37 research outputs found
Favoriser par l'art l'adaptation et l'intégration des jeunes issus de l'immigration : étude de quelques projets dans les organismes communautaires et dans le milieu scolaire montréalais
Cette recherche s'intĂ©resse Ă l'utilisation de l'art dans des organismes communautaires et dans le milieu scolaire montrĂ©alais auprĂšs des jeunes issus de l'immigration afin de favoriser leur adaptation et leur intĂ©gration. Ces derniers reprĂ©sentent une clientĂšle aux origines ethniques et aux besoins de plus en plus diversifiĂ©s. Encourager leur intĂ©gration Ă la sociĂ©tĂ© quĂ©bĂ©coise reprĂ©sente donc une tĂąche complexe qui nĂ©cessite des actions concertĂ©es dans toutes les sphĂšres de la sociĂ©tĂ©. La problĂ©matique de recherche s'articule autour de trois lacunes dans l'aide qui est actuellement apportĂ©e aux jeunes issus de l'immigration: Tout d'abord, un manque de ressources favorisant leur adaptation et leur intĂ©gration est observĂ©. DeuxiĂšmement, un manque de connaissances sur le potentiel de l'art afin de favoriser leur adaptation et leur intĂ©gration a Ă©tĂ© identifiĂ©. TroisiĂšmement, la prise en compte de la diversitĂ© ethnoculturelle des classes reprĂ©sente une difficultĂ© pour les enseignants en arts qui sont peu prĂ©parĂ©s Ă recevoir ces Ă©lĂšves. Les conclusions tirĂ©es de cette Ă©tude exploratoire dĂ©montrent que l'art peut ĂȘtre utilisĂ© avec succĂšs pour favoriser l'adaptation et l'intĂ©gration des jeunes issus de l'immigration, tant dans les ressources communautaires que dans le milieu scolaire. Le savoir-ĂȘtre des intervenants impliquĂ©s auprĂšs de ces jeunes semble aussi exercer un rĂŽle dĂ©terminant dans l'atteinte des objectifs souhaitĂ©s. Par exemple, lorsque les intervenants peuvent reprĂ©senter des modĂšles Ă qui s'identifier, lorsqu'ils sont engagĂ©s dans leur travail et qu'ils dĂ©veloppent des liens significatifs avec les jeunes, ceux-ci semblent rĂ©agir favorablement aux projets artistiques mis en place pour les aider dans leur cheminement. L'Ă©tablissement de ponts entre les jeunes, leur Ă©cole, leur famille et les services communautaires dans leur milieu de vie, parfois difficile Ă instaurer, semble aussi ĂȘtre trĂšs bĂ©nĂ©fique. Enfin, les professeurs qui enseignent dans des classes multiethniques devraient dĂ©velopper des projets significatifs pour les jeunes en tenant compte de leur culture d'origine, de leurs intĂ©rĂȘts et de leurs goĂ»ts. De plus, ils devraient favoriser un espace de crĂ©ation dans lequel les jeunes peuvent s'exprimer sur leur rĂ©alitĂ©. ______________________________________________________________________________ MOTS-CLĂS DE LâAUTEUR : Jeunes, Immigration, IntĂ©gration, Art
Grappling extremes: Molecular methods combined with cultivation reveal the composition and biology of space-relevant microbial communities
Extreme Biotope sind durch eine Vielzahl von physischen und chemischen Stressvariablen gekennzeichnet und bieten eine hervorragende Möglichkeit die Grenzen des Lebens zu verstehen â auch auĂerhalb der Erde z.B. auf der International Raumstation (ISS) oder auf dem Mars. Einige terrestrische, extreme LebensrĂ€ume Ă€hneln stark ausgewĂ€hlten Bedingungen auf dem Mars und lassen daher RĂŒckschlĂŒsse auf dessen potenzieller Bewohnbarkeit zu. Ein wesentlicher Faktor ist der Mangel an Sauerstoff auf dem Mars. Allerdings erweisen sich die Probennahme und mikrobielle Kultivierung aus sauerstoffarmen Umgebungen als sehr herausfordernd und werden nicht sehr oft praktiziert. Es benötigt besonders die Betrachtung solcher sauerstoffarmen Umgebungen und deren assoziierten Mikroorganismen, um einschĂ€tzen zu können, ob extraterrestrisches ausgestorbenes und/oder noch bestehendes Leben auf dem Mars existieren könnte. Bemannte Langzeitzeitmissionen zum Mars bedĂŒrfen zudem sowohl Wissen ĂŒber die mikrobielle DiversitĂ€t in Raumfahrtzeugen als auch ĂŒber deren AnpassungsfĂ€higkeit und Stress-Toleranzen. Nur dadurch kann ein sicheres Arbeitsklima sichergestellt werden. Die vorliegende Arbeit umfasst eine tiefreichende Untersuchung extremer Biotope mit Hilfe von Kultivierungsmethoden und molekularen Methoden und eine detaillierte Analyse einiger ausgewĂ€hlter mikrobiellen Bewohner.
