Investigating interactions between search mechanisms in the control of visual attention

Olds, Cowan and Jolicoeur (2000) showed that although the mechanisms underlying visual search have traditionally been assumed to be independent. in fact they interact. Using coloured disk stimuli, they interrupted pop-out search (target plus Dl distractors) by adding more distractors (D2s) of a different colour to the display before pop-out processes were able to find the target. In short, partially completed pop-out processes facilitated subsequent difficult search processes (“search assistance ). The present study investigated hypotheses for this interaction. In Experiments 1 and 2, we used methods aimed at determining where the bulk of attentional resources are allocated during search of a visual display assumed to produce search assistance (by measuring the effect of inhibition of return [IOR] between DI and D2 locations). In Experiment 1, we first presented observers with a search task that has been shown to produce search assistance (using coloured disks: see Olds et al., 2000). Immediately following target response, observers had to determine as quickly and accurately as possible whether a small probe-dot (that appeared on one of the disks) was present or absent. The results of Experiment 1 provided tentative support for a negative prioritisation hypothesis which proposed that some initial distractors (Dls) are eliminated from consideration during the second portion of the display. The sequence of events in Experiment 2 were identical to that of Experiment 1 except that, following target response, observers had to make a temporal order judgement (TOJ) as to which of two physically simultaneous lines (one on a Dl, and one on a D2) appeared first. The results of Experiment 2 did not support either of the hypotheses regarding the nature of search assistance. Experiment 3 examined the effect of spatial cues on difficult search by attempting to eliminate the effect of negative prioritisation while measuring the effect of positive prioritisation. The results of Experiment 3 provided evidence in support of a positive prioritisation hypothesis which proposed that the initial items are more likely to be searched in the second portion of the display. Future research is discussed

Building audiences: Aboriginal and Torres Strait Islander arts

Building Audiences examines the barriers to and the strategies for increasing audiences in the Aboriginal and Torres Strait Islander arts sector. This research investigates the attitudes, beliefs and behaviours of current and potential audiences. What is in the report? The findings reveal the key barriers facing audience attendance include: uncertainty about how to behave at cultural events and fear of offending lack of awareness with audiences not actively seeking information about Indigenous arts and outdated perceptions of the sector – that it is only perceived as ‘serious or educational’. Building Audiences also considered several strategies to build audiences for Indigenous arts: providing skills development, advice and resourcing to Indigenous practitioners within the arts sector; increasing representation of Indigenous artists in the main programing of arts companies by including more Indigenous people in decision making roles; promoting relationships between Indigenous arts and non-Indigenous companies to present their work to wider audiences; introducing children and young people to Indigenous arts through schools and extracurricular activities; allowing audiences to feel comfortable engaging by creating accessible experiences; implementing long-term strategies to change negative perceptions of Indigenous arts. The project was commissioned by the Australia Council for the Arts and funding partners include Australia Council for the Arts; Faculty of Business and Law and Institute of Koorie Education, Deakin University; Melbourne Business School, The University of Melbourne

On-line evolutionary algorithm guidance for multiple missiles against multiple targets

This paper details the application of a Cooperative Coevolution On-Line Evolutionary Algorithm (CCOLEA) to the guidance of a swarm of multiple missiles, against multiple targets. The CCOLEA trades the spatial distribution of missiles at impact, against the cost of re-aiming the missiles' seekers onto their final targets. A parallel approach is used where each missile optimises its own performance, based on limited information from the other missiles. The decision making processis thus distributed between the missiles giving distributed coordination

Magnetic field-induced soft mode in spin-gapped high-Tc superconductors

We present an explanation of the dynamical in-gap spin mode in LSCO induced by an applied magnetic field H as recently observed by J. Chang et al. Our model consists of a phenomenological spin-only Hamiltonian, and the softening of the spin mode is caused by vortex pinning of dynamical stripe fluctuations which we model by a local ordering of the exchange interactions. The spin gap vanishes experimentally around H=7T which in our scenario corresponds to the field required for overlapping vortex regions.Comment: 4 pages, 3 fig

