Research

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  • Ultrasound Backscatter Signal Characterization and Classification Using Autoregressive Modeling and Machine Learning Algorithms
    Ultrasound Backscatter Signal Characterization and Classification Using Autoregressive Modeling and Machine Learning Algorithms
    This research explores the possibility of monitoring apoptosis and classifying clusters of apoptotic cells based on the changes in ultrasound backscatter signals from the tissues. The backscatter from normal and apoptotic cells, using a high frequency ultrasound instrument are modeled through an Autoregressive (AR) modeling technique. The proper model order is calculated by tracking the error criteria in the reconstruction of the original signal. The AR model coefficients, which are assumed to contain the main statistical features of the signal, are passed as the input to Linear and Nonlinear machine classifiers (Fisher Linear Discriminant, Conditional Gaussian Classifier, Naive Bayes Classifier and Neural Networks with nonlinear activation functions). In addition, an adaptive signal segmentation method, (Least Squares Lattice Filter) is used to differentiate the data from layers of different cell types into stationary parts ready for modeling and classification., Online version of a conference paper originally published as: Ultrasound Backscatter Signal Characterization and Classification Using Autoregressive Modeling and Machine Learning Algorithms N.R. Farnoud, S. Krishnasn and M.C. Kolios In Proceedings of the 25th Annual International Conference of the IEEE EMBS (2003), pp. 2861-2864 Publisher URL: http://ieeexplore.ieee.org/xpls/abs_all.jsp?isnumber=28615&arnumber=1280515&count=256&index=223
    Ultrasound Microbubble Treatment Enhances Clathrin-Mediated Endocytosis and Fluid-Phase Uptake through Distinct Mechanisms
    Ultrasound Microbubble Treatment Enhances Clathrin-Mediated Endocytosis and Fluid-Phase Uptake through Distinct Mechanisms
    Drug delivery to tumors is limited by several factors, including drug permeability of the target cell plasma membrane. Ultrasound in combination with microbubbles (USMB) is a promising strategy to overcome these limitations. USMB treatment elicits enhanced cellular uptake of materials such as drugs, in part as a result of sheer stress and formation of transient membrane pores. Pores formed upon USMB treatment are rapidly resealed, suggesting that other processes such as enhanced endocytosis may contribute to the enhanced material uptake by cells upon USMB treatment. How USMB regulates endocytic processes remains incompletely understood. Cells constitutively utilize several distinct mechanisms of endocytosis, including clathrin-mediated endocytosis (CME) for the internalization of receptor-bound macromolecules such as Transferrin Receptor (TfR), and distinct mechanism(s) that mediate the majority of fluid-phase endocytosis. Tracking the abundance of TfR on the cell surface and the internalization of its ligand transferrin revealed that USMB acutely enhances the rate of CME. Total internal reflection fluorescence microscopy experiments revealed that USMB treatment altered the assembly of clathrin-coated pits, the basic structural units of CME. In addition, the rate of fluid-phase endocytosis was enhanced, but with delayed onset upon USMB treatment relative to the enhancement of CME, suggesting that the two processes are distinctly regulated by USMB. Indeed, vacuolin-1 or desipramine treatment prevented the enhancement of CME but not of fluid phase endocytosis upon USMB, suggesting that lysosome exocytosis and acid sphingomyelinase, respectively, are required for the regulation of CME but not fluid phase endocytosis upon USMB treatment. These results indicate that USMB enhances both CME and fluid phase endocytosis through distinct signaling mechanisms, and suggest that strategies for potentiating the enhancement of endocytosis upon USMB treatment may improve targeted drug delivery., Fekri F, Delos Santos RC, Karshafian R, Antonescu CN (2016) Ultrasound Microbubble Treatment Enhances Clathrin-Mediated Endocytosis and Fluid-Phase Uptake through Distinct Mechanisms. PLoS ONE 11(6): e0156754. doi:10.1371/journal.pone.0156754
    Understanding Internet Usage Among Broadband Households: A Study of Household Internet Use Survey Data
    Understanding Internet Usage Among Broadband Households: A Study of Household Internet Use Survey Data
    Statistics Canada, Science, Innovation and Electronic Information Division Working Papers, Catalogue no. 88F0006X, no. 3, ISSN 1706-8967, ISBN 978-0-662-48548-3, Statistics Canada, Science, Innovation and Electronic Information Division Working Papers, Catalogue no. 88F0006X, no. 3, ISSN 1706-8967, ISBN 978-0-662-48548-3
    Understanding the Design Concept Identification Process
    Understanding the Design Concept Identification Process
    In the design literature, the term design concept is often used de facto, or with only a brief definition provided. Despite the cursory definition for concept, the design process rests heavily on concepts, e.g., brainstorming and generating multiple design concepts, and subsequently identifying design concepts for concept selection, evaluation and development, etc. Concepts and concept formation are of particular interest in psychology, as concepts play a central role in human cognition. Concepts and concept identification are also of interest in other fields such as archaeology, bioinformatics and education. In this paper, we explore the process of design concept identification and address the issue of identifying design concepts in free-form text. Our exploratory experiment uses text transcripts of verbal concept generation sessions to first investigate agreeability between human concept identifiers. Next, we perform a language analysis on the transcripts to uncover language patterns that may differentiate between text segments containing concepts and text segments not containing concepts. Our results show that humans are adept at identifying and agreeing upon concepts (average agreeability > 0.70), and that there are significant language differences that may distinguish concept segments from non-concept segments (i.e., non-concept segments have significantly more verbs and borderline significantly more self-references than concept segments). In general, automated concept identification may lead to better integration of early conceptual design with more detailed and computable downstream processes, resulting in a unified design workflow.
