False memory guided eye movements::insights from a DRM-Saccade paradigm

The Deese-Roediger and McDermott (DRM) paradigm and visually guided saccade tasks are both prominent research tools in their own right. This study introduces a novel DRM-Saccade paradigm, merging both methodologies. We used rule-based saccadic eye movements whereby participants were presented with items at test and were asked to make a saccade to the left or right of the item to denote a recognition or non-recognition decision. We measured old/new recognition decisions and saccadic latencies. Experiment 1 used a pro/anti saccade task to a single target. We found slower saccadic latencies for correct rejection of critical lures, but no latency difference between correct recognition of studied items and false recognition of critical lures. Experiment 2 used a two-target saccade task and also measured corrective saccades. Findings corroborated those from Experiment 1. Participants adjusted their initial decisions to increase accurate recognition of studied items and rejection of unrelated lures but there were no such corrections for critical lures. We argue that rapid saccades indicate cognitive processing driven by familiarity thresholds. These occur before slower source-monitoring is able to process any conflict. The DRM-saccade task could effectively track real-time cognitive resource use during recognition decisions

False memory-guided eye movements: insights from a DRM-Saccade paradigm

The Deese-Roediger and McDermott (DRM) paradigm and visually guided saccade tasks are both prominent research tools in their own right. This study introduces a novel DRM-Saccade paradigm, merging both methodologies. We used rule-based saccadic eye movements whereby participants were presented with items at test and were asked to make a saccade to the left or right of the item to denote a recognition or non-recognition decision. We measured old/new recognition decisions and saccadic latencies. Experiment 1 used a pro/anti saccade task to a single target. We found slower saccadic latencies for correct rejection of critical lures, but no latency difference between correct recognition of studied items and false recognition of critical lures. Experiment 2 used a two-target saccade task and also measured corrective saccades. Findings corroborated those from Experiment 1. Participants adjusted their initial decisions to increase accurate recognition of studied items and rejection of unrelated lures but there were no such corrections for critical lures. We argue that rapid saccades indicate cognitive processing driven by familiarity thresholds. These occur before slower source-monitoring is able to process any conflict. The DRM-Saccade task could effectively track real-time cognitive resource use during recognition decisions

Diversity of cortico-descending projections: histological and diffusion MRI characterization in the monkey

The axonal composition of cortical projections originating in premotor, supplementary motor (SMA), primary motor (a4), somatosensory and parietal areas and descending towards the brain stem and spinal cord was characterized in the monkey with histological tract tracing, electron microscopy (EM) and diffusion MRI (dMRI). These 3 approaches provided complementary information. Histology provided accurate assessment of axonal diameters and size of synaptic boutons. dMRI revealed the topography of the projections (tractography), notably in the internal capsule. From measurements of axon diameters axonal conduction velocities were computed. Each area communicates with different diameter axons and this generates a hierarchy of conduction delays in this order: a4 (the shortest), SMA, premotor (F7), parietal, somatosensory, premotor F4 (the longest). We provide new interpretations for i) the well-known different anatomical and electrophysiological estimates of conduction velocity; ii) why conduction delays are probably an essential component of the cortical motor command; and iii) how histological and dMRI tractography can be integrated

Clinical presentation, biochemical, and haematological parameters and their association with outcome in patients with Ebola virus disease: an observational cohort study.

BACKGROUND: Clinical management of Ebola virus disease remains challenging. Routine laboratory analytics are often unavailable in the outbreak setting, and few data exist for the associated haematological and biochemical abnormalities. We aimed to assess laboratory and clinical data from patients with Ebola virus disease to better inform clinical management algorithms, improve understanding of key variables associated with outcome, and provide insight into the pathophysiology of Ebola virus disease. METHODS: We recruited all patients, alive on arrival, with confirmed Ebola virus disease who were admitted to the Kerry Town Ebola treatment centre in Sierra Leone. At admission, all patients had clinical presentation recorded and blood taken for Ebola confirmation using reverse-transcriptase-PCR (RT-PCR) and for haematological and biochemical analysis. We studied the association between these and clinical outcome. The primary outcome was discharge from the Ebola treatment centre. FINDINGS: 150 patients were admitted to the treatment centre between Dec 8, 2014, and Jan 9, 2015. The mean age of patients was 26 years (SD 14·7). Case fatality rate was 37% (55/150). Most patients presented with stage 2 (gastrointestinal involvement, 72/118 [61%]) and stage 3 (severe or complicated, 12/118 [10%]) disease. Acute kidney injury was common (52/104 [50%]), as were abnormal serum potassium (32/97 [33%]), severe hepatitis (54/92 [59%]), and raised C-reactive protein (21/100 [21%]). Haematological abnormalities were common, including raised haematocrit (15/100 [15%]), thrombocytopenia (47/104 [45%]), and granulocytosis (44/104 [42%]). Severe acute kidney injury, low RT-PCR cycle threshold (<20 cycles), and severe hepatitis were independently associated with mortality. INTERPRETATION: Ebola virus disease is associated with a high prevalence of haematological and biochemical abnormalities, even in mild disease and in the absence of gastrointestinal symptoms. Clinical care that targets hypovolaemia, electrolyte disturbance, and acute kidney injury is likely to reduce historically high case fatality rates. FUNDING: None