Humanism in the Age of COVID-19: Renewing Focus on Communication and Compassion

The global COVID-19 pandemic has become one of the largest clinical and operational challenges faced by emergency medicine, and our EDs continue to see increased volumes of infected patients, many of whom are not only ill, but acutely aware and fearful of their circumstances and potential mortality. Given this, there may be no more important time to focus on staff-patient communication and expression of compassion.However, many of the techniques usually employed by emergency clinicians to provide comfort to patients and their families are made more challenging or impossible by the current circumstances. Geriatric ED patients, who are at increased risk of severe disease, are particularly vulnerable to the effects of isolation.Despite many challenges, emergency clinicians have at their disposal a myriad of tools that can still be used to express compassion and empathy to their patients. Placing emphasis on using these techniques to maximize humanism in the care of COVID-19 patients during this crisis has the potential to bring improvements to ED patient care well after this pandemic has passed

A Shallowing-Upward Sequence in a Pleistocene Coral Reef and Associated Facies, San Salvador, Bahamas

The Sangamon-age Cockburn Town fossil coral reef complex displays a vertical sequence of facies from coral reef and closely associated subtidal carbonate sands, through beach calcarenites, to eolianites. This upward change reflects a progressive lowering of sea level and the eventual emergence of the reef complex into a subaerial environment. The contact between upper beach sediments and eolianites is at +4 m providing a minimum for the sea level high stand. Essentially in situ Acropora palmata suggests a sea level of at least 5 to 6 m above present. These values are similar to Sangamon-age high stands reported from New Providence, the northern Bahamas, and Bermuda. Northerly flowing longshore currents deposited trough cross-bedded carbonate sands around and over coral heads, and this implies the existence of ancient San Salvador during development of the coral reef complex. Land lying to the east of the reef also is indicated by westerly dipping beach bedding. A large-scale, westerly dipping, tabular cross-bedded set of calcarenite records the effects on the Cockburn Town fossil reef of a major storm or hurricane. The diagenetic sequence from submarine aragonite to freshwater vadose low-Mg calcite cements reflects the emergence of the reef complex and shows no evidence of subsequent immersion in marine waters. The sparsity of phreatic freshwater diagenetic effects may be due to a post-Sangamon rapid fall in sea level similar to that recorded for the same time on Bermuda, Calichification of all the facies of the reef complex and the development of rhizocretions resulted from extensive subaerial exposure and the growth of a vegetative cover respectively

The spatio-temporal tuning of the mechanisms in the control of saccadic eye movements

AbstractWe compared the spatio-temporal tuning of perception to the mechanisms that drive saccadic eye movements. Detection thresholds were measured for Gabor-targets presented left or right of fixation (4 or 8deg eccentricity), at one of four spatial frequencies (1, 2, 4 or 8cpd) oscillating at one of three temporal frequencies (1, 8 or 16Hz). We then measured saccade latency to each target presented at various multiples of detection threshold. Consistent with previous research, latency decreased as a function of contrast. However, at equal detection performance, we found no systematic difference in saccadic latency and no difference in average oculometric performance (% correct saccade direction) across the different target spatio-temporal frequencies. Furthermore, position error remained fairly constant across all conditions. The results are consistent with the idea that the spatio-temporal signals used for perception are the same as those used by the mechanisms driving saccadic eye movements

Expression profiling of snoRNAs in normal hematopoiesis and AML

Key Points A subset of snoRNAs is expressed in a developmental- and lineage-specific manner during human hematopoiesis. Neither host gene expression nor alternative splicing accounted for the observed differential expression of snoRNAs in a subset of AML.</jats:p

Analysis of microparticle penetration into human and porcine skin: non-invasive imaging with multiphoton excitation microscopy

At the University of Oxford and PowderJect Pharmaceuticals plc, a unique form of needle-free injection technology has been developed. Powdered vaccines and drugs in micro-particle form are accelerated in a high-speed gas flow to sufficient velocity to enter the skin, subsequently achieving a pharmaceutical effect. To optimize the delivery of vaccines and drugs with this method a detailed understanding of the interactive processes that occur between the microparticles and the skin is necessary. Investigations to date of micro-particle delivery into excised human and animal tissue have involved image analyses of histology sections. In the present study, a series of investigations were conducted on excised human and porcine skin using the technique of Multi-Photon fluorescence excitation Microscopy (MPM) to image particles and skin structures post-penetration. Micro-particles of various size and composition were imaged with infrared laser excitation. Three-dimensional images of stratum corneum and epidermal cell deformation due to micro-particle penetration were obtained. Measurements of micro-particle penetration depth taken from z-scan image stacks were used to successfully quantify micro-particle distribution within the skin, without invasively disrupting the skin target. This study has shown that MPM has great potential for the non-invasive imaging of particle skin interactive processes that occur with the transdermal delivery of powdered micro-particle vaccines and drugs