27 results on '"Dey A."'
Search Results
2. Potent and long-lasting humoral and cellular immunity against varicella zoster virus induced by mRNA-LNP vaccine.
- Author
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Bhattacharya, Anannya, Jan, Lonzaric, Burlak, Olga, Li, Jilong, Upadhyay, Ghanshyam, Williams, Katherine, Dong, Jinhui, Rohrer, Harrison, Pynn, Michelle, Simon, Andrew, Kuhlmann, Nathan, Pustylnikov, Sergei, Melo, Mariane B., and Dey, Antu K.
- Subjects
CELLULAR immunity ,VARICELLA-zoster virus ,HERPES zoster vaccines ,HERPES zoster ,VACCINATION - Abstract
Varicella zoster virus (VZV) is a highly contagious human herpes virus responsible for causing chickenpox (varicella) and shingles (herpes zoster). Despite the approval of a highly effective vaccine, Shingrix
® , the global incidence of herpes zoster is increasing and the economic burden to the health care system and society are substantial due to significant loss of productivity and health complications, particularly among elderly and immunocompromised individuals. This is primarily because access to the vaccines remains mostly limited to countries within developed economies, such as USA and Canada. Therefore, similarly effective vaccines against VZV that are more accessible to the rest-of-the-world are necessary. In this study, we aimed to evaluate immunogenicity and memory response induced by three mRNA-LNP-based vaccine candidates targeting VZV's surface glycoprotein E (gE). C57BL/6 mice were immunized with each candidate vaccine, and humoral and cellular immune responses were assessed. Our results demonstrate that the mRNA-LNP-based vaccine candidates elicited robust and durable humoral responses specific to the gE antigen. Notably, mice vaccinated with the mRNA-LNP vaccines exhibited significantly higher antigen-specific T-cell cytokine production compared to the group receiving Shingrix® , the current standard of care vaccine. Additionally, mRNA-LNP vaccines induced long-lasting memory response, as evidenced by detection of persistent gE-specific Long-Lived Plasma Cells (LLPCs) and memory T cells four months after final immunization. These findings underscore the potential of our mRNA-LNP-based vaccine candidates in generating potent immune responses against VZV, offering promising prospects for their clinical development as an effective prophylactic vaccine against herpes zoster. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
3. First evidence of free-living Naegleria species in recreational lakes of Alberta, Canada.
- Author
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Dey, Rafik, Dlusskaya, Elena, Oloroso, Mariem, and Ashbolt, Nicholas J.
- Subjects
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SPECIES , *ENVIRONMENTAL reporting , *LAKES , *NAEGLERIA fowleri , *WATER management - Abstract
Rising temperatures are increasing environmental habitats for thermotolerant pathogens, such as the so-called ‘brain-eating amoeba’, Naegleria fowleri. To the best of our knowledge, however, Naegleria species have not been reported in environmental water sources in Canada. We surveyed popular recreational lakes in Alberta, Canada during the summer bathing period to determine the presence or absence of Naegleria species. While N. fowleri was not isolated in this study, we identified other thermotolerant species, including Naegleria pagei, Naegleria gruberi, Naegleria jejuensis and Naegleria fultoni using culture-based methods, hence indicating the potential conditions to support N. fowleri. Ongoing monitoring and examination of water for pathogenic amoebae is recommended in order to assist in the public health management of water sources. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
4. Preliminary assessment of the State of Fish and Fish Habitat in Fisheries and Oceans Canada's Ontario and Prairie Region.
