14 results on '"Louise Conrard"'
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2. Author Reply to Peer Reviews of Drosophila cap-binding protein eiF4EHP promotes translation via a 3′UTR-dependent mechanism under hypoxia and contributes to fruit fly adaptation to oxygen variations
- Author
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Manfei Liang, Clara Hody, Vanessa Yammine, Romuald Soin, Yuqiu Sun, Xing Lin, Xiaoying Tian, Romane Meurs, Camille Perdrau, Nadège Delacourt, Fabienne Andris, Louise Conrard, Véronique Kruys, and Cyril Gueydan
- Published
- 2022
3. Drosophila cap-binding protein eiF4EHP promotes translation via a 3’UTR-dependent mechanism under hypoxia and contributes to fruit fly adaptation to oxygen variations
- Author
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Manfei Liang, Clara Hody, Vanessa Yammine, Romuald Soin, Yuqiu Sun, Xing Lin, Xiaoying Tian, Romane Meurs, Camille Perdrau, Nadège Delacourt, Fabienne Andris, Louise Conrard, Véronique Kruys, and Cyril Gueydan
- Abstract
Hypoxia induces profound modifications in gene expression program enabling eukaryotic cells to adapt to lowered ATP supply resulting from the blockade of oxidative phosphorylation. One major consequence of oxygen deprivation is the massive repression of protein synthesis, leaving a limited set of mRNAs to be translated. D. melanogaster is strongly resistant to oxygen fluctuations, however the mechanisms allowing specific mRNA to be translated in hypoxia are still unknown. Here, we show that Ldh mRNA encoding lactate dehydrogenase is highly translated in hypoxia by a mechanism involving its 3’ untranslated region. Furthermore, we identified the cap-binding protein eiF4HP as a main factor involved in 3’UTR-dependent translation under hypoxia. In accordance with this observation, we show that eiF4EHP is necessary for Drosophila development under low oxygen concentrations and contributes to Drosophila mobility after hypoxic challenge. Altogether, our data bring new insight into mechanisms contributing to Drosophila adaptation to oxygen variations.
- Published
- 2022
4. Spatial Relationship and Functional Relevance of Three Lipid Domain Populations at the Erythrocyte Surface
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Rumiana Dimova, Jan Steinkühler, Louise Conrard, Anne-Sophie Cloos, Amaury Stommen, Donatienne Tyteca, and Hélène Pollet
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0301 basic medicine ,Calcium exchanges ,Erythrocytes ,Physiology ,Calcium pump ,G(M1) Ganglioside ,Ion Channels ,Calcium in biology ,lcsh:Physiology ,lcsh:Biochemistry ,Plasma Membrane Calcium-Transporting ATPases ,03 medical and health sciences ,chemistry.chemical_compound ,Membrane Microdomains ,PMCA ,Phosphatidylcholine ,Fluorescence microscope ,Humans ,lcsh:QD415-436 ,Cytoskeleton ,Cell Shape ,Ion channel ,Fluorescence microscopy ,Mechanical stimulation ,lcsh:QP1-981 ,Erythrocyte Membrane ,PIEZO1 ,technology, industry, and agriculture ,Piezo1 ,PDMS stretching ,Biomechanical Phenomena ,Cholesterol ,030104 developmental biology ,chemistry ,Phosphatidylcholines ,Biophysics ,lipids (amino acids, peptides, and proteins) ,Sphingomyelin - Abstract
Background/Aims: Red blood cells (RBC) have been shown to exhibit stable submicrometric lipid domains enriched in cholesterol (chol), sphingomyelin (SM), phosphatidylcholine (PC) or ganglioside GM1, which represent the four main lipid classes of their outer plasma membrane leaflet. However, whether those lipid domains co-exist at the RBC surface or are spatially related and whether and how they are subjected to reorganization upon RBC deformation are not known. Methods: Using fluorescence and/or confocal microscopy and well-validated probes, we compared these four lipid-enriched domains for their abundance, curvature association, lipid order, temperature dependence, spatial dissociation and sensitivity to RBC mechanical stimulation. Results: Our data suggest that three populations of lipid domains with decreasing abundance coexist at the RBC surface: (i) chol-enriched ones, associated with RBC high curvature areas; (ii) GM1/PC/chol-enriched ones, present in low curvature areas; and (iii) SM/PC/chol-enriched ones, also found in low curvature areas. Whereas chol-enriched domains gather in increased curvature areas upon RBC deformation, low curvature-associated lipid domains increase in abundance either upon calcium influx during RBC deformation (GM1/PC/chol-enriched domains) or upon secondary calcium efflux during RBC shape restoration (SM/PC/chol-enriched domains). Hence, abrogation of these two domain populations is accompanied by a strong impairment of the intracellular calcium balance. Conclusion: Lipid domains could contribute to calcium influx and efflux by controlling the membrane distribution and/or the activity of the mechano-activated ion channel Piezo1 and the calcium pump PMCA. Whether this results from lipid domain biophysical properties, the strength of their anchorage to the underlying cytoskeleton and/or their correspondence with inner plasma membrane leaflet lipids remains to be demonstrated.