    Undressing Fashion Metadata: Ryerson University Fashion Research Collection
    Undressing Fashion Metadata: Ryerson University Fashion Research Collection
    The purpose of this poster is to provide insight into the processes involved in making a unique fashion research and teaching collection discoverable in an online environment at Ryerson University. The online collection will provide a means for the users to identify what artifacts are available for research purposes and facilitate teaching in the classroom. The poster will highlight effective metadata standards and elements, cross-domain metadata uses, metadata mapping and implementation., Eichenlaub, N., Morgan, M., & Masak-Mida, I. (2014, October). Undressing Fashion Metadata: Ryerson University Fashion Research Collection. Proceedings of the International Conference on Dublin Core and Metadata Applications, 195-197. Retrieved from http://dcpapers.dublincore.org/pubs/article/view/3723/1946, Papers, Project Reports and Posters for DC-2014 in Austin, Texas, 8-11 October 2014
    Unmediated is the Message: Enhancements to Traditional Interlibrary Loan in a Canadian University
    Unmediated is the Message: Enhancements to Traditional Interlibrary Loan in a Canadian University
    This paper discusses the implementation and delivery, at Ryerson University Library in Canada, of three consortially-facilitated, user-centered initiatives to enhance traditional interlibrary loan services. Through a collaborative purchase of approximately 4,000 NetLibrary ebooks, with the Ontario Council of University Libraries (OCUL) consortium and the Consortium of Ontario Libraries, the Library provides unmediated access to shared monographs. Ryerson's fully-subsidized document delivery service allows users to order journal articles directly from the Canada Institute for Scientific and Technical Information (CISTI Source) database., Originally published in: Interlending & Document Supply, 32(3): 152-158. Publisher URL: http://www.emeraldinsight.com/10.1108/02641610410551978
    Urban resilience in Canada : research priorities and best practices for climate resilience in cities.
    Urban resilience in Canada : research priorities and best practices for climate resilience in cities.
    Brown, C., Shaker, R.R., Gorgolewski, M., Papp, V., & Alkins, S. (2016). Urban resilience in Canada: Research priorities and best practices for climate resilience in cities. [Technical report]. 1-39. Available from: http://digital.library.ryerson.ca/islandora/object/RULA%3A4286
    Urgency is a non-monotonic function of pulse rate
    Urgency is a non-monotonic function of pulse rate
    Magnitude estimation was used to assess the experience of ur- gency in pulse-train stimuli (pulsed white noise) ranging from 3.13 to 200 Hz. At low pulse rates, pulses were easily resolved. At high pulse rates, pulses fused together leading to a tonal sensation with a clear pitch level. Urgency ratings followed a nonmonotonic (polynomial) function with local maxima at 17.68 and 200 Hz. The same stimuli were also used in response time and pitch scaling experiments. Response times were negatively corre- lated with urgency ratings. Pitch scaling results indicated that urgency of pulse trains is mediated by the perceptual constructs of speed and pitch.
