9 research outputs found

    Identités allemandes à Québec : les stratégies identitaires dans le processus d'affirmation sociale d'une communauté

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    Le maintien d’éléments de la culture primaire chez un migrant, c’est-à-dire de la culture acquise dans sa région ou dans son pays d’origine, est un élément important qui, à l’aide de certaines stratégies, favorise la stabilité ainsi que la cohérence identitaire tout au long du processus de migration. M’intéressant au cas de migrants allemands de première génération qui ont choisi Québec comme ville d’accueil, j’utilise principalement les concepts de lieux d’affirmation identitaire ainsi que les stratégies qui y sont associées, pour comprendre comment leur identité primaire se développe, évolue et se transforme tout au long du processus de migration et d’intégration. La recherche que j’ai effectuée sur le terrain a initialement pris la forme d’observation participante, ce qui m’a permis de recruter 17 participants que j’ai rencontrés et interviewés lors d’entrevues semi-dirigées. L’analyse dévoile l’importance de la langue comme vecteur identitaire primaire, mais également celle de la culture et des traditions inhérentes à la région du participant. En plus des caractéristiques identitaires qui apparaissent être plus influencées par la région d’origine du migrant que par son pays en lui-même, il semble que l’identité allemande soit également tributaire de la relation, principalement au niveau de l’histoire, que ce dernier possède face à l’Allemagne avant et pendant la migration. Au final, il apparait que l’identité des migrants allemands de première génération de la ville de Québec évolue autour de la création d’un « chez-soi » (Heimat), construit à partir d’éléments rattachés à la langue, à la culture ainsi qu’aux traditions issues de leur région d’origine et qui seraient porteurs de sens au niveau individuel. Mots clés : Allemand, culture, identité, immigration, intégration, langue, minorité invisible, stratégies identitaires.The retention of components from a migrant’s primary culture (the culture acquired in his or her native region or land) is an important consideration because of the large impact it has on the migration process. With the help of certain strategies, this cultural retention fosters stability and identity consistency in migrants. While focusing my study on first-generation German migrants who chose Québec City as their new home, I primarily use the concept of identity affirmation related to locale, in addition to associated strategies. This concept allows an understanding of how identities within this population of migrants develop, evolve, and change throughout the migration and integration process. My field research initially consisted in the observation of participants: through the execution of semi-supervised interviews, I had the opportunity to recruit and meet with 17 participants. An analysis of these interviews reveals the importance of language, but also the culture and inherent traditions of native regions, as primary agents of identity. Characteristics of a migrant’s identity appear to be influenced more by his or her native region, rather than the country as a whole. Furthermore, it is apparent that a migrant’s German identity is dependent on his or her relationship with Germany (especially as regards historical events) before and during the time of migration. Finally, this research manifests that the identity of first-generation German migrants in Québec City evolves around the creation of a Heimat (homeland). This last is constructed using elements from the migrants’ language, culture, and regional traditions, which convey special meaning at the individual level. Keywords: German, culture, identity, immigration, integration, language, invisible minorities, identity strategies

    Mesure de conductivité électrique tétrapolaire du cartilage articulaire bovin

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    Contexte biophysique -- Conductivité apparente théorique -- Mesures de conductivité électrique expérimentales

    Free-Energy Landscape of the Amino-Terminal Fragment of Huntingtin in Aqueous Solution

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    The first exon of Huntingtin—a protein with multiple biological functions whose misfolding is related to Huntington’s disease—modulates its localization, aggregation, and function within the cell. It is composed of a 17-amino-acid amphipathic segment (Htt17), an amyloidogenic segment of consecutive glutamines (Q(N)), and a proline-rich segment. Htt17 is of fundamental importance: it serves as a membrane anchor to control the localization of huntingtin, it modulates huntingtin’s function through posttranslational modifications, and it controls the self-assembly of the amyloidogenic Q(N) segment into oligomers and fibrils. Experimentally, the conformational ensemble of the Htt17 monomer, as well as the impact of the polyglutamine and proline-rich segments, remains, however, mostly uncharacterized at the atomic level due to its intrinsic flexibility. Here, we unveil the free-energy landscape of Htt17, Htt17Q(17), and Htt17Q(17)P(11) using Hamiltonian replica exchange combined with well-tempered metadynamics. We characterize the free-energy landscape of these three fragments in terms of a few selected collective variables. Extensive simulations reveal that the free energy of Htt17 is dominated by a broad ensemble of configurations that agree with solution NMR chemical shifts. Addition of Q(17) at its carboxy-terminus reduces the extent of the main basin to more extended configurations of Htt17 with lower helix propensity. Also, the aliphatic carbons of Q(17) partially sequester the nonpolar amino acids of Htt17. For its part, addition of Q(17)P(11) shifts the overall landscape to a more extended and helical Htt17 stabilized by interactions with Q(17) and P(11), which almost exclusively form a PPII-helix, as well as by intramolecular H-bonds and salt bridges. Our characterization of Huntingtin’s amino-terminus provides insights into the structural origin of its ability to oligomerize and interact with phospholipid bilayers, processes closely linked to the biological functions of this protein

    Probing the Huntingtin 1-17 Membrane Anchor on a Phospholipid Bilayer by Using All-Atom Simulations

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    AbstractMislocalization and aggregation of the huntingtin protein are related to Huntington’s disease. Its first exon—more specifically the first 17 amino acids (Htt17)—is crucial for the physiological and pathological functions of huntingtin. It regulates huntingtin’s activity through posttranslational modifications and serves as an anchor to membrane-containing organelles of the cell. Recently, structure and orientation of the Htt17 membrane anchor were determined using a combined solution and solid-state NMR approach. This prompted us to refine this model by investigating the dynamics and thermodynamics of this membrane anchor on a POPC bilayer using all-atom, explicit solvent molecular dynamics and Hamiltonian replica exchange. Our simulations are combined with various experimental measurements to generate a high-resolution atomistic model for the huntingtin Htt17 membrane anchor on a POPC bilayer. More precisely, we observe that the single α-helix structure is more stable in the phospholipid membrane than the NMR model obtained in the presence of dodecylphosphocholine detergent micelles. The resulting Htt17 monomer has its hydrophobic plane oriented parallel to the bilayer surface. Our results further unveil the key residues interacting with the membrane in terms of hydrogen bonds, salt-bridges, and nonpolar contributions. We also observe that Htt17 equilibrates at a well-defined insertion depth and that it perturbs the physical properties—order parameter, thickness, and area per lipid—of the bilayer in a manner that could favor its dimerization. Overall, our observations reinforce and refine the NMR measurements on the Htt17 membrane anchor segment of huntingtin that is of fundamental importance to its biological functions

    Corilagin and 1,3,6-Tri-O-galloyl-β -D-glucose : potential inhibitors of SARS-CoV-2 variants

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    The COVID-19 disease caused by the virus SARS-CoV-2, first detected in December 2019, is still emerging through virus mutations. Although almost under control in some countries due to effective vaccines that are mitigating the worldwide pandemic, the urgency to develop additional vaccines and therapeutic treatments is imperative. In this work, the natural polyphenols corilagin and 1,3,6-tri-Ogalloy-β-D-glucose (TGG) are investigated to determine the structural basis of inhibitor interactions as potential candidates to inhibit SARS-CoV-2 viral entry into target cells. First, the therapeutic potential of the ligands are assessed on the ACE2/wild-type RBD. We first use molecular docking followed by molecular dynamics, to take into account the conformational flexibility that plays a significant role in ligand binding and that cannot be captured using only docking, and then analyze more precisely the affinity of these ligands using MMPBSA binding free energy. We show that both ligands bind to the ACE2/wild-type RBD interface with good affinities which might prevent the ACE2/RBD association. Second, we confirm the potency of these ligands to block the ACE2/RBD association using a combination of surface plasmon resonance and biochemical inhibition assays. These experiments confirm that TGG and, to a lesser extent, corilagin, inhibit the binding of RBD to ACE2. Both experiments and simulations show that the ligands interact preferentially with RBD, while weak binding is observed with ACE2, hence, avoiding potential physiological side-effects induced by the inhibition of ACE2. In addition to the wild-type RBD, we also study numerically three RBD mutations (E484K, N501Y and E484K/N501Y) found in the main SARS-CoV-2 variants of concerns. We find that corilagin could be as effective for RBD/E484K but less effective for the RBD/N501Y and RBD/E484K-N501Y mutants, while TGG strongly binds at relevant locations to all three mutants, demonstrating the significant interest of these molecules as potential inhibitors for variants of SARSCoV-2

    Evaluation of an interprofessional primary healthcare team as a new model of primary care in Quebec: a protocol for a type 2 effectiveness-implementation hybrid study

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    Introduction One family medicine group (FMG) in Quebec has commenced a 5-year pilot project, which is herein referred to as the Archimède model, to implement a patient-centred model based on interprofessional care and the optimal use of healthcare providers’ practice scopes. A research project will be conducted to: (1) assess this model’s effect on the FMG’s operational performance, and its users’ resource utilisation at the public health system level; (2) investigate its optimisation with respect to professional roles, interprofessional teamwork and patient-centredness and (3) document users’ experience with the model. The aim of this article is to describe the protocol that will be used for this research.Methods and analysis A hybrid implementation approach (type 2 model) will be used. We will collect both quantitative and qualitative data. Regarding the quantitative dimension, and because this is a single-unit intervention study, we will use either or both synthetic control methods and one-sample generalised linear models for analyses at the FMG level. To evaluate the broader impact of Archimède on the public health system, we will use mixed-effects models and propensity score matching methods. Regarding the qualitative research dimension, using an interpretative descriptive approach, we will document users’ experience and identify the factors that optimise professional scopes of practice, collaborative practices and patient-centredness. We will conduct individual in-depth semistructured interviews with healthcare providers, administrative staff, stakeholders involved in the Archimède model implementation and patients.Ethics and dissemination This study was approved by the Ethics Committee of the Sectoral Research in Population Health and Primary Care of the Centre intégré universitaire de santé et de services sociaux de la Capitale-Nationale (#2019-1503). The results of the investigation will be presented to the stakeholders involved in the advisory committees and at several scientific conferences. Manuscripts will be submitted to peer-reviewed journals

    Free-Energy Landscape of the Amino-Terminal Fragment of Huntingtin in Aqueous Solution

    No full text
    The first exon of Huntingtin—a protein with multiple biological functions whose misfolding is related to Huntington’s disease—modulates its localization, aggregation, and function within the cell. It is composed of a 17-amino-acid amphipathic segment (Htt17), an amyloidogenic segment of consecutive glutamines (Q(N)), and a proline-rich segment. Htt17 is of fundamental importance: it serves as a membrane anchor to control the localization of huntingtin, it modulates huntingtin’s function through posttranslational modifications, and it controls the self-assembly of the amyloidogenic Q(N) segment into oligomers and fibrils. Experimentally, the conformational ensemble of the Htt17 monomer, as well as the impact of the polyglutamine and proline-rich segments, remains, however, mostly uncharacterized at the atomic level due to its intrinsic flexibility. Here, we unveil the free-energy landscape of Htt17, Htt17Q(17), and Htt17Q(17)P(11) using Hamiltonian replica exchange combined with well-tempered metadynamics. We characterize the free-energy landscape of these three fragments in terms of a few selected collective variables. Extensive simulations reveal that the free energy of Htt17 is dominated by a broad ensemble of configurations that agree with solution NMR chemical shifts. Addition of Q(17) at its carboxy-terminus reduces the extent of the main basin to more extended configurations of Htt17 with lower helix propensity. Also, the aliphatic carbons of Q(17) partially sequester the nonpolar amino acids of Htt17. For its part, addition of Q(17)P(11) shifts the overall landscape to a more extended and helical Htt17 stabilized by interactions with Q(17) and P(11), which almost exclusively form a PPII-helix, as well as by intramolecular H-bonds and salt bridges. Our characterization of Huntingtin’s amino-terminus provides insights into the structural origin of its ability to oligomerize and interact with phospholipid bilayers, processes closely linked to the biological functions of this protein
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