Surveying the endomicrobiome and ectomicrobiome of bark beetles: The case of Dendroctonus simplex.

International audienceMany bark beetles belonging to the Dendroctonus genus carry bacterial and fungal microbiota, forming a symbiotic complex that helps the insect to colonize the subcortical environment of the host tree. However, the biodiversity of those bacteria at the surface of the cuticle or inside the body parts of bark beetles is not well established. The aim of this study was to characterize the bacterial microbiome associated with the eastern larch beetle, Dendroctonus simplex, using bacterial 16S rRNA gene pyrosequencing. The ecto- and endomicrobiome and the subcortical galleries were investigated. Several bacterial genera were identified, among which Pseudomonas, Serratia and Yersinia are associated with the surface of the beetle cuticle, and genera belonging to Enterobacteriaceae and Gammaproteobacteria with the interior of the insect body. The index of dissimilarity indicates that the bacterial microbiome associated with each environment constitutes exclusive groups. These results suggest the presence of distinct bacterial microbiota on the surface of the cuticle and the interior of D. simplex body. Additionally, the bacterial diversity identified in the galleries is substantially different from the ectomicrobiome, which could indicate a selection by the insect. This study reports for the first time the identification of the eastern larch beetle microbiome

Intakes of total, free, and naturally occurring sugars in the french-speaking adult population of the province of Québec, Canada : the PREDISE study

The objective of this study was to characterize the intakes of different types of sugars in an age- and sex-representative sample of French-speaking adults from five regions of the Province of Québec, Canada, enrolled in the cross-sectional PREDISE (PRÉDicteurs Individuels, Sociaux et Environnementaux) study (n = 1147, 18–65 years old; 50.2% women). Because only total sugar content of foods and beverages is available in the Canadian Nutrient File (CNF) 2015, the initial step of this study was thus to build a database of free and naturally occurring sugars content of each food item and recipe included in the R24W, which is an automated, self-administered, web-based, 24-h dietary recall validated to estimate nutrient intakes in French-speaking adults of the Province of Québec. Total sugars were manually differentiated into free and naturally occurring sugars using a systematic algorithm based on previously published systematic algorithms. The World Health Organization (WHO)’s free sugar definition was used to differentiate total sugars into free and naturally occurring sugars. Dietary intake estimates were assessed using three 24-h dietary recalls completed with the R24W. Mean total, free, and naturally occurring sugar intakes were 116.4 g (19.3% of daily energy intake (%E)), 72.5 g (11.7%E), and 44.0 g (7.5%E), respectively. Over half (57.3%) of the overall sample did not meet the WHO’s recommendation to consume less than 10%E from free sugars. Women had a higher %E from naturally occurring sugars than men and being younger was associated with a greater %E from free sugars. Sugar intakes among French-speaking adults from the Province of Québec were mainly in the form of free sugars, with the majority of the population exceeding the WHO recommendation regarding free sugar intake. This suggests that public health efforts towards reducing free sugar intake in this population are relevant and necessary, considering that overconsumption of free sugars negatively influences health outcomes

MagAO Imaging of Long-period Objects (MILO). II. A Puzzling White Dwarf around the Sun-like Star HD 11112

The version of record, Rodigas, T. J. et al, 'MagAO Imaging of long-period objects (MILO). II. A puzzling white dwarf around the sun-like star HD 11112', The Astrophysical Journal, 831:177, November 2016, is available online via doi: 10.3847/0004-637X/831/2/177 © 2016. The American Astronomical Society. All rights reserved.HD 11112 is an old, Sun-like star that has a long-term radial velocity (RV) trend indicative of a massive companion on a wide orbit. Here we present direct images of the source responsible for the trend using the Magellan Adaptive Optics system. We detect the object (HD 11112B) at a separation of 2\fasec 2 (100 AU) at multiple wavelengths spanning 0.6-4 \microns ~and show that it is most likely a gravitationally-bound cool white dwarf. Modeling its spectral energy distribution (SED) suggests that its mass is 0.9-1.1 \msun, which corresponds to very high-eccentricity, near edge-on orbits from Markov chain Monte Carlo analysis of the RV and imaging data together. The total age of the white dwarf is $>2\sigma$ discrepant with that of the primary star under most assumptions. The problem can be resolved if the white dwarf progenitor was initially a double white dwarf binary that then merged into the observed high-mass white dwarf. HD 11112B is a unique and intriguing benchmark object that can be used to calibrate atmospheric and evolutionary models of cool white dwarfs and should thus continue to be monitored by RV and direct imaging over the coming years.Peer reviewedFinal Published versio

Caractérisation de l’apport en sucres libres et naturellement présents dans la population adulte québécoise, et leur association avec des marqueurs de santé cardiométabolique

L’effet direct ou indirect de la consommation de sucres libres sur la santé cardiométabolique est un sujet controversé et complexe. Depuis quelques années, l’intérêt pour ce nutriment s’est accru. On distingue deux principaux types de sucres (sucres libres, en opposition aux sucres naturellement présents; faisant référence au fait qu’ils soient extraits ou non de leur matrice alimentaire d’origine), qui ne seraient pas associés de la même manière à des variables de santé. Comme il n’existe aucune méthode chimique permettant de distinguer les sucres libres des sucres naturellement présents, on ne retrouve généralement que les teneurs en sucres totaux sur les étiquettes de valeurs nutritives et dans les bases de données nutritionnelles. Une différenciation manuelle des sucres totaux doit donc être faite afin de caractériser l’apport en sucres libres et naturellement présents des populations et de le comparer aux recommandations nutritionnelles en vigueur. Nos travaux ont permis de caractériser ces apports dans la population adulte québécoise, pour la première fois. Une fois que les sucres libres et naturellement présents ont été différenciés, on a pu étudier les associations de la consommation de sucre selon le type (libre ou naturellement présent) et selon la source (liquide (boissons) ou solide (aliments)) avec des marqueurs de santé cardiométabolique. Nos travaux à ce sujet, bien qu’ils s’appuient sur des données observationnelles transversales et qu’on ne puisse donc pas tirer de relations de cause à effet, s’inscrivent dans une littérature émergente, relativement peu abondante, controversée et qui mérite qu’on s’y attarde avec nuances. Ce mémoire présente mes travaux portant sur le sucre, effectués durant mon projet de maîtrise, leur importance, ainsi que ce que leurs retombées suggèrent pour améliorer les stratégies de santé publique en lien avec la consommation de sucre, de façon plus générale, et de boissons sucrées, de façon plus précise.The direct or indirect effect of the consumption of free sugars on cardiometabolic health is a controversial and complex topic. In recent years, interest in this nutrient has increased. There are two main types of sugars (free sugars, as opposed to naturally occurring sugars; referring to whether or not they are extracted from their original food matrix), which appear not to be associated in the same way with health variables. Since there is no chemical method to distinguish free sugars from naturally occurring sugars, only the total sugar content is generally found on nutrition facts labels and in nutrient databases. Manual differentiation of total sugars must therefore be made in order to characterize the intake of free and naturally occurring sugars in populations and to compare it with current dietary recommendations. Our work has made it possible to characterize these intakes in the Quebec adult population for the first time. Once free and naturally occurring sugars were differentiated, we were able to study the associations of sugar consumption by type (free or naturally occurring) and by source (liquid (beverages) or solid (foods)) with cardiometabolic health markers. Our work, although based on cross-sectional observational data and from which we cannot therefore draw causal relationships, is part of an emerging literature that is relatively sparse, controversial, and deserves a nuanced approach. This master’s thesis presents the work I did on sugar during my master's project, its importance, as well as what its repercussions suggest for improving public health strategies about sugar consumption, more generally, and sugar-sweetened beverages, more specifically

Maintien de l’engagement paternel après une rupture conjugale : point de vue de pères vivant en contexte de pauvreté

La séparation conjugale et la pauvreté menacent doublement le maintien de l’engagement paternel. À partir du discours de pères séparés vivant en contexte de pauvreté et qui se considèrent comme engagés envers leur enfant, l’étude vise à comprendre comment ces pères maintiennent leur engagement envers leur enfant dans l’adversité. Les participants rapportent diverses stratégies pour rester pères dans un contexte où s’additionnent contraintes et pressions imputables tant à la rupture qu’à la pauvreté. De l’analyse se dégagent des éléments qui semblent avoir encouragé la continuité de leur engagement paternel. Une meilleure compréhension des enjeux reliés à ce phénomène contribuera sans doute à alimenter la réflexion et la pratique des intervenants et ainsi à réduire la double pauvreté des enfants qui, en plus d’être économiquement défavorisés, se retrouvent encore trop souvent, après la rupture, privés de leur père.Separation from bed and board, and poverty constitute a dual threat to the maintenance of paternal commitment. Taking as a starting point the views of separated fathers living below the poverty line and who feel committed to their children, this study attempts to understand how fathers maintain this commitment to their child in the face of adversity. The participants describe various strategies that allow them to maintain their paternal role in a context where they have to deal with a combination of constraints and pressures resulting partly from the break-up, partly from poverty. This analysis brings out elements that appear to have encouraged them to pursue their paternal commitment. A greater understanding of what is at stake in such situations should help those involved to better reflect and act in such a way as to diminish the twin impoverishments that afflict their children : economic disadvantage and loss of a father, both of which are too often the consequences of marital breakdown

Maintien de l’engagement paternel après une rupture conjugale : point de vue de pères vivant en contexte de pauvreté

La séparation conjugale et la pauvreté menacent doublement le maintien de l’engagement paternel. À partir du discours de pères séparés vivant en contexte de pauvreté et qui se considèrent comme engagés envers leur enfant, l’étude vise à comprendre comment ces pères maintiennent leur engagement envers leur enfant dans l’adversité. Les participants rapportent diverses stratégies pour rester pères dans un contexte où s’additionnent contraintes et pressions imputables tant à la rupture qu’à la pauvreté. De l’analyse se dégagent des éléments qui semblent avoir encouragé la continuité de leur engagement paternel. Une meilleure compréhension des enjeux reliés à ce phénomène contribuera sans doute à alimenter la réflexion et la pratique des intervenants et ainsi à réduire la double pauvreté des enfants qui, en plus d’être économiquement défavorisés, se retrouvent encore trop souvent, après la rupture, privés de leur père.Separation from bed and board, and poverty constitute a dual threat to the maintenance of paternal commitment. Taking as a starting point the views of separated fathers living below the poverty line and who feel committed to their children, this study attempts to understand how fathers maintain this commitment to their child in the face of adversity. The participants describe various strategies that allow them to maintain their paternal role in a context where they have to deal with a combination of constraints and pressures resulting partly from the break-up, partly from poverty. This analysis brings out elements that appear to have encouraged them to pursue their paternal commitment. A greater understanding of what is at stake in such situations should help those involved to better reflect and act in such a way as to diminish the twin impoverishments that afflict their children: economic disadvantage and loss of a father, both of which are too often the consequences of marital breakdown