Eines dieser extremen Biotope umfasst das kontrollierte Innenleben ISS. FrĂŒhere Studien detektierten bereits eine hohe Abundanz an Mensch-assoziierte Bakterien, allerdings blieb der Nachweis von Archaeen erfolglos. Archaeen sind allgegenwĂ€rtig auf der Erde und werden zahlreich in ReinrĂ€umen detektiert, in welchen die Raumschiff Hardware assembliert wird. Im Rahmen dieser Arbeit wurden 8-12 Jahre alte Staubproben auf deren mikrobielle DiversitĂ€t untersucht. Molekulare Analysen bestĂ€tigten ein mit dem Mensch assoziiertes Bakteriom. Zudem konnten zum ersten Mal auch archaelle Signaturen nachgewiesen werden. Kultivierte, bakterielle Einzelisolate ermöglichten es, Stress-resistente Experimente durchzufĂŒhren. Neben der Austrocknungsresistenz, zeigte eine Vielzahl von Isolaten eine hohe Resistenz gegen zahlreiche Antibiotika. Diese Ergebnisse erweitern unser Wissen ĂŒber die archaelle und bakterielle DiversitĂ€t und deren Adaptionen im Weltraum.
Terrestrische, Mars-Ă€hnliche Systeme ermöglichen es, Modellorganismen zu finden, welche potenziell auf dem Mars gelebt haben und/oder immer noch dort leben könnten. Zahlreiche Studien beschĂ€ftigten sich mit deren Untersuchung, allerdings fehlte bisher ein profundes Wissen ĂŒber sauerstoffarme Systeme. Im Rahmen des MASE Projektes (Mars Analogues for Space Exploration) wurden gezielt sauerstoffarme Biotope auf deren mikrobielle DiversitĂ€t untersucht. Einige dieser Biotope zeigen eine hohe Ăhnlichkeit zu Marsbedingungen in der Vergangenheit (vor ca. ~4 Milliarden Jahren), wĂ€hrend ein Biotop den Bedingungen auf dem heutigem Mars reflektiert. Auch hier konnten mit Hilfe eines umfassenden Kultivierungsansatzes zahlreiche Anaerobier erhalten werden, die als astrobiologische Modelle dienen. Molekulare Methoden prognostizierten eine auĂerordentliche AdaptionsfĂ€higkeit und hohe DiversitĂ€t in den untersuchten LebensrĂ€umen. Alle untersuchten, dem frĂŒhem Mars entsprechenden LebensrĂ€ume, so unterschiedlich sie auch sind, zeigten einen gemeinsamen taxonomischen Kern, welcher sich teilweise in dem heutigem Mars-Ă€hnlichem Setting wieder spiegelte. Ăhnliche Lebensformen könnten die extremen klimatischen Ănderungen im Laufe der Jahrmillionen Jahre ĂŒberdauert haben und sowohl als Fossilien wie auch als lebende Organismen zu finden sein.
