have evolved a wide variety of behaviours to combat the threat of predation, and these have been generally well studied. However, one of the most common and taxonomically widespread antipredator behaviours of all has, remarkably, received almost no experimental attention: so-called 'protean' behaviour. This is behaviour that is sufficiently unpredictable to prevent a predator anticipating in detail the future position or actions of its prey. In this study, we used human 'predators' participating in 3D virtual reality simulations to test how protean (i.e. unpredictable) variation in prey movement affects participants' ability to visually target them as they move (a key determinant of successful predation). We found that targeting accuracy was significantly predicted by prey movement path complexity, although, surprisingly, there was little evidence that high levels of unpredictability in the underlying movement rules equated directly to decreased predator performance. Instead, the specific movement rules differed in how they impacted on targeting accuracy, with the efficacy of protean variation in one element depending on the values of the remaining elements. These findings provide important insights into the understudied phenomenon of protean antipredator behaviour, which are directly applicable to predator-prey dynamics within a broad range of taxa.
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http://dx.doi.org/10.1098/rspb.2018.1112DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6125907PMC
August 2018

Chloroplast Signaling Gates Thermotolerance in Arabidopsis.

Cell Rep 2018 02;22(7):1657-1665

Sainsbury Laboratory, University of Cambridge, Cambridge, UK. Electronic address:

Temperature is a key environmental variable influencing plant growth and survival. Protection against high temperature stress in eukaryotes is coordinated by heat shock factors (HSFs), transcription factors that activate the expression of protective chaperones such as HEAT SHOCK PROTEIN 70 (HSP70); however, the pathway by which temperature is sensed and integrated with other environmental signals into adaptive responses is not well understood. Plants are exposed to considerable diurnal variation in temperature, and we have found that there is diurnal variation in thermotolerance in Arabidopsis thaliana, with maximal thermotolerance coinciding with higher HSP70 expression during the day. In a forward genetic screen, we identified a key role for the chloroplast in controlling this response, suggesting that light-induced chloroplast signaling plays a key role. Consistent with this, we are able to globally activate binding of HSFA1a to its targets by altering redox status in planta independently of a heat shock.
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http://dx.doi.org/10.1016/j.celrep.2018.01.054DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5847188PMC
February 2018

Investigating Head Movements Induced by 'Riloid' Patterns in Migraine and Control Groups Using a Virtual Reality Display.

Multisens Res 2018 Jan 1;31(8):753-777. Epub 2018 Jan 1.

2School of Computer Science, University of Lincoln, Brayford Pool, Lincoln, LN6 7TS, UK.

Certain striped patterns can induce illusory motion, such as those used in op-art. The visual system and the vestibular system work together closely, and so it is possible that illusory motion from a visual stimulus can result in uncertainty in the vestibular system. This increased uncertainty may be measureable in terms of the magnitude of head movements. Head movements were measured using a head-mounted visual display. Results showed that stimuli associated with illusory motion also seem to induce greater head movements when compared to similar stimuli. Individuals with migraine are more susceptible to visual discomfort, and this includes illusory motion from striped stimuli. However, there was no evidence of increased effect of illusory motion on those with migraine compared to those without, suggesting that while motion illusions may affect discomfort judgements, this is not limited to only those with migraine.
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http://dx.doi.org/10.1163/22134808-20181310DOI Listing
January 2018

The G-Box Transcriptional Regulatory Code in Arabidopsis.

Plant Physiol 2017 Oct 1;175(2):628-640. Epub 2017 Sep 1.

Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, United Kingdom

Plants have significantly more transcription factor (TF) families than animals and fungi, and plant TF families tend to contain more genes; these expansions are linked to adaptation to environmental stressors. Many TF family members bind to similar or identical sequence motifs, such as G-boxes (CACGTG), so it is difficult to predict regulatory relationships. We determined that the flanking sequences near G-boxes help determine in vitro specificity but that this is insufficient to predict the transcription pattern of genes near G-boxes. Therefore, we constructed a gene regulatory network that identifies the set of bZIPs and bHLHs that are most predictive of the expression of genes downstream of perfect G-boxes. This network accurately predicts transcriptional patterns and reconstructs known regulatory subnetworks. Finally, we present Ara-BOX-cis (araboxcis.org), a Web site that provides interactive visualizations of the G-box regulatory network, a useful resource for generating predictions for gene regulatory relations.
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http://dx.doi.org/10.1104/pp.17.01086DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5619884PMC
October 2017