Now showing items 1-20 of 527

    • Rethinking property in c\a\n\a\d\a

      Blackwell, Adrian; Devine, Bonnie; Kaewan Dang, Tiffany; Fortin, David; reid stewart, luugigyoo patrick (Small Walker Press and Salon für Kunstbuch, 2021-11-10)
      Indigenous and settler architects and urbanists reimagine Canadian cities and discuss property division as the hinge between settler colonialism and architecture/urban form. The conversation is informed by the issue 12-13 of the journal Scapegoat: Architecture / Landscape / Political Economy titled c\a\n\a\d\a: delineating nation state capitalism edited by David Fortin and Adrian Blackwell. Rethinking property in c\a\n\a\d\a transcribes a virtual round table conversation co-hosted by the Research Centre in Interdisciplinary Arts and Creative Culture (Centre for Studies in Arts and Culture, Marilyn I. Walker School of Fine and Performing Arts, Brock University) and the Salon für Kunstbuch (Vienna, Austria) on 10 November 2021.
    • Early teen-work assemblages and embedded dependence

      Raby, Rebecca; Lehmann, Wolfgang (Brill, 2021)
      This chapter aims to trouble the common linkage often made between work, independence and adulthood by emphasizing how young workers are embedded in human and non-human collectivities of interwoven dependences. We focus on two 16-year-old participants from conventional interview and photo elicitation interview data with 32 Canadian young people discussing their first part-time jobs, to we recognize how our participants, and indeed all of us, are embedded ‘in the midst of an open-ended swirl of extensions and supplementations’ (Lee 2001, 115). These entangled dependences can activate privilege; they also bolster the illusion of individual independence and autonomy. The intent of this chapter is to work with ideas from Actor Network Theorist Nick Lee and from Deleuze and Guattari to reveal this illusion, for we are all enmeshed in dependency. We particularly focus on four components of teen-work assemblages: family; time, space and bodies; tools/machinery, practices and roles; and capitals/money.
    • Interrupted time series analysis of Canadian legal cannabis sales during the COVID‐19 pandemic

      Armstrong, Michael J.; Cantor, Nathan; Smith, Brendan T.; Jesseman, Rebecca; Hobin, Erin; Myran, Daniel T. (Wiley, 2022-03-22)
      Introduction: There were repeated reports of increased cannabis sales, use, and health impacts in Canada during the COVID-19 pandemic. However, it was unclear whether the increases were due to pandemic effects or industry expansion. Methods: We performed interrupted time series regressions of monthly per capita legal cannabis sales from March 2019 to February 2021, first with national averages, then with provincial/territorial data after adjusting for store density. We considered two interruption alternatives: January 2020, when product variety increased; and March 2020, when pandemic restrictions began. Results: The provincial/territorial regression with the January interruption explained R2 = 69.6% of within-jurisdiction variation: baseline monthly per capita sales growth averaged $0.21 (95% CI: 0.15, 0.26), sales immediately dropped in January by $1.02 (95% CI: -1.67, -0.37), and monthly growth thereafter increased by $0.16 (95% CI: 0.06, 0.25). With the March interruption, the regression instead explained 68.7% of variation: baseline sales growth averaged $0.14 (95% CI: 0.06, 0.22), there was no immediate drop, and growth thereafter increased by $0.22 per month, (95% CI: 0.08, 0.35). Discussion: Increasing cannabis sales during the pandemic was consistent with pre-existing trends and increasing store numbers. The extra increased growth was more aligned with January’s new product arrivals than with March’s pandemic measures, though the latter cannot be ruled out. Conclusions: We found little evidence of pandemic impacts on Canada’s aggregate legal cannabis sales. We therefore caution against attributing increased population-level cannabis use or health impacts primarily to the pandemic.
    • Constructs of childhood, generation and heroism in editorials on young people's climate change activism: Their mobilisation and effects

      Raby, Rebecca; Sheppard, Lindsay C. (Wiley, 2021)
      We analyse the effects of constructions and mobilisations of childhood, generation and girl heroism in 30 Canadian editorials written in response to 2019 climate change protests. We discuss how the editorials strategically position—and sometimes dismiss—young activists through discourses of childhood innocence, becoming and social participation. Second, we focus on how the editorials mobilise generation to emphasise either generational division or cross‐generational solidarity. Finally, we problematise the editorials' concentration on individualised girl heroism. We thus contextualise and deconstruct truth statements around age, generation and heroism, emphasising instead their effects and the potential for certain narratives to better recognise the diversity and solidarity in climate change activism.
    • Dynamic functional brain network connectivity during pseudoword processing relates to children’s reading skill

      Panda, Erin J.; Kember, Jonah; Emami, Zahra; Nayman, Candace; Valiante, Taufik A.; Pang, Elizabeth W. (Elsevier, 2022)
      Learning to read requires children to link print (orthography) with its corresponding speech sounds (phonology). Yet, most EEG studies of reading development focus on emerging functional specialization (e.g., developing increasingly refined orthographic representations), rather than directly measuring the functional connectivity that links orthography and phonology in real time. In this proof-of-concept study we relate children's reading skill to both orthographic specialization for print (via the N170, also called the N1, event related potential, ERP) and orthographic-phonological integration (via dynamic/event-related EEG phase synchronization – an index of functional brain network connectivity). Typically developing English speaking children (n = 24; 4–14 years) and control adults (n = 20; 18–35 years) viewed pseudowords, consonants and unfamiliar false fonts during a 1-back memory task while 64-channel EEG was recorded. Orthographic specialization (larger N170 for pseudowords vs. false fonts) became more left-lateralized with age, but not with reading skill. Conversely, children's reading skill correlated with functional brain network connectivity during pseudoword processing that requires orthography-phonology linking. This was seen during two periods of simultaneous low frequency synchronization/high frequency desynchronization of posterior-occipital brain network activity. Specifically, in stronger readers, left posterior-occipital activity showed more delta (1–3Hz) synchronization around 300–500 ms (simultaneous with gamma 30–80 Hz desynchronization) and more gamma desynchronization around 600–1000 ms (simultaneous with theta 3–7Hz synchronization) during pseudoword vs. false font processing. These effects were significant even when controlling for age (moderate – large effect sizes). Dynamic functional brain network connectivity measures the brain's real-time sound-print linking. It may offer an under-explored, yet sensitive, index of the neural plasticity associated with reading development. Reading requires us to link visual print with speech sound processing. Yet, most EEG reading research explores functional specialization not integration. While children's age relates to ERPs (N170) associated with print specialization. Children's reading skill relates to real-time functional brain network connectivity. EEG phase synchrony = sensitive index of functional integration during reading.
    • Roots, Rights and Risk: Canada, Childhood and the COVID-19 Global Pandemic

      Ciotti, Sarah; Moore, Shannon A.; Connolly, Maureen; Newmeyer, Trent (2021)
      The COVID-19 global pandemic highlights pre-existing inequities as well as the challenge of ensuring the protection of children’s human rights in countries like Canada that have ratified the United Nations Convention on the Rights of the Child. SARS-CoV-2, referred to as the 2019 novel Coronavirus disease or COVID-19, presents a significant threat to public health. Although children are considered to be low risk of contracting, spreading, and serious complications of the disease, are considerably impacted by COVID-19 government-sanctioned distancing measures. COVID-19 is a persistent public health threat, thus, the long-term consequences are largely unknown. This qualitative research study, a content analysis of online Canadian media reports of COVID-19 and children, engaged transdisciplinary social justice methodology, social constructions of childhood at the intersection of race, socio-economic status, gender, and disability. The findings suggest COVID-19 reinforces the impact of social exclusion and economic disparity on equity-seeking young people and families in Canada.
    • Super-Spreaders or Victims of Circumstance? Childhood in Canadian Media Reporting of the COVID-19 Pandemic: A Critical Content Analysis

      Ciotti, Sarah; Moore, Shannon A.; Connolly, Maureen; Newmeyer, Trent (MDPI, 2022)
      This qualitative research study, a critical content analysis, explores Canadian media reporting of childhood in Canada during the COVID-19 global pandemic. Popular media plays an important role in representing and perpetuating the dominant social discourse in highly literate societies. In Canadian media, the effects of the pandemic on children and adolescents' health and wellbeing are overshadowed by discussions of the potential risk they pose to adults. The results of this empirical research highlight how young people in Canada have been uniquely impacted by the COVID-19 global pandemic. Two dominant narratives emerged from the data: children were presented "as a risk" to vulnerable persons and older adults and "at risk" of adverse health outcomes from contracting COVID-19 and from pandemic lockdown restrictions. This reflects how childhood was constructed in Canadian society during the pandemic, particularly how children's experiences are described in relation to adults. Throughout the pandemic, media reports emphasized the role of young people's compliance with public health measures to prevent the spread of COVID-19 and save the lives of older persons.
    • Phenological and social characterization of three Lasioglossum (Dialictus) species inferred from long-term trapping collections

      Journal of Hymenoptera Research, 2021-12-30
      Detailed social and phenological data collected from nesting aggregations exist for relatively few sweat bee species because nesting aggregations are rarely found in large numbers, even when local populations are highly abundant. This limits researchers’ abilities to assess the social status of many species, which in turn, limits our ability to trace the sequence of evolutionary steps between alternative social states. To address this problem, we demonstrate the utility of rehydrated, pinned specimens from pan trap and netting collections for generating inferences about the phenology and social status of a well-studied sweat bee species, Lasioglossum (Dialictus) laevissimum. A detailed comparison of phenology and reproductive traits, between pinned specimens and those in a previous nesting study, produced similar results for bivoltine foraging activity and eusocial colony organization typical in this species. We then used pinned specimens from monitoring studies to describe, for the first time, the foraging phenology and social behaviour of two additional Dialictus species, L. hitchensi and L. ellisiae. Both L. hitchensi and L. ellisiae each exhibited two peaks in abundance during their breeding seasons, indicating two periods of foraging activity, which correspond to provisioning of spring and summer broods. Differences in body size, wear, and ovarian development of spring and summer females indicated that L. hitchensi is most likely eusocial, while L. ellisiae is either solitary or communal. This study demonstrates that analyses of specimens obtained from flower and pan trap collections can be used for assessing the phenology and social organization of temperate sweat bees in the absence of nesting data. The phenological and social lability of many sweat bee species make them ideal for studying geographic and temporal variability in sociality, and analyses of pan trap collections can make these studies possible when direct observations are impossible.
    • A shared cabin in the woods: The presence and presents of writing in residential academic writing retreats

      Ratković, Snežana; McGinn, Michelle K.; Martinovic, Dragana; McQuirter Scott, Ruth (Equinox Publishing, 2019-11-27)
      In this paper, we investigated a model of academic development based upon a recurring residential academic writing retreat combining individual writing times, workshops, work-in-progress groups and one-on-one consultations with shared meals and informal gatherings in a natural environment. Using a case study research approach, we analysed data accumulated from seven annual residential writing retreats for education scholars. Participants included 39 academics, administrative staff, senior doctoral students and community partners from multiple institutions. We found evidence that the retreats enhanced participants’ knowledge of writing and publishing processes, advanced their academic careers, built scholarly capacity at their institutions and strengthened writing pedagogy. The data indicated that the presence of writing and writers at the residential academic writing retreats generated presents (i.e., gifts) for the participants. The presence of writing time, writing goals and writing activities in the company of other writers were key to the retreat pedagogy. Participants appreciated gifts of time and physical space and described giving and receiving peer feedback and emotional support as forms of gift exchange within the community. The resulting writing strategies, competencies and identities provided the gift of sustainability. The analysis confirmed that this ongoing, immersive, cross-institutional, cross-rank, institutionally funded model of academic development was effective and responsive to the needs of individual scholars.
    • Transfer-Learning-Based Approach for the Diagnosis of Lung Diseases from Chest X-ray Images

      Fan, Rong; Bu, Shengrong (MDPI, 2022)
      Using chest X-ray images is one of the least expensive and easiest ways to diagnose patients who suffer from lung diseases such as pneumonia and bronchitis. Inspired by existing work, a deep learning model is proposed to classify chest X-ray images into 14 lung-related pathological conditions. However, small datasets are not sufficient to train the deep learning model. Two methods were used to tackle this: (1) transfer learning based on two pretrained neural networks, DenseNet and ResNet, was employed; (2) data were preprocessed, including checking data leakage, handling class imbalance, and performing data augmentation, before feeding the neural network. The proposed model was evaluated according to the classification accuracy and receiver operating characteristic (ROC) curves, as well as visualized by class activation maps. DenseNet121 and ResNet50 were used in the simulations, and the results showed that the model trained by DenseNet121 had better accuracy than that trained by ResNet50.
    • Creatine Monohydrate Supplementation Increases White Adipose Tissue Mitochondrial Markers in Male and Female Rats in a Depot Specific Manner

      Ryan, Chantal R.; Finch, Michael S.; Dunham, Tyler C.; Murphy, Jensen E.; Roy, Brian D.; MacPherson, Rebecca E. K. (MDPI AG, 2021-07-14)
      White adipose tissue (WAT) is a dynamic endocrine organ that can play a significant role in thermoregulation. WAT has the capacity to adopt structural and functional characteristics of the more metabolically active brown adipose tissue (BAT) and contribute to non-shivering thermogenesis under specific stimuli. Non-shivering thermogenesis was previously thought to be uncoupling protein 1 (UCP1)-dependent however, recent evidence suggests that UCP1-independent mechanisms of thermogenesis exist. Namely, futile creatine cycling has been identified as a contributor to WAT thermogenesis. The purpose of this study was to examine the efficacy of creatine supplementation to alter mitochondrial markers as well as adipocyte size and multilocularity in inguinal (iWAT), gonadal (gWAT), and BAT. Thirty-two male and female Sprague-Dawley rats were treated with varying doses (0 g/L, 2.5 g/L, 5 g/L, and 10 g/L) of creatine monohydrate for 8 weeks. We demonstrate that mitochondrial markers respond in a sex and depot specific manner. In iWAT, female rats displayed significant increases in COXIV, PDH-E1alpha, and cytochrome C protein content. Male rats exhibited gWAT specific increases in COXIV and PDH-E1alpha protein content. This study supports creatine supplementation as a potential method of UCP1-independant thermogenesis and highlights the importance of taking a sex-specific approach when examining the efficacy of browning therapeutics in future research.
    • Theorizing Community for Sport Management Research and Practice

      Rich, Kyle A.; Spaaij, Ramón; Misener, Laura (Frontiers Media SA, 2021-11-19)
      Community is a context for much research in sport, sport management, and sport policy, yet relatively few authors explicitly articulate the theoretical frameworks with which they interrogate the concept. In this paper, we draw from communitarian theory and politics in order to contribute to a robust discussion and conceptualization of community in and for sport management research and practice. We provide a synthesis of current sport management and related research in order to highlight contemporary theoretical and methodological approaches to studying community. We distinguish between community as a context, as an outcome, as a site for struggle or resistance, as well as a form of regulation or social control. We then advance a critical communitarian agenda and consider the practical implications and considerations for research and practice. This paper synthesizes current research and establishes a foundation upon which sport management scholars and practitioners might critically reflect on community and deliberatively articulate its implications in both future research and practice.
    • Prevalence and Management of Alkyl-Methoxypyrazines in a Changing Climate: Viticultural and Oenological Considerations

      Pickering, Gary J.; Willwerth, Jim; Botezatu, Andreea; Thibodeau, Margaret (MDPI AG, 2021-10-15)
      Alkyl-methoxypyrazines are an important class of odor-active molecules that contribute green, ‘unripe’ characters to wine and are considered undesirable in most wine styles. They are naturally occurring grape metabolites in many cultivars, but can also be derived from some Coccinellidae species when these ‘ladybugs’ are inadvertently introduced into the must during harvesting operations. The projected impacts of climate change are discussed, and we conclude that these include an altered alkyl-methoxypyrazine composition in grapes and wines in many wine regions. Thus, a careful consideration of how to manage them in both the vineyard and winery is important and timely. This review brings together the relevant literatures on viticultural and oenological interventions aimed at mitigating alkyl-methoxypyrazine loads, and makes recommendations on their management with an aim to maintaining wine quality under a changing and challenging climate.
    • Lifestyle decisions and climate mitigation: current action and behavioural intent of youth

      Pickering, Gary J.; Schoen, Kaylee; Botta, Marta (Springer Science and Business Media LLC, 2021-07-26)
      Youth carry the burden of a climate crisis not of their making, yet their accumulative lifestyle decisions will help determine the severity of future climate impacts. We surveyed 17–18 year old’s (N=487) to establish their action stages for nine behaviours that vary in efficacy of greenhouse gas emission (GGE) reduction and the explanatory role of climate change (CC) knowledge, sociodemographic and belief factors. Acceptance of CC and its anthropogenic origins was high. However, the behaviours with the greatest potential for GGE savings (have no children/one less child, no car or first/next car will be electric, eat less meat) have the lowest uptake. Descriptive normative beliefs predicted intent to adopt all high-impact actions, while environmental locus of control, CC scepticism, knowledge of the relative efficacy of actions, religiosity and age were predictive of action stage for several mitigation behaviours (multinomial logistic regression). These findings inform policy and communication interventions that seek to mobilise youth in the global climate crisis response
    • Preliminary Evaluation of an Adaptive Robotic Training Program of the Wrist for Persons with Multiple Sclerosis

      Mannella, Kailynn; Albanese, Giulia A.; Ditor, David; Zenzeri, Jacopo; Holmes, Michael W. R. (MDPI AG, 2021-10-04)
      Robotics can be used to describe wrist kinematics and assess sensorimotor impairments, while the implementation of training algorithms can be aimed at improving neuromuscular control. The purpose of this study was to use a robotic device to develop an adaptive and individualized training program of the distal upper extremity for individuals with multiple sclerosis (MS). This approach included an online assessment of performance aimed at changing the level of assistance/resistance provided during the task. Participants (N = 7) completed a robotic training program that occurred 3 times weekly for 4 weeks. The training protocol consisted of tracking a target moving along a figure by grasping the end-effector of the robotic device and moving it along the trajectory. Outcome measures were assessed pre- and post-intervention. Improvements in performance were quantified by average tracking (p = 0.028) and figural error (p = 0.028), which was significantly reduced by 26% and 43%, respectively. Isometric wrist strength significantly improved post-intervention (flexion: p = 0.043, radial and ulnar deviation: p = 0.028). The results of this work demonstrate that 4-weeks of adaptive robotic training is a feasible rehabilitative program that has the potential to improve distal upper extremity motor accuracy and muscular strength in a MS population.
    • Isotopic evidence of increasing water abundance and lake hydrological change in Old Crow Flats, Yukon, Canada

      MacDonald, Lauren A; Turner, Kevin W; McDonald, Ian; Kay, Mitchell L; Hall, Roland I; Wolfe, Brent B (IOP Publishing, 2021-11-22)
      Lake-rich northern permafrost landscapes are sensitive to changing climate conditions, but ability to track real-time and potentially multiple hydrological responses (e.g. lake expansion, drawdown, drainage) is challenging due to absence of long-term, sustainable monitoring programs in these remote locations. Old Crow Flats (OCF), Yukon, is a Ramsar Wetland of International Importance where concerns about low water levels and their consequences for wildlife habitat and traditional ways of life prompted multidisciplinary studies during the International Polar Year (2007–2008) and led to the establishment of an aquatic ecosystem monitoring program. Here, we report water isotope data from 14 representative thermokarst lakes in OCF, the foundation of the monitoring program, and time-series of derived metrics including the isotope composition of input waters and evaporation-to-inflow ratios for a 13 year period (2007–2019). Although the lakes spanned multiple hydrological categories (i.e. rainfall-, snowmelt- and evaporation-dominated) based on initial surveys, well-defined trends from application of generalized additive models and meteorological records reveal that lakes have become increasingly influenced by rainfall, and potentially waters from thawing permafrost. These sources of input have led to more positive lake water balances. Given the documented role of rainfall in causing thermokarst lake drainage events in OCF and elsewhere, we anticipate increased vulnerability of lateral water export from OCF. This study demonstrates the value of long-term isotope-based monitoring programs for identifying hydrological consequences of climate change in lake-rich permafrost landscapes.
    • Role of the Myokine Irisin on Bone Homeostasis: Review of the Current Evidence

      Kornel, Amanda; Den Hartogh, Danja J.; Klentrou, Panagiota; Tsiani, Evangelia (MDPI AG, 2021-08-24)
      Bone is a highly dynamic tissue that is constantly adapting to micro-changes to facilitate movement. When the balance between bone building and resorption shifts more towards bone resorption, the result is reduced bone density and mineralization, as seen in osteoporosis or osteopenia. Current treatment strategies aimed to improve bone homeostasis and turnover are lacking in efficacy, resulting in the search for new preventative and nutraceutical treatment options. The myokine irisin, since its discovery in 2012, has been shown to play an important role in many tissues including muscle, adipose, and bone. Evidence indicate that irisin is associated with increased bone formation and decreased bone resorption, leading to reduced risk of osteoporosis in post-menopausal women. In addition, low serum irisin levels have been found in individuals with osteoporosis and osteopenia. Irisin targets key signaling proteins, promoting osteoblastogenesis and reducing osteoclastogenesis. The present review summarizes the existing evidence regarding the effects of irisin on bone homeostasis.
    • Development of a dual-factor measure of adolescent mental health: an analysis of cross-sectional data from the 2014 Canadian Health Behaviour in School-aged Children (HBSC) study

      King, Nathan; Davison, Colleen M; Pickett, William (BMJ, 2021-09-30)
      Introduction Studies of adolescent mental health require valid measures that are supported by evidence-based theories. An established theory is the dual-factor model, which argues that mental health status is only fully understood by incorporating information on both subjective well-being and psychopathology. Objectives To develop a novel measure of adolescent mental health based on the dual-factor model and test its construct validity. Design Cross-sectional analysis of national health survey data. Setting and participants Nationally weighted sample of 21 993 grade 6–10 students; average age: 14.0 (SD 1.4) years from the 2014 Canadian Health Behaviour in School-aged Children study. Measures Self-report indicators of subjective well-being (life satisfaction, positive and negative affect), and psychopathology (psychological symptoms and overt risk-taking behaviour) were incorporated into the dual-factor measure. Characteristics of adolescents families, specific mental health indicators and measures of academic and social functioning were used in the assessment of construct validity. Results Proportions of students categorised to the four mental health groups indicated by the dual-factor measure were 67.6% ‘mentally healthy’, 17.5% ‘symptomatic yet content’, 5.5% ‘asymptomatic yet discontent’ and 9.4% ‘mentally unhealthy’. Being mentally healthy was associated with the highest functioning (greater social support and academic functioning) and being mentally unhealthy was associated with the worst. A one-unit increase (ranges=0–10) in peer support (OR 1.19; 95%CI 1.15 to 1.22), family support (OR 1.32; 95%CI 1.28 to 1.36), student support (OR 1.20; 95%CI 1.17 to 1.24) and average school marks (OR 1.18; 95%CI 1.10 to 1.27) increased the odds of being symptomatic yet content versus mentally unhealthy. Mentally healthy youth were the most likely to live with both parents (77% vs ≤65%) and report their family as well-off (62% vs ≤53%). Conclusions We developed a novel, construct valid dual-factor measure of adolescent mental health. This potentially provides a nuanced and comprehensive approach to the assessment of adolescent mental health that is direly needed.
    • Serum MMP‐3 and its association with central arterial stiffness among young adults is moderated by smoking and BMI