Ein unterirdisches Biotop, welches sich unter den MASE-Biotopen befand, beherbergt ein schon lĂ€nger bekanntes, auĂergewöhnliches Archaeum, das SM1 Euryarchaeon (jetzt: âCandidatus Altiarchaeum hamiconexumâ). Biofilme dieses Archaeums werden an die OberflĂ€che der NĂ€hrstoffarmen Quellen gespĂŒlt und ihr Lebensstil und ihre Ultrastruktur wurden ausgiebig untersucht. Candidatus Altiarchaeum hamiconexum weist eine Doppelmembran auf - ein sehr untypischer Zellmembranaufbau in der DomĂ€ne der Archaeen. Zudem besitzt es hoch-organisierte, einzigartige ZellanhĂ€ngsel (âhamiâ), welche höchstwahrscheinlich Ă€hnlich zu bakteriellen Typ 4 Pili assembliert und verankert werden. Der N-terminale Teil der Proteinsequenz zeigte ĂŒberraschenderweise hohe Ăhnlichkeit zu S-layer Proteinen (geordnete Proteinstrukturen, die sich zu einer AuĂenhĂŒlle an die Membran anlagern), wodurch eine divergente Evolution der beiden Strukturproteine spekuliert wird. Die gesamte Hami-kodierende Gensequenz wurde entschlĂŒsselt und diente als Vorlage in heterologen Expressionsversuchen. Die auĂergewöhnliche Struktur erweist sich als vielversprechend in der Bionanotechnologie und die Resultate dieser Arbeit setzen die wesentlichen Fundamente fĂŒr weitere Experimente.
Diese Arbeit bietet verblĂŒffende Einblicke in die Welt auĂergewöhnlicher Mikroorganismen. Die vorgestellten Ergebnisse fĂŒhren zu einem besseren VerstĂ€ndnis der DiversitĂ€t und Biologie von Mikroorganismen aus extremen LebensrĂ€umen
Source Environments of the Microbiome in Perennially Ice-Covered Lake Untersee, Antarctica
Ultra-oligotrophic Lake Untersee is among the largest and deepest surface lakes of Central Queen Maud Land in East Antarctica. It is dammed at its north end by the Anuchin Glacier and the ice-cover dynamics are controlled by sublimation â not melt â as the dominating ablation process and therefore surface melt during austral summer does not provide significant amounts of water for recharge compared to subsurface melt of the Anuchin Glacier. Several studies have already described the structure and function of the microbial communities within the water column and benthic environments of Lake Untersee, however, thus far there have been no studies that examine the linkages between the lake ecosystem with that of the surrounding soils or the Anuchin Glacier. The glacier may also play an important role as a major contributor of nutrients and biota into the lake ecosystem. Based on microbial 16S rRNA amplicon sequencing, we showed that the dominant bacterial signatures in Lake Untersee, the Anuchin Glacier and its surrounding soils were affiliated with Actinobacteria, Bacteroidetes, Cyanobacteria, Firmicutes, and Proteobacteria. Aerosol and local soil depositions on the glacier surface resulted in distinct microbial communities developing in glacier ice and cryoconite holes. Based on a source tracking algorithm, we found that cryoconite microbial assemblages were a potential source of organisms, explaining up to 36% of benthic microbial mat communities in the lake. However, the major biotic sources for the lake ecosystem are still unknown, illustrating the possible importance of englacial and subglacial zones. The Anuchin Glacier may be considered as a vector in a biological sense for the bacterial colonization of the perennially ice-covered Lake Untersee. However, despite a thick perennial ice cover, observed âlift-offâ microbial mats escaping the lake make a bidirectional transfer of biota plausible. Hence, there is an exchange of biota between Lake Untersee and connective habitats possible despite the apparent sealing by a perennial ice cover and the absence of moat areas during austral summer
Biology of a widespread uncultivated archaeon that contributes to carbon fixation in the subsurface
Subsurface microbial life contributes significantly to biogeochemical cycling, yet it remains largely uncharacterized, especially its archaeal members. This 'microbial dark matter' has been explored by recent studies that were, however, mostly based on DNA sequence information only. Here, we use diverse techniques including ultrastuctural analyses to link genomics to biology for the SM1 Euryarchaeon lineage, an uncultivated group of subsurface archaea. Phylogenomic analyses reveal this lineage to belong to a widespread group of archaea that we propose to classify as a new euryarchaeal order ('Candidatus Altiarchaeales'). The representative, double-membraned species 'Candidatus Altiarchaeum hamiconexum' has an autotrophic metabolism that uses a not-yet-reported Factor(420)-free reductive acetyl-CoA pathway, confirmed by stable carbon isotopic measurements of archaeal lipids. Our results indicate that this lineage has evolved specific metabolic and structural features like nano-grappling hooks empowering this widely distributed archaeon to predominate anaerobic groundwater, where it may represent an important carbon dioxide sink
The responses of an anaerobic microorganism, Yersinia intermedia MASE-LG-1 to individual and combined simulated Martian stresses
The limits of life of aerobic microorganisms are well understood, but the responses of anaerobic microorganisms to individual and combined extreme stressors are less well known. Motivated by an interest in understanding the survivability of anaerobic microorganisms under Martian conditions, we investigated the responses of a new isolate, Yersinia intermedia MASE-LG-1 to individual and combined stresses associated with the Martian surface. This organism belongs to an adaptable and persistent genus of anaerobic microorganisms found in many environments worldwide. The effects of desiccation, low pressure, ionizing radiation, varying temperature, osmotic pressure, and oxidizing chemical compounds were investigated. The strain showed a high tolerance to desiccation, with a decline of survivability by four orders of magnitude during a storage time of 85 days. Exposure to X-rays resulted in dose-dependent inactivation for exposure up to 600 Gy while applied doses above 750 Gy led to complete inactivation. The effects of the combination of desiccation and irradiation were additive and the survivability was influenced by the order in which they were imposed. Ionizing irradiation and subsequent desiccation was more deleterious than vice versa. By contrast, the presence of perchlorates was not found to significantly affect the survival of the Yersinia strain after ionizing radiation. These data show that the organism has the capacity to survive and grow in physical and chemical stresses, imposed individually or in combination that are associated with Martian environment. Eventually it lost its viability showing that many of the most adaptable anaerobic organisms on Earth would be killed on Mars today
S-layers at second glance? Altiarchaeal grappling hooks (hami) resemble archaeal S-layer proteins in structure and sequence.
Establishing a PMA-based, molecular protocol for microbial life-dead distinction in specialized indoor environments
Microbial contamination and quality control usually relies on cultivation and quantification of colony forming units. This process, however, is laborious and gives only information on the cultivable microbial diversity.
One field, which requires quick decisions on relevant microbial contamination, is Planetary Protection.
Herein, mission goals, such as other planets, need to be protected from terrestrial microbial contamination. This includes a stringent quality control of spacecraft. To avoid delays in construction and testing, decision on spacecraft cleanliness have to be taken in timely manner.
In collaboration with the German Aerospace Center and the European Space Agency, we are establishing a novel protocol for the quick analysis of cleanroom and spacecraft contamination, based on the application of propidium monoazide (PMA), which blocks the signal from non-viable cells. Classical cleanroom contaminants were selected to form a representative mock community for all experiments. We simulated cleanroom sampling and sample concentration on filters. After exposure to radiation, desiccation and freezing, stresses which are expected during a space flight, the filters are treated with PMA, subjected to DNA extraction, microbiome analysis and quantitative PCR. In parallel to confirm our results, cultivation-based tests are performed.
Our results indicate that the protocol developed is well suited for a quick (about 14 h) quality assessment of the viability of possible contaminants. We also could show, based on the stress-exposure that the viability of the mock community is largely reduced. This protocol might also be useful for applications in the field of hygiene, food contamination control or pharmaceutical industry
The salivary microbiome as an indicator of carcinogenesis in patients with oropharyngeal squamous cell carcinoma: A pilot study
This study aimed to undertake an initial, comparative analysis of the oral salivary microbiome of patients with oral and oropharyngeal squamous cell carcinoma versus healthy controls. This project, conceived as a pilot study, included 11 patients (1 female, 10 male, mean age 61.6 yrs., SD = 8.2 yrs.) and 11 healthy controls (1 female, 10 male, mean age 46.7 yrs., SD = 15.1 yrs.). Samples of saliva were analysed by high-throughput sequencing of the 16S rRNA gene using the MiSeq platform. Sequence data revealed microbial changes that may mirror disease progression and reflect clinical preconditions such as age, alcohol consumption, tumour size, lymph node status, smoking habit, and tumour HPV-positivity. Consequently, mapping microbial changes in patients with oral and oropharyngeal squamous cell carcinomas might improve our understanding of the pathobiology of the disease, and help in the design of novel diagnostic and treatment strategies
Resilient microorganisms in dust samples of the International Space Stationâsurvival of the adaptation specialists
Background: The International Space Station (ISS) represents a unique biotope for the human crew but also for introduced microorganisms. Microbes experience selective pressures such as microgravity, desiccation, poor nutrient-availability due to cleaning, and an increased radiation level. We hypothesized that the microbial community inside the ISS is modified by adapting to these stresses. For this reason, we analyzed 8-12 years old dust samples from Russian ISS modules with major focus on the long-time surviving portion of the microbial community. We consequently assessed the cultivable microbiota of these samples in order to analyze their extremotolerant potential against desiccation, heat-shock, and clinically relevant antibiotics. In addition, we studied the bacterial and archaeal communities from the stored Russian dust samples via molecular methods (next-generation sequencing, NGS) and compared our new data with previously derived information from the US American ISS dust microbiome. Results: We cultivated and identified in total 85 bacterial, non-pathogenic isolates (17 different species) and 1 fungal isolate from the 8-12 year old dust samples collected in the Russian segment of the ISS. Most of these isolates exhibited robust resistance against heat-shock and clinically relevant antibiotics. Microbial 16S rRNA gene and archaeal 16S rRNA gene targeting Next Generation Sequencing showed signatures of human-associated microorganisms (Corynebacterium, Staphylococcus, Coprococcus etc.), but also specifically adapted extremotolerant microorganisms. Besides bacteria, the detection of archaeal signatures in higher abundance was striking. Conclusions: Our findings reveal (i) the occurrence of living, hardy microorganisms in archived Russian ISS dust samples, (ii) a profound resistance capacity of ISS microorganisms against environmental stresses, and (iii) the presence of archaeal signatures on board. In addition, we found indications that the microbial community in the Russian segment dust samples was different to recently reported US American ISS microbiota
S-layers at second glance? Altiarchaeal grappling hooks (hami) resemble archaeal S-layer proteins in structure and sequence
International audience(2015) S-layers at second glance? Altiarchaeal grappling hooks (hami) resemble archaeal S-layer proteins in structure and sequence. Front. Microbiol. 6:543. The uncultivated "Candidatus Altiarchaeum hamiconexum" (formerly known as SM1 Euryarchaeon) carries highly specialized nano-grappling hooks ("hami") on its cell surface. Until now little is known about the major protein forming these structured fibrous cell surface appendages, the genes involved or membrane anchoring of these filaments. These aspects were analyzed in depth in this study using environmental transcriptomics combined with imaging methods. Since a laboratory culture of this archaeon is not yet available, natural biofilm samples with high Ca. A. hamiconexum abundance were used for the entire analyses. The filamentous surface appendages spanned both membranes of the cell, which are composed of glycosyl-archaeol. The hami consisted of multiple copies of the same protein, the corresponding gene of which was identified via metagenome-mapped transcriptome analysis. The hamus subunit proteins, which are likely to self-assemble due to their predicted beta sheet topology, revealed no similiarity to known microbial flagella-, archaella-, fimbriae-or pili-proteins, but a high similarity to known S-layer proteins of the archaeal domain at their N-terminal region (44-47% identity). Our results provide new insights into the structure of the unique hami and their major protein and indicate their divergent evolution with S-layer proteins