Improving the design process for factories:modelling human performance variation

Theprocess of manufacturing system design frequently includes modeling, and usually, this means applying a technique such as discrete event simulation (DES). However, the computer tools currently available to apply this technique enable only a superficial representation of the people that operate within the systems. This is a serious limitation because the performance of people remains central to the competitiveness of many manufacturing enterprises. Therefore, this paper explores the use of probability density functions to represent the variation of worker activity times within DES models

Effects of human footprint and biophysical factors on the body-size structure of fished marine species

Marine fisheries in coastal ecosystems in many areas of the world have historically removed large-bodied individuals, potentially impairing ecosystem functioning and the long-term sustainability of fish populations. Reporting on size-based indicators that link to food-web structure can contribute to ecosystem-based management, but the application of these indicators over large (cross-ecosystem) geographical scales has been limited to either fisheries-dependent catch data or diver-based methods restricted to shallow waters (<20 m) that can misrepresent the abundance of large-bodied fished species. We obtained data on the body-size structure of 82 recreationally or commercially targeted marine demersal teleosts from 2904 deployments of baited remote underwater stereo-video (stereo-BRUV). Sampling was at up to 50 m depth and covered approximately 10,000 km of the continental shelf of Australia. Seascape relief, water depth, and human gravity (i.e., a proxy of human impacts) were the strongest predictors of the probability of occurrence of large fishes and the abundance of fishes above the minimum legal size of capture. No-take marine reserves had a positive effect on the abundance of fishes above legal size, although the effect varied across species groups. In contrast, sublegal fishes were best predicted by gradients in sea surface temperature (mean and variance). In areas of low human impact, large fishes were about three times more likely to be encountered and fishes of legal size were approximately five times more abundant. For conspicuous species groups with contrasting habitat, environmental, and biogeographic affinities, abundance of legal-size fishes typically declined as human impact increased. Our large-scale quantitative analyses highlight the combined importance of seascape complexity, regions with low human footprint, and no-take marine reserves in protecting large-bodied fishes across a broad range of species and ecosystem configurations.publishedVersio

A field and video-annotation guide for baited remote underwater stereo-video surveys of demersal fish assemblages

Researchers TL, BG, JW, NB and JM were supported by the Marine Biodiversity Hub through funding from the Australian Government's National Environmental Science Program. Data validation scripts and GlobalArchive.org were supported by the Australian Research Data Commons, the Gorgon-Barrow Island Gorgon Barrow Island Net Conservation Benefits Fund, administered by the Government of Western Australia and the BHP/UWA Biodiversity and Societal Benefits of Restricted Access Areas collaboration.1. Baited remote underwater stereo-video systems (stereo-BRUVs) are a popular tool to sample demersal fish assemblages and gather data on their relative abundance and body-size structure in a robust, cost-effective, and non-invasive manner. Given the rapid uptake of the method, subtle differences have emerged in the way stereo-BRUVs are deployed and how the resulting imagery are annotated. These disparities limit the interoperability of datasets obtained across studies, preventing broad-scale insights into the dynamics of ecological systems. 2. We provide the first globally accepted guide for using stereo-BRUVs to survey demersal fish assemblages and associated benthic habitats. 3. Information on stereo-BRUV design, camera settings, field operations, and image annotation are outlined. Additionally, we provide links to protocols for data validation, archiving, and sharing. 4. Globally, the use of stereo-BRUVs is spreading rapidly. We provide a standardised protocol that will reduce methodological variation among researchers and encourage the use of Findable, Accessible, Interoperable, and Reproducible (FAIR) workflows to increase the ability to synthesise global datasets and answer a broad suite of ecological questions.Publisher PDFPeer reviewe

Comparing the Invasibility of Experimental “Reefs” with Field Observations of Natural Reefs and Artificial Structures

