The University of Winnipeg
  • Winnipeg, MB, Canada
Recent publications
Background The rapid evolution of seminal fluid proteins (SFPs) has been suggested to be driven by adaptations to postcopulatory sexual selection (e.g. sperm competition). However, we have recently shown that most SFPs evolve rapidly under relaxed selective pressures. Given the role of SFPs in competition for fertilization phenotypes, like the ability to transfer and store sperm and the modulation of female receptivity and ovulation, the prevalence of selectively relaxed SFPs appears as a conundrum. One possible explanation is that selection on SFPs might be relaxed in terms of protein amino acid content, but adjustments of expression are essential for post-mating function. Interestingly, there is a general lack of systematic implementation of gene expression perturbation assays to monitor their effect on phenotypes related to sperm competition. Results We successfully manipulated the expression of 16 SFP encoding genes using tissue-specific knockdowns (KDs) and determined the effect of these genes’ perturbation on three important post-mating phenotypes: female refractoriness to remating, defensive (P1), and offensive (P2) sperm competitive abilities in Drosophila melanogaster . Our analyses show that KDs of tested SFP genes do not affect female refractoriness to remating and P2, however, most gene KDs significantly decreased P1. Moreover, KDs of SFP genes that are selectively constrained in terms of protein-coding sequence evolution have lower P1 than KDs of genes evolving under relaxed selection. Conclusions Our results suggest a more predominant role, than previously acknowledged, of variation in gene expression than coding sequence changes on sperm competitive ability in D. melanogaster .
The work presented here reports the greener synthesis of polyurea (GPUa) via in‐situ solvent‐free precipitation polymerization of toluene diisocyanate (TDI) (used as monomer) and water. The divalent manganese [Mn(II)] ions were incorporated into GPUa to form Mn(II)‐GPUa to enhance its applicability. The structure of GPUa and Mn(II)‐GPUa was validated by Fourier‐transform infrared and proton nuclear magnetic resonance spectral techniques. The morphology along with the elemental analysis of GPUa and Mn(II)‐GPUa was assessed by X‐ray diffraction analysis and field emission scanning electron microscopy along with energy‐dispersive X‐ray spectroscopy. Thermal degradation behavior and stability of GPUa and Mn(II)‐GPUa were investigated by thermo‐gravimetric, differential thermal, differential scanning calorimetry, and integral procedure decomposition temperature analysis. Furthermore, the batch adsorption method was used to examine the adsorption behavior of Mn(II)‐GPUa. The study's results indicated that Mn(II)‐GPUa might be used as an eco‐friendly, thermally stable material and adsorbent, making it suitable as an effective dye adsorbent for wastewater treatment. The current work is aligned with Green chemistry principles (Principles 1, 2, 3, 4, 5, 6, 8, and 12).
Using research on the political economy of the music industries, interviews with independent musicians about their lived experiences, and the authors' experience participating in government copyright consultations in Canada, this article discusses how the market power of major music companies, and their capture of the policy-making process through lobbying, has made copyright reform an extremely limited avenue for remedying the variety of hardships facing musicians in the streaming media era. Against the continued consolidation and concentration of power within the music industries, we explore a case study of Edmonton Public Library’s Capital City Records as an alternative model that may inspire further initiatives that advocate for artists and users. We conclude by discussing a commons-based, public infrastructure and governance model that could serve as a tool to circumvent uneven power dynamics in the music industries, facilitate stronger music communities, and provide sustainable livelihoods for working musicians in Canada.
