Quebec

魁北克
  • 文章类型: Journal Article
    Vegetable consumption remains consistently low despite supportive policy and investments across the world. Vegetables are available in great variety, ranging in their processing level, availability, cost, and arguably, nutritional value. A retrospective longitudinal study was conducted in Quebec, Canada to explore pathways of socioeconomic inequity in vegetable expenditure. Data was obtained for consumers who participated in a grocery loyalty program from 2015 to 2017 and linked to the 2016 Canadian census. Vegetable expenditure share (%) was examined as a fraction of the overall food basket and segmented by processing level. Panel random effects and tobit models were used overall and to estimate the stratified analysis by median income split. Consumers allocated 8.35% of their total food expenditure to vegetables, which was mostly allocated to non-processed fresh (6.88%). Vegetable expenditure share was the highest in early winter and lowest in late summer. In the stratified analysis, the low-income group exhibited less seasonal variation, allocated less to fresh vegetables, and spent more on canned and frozen compared to the high-income group. Measures of socioeconomic status were all significant drivers of overall vegetable consumption. Consumers with high post-secondary education in the low-income group spent 2% more on vegetables than those with low education. The complexity of observed expenditure patterns points to a need for more specific vegetable consumption guidelines that include provisions by processing level. Implications for education, marketing, intersectional policies, and the role of government are discussed. Governments can scale present efforts and catalyze health-promoting investments across local, state, national, and global food systems.
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  • 文章类型: Journal Article
    木材密度是结构增长的碳分配的产物,反映了机械支撑和水电导率之间的权衡。我们基于以下假设测试了一个概念框架:微观密度取决于与内生和外生因素的直接和间接关系。木材形成的动力学,包括细胞分裂的时间和速度,细胞增大,和次生壁沉积,从2002年至2016年之间每周从魁北克沿纬度梯度的五个黑云杉林分收集的微核进行评估,加拿大。通过解剖分析和X射线测量记录细胞解剖结构和微密度。我们的结构方程模型解释了树木年轮内80%的微密度变化与壁厚的直接影响(σ=0.61),细胞直径(σ=-0.51),和光周期(σ=-0.26)。木材形成动力学对微密度有间接影响。在较长的细胞壁沉积时间和较短的增大持续时间下,微密度增加。我们的结果填补了理解针叶树微密度变化背后关系的关键空白。我们证明了对环境变化的短期反应可以被调节细胞分化的塑性反应所覆盖。我们的结果指出,木材形成动力学是树木中碳分配的可靠预测指标。
    Wood density is the product of carbon allocation for structural growth and reflects the trade-off between mechanical support and water conductivity. We tested a conceptual framework based on the assumption that micro-density depends on direct and indirect relationships with endogenous and exogenous factors. The dynamics of wood formation, including timings and rates of cell division, cell enlargement, and secondary wall deposition, were assessed from microcores collected weekly between 2002 and 2016 from five black spruce stands located along a latitudinal gradient in Quebec, Canada. Cell anatomy and micro-density were recorded by anatomical analyses and X-ray measurements. Our structural equation model explained 80% of micro-density variation within the tree-ring with direct effects of wall thickness (σ = 0.61), cell diameter (σ = -0.51), and photoperiod (σ = -0.26). Wood formation dynamics had an indirect effect on micro-density. Micro-density increased under longer periods of cell-wall deposition and shorter durations of enlargement. Our results fill a critical gap in understanding the relationships underlying micro-density variation in conifers. We demonstrated that short-term responses to environmental variations could be overridden by plastic responses that modulate cell differentiation. Our results point to wood formation dynamics as a reliable predictor of carbon allocation in trees.
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  • 文章类型: Journal Article
    BACKGROUND: Reports of incidents associated with the misrepresentation of food products as well as the adulteration of their composition leading, at times, to significant public health impacts are being recorded.
    OBJECTIVE: This paper aims at summarizing the outputs of three workshops dedicated to the theme \"Global Understanding of Food Fraud\" (GUFF), held in Quebec City in Canada (April 2017), Beijing in the People\'s Republic of China (October 2017) and Dubai in the United Arab Emirates (October 2018).
    METHODS: Based on the contributions made at these workshops, the paper reviews current knowledge related to food fraud shared by experts and stakeholders representing the food industry sector, food regulators both domestically and internationally and scientists from Academia. It also discusses approaches available to the industry across the food supply chain to predict, prevent, and possibly mitigate food fraud, inclusive of targeted and non-targeted methods of analysis.