Natural systems are increasingly being modified by the addition of artificial habitats which may facilitate invasion. Where invaders are able to disperse from artificial habitats, their impact may spread to surrounding natural communities and therefore it is important to investigate potential factors that reduce or enhance invasibility. We surveyed the distribution of non-indigenous and native invertebrates and algae between artificial habitats and natural reefs in a marine subtidal system. We also deployed sandstone plates as experimental ‘reefs’ and manipulated the orientation, starting assemblage and degree of shading. Invertebrates (non-indigenous and native) appeared to be responding to similar environmental factors (e.g. orientation) and occupied most space on artificial structures and to a lesser extent reef walls. Non-indigenous invertebrates are less successful than native invertebrates on horizontal reefs despite functional similarities. Manipulative experiments revealed that even when non-indigenous invertebrates invade vertical “reefs”, they are unlikely to gain a foothold and never exceed covers of native invertebrates (regardless of space availability). Community ecology suggests that invertebrates will dominate reef walls and algae horizontal reefs due to functional differences, however our surveys revealed that native algae dominate both vertical and horizontal reefs in shallow estuarine systems. Few non-indigenous algae were sampled in the study, however where invasive algal species are present in a system, they may present a threat to reef communities. Our findings suggest that non-indigenous species are less successful at occupying space on reef compared to artificial structures, and manipulations of biotic and abiotic conditions (primarily orientation and to a lesser extent biotic resistance) on experimental “reefs” explained a large portion of this variation, however they could not fully explain the magnitude of differences

The Australasian Resuscitation In Sepsis Evaluation : fluids or vasopressors in emergency department sepsis (ARISE FLUIDS), a multi-centre observational study describing current practice in Australia and New Zealand

Objectives: To describe haemodynamic resuscitation practices in ED patients with suspected sepsis and hypotension. Methods: This was a prospective, multicentre, observational study conducted in 70 hospitals in Australia and New Zealand between September 2018 and January 2019. Consecutive adults presenting to the ED during a 30-day period at each site, with suspected sepsis and hypotension (systolic blood pressure <100 mmHg) despite at least 1000 mL fluid resuscitation, were eligible. Data included baseline demographics, clinical and laboratory variables and intravenous fluid volume administered, vasopressor administration at baseline and 6- and 24-h post-enrolment, time to antimicrobial administration, intensive care admission, organ support and in-hospital mortality. Results: A total of 4477 patients were screened and 591 were included with a mean (standard deviation) age of 62 (19) years, Acute Physiology and Chronic Health Evaluation II score 15.2 (6.6) and a median (interquartile range) systolic blood pressure of 94 mmHg (87–100). Median time to first intravenous antimicrobials was 77 min (42–148). A vasopressor infusion was commenced within 24 h in 177 (30.2%) patients, with noradrenaline the most frequently used (n = 138, 78%). A median of 2000 mL (1500–3000) of intravenous fluids was administered prior to commencing vasopressors. The total volume of fluid administered from pre-enrolment to 24 h was 4200 mL (3000–5661), with a range from 1000 to 12 200 mL. Two hundred and eighteen patients (37.1%) were admitted to an intensive care unit. Overall in-hospital mortality was 6.2% (95% confidence interval 4.4–8.5%). Conclusion: Current resuscitation practice in patients with sepsis and hypotension varies widely and occupies the spectrum between a restricted volume/earlier vasopressor and liberal fluid/later vasopressor strategy

Progressive skin fibrosis is associated with a decline in lung function and worse survival in patients with diffuse cutaneous systemic sclerosis in the European Scleroderma Trials and Research (EUSTAR) cohort.

Objectives To determine whether progressive skin fibrosis is associated with visceral organ progression and mortality during follow-up in patients with diffuse cutaneous systemic sclerosis (dcSSc). Methods We evaluated patients from the European Scleroderma Trials and Research database with dcSSc, baseline modified Rodnan skin score (mRSS) ≥7, valid mRSS at 12±3 months after baseline and ≥1 annual follow-up visit. Progressive skin fibrosis was defined as an increase in mRSS &gt;5 and ≥25% from baseline to 12±3 months. Outcomes were pulmonary, cardiovascular and renal progression, and all-cause death. Associations between skin progression and outcomes were evaluated by Kaplan-Meier survival analysis and multivariable Cox regression. Results Of 1021 included patients, 78 (7.6%) had progressive skin fibrosis (skin progressors). Median follow-up was 3.4 years. Survival analyses indicated that skin progressors had a significantly higher probability of FVC decline ≥10% (53.6% vs 34.4%; p&lt;0.001) and all-cause death (15.4% vs 7.3%; p=0.003) than non-progressors. These significant associations were also found in subgroup analyses of patients with either low baseline mRSS (≤22/51) or short disease duration (≤15 months). In multivariable analyses, skin progression within 1 year was independently associated with FVC decline ≥10% (HR 1.79, 95% CI 1.20 to 2.65) and all-cause death (HR 2.58, 95% CI 1.31 to 5.09). Conclusions Progressive skin fibrosis within 1 year is associated with decline in lung function and worse survival in dcSSc during follow-up. These results confirm mRSS as a surrogate marker in dcSSc, which will be helpful for cohort enrichment in future trials and risk stratification in clinical practice