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Winnipeg, Canada

Ranjbar Pouya O.,University of Manitoba | Byagowi A.,University of Manitoba | Kelly D.M.,University of Manitoba | Moussavi Z.,University of Manitoba | Moussavi Z.,Research Affiliate
Quarterly Journal of Experimental Psychology | Year: 2016

Age-related impairments during spatial navigation have been widely reported in egocentric and allocentric paradigms. However, the effect of age on more specific navigational components such as the ability to drive or update directional information has not received enough attention. In this study we investigated the effect of age on spatial updating of a visual target after a series of whole-body rotations and transitions using a novel landmark-less virtual reality (VR) environment. Moreover, a significant number of previous studies focused on measures susceptible to a general decline in motor skills such as the spent time navigating, the distance traversed. The current paper proposes a new compound spatial measure to assess navigational performance, examines its reliability and compares its power with those of the measures of duration and traversed distance in predicting participants' age and cognitive groups assessed by Montreal Cognitive Assessment (MoCA) scores. Using data from 319 adults (20–83 years), our results confirm the reliability, the age sensitivity, and the cognitive validity of the designed spatial measure as well as its superiority to the measures of duration and traversed distance in predicting age and MoCA score. In addition, the results show the significant effect of age cognitive status on spatial updating. © 2016 The Experimental Psychology Society Source


McGrew J.S.,Massachusetts Institute of Technology | McGrew J.S.,Research Affiliate | How J.P.,Massachusetts Institute of Technology | Williams B.,Massachusetts Institute of Technology | And 3 more authors.
Journal of Guidance, Control, and Dynamics | Year: 2010

Unmanned aircraft systems have the potential to perform many of the dangerous missions currently flown by manned aircraft, yet the complexity of some tasks, such as air combat, have precluded unmanned aircraft systems from successfully carrying out these missions autonomously. This paper presents a formulation of a level-flight flxed- velocity one-on-one air-combat maneuvering problem and an approximate dynamic programming approach for computing an efficient approximation of the optimal policy. In the version of the problem formulation considered, the aircraft learning the optimal policy is given a slight performance advantage. This approximate dynamic programming approach provides a fast response to a rapidly changing tactical situation, long planning horizons, and good performance, without explicit coding of air-combat tactics. The method's success is due to extensive feature development, reward shaping, and trajectory sampling. An accompanying fast and effective rollout-based policy extraction method is used to accomplish online implementation. Simulation results are provided that demonstrate the robustness of the method against an opponent, beginning from both offensive and defensive situations. Flight results are also presented using unmanned aircraft systems flown at the Massachusetts Institute of Technology's real-time indoor autonomous vehicle test environment. Copyright © 2010 by James S. McGrew. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. Source


Harapan H.,University of Syiah Kuala | Fitra F.,University of Syiah Kuala | Fitra F.,Taipei Medical University | Ichsan I.,University of Syiah Kuala | And 7 more authors.
Tuberculosis | Year: 2013

The central proteins for protection against tuberculosis are attributed to interferon-γ, tumor necrosis factor-α, interleukin (IL)-6 and IL-1β, while IL-10 primarily suppresses anti-mycobacterial responses. Several studies found alteration of expression profile of genes involved in anti-mycobacterial responses in macrophages and natural killer (NK) cells from active and latent tuberculosis and from tuberculosis and healthy controls. This alteration of cellular composition might be regulated by microRNAs (miRNAs). Albeit only 1% of the genomic transcripts in mammalian cells encode miRNA, they are predicted to control the activity of more than 60% of all protein-coding genes and they have a huge influence in pathogenesis theory, diagnosis and treatment approach to some diseases. Several miRNAs have been found to regulate T cell differentiation and function and have critical role in regulating the innate function of macrophages, dendritic cells and NK cells. Here, we have reviewed the role of miRNAs implicated in tuberculosis infection, especially related to their new roles in the molecular pathology of tuberculosis immunology and as new targets for future tuberculosis diagnostics. © 2013 Elsevier Ltd. All rights reserved. Source


Van Bressem M.-F.,Cetacean Conservation Medicine Group CMED | Minton G.,University Malaysia Sarawak | Minton G.,British Petroleum | Sutaria D.,James Cook University | And 7 more authors.
Diseases of Aquatic Organisms | Year: 2014

The presence of cutaneous nodules is reported in vulnerable populations of Irra - waddy dolphins Orcaella brevirostris from Malaysia (Kuching, Bintulu-Similajau, Kinabatangan-Segama and Penang Island), India (Chilika Lagoon) and Bangladesh (Sundarbans). Approximately 5700 images taken for photo-identification studies in 2004 to 2013 were examined for skin disorders. Nodules were detected in 6 populations. They appeared as circumscribed elevations of the skin and varied in size from 2 to >30 mm, were sparse or numerous and occurred on all visible body areas. In 8 photo-identified (PI) dolphins from India and Malaysia, the lesions remained stable (N = 2) or progressed (N = 6) over months but did not regress. The 2 most severely affected individuals were seen in Kuching and the Chilika Lagoon. Their fate is unknown. Cutaneous nodules were sampled in a female that died in a gillnet in Kuching in 2012. Histologically, the lesions consisted of thick collagen bundles covered by a moderately hyperplasic epithelium and were diagnosed as fibropapillomas. Whether the nodules observed in the other O. brevirostris were also fibropapillomas remains to be investigated. Disease prevalence ranged from 2.2% (N = 46; Bintulu-Similajau) to 13.9% (N = 72; Chilika) in 4 populations from Malaysia and India. It was not significantly different in 3 study areas in eastern Malaysia. In Chilika, prevalence was significantly higher (p = 0.00078) in 2009 to 2011 (13.9%) than in 2004 to 2006 (2.8%) in 72 PI dolphins. The emergence of a novel disease in vulnerable O. brevirostris populations is of concern. © Inter-Research 2014. Source


Sarraf-Shirazi S.,University of Manitoba | Baril J.-F.,University of Manitoba | Moussavi Z.,University of Manitoba | Moussavi Z.,Research Affiliate
Medical and Biological Engineering and Computing | Year: 2012

The various malfunctions and difficulties of the swallowing mechanism necessitate various diagnostic techniques to address those problems. Swallowing sounds recorded from the trachea have been suggested as a noninvasive method of swallowing assessment. However, acquiring signals from the trachea can be difficult for those with loose skin. The objective of this pilot study was to explore the viability of using the ear and nose as alternative recording locations for recording swallowing sounds. We recorded the swallowing and breathing sounds of five healthy young individuals from the ear, nose and trachea, simultaneously. We computed time-frequency features and compared them for the different locations of recording. The features included the peak and the maximumfrequencies of thepower spectrum density, average power at different frequency bands and the wavelet coefficients. The average power calculated over the 4 octave bands between 150 and 2,400 Hz showed a consistent trend with less than 20 dB difference for the breath sounds of all the recording locations. Thus, analyzing breath sounds recorded from the ear and nose for the purpose of aspiration detection would give similar results to those from tracheal recordings; thus, ear and nose recording may be a viable alternative when tracheal recording is not possible. © International Federation for Medical and Biological Engineering 2012. Source

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