- Published
- 2018
5. Aberrant Membrane Composition and Biophysical Properties Impair Erythrocyte Morphology and Functionality in Elliptocytosis
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Juliette Vanderroost, Donatienne Tyteca, Catherine Léonard, Amaury Stommen, Christiane Vermylen, Miikka Vikkula, Adrien Paquot, Manuel Guthmann, Didier Vertommen, Louise Conrard, Hélène Pollet, Mélanie Carquin, Maxime Lingurski, Giulio G. Muccioli, Laurent Gatto, Theodore Killian, Mark H. Rider, Patrick Van Der Smissen, Marine Ghodsi, Sébastien Pyr dit Ruys, Pascal Brouillard, Anne-Sophie Cloos, and UCL - SSS/DDUV - Institut de Duve
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0301 basic medicine ,Erythrocytes ,lysophosphatidylserine ,Membrane Fluidity ,Hereditary elliptocytosis ,lcsh:QR1-502 ,amitriptyline ,spectrin cytoskeleton ,Ca2+ ,lipid domains ,membrane asymmetry ,membrane rigidity ,membrane curvature ,oxidative stress ,Biochemistry ,Article ,lcsh:Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,Elliptocytosis ,0302 clinical medicine ,Membrane Microdomains ,hemic and lymphatic diseases ,medicine ,Humans ,Spectrin ,Molecular Biology ,Erythrocyte Membrane ,Elliptocytosis, Hereditary ,Phosphatidylserine ,medicine.disease ,Cell biology ,Red blood cell ,Oxidative Stress ,030104 developmental biology ,medicine.anatomical_structure ,Cholesterol ,chemistry ,Lysophosphatidylserine ,Membrane curvature ,030220 oncology & carcinogenesis ,Acid sphingomyelinase ,Lysophospholipids ,medicine.drug - Abstract
[Authors equally contributed to the work : Hélène Pollet, Anne-Sophie Cloos] Red blood cell (RBC) deformability is altered in inherited RBC disorders but the mechanism behind this is poorly understood. Here, we explored the molecular, biophysical, morphological, and functional consequences of α-spectrin mutations in a patient with hereditary elliptocytosis (pEl) almost exclusively expressing the Pro260 variant of SPTA1 and her mother (pElm), heterozygous for this mutation. At the molecular level, the pEI RBC proteome was globally preserved but spectrin density at cell edges was increased. Decreased phosphatidylserine vs. increased lysophosphatidylserine species, and enhanced lipid peroxidation, methemoglobin, and plasma acid sphingomyelinase (aSMase) activity were observed. At the biophysical level, although membrane transversal asymmetry was preserved, curvature at RBC edges and rigidity were increased. Lipid domains were altered for membrane:cytoskeleton anchorage, cholesterol content and response to Ca2+ exchange stimulation. At the morphological and functional levels, pEl RBCs exhibited reduced size and circularity, increased fragility and impaired membrane Ca2+ exchanges. The contribution of increased membrane curvature to the pEl phenotype was shown by mechanistic experiments in healthy RBCs upon lysophosphatidylserine membrane insertion. The role of lipid domain defects was proved by cholesterol depletion and aSMase inhibition in pEl. The data indicate that aberrant membrane content and biophysical properties alter pEl RBC morphology and functionality.