Background We compared risks of nonmelanoma skin cancers (NMSCs) and melanoma preceding and following a diagnosis of inflammatory bowel disease (IBD) and to evaluate the effect of thiopurines and anti-tumor necrosis factor α (anti-TNF-α) on skin cancer risk in IBD. Methods This was a retrospective, historical cohort study using the population-based University of Manitoba IBD Epidemiology Database (11 228 IBD cases and 104 725 matched controls) linked to the Manitoba Cancer Registry. Logistic and Cox regression analyses were performed to calculate skin cancer risks prior to and after IBD diagnosis. Results Persons with ulcerative colitis (UC) were more likely to have basal cell carcinoma (BCC) predating their UC diagnosis (odds ratio, 1.32; 95% confidence interval [CI], 1.08-1.60). Risks of squamous cell carcinoma (SCC), other NMSCs, or melanoma prior to IBD diagnosis were not significantly increased. Post-IBD diagnosis, risks of BCC (hazard ratio, 1.53; 95% CI, 1.37-1.70) and SCC (hazard ratio, 1.61; 95% CI, 1.29-2.01) were significantly increased across all IBD groups except for SCC in UC. There was no significant association between melanoma and IBD post–IBD diagnosis. The risks of BCC and melanoma were increased in thiopurine and anti-TNF users, and risk of SCC was increased in only thiopurine users. Nested cohort analysis of persons with IBD with censoring at both thiopurines and anti-TNF use confirmed a higher baseline risk of BCC and no effect on SCC, comparable to pre-IBD diagnosis findings. Conclusions The risk of BCC preceding a diagnosis of UC is higher than in non-UC controls, compared with a generally increased risk of all NMSCs post–IBD diagnosis. Thiopurine and anti-TNF therapy increase the risks for skin cancers in persons with IBD after their diagnoses.
In our original paper, we proposed a new species, Homo bodoensis, to replace the problematical taxa Homo heidelbergensis and Homo rhodesiensis, with the goal of streamlining communication about human evolution in the Chibanian. We received two independent responses. Given their substantial overlap, we provide one combined reply. In this response: (1) we are encouraged that the primary proposal in our paper, to discontinue the use of H. heidelbergensis (as a junior synonym to Homo neanderthalensis) due to its' nomenclatural problems, is acknowledged. (2) we provide additional clarification about the rules governing taxonomic nomenclature as outlined by the International Code of Zoological Nomenclature and join the growing calls for a revision to these rules. (3) we discuss further why H. rhodesiensis should be abandoned, particularly in light of the current sensitivity to using culturally inappropriate names. We conclude that H. bodoensis is a better solution than the proposed alternatives.
Background: The coronavirus pandemic necessitated the rapid transition to virtual care. At a 24-h walk-in mental health Crisis Response Centre (CRC) in Winnipeg, Canada we adapted crisis mental health assessments to be offered virtually while the crisis centre also remained open to in person visits. Little is known about the sustainability of virtual visits in the presence of comparable in person care, and which visits are more likely to be done virtually, particularly in the crisis setting. Methods: An analysis of visits to the CRC from the first local lockdown on March 19, 2020 through the third local wave with heightened public health restrictions in June 2021. Analysis of Variance was used to compare the proportion of visits occurring virtually (telephone or videoconference) during the first wave of heightened public health restrictions (lockdown 1) and subsequent lockdowns as well as the in-between periods. A binary logistic regression examined visit, sociodemographic and clinical factors associated with receipt of a virtual visit compared to an in person visit over the first year of the pandemic. Results: Out of 5,357 visits, 993 (18.5%) occurred virtually. There was a significant difference in proportion of virtual visits across the pandemic time periods (F(4, 62) = 8.56, p < .001). The proportion of visits occurring virtually was highest during lockdown 1 (mean 32.6% by week), with no differences between the other time periods. Receipt of a virtual visit was significantly associated with daytime weekday visits, age, non-male gender, living further away from the CRC, no prior year contact with the CRC, and visits that did not feature suicidal behaviour, substance use, psychosis or cognitive impairment. Conclusions: A large proportion of virtual care occurring at the outset of the pandemic reflects public anxiety and care avoidance paired with health system rapid transformation. The use of virtual visits reduced over subsequent pandemic periods but was sustained at a meaningful level. Specific visit, sociodemographic and clinical characteristics are more likely to be present in visits occurring virtually compared to those in person. These results can help to inform the future planning and delivery of virtual crisis care.