- Author
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Dey, Cody J., Matchett, Sarah, Doolittle, Andrew, Jung, Jennifer, Kavanagh, Richard, Sobowale, Regina, Schwartz, Todd, and Chu, Cindy
- Subjects
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FISH habitats , *AGRICULTURAL development , *FISHERIES , *WATER quality , *RIPARIAN areas , *WATERSHEDS , *LAND cover - Abstract
With the modernization of the Fisheries Act, DFO committed to producing 'State of Fish and Fish Habitat' (SOFFH) reports for Canada's freshwater ecosystems. As part of this initiative, DFO's Ontario and Prairie (O&P) Region selected the Lake Erie and Lake Ontario drainage basins (Lower Great Lakes Area; LGLA) and the Alberta East Slopes Area (AESA) as focal areas for reporting on in 2023. A Canadian Science Advisory Secretariat meeting was held June 29-30, 2021, to elicit input from academic, environmental practitioners, FFHPP, and DFO Science on the appropriate indicators, metrics, and data that could be used for the O&P SOFFH report. The five indicators selected by DFO O&P were: Biodiversity, Water Quality, Connectivity, Land Use and Land Cover, and Climate Change. Data for up to six metrics per indicator were summarized for each of the reporting areas. The findings indicated that LGLA has high fish species richness. However, a number of fishes and mussel species have been listed as species at risk. Water quality parameters often exceeded thresholds in areas with the greatest urban and agricultural development, and there was also an absence of natural riparian cover in those areas. Ninety-two per cent of the barriers within the LGLA are known to prevent fish movement. Forward and backward bioclimatic velocities were found to be highest in the assessment units surrounding the Greater Toronto Area and assessment units in the Lake Ontario basin. Flood forecasts showed variable changes in the location and heights of 100-yr floods with climate change. The AESA has lower fish species richness relative to the LGLA and a correspondingly, lower number of species at risk. Water quality parameters were often consistent with guidelines for the protection of aquatic life and connectivity varied amongst watercourses in the area. Land use and land cover in the AESA showed high spatial variance, with rangeland and crops in the southeast and trees and snow/ice in the western and northeastern regions. Due to the presence of large national and provincial parks, entire assessment units were protected in the mountainous regions of AESA. Forward bioclimatic velocities were two times faster and flood heights were also higher in the AESA compared to LGLA. This report provides insight into the SOFFH within the AESA and LGLA. However, limited data were available for some metrics, resulting in high uncertainty related to the SOFFH in some assessment units. As such, we identified key data gaps and limitations of the selected indicators and metrics. This information could be used to prioritize spatial extents and items for future research and monitoring projects. The process outlined in this report demonstrates how a quantitative approach to reporting on the SOFFH could be applied by DFO in other regions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
5. A Centralized Approach to Training Peer Counselors: 3 Years of Progress.
- Author
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de Rosenroll, David A. and Dey, Cal
- Abstract
Describes a three-year project (1985-88) which established a training center for peer counseling that serves three school districts. An evaluation of the citywide project is reported, and the limitations of centralized training are discussed, along with speculations about expanding services and populations. (TE)
- Published
- 1990
6. Cloaking and Quantum Stealth: The Science Behind Invisibility.
- Author
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DUTTA, RAJARSHI, GANGULY, SHREYA, DEY, ANKIKA, DUTTA, DEBASMITA, DAS, SAYANTAN, SIL, SAYANTAN, and PRAMANIK, TANAY
- Subjects
INVISIBILITY ,PHYSICISTS ,MILITARY science - Abstract
Invisibility has always been a field of human interest, which was never possible in the maximum of the physicists' eyes. But the old ideas are fading away as Quantum Stealth is coming into existence as a new opportunity for cloaking. The technology is supposed to be used in military warfare and defence scenarios in Canada, especially satisfying the purpose of camouflage. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
7. Research priorities for the management of freshwater fish habitat in Canada.
- Author
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Dey, Cody J., Rego, Adam I., Bradford, Michael J., Clarke, Keith D., McKercher, Katherine, Mochnacz, Neil J., Paiva, Alex de, Ponader, Karin, Robichaud, Lisa, Winegardner, Amanda K., Berryman, Court, Blanchfield, Paul J., Boston, Christine M., Braun, Doug, Brownscombe, Jacob W., Burbidge, Christopher, Campbell, Stuart, Cassidy, Alicia, Chu, Cindy, and Cooke, Steven J.