    User Task Scenarios for Map-Based Decision Support in Community Health Planning
    User Task Scenarios for Map-Based Decision Support in Community Health Planning
    Health outcomes are affected by the socio-demographic and physical-environmental characteristics of the places where people live. Therefore, epidemiologists have been interested in the use of maps to explore spatial patterns of disease for a long time. Geographic Information Systems (GIS) are not only useful when visualizing complex spatial datasets but also when mapping the results of analytical processes. One such process is multi-criteria evaluation (MCE), which can be used to generate composite measures of public health based on individual, medical and non-medical factors.The objective of this study was to determine if geovisual MCE can be an effective tool in community health planning. We provided highly interactive thematic maps coupled with MCE tools to planners at a community health centre and evaluated their use for community health planning and decision-making. User task scenarios were designed in a way to compare the usefulness of different representation methods for a number of tasks.The pilot user test with two expert participants included interviews, questionnaires, and user task scenarios with think-aloud audio and screen video recording. We assessed the easiness of completing the tasks using completion rates and times and could identify a number of specific usability issues with the tool at hand.
    Uses and gratifications factors for social media use in teaching: Instructors’ perspectives
    Uses and gratifications factors for social media use in teaching: Instructors’ perspectives
    This research was motivated by an interest in understanding how social media are applied in teaching in higher education. Data were collected using an online questionnaire, completed by 333 instructors in higher education, that asked about general social media use and specific use in teaching. Education and learning theories suggest three potential reasons for instructors to use social media in their teaching: (1) exposing students to practices, (2) extending the range of the learning environment, and (3) promoting learning through social interaction and collaboration. Answers to open-ended questions about how social media were used in teaching, and results of a factor analysis of coded results, revealed six distinct factors that align with these reasons for use: (1) facilitating student engagement, (2) instructor’s organization for teaching, (3) engagement with outside resources, (4) enhancing student attention to content, (5) building communities of practice, and (6) resource discovery. These factors accord with a Uses and Gratifications perspective that depicts adopters as active media users choosing and shaping media use to meet their own needs. Results provide a more comprehensive picture of social media use than found in previous work, encompassing not only the array of media used but also the range of purposes associated with use of social media in contemporary teaching initiatives. Keywords: Adoption of technology, educational technology, higher education, instructor experiences, social media, teaching, Uses and Gratifications, Gruzd, A., Haythornthwaite, C., Paulin, D., Gilbert, S., & Esteve del Valle, M. (2016). Uses and gratifications factors for social media use in teaching: Instructors’ perspectives. New Media and Society. http://nms.sagepub.com/content/early/2016/08/08/1461444816662933.abstrac
    Using GIS towards the Characterization and Soil Mapping of the Caia Irrigation Perimeter
    Using GIS towards the Characterization and Soil Mapping of the Caia Irrigation Perimeter
    The Caia Irrigation Perimeter is an irrigation infrastructure implemented in 1968. As is often the case, the original soil map of this region (dated from 1961) does not have the detail needed to characterize a relatively small-sized zone, where intensive agricultural practices take place. Using FAO methodology and with the main goal of establishing a larger-scale soil map, adequate for the demands of a modern and intensive agriculture, we gathered the geological characterization of the study area and information about the topography, climate, and vegetation of the region. Using ArcGIS software, we overlapped this information and established a pre-map of soil resources. Based on this pre-map, we defined a set of detailed itineraries in the field, evenly distributed, in which soil samples were collected. In those distinct soil units, we opened several soil profiles, from which we selected 26 to analyze in the present study, since they characterized the existing diversity in terms of soil type and soil properties. Based on the work of verification, correction, and reinterpretation of the preliminary soil map, we reached a final soil map for the Caia Irrigation Perimeter, which is characterized by enormous heterogeneity, typical of Mediterranean soils, containing 23 distinct cartographic units, the most representative being the Distric Fluvisols with inclusions of Luvisols Distric occupying 29.9% of the total study area, and Calcisols Luvic with inclusions of Luvisols endoleptic with 11.9% of the total area. Considering the obtained information on soil properties; ArcGIS was used to develop a map in which it was possible to ascertain the impact of the continuous practice of irrigation in this area. This allows us to put forward relevant conclusions on the need to access and monitor specific Mediterranean soils in order to mitigate the environmental impact of irrigation practices., Nunes, J., Loures, L., Lopez-Piñeiro, A., Loures, A., & Vaz, E. (2016). Using GIS towards the characterization and soil mapping of the caia irrigation perimeter. Sustainability, 8(4), 368. doi:10.3390/su8040368, (This article belongs to the Special Issue Earth Observation and Geoinformation Technologies for Sustainable Development)