Guidance from Health Canada to limit highly processed foods (HPF) seeks to ensure that Canadians remain within intake recommendations for nutrients of concern. However, HPF can contribute to dietary requirements of specific populations. The Canadian Nutrition Society and Institute for the Advancement of Food and Nutritional Sciences convened speakers for a Food for Health workshop in 2021 to provide evidence and perspectives from government, industry, and healthcare on reasons for advocating limits and potential unintended consequences of limiting HPF, and implications and necessity of HPF in clinical settings. This paper discusses advantages and disadvantages of HPF explored at this workshop.
This paper draws from the literature on security networks and policy transfer to examine the privatization of social control in the downtown of Winnipeg, Manitoba. We show how a consortium of public and private entities transferred a security policy from Minneapolis, Minnesota, to Winnipeg, Manitoba, leading to the creation of the Downtown Community Safety Partnership (DCSP) that essentially gave the urban governance and security keys to the city to private organizations. The policy transfers jurisdiction and a policing mentality to a network led by a major corporate player in downtown Winnipeg, True North Sports and Entertainment (TNSE), which is mobilizing social and economic capital to expand the social control that occurs inside its corporate hockey rink to downtown Winnipeg. Situating our contribution in the literature on privatization of criminal justice, we examine the policy itself and the effects of the DCSP model of urban security. Invoking the notion of urban growth machines, we also situate these developments in a discussion of urban capital expansion and entrenchment.
The application of dynamic phasors (DPs) in overhead line protection was investigated. Equations to estimate the fault loop inductance and resistance were derived using the principles of DPs. A systematic amplitude comparator‐based line distance protection scheme was developed using the equations derived to estimate the fault loop inductance and resistance. A least‐squares‐based DP extraction method that mitigates the effect of decaying dc components was used to extract the DPs and their derivatives from time‐domain signals. The performance of the algorithm was investigated using a power system simulated in PSCAD/EMTDC. Testing under different fault scenarios with different fault locations, fault resistance, and fault inception angles showed that the proposed line distance protection scheme is capable of operating successfully for forward and reverse faults, short circuits and high impedance faults, evolving fault conditions, and under a wide range of source impedance ratios. The operating time of the proposed scheme was compared with the standard quadrilateral relay, and the results showed that the operating times of the proposed scheme are faster for close‐in phase‐to‐ground faults but not significantly improved for phase‐to‐phase and three‐phase faults compared to the standard quadrilateral distance relay.
We present ΔO2/Ar‐based estimates of mixed layer net community production (NCP) from three summer cruises in the North American Arctic and Subarctic oceans. Coupling shipboard underway and discrete observations with output from an ocean circulation model, we correct the NCP estimates for vertical mixing fluxes impacting the surface O2 budget. Large positive mixing fluxes, exceeding 100 mmol O2 m⁻² d⁻¹, were derived in regions of strong wind‐driven mixing, such as the Labrador Sea (LS), and in the physically‐dynamic Canadian Arctic Archipelago. In contrast, flux corrections were small (<10 mmol O2 m⁻² d⁻¹, on average) in the density‐stratified Baffin Bay, where mixing was low, and parts of the well‐mixed Hudson Strait (HS), where vertical O2 gradients were weak. The distribution of corrected NCP was highly heterogenous across the study region, reflecting varying contributions of nutrient supply, freshwater input and sea ice dynamics. Elevated NCP was apparent in the LS, HS, and nearshore regions influenced by glacial meltwater and recent ice retreat. Low NCP and localized net heterotrophy occurred in Baffin Bay, and near strong freshwater and organic matter sources in Hudson Bay and the Queen Maud Gulf. A multiple linear regression model developed using available oceanographic data explained ∼58% of the observed NCP variability. Our work demonstrates the spatially explicit influence of vertical mixing on ΔO2/Ar‐based NCP calculations across varied hydrographic conditions, and presents a novel approach to account for this process. This study contributes new knowledge of biological productivity distributions in under‐sampled, rapidly changing, high‐latitude waters.