- Published
- 2020
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6. Nanoscale membrane architecture of healthy and pathological red blood cells
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David Alsteens, Donatienne Tyteca, Andra-Cristina Dumitru, Mégane A. Poncin, Louise Conrard, and Yves F. Dufrêne
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0301 basic medicine ,Chemistry ,Cell ,02 engineering and technology ,021001 nanoscience & nanotechnology ,medicine.disease ,Microcirculation ,Hereditary spherocytosis ,03 medical and health sciences ,Red blood cell ,030104 developmental biology ,Membrane ,medicine.anatomical_structure ,medicine ,Biophysics ,General Materials Science ,0210 nano-technology ,Cytoskeleton ,Nanoscopic scale ,Nanomechanics - Abstract
Red blood cells feature remarkable mechanical properties while navigating through microcirculation vessels and during spleen filtration. An unusual combination of plasma membrane and cytoskeleton physical properties allows red blood cells to undergo extensive deformation. Here we used atomic force microscopy multiparametric imaging to probe how cellular organization influences nanoscale and global mechanical properties of cells in both physiological and pathological conditions. Our data obtained in native conditions confirmed that, compared to healthy cells, cells from patients with hereditary spherocytosis are stiffer. Through vertical segmentation of the cell elasticity, we found that healthy and pathological cells display nanoscale architecture with an increasing stiffness along the direction of the applied force. By decoupling the mechanical response of the plasma membrane from its underlying cytoskeleton, we find that both components show altered properties in pathological conditions. Nanoscale multiparametric imaging also revealed lipid domains that exhibit differential mechanical properties than the bulk membrane in both healthy and pathological conditions. Thanks to correlated AFM-fluorescence imaging, we identified submicrometric sphingomyelin-enriched lipid domains of variable stiffness at the red blood cell surface. Our experiments provide novel insights into the interplay between nanoscale organization of red blood cell plasma membrane and their nanomechanical properties. Overall, this work contributes to a better understanding of the complex relationship between cellular nanoscale organization, cellular nanomechanics and how this 3D organization is altered in pathological conditions.
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- 2020
7. High-resolution mapping and recognition of lipid domains using AFM with toxin-derivatized probes
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Maria Veiga-da-Cunha, Donatienne Tyteca, Cristina Lo Giudice, Andra C. Dumitru, David Alsteens, Sylvie Derclaye, Louise Conrard, and Patrick Henriet
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0301 basic medicine ,Clostridium perfringens ,Membrane lipids ,Bacterial Toxins ,Lipid Bilayers ,Microscopy, Atomic Force ,Catalysis ,Hemolysin Proteins ,03 medical and health sciences ,Membrane Microdomains ,Molecular recognition ,Elastic Modulus ,Microscopy ,Materials Chemistry ,Lipid bilayer ,Toxins, Biological ,Atomic force microscopy ,Chemistry ,technology, industry, and agriculture ,Metals and Alloys ,General Chemistry ,Peptide Fragments ,Sphingomyelins ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Cholesterol ,030104 developmental biology ,Membrane ,Phosphatidylcholines ,Ceramics and Composites ,Biophysics ,Surface modification ,lipids (amino acids, peptides, and proteins) ,Sphingomyelin - Abstract
Cellular membrane lateral organization, in particular the assembly of lipids in domains, is difficult to evaluate at high resolution. Here, we used atomic force microscopy (AFM) to investigate at high-resolution lipid membranes containing variable amounts of sphingomyelin (SM) and cholesterol (Chol), two abundant membrane lipids. To this end, we developed new AFM tip functionalization strategies to specifically probe SM and Chol. Multiparametric AFM imaging allowed us to highlight the lateral submicrometric organization of these two lipids within lipid bilayers through the simultaneous topographic evidence of different phase regimes together with the extraction of their nanomechanical properties and the specific detection of lipid moieties by functionalized AFM probes. The combination of AFM topography and nanomechanical mapping with specific probes for molecular recognition of lipids represents a novel approach to identify lipid-enriched domains in supported bilayers and offers a unique perspective to directly observe lipid assemblies in living cells.
- Published
- 2018
8. Regulation of Membrane Calcium Transport Proteins by the Surrounding Lipid Environment
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Donatienne Tyteca, Louise Conrard, UCL - SSS/DDUV - Institut de Duve, and UCL - SSS/DDUV/CELL - Biologie cellulaire
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0301 basic medicine ,Cell signaling ,Non-annular lipids ,lcsh:QR1-502 ,Review ,lipid domain ,Biochemistry ,Annular lipids ,lcsh:Microbiology ,Cellular life ,membrane lipid packing ,chemistry.chemical_compound ,0302 clinical medicine ,Transport protein ,Membrane ,Cholesterol ,Membrane curvature ,acidic phospholipids ,lipids (amino acids, peptides, and proteins) ,membrane thickness ,Signal Transduction ,Calcium exchanges ,Membrane thickness ,chemistry.chemical_element ,Calcium ,Biophysical Phenomena ,03 medical and health sciences ,Membrane Lipids ,Plasma Membrane Calcium-Transporting ATPases ,cell signaling ,Humans ,non-annular lipids ,Acidic phospholipids ,Molecular Biology ,Lipid domain ,Sphingolipids ,sphingolipids ,annular lipids ,Cell Membrane ,cholesterol ,Sphingolipid ,030104 developmental biology ,chemistry ,membrane curvature ,Biophysics ,calcium exchanges ,030217 neurology & neurosurgery ,Membrane lipid packing - Abstract
Calcium ions (Ca2+) are major messengers in cell signaling, impacting nearly every aspect of cellular life. Those signals are generated within a wide spatial and temporal range through a large variety of Ca2+ channels, pumps, and exchangers. More and more evidences suggest that Ca2+ exchanges are regulated by their surrounding lipid environment. In this review, we point out the technical challenges that are currently being overcome and those that still need to be defeated to analyze the Ca2+ transport protein−lipid interactions. We then provide evidences for the modulation of Ca2+ transport proteins by lipids, including cholesterol, acidic phospholipids, sphingolipids, and their metabolites. We also integrate documented mechanisms involved in the regulation of Ca2+ transport proteins by the lipid environment. Those include: (i) Direct interaction inside the protein with non-annular lipids; (ii) close interaction with the first shell of annular lipids; (iii) regulation of membrane biophysical properties (e.g., membrane lipid packing, thickness, and curvature) directly around the protein through annular lipids; and (iv) gathering and downstream signaling of several proteins inside lipid domains. We finally discuss recent reports supporting the related alteration of Ca2+ and lipids in different pathophysiological events and the possibility to target lipids in Ca2+-related diseases.
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- 2019
9. Contribution of plasma membrane lipid domains to red blood cell (re)shaping
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M. Guthmann, Donatienne Tyteca, Catherine Léonard, Philippe Gailly, Hélène Pollet, Louise Conrard, Mélanie Carquin, M. P. Mingeot-Leclercq, P. Van Der Smissen, and Christiane Vermylen
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0301 basic medicine ,Erythrocytes ,Membrane lipids ,Science ,Cell ,030204 cardiovascular system & hematology ,Biology ,Models, Biological ,Article ,03 medical and health sciences ,Elliptocytosis ,Membrane Lipids ,0302 clinical medicine ,Membrane Microdomains ,Erythrocyte Deformability ,medicine ,Erythrocyte deformability ,Humans ,Cell Shape ,Cellular Senescence ,Multidisciplinary ,Erythrocyte Membrane ,Elliptocytosis, Hereditary ,Cell biology ,Red blood cell ,030104 developmental biology ,medicine.anatomical_structure ,Membrane ,Cholesterol ,Medicine ,lipids (amino acids, peptides, and proteins) ,Calcium ,Cellular model ,Sphingomyelin - Abstract
Although lipid domains have been evidenced in several living cell plasma membranes, their roles remain largely unclear. We here investigated whether they could contribute to function-associated cell (re)shaping. To address this question, we used erythrocytes as cellular model since they (i) exhibit a specific biconcave shape, allowing for reversible deformation in blood circulation, which is lost by membrane vesiculation upon aging; and (ii) display at their outer plasma membrane leaflet two types of submicrometric domains differently enriched in cholesterol and sphingomyelin. We here reveal the specific association of cholesterol- and sphingomyelin-enriched domains with distinct curvature areas of the erythrocyte biconcave membrane. Upon erythrocyte deformation, cholesterol-enriched domains gathered in high curvature areas. In contrast, sphingomyelin-enriched domains increased in abundance upon calcium efflux during shape restoration. Upon erythrocyte storage at 4 °C (to mimick aging), lipid domains appeared as specific vesiculation sites. Altogether, our data indicate that lipid domains could contribute to erythrocyte function-associated (re)shaping.
