Dominique Petit

Hôpital du Sacré-Coeur de Montréal, Montréal, Quebec, Canada

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Publications (74)331.47 Total impact

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    ABSTRACT: The aim of this study was to examine whether short sleep duration is associated with poor receptive vocabulary at age 10 years. In the Quebec Longitudinal Study of Child Development, parents reported their children's nocturnal sleep duration annually from ages 2.5 to 10 years, and children were assessed for receptive vocabulary using the Peabody Picture Vocabulary Test—Revised (PPVT-R) at ages 4 and 10 years. Groups with distinct nocturnal sleep duration trajectories were identified and the relationships between sleep trajectories and poor PPVT-R performance were characterized. In all, 1192 children with available sleep duration and PPVT-R data participated in this epidemiological study. We identified four longitudinal nocturnal sleep trajectories: short persistent sleepers (n = 72, 6.0%), short increasing sleepers (n = 47, 3.9%), 10-h sleepers (n = 628, 52.7%) and 11-h sleepers (n = 445, 37.3%). In all, 14.8% of the children showed poor PPVT-R performance at age 10 years. Nocturnal sleep trajectories and poor PPVT-R performance at age 10 were associated significantly (P = 0.003). After adjusting for baseline receptive vocabulary performance at age 4 and other potential confounding variables, logistic regression analyses suggest that, compared to 11-h sleepers, the odds ratio of presenting poor receptive vocabulary at age 10 was 2.67 [95% confidence interval (CI): 1.24–5.74, P = 0.012] for short persistent sleepers and 1.66 (95% CI: 1.06–2.59, P = 0.026) for 10-h sleepers. These results corroborate previous findings in early childhood, and indicate that short sleep duration is associated with poor receptive vocabulary during middle childhood.
    No preview · Article · Jan 2016 · Journal of Sleep Research
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    ABSTRACT: A large proportion of patients with idiopathic rapid eye movement sleep behavior disorder (iRBD) develop a synucleinopathy, mostly Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. Therefore, identifying markers of neurodegeneration in iRBD could have major implications. We aimed to assess the usefulness of electroencephalography (EEG) spectral analysis performed during wakefulness for predicting the development of a neurodegenerative disease in iRBD. Fifty-four iRBD patients, 28 of whom developed Parkinson's disease, multiple system atrophy, or dementia with Lewy bodies (mean follow-up: 3.5 years), and 30 healthy controls underwent at baseline a resting-state waking EEG recording, neurological exam, and neuropsychological assessment. Absolute and relative spectral powers were analyzed for 5 frequency bands in frontal, central, parietal, temporal, and occipital regions. The slow-to-fast [(δ + θ)/(β1 + β2)] power ratio for each of the 5 cortical regions and the dominant occipital frequency were calculated as an index of cortical slowing. Patients who developed disease showed higher absolute delta and theta power in all 5 cortical regions compared to disease-free patients and controls. The slow-to-fast power ratio was higher in all regions in patients who developed disease than in the 2 other groups. Moreover, patients who developed disease had a slower dominant occipital frequency compared to controls. The only significant difference observed between disease-free iRBD patients and controls was higher absolute delta power in frontal and occipital regions in iRBD patients. Specific EEG abnormalities were identified during wakefulness in iRBD patients who later developed a synucleinopathy. EEG slowing is a promising marker of neurodegeneration in iRBD patients.