- Subjects
- *
FISH habitats , *FRESHWATER fishes , *SCIENTIFIC knowledge , *AQUATIC resources , *HABITAT conservation , *HABITATS , *FISHERY management , *FRESHWATER habitats - Abstract
Effective management of freshwater fish habitat is essential to supporting healthy aquatic ecosystems and sustainable fisheries. In Canada, recent changes to the Fisheries Act enhanced the protection of fish habitat, but application of those provisions relies on sound scientific evidence. We employed collaborative research prioritization methods to identify scientific research questions that, if addressed, would significantly advance the management of freshwater fish habitat in Canada. This list was generated by a diverse group of freshwater fish experts, including substantial contributions from practitioners who administer provisions of the Fisheries Act. The research questions generated in this study identify priority topics for future research, while highlighting issues that could be addressed with different funding models. As a result, this study should support evidence-based management of Canada's aquatic resources by identifying scientific knowledge gaps faced by practitioners, and suggesting mechanisms to address them. Given the important contribution of Canadian freshwater systems to global ecosystem values, and the similar scientific challenges facing fish habitat managers in other jurisdictions, this study is likely to have broad applicability. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
8. Dual-polarimetric descriptors from Sentinel-1 GRD SAR data for crop growth assessment.
- Author
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Bhogapurapu, Narayanarao, Dey, Subhadip, Bhattacharya, Avik, Mandal, Dipankar, Lopez-Sanchez, Juan M., McNairn, Heather, López-Martínez, Carlos, and Rao, Y.S.
- Subjects
- *
CANOLA , *CROP growth , *SYNTHETIC aperture radar , *CROP management , *LEAF development , *TIME series analysis - Abstract
Accurate and high-resolution spatio-temporal information about crop phenology obtained from Synthetic Aperture Radar (SAR) data is an essential component for crop management and yield estimation at a local scale. Crop growth monitoring studies seldom exploit complete polarimetric information contained in dual-pol GRD SAR data. In this study, we propose three polarimetric descriptors: the pseudo scattering-type parameter ( θ c ), the pseudo scattering entropy parameter ( H c ), and the co-pol purity parameter ( m c ) from dual-pol S1 GRD SAR data. We also introduce a novel unsupervised clustering framework using H c and θ c with six clustering zones to represent various scattering mechanisms. We implemented the proposed algorithm on the cloud-based Google Earth Engine (GEE) platform for Sentinel-1 SAR data. We have shown the sensitivity of these descriptors over a time series of data for wheat and canola crops at a test site in Canada. From the leaf development stage to the flowering stage for both crops, the pseudo scattering-type parameter θ c changes by approximately 17°. Moreover, within the entire phenology window, both m c and H c varies by about 0.6. The effectiveness of θ c and H c to cluster the phenological stages for the two crops is also evident from the clustering plot. During the leaf development stage, about 90% of the sampling points were clustered into the low to medium entropy scattering zone for both the crops. Throughout the flowering stage, the entire cluster shifted into the high entropy vegetation scattering zone. Finally, during the ripening stage, the clusters of sample points were split between the high entropy vegetation scattering zone and the high entropy distributed scattering zone, with > 55 % of the sampling points in the high entropy distributed scattering zone. This innovative clustering framework will facilitate the operational use of S1 GRD SAR data for agricultural applications. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
9. On the role of local blockchain network features in cryptocurrency price formation.
- Author
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Dey, Asim K., Akcora, Cuneyt G., Gel, Yulia R., and Kantarcioglu, Murat
- Subjects
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BLOCKCHAINS , *CRYPTOCURRENCIES , *INVESTMENT risk , *BITCOIN , *DATA analysis - Abstract
Cryptocurrencies and the underpinning blockchain technology have gained unprecedented public attention recently. In contrast to fiat currencies, transactions of cryptocurrencies, such as Bitcoin and Litecoin, are permanently recorded on distributed ledgers to be seen by the public. As a result, public availability of all cryptocurrency transactions allows us to create a complex network of financial interactions that can be used to study not only the blockchain graph, but also the relationship between various blockchain network features and cryptocurrency risk investment. We introduce a novel concept of chainlets, or blockchain motifs, to utilize this information. Chainlets allow us to evaluate the role of local topological structure of the blockchain on the joint Bitcoin and Litecoin price formation and dynamics. We investigate the predictive Granger causality of chainlets and identify certain types of chainlets that exhibit the highest predictive influence on cryptocurrency price and investment risk. More generally, while statistical aspects of blockchain data analytics remain virtually unexplored, the paper aims to highlight various emerging theoretical, methodological and applied research challenges of blockchain data analysis that will be of interest to the broad statistical community. The Canadian Journal of Statistics 48: 561–581; 2020 © 2020 Statistical Society of Canada [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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10. Isolation of Legionella pneumophila by Co-culture with Local Ameba, Canada.