Barth Syndrome (BTHS) is a rare X‐linked genetic disorder caused by mutation in the TAFAZZIN gene. Tafazzin (Taz) deficiency in BTHS patients results in an increased risk of infections. Mesenchymal stem cells (MSCs) are well known for their immune‐inhibitory function. We examined how Taz‐deficiency in murine MSCs impact their ability to modulate the function of lipopolysaccharide (LPS)‐activated wild type (WT) B lymphocytes. MSCs from tafazzin knockdown (TazKD) mice exhibited a reduction in mitochondrial cardiolipin compared to wild type (WT) MSCs. However, mitochondrial bioenergetics and membrane potential were unaltered. In contrast, TazKD MSCs exhibited increased reactive oxygen species generation and increased glycolysis. The increased glycolysis was associated with an elevated proliferation, phosphatidylinositol‐3‐kinase expression and expression of the immunosuppressive markers indoleamine‐2,3‐dioxygenase, cytotoxic T‐lymphocyte‐associated protein 4, interleukin‐10, and cluster of differentiation 59 compared to controls. Inhibition of glycolysis with 2‐deoxyglucose attenuated the TazKD‐mediated increased expression of cytotoxic T‐lymphocyte‐associated protein 4 and interleukin‐10. When co‐cultured with LPS‐activated WT B cells, TazKD MSCs inhibited B cell proliferation and growth rate and reduced B cell secretion of immunoglobulin M compared to controls. In addition, co‐culture of LPS‐activated WT B cells with TazKD MSCs promoted B cell differentiation toward interleukin‐10 secreting plasma cells and B regulatory cells compared to controls. The results indicate that Taz deficiency in MSCs promote reprogramming of activated B lymphocytes toward immunosuppressive phenotypes.
LINKED CONTENT This article is linked to Hawthorne et al papers. To view these articles, visit https://doi.org/10.1111/apt.17042 and https://doi.org/10.1111/apt.17077
Boulder placement is a common method to restore degraded instream habitats by enhancing habitat complexity. This experimental study is the foremost attempt to systematically investigate the influence of rock-ramp boulder placement with varying boulder concentration and flow rate on habitat hydraulic complexity metrics, including the kinetic energy gradient and modified recirculation metrics. By adding boulders to a reach, the modified recirculation metric increased by one order of magnitude for all boulder concentrations. Based on the studied metrics, boulder placement with the highest boulder concentration (λ = 8.3%) resulted in the greatest habitat hydraulic complexity. A set of relationships of moderate strength were proposed to predict the metrics in reaches with boulders by having information about only boulder concentration, habitat characteristic size, and reach-averaged flow characteristics. Based on the available data from the literature, boulder placement especially at higher concentrations may provide suitable habitats for several riverine fish species. Further studies are needed to establish a reliable linkage between the metrics and instream species, to test a wider variety of parameters for verifying and improving the range of applicability of the proposed relationships, and to find the structural configuration at which the habitat complexity is maximized or optimized for a certain species.
One reason for the persistence of racial inequality may be anticipated dissimilarity with racial outgroups. In the present research, we explored the impact of perceived similarity with White and Black targets on facial identity recognition accuracy. In two studies, participants first completed an ostensible personality survey. Next, in a Learning Phase, Black and White faces were presented on one of three background colours. Participants were led to believe that these colours indicated similarities between them and the target person in the image. Specifically, they were informed that the background colours were associated with the extent to which responses by the target person on the personality survey and their own responses overlapped. In actual fact, faces were randomly assigned to colour. In both studies, non‐Black participants (Experiment 1) and White participants (Experiment 2) showed better recognition of White than Black faces. More importantly in the present context, a positive linear effect of similarity was found in both studies, with better recognition of increasingly similar Black and White targets. The independent effects for race of target and similarity, with no interaction, indicated that participants responded to Black and White faces according to category membership as well as on an interpersonal level related to similarity with specific targets. Together these findings suggest that while perceived similarity may enhance identity recognition accuracy for Black and White faces, it may not reduce differences in facial memory for these racial categories.
The joint models for longitudinal and survival data have recently received significant attention in medical and epidemiological studies. Joint models typically combine linear mixed effects models for repeated measurement data and Cox models for survival time. When we are jointly modelling the longitudinal and survival data, variable selection and efficient estimation of parameters are especially important for performing reliable statistical analyses, both of which are currently lacking in the literature. In this paper we discuss the pretest and shrinkage estimation methods for jointly modelling longitudinal data and survival time data when some of the covariates in both longitudinal and survival components may not be relevant for predicting survival times. In this situation, we fit two models: the full model that contains all the covariates and the subset model that contains a reduced number of covariates. We combine the full model estimators and the estimators that are restricted by a linear hypothesis to define pretest and shrinkage estimators. We provide their numerical mean squared errors (MSE) and relative MSE. We show that if the shrinkage dimension exceeds two, the risk of the shrinkage estimators is strictly less than that of the full model estimators. Our proposed methods are illustrated by extensive simulation studies and a real-data example.
Myocardial infarction (MI) is a life-threatening disorder that occurs due to a prolonged limitation of blood supply to the heart muscles, and which requires an immediate diagnosis to prevent death. To detect MI, cardiologists utilize in particular echocardiography, which is a non-invasive cardiac imaging that generates real-time visualization of the heart chambers and the motion of the heart walls. These videos enable cardiologists to identify almost immediately regional wall motion abnormalities (RWMA) of the left ventricle (LV) chamber, which are highly correlated with MI. However, data acquisition is usually performed during emergency which results in poor-quality and noisy data that can affect the accuracy of the diagnosis. To address the identified problems, we propose in this paper an innovative, real-time and fully automated model based on convolutional neural networks (CNN) to early detect MI in a patient’s echocardiography. Our model is a pipeline consisting of a 2D CNN that performs data preprocessing by segmenting the LV chamber from the apical four-chamber (A4C) view, followed by a 3D CNN that performs a binary classification to detect MI. The pipeline was trained and tested on the HMC-QU dataset consisting of 162 echocardiography. The 2D CNN achieved 97.18% accuracy on data segmentation, and the 3D CNN achieved 90.9% accuracy, 100% precision, 95% recall, and 97.2% F1 score. Our detection results outperformed existing state-of-the-art models that were tested on the HMC-QU dataset for MI detection. This work demonstrates that developing a fully automated system for LV segmentation and MI detection is efficient and propitious.
Economic theory postulates that taxes and alternative tax policies have different impacts on economic growth. Some scholars have argued that economic growth can result in an increase in total tax revenues and its ratio to GDP. Our study investigates the impact of economic growth on total tax revenues and different tax share ratios in transitional economies. We find strong support for the hypothesis that economic growth leads to an increase in total tax revenue-to-GDP ratio. We also find that economic growth has led to, and facilitated, changes in the relative shares of different tax sources in transition countries over time differently thus allowing these countries to streamline their taxes and properly plan for and alter their tax system accordingly.
Septo-optic dysplasia (SOD) and optic nerve hypoplasia (ONH) cause congenital visual impairment. Their aetiology is mostly unknown. Our aim was to investigate the prevalence of selected ophthalmological features in patients with these disorders. A chart review was performed on patients with SOD/ONH. Ophthalmological data were extracted. There were 102 patients (56 males). The median age at the end of the study was 12.7 years. Best-corrected visual acuity ranged from normal to no light perception. Bilateral ONH was more common than unilateral ONH. Strabismus (85%) and to a lesser extent nystagmus (52%) were both very common in our cohort. Patients with esotropia had worse visual acuity than those who had exotropia. The presence of nystagmus was more likely in cases with bilateral ONH. Therefore, patients with SOD/ONH may have normal visual acuity. Many have strabismus, which may cause amblyopia thereby further decreasing visual acuity. Nystagmus occurs commonly and its presence typically indicates bilateral ONH.
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2,378 members
Laura Sokal
  • Faculty of Education
Christopher J. Henry
  • Department of Applied Computer Science
Christopher Leo
  • Department of Political Science
Alberto Civetta
  • Department of Biology
Quinn E Fletcher
  • Department of Biology
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515 Portage Ave, R3B 2E9, Winnipeg, MB, Canada
Head of institution
Dr. Annette Trimbee
Website
http://uwinnipeg.ca/
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(204) 786-7811