Sociodemographic patterning of dietary profiles among Inuit youth and adults in Nunavik, Canada: a cross-sectional study

Objectives Country (traditional) foods are integral to Inuit culture, but market food consumption is increasing. The Qanuilirpitaa? 2017 Nunavik Health Survey (Q2017) reported similar country food consumption frequency compared to that in 2004; however, examining food items individually does not account for diet patterns, food accessibility, and correlations between food items. Our objective was to identify underlying dietary profiles and compare them across sex, age, ecological region, and food insecurity markers, given the links among diet, health, and sociocultural determinants. Methods Food frequency and sociodemographic data were derived from the Q2017 survey (N = 1176). Latent profile analysis identified dietary profiles using variables for the relative frequencies of country and market food consumption first, followed by an analysis with those for country food variables only. Multinomial logistic regression examined the associations among dietary profiles, sociodemographic factors, and food insecurity markers (to disassociate between food preferences and food access). Results Four overall dietary profiles and four country food dietary profiles were identified characterized by the relative frequency of country and market food in the diet. The patterns were stable across several sensitivity analyses and in line with our Inuit partners’ local knowledge. For the overall profiles, women and adults aged 30–49 years were more likely to have a market food–dominant profile, whereas men and individuals aged 16–29 and 50+ years more often consumed a country food–dominant profile. In the country food profiles, Inuit aged 16–29 years were more likely to have a moderate country food profile whereas Inuit aged 50+ were more likely to have a high country food–consumption profile. A low country and market food–consumption profile was linked to higher prevalence of food insecurity markers. Conclusion We were able to identify distinct dietary profiles with strong social patterning. The profiles elucidated in this study are aligned with the impact of colonial influence on diet and subsequent country food promotion programs for Inuit youth. These profiles will be used for further study of nutritional status, contaminant exposure, and health to provide context for future public health programs.Objectifs Les aliments traditionnels font partie intégrante de la culture inuite, mais la consommation d’aliments du marché est en augmentation. L’enquête de santé des Inuit Qanuilirpitaa? réalisée en 2017 (Q2017) a mis en évidence que la fréquence de consommation d’aliments traditionnels était similaire à celle rapportée en 2004. Or, les fréquences de consommation des aliments pris individuellement ne tiennent pas compte des habitudes alimentaires, de l’accessibilité des aliments et des corrélations entre les aliments consommés. Notre objectif était d’identifier les profils alimentaires sous-jacents et de les comparer selon le sexe, l’âge, la région écologique et les marqueurs d’insécurité alimentaire, étant donné le lien entre l’alimentation, la santé et les déterminants socioculturels. Méthodes Les données sur les fréquences alimentaires et sociodémographiques sont issues de l’enquête Q2017 (N=1176). L’analyse des profils latents a permis d’identifier des profils alimentaires en utilisant les variables pour les fréquences relatives de la consommation d’aliments traditionnels et du marché et uniquement celles pour les aliments traditionnels. Des régressions logistiques multinomiales ont été utilisées pour examiner les associations entre les profils alimentaires, les facteurs sociodémographiques et les marqueurs d’insécurité alimentaire (pour dissocier les préférences alimentaires de l’accès aux aliments). Résultats Quatre profils alimentaires globaux et quatre profils alimentaires spécifiques à la consommation d’aliments traditionnels ont été identifiés en fonction de la fréquence relative des aliments traditionnels et des aliments du marché dans l’alimentation. Les profils étaient en accord avec les connaissances locales de nos partenaires Inuit. Pour les profils alimentaires globaux, les femmes et les adultes âgés de 30 à 49 ans étaient plus susceptibles d’avoir un profil dominé par les aliments du marché, tandis que les hommes et les personnes âgées de 16 à 29 ans et celles de 50 ans et plus avaient plus fréquemment un profil dominé par les aliments traditionnels. En ce qui concerne les profils de consommation d’aliments traditionnels, les Inuit âgés de 16 à 29 ans étaient plus susceptibles d’avoir un profil modéré de consommation d’aliments traditionnels, tandis que les Inuit âgés de 50 ans et plus étaient plus susceptibles d’avoir un profil élevé de consommation d’aliments traditionnels. Un profil bas de consommation d’aliments traditionnels et de marché était associé à une prévalence plus élevée de marqueurs d’insécurité alimentaire. Conclusion Nous avons identifié différents profils alimentaires et ces derniers étaient associés à des caractéristiques socio-démographiques distinctes. Les profils alimentaires mis en lumière dans cette étude concordent avec l’impact du colonialisme sur l’alimentation au Nunavik et aux programmes subséquents de promotion des aliments traditionnels auprès des jeunes Inuit. Ces profils seront utilisés pour une étude plus approfondie du statut nutritionnel, de l’exposition aux contaminants et des issues de santé afin d’identifier des pistes de solutions pour les futurs programmes de santé publique

Seasonal variations in exposure to methylmercury and its dietary sources among pregnant Inuit women in Nunavik, Canada