- Author
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Dey, Rafik, Mount, Harley, Ensminger, Alex W., Tyrrell, Greg J., Ward, Linda P., and Ashbolt, Nicholas J.
- Subjects
- *
LEGIONELLA pneumophila , *AMOEBA , *LEGIONNAIRES' disease , *HOT tubs , *LEPTOSPIRA interrogans , *PROTOZOA , *PUBLIC health surveillance , *RESEARCH , *BIOLOGICAL evolution , *RESEARCH methodology , *TISSUE culture , *EVALUATION research , *MEDICAL cooperation , *LEGIONELLA , *COMPARATIVE studies , *GENOMES , *EPIDEMICS - Abstract
Legionellosis was diagnosed in an immunocompromised 3-year-old girl in Canada. We traced the source of the bacterium through co-culture with an ameba collected from a hot tub in her home. We identified Legionella pneumophila serogroup 6, sequence type 185, and used whole-genome sequencing to confirm the environmental and clinical isolates were of common origin. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
11. Fire scars reveal source of New England's 1780 Dark Day.
- Author
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McMurry, Erin R., Stainbaugh, Michael C., Cuyette, Richard P., and Dey, Daniel C.
- Subjects
WILDFIRES ,FIRES ,FOREST fires ,GROUND cover fires ,SCARS ,NEW England history - Abstract
Historical evidence suggests that great wildfires burning in the Lake States and Canada can affect atmospheric conditions several hundred miles away (Smith 1950; Wexler 1950). Several 'dark' or 'yellow' days, as such events are commonly called, have been recorded, often with anecdotal or direct evidence pointing to wildfires as the source (Plummer 1912; Ludlum 1972). One such 'dark day' occurred across New England in 1780, a year in which people were technologically unable to confirm the source of such a phenomenon. Here we combine written accounts and fire scar evidence to document wildfire as the likely source of the infamous Dark Day of 1780. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
12. Anthropogenic fire history and red oak forests in south-central Ontario.
- Author
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Dey, Daniel C. and Guyette, Richard P.
- Subjects
FOREST fires ,RED oak ,FOREST ecology - Abstract
The regeneration and dominance of northern, red oak (Quercus rubra L.) has been associated with fire throughout eastern North America. Red oak in central Ontario grows near the northern edge of its distribution in mixed hardwood-coniferous forests under mesic conditions where it competes with more shade-tolerant species. We hypothesized that the abundance of red oak in these stands was largely the result of anthropogenic burning and natural fires, which would favor the regeneration and recruitment of northern red oak over such shade-tolerant species as sugar maple (Acer saccharum Marsh.). Fire histories dating from the mid-1600s were constructed by dendrochronological methods from fire scars on stumps, trees, and natural remnants of red pine (Pinus resinosa Ait.), white pine (Pinus strobus L.), and red oak at six sites in south-central Ontario. Fire histories of the sites are characterized by abrupt changes in fire interval. As much or more variance in fire interval is found within sites as is found among sites. Differences in the mean fire interval among sites are related to the density and migration of historic aboriginal and European populations. The mean fire interval varied from more than 70 years to six years depending on site location and historic period. The occurrence and abundance of red oak is linked to anthropogenic fire regimes. [ABSTRACT FROM AUTHOR]
- Published
- 2000
- Full Text
- View/download PDF
13. US steel executives take aim at subsidy-backed mills in Canada, EU.
- Author
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Bera, Rijuta Dey
- Subjects
STEEL ,SUBSIDIES ,EXECUTIVES - Abstract
The continuation of protectionist measures such as Section 232 tariffs are necessary to create a "level playing field," since steel producers in Canada and the European Union receive government subsidies for decarbonization, unlike steelmakers in the United States that deploy their own capital, two major US steel producers said during a virtual roundtable. [ABSTRACT FROM AUTHOR]
- Published
- 2021
14. AT A GLANCE: Rio Tinto Q4 copper production falls on lower ore grades.
- Author
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Bera, Rijuta Dey
- Subjects
COPPER mining ,ALUMINUM - Abstract
Rio Tinto's fourth-quarter copper production sank due to lower ore grades, especially at its Kennecott copper mine, while aluminium production took a hit due to unexpected outages in Iceland and Canada during the second half of 2019. [ABSTRACT FROM AUTHOR]
- Published
- 2020
15. Obesity education in the family medicine clerkship: a US and Canadian survey of clerkship directors' beliefs, barriers, and curriculum content.
- Author
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Holman, Harland, Dey, Sumi, Drobish, Ian, Aquino, Leora, Davis, Alan T., Koehler, Tracy J., and Malouin, Rebecca
- Subjects
CLINICAL clerkship ,FAMILY medicine ,CURRICULUM ,OBESITY ,WEIGHT gain ,EDUCATION research - Abstract
Background: Despite concerns regarding the increasing obesity epidemic, little is known regarding obesity curricula in medical education. Medical school family medicine clerkships address common primary care topics during clinical training. However, studies have shown that many family physicians feel unprepared at addressing obesity. The purpose of this study was to evaluate factors related to obesity education provided during family medicine clerkships as well as identify future plans regarding obesity education. Methods: Data were collected through the 2017 Educational Research Alliance (CERA) survey of Family Medicine Clerkship Directors (CDs) in the United States and Canada. Survey items included the level of importance of obesity education, teaching methods, barriers to teaching, and obesity related topics taught during the clerkship. Survey data were summarized and analyzed. Results: The survey response rate was 71.2%. The most frequent barrier to teaching obesity related topics was time constraints (89%). The most commonly taught topics were co-morbid conditions (82.1%), diet (76.9%), and exercise (76.9%). The least commonly taught topics were addressed less than 30% of the time, and included cultural aspects, obesity bias, medications than can cause weight gain, medications to treat obesity, and bariatric surgery. Over half of CDs (59%) are not planning to change existing curriculum, with 39% planning to add to the current curriculum. The CDs' perceptions of the importance of obesity education were significantly associated with the number of topics covered during clerkship (p < 0.001). No relationship was found between clerkship duration and the number of obesity topics taught. Conclusion: The majority of clerkship directors are planning no changes to their existing curricula which consist of three common topics: obesity related co-morbid conditions, diet, and exercise. While time was the largest self-rated barrier in teaching obesity related topics, clerkship duration didn't impact the number of topics taught. However, the relative amount of importance placed by CDs upon obesity education was significantly associated with the number of topics covered during clerkship. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
16. Earthwise: Pictograph rock.
- Author
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Dey, Mavis
- Subjects
AGAWA Site (Ont.) ,ROCK paintings ,PICTURE-writing - Abstract
Describes picture writings made by a shaman from the Ojibwa Indian tribe on the face of the Agawa Rock cliff located at the Lake Superior Provincial Park in Ontario. Shaman's use of hematite to create the red paint used in the drawings; History of the drawings; Canadian artist Selwyn Dewdney's discovery of the rock paintings in the 1950s.
- Published
- 1996
17. Softening US aluminium premium 'limited' by strong fundamentals, sources say.
- Author
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Bera, Rijuta Dey
- Subjects
ALUMINUM ,STEEL ,TARIFF ,PRESSURE - Abstract
The United States' Midwest P1020 aluminium premium fell slightly on Tuesday May 21 due to downward pressure days after the US removed Section 232 tariffs against Canada and Mexico. [ABSTRACT FROM AUTHOR]
- Published
- 2019
18. US Midwest aluminium premium rebounds on tight supply.
- Author
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Bera, Rijuta Dey
- Subjects
ALUMINUM prices - Abstract
The P1020 Midwest aluminium premium in the United States edged higher on Friday April 5 amid tightening supply and a wide contango on the London Metal Exchange. [ABSTRACT FROM AUTHOR]
- Published
- 2019
19. Big show in a small town.
- Author
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Dey, Myrna
- Subjects
- *
PERFORMING arts - Abstract
Focuses on the staging of a gala in Saskatchewan by a troupe of professional performers during the month of November. Performance description; Connections with the community.
- Published
- 1994
20. Morphological indicators of stock quality and field performance of red oak (Quercus rubra L.) seedlings underplanted in a central Ontarioshelterwood
- Author
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Parker, W. C. and Dey, D. C.
- Subjects
RED oak ,FORESTS & forestry - Abstract
The value of initial stem diameter near the root collar, shoot length and number of first-order lateral roots (FOLR) as morphological indicators of stock quality and field performance was examined for bareroot (1+0, undercut) red oak (Quercus rubra L.) underplanteded in a shelterwood in central Ontario. These three attributes were measured onmore than 400 seedlings prior to planting, and their relationship with height and basal diameter growth two years after planting was determined using correlation and regression analysis. Initial diameter, shoot length and number of FOLR were positively and significantly correlated with second-year height and diameter. These relationships werestrongest for diameter, but this variable explained less than 25% ofthe total variation in growth. Of the three indicators, diameter wasalso the best predictor of several physical characteristics of root systems a two years after planting. Initial diameter was significantly correlated with root volume, root area and lateral root, taproot and total root dry mass. Weaker relationships existed between initial shoot length and number of FOLR and second-year root system features. Stem diameter two years after planting was more strongly related to root volume, area and dry mass than was initial diameter, the probableresult of adjustment in root-shoot balance of planting stock to the shelterwood environment. [ABSTRACT FROM AUTHOR]
- Published
- 1997
21. Land, Lots of Land.
- Author
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Dey, Myrna
- Subjects
- *
CITIES & towns , *GRAIN elevators , *POPULATION - Abstract
Describes Kamsack, Saskatchewan. Distance to the nearest commercial airport; Reasons the town is shrinking; Removal of grain elevators; Decrease seen in the population; Reduction in the value of houses and property.
- Published
- 2003
22. Genetic counselors' research dissemination practices and attitudes.
- Author
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Blanche E, Wainstein T, Dey A, and Elliott AM
- Subjects
- Humans, Attitude of Health Personnel, Information Dissemination methods, Female, Male, Canada, Adult, Genetic Counseling, Counselors
- Abstract
Benefits have been demonstrated to disseminating aggregate research results to all relevant audiences, including study participants. Despite this, many health researchers face barriers in dissemination to broad audiences and returning aggregate results to participants is not commonly practiced. Due to their research presence and training in communication, genetic counselors can lead in implementing best practices in this area. We explored genetic counselors' current practices and opinions regarding educating study participants and wider audiences of research findings. We distributed a survey of 32 multiple-choice and open-ended questions to National Society of Genetics Counselors (NSGC) and Canadian Association of Genetic Counsellors (CAGC) members. Most respondents (90.1%, n = 128/142) identified with a responsibility to disseminate their research findings to a broad audience and identified several associated benefits. All respondents saw value in communicating aggregate results to study participants, although over half (53.2%, n = 66/124) had never done so. Genetic counselors reported resource and knowledge barriers to research dissemination. Despite expertise in education and communication, genetic counselors face similar barriers as other researchers toward broad dissemination of research. Formal training and professional guidelines specific to research dissemination practices will equip genetic counselors to reach broader audiences and maximize the impact of research findings., (© 2023 The Authors. Journal of Genetic Counseling published by Wiley Periodicals LLC on behalf of National Society of Genetic Counselors.)
- Published
- 2024
- Full Text
- View/download PDF
23. SF2Former: Amyotrophic lateral sclerosis identification from multi-center MRI data using spatial and frequency fusion transformer.
- Author
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Kushol R, Luk CC, Dey A, Benatar M, Briemberg H, Dionne A, Dupré N, Frayne R, Genge A, Gibson S, Graham SJ, Korngut L, Seres P, Welsh RC, Wilman AH, Zinman L, Kalra S, and Yang YH
- Subjects
- Humans, Canada, Magnetic Resonance Imaging methods, Neuroimaging, Brain diagnostic imaging, Brain pathology, Amyotrophic Lateral Sclerosis diagnostic imaging
- Abstract
Amyotrophic Lateral Sclerosis (ALS) is a complex neurodegenerative disorder characterized by motor neuron degeneration. Significant research has begun to establish brain magnetic resonance imaging (MRI) as a potential biomarker to diagnose and monitor the state of the disease. Deep learning has emerged as a prominent class of machine learning algorithms in computer vision and has shown successful applications in various medical image analysis tasks. However, deep learning methods applied to neuroimaging have not achieved superior performance in classifying ALS patients from healthy controls due to insignificant structural changes correlated with pathological features. Thus, a critical challenge in deep models is to identify discriminative features from limited training data. To address this challenge, this study introduces a framework called SF
2 Former, which leverages the power of the vision transformer architecture to distinguish ALS subjects from the control group by exploiting the long-range relationships among image features. Additionally, spatial and frequency domain information is combined to enhance the network's performance, as MRI scans are initially captured in the frequency domain and then converted to the spatial domain. The proposed framework is trained using a series of consecutive coronal slices and utilizes pre-trained weights from ImageNet through transfer learning. Finally, a majority voting scheme is employed on the coronal slices of each subject to generate the final classification decision. The proposed architecture is extensively evaluated with multi-modal neuroimaging data (i.e., T1-weighted, R2*, FLAIR) using two well-organized versions of the Canadian ALS Neuroimaging Consortium (CALSNIC) multi-center datasets. The experimental results demonstrate the superiority of the proposed strategy in terms of classification accuracy compared to several popular deep learning-based techniques., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)- Published
- 2023
- Full Text
- View/download PDF
24. Motor cortex functional connectivity is associated with underlying neurochemistry in ALS.
- Author
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Dey A, Luk CC, Ishaque A, Ta D, Srivastava O, Krebs D, Seres P, Hanstock C, Beaulieu C, Korngut L, Frayne R, Zinman L, Graham S, Genge A, Briemberg H, and Kalra S
- Subjects
- Humans, Diffusion Tensor Imaging methods, Canada, Magnetic Resonance Imaging methods, Amyotrophic Lateral Sclerosis, Motor Cortex, Neurochemistry
- Abstract
Objective: To identify structural and neurochemical properties that underlie functional connectivity impairments of the primary motor cortex (PMC) and how these relate to clinical findings in amyotrophic lateral sclerosis (ALS)., Methods: 52 patients with ALS and 52 healthy controls, matched for age and sex, were enrolled from 5 centres across Canada for the Canadian ALS Neuroimaging Consortium study. Resting-state functional MRI, diffusion tensor imaging and magnetic resonance spectroscopy data were acquired. Functional connectivity maps, diffusion metrics and neurometabolite ratios were obtained from the analyses of the acquired multimodal data. A clinical assessment of foot tapping (frequency) was performed to examine upper motor neuron function in all participants., Results: Compared with healthy controls, the primary motor cortex in ALS showed reduced functional connectivity with sensory (T=5.21), frontal (T=3.70), temporal (T=3.80), putaminal (T=4.03) and adjacent motor (T=4.60) regions. In the primary motor cortex, N-acetyl aspartate (NAA, a neuronal marker) ratios and diffusion metrics (mean, axial and radial diffusivity, fractional anisotropy (FA)) were altered. Within the ALS cohort, foot tapping frequency correlated with NAA (r=0.347) and white matter FA (r=0.537). NAA levels showed associations with disturbed functional connectivity of the motor cortex., Conclusion: In vivo neurochemistry may represent an effective imaging marker of impaired motor cortex functional connectivity in ALS., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2023
- Full Text
- View/download PDF
25. Genetic counseling research and COVID-19: A lesson in resiliency.
- Author
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Borle K, Dey A, Carrion P, Austin J, and Elliott AM
- Subjects
- Canada, Humans, Pandemics, SARS-CoV-2, COVID-19, Genetic Counseling
- Abstract
GenCOUNSEL is the largest genetic counseling research grant awarded to date and brings together experts in genetic counseling, genomics, law and policy, health services implementation, and health economics research. It is the first project of its kind to examine the genetic counseling issues associated with the clinical implementation of genome-wide sequencing (exome and genome sequencing). GenCOUNSEL is a Canadian-based, multi-method research study that takes place over a variety of sites, including non-clinical, clinical, and laboratory research sites and includes the training of undergraduate and graduate students. The COVID-19 pandemic will likely have a lasting impact on genetic counseling service delivery, research, and training. Almost every aspect of the GenCOUNSEL research project has been impacted by the COVID-19 pandemic. Here we describe how our research recruitment strategies, methods, resource allocation, and training capacity have been affected. We discuss ways that we have adapted to the pandemic including revision of our research methods and work to understand the barriers in order to optimize opportunities. We finish with take-home messages to fellow researchers highlighting the importance of resiliency in genetic counseling research., (© 2021 National Society of Genetic Counselors.)
- Published
- 2021
- Full Text
- View/download PDF
26. Scientific Overview: CSCI-CITAC Annual General Meeting and Young Investigators' Forum 2015.
- Author
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Zhao EY, Zhou TE, Benesch MG, Dey A, Liu P, Steadman PE, Zaslavsky K, Schneider R, and Kuzyk A
- Subjects
- Canada, Cardiology methods, Education, Medical, Humans, Internal Medicine methods, Medical Oncology methods, Ontario, Translational Research, Biomedical, Universities, Biomedical Research methods, Research Personnel
- Abstract
The 2015 Annual General Meeting of The Canadian Society of Clinician Investigators (CSCI) and Clinician Investigator Trainee Association of Canada/Association des Cliniciens-Chercheurs en Formation du Canada (CITAC/ACCFC) was held in Toronto November 23-25, 2015, in conjunction with The University of Toronto Clinician Investigator Program Research Day. The theme for this year's meeting was "It takes a village" and the focus was the various support systems necessary to train a successful clinician scientist. The meeting featured an opening presentation by Dr. Vincent Dumez and workshops by Dr. Peter Nickerson, Dr. Jane Aubin, Dr. Kelly Warmington and Dr. Norman Rosenblum, and MD/PhD trainees Nardin Samuel, Kevin Wang and Kirill Zaslavsky. The keynote speakers were Dr. David Malkin (Hospital for Sick Children) who received the CSCI-RCPSC Henry Friesen Award, Dr. Brent Richards (McGill University) who received the Joe Doupe Award and Ernesto Shiffrin (Lady Davis Institute) who received the Distinguished Scientist Award. As always, the conference showcased outstanding scientific presentations from clinician investigator trainees from across the country at the Young Investigators' Forum. The research topics, which ranged from basic sciences to clinical medicine and translational work, are summarized in this review. Over 90 abstracts were presented at this year's meeting during two poster sessions, with several of the outstanding abstracts selected for oral presentations.
- Published
- 2016
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27. Comparison of the properties of phosphoglucomutase from muscle of turbot (Reinhardtius hippoglossoides, Greenland Halibut) and witch flounder (Glyptocephalus cynoglossus) from the Northwest Atlantic and the Gulf of St. Lawrence.
- Author
-
Dey AC
- Subjects
- Amino Acids analysis, Animals, Canada, Kinetics, Phosphoglucomutase isolation & purification, Seawater, Species Specificity, Fishes metabolism, Muscles enzymology, Phosphoglucomutase metabolism
- Abstract
1. Phosphoglucomutase from muscle of turbot and witch has been purified and the properties studied from two regions of the Northwest Atlantic and the Gulf of St. Lawrence. 2. The enzyme, purified 157 fold from turbot and 164 fold from witch had specific activities of 596 and 475 U/mg/min respectively. 3. The M.W. and pH optimum of the enzyme from both species were 63,500 and 7500; and 63,000 and 7800 for the Northwest Atlantic and the Gulf samples respectively. 4. The amino acid contents and responses towards different inhibitory agents were different for the enzyme from the Gulf than the Northwest Atlantic samples. 5. The findings compares well with the genetic analysis of the electrophoretic properties of the enzyme in relation to stock discrimination of the two species.
- Published
- 1982
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