      Iannarelli, Nathaniel J.; MacNeil, Adam J.; Dempster, Kylie S.; Wade, Terrance J.; O’Leary, Deborah D. (Wiley, 2021-06-10)
      Central arterial stiffness is an independent predictor of cardiovascular disease. It is characterized by a marked reduction in the elastin-collagen ratio of the arterial wall extracellular matrix (ECM), and is largely the result of degradation of various ECM components. Matrix metalloproteinase-3 (MMP-3) may contribute to central arterial stiffness via its involvement in ECM homeostasis and remodeling. This study examined the association between serum MMP-3 concentrations and central arterial stiffness and potential interactions of MMP-3 and traditional cardiovascular risk factors in a population of healthy young adults. A total of 206 participants (n = 109 females) aged 19–25 years were included in the current study. Central arterial stiffness was measured non-invasively as carotid-femoral pulse wave velocity (cfPWV) (m/s). MMP-3 concentrations (ng/ml) were measured using ELISA techniques. Regression analyses were used to examine the association between cfPWV and MMP-3, adjusting for age, sex, smoking status, body mass index (BMI), instantaneous mean arterial pressure (MAP) and heart rate, and serum C-reactive protein. Interactions between MMP-3 with smoking, BMI, sex, and MAP were analyzed in subsequent regression models. MMP-3 was an independent predictor of cfPWV (β = 0.187, p = 0.007), and significant interactions between MMP-3 and regular smoking (β = 0.291, p = 0.022), and MMP-3 and BMI (β = 0.210, p = 0.013) were observed. Higher serum MMP-3 concentrations were associated with a faster cfPWV and thus, greater central arterial stiffness. Interactions between MMP-3 and smoking, and MMP-3 and BMI may, in part, drive the association between MMP-3 and central arterial stiffness.
    • Characterization of Alzheimer's disease‐like neuropathology in Duchenne's muscular dystrophy using the DBA/2J mdx mouse model

      Hayward, Grant C.; Caceres, Daniela; Copeland, Emily N.; Baranowski, Bradley J.; Mohammad, Ahmad; Whitley, Kennedy C.; Fajardo, Val A.; MacPherson, Rebecca E. K. (Wiley, 2021-11-11)
      Duchenne muscular dystrophy (DMD) is a progressive muscle wasting disorder caused by a mutation in the dystrophin gene. In addition to muscle pathology, some patients with DMD will exhibit cognitive impairments with severity being linked to age and type of genetic mutation. Likewise, some studies have shown that mdx mice display impairments in spatial memory compared with wild-type (WT) controls, while others have not observed any such effect. Most studies have utilized the traditional C57BL/10 (C57) mdx mouse, which exhibits a mild disease phenotype. Recently, the DBA/2J (D2) mdx mouse has emerged as a more severe and perhaps clinically relevant DMD model; however, studies examining cognitive function in these mice are limited. Thus, in this study we examined cognitive function in age-matched C57 and D2 mdx mice along with their respective WT controls. Our findings show that 8- to 12-week-old C57 mdx mice did not display any differences in exploration time when challenged with a novel object recognition test. Conversely, age-matched D2 mdx mice spent less time exploring objects in total as a well as less time exploring the novel object, suggestive of impaired recognition memory. Biochemical analyses of the D2 mdx brain revealed higher soluble amyloid precursor protein b(APPb) and APP in the prefrontal cortex of mdx mice compared with WT, and lower soluble APPa in the hippocampus, suggestive of a shift towards amyloidogenesis and a similar pathogenesis to Alzheimer’s disease. Furthermore, our study demonstrates the utility of the D2 mdx model in studying cognitive impairment.