    No preview · Article · Oct 2015 · Neurobiology of aging
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    ABSTRACT: The basal forebrain cholinergic system, which is impaired in early Alzheimer's disease, is more crucial for the activation of rapid-eye-movement (REM) sleep electroencephalogram (EEG) than it is for wakefulness. Quantitative EEG from REM sleep might thus provide an earlier and more accurate marker of the development of Alzheimer's disease in subjects with mild cognitive impairment (MCI) subjects than that from wakefulness. To assess the superiority of the REM sleep EEG as a screening tool for preclinical Alzheimer's disease, 22 subjects with amnestic MCI (a-MCI; 63.9 ± 7.7 years), 10 subjects with nonamnestic MCI (na-MCI; 64.1 ± 4.5 years) and 32 controls (63.7 ± 6.6 years) participated in the study. Spectral analyses of the waking EEG and REM sleep EEG were performed and the [(delta + theta)/(alpha + beta)] ratio was used to assess between-group differences in EEG slowing. The a-MCI subgroup showed EEG slowing in frontal lateral regions compared to both na-MCI and control groups. This EEG slowing was present in wakefulness (compared to controls) but was much more prominent in REM sleep. Moreover, the comparison between amnestic and nonamnestic subjects was found significant only for the REM sleep EEG. There was no difference in EEG power ratio between na-MCI and controls for any of the 7 cortical regions studied. These findings demonstrate the superiority of the REM sleep EEG in the discrimination between a-MCI and both na-MCI and control subjects. © EEG and Clinical Neuroscience Society (ECNS) 2015.
    No preview · Article · Aug 2015 · Clinical EEG and neuroscience: official journal of the EEG and Clinical Neuroscience Society (ENCS)
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    ABSTRACT: Background: Despite its high prevalence, relatively little is known about the pathophysiology of somnambulism. Increasing evidence indicates that somnambulism is associated with functional abnormalities during wakefulness and that sleep deprivation constitutes an important drive that facilitates sleepwalking in predisposed patients. Here, we studied the neural mechanisms associated with somnambulism using Single Photon Emission Computed Tomography (SPECT) with 99mTc-Ethylene Cysteinate Dimer (ECD), during wakefulness and after sleep deprivation. Methods: Ten adult sleepwalkers and twelve controls with normal sleep were scanned using 99mTc-ECD SPECT in morning wakefulness after a full night of sleep. Eight of the sleepwalkers and nine of the controls were also scanned during wakefulness after a night of total sleep deprivation. Between-group comparisons of regional cerebral blood flow (rCBF) were performed to characterize brain activity patterns during wakefulness in sleepwalkers. Results: During wakefulness following a night of total sleep deprivation, rCBF was decreased bilaterally in the inferior temporal gyrus in sleepwalkers compared to controls. Conclusions: Functional neural abnormalities can be observed during wakefulness in somnambulism, particularly after sleep deprivation and in the inferior temporal cortex. Sleep deprivation thus not only facilitates the occurrence of sleepwalking episodes, but also uncovers patterns of neural dysfunction that characterize sleepwalkers during wakefulness.
    Full-text · Article · Aug 2015 · PLoS ONE
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    ABSTRACT: Sleepwalkers often complain of excessive daytime somnolence. Although excessive daytime somnolence has been associated with cognitive impairment in several sleep disorders, very few data exist concerning sleepwalking. This study aimed to investigate daytime cognitive functioning in adults diagnosed with idiopathic sleepwalking. Fifteen sleepwalkers and 15 matched controls were administered the Continuous Performance Test and Stroop Colour-Word Test in the morning after an overnight polysomnographic assessment. Participants were tested a week later on the same neuropsychological battery, but after 25 h of sleep deprivation, a procedure known to precipitate sleepwalking episodes during subsequent recovery sleep. There were no significant differences between sleepwalkers and controls on any of the cognitive tests administered under normal waking conditions. Testing following sleep deprivation revealed significant impairment in sleepwalkers' executive functions related to inhibitory control, as they made more errors than controls on the Stroop Colour-Word Test and more commission errors on the Continuous Performance Test. Sleepwalkers' scores on measures of executive functions were not associated with self-reported sleepiness or indices of sleep fragmentation from baseline polysomnographic recordings. The results support the idea that sleepwalking involves daytime consequences and suggest that these may also include cognitive impairments in the form of disrupted inhibitory control following sleep deprivation. These disruptions may represent a daytime expression of sleepwalking's pathophysiological mechanisms. © 2015 European Sleep Research Society.
    Full-text · Article · Jun 2015 · Journal of Sleep Research
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    ABSTRACT: Childhood sleepwalking and sleep terrors are 2 parasomnias with a risk of serious injury for which familial aggregation has been shown. To assess the prevalence of sleepwalking and sleep terrors during childhood; to investigate the link between early sleep terrors and sleepwalking later in childhood; and to evaluate the degree of association between parental history of sleepwalking and presence of somnambulism and sleep terrors in children. Sleep data from a large prospective longitudinal cohort (the Quebec Longitudinal Study of Child Development) of 1940 children born in 1997 and 1998 in the province were studied from March 1999 to March 2011. Prevalence of sleep terrors and sleepwalking was assessed yearly from ages 11/2 and 21/2 years, respectively, to age 13 years through a questionnaire completed by the mother. Parental history of sleepwalking was also queried. The peak of prevalence was observed at 11/2 years for sleep terrors (34.4% of children; 95% CI, 32.3%-36.5%) and at age 10 years for sleepwalking (13.4%; 95% CI, 11.3%-15.5%). As many as one-third of the children who had early childhood sleep terrors developed sleepwalking later in childhood. The prevalence of childhood sleepwalking increases with the degree of parental history of sleepwalking: 22.5% (95% CI, 19.2%-25.8%) for children without a parental history of sleepwalking, 47.4% (95% CI, 38.9%-55.9%) for children who had 1 parent with a history of sleepwalking, and 61.5% (95% CI, 42.8%-80.2%) for children whose mother and father had a history of sleepwalking. Moreover, parental history of sleepwalking predicted the incidence of sleep terrors in children as well as the persistent nature of sleep terrors. These findings substantiate the strong familial aggregation for the 2 parasomnias and lend support to the notion that sleepwalking and sleep terrors represent 2 manifestations of the same underlying pathophysiological entity.
    Full-text · Article · May 2015
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    ABSTRACT: Context: An association between an adjuvanted (AS03) A/H1N1 pandemic vaccine and narcolepsy has been reported in Europe. Objective: To assess narcolepsy risk following administration of a similar vaccine in Quebec. Design: Retrospective population-based study. Setting: Neurologists and lung specialists in the province were invited to report narcolepsy cases to a single reference centre. Population: Patients were interviewed by two sleep experts and standard diagnostic tests were performed. Immunization status was verified in the provincial pandemic influenza vaccination registry. Main Outcome Measures: Confirmed narcolepsy with or without cataplexy with onset of excessive daytime sleepiness between January 1 st, 2009, and December 31 st, 2010. Relative risks (RRs) were calculated using a Poisson model in a cohort analysis, by a self-controlled case series (SCCS) and a case-control method. Results: A total of 24 cases were included and overall incidence rate was 1.5 per million person-years. A cluster of 7 cases was observed among vaccinated persons in the winter 2009-2010. In the primary cohort analysis, 16-week post-vaccination RR was 4.32 (95% CI: 1.50-11.12). RR was 2.07 (0.70-6.17) in the SCCS, and 1.48 (0.37-7.03) using the case-control method. Estimates were lower when observation was restricted to the period of pandemic influenza circulation, and tended to be higher in persons,20 years old and for cataplexy cases. Conclusions: Results are compatible with an excess risk of approximately one case per million vaccine doses, mainly in persons less than 20 years of age. However, a confounding effect of the influenza infection cannot be ruled out.
    Full-text · Article · Sep 2014 · PLoS ONE
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    ABSTRACT: Idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) is a well-documented risk factor for synucleinopathies such as Parkinson disease (PD) and dementia with Lewy bodies (DLB). Moreover, approximately 50% of iRBD patients have mild cognitive impairment (MCI). The purpose of our study was to investigate waking electroencephalogram (EEG) abnormalities specific to iRBD patients with MCI. Forty-two polysomnographically confirmed iRBD patients, including 23 iRBD [+]MCI patients 19 patients without MCI (iRBD [-]MCI), and 37 healthy subjects participated in the study. All participants underwent a complete neuropsychologic assessment for MCI diagnosis and a waking quantitative EEG recording. iRBD [+]MCI patients had a higher slow-to-fast frequency ratio than iRBD [-]MCI patients and controls in the parietal, temporal, and occipital regions. iRBD [+]MCI patients also had higher relative θ power in the parietal, temporal, and occipital regions and lower relative α power in the occipital region compared to iRBD [-]MCI patients and controls. Moreover, iRBD [+]MCI patients had higher relative θ power in the frontal and central areas and lower relative β power in the central, parietal, and temporal regions compared to controls. The dominant occipital frequency also was slower in iRBD [+]MCI patients compared to controls. No between-group differences were observed between iRBD [-]MCI patients and controls. In iRBD patients, only those with concomitant MCI showed waking EEG slowing in the posterior cortical regions, providing a potential marker for an increased risk for developing DLB or PD.
    Full-text · Article · Sep 2013 · Sleep Medicine
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    ABSTRACT: Sleepwalkers often complain of excessive daytime somnolence (EDS). Our retrospective study aimed to document the presence of EDS in a substantial sample of sleepwalkers and to explore the contribution of other sleep disorders, nocturnal sleep disruption, and sleep depth to the alteration of their daytime vigilance. Seventy adult sleepwalkers and 70 control subjects completed the Epworth Sleepiness Scale (ESS). Sleepwalkers also were studied for one night in the sleep laboratory. We compared the sleep profiles of 32 somnolent vs 38 nonsomnolent sleepwalkers and investigated the relationship between ESS scores and sleep-related variables. No differences were found in polysomnographic (PSG) parameters. Slow-wave activity (SWA) also was similar in the two subgroups. Sleepwalkers' ESS scores were not correlated with their body mass index (BMI) or periodic limb movements during sleep (PLMS) index, but they tended to be negatively correlated with indices of respiratory events. The EDS reported by adult sleepwalkers does not appear to be explained by the presence of concomitant sleep disorders or PSG signs of nocturnal sleep disruption. These results raise the possibility that EDS is part of the sleepwalking phenotype and that it is linked to its underlying pathophysiology.
    Full-text · Article · Aug 2013 · Sleep Medicine
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    ABSTRACT: Objectives: To determine the relative contributions of genetic and environmental factors on daytime and nighttime continuous sleep duration at 6, 18, 30, and 48 months of age, and to identify different subgroups of children who followed different daytime and nighttime sleep duration trajectories and to investigate their etiology. Methods: The current study included 995 twins (405 monozygotic and 586 dizygotic) of the Quebec Newborn Twin Study recruited from the birth records of the Quebec Statistics Institute. Daytime and nighttime sleep was assessed through maternal reports at 6, 18, 30, and 48 months of age. A semiparametric modeling strategy was used to estimate daytime and nighttime sleep duration trajectories. Quantitative genetic models were used to examine to what extent genetic and environmental factors influenced daytime and nighttime continuous sleep duration. Results: Genetic modeling analyses revealed environmental influences for all daytime sleep duration trajectories. In contrast, strong genetic influences were found for consolidated nighttime sleep duration (except at 18 months and for the short-increasing sleep duration trajectory). Conclusions: This is the first indication that early childhood daytime sleep duration may be driven by environmental settings, whereas the variance in consolidated nighttime sleep duration is largely influenced by genetic factors with a critical environmental time-window influence at ∼18 months.
    Full-text · Article · May 2013 · PEDIATRICS
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    ABSTRACT: Somnambulism, or sleepwalking, can give rise to a wide range of adverse consequences and is one of the leading causes of sleep-related injury. Accurate diagnosis is crucial for proper management and imperative in an ever-increasing number of medicolegal cases implicating sleep-related violence. Unfortunately, several widely held views of sleepwalking are characterised by key misconceptions, and some established diagnostic criteria are inconsistent with research findings. The traditional idea of somnambulism as a disorder of arousal might be too restrictive and a comprehensive view should include the idea of simultaneous interplay between states of sleep and wakefulness. Abnormal sleep physiology, state dissociation, and genetic factors might explain the pathophysiology of the disorder.
    Full-text · Article · Mar 2013 · The Lancet Neurology
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    Chapter: Autores

    Full-text · Chapter · Dec 2011
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    ABSTRACT: Sex differences in the effects of sleep duration on dietary intake and eating behaviours were examined prospectively in relation to overweight/obesity at ages 6 and 7. Using data from a representative sample (QLSCD 1998-2010) of children born in the province of Québec (Canada), 1106 children were followed to age 6 and 1015 to 7years. Average nocturnal sleep duration was surveyed annually from 2.5-6years, food-frequency and eating behaviour questionnaires were administered at age 6, and body weight and height were measured at 6 and 7years. Associations were examined longitudinally and mediation examined with adjustments for potential confounders. In boys and girls, shorter sleep duration patterns were associated significantly with less favourable dietary intakes at 6years: boys consumed vegetables and fruits less frequently and meats/alternatives more frequently than boys with longer sleep patterns; and girls consumed vegetables, fruits and milk products less frequently and soft-drinks more frequently than girls with longer sleep patterns. However, boys with shorter sleep patterns were also more likely to eat at irregular hours or to eat too much/fast at 6years. These behaviours, and not dietary intake, mediated an inverse association between sleep duration and overweight/obesity in boys. Sleep duration did not associate with any problem eating behaviours or overweight/obesity in girls. Shorter sleep in early childhood appears to associate with problematic eating behaviours in boys and diet quality in both sexes, regardless of an association with overweight/obesity. This is important for public health and should be considered in relation to other diet-related diseases.
    Full-text · Article · Dec 2011 · Journal of Sleep Research

  • No preview · Article · Sep 2011

  • No preview · Article · Sep 2011 · Sleep Medicine
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    ABSTRACT: The objectives were (1) to assess associations between sleep consolidation at 6, 18 and 30 months and language skills at 18, 30, and 60 months; and (2) to investigate the genetic/environmental etiology of these associations. Longitudinal study of a population-based twin cohort. 1029 twins from the Quebec Newborn Twin Study. Sleep consolidation was derived from parental reports of day/night consecutive sleeping durations. Language skills were assessed with the MacArthur Communicative Development Inventory at 18 and 30 months and the Peabody Picture Vocabulary Test at 60 months. The day/night sleep ratio decreased significantly from 6 to 30 months. The 6- and 18-month ratios were negatively correlated with subsequent language skills. Children with language delays at 60 months had less mature sleep consolidation at both 6 and 18 months than children without delays and those with transient early delays. Genetic and regression analyses revealed that the sleep ratio at 6 months was highly heritable (64%) and predicted 18-month (B = -0.06) and 30-month language (B = -0.11) mainly through additive genetic influences (R(Gs) = 0.32 and 0.33, respectively). By contrast, the sleep ratio at 18 months was mainly due to shared environment influences (58%) and predicted 60-month language (B = -0.08) through shared environment influences (R(Cs) = 0.24). Poor sleep consolidation during the first 2 years of life may be a risk factor for language learning, whereas good sleep consolidation may foster language learning through successive genetic and environmental influences.
    Full-text · Article · Aug 2011 · Sleep
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    Full-text · Article · Apr 2011 · Journal of clinical sleep medicine: JCSM: official publication of the American Academy of Sleep Medicine
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    ABSTRACT: Short sleep duration is associated with incidence of overweight and obesity in preadolescent children. The authors performed regression analyses on data from the Quebec Longitudinal Study of Kindergarten Children (1986-1987), a prospective cohort study comprising 1,916 preadolescent children in Canada. The aim was to assess associations between time spent in bed and body mass index reported by mothers after adjusting for numerous confounding factors, such as pubertal status. Time-in-bed and body mass index trajectories were computed using a semiparametric model mixture. Time-in-bed trajectories were classified as short (15% of the preadolescents), 10.5-hour (68%), and 11-hour (17%) sleep-duration trajectories, decreasing over time. Body mass index trajectories were classified as normal weight (68% of the preadolescents), overweight (27%), and obese (5%). The short sleep trajectory was associated with an increased odds ratio of being in the overweight body mass index trajectory (odds ratio (OR)=1.55, 95% confidence interval (CI): 1.39, 1.71) or in the obese body mass index trajectory (OR=3.26, 95% CI: 3.20, 3.29) compared with the 11-hour trajectory. One hour less of sleep per night at 10 years of age was associated with an increased odds ratio of being overweight (OR=1.51, 95% CI: 1.28, 1.76) or obese (OR=2.07; 95% CI: 1.51, 2.84) at 13 years of age.
    Full-text · Article · Feb 2011 · American journal of epidemiology
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    ABSTRACT: A close temporal relationship was shown between the onset of melatonin secretion at night and the worsening of restless legs syndrome (RLS) symptoms, suggesting that melatonin may play a role in the genesis of this phenomenon. To test this hypothesis we studied the effects of the administration of exogenous melatonin and, conversely, the suppression of endogenous melatonin secretion by bright light exposure on the severity of RLS symptoms. Eight RLS subjects were studied in three conditions: at baseline, after administration of melatonin and during bright light exposure. The severity of RLS symptoms was assessed by the suggested immobilization test (SIT), which allows quantification of both sensory and motor manifestations (SIT-PLM) of RLS. Analyses showed a significant increase of SIT-PLM index when subjects received exogenous melatonin compared to both baseline and bright light conditions, but bright light exposure had no effect on leg movements compared to the baseline condition. Analyses also revealed a small but significant decrease in sensory symptoms with bright light exposure compared to baseline. Exogenous melatonin may have a detrimental effect on motor symptoms, and bright light exposure produced small but significant improvement of leg discomfort. The study shows the interest of using the SIT to measure outcome of intervention in RLS. Further studies will be needed to assess the therapeutic value of bright light in RLS.
    No preview · Article · Mar 2010 · Sleep Medicine
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    ABSTRACT: Our objectives were to investigate the developmental trajectories of nighttime sleep duration and hyperactivity over the preschool years and to identify the risk factors associated with short nighttime sleep duration and high hyperactivity scores. Nighttime sleep duration and hyperactivity were measured yearly by questionnaires administered to mothers of 2057 children from age 1.5 to 5 years. Developmental trajectories of nighttime sleep duration and hyperactivity throughout early childhood were analyzed to determine interassociations. A multinomial logistic regression was performed to determine which factors among selected child, maternal, and family characteristics and parental practices surrounding sleep periods in early childhood were associated with short nighttime sleep duration and high hyperactivity scores. The trajectories of nighttime sleep duration and hyperactivity were significantly associated. The odds ratio (OR) of reporting short nighttime sleep duration was 5.1 for highly hyperactive children (confidence interval [CI]: 3.2-7.9), whereas the OR of reporting high hyperactivity scores was 4.2 for persistently short sleepers (CI: 2.7-6.6). The risk factors for reporting short nighttime sleep duration and high hyperactivity scores were (1) being a boy, (2) having insufficient household income, (3) having a mother with a low education, and (4) being comforted outside the bed after a nocturnal awakening at 1.5 years of age. The risk of short nighttime sleep duration in highly hyperactive children is greater than the risk of high hyperactivity scores in short sleepers. Preventive interventions that target boys living in adverse familial conditions could be used to address these concomitant behavioral problems.
    Full-text · Article · Oct 2009 · PEDIATRICS

Publication Stats

3k Citations
331.47 Total Impact Points

Institutions

  • 1993-2015
    • Hôpital du Sacré-Coeur de Montréal
      • Center for Advanced Research in Sleep Medicine
      Montréal, Quebec, Canada
  • 1992-2015
    • Université de Montréal
      • Department of Psychiatry
      Montréal, Quebec, Canada