Among populations living in close connection with the sea, rivers and lakes for subsistence, diet varies according to local monthly wildlife species availability and food preferences. This may lead to variations in methylmercury (MeHg) exposure over a year, although no biomonitoring studies have documented this issue in Circumpolar populations, the most exposed to international Hg emissions. Our aim was to characterize seasonal variations in MeHg exposure among pregnant Inuit women from Nunavik and to identify country foods responsible for these variations. Between October 2016 and March 2017, 97 participants were recruited. Blood mercury (Hg) was tested and hair Hg was measured by centimeter as a surrogate for monthly MeHg exposure over the past year. Latent class growth analysis was conducted to identify groups of pregnant women with similar hair Hg monthly trajectories. Country foods consumption was documented by season. Seasonal daily intakes of MeHg were estimated based on concentrations in country foods. Retrospective monthly hair Hg analyses revealed that MeHg exposure was lowest in winter, and highest in summer and early fall months. Three latent classes (groups) of pregnant women with similar trajectories of monthly hair Hg variations were identified: high (n = 20, 21%), moderate (n = 38, 41%) and low variation (n = 35, 38%). Beluga meat was the country food contributing to most of daily MeHg intake, primarily during summer and fall, and was the only one associated with the odds of being classified into moderate and high variation groups (OR 95% CI: 1.19 [1.01–1.39] and 1.25 [1.04–1.50]). These findings underscore the importance of monthly variations in exposure to MeHg due to the seasonality of local foods consumed and responsible for elevated MeHg exposure. Further studies critically need to understand local diet fluctuations over a year to adequately assess MeHg exposure, adopt timely preventive interventions and evaluate the effectiveness of the Minamata Convention

PARP3 affects the relative contribution of homologous recombination and nonhomologous end-joining pathways

The repair of toxic double-strand breaks (DSB) is critical for the maintenance of genome integrity. The major mechanisms that cope with DSB are: homologous recombination (HR) and classical or alternative nonhomologous end joining (C-NHEJ versus A-EJ). Because these pathways compete for the repair of DSB, the choice of the appropriate repair pathway is pivotal. Among the mechanisms that influence this choice, deoxyribonucleic acid (DNA) end resection plays a critical role by driving cells to HR, while accurate C-NHEJ is suppressed. Furthermore, end resection promotes error-prone A-EJ. Increasing evidence define Poly(ADP-ribose) polymerase 3 (PARP3, also known as ARTD3) as an important player in cellular response to DSB. In this work, we reveal a specific feature of PARP3 that together with Ku80 limits DNA end resection and thereby helps in making the choice between HR and NHEJ pathways. PARP3 interacts with and PARylates Ku70/Ku80. The depletion of PARP3 impairs the recruitment of YFP-Ku80 to laser-induced DNA damage sites and induces an imbalance between BRCA1 and 53BP1. Both events result in compromised accurate C-NHEJ and a concomitant increase in DNA end resection. Nevertheless, HR is significantly reduced upon PARP3 silencing while the enhanced end resection causes mutagenic deletions during A-EJ. As a result, the absence of PARP3 confers hypersensitivity to anti-tumoral drugs generating DSB

Contributions and perspectives of Indigenous Peoples to the study of mercury in the Arctic

Arctic Indigenous Peoples are among themost exposed humanswhen it comes to foodbornemercury (Hg). In response, Hgmonitoring and research have been on-going in the circumpolar Arctic since about 1991; this work has beenmainly possible through the involvement of Arctic Indigenous Peoples. The present overview was initially conducted in the context of a broader assessment of Hg research organized by the Arctic Monitoring and Assessment Programme. This article provides examples of Indigenous Peoples' contributions to Hg monitoring and research in the Arctic, and discusses approaches that could be used, and improved upon, when carrying out future activities. Over 40 mercury projects conducted with/by Indigenous Peoples are identified for different circumpolar regions including the U.S., Canada, Greenland, Sweden, Finland, and Russia as well as instances where Indigenous Knowledge contributed to the understanding of Hg contamination in the Arctic. Perspectives and visions of future Hg research as well as recommendations are presented. The establishment of collaborative processes and partnership/co-production approaches with scientists and Indigenous Peoples, using good communication practices and transparency in research activities, are key to the success of research and monitoring activities in the Arctic. Sustainable funding for community-driven monitoring and research programs in Arctic countries would be beneficial and assist in developing more research/monitoring capacity and would promote a more holistic approach to understanding Hg in the Arctic. These activities should be well connected to circumpolar/international initiatives to ensure broader availability of the information and uptake in policy development

Consequences of various landscape-scale ecosystem management strategies and fire cycles on age-class structure and harvest in boreal forests

At the landscape scale, one of the key indicators of sustainable forest management is the age-class distribution of stands, since it provides a coarse synopsis of habitat potential, structural complexity, and stand volume, and it is directly modified by timber extraction and wildfire. To explore the consequences of several landscape-scale boreal forest management strategies on age-class structure in the Mauricie region of Quebec, we used spatially explicit simulation modelling. Our study investigated three different harvesting strategies (the one currently practiced and two different strategies to maintain late seral stands) and interactions between fire and harvesting on stand age-class distribution. We found that the legacy of initial forested age structure and its spatial configuration can pose short- (<50 years) to medium-term (150-300 years) challenges to balancing wood supply and ecological objectives. Also, ongoing disturbance by fire, even at relatively long cycles in relation to historic levels, can further constrain the achievement of both timber and biodiversity goals. For example, when fire was combined with management, harvest shortfalls occurred in all scenarios with a fire cycle of 100 years and most scenarios with a fire cycle of 150 years. Even a fire cycle of 500 years led to a reduction in older forest when its maintenance was not a primary constraint. Our results highlight the need to consider the broad-scale effects of natural disturbance when developing ecosystem management policies and the importance of prioritizing objectives when planning for multiple resource use

Contributions and perspectives of Indigenous Peoples to the study of mercury in the Arctic

Arctic Indigenous Peoples are among the most exposed humans when it comes to foodborne mercury (Hg). In response, Hg monitoring and research have been on-going in the circumpolar Arctic since about 1991; this work has been mainly possible through the involvement of Arctic Indigenous Peoples. The present overview was initially conducted in the context of a broader assessment of Hg research organized by the Arctic Monitoring and Assessment Programme. This article provides examples of Indigenous Peoples' contributions to Hg monitoring and research in the Arctic, and discusses approaches that could be used, and improved upon, when carrying out future activities. Over 40 mercury projects conducted with/by Indigenous Peoples are identified for different circumpolar regions including the U.S., Canada, Greenland, Sweden, Finland, and Russia as well as instances where Indigenous Knowledge contributed to the understanding of Hg contamination in the Arctic. Perspectives and visions of future Hg research as well as recommendations are presented. The establishment of collaborative processes and partnership/co-production approaches with scientists and Indigenous Peoples, using good communication practices and transparency in research activities, are key to the success of research and monitoring activities in the Arctic. Sustainable funding for community-driven monitoring and research programs in Arctic countries would be beneficial and assist in developing more research/ monitoring capacity and would promote a more holistic approach to understanding Hg in the Arctic. These activities should be well connected to circumpolar/international initiatives to ensure broader availability of the information and uptake in policy development

Integrin/Fak/Src-mediated regulation of cell survival and anoikis in human intestinal epithelial crypt cells: selective engagement and roles of PI3-K isoform complexes

In human intestinal epithelial crypt (HIEC) cells, the PI3-K/Akt-1 pathway is crucial for the promotion of cell survival and suppression of anoikis. Class I PI3-K consists of a complex formed by a catalytic (C) and regulatory (R) subunit. Three R (p85α, β, and p55γ) and four C (p110α, β, γ and δ) isoforms are known. Herein, we analyzed the expression of PI3-K isoforms in HIEC cells and determined their roles in cell survival, as well as in the β1 integrin/Fak/Src-mediated suppression of anoikis. We report that: (1) the predominant PI3-K complexes expressed by HIEC cells are p110α/p85β and p110α/p55γ; (2) the inhibition and/or siRNA-mediated expression silencing of p110α, but not that of p110β, γ or δ, results in Akt-1 down-activation and consequent apoptosis; (3) the expression silencing of p85β or p55γ, but not that of p85α, likewise induces Akt-1 down-activation and apoptosis; however, the impact of a loss of p55γ on both Akt-1 activation and cell survival is significantly greater than that from the loss of p85β; and (4) both the p110α/p85β and p110α/p55γ complexes are engaged by β1 integrin/Fak/Src signaling; however, the engagement of p110α/p85β is primarily Src-dependent, whereas that of p110α/p55γ is primarily Fak-dependent (but Src-independent). Hence, HIEC cells selectively express PI3-K isoform complexes, translating into distinct roles in Akt-1 activation and cell survival, as well as in a selective engagement by Fak and/or Src within the context of β1 integrin/Fak/Src-mediated suppression of anoikis

Simultaneous isolation of keratinocytes and fibroblasts from a human cutaneous biopsy for the production of autologous reconstructed skin

The key step In the reconstruction of skin by the self-assembly approach is to use fibroblasts capable of secreting a mature extracellular matrix and keratinocytes that can associate with one another to form a stratified, differentiated epidermis. To determine the most efficient way to extract both cell types from a single cutaneous biopsy, five different enzymatic combinations were tested. The yield, viability and morphology of the recuperated cells were compared. The length and temperature of the enzymatic treatments influenced the number and the type of cells recuperated. The cells were then cultured in appropriate media in monolayers and reconstructed skin were produced using the self-assembly approach. No difference was observed between the different strains of cells.La réussite de la technique d'auto-assemblage pour la reconstruction de la peau dépend de la capacité des fibroblastes à sécréter une matrice extracellulaire complexe ainsi que celle des kératinocytes à s'associer pour former un épiderme stratifié et différencié. Pour déterminer la manière la plus efficace d'extraire ces deux types cellulaires d'une seule biopsie cutané, cinq combinaisons d'enzymes ont été comparées. La durée et la température des traitements enzymatiques ont influencé le nombre de cellule récupérés. Les cellules ont d'abord été cultivées en monouche, puis peaux reconstruites par la méthode d'auto-assemblage ont été produites. Aucune différence n'a été observée entre les différentes Iignées