    CONCLUSIONS: The paper offers a discussion on areas warranting the mobilization of efforts and resources of the food stakeholder community to reach consistent and accessible guidance on food fraud prevention, validated analytical methods along with an increased emphasis on prevention in food regulatory measures targeting food fraud. Further development is needed to reach consistent and accessible guidance on food fraud prevention, validated analytical methods, along with an emphasis on food fraud prevention.
    CONCLUSIONS: Food fraud is receiving increased attention from consumers, regulators, and industry. International food fraud experts were invited to three workshops. Contributions and conclusions from the workshops are reported and discussed.
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  • 文章类型: Journal Article
    Hospital readmission is a main cost driver for healthcare systems, but existing works often had poor or moderate predictive results. Although the available information differs in different studies, improving prediction is different from the search for important explanatory variables. With large sample size and abundant information, this study explores state-of-the-art machine-learning algorithms and shows their performance in prediction.
    Using administrative data on 1 631 611 hospital stays from Quebec between 1995 and 2012, we predict the probability of 30-day readmission at hospital admission and discharge. We compare the performance between traditional logistic regression, logistic regression with penalization, and more recent machine-learning algorithms such as random forest, deep learning, and extreme gradient boosting.
    After a 10-fold cross-validation on the training set (80% of the data), machine learning produced very good results on a separate hold-out test set (20% of the data). The importance of explanatory variables is not the same for different algorithms. The area under receiver operating characteristic curve (AUC) reached above 0.79 at hospital admission and above 0.88 at hospital discharge. Diagnostic codes, which include many different categories, are among the most predictive variables. Logistic regression with penalization also produced good results, but a standard logistic regression failed without penalization. The good results are confirmed by calibration curves.
    Although the identification of those at highest risk of readmission is just 1 step to preventing hospital readmissions, 30-day readmission is highly predictable with machine learning.
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  • 文章类型: Journal Article
    Given current and projected changes in the climate, the composition of mosquito species is predicted to shift geographically with implications for the transmission dynamics of vector-borne pathogens. Many mosquito species are rarely collected in Canada and their history is poorly understood; thus assessing their potential role as vectors for pathogenesis is difficult. Mosquitoes were collected from four trapping sites in Quebec Province, Canada, from June to September during 2018 and 2019 using BG sentinel traps. From all morphologically identified female mosquitoes, at least one specimen was selected for identification confirmation using the DNA-barcoding technique. Sequences were subjected to alignment and a Neighbor-Joining (NJ) tree was created using Geneious software. In total, 2,752 female mosquitoes belonging to 20 species over five genera: including Aedes (Ae.), Anopheles (An.), Culex (Cx.), Culiseta (Cu.), Coquillettidia (Cq.) were collected. The predominant mosquito was found to be Ae. cinereus. The highest number of mosquito species was captured in July, followed by August, September, and then June. Five genera were characterized by a distinctive set of cytochrome oxidase I (COI) sequences that formed well-supported clusters in the NJ-tree. The presence of Ae.japonicus in Quebec provides an initial look at the distribution of mosquito species in eastern Canada, which may put Canadians at risk of a wider range of arboviruses.
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  • 文章类型: Journal Article
    The effects of climate change on high-latitude forest ecosystems are complex, making forecasts of future scenarios uncertain. The predicted lengthening of the growing season under warming conditions is expected to increase tree growth rates. However, there is evidence of an increasing sensitivity of the boreal forest to drought stress. To assess the influence of temperature and precipitation on the growth of black spruce (Picea mariana), we investigated long-term series of wood anatomical traits on 20 trees from four sites along 600 km, the latitudinal range of the closed boreal forest in Quebec, Canada. We correlated the anatomical traits resolved at intraring level with daily temperature, vapor pressure deficit (VPD), and precipitation during the 1943-2010 period. Tree-ring width, number of cells per ring and cell wall thickness were positively affected by spring and summer daily mean and maximum temperature at the northern sites. These results agree with the well-known positive effect of high temperatures on tree ring formation at high latitudes. However, we captured, for the first time in this region, the latent impact of water availability on xylem traits. Indeed, in all the four sites, cell lumen area showed positive correlations with daily precipitation (mostly at low latitude), and/or negative correlations with daily mean and maximum temperature and VPD (mostly at high latitude). We inferred that drought, due to high temperatures, low precipitations, or both, negatively affects cell enlargement across the closed boreal forest, including the northernmost sites. The production of tracheids with narrower lumen, potentially more resistant to cavitation, could increase xylem hydraulic safety under a warmer and drier climate. However, this would result in lower xylem conductivity, with consequent long-term hydraulic deterioration, growth decline, and possibly lead to tree dieback, as observed in other forest ecosystems at lower latitudes.
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  • 文章类型: Journal Article
    孕前和妊娠期糖尿病(PGDM,GDM)在原住民(北美印第安人)孕妇中的发生率高于加拿大的非土著孕妇。我们评估了PGDM和GDM对围产期和新生儿后死亡率的影响在第一民族与非土著人群中是否不同。
    一项基于人群的出生关联队列研究。
    1996-2010年,魁北克有17090个第一民族和217760个非土著单胎出生,加拿大。
    围产期和新生儿死亡的相对风险(RR)。围产期死亡包括死产和新生儿(产后0-27天)死亡;新生儿后死亡包括28-364天的婴儿死亡。
    PGDM和GDM在原住民中的发生率更高(3.9%和10.7%,分别)与非土著(1.1%和4.8%,分别)孕妇。在第一民族中,PGDM与围产期死亡风险增加的程度更大(RR=5.08[95%CI2.99至8.62],p<0.001;绝对风险(AR)=21.6[8.6-34.6]/1000)与非土著人口(RR=1.76[1.17,2.66],p=0.003;AR=4.2[0.2,8.1]/1000)。PGDM与非土著新生儿死亡风险增加相关(RR=3.46[1.71,6.99],p<0.001;AR=2.4[0.1,4.8]/1000),但不是第一民族(RR=1.16[0.28,4.77],p=0.35)婴儿。调整孕产妇和妊娠特征,协会是相似的。两组GDM均与围产期或新生儿死亡无关。
    这项研究首次揭示,与非土著居民相比,PGDM可能会在更大程度上增加原住民的围产期死亡风险。但可能会大大增加非土著婴儿新生儿后死亡的风险。根本原因尚不清楚,值得进一步研究。我们推测,糖尿病妊娠中血糖控制质量的人群差异和/或高血糖症胎儿毒性的遗传易感性可能是促成因素。
    Both pregestational and gestational diabetes mellitus (PGDM, GDM) occur more frequently in First Nations (North American Indians) pregnant women than their non-Indigenous counterparts in Canada. We assessed whether the impacts of PGDM and GDM on perinatal and postneonatal mortality may differ in First Nations versus non-Indigenous populations.
    A population-based linked birth cohort study.
    17 090 First Nations and 217 760 non-Indigenous singleton births in 1996-2010, Quebec, Canada.
    Relative risks (RR) of perinatal and postneonatal death. Perinatal deaths included stillbirths and neonatal (0-27 days of postnatal life) deaths; postneonatal deaths included infant deaths during 28-364 days of life.
    PGDM and GDM occurred much more frequently in First Nations (3.9% and 10.7%, respectively) versus non-Indigenous (1.1% and 4.8%, respectively) pregnant women. PGDM was associated with an increased risk of perinatal death to a much greater extent in First Nations (RR=5.08[95% CI 2.99 to 8.62], p<0.001; absolute risk (AR)=21.6 [8.6-34.6] per 1000) than in non-Indigenous populations (RR=1.76[1.17, 2.66], p=0.003; AR=4.2[0.2, 8.1] per 1000). PGDM was associated with an increased risk of postneonatal death in non-Indigenous (RR=3.46[1.71, 6.99], p<0.001; AR=2.4[0.1, 4.8] per 1000) but not First Nations (RR=1.16[0.28, 4.77], p=0.35) infants. Adjusting for maternal and pregnancy characteristics, the associations were similar. GDM was not associated with perinatal or postneonatal death in both groups.
    The study is the first to reveal that PGDM may increase the risk of perinatal death to a much greater extent in First Nations versus non-Indigenous populations, but may substantially increase the risk of postneonatal death in non-Indigenous infants only. The underlying causes are unclear and deserve further studies. We speculate that population differences in the quality of glycaemic control in diabetic pregnancies and/or genetic vulnerability to hyperglycaemia\'s fetal toxicity may be contributing factors.
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  • 文章类型: Journal Article
    二次生长是与新细胞的形成相关的过程,所述新细胞在木发生期间在尺寸和壁厚上增加。木材形成的时间动态影响细胞性状,进而影响整个年轮的细胞模式。我们验证了以下假设:细胞直径和细胞壁厚度与其分化阶段的持续时间呈正相关。
    通过微核心产生组织学切片,以评估黑云杉[Piceamariana(Mill。)B.S.P.]。在2002年至2016年之间,每周从魁北克(加拿大)沿纬度梯度的五个地点的50棵树上收集样本。在每日尺度上估计细胞分化的年度内时间动态,并使用改进的vonBertalanffy生长方程拟合了细胞性状与分化持续时间之间的关系。
    在所有网站,在经历较长时间分化的细胞中观察到较大的细胞直径和细胞壁厚度。这种关系是非线性的,下降趋势,偶尔导致明显的渐近线。总的来说,次生壁沉积持续时间长于细胞增大。早晚细胞经历了平均持续12天的扩大阶段,而次生壁厚持续15d。晚木细胞平均扩大7d,次生壁沉积平均发生27d。
    整个树环的细胞大小与细胞形成的时间动态密切相关。在五个研究地点之间观察到类似的关系,表明在该物种的整个纬度分布中共享的木质部形成动力学。细胞分化的持续时间是影响细胞生长和木质部壁增厚的关键因素,从而确定整个年轮上细胞性状的空间变异。
    Secondary growth is a process related to the formation of new cells that increase in size and wall thickness during xylogenesis. Temporal dynamics of wood formation influence cell traits, in turn affecting cell patterns across the tree ring. We verified the hypothesis that cell diameter and cell wall thickness are positively correlated with the duration of their differentiation phases.
    Histological sections were produced by microcores to assess the periods of cell differentiation in black spruce [Picea mariana (Mill.) B.S.P.]. Samples were collected weekly between 2002 and 2016 from a total of 50 trees in five sites along a latitudinal gradient in Quebec (Canada). The intra-annual temporal dynamics of cell differentiation were estimated at a daily scale, and the relationships between cell traits and duration of differentiation were fitted using a modified von Bertalanffy growth equation.
    At all sites, larger cell diameters and cell wall thicknesses were observed in cells that experienced a longer period of differentiation. The relationship was a non-linear, decreasing trend that occasionally resulted in a clear asymptote. Overall, secondary wall deposition lasted longer than cell enlargement. Earlywood cells underwent an enlargement phase that lasted for 12 d on average, while secondary wall thickness lasted 15 d. Enlargement in latewood cells averaged 7 d and secondary wall deposition occurred over an average of 27 d.
    Cell size across the tree ring is closely connected to the temporal dynamics of cell formation. Similar relationships were observed among the five study sites, indicating shared xylem formation dynamics across the entire latitudinal distribution of the species.The duration of cell differentiation is a key factor involved in cell growth and wall thickening of xylem, thereby determining the spatial variation of cell traits across the tree ring.
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  • 文章类型: Journal Article
    Present-day global warming is occurring faster at higher elevations. Although there is much information regarding the divergent responses of tree growth to climate change, the altitudinal patterns of species-specific xylogenesis remains poorly understood. We investigated the xylogenesis of balsam fir (Abies balsamea Mill.) and black spruce (Picea mariana Mill. B.S.P.) at two elevations in Quebec (Canada). The number of enlarging and mature cells of the developing tree ring were counted on microcores collected weekly between 2011 and 2014. At the lower site, the growth pattern and duration of xylogenesis were similar between species. No difference in responses to temperature and solar radiation between species was observed. At the higher site, however, cell production was higher and lasted longer in balsam fir than black spruce. Furthermore, the xylem growth of balsam fir had a stronger response to temperature and solar radiation than black spruce. These findings demonstrate the contrasting strategies of wood formation of the two species, with black spruce being more conservative than balsam fir. Our study provides evidence that sympatric species can have species-specific growth dynamics and site-specific responses to the local environment. Predictions of tree growth under a changing environment require the incorporation of species-specific growth strategies.
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  • 文章类型: Journal Article
    OBJECTIVE: the aim of the study was to evaluate the efficacy of continuous positive airway pressure (CPAP) for the treatment of obstructive sleep apnea in the elderly.
    METHODS: a comprehensive search for qualified clinical trials was performed on April, 2016. Basic demographic information of enrolled subjects, study design, survival rate, cardiovascular events, quality of life scores, and neurocognitive data were extracted for analysis.
    RESULTS: A total of seven clinical trials were included in this meta-analysis, in which untreated elderly patients exhibited worse survival rate than those with CPAP (OR=2.22, 95% CI=1.64 to 3.01, P< 0.00001). Treated elderly patients exhibited less cardiovascular risk than those without CPAP (RR=0.49, 95% CI=0.36 to 0.66, P<0.00001) and a statistically significant improvement on all the domains of Quebec Sleepiness Questionnaire, supported by pooled weighted mean difference. Furthermore, CPAP treatment partially improved the cognitive functions.
    CONCLUSIONS: CPAP treatment achieves improvements in decreasing mortality and controlling cardiovascular events and exhibits few effects on neurocognitive function. Further large-scale, well-designed interventional investigation is needed.
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