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- 2017
10. Lipid Domains at the Plasma Membrane of Red Blood Cells: Organization and Involvement in Deformation
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Louise Conrard
- Subjects
Membrane ,Materials science ,Biophysics ,Plasma ,Deformation (meteorology) - Published
- 2018
11. Spatial Relationship and Functional Relevance of Three Lipid Domain Populations at the Erythrocyte Surface
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Amaury Stommen, Hélène Pollet, Donatienne Tyteca, and Louise Conrard
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Physics ,Surface (mathematics) ,Biophysics ,Relevance (information retrieval) ,Spatial relationship ,Biological system ,Domain (software engineering) - Published
- 2019
12. Plasma Membrane Lipid Domains as Platforms for Vesicle Biogenesis and Shedding?
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Louise Conrard, Donatienne Tyteca, Hélène Pollet, and Anne-Sophie Cloos
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0301 basic medicine ,raft ,Ceramide ,Membrane lipids ,lcsh:QR1-502 ,Review ,red blood cell ,Models, Biological ,Biochemistry ,lcsh:Microbiology ,Biophysical Phenomena ,Extracellular Vesicles ,03 medical and health sciences ,chemistry.chemical_compound ,Membrane Microdomains ,0302 clinical medicine ,medicine ,Animals ,Humans ,oxidative stress ,ceramide ,sphingomyelinase ,Molecular Biology ,calcium ,lipid domains ,Chemistry ,Vesicle ,Microvesicle ,cholesterol ,cytoskeleton ,Microvesicles ,Cell biology ,Red blood cell ,030104 developmental biology ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,microvesicle ,Sphingomyelin ,Biogenesis - Abstract
Extracellular vesicles (EVs) contribute to several pathophysiological processes and appear as emerging targets for disease diagnosis and therapy. However, successful translation from bench to bedside requires deeper understanding of EVs, in particular their diversity, composition, biogenesis and shedding mechanisms. In this review, we focus on plasma membrane-derived microvesicles (MVs), far less appreciated than exosomes. We integrate documented mechanisms involved in MV biogenesis and shedding, focusing on the red blood cell as a model. We then provide a perspective for the relevance of plasma membrane lipid composition and biophysical properties in microvesiculation on red blood cells but also platelets, immune and nervous cells as well as tumor cells. Although only a few data are available in this respect, most of them appear to converge to the idea that modulation of plasma membrane lipid content, transversal asymmetry and lateral heterogeneity in lipid domains may play a significant role in the vesiculation process. We suggest that lipid domains may represent platforms for inclusion/exclusion of membrane lipids and proteins into MVs and that MVs could originate from distinct domains during physiological processes and disease evolution.
- Published
- 2018
13. Cholesterol Forms Submicrometric Domains on the Living Erythrocyte Membrane
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Mélanie Carquin, Maria Veiga-da-Cunha, Louise Conrard, Donatienne Tyteca, Pierre J. Courtoy, Hélène Pollet, and Patrick Van Der Smissen
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chemistry.chemical_compound ,Erythrocyte membrane ,chemistry ,Cholesterol ,Genetics ,Regulator ,Membrane fluidity ,Biophysics ,Distribution (pharmacology) ,Molecular Biology ,Biochemistry ,Biotechnology - Abstract
Cholesterol is a major regulator of plasma membrane fluidity and deformability but its lateral distