SERG Final report: Ecosystemic impacts of forest tent caterpillar outbreaks

The forest tent caterpillar (Malacosoma disstria) is a significant defoliator of hardwoods throughout Canada. Historically, infestations usually collapsed after one or two years of defoliation, but longer and more severe outbreaks have been observed in recent years, leading to mortality of both sugar maple and trembling aspen, and making the forest tent caterpillar another pest whose impacts are increasing under a changing climate. This project examines how forest tent caterpillar outbreaks influence soil ecosystems, in both temperate deciduous and mixed boreal forests. We will assess inputs to soil ecosystems associated with forest tent caterpillar outbreaks and determine impacts on soil arthropod communities and tree regeneration. We also examine the different sources of mortality of the forest tent caterpillar colonies during and after the outbreak. It will thus provide empirical data to assess effects of forest tent caterpillar outbreaks on forest ecosystems and successional processes as well as population dynamics throughout the outbreaking cycle. Results suggest that defoliation favours the growth of non-host saplings. They also suggest that sources of mortality change during the different parts of the outbreak. Results will also contribute to the development of novel silvicultural approaches taking into account the effects of forest tent caterpillar outbreaks on forest regeneration and the need to keep process promoting regulation of forest tent caterpillar populations. La livrée des forêts (Malacosoma disstria) est un défoliateur important des forêts feuillues du Canada. Dans le passé, les épidémies s’effondraient généralement après une ou deux années de défoliation sans causer de dommages significatifs à la forêt, mais l’observation récente d’épidémies plus longues et plus sévères, suivies de mortalité des tiges de peuplier faux-tremble et d’érable à sucre, suggèrent que les impacts de la livrée des forêts, comme de plusieurs autres insectes ravageurs, augmentent en raison des changements climatiques. Ce projet examine les effets d’une épidémie de livrée des forêts sur l’écosystème du sol dans deux écosystèmes forestiers: la forêt feuillue et la forêt boréale mixte. Nous examinerons les apports en nutriments au sol associés aux épidémies de livrée et évaluerons les effets sur la communauté d’arthropodes du sol et sur la régénération des arbres. Nous avons aussi examiné les sources de mortalité des colonies de livrée des forêts durant et après l’épidémie. Les résultats fourniront des données empiriques pour évaluer les impacts des épidémies de livrée sur les écosystèmes forestiers et les processus de succession écologiques ainsi que les dynamiques de populations à travers les cycles épidémiques. Les résultats suggèrent que la défoliation peut bénéficier la croissance des jeunes arbres non-hôtes. Ils suggèrent aussi que les sources de mortalité diffèrent lors des différentes parties du cycles épidémiques. Les résultats contribueront aussi au développement d’approches sylvicoles qui prennent en considération le rôle de la livrée dans la régénération des forêts

The one year fate of iron oxide coated gold nanoparticles in mice

Safe implementation of nanotechnology and nanomedicine requires an in-depth understanding of the life cycle of nanoparticles in the body. Here, we investigate the long-term fate of gold/iron oxide heterostructures after intravenous injection in mice. We show these heterostructures degrade in vivo and that the magnetic and optical properties change during the degradation process. These particles eventually eliminate from the body. The comparison of two different coating shells for heterostructures, amphiphilic polymer or polyethylene glycol, reveals the long lasting impact of initial surface properties on the nanocrystal degradability and on the kinetics of elimination of magnetic iron and gold from liver and spleen. Modulation of nanoparticles reactivity to the biological environment by the choice of materials and surface functionalization may provide new directions in the design of multifunctional nanomedicines with predictable fate

Compression irréversible par ondelettes en radiologie thoracique numérique : Evaluation qualitative sur des structures anatomiques et pathologiques

La compression d'images représente une alternative de faible coût à l'augmentation systématique de la capacité de stockage des systèmes d'archivage et des lignes de transmission (PACS). Afin d'étudier les effets de la compression irréversible par ondelettes (base de la norme JPEG2000) sur des radiographies thoraciques d'emblée numériques (Thoravision®), nous avons défini un protocole complet d'évaluation. Les taux de compression de 20:1, 40:1, 60:1 ont été évalués en double aveugle par 3 radiologues dans des conditions standardisées sur des structures anatomiques (suivant 11 critères portant sur les détails, les contours et les artéfacts sur une population de 30 sujets sains) et pathologiques (pneumothorax et syndromes interstitiels). Des courbes ROC ont été réalisées à partir de deux populations de 20 patients. Notre étude détermine un taux de compression acceptable à 20:1 pour les radiographies normales et 60:1 pour les images pathologiques. L'interprétation rigoureuse d'une radiographie thoracique nécessitant la conservation des structures anatomiques, le taux de 20:1 apparaît être la limite acceptable en pratique clinique. Notre protocole d'évaluation suggère par ailleurs qu'une évaluation qualitative d'une compression par ondelettes de radiographie thoracique peut être réalisée uniquement sur des critères anatomiques portant sur la vascularisation fine du poumon où la dégradation est prédominante

RODIN project, Topology Optimization 2.0?

RODIN project is an attempt to propose a new kind of topology optimization tools. It has been motivated by the combination of two events: (1) the industrials demands for getting past serious limits identified in the available tools, (2) the advent of a new mathematical approach in the mid 2000's presenting very interesting properties. This project has been launched in July 2012 and is supported by French public funding. It is a collaborative project that gathers ten partners (ranging from academics to software editors and industrials end-users) and firmly aims at overcoming technical and scientific locks in the area of topology optimization. RODIN is therefore an ambitious and risky project that will possibly mark the birth of a new numerical tool

Impact of model resolution on tropical cyclone simulation using the HighResMIP–PRIMAVERA multimodel Ensemble

A multimodel, multiresolution set of simulations over the period 1950–2014 using a common forcing protocol from CMIP6 HighResMIP have been completed by six modeling groups. Analysis of tropical cyclone performance using two different tracking algorithms suggests that enhanced resolution toward 25 km typically leads to more frequent and stronger tropical cyclones, together with improvements in spatial distribution and storm structure. Both of these factors reduce typical GCM biases seen at lower resolution. Using single ensemble members of each model, there is little evidence of systematic improvement in interannual variability in either storm frequency or accumulated cyclone energy as compared with observations when resolution is increased. Changes in the relationships between large-scale drivers of climate variability and tropical cyclone variability in the Atlantic Ocean are also not robust to model resolution. However, using a larger ensemble of simulations (of up to 14 members) with one model at different resolutions does show evidence of increased skill at higher resolution. The ensemble mean correlation of Atlantic interannual tropical cyclone variability increases from ~0.5 to ~0.65 when resolution increases from 250 to 100 km. In the northwestern Pacific Ocean the skill keeps increasing with 50-km resolution to 0.7. These calculations also suggest that more than six members are required to adequately distinguish the impact of resolution within the forced signal from the weather noise

Altered Neurocircuitry in the Dopamine Transporter Knockout Mouse Brain

The plasma membrane transporters for the monoamine neurotransmitters dopamine, serotonin, and norepinephrine modulate the dynamics of these monoamine neurotransmitters. Thus, activity of these transporters has significant consequences for monoamine activity throughout the brain and for a number of neurological and psychiatric disorders. Gene knockout (KO) mice that reduce or eliminate expression of each of these monoamine transporters have provided a wealth of new information about the function of these proteins at molecular, physiological and behavioral levels. In the present work we use the unique properties of magnetic resonance imaging (MRI) to probe the effects of altered dopaminergic dynamics on meso-scale neuronal circuitry and overall brain morphology, since changes at these levels of organization might help to account for some of the extensive pharmacological and behavioral differences observed in dopamine transporter (DAT) KO mice. Despite the smaller size of these animals, voxel-wise statistical comparison of high resolution structural MR images indicated little morphological change as a consequence of DAT KO. Likewise, proton magnetic resonance spectra recorded in the striatum indicated no significant changes in detectable metabolite concentrations between DAT KO and wild-type (WT) mice. In contrast, alterations in the circuitry from the prefrontal cortex to the mesocortical limbic system, an important brain component intimately tied to function of mesolimbic/mesocortical dopamine reward pathways, were revealed by manganese-enhanced MRI (MEMRI). Analysis of co-registered MEMRI images taken over the 26 hours after introduction of Mn^(2+) into the prefrontal cortex indicated that DAT KO mice have a truncated Mn^(2+) distribution within this circuitry with little accumulation beyond the thalamus or contralateral to the injection site. By contrast, WT littermates exhibit Mn^(2+) transport into more posterior midbrain nuclei and contralateral mesolimbic structures at 26 hr post-injection. Thus, DAT KO mice appear, at this level of anatomic resolution, to have preserved cortico-striatal-thalamic connectivity but diminished robustness of reward-modulating circuitry distal to the thalamus. This is in contradistinction to the state of this circuitry in serotonin transporter KO mice where we observed more robust connectivity in more posterior brain regions using methods identical to those employed here

Patient selection for laparoscopic excision of adrenal metastases: a multicenter cohort study

International audienceIntroduction The use of laparoscopy for the excision of adrenal metastasis remains controversial. We aimed to report oncological and perioperative outcomes of laparoscopic excision of adrenal metastases and to seek for predictive factors of unfavourable oncological outcomes. Methods A retrospective chart review was conducted and all consecutive patients who underwent laparoscopic adrenalectomy (LA) in the setting of metastatic cancer in two academic urology departments from November 2006 through January 2014 were included. Primary tumors were categorized as pulmonary, renal or “other primary” tumors to allow statistical comparison. Unfavourable surgical outcomes were defined as the occurrence of either postoperative complications and/or positive surgical margins. Results Forty-three patients who underwent a total of 45 LA were included for analysis. There were 8 complications (17.8%). Positive surgical margins were found in 12 specimens (26.7%). After a median follow-up of 37 months, estimated overall survival rates were 89.5% and 51.5% at 1 year and 5 years, respectively. In multivariable analysis the only predictor of unfavourable surgical outcomes was a tumor size > 5 cm (OR= 20.5; p=0.001). In multivariate analysis the pulmonary (OR=0.3; p=0.008) or “other” (OR= 0.1; p=0.0006) origin of the primary tumor was the only prognostic factor of shorter cancer specific survival. Conclusion Laparoscopic resection of adrenal metastasis can be safely performed in most patients but is associated with an increased risk of positive surgical margins and postoperative complications in larger tumors (>5 cm). Adrenalectomy provides better oncological outcomes in metastases from renal cell carcinoma compared to other primary tumors

Coxiella burnetii, the Agent of Q Fever, Replicates within Trophoblasts and Induces a Unique Transcriptional Response

Q fever is a zoonosis caused by Coxiella burnetii, an obligate intracellular bacterium typically found in myeloid cells. The infection is a source of severe obstetrical complications in humans and cattle and can undergo chronic evolution in a minority of pregnant women. Because C. burnetii is found in the placentas of aborted fetuses, we investigated the possibility that it could infect trophoblasts. Here, we show that C. burnetii infected and replicated in BeWo trophoblasts within phagolysosomes. Using pangenomic microarrays, we found that C. burnetii induced a specific transcriptomic program. This program was associated with the modulation of inflammatory responses that were shared with inflammatory agonists, such as TNF, and more specific responses involving genes related to pregnancy development, including EGR-1 and NDGR1. In addition, C. burnetii stimulated gene networks organized around the IL-6 and IL-13 pathways, which both modulate STAT3. Taken together, these results revealed that trophoblasts represent a protective niche for C. burnetii. The activation program induced by C. burnetii in trophoblasts may allow bacterial replication but seems unable to interfere with the development of normal pregnancy. Such pathophysiologocal processes should require the activation of immune placental cells associated with trophoblasts

Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb−1 of s√=7TeV proton-proton collisions

Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb−1 of pp collision data at s√=7TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from ≥6 to ≥9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m 0, gluino masses smaller than 840 GeV are excluded at the 95% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV

Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal