43 results on '"Fleurie A"'
Search Results
2. Use of Immune Profiling Panel to assess the immune response of septic patients for prediction of worsening as a composite endpoint
- Author
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Peronnet, Estelle, Terraz, Gabriel, Cerrato, Elisabeth, Imhoff, Katia, Blein, Sophie, Brengel-Pesce, Karen, Bodinier, Maxime, Fleurie, Aurore, Rimmelé, Thomas, Lukaszewicz, Anne-Claire, Monneret, Guillaume, and Llitjos, Jean-François
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- 2024
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3. Identification of early predictive biomarkers for severe cytokine release syndrome in pediatric patients with chimeric antigen receptor T-cell therapy
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Meng Su, Luoquan Chen, Li Xie, Aurore Fleurie, Renaud Jonquieres, Qing Cao, Benshang Li, Ji Liang, and Yanjing Tang
- Subjects
CAR-T cell therapy ,cytokine release syndrome (CRS) ,biomarker ,early prediction ,decision tree model ,Immunologic diseases. Allergy ,RC581-607 - Abstract
CAR-T cell therapy is a revolutionary new treatment for hematological malignancies, but it can also result in significant adverse effects, with cytokine release syndrome (CRS) being the most common and potentially life-threatening. The identification of biomarkers to predict the severity of CRS is crucial to ensure the safety and efficacy of CAR-T therapy. To achieve this goal, we characterized the expression profiles of seven cytokines, four conventional biochemical markers, and five hematological markers prior to and following CAR-T cell infusion. Our results revealed that IL-2, IFN-γ, IL-6, and IL-10 are the key cytokines for predicting severe CRS (sCRS). Notably, IL-2 levels rise at an earlier stage of sCRS and have the potential to serve as the most effective cytokine for promptly detecting the condition’s onset. Furthermore, combining these cytokine biomarkers with hematological factors such as lymphocyte counts can further enhance their predictive performance. Finally, a predictive tree model including lymphocyte counts, IL-2, and IL-6 achieved an accuracy of 85.11% (95% CI = 0.763–0.916) for early prediction of sCRS. The model was validated in an independent cohort and achieved an accuracy of 74.47% (95% CI = 0.597–0.861). This new prediction model has the potential to become an effective tool for assessing the risk of CRS in clinical practice.
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- 2024
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4. Advancing respiratory virus diagnostics: integrating the nasal IFN-I score for improved viral detection
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Mommert-Tripon, Marine, Parraud, Delphine, Grosbois, Cloé, Gaymard, Alexandre, Cheynet, Valérie, Lina, Bruno, Oriol, Guy, Laurent, Frédéric, Dupré, Caroline, Semanas, Quentin, Bal, Antonin, Generenaz, Laurence, Pons, Sylvie, Brengel-Pesce, Karen, Guichard, Audrey, Mouton, William, Morfin, Florence, Fleurie, Aurore, and Trouillet-Assant, Sophie
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- 2024
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5. Identification of a sub-group of critically ill patients with high risk of intensive care unit-acquired infections and poor clinical course using a transcriptomic score
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Bodinier, Maxime, Monneret, Guillaume, Casimir, Marie, Fleurie, Aurore, Conti, Filippo, Venet, Fabienne, Cazalis, Marie-Angélique, Cerrato, Elisabeth, Peronnet, Estelle, Rimmelé, Thomas, Lukaszewicz, Anne-Claire, Brengel-Pesce, Karen, and Llitjos, Jean-François
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- 2023
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6. Amphiphilic proteins coassemble into multiphasic condensates and act as biomolecular surfactants
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Kelley, Fleurie M., Favetta, Bruna, Regy, Roshan Mammen, Mittal, Jeetain, and Schuster, Benjamin S.
- Published
- 2021
7. Characterization of triatomine bloodmeal sources using direct Sanger sequencing and amplicon deep sequencing methods
- Author
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Sujata Balasubramanian, Rachel Curtis-Robles, Bhagath Chirra, Lisa D. Auckland, Alan Mai, Virgilio Bocanegra-Garcia, Patti Clark, Wilhelmina Clark, Mark Cottingham, Geraldine Fleurie, Charles D. Johnson, Richard P. Metz, Shichen Wang, Nicholas J. Hathaway, Jeffrey A. Bailey, Gabriel L. Hamer, and Sarah A. Hamer
- Subjects
Medicine ,Science - Abstract
Abstract Knowledge of host associations of blood-feeding vectors may afford insights into managing disease systems and protecting public health. However, the ability of methods to distinguish bloodmeal sources varies widely. We used two methods—Sanger sequencing and amplicon deep sequencing—to target a 228 bp region of the vertebrate Cytochrome b gene and determine hosts fed upon by triatomines (n = 115) collected primarily in Texas, USA. Direct Sanger sequencing of PCR amplicons was successful for 36 samples (31%). Sanger sequencing revealed 15 distinct host species, which included humans, domestic animals (Canis lupus familiaris, Ovis aries, Gallus gallus, Bos taurus, Felis catus, and Capra hircus), wildlife (Rattus rattus, Incilius nebulifer, Sciurus carolinensis, Sciurus niger, and Odocoileus virginianus), and captive animals (Panthera tigris, Colobus spp., and Chelonoidis carbonaria). Samples sequenced by the Sanger method were also subjected to Illumina MiSeq amplicon deep sequencing. The amplicon deep sequencing results (average of 302,080 usable reads per sample) replicated the host community revealed using Sanger sequencing, and detected additional hosts in five triatomines (13.9%), including two additional blood sources (Procyon lotor and Bassariscus astutus). Up to four bloodmeal sources were detected in a single triatomine (I. nebulifer, Homo sapiens, C. lupus familiaris, and S. carolinensis). Enhanced understanding of vector-host-parasite networks may allow for integrated vector management programs focusing on highly-utilized and highly-infected host species.
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- 2022
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8. Immune Profiling Panel Gene Set Identifies Critically Ill Patients With Low Monocyte Human Leukocyte Antigen-DR Expression: Preliminary Results From the REAnimation Low Immune Status Marker (REALISM) Study
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Peronnet, Estelle, Blein, Sophie, Venet, Fabienne, Cerrato, Elisabeth, Fleurie, Aurore, Llitjos, Jean-François, Kreitmann, Louis, Terraz, Gabriel, Conti, Filippo, Gossez, Morgane, Rimmelé, Thomas, Textoris, Julien, Lukaszewicz, Anne-Claire, Brengel-Pesce, Karen, Monneret, Guillaume, Arnal, Sophie, Augris-Mathieu, Caroline, Bayle, Frederique, Caruso, Liana, Ber, Charles-Eric, Ben-Amor, Asma, Bellocq, Anne-Sophie, Benatir, Farida, Bertin-Maghit, Anne, Bertin-Maghit, Marc, Boibieux, Andre, Bouffard, Yves, Cejka, Jean-Christophe, Cerro, Valerie, Crozon-Clauzel, Jullien, Davidson, Julien, Debord-Peguet, Sophie, Delwarde, Benjamin, Deleat-Besson, Robert, Delsuc, Claire, Devigne, Bertrand, Fayolle-Pivot, Laure, Faure, Alexandre, Floccard, Bernard, Gatel, Julie, Genin, Charline, Girardot, Thibaut, Gregoire, Arnaud, Hengy, Baptiste, Huriaux, Laetitia, Jadaud, Catherine, Lepape, Alain, Leray, Veronique, Lukaszewicz, Anne-Claire, Marcotte, Guillaume, Martin, Olivier, Matray, Marie, Maucort-Boulch, Delphine, Meuret, Pascal, Monard, Celine, Moriceau, Florent, Monneret, Guillaume, Panel, Nathalie, Rahali, Najia, Rimmele, Thomas, Truc, Cyrille, Uberti, Thomas, Vallin, Helene, Venet, Fabienne, Tissot, Sylvie, Zadam, Abbes, Blein, Sophie, Brengel-Pesce, Karen, Cerrato, Elisabeth, Cheynet, Valerie, Gallet-Gorius, Emmanuelle, Guichard, Audrey, Jourdan, Camille, Koenig, Natacha, Mallet, Francois, Meunier, Boris, Moucade, Virginie, Mommert, Marine, Oriol, Guy, Pachot, Alexandre, Peronnet, Estelle, Schrevel, Claire, Tabone, Olivier, Textoris, Julien, Marcos, Javier Yugueros, Becker, Jeremie, Bequet, Frederic, Bounab, Yacine, Brajon, Florian, Canard, Bertrand, Collus, Muriel, Garcon, Nathalie, Gorse, Irene, Guyard, Cyril, Lavocat, Fabien, Leissner, Philippe, Louis, Karen, Mistretta, Maxime, Moriniere, Jeanne, Mouscaz, Yoann, Noailles, Laura, Perret, Magali, Reynier, Frederic, Riffaud, Cindy, Rol, Mary-Luz, Sapay, Nicolas, Tran, Trang, Vedrine, Christophe, Carre, Christophe, Cortez, Pierre, de Monfort, Aymeric, Florin, Karine, Fraisse, Laurent, Fugier, Isabelle, Payrard, Sandrine, Peleraux, Annick, Quemeneur, Laurence, Griffiths, Andrew, Toetsch, Stephanie, Ashton, Teri, Gough, Peter J., Berger, Scott B., Gardiner, David, Gillespie, Iain, Macnamara, Aidan, Raychaudhuri, Aparna, Smylie, Rob, Tan, Lionel, and Tipple, Craig
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- 2023
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9. Identifying sequence perturbations to an intrinsically disordered protein that determine its phase-separation behavior
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Schuster, Benjamin S., Dignon, Gregory L., Tang, Wai Shing, Kelley, Fleurie M., Ranganath, Aishwarya Kanchi, Jahnke, Craig N., Simpkins, Alison G., Regy, Roshan Mammen, Hammer, Daniel A., Good, Matthew C., and Mittal, Jeetain
- Published
- 2020
10. Surface tension and viscosity of protein condensates quantified by micropipette aspiration
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Wang, Huan, Kelley, Fleurie M., Milovanovic, Dragomir, Schuster, Benjamin S., and Shi, Zheng
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- 2021
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11. Mortality Prediction in Sepsis With an Immune-Related Transcriptomics Signature: A Multi-Cohort Analysis
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Louis Kreitmann, Maxime Bodinier, Aurore Fleurie, Katia Imhoff, Marie-Angelique Cazalis, Estelle Peronnet, Elisabeth Cerrato, Claire Tardiveau, Filippo Conti, Jean-François Llitjos, Julien Textoris, Guillaume Monneret, Sophie Blein, and Karen Brengel-Pesce
- Subjects
sepsis ,transcriptomics ,predictive modeling ,gene expression analysis ,mortality ,biomarker discovery ,Medicine (General) ,R5-920 - Abstract
BackgroundNovel biomarkers are needed to progress toward individualized patient care in sepsis. The immune profiling panel (IPP) prototype has been designed as a fully-automated multiplex tool measuring expression levels of 26 genes in sepsis patients to explore immune functions, determine sepsis endotypes and guide personalized clinical management. The performance of the IPP gene set to predict 30-day mortality has not been extensively characterized in heterogeneous cohorts of sepsis patients.MethodsPublicly available microarray data of sepsis patients with widely variable demographics, clinical characteristics and ethnical background were co-normalized, and the performance of the IPP gene set to predict 30-day mortality was assessed using a combination of machine learning algorithms.ResultsWe collected data from 1,801 arrays sampled on sepsis patients and 598 sampled on controls in 17 studies. When gene expression was assayed at day 1 following admission (1,437 arrays sampled on sepsis patients, of whom 1,161 were alive and 276 (19.2%) were dead at day 30), the IPP gene set showed good performance to predict 30-day mortality, with an area under the receiving operating characteristics curve (AUROC) of 0.710 (CI 0.652–0.768). Importantly, there was no statistically significant improvement in predictive performance when training the same models with all genes common to the 17 microarray studies (n = 7,122 genes), with an AUROC = 0.755 (CI 0.697–0.813, p = 0.286). In patients with gene expression data sampled at day 3 following admission or later, the IPP gene set had higher performance, with an AUROC = 0.804 (CI 0.643–0.964), while the total gene pool had an AUROC = 0.787 (CI 0.610–0.965, p = 0.811).ConclusionUsing pooled publicly-available gene expression data from multiple cohorts, we showed that the IPP gene set, an immune-related transcriptomics signature conveys relevant information to predict 30-day mortality when sampled at day 1 following admission. Our data also suggests that higher predictive performance could be obtained when assaying gene expression at later time points during the course of sepsis. Prospective studies are needed to confirm these findings using the IPP gene set on its dedicated measurement platform.
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- 2022
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12. Combining SARS‐CoV‐2 interferon‐gamma release assay with humoral response assessment to define immune memory profiles.
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Mouton, William, Oriol, Guy, Compagnon, Christelle, Saade, Carla, Saker, Kahina, Franc, Priscille, Mokdad, Bouchra, Fleurie, Aurore, Lacoux, Xavier, Daniel, Soizic, Berthier, Franck, Barnel, Cécile, Pozzetto, Bruno, Fassier, Jean‐Baptiste, Dubois, Valérie, Djebali, Sophia, Dubois, Maxence, Walzer, Thierry, Marvel, Jacqueline, and Brengel‐Pesce, Karen
- Subjects
IMMUNOLOGIC memory ,HUMORAL immunity ,MEDICAL personnel ,INTERFERON gamma ,INTERFERON gamma release tests - Abstract
Objectives: In the post‐SARS‐CoV‐2 pandemic era, "breakthrough infections" are still documented, due to variants of concerns (VoCs) emergence and waning humoral immunity. Despite widespread utilization, the definition of the anti‐Spike (S) immunoglobulin‐G (IgG) threshold to define protection has unveiled several limitations. Here, we explore the advantages of incorporating T‐cell response assessment to enhance the definition of immune memory profile. Methods: SARS‐CoV‐2 interferon‐gamma release assay test (IGRA) was performed on samples collected longitudinally from immunocompetent healthcare workers throughout their immunization by infection and/or vaccination, anti‐receptor‐binding domain IgG levels were assessed in parallel. The risk of symptomatic infection according to cellular/humoral immune capacities during Omicron BA.1 wave was then estimated. Results: Close to 40% of our samples were exclusively IGRA‐positive, largely due to time elapsed since their last immunization. This suggests that individuals have sustained long‐lasting cellular immunity, while they would have been classified as lacking protective immunity based solely on IgG threshold. Moreover, the Cox regression model highlighted that Omicron BA.1 circulation raises the risk of symptomatic infection while increased anti‐receptor‐binding domain IgG and IGRA levels tended to reduce it. Conclusion: The discrepancy between humoral and cellular responses highlights the significance of assessing the overall adaptive immune response. This integrated approach allows the identification of vulnerable subjects and can be of interest to guide antiviral prophylaxis at an individual level. [ABSTRACT FROM AUTHOR]
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- 2024
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13. A Vibrio cholerae BolA-Like Protein Is Required for Proper Cell Shape and Cell Envelope Integrity
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Aurore Fleurie, Abdelrahim Zoued, Laura Alvarez, Kelly M. Hines, Felipe Cava, Libin Xu, Brigid M. Davis, and Matthew K. Waldor
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BolA ,IbaG ,Vibrio cholerae ,cell envelope ,cell shape ,iron-sulfur cluster ,Microbiology ,QR1-502 - Abstract
ABSTRACT BolA family proteins are conserved in Gram-negative bacteria and many eukaryotes. While diverse cellular phenotypes have been linked to this protein family, the molecular pathways through which these proteins mediate their effects are not well described. Here, we investigated the roles of BolA family proteins in Vibrio cholerae, the cholera pathogen. Like Escherichia coli, V. cholerae encodes two BolA proteins, BolA and IbaG. However, in marked contrast to E. coli, where bolA is linked to cell shape and ibaG is not, in V. cholerae, bolA mutants lack morphological defects, whereas ibaG proved critical for the generation and/or maintenance of the pathogen’s morphology. Notably, the bizarre-shaped, multipolar, elongated, and wide cells that predominated in exponential-phase ΔibaG V. cholerae cultures were not observed in stationary-phase cultures. The V. cholerae ΔibaG mutant exhibited increased sensitivity to cell envelope stressors, including cell wall-acting antibiotics and bile, and was defective in intestinal colonization. ΔibaG V. cholerae had reduced peptidoglycan and lipid II and altered outer membrane lipids, likely contributing to the mutant’s morphological defects and sensitivity to envelope stressors. Transposon insertion sequencing analysis of ibaG’s genetic interactions suggested that ibaG is involved in several processes involved in the generation and homeostasis of the cell envelope. Furthermore, copurification studies revealed that IbaG interacts with proteins containing iron-sulfur clusters or involved in their assembly. Collectively, our findings suggest that V. cholerae IbaG controls cell morphology and cell envelope integrity through its role in biogenesis or trafficking of iron-sulfur cluster proteins. IMPORTANCE BolA-like proteins are conserved across prokaryotes and eukaryotes. These proteins have been linked to a variety of phenotypes, but the pathways and mechanisms through which they act have not been extensively characterized. Here, we unraveled the role of the BolA-like protein IbaG in the cholera pathogen Vibrio cholerae. The absence of IbaG was associated with dramatic changes in cell morphology, sensitivity to envelope stressors, and intestinal colonization defects. IbaG was found to be required for biogenesis of several components of the V. cholerae cell envelope and to interact with numerous iron-sulfur cluster-containing proteins and factors involved in their assembly. Thus, our findings suggest that IbaG governs V. cholerae cell shape and cell envelope homeostasis through its effects on iron-sulfur proteins and associated pathways. The diversity of processes involving iron-sulfur-containing proteins is likely a factor underlying the range of phenotypes associated with BolA family proteins.
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- 2019
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14. Monocyte <scp>HLA‐DR</scp> expression as an enrollment biomarker in sepsis clinical trials: Evaluation of two sampling tubes and definition of respective clinical thresholds
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Muzhda Haem Rahimi, Filippo Conti, Jean‐Francois Llitjos, Aurore Fleurie, Valérie Cerro, Fabienne Venet, Anne‐Claire Lukaszewicz, and Guillaume Monneret
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Histology ,Cell Biology ,Pathology and Forensic Medicine - Published
- 2023
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15. The Worked Example and Expertise Reversal Effect in Less Structured Tasks: Learning to Reason about Legal Cases
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Nievelstein, Fleurie, van Gog, Tamara, and van Dijck, Gijs
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The worked example effect indicates that learning by studying worked examples is more effective than learning by solving the equivalent problems. The expertise reversal effect indicates that this is only the case for novice learners; once prior knowledge of the task is available problem solving becomes more effective for learning. These effects, however, have mainly been studied using highly structured tasks. This study investigated whether they also occur on less structured tasks, in this case, learning to reason about legal cases. Less structured tasks take longer to master, and hence, examples may remain effective for a longer period of time. Novice and advanced law students received either a description of general process steps they should take, worked examples, worked examples including the process steps, or no instructional support for reasoning. Results show that worked examples were more effective for learning than problem-solving, both for novice and advanced students, even though the latter had significantly more prior knowledge. So, a worked example effect was found for both novice and advanced students, and no evidence for an expertise-reversal effect was found with these less structured tasks. (Contains 2 tables.)
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- 2013
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16. Effects of Conceptual Knowledge and Availability of Information Sources on Law Students' Legal Reasoning
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Nievelstein, Fleurie, van Gog, Tamara, and Boshuizen, Henny P. A.
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Due to the complexity of the legal domain, reasoning about law cases is a very complex skill. For novices in law school, legal reasoning is even more complex because they have not yet acquired the conceptual knowledge needed for distilling the relevant information from cases, determining applicable rules, and searching for rules and exceptions in external information sources such as lawbooks. This study investigated the role of conceptual knowledge in solving legal cases when no information sources can be used. Under such "unsupported" circumstances, novice and advanced students performed less well than domain experts, but even experts' performance was rather low. The second question addressed was whether novices even benefit from the availability of information sources (i.e., lawbook), because conceptual knowledge is prerequisite for effective use of such sources. Indeed availability of the lawbook positively affected performance only for advanced students but not for novice students. Implications for learning and instruction in the domain of law are discussed.
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- 2010
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17. Iatrogenic Transmission of Human T Cell Lymphotropic Virus Type 1 and Hepatitis C Virus through Parenteral Treatment and Chemoprophylaxis of Sleeping Sickness in Colonial Equatorial Africa
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Pépin, Jacques, Labbé, Annie-Claude, Mamadou-Yaya, Fleurie, Mbélesso, Pascal, Mbadingaï, Sylvestre, Deslandes, Sylvie, Locas, Marie-Claude, and Frost, Eric
- Published
- 2010
18. Structure Analysis of the Staphylococcus aureus UDP-N-acetyl-mannosamine Dehydrogenase Cap5O Involved in Capsular Polysaccharide Biosynthesis
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Gruszczyk, Jakub, Fleurie, Aurore, Olivares-Illana, Vanesa, Béchet, Emmanuelle, Zanella-Cleon, Isabelle, Moréra, Solange, Meyer, Philippe, Pompidor, Guillaume, Kahn, Richard, Grangeasse, Christophe, and Nessler, Sylvie
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- 2011
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19. MapZ marks the division sites and positions FtsZ rings in Streptococcus pneumoniae
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Fleurie, Aurore, Lesterlin, Christian, Manuse, Sylvie, Zhao, Chao, Cluzel, Caroline, Lavergne, Jean-Pierre, Franz-Wachtel, Mirita, Macek, Boris, Combet, Christophe, Kuru, Erkin, VanNieuwenhze, Michael S., Brun, Yves V., Sherratt, David, and Grangeasse, Christophe
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- 2014
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20. EXPLORING THE ROLE OF AGENCY ACCREDITATION IN SHAPING SERVICES FOR STREET-INVOLVED YOUTH
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Alexandra Fleurie Hunter
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street-involved youth ,homelessness ,accreditation ,service delivery ,private accreditation bodies ,standardization ,The family. Marriage. Woman ,HQ1-2044 ,Sociology (General) ,HM401-1281 - Abstract
Over the past decade, the social/human services sector across North America has continually moved towards a strong emphasis on new management systems and tools for performance measurement, as a means to track government investment and to inform services planning. This trend has contributed to the growth of a parallel industry in the form of independent accreditation bodies, which act to develop regulatory standards, as well as to perform evaluations and monitoring. In many communities accreditation now plays a significant role in defining both the eligibility of agencies to apply for government contracts, as well as the performance objectives of organizational management and service delivery. This paper looks at the service system for street-involved youth in Vancouver, Canada, as a site to explore this novel institutional arrangement. Drawing from broader literature on regulatory standards institutions, this paper outlines a research agenda to question the role of accreditation bodies in shaping child and youth care services, as well as the broader values, ideologies, and power dynamics that surround accreditation.
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- 2015
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21. Interplay of the serine/threonine-kinase StkP and the paralogs DivIVA and GpsB in pneumococcal cell elongation and division.
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Aurore Fleurie, Sylvie Manuse, Chao Zhao, Nathalie Campo, Caroline Cluzel, Jean-Pierre Lavergne, Céline Freton, Christophe Combet, Sébastien Guiral, Boumediene Soufi, Boris Macek, Erkin Kuru, Michael S VanNieuwenhze, Yves V Brun, Anne-Marie Di Guilmi, Jean-Pierre Claverys, Anne Galinier, and Christophe Grangeasse
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Genetics ,QH426-470 - Abstract
Despite years of intensive research, much remains to be discovered to understand the regulatory networks coordinating bacterial cell growth and division. The mechanisms by which Streptococcus pneumoniae achieves its characteristic ellipsoid-cell shape remain largely unknown. In this study, we analyzed the interplay of the cell division paralogs DivIVA and GpsB with the ser/thr kinase StkP. We observed that the deletion of divIVA hindered cell elongation and resulted in cell shortening and rounding. By contrast, the absence of GpsB resulted in hampered cell division and triggered cell elongation. Remarkably, ΔgpsB elongated cells exhibited a helical FtsZ pattern instead of a Z-ring, accompanied by helical patterns for DivIVA and peptidoglycan synthesis. Strikingly, divIVA deletion suppressed the elongated phenotype of ΔgpsB cells. These data suggest that DivIVA promotes cell elongation and that GpsB counteracts it. Analysis of protein-protein interactions revealed that GpsB and DivIVA do not interact with FtsZ but with the cell division protein EzrA, which itself interacts with FtsZ. In addition, GpsB interacts directly with DivIVA. These results are consistent with DivIVA and GpsB acting as a molecular switch to orchestrate peripheral and septal PG synthesis and connecting them with the Z-ring via EzrA. The cellular co-localization of the transpeptidases PBP2x and PBP2b as well as the lipid-flippases FtsW and RodA in ΔgpsB cells further suggest the existence of a single large PG assembly complex. Finally, we show that GpsB is required for septal localization and kinase activity of StkP, and therefore for StkP-dependent phosphorylation of DivIVA. Altogether, we propose that the StkP/DivIVA/GpsB triad finely tunes the two modes of peptidoglycan (peripheral and septal) synthesis responsible for the pneumococcal ellipsoid cell shape.
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- 2014
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22. Monocyte HLA‐DR expression as an enrollment biomarker in sepsis clinical trials: Evaluation of two sampling tubes and definition of respective clinical thresholds.
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Haem Rahimi, Muzhda, Conti, Filippo, Llitjos, Jean‐Francois, Fleurie, Aurore, Cerro, Valérie, Venet, Fabienne, Lukaszewicz, Anne‐Claire, and Monneret, Guillaume
- Published
- 2023
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23. Comparative analysis of the Tyr-kinases CapB1 and CapB2 fused to their cognate modulators CapA1 and CapA2 from Staphylococcus aureus.
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Jakub Gruszczyk, Vanesa Olivares-Illana, Julien Nourikyan, Aurore Fleurie, Emmanuelle Béchet, Virginie Gueguen-Chaignon, Céline Freton, Magali Aumont-Nicaise, Solange Moréra, Christophe Grangeasse, and Sylvie Nessler
- Subjects
Medicine ,Science - Abstract
A particular class of tyrosine-kinases sharing no structural similarity with eukaryotic tyrosine-kinases has been evidenced in a large array of bacterial species. These bacterial tyrosine-kinases are able to autophosphorylate on a C-terminal tyrosine-rich motif. Their autophosphorylation has been shown to play a crucial role in the biosynthesis or export of capsular polysaccharide. The analysis of the first crystal structure of the staphylococcal tyrosine kinase CapB2 associated with the activating domain of the transmembrane modulator CapA1 had brought conclusive explanation for both the autophosphorylation and activation processes. In order to explain why CapA1 activates CapB2 more efficiently than its cognate transmembrane modulator CapA2, we solved the crystal structure of CapA2B2 and compared it with the previously published structure of CapA1B2. This structural analysis did not provide the expected clues about the activation discrepancy observed between the two modulators. Staphylococcus aureus also encodes for a CapB2 homologue named CapB1 displaying more than 70% sequence similarity and being surprisingly nearly unable to autophosphorylate. We solved the crystal structure of CapA1B1 and carefully compare it with the structure of CapA1B2. The active sites of both proteins are highly conserved and the biochemical characterization of mutant proteins engineered to test the importance of small structural discrepancies identified between the two structures did not explain the inactivity of CapB1. We thus tested if CapB1 could phosphorylate other protein substrates or hydrolyze ATP. However, no activity could be detected in our in vitro assays. Taken together, these data question about the biological role of the homologous protein pairs CapA1/CapB1 and CapA2/CapB2 and we discuss about several possible interpretations.
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- 2013
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24. Interaction of Penicillin-Binding Protein 2x and Ser/Thr protein kinase StkP, two key players in Streptococcus pneumoniae R6 morphogenesis
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Morlot, C., Bayle, L., Jacq, M., Fleurie, A., Tourcier, G., Galisson, F., Vernet, T., Grangeasse, C., and Di Guilmi, A. M.
- Published
- 2013
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25. Characterization of triatomine bloodmeal sources using direct Sanger sequencing and amplicon deep sequencing methods.
- Author
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Balasubramanian, Sujata, Curtis-Robles, Rachel, Chirra, Bhagath, Auckland, Lisa D., Mai, Alan, Bocanegra-Garcia, Virgilio, Clark, Patti, Clark, Wilhelmina, Cottingham, Mark, Fleurie, Geraldine, Johnson, Charles D., Metz, Richard P., Wang, Shichen, Hathaway, Nicholas J., Bailey, Jeffrey A., Hamer, Gabriel L., and Hamer, Sarah A.
- Subjects
RACCOON ,CAPTIVE wild animals ,DOGS ,DOMESTIC animals ,TIGERS ,CATTLE - Abstract
Knowledge of host associations of blood-feeding vectors may afford insights into managing disease systems and protecting public health. However, the ability of methods to distinguish bloodmeal sources varies widely. We used two methods—Sanger sequencing and amplicon deep sequencing—to target a 228 bp region of the vertebrate Cytochrome b gene and determine hosts fed upon by triatomines (n = 115) collected primarily in Texas, USA. Direct Sanger sequencing of PCR amplicons was successful for 36 samples (31%). Sanger sequencing revealed 15 distinct host species, which included humans, domestic animals (Canis lupus familiaris, Ovis aries, Gallus gallus, Bos taurus, Felis catus, and Capra hircus), wildlife (Rattus rattus, Incilius nebulifer, Sciurus carolinensis, Sciurus niger, and Odocoileus virginianus), and captive animals (Panthera tigris, Colobus spp., and Chelonoidis carbonaria). Samples sequenced by the Sanger method were also subjected to Illumina MiSeq amplicon deep sequencing. The amplicon deep sequencing results (average of 302,080 usable reads per sample) replicated the host community revealed using Sanger sequencing, and detected additional hosts in five triatomines (13.9%), including two additional blood sources (Procyon lotor and Bassariscus astutus). Up to four bloodmeal sources were detected in a single triatomine (I. nebulifer, Homo sapiens, C. lupus familiaris, and S. carolinensis). Enhanced understanding of vector-host-parasite networks may allow for integrated vector management programs focusing on highly-utilized and highly-infected host species. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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26. Mutational dissection of the S/T-kinase StkP reveals crucial roles in cell division of Streptococcus pneumoniae
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Fleurie, Aurore, Cluzel, Caroline, Guiral, Sébastien, Freton, Céline, Galisson, Frédéric, Zanella-Cleon, Isabelle, Di Guilmi, Anne-Marie, and Grangeasse, Christophe
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- 2012
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27. Transmission of Hepatitis C virus among spouses in Cameroon and the Central African Republic
- Author
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Njouom, Richard, Lavoie, Myriam, Foupouapouognigni, Yacouba, Frost, Eric, Deslandes, Sylvie, Mamadou-Yaya, Fleurie, Mbélesso, Pascal, Mbadingai, Sylvestre, and Pépin, Jacques
- Published
- 2011
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28. Mutational dissection of the S/T-kinase StkP reveals crucial roles in cell division of Streptococcus pneumoniae
- Author
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Anne-Marie Di Guilmi, Frédéric Galisson, Christophe Grangeasse, Céline Freton, Sébastien Guiral, Aurore Fleurie, Isabelle Zanella-Cléon, and Caroline Cluzel
- Subjects
0303 health sciences ,Cell division ,030306 microbiology ,Kinase ,Biology ,Microbiology ,Phenotype ,Serine ,03 medical and health sciences ,chemistry.chemical_compound ,chemistry ,Biochemistry ,Cytoplasm ,Phosphorylation ,Peptidoglycan ,Kinase activity ,Molecular Biology ,030304 developmental biology - Abstract
Eukaryotic-like serine/threonine-kinases are involved in the regulation of a variety of physiological processes in bacteria. In Streptococcus pneumoniae, deletion of the single serine/threonine-kinase gene stkP results in an aberrant cell morphology suggesting that StkP participates in pneumococcus cell division. To understand the function of StkP, we have engineered various pneumococcus strains expressing truncated or kinase-dead forms of StkP. We show that StkP kinase activity, but also its extracellular and cytoplasmic domains per se, are required for pneumococcus cell division. Indeed, we observe that mutant cells show round or elongated shapes with non-functional septa and a chain phenotype, delocalized sites of peptidoglycan synthesis and diffused membrane StkP localization. To gain understanding of the underlying StkP-mediated regulatory mechanism, we show that StkP specifically phosphorylates in vivo the cell division protein DivIVA on threonine 201. Pneumococcus cells expressing non-phosphorylatable DivIVA-T201A possess an elongated shape with a polar bulge and aberrant spatial organization of nascent peptidoglycan. This brings the first evidence of the importance of StkP in relationship to the phosphorylation of one of its substrates in cell division. It is concluded that StkP is a multifunctional protein that plays crucial functions in pneumococcus cell shape and division.
- Published
- 2012
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29. Transmission of Hepatitis C virus among spouses in Cameroon and the Central African Republic
- Author
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Sylvie Deslandes, Eric Frost, Yacouba Foupouapouognigni, Fleurie Mamadou-Yaya, Myriam Lavoie, Sylvestre Mbadingai, Pascal Mbélesso, Richard Njouom, and Jacques Pépin
- Subjects
Adult ,Male ,Sexual transmission ,Genotype ,Concordance ,Hepatitis C virus ,Sexually Transmitted Diseases ,Hepacivirus ,medicine.disease_cause ,Serology ,Virology ,Cluster Analysis ,Humans ,Medicine ,Cameroon ,Spouses ,Phylogeny ,Aged ,Aged, 80 and over ,Transmission (medicine) ,business.industry ,virus diseases ,Hepatitis C Antibodies ,Middle Aged ,Hepatitis C ,Central African Republic ,Molecular Typing ,Cross-Sectional Studies ,Infectious Diseases ,Spouse ,RNA, Viral ,Female ,business ,Serostatus - Abstract
Heterosexual transmission of hepatitis C virus (HCV) is uncommon, with few studies undertaken in Central Africa. To determine the frequency of inter-spouse HCV transmission, cross-sectional studies of elderly individuals in Ebolowa, Cameroon and Nola, Central African Republic, in which, respectively, 24 and 83 long-term couples had been identified, were examined further. Blood samples were tested for antibody to HCV. Anti-HCV positive samples were genotyped by phylogenetic analysis of a fragment of the NS5B gene. In Nola, 4 out of 9 (44.4%) wives of anti-HCV positive husbands and 1 out of 74 (1.4%) wives of anti-HCV negative husbands were anti-HCV positive (P
- Published
- 2011
- Full Text
- View/download PDF
30. Instructional Support for Novice Law Students: Reducing Search Processes and Explaining Concepts in Cases
- Author
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Gijs van Dijck, Tamara van Gog, Fleurie Nievelstein, Henny P. A. Boshuizen, Research Group for Methodology of Law and Legal Research, RS-Research Program CELSTEC/OTEC (CO), and Department of Psychology, Education and Child Studies
- Subjects
Cognitive science ,Legal reasoning ,legal reasoning ,Working memory ,Experimental and Cognitive Psychology ,Cognition ,Legislation ,cognitive demands ,law students ,instructional support ,Arts and Humanities (miscellaneous) ,Law ,Developmental and Educational Psychology ,Mental load ,Psychology ,Cognitive psychology - Abstract
Nievelstein, F., Van Gog, T., Van Dijck, G., & Boshuizen, H. P. A. (2010). Instructional support for novice law students: Reducing search processes and explaining concepts in cases. Applied Cognitive Psychology. DOI: 10.1002/acp.1707
- Published
- 2011
- Full Text
- View/download PDF
31. Structure Analysis of the Staphylococcus aureus UDP-N-acetyl-mannosamine Dehydrogenase Cap5O Involved in Capsular Polysaccharide Biosynthesis
- Author
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Guillaume Pompidor, Vanesa Olivares-Illana, Emmanuelle Bechet, Solange Moréra, Isabelle Zanella-Cléon, Richard Kahn, Philippe Meyer, Aurore Fleurie, Sylvie Nessler, Jakub Gruszczyk, and Christophe Grangeasse
- Subjects
Staphylococcus aureus ,Molecular Sequence Data ,Molecular Conformation ,Dehydrogenase ,Biology ,Crystallography, X-Ray ,Biochemistry ,Catalysis ,Mass Spectrometry ,Microbiology ,chemistry.chemical_compound ,Protein structure ,Phagocytosis ,Biosynthesis ,Polysaccharides ,Amino Acid Sequence ,Disulfides ,Phosphorylation ,Phosphotyrosine ,Molecular Biology ,Sequence Homology, Amino Acid ,Bacterial polysaccharide ,Mannosamine ,Tyrosine phosphorylation ,Cell Biology ,chemistry ,Protein Structure and Folding ,Mutagenesis, Site-Directed ,Tyrosine ,Carbohydrate Dehydrogenases ,Oxidation-Reduction ,Cysteine - Abstract
Bacterial UDP-sugar dehydrogenases are part of the biosynthesis pathway of extracellular polysaccharides. These compounds act as important virulence factors by protecting the cell from opsonophagocytosis and complement-mediated killing. In Staphylococcus aureus, the protein Cap5O catalyzes the oxidation of UDP-N-acetyl-mannosamine to UDP-N-acetyl-mannosaminuronic acid. Cap5O is crucial for the production of serotype 5 capsular polysaccharide that prevents the interaction of bacteria with both phagocytic and nonphagocytic eukaryotic cells. However, details of its catalytic mechanism remain unknown. We thus crystallized Cap5O and solved the first structure of an UDP-N-acetyl-mannosamine dehydrogenase. This study revealed that the catalytic cysteine makes a disulfide bond that has never been observed in other structurally characterized members of the NDP-sugar dehydrogenase family. Biochemical and mutagenesis experiments demonstrated that the formation of this disulfide bridge regulates the activity of Cap5O. We also identified two arginine residues essential for Cap5O activity. Previous data suggested that Cap5O is activated by tyrosine phosphorylation, so we characterized the phosphorylation site and examined the underlying regulatory mechanism.
- Published
- 2011
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- View/download PDF
32. Expertise-related differences in conceptual and ontological knowledge in the legal domain
- Author
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Els Boshuizen, Tamara van Gog, Frans J. Prins, Fleurie Nievelstein, and RS-Research Program CELSTEC/OTEC (CO)
- Subjects
Ontological knowledge ,ontological knowledge ,Experimental and Cognitive Psychology ,Legislation ,Cognition ,Expertise ,Legal domain ,Ontology (information science) ,Psychology ,Epistemology - Abstract
Nievelstein, F., Van Gog, T., Boshuizen, H. P. A., & Prins, F. J. (2008). Expertise-related differences in conceptual and ontological knowledge in the legal domain. European Journal of Cognitive Psychology, 20, 1043–1064.
- Published
- 2008
- Full Text
- View/download PDF
33. Distracting the self: shifting attention prevents ego depletion
- Author
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Carolien Martijn, Anita Jansen, Fleurie Nievelstein, Nanne K. de Vries, Hugo J. E. M. Alberts, Clinical Psychological Science, Gezondheidsvoorlichting, RS: FPN CPS II, and RS: CAPHRI School for Public Health and Primary Care
- Subjects
Ego depletion ,media_common.quotation_subject ,Shifting attention ,Self ,Self-control ,Delay of gratification ,behavioral disciplines and activities ,Task (project management) ,Distraction ,Psychology ,General Psychology ,psychological phenomena and processes ,media_common ,Cognitive psychology - Abstract
The present research tested predictions of the strength model of self-control and delay of gratification by examining the affects of initial self-control attempts and also attention on performance. Participants completed a series of two identical physical self-control tasks, namely holding lip a weight, under varying conditions. The results showed that performance decrements can be overcome by attentional strategies. When participants distracted themselves by performing a calculation task during the second self-control measurement, they (lid not show a decline in performance. In contrast, participants who did not distract themselves and those who instead focused oil their muscles while holding up the weight, performed significantly worse on the second measurement. Interestingly, the distraction task reduced regulatory performance when it was performed before the second measurement.
- Published
- 2008
- Full Text
- View/download PDF
34. Fluorescence and absorption system for researching ultrafast processes in physics, chemistry, and biology
- Author
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Pleshanov, P. G., Fleurie, C., and Fokin, V. S.
- Published
- 1984
- Full Text
- View/download PDF
35. Role of eukaryotic-like serine/threonine kinases in bacterial cell division and morphogenesis.
- Author
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Manuse, Sylvie, Fleurie, Aurore, Zucchini, Laure, Lesterlin, Christian, and Grangeasse, Christophe
- Subjects
- *
SERINE/THREONINE kinases , *BACTERIAL enzymes , *EUKARYOTES , *CELL division , *MORPHOGENESIS , *IMMUNOMODULATORS , *PHOSPHORYLATION , *BACTERIA - Abstract
Bacteria possess a repertoire of versatile protein kinases modulating diverse aspects of their physiology by phosphorylating proteins on various amino acids including histidine, cysteine, aspartic acid, arginine, serine, threonine and tyrosine. One class of membrane serine/threonine protein kinases possesses a catalytic domain sharing a common fold with eukaryotic protein kinases and an extracellular mosaic domain found in bacteria only, named PASTA for 'Penicillin binding proteins And Serine/Threonine kinase Associated'. Over the last decade, evidence has been accumulating that these protein kinases are involved in cell division, morphogenesis and developmental processes in Firmicutes and Actinobacteria. However, observations differ from one species to another suggesting that a general mechanism of activation of their kinase activity is unlikely and that species-specific regulation of cell division is at play. In this review, we survey the latest research on the structural aspects and the cellular functions of bacterial serine/threonine kinases with PASTA motifs to illustrate the diversity of the regulatory mechanisms controlling bacterial cell division and morphogenesis. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
36. EXPLORING THE ROLE OF AGENCY ACCREDITATION IN SHAPING SERVICES FOR STREET-INVOLVED YOUTH.
- Author
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Hunter, Alexandra Fleurie
- Subjects
EDUCATIONAL accreditation ,SOCIAL services ,HUMAN services ,SERVICES for poor people ,PERFORMANCE evaluation - Abstract
Over the past decade, the social/human services sector across North America has continually moved towards a strong emphasis on new management systems and tools for performance measurement, as a means to track government investment and to inform services planning. This trend has contributed to the growth of a parallel industry in the form of independent accreditation bodies, which act to develop regulatory standards, as well as to perform evaluations and monitoring. In many communities accreditation now plays a significant role in defining both the eligibility of agencies to apply for government contracts, as well as the performance objectives of organizational management and service delivery. This paper looks at the service system for street-involved youth in Vancouver, Canada, as a site to explore this novel institutional arrangement. Drawing from broader literature on regulatory standards institutions, this paper outlines a research agenda to question the role of accreditation bodies in shaping child and youth care services, as well as the broader values, ideologies, and power dynamics that surround accreditation. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
37. Interplay of the Serine/Threonine-Kinase StkP and the Paralogs DivIVA and GpsB in Pneumococcal Cell Elongation and Division.
- Author
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Fleurie, Aurore, Manuse, Sylvie, Zhao, Chao, Campo, Nathalie, Cluzel, Caroline, Lavergne, Jean-Pierre, Freton, Céline, Combet, Christophe, Guiral, Sébastien, Soufi, Boumediene, Macek, Boris, Kuru, Erkin, VanNieuwenhze, Michael S., Brun, Yves V., Di Guilmi, Anne-Marie, Claverys, Jean-Pierre, Galinier, Anne, and Grangeasse, Christophe
- Subjects
STREPTOCOCCUS pneumoniae ,THREONINE ,BACTERIAL cells ,CELL growth ,CELL division ,CELL proliferation ,GENETICS - Abstract
Despite years of intensive research, much remains to be discovered to understand the regulatory networks coordinating bacterial cell growth and division. The mechanisms by which Streptococcus pneumoniae achieves its characteristic ellipsoid-cell shape remain largely unknown. In this study, we analyzed the interplay of the cell division paralogs DivIVA and GpsB with the ser/thr kinase StkP. We observed that the deletion of divIVA hindered cell elongation and resulted in cell shortening and rounding. By contrast, the absence of GpsB resulted in hampered cell division and triggered cell elongation. Remarkably, ΔgpsB elongated cells exhibited a helical FtsZ pattern instead of a Z-ring, accompanied by helical patterns for DivIVA and peptidoglycan synthesis. Strikingly, divIVA deletion suppressed the elongated phenotype of ΔgpsB cells. These data suggest that DivIVA promotes cell elongation and that GpsB counteracts it. Analysis of protein-protein interactions revealed that GpsB and DivIVA do not interact with FtsZ but with the cell division protein EzrA, which itself interacts with FtsZ. In addition, GpsB interacts directly with DivIVA. These results are consistent with DivIVA and GpsB acting as a molecular switch to orchestrate peripheral and septal PG synthesis and connecting them with the Z-ring via EzrA. The cellular co-localization of the transpeptidases PBP2x and PBP2b as well as the lipid-flippases FtsW and RodA in ΔgpsB cells further suggest the existence of a single large PG assembly complex. Finally, we show that GpsB is required for septal localization and kinase activity of StkP, and therefore for StkP-dependent phosphorylation of DivIVA. Altogether, we propose that the StkP/DivIVA/GpsB triad finely tunes the two modes of peptidoglycan (peripheral and septal) synthesis responsible for the pneumococcal ellipsoid cell shape. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
38. Interaction of Penicillin- Binding Protein 2x and Ser/ Thr protein kinase StkP, two key players in Streptococcus pneumoniae R6 morphogenesis.
- Author
-
Morlot, C., Bayle, L., Jacq, M., Fleurie, A., Tourcier, G., Galisson, F., Vernet, T., Grangeasse, C., and Di Guilmi, A. M.
- Subjects
BACTERIAL cells ,GROWTH factors ,PEPTIDOGLYCANS ,STREPTOCOCCUS pneumoniae ,PENICILLIN - Abstract
Bacterial cell growth and division require the co-ordinated action of peptidoglycan biosynthetic enzymes and cell morphogenesis proteins. However, the regulatory mechanisms that allow generating proper bacterial shape and thus preserving cell integrity remain largely uncharacterized, especially in ovococci. Recently, the conserved eukaryotic-like Ser/ Thr protein kinase of Streptococcus pneumoniae ( StkP) was demonstrated to play a major role in cell shape and division. Here, we investigate the molecular mechanisms underlying the regulatory function(s) of StkP and show that it involves one of the essential actors of septal peptidoglycan synthesis, Penicillin- Binding Protein 2x ( PBP2x). We demonstrate that StkP and PBP2x interact directly and are present in the same membrane-associated complex in S. pneumoniae. We further show that they both display a late-division localization pattern at the division site and that the positioning of PBP2x depends on the presence of the extracellular PASTA domains of StkP. We demonstrate that StkP and PBP2x interaction is mediated by their extracellular regions and that the complex formation is inhibited in vitro in the presence of cell wall fragments. These data suggest that the role of StkP in cell division is modulated by an interaction with PBP2x. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
39. Comparative Analysis of the Tyr-Kinases CapB1 and CapB2 Fused to Their Cognate Modulators CapA1 and CapA2 from Staphylococcus aureus.
- Author
-
Gruszczyk, Jakub, Olivares-Illana, Vanesa, Nourikyan, Julien, Fleurie, Aurore, Béchet, Emmanuelle, Gueguen-Chaignon, Virginie, Freton, Céline, Aumont-Nicaise, Magali, Moréra, Solange, Grangeasse, Christophe, and Nessler, Sylvie
- Subjects
PROTEIN-tyrosine kinases ,BACTERIAL enzymes ,AUTOPHOSPHORYLATION ,CHIMERIC proteins ,BIOSYNTHESIS ,POLYSACCHARIDES ,HYDROLYSIS ,STAPHYLOCOCCUS aureus - Abstract
A particular class of tyrosine-kinases sharing no structural similarity with eukaryotic tyrosine-kinases has been evidenced in a large array of bacterial species. These bacterial tyrosine-kinases are able to autophosphorylate on a C-terminal tyrosine-rich motif. Their autophosphorylation has been shown to play a crucial role in the biosynthesis or export of capsular polysaccharide. The analysis of the first crystal structure of the staphylococcal tyrosine kinase CapB2 associated with the activating domain of the transmembrane modulator CapA1 had brought conclusive explanation for both the autophosphorylation and activation processes. In order to explain why CapA1 activates CapB2 more efficiently than its cognate transmembrane modulator CapA2, we solved the crystal structure of CapA2B2 and compared it with the previously published structure of CapA1B2. This structural analysis did not provide the expected clues about the activation discrepancy observed between the two modulators. Staphylococcus aureus also encodes for a CapB2 homologue named CapB1 displaying more than 70% sequence similarity and being surprisingly nearly unable to autophosphorylate. We solved the crystal structure of CapA1B1 and carefully compare it with the structure of CapA1B2. The active sites of both proteins are highly conserved and the biochemical characterization of mutant proteins engineered to test the importance of small structural discrepancies identified between the two structures did not explain the inactivity of CapB1. We thus tested if CapB1 could phosphorylate other protein substrates or hydrolyze ATP. However, no activity could be detected in our in vitro assays. Taken together, these data question about the biological role of the homologous protein pairs CapA1/CapB1 and CapA2/CapB2 and we discuss about several possible interpretations. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
40. Instructional support for novice law students: Reducing search processes and explaining concepts in cases.
- Author
-
NIEVELSTEIN, FLEURIE, VAN GOG, TAMARA, VAN DIJCK, GIJS, and BOSHUIZEN, HENNY P. A.
- Subjects
LAW students ,REASONING ,SHORT-term memory ,LEARNING ,MEMORY - Abstract
Reasoning about legal cases is a complex skill that imposes a high working memory load, especially for novice students. Not only do novices lack necessary conceptual knowledge, searching through the information sources that are used during reasoning can also be assumed to impose a high additional working memory load that does not contribute to learning. Therefore, this study investigated the effects of supporting novice law students' learning by (a) providing the meaning of important concepts in the case and (b) reducing the search process by providing a condensed (relevant articles only) rather than a complete civil code. Results show that performance on a test case (for which they had to use the complete civil code) was significantly better for participants who had used the condensed civil code during learning. Performance on a conceptual knowledge post-test was significantly enhanced when students had received the concept explanations during learning. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
41. Iatrogenic Transmission of Human T Cell Lymphotropic Virus Type 1 and Hepatitis C Virus through Parenteral Treatment and Chemoprophylaxis of Sleeping Sickness in Colonial Equatorial Africa.
- Author
-
Pépinz, Jacques, Labbé, Annie-Claude, Mamadou-Yaya, Fleurie, Mbélesso, Pascal, Mbadingaï, Sylvestre, Deslandes, Sylvie, Locas, Marie-Claude, and Frost, Eric
- Subjects
IATROGENIC diseases ,HEPATITIS C treatment ,EPIDEMIC encephalitis ,CHEMOPREVENTION ,TRYPANOSOMIASIS treatment ,DISEASE risk factors - Abstract
Background. The simultaneous emergence of human immunodeficiency virus (HIV)-1 group M and HIV-2 into human populations, circa 1921-1940, is attributed to urbanization and changes in sexual behavior. We hypothesized that the initial dissemination of HIV-1, before sexual transmission predominated, was facilitated by the administration, via reusable syringes and needles, of parenteral drugs against tropical diseases. As proxies for highly lethal HIV-1, we investigated risk factors for hepatitis C virus (HCV) and human T cell lymphotropic virus 1 (HTLV-1) infections, blood-borne viruses compatible with prolonged survival, in an area known in 1936-1950 as the most virulent focus of African trypanosomiasis. Methods. Cross-sectional survey of individuals 55 years and older in Mbimou land and Nola, Central African Republic. Dried blood spots were used for HCV and HTLV-1 serologic testing and nucleic acid detection. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were measured by logistic regression. Results. The only risk factor for HCV genotype 4 infection was treatment of trypanosomiasis before 1951 (OR, 3.13; 95% CI, 1.38-7.09). HTLV-1 infection was associated with having received ⩾2 injections of pentamidine for trypanosomiasis chemoprophylaxis (adjusted OR, 2.03; 95% CI, 1.01-4.06) and with transfusions (adjusted OR, 2.82; 95% CI, 1.04-7.67). From historical data, we predicted that 59% of Mbimous 65 years and older would report treatment for trypanosomiasis before 1951; only 11% did so. Conclusions. Treatment of trypanosomiasis before 1951 may have caused iatrogenic HCV transmission. Population- wide half-yearly intramuscular pentamidine for trypanosomiasis chemoprophylaxis in 1947-1953 may have caused iatrogenic HTLV-1 transmission. These and other interventions against tropical diseases could have iatrogenically transmitted SIV
, jump-starting the HIV-1 epidemic. The excess mortality among patients with trypanosomiasis treated before 1951 supports this hypothesis. [ABSTRACT FROM AUTHOR]cpz - Published
- 2010
- Full Text
- View/download PDF
42. Distracting the Self: Shifting Attention Prevents Ego Depletion.
- Author
-
Alberts, HugoJ. E. M., Martijn, Carolien, Nievelstein, Fleurie, Jansen, Anita, and de Vries, NanneK.
- Subjects
SELF-control ,CONTROL (Psychology) ,EGO (Psychology) ,DISTRACTION ,ATTENTION ,DELAY of gratification - Abstract
The present research tested predictions of the strength model of self-control and delay of gratification by examining the effects of initial self-control attempts and also attention on performance. Participants completed a series of two identical physical self-control tasks, namely holding up a weight, under varying conditions. The results showed that performance decrements can be overcome by attentional strategies. When participants distracted themselves by performing a calculation task during the second self-control measurement, they did not show a decline in performance. In contrast, participants who did not distract themselves and those who instead focused on their muscles while holding up the weight, performed significantly worse on the second measurement. Interestingly, the distraction task reduced regulatory performance when it was performed before the second measurement. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
43. Uncovering cognitive processes: Different techniques that can contribute to cognitive load research and instruction
- Author
-
Gog, Tamara van, Kester, Liesbeth, Nievelstein, Fleurie, Giesbers, Bas, and Paas, Fred
- Subjects
- *
INSTRUCTIONAL systems , *COGNITIVE learning theory , *TEACHING methods , *INSTRUCTIONAL systems design - Abstract
Abstract: This article discusses the use of different techniques for uncovering cognitive processes, for research and instructional purposes: verbal reporting, eye tracking, and concept mapping. It is argued here that applying these techniques in research inspired by cognitive load theory may increase our understanding of how and why well-known effects of instructional formats come about (e.g., split-attention, redundancy, or worked example effects) and refine or corroborate the proposed theoretical underpinnings of such effects. This knowledge can inform instructional design, and moreover, the effects of these techniques on learning can also be direct, by embedding the techniques in instruction. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
- View/download PDF
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