15,180 research outputs found

    Connectionist Temporal Modeling for Weakly Supervised Action Labeling

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    We propose a weakly-supervised framework for action labeling in video, where only the order of occurring actions is required during training time. The key challenge is that the per-frame alignments between the input (video) and label (action) sequences are unknown during training. We address this by introducing the Extended Connectionist Temporal Classification (ECTC) framework to efficiently evaluate all possible alignments via dynamic programming and explicitly enforce their consistency with frame-to-frame visual similarities. This protects the model from distractions of visually inconsistent or degenerated alignments without the need of temporal supervision. We further extend our framework to the semi-supervised case when a few frames are sparsely annotated in a video. With less than 1% of labeled frames per video, our method is able to outperform existing semi-supervised approaches and achieve comparable performance to that of fully supervised approaches.Comment: To appear in ECCV 201

    The relevance of diatoms for water quality assessment in South Africa: A position paper

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    Water quality assessment protocols based on the use of diatoms are now well developed and their value substantiated at an international level. The use of diatoms is not designed or intended to be a “rapid” technology. The detailed level of information generated from the procedure outweighs perceived disadvantages of the additional time required for sample preparation and analysis to species level. The method is applicable across a wide range of aquatic ecosystem types, namely freshwater, brackish, and estuarine, and is inclusive of both lentic and lotic environments, wetlands and their associated damp, marginal and littoral zones. Details provided by diatom assemblages support palaeoecological investigations, historical reconstruction of water quality and the determination of prevailing water quality conditions. Deliberate determination of responses to management strategies or impacts arising from a variety of anthropogenic activities can be achieved via the simple expedient of retrieving living material from introduced artificial substrates. Previous studies in South Africa and elsewhere have shown that on a site-by-site basis the use of diatoms provides a fine level of diagnostic resolution of the causes underlying changes in water quality and environmental condition. The South African Diatom Collection (“the Collection”), a repository of diatom specimens and records that spans the length and breadth of this country, contains an as-yet unutilised wealth of ecological and taxonomic information. More importantly, the historical data analysis records provide an insight into water quality conditions prevailing 40 to 50 years ago – in many cases prior to the “development” of many of our rivers, streams and wetlands. The real value of its existence underpins the great potential for renewed attention to the value of diatom-based approaches to water quality assessments. In addition, the Collection provides a ready-made foundation on which a locally relevant tool for water quality assessment may be established to augment the current use of invertebrate indicators. It is now appropriate that the full potential of the use of diatoms in water quality assessments, and the information contained in the Collection, be developed and utilised for water quality assessment in South Africa. Key words: diatoms, water quality, Cholnoky, Archibald, biotic indices Water SA Vol.31(1) 2005: 41-4

    Implementing the REPAIRER Human Factors Safety Reporting System Through MRM (MxHF) to Meet SMS Compliance in Aviation Maintenance

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    Reiterating the importance of having a human factor related safety reporting system for aviation maintenance to reduce human error and utilizing it to gain SMS compliance, the REPAIRER method of identifying and reporting human factors hazards in aviation maintenance is reintroduced. How and why the REPAIRER method system is of such importance in the implementation of aviation maintenance safety programs can be linked to the success and evolution of maintenance resource management and human factors programs which have been effective in reducing human error in aviation maintenance. These programs are rooted in effective communication methods, as well as the identification of human factor elements. To illustrate this point, the successes of maintenance resource management are discussed. Additionally, the incredible strides that the Federal Aviation Administration (FAA) has taken to propel a human factorscentered safety program in aviation maintenance are brought to light with the FAA’s latest transition of MRM (Maintenance Resource Management) to MxHF (Maintenance Human Factors). This newly appointed program, which replaced a decades old FAA MRM program, highlights the significant changes in MRM, notably the emphasis on human factors. Given the significant shift from MRM to MxHF, the authors explore the implementation of the REPAIRER aviation maintenance reporting system under the new guidelines and demonstrate how it could fulfill many of the desired outcomes of both programs, while still gaining SMS compliance

    Adiposity is associated with blunted cardiovascular, neuroendocrine and cognitive responses to acute mental stress

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    This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited - Copyright @ 2012 Jones et al.Obesity and mental stress are potent risk factors for cardiovascular disease but their relationship with each other is unclear. Resilience to stress may differ according to adiposity. Early studies that addressed this are difficult to interpret due to conflicting findings and limited methods. Recent advances in assessment of cardiovascular stress responses and of fat distribution allow accurate assessment of associations between adiposity and stress responsiveness. We measured responses to the Montreal Imaging Stress Task in healthy men (N=43) and women (N=45) with a wide range of BMIs. Heart rate (HR) and blood pressure (BP) measures were used with novel magnetic resonance measures of stroke volume (SV), cardiac output (CO), total peripheral resistance (TPR) and arterial compliance to assess cardiovascular responses. Salivary cortisol and the number and speed of answers to mathematics problems in the task were used to assess neuroendocrine and cognitive responses, respectively. Visceral and subcutaneous fat was measured using T2*-IDEAL. Greater BMI was associated with generalised blunting of cardiovascular (HR:β=−0.50 bpm.unit−1, P=0.009; SV:β=−0.33 mL.unit−1, P=0.01; CO:β=−61 mL.min−1.unit−1, P=0.002; systolic BP:β=−0.41 mmHg.unit−1, P=0.01; TPR:β=0.11 WU.unit−1, P=0.02), cognitive (correct answers: r=−0.28, P=0.01; time to answer: r=0.26, P=0.02) and endocrine responses (cortisol: r=−0.25, P=0.04) to stress. These associations were largely determined by visceral adiposity except for those related to cognitive performance, which were determined by both visceral and subcutaneous adiposity. Our findings suggest that adiposity is associated with centrally reduced stress responsiveness. Although this may mitigate some long-term health risks of stress responsiveness, reduced performance under stress may be a more immediate negative consequence.This work is funded by the UK National Institute of Health Research (NIHR), Siemens Medical Systems, British Heart Foundation (BHF), NIHR Senior Research Fellowship & The Fondation Leducq, BHF Intermediate Fellowship

    PB.42: Arbitration of round masses: understanding the variability of recall rates

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    Diatoms as indicators of water quality in the Jukskei-Crocodile river system in 1956 and 1957, a re-analysis of diatom count data generated by BJ Cholnoky

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    South Africa has a long legacy of diatom research. The eminent diatomist Dr BJ Cholnoky spent much of his working life examining and enumerating diatom communities found in Southern Africa. Most if not all of Cholnoky's collected diatom material in the form of mounted material on glass slides accompanied by diatom analysis sheets is stored in the South African Diatom Collection currently housed at the CSIR in Durban. As Cholnoky only employed enumeration methods yielding a margin of error of 2% or less, Cholnoky's results should provide an accurate reflection of the structure of the diatom communities that he examined. It is the aim of the present study to demonstrate the value of these historical diatom analyses for inferring past water quality conditions using the diatom-based index method. Data for the Jukskei-Crocodile River system were obtained from the South African Diatom Collection for the period 1956/1957. The nomenclature of the diatoms listed on Cholnoky's data sheets was modernised and the data then entered into OMNIDIA v3.1. Diatom index scores generated from OMNIDIA v3.1 were in general in agreement with Cholnoky's own assessment of water quality (especially with reference to organic pollution). It is concluded that the diatom analysis records housed in the South African Diatom Collection constitute a valuable resource for the assessment of past conditions of rivers and streams.. Water SA Vol. 31 (2) 2005: pp.237-24

    Intravenous Midazolam-Droperidol (combination), Droperidol (only) or Olanzapine (only) for the acutely agitated patient: A multi-centred, randomised, double-blind, triple-dummy, clinical trial

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    AIM: To determine the most efficacious of three currently used drug regimens for the sedation of acutely agitated patients in the emergency department ...postprin

    Midazolam-droperidol, droperidol or olanzapine for acute agitation: a randomised clinical trial

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    STUDY OBJECTIVE: We aim to determine the most efficacious of 3 common medication regimens for the sedation of acutely agitated emergency department (ED) patients. METHODS: We undertook a randomized, controlled, double-blind, triple-dummy, clinical trial in 2 metropolitan EDs between October 2014 and August 2015. Patients aged 18 to 65 years and requiring intravenous medication sedation for acute agitation were enrolled and randomized to an intravenous bolus of midazolam 5 mg-droperidol 5 mg, droperidol 10 mg, or olanzapine 10 mg. Two additional doses were administered, if required: midazolam 5 mg, droperidol 5 mg, or olanzapine 5 mg. The primary outcome was the proportion of patients adequately sedated at 10 minutes. RESULTS: Three hundred forty-nine patients were randomized to the 3 groups. Baseline characteristics were similar across the groups. Ten minutes after the first dose, significantly more patients in the midazolam-droperidol group were adequately sedated compared with the droperidol and olanzapine groups: differences in proportions 25.0% (95% confidence interval [CI] 12.0% to 38.1%) and 25.4% (95% CI 12.7% to 38.3%), respectively. For times to sedation, the differences in medians between the midazolam-droperidol group and the droperidol and olanzapine groups were 6 (95% CI 3 to 8) and 6 (95% CI 3 to 7) minutes, respectively. Patients in the midazolam-droperidol group required fewer additional doses or alternative drugs to achieve adequate sedation. The 3 groups' adverse event rates and lengths of stay did not differ. CONCLUSION: Midazolam-droperidol combination therapy is superior, in the doses studied, to either droperidol or olanzapine monotherapy for intravenous sedation of the acutely agitated ED patient. Copyright © 2016 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.postprin

    May I have your consent? Informed consent in clinical trials- feasibility in emergency situations

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    Clinical researchers in acute emergency settings are commonly faced with the difficulty of satisfying the conventional ethical requirement of obtaining informed consent, whilst ensuring a representative group of patients is recruited into studies. We discuss our own experience in addressing institutional ethical requirements to obtain informed consent in a multi-centre trial, recruiting highly agitated patients in the emergency setting in Melbourne, Australia. We suggest that, through the application of existing ethical and legal frameworks and pre-emptive communication with the key stakeholders in ethics committees, hospital insurers and legal representatives, a balance can be struck between ethical and legal requirements on the one hand, and the integrity of the research question, on the other.published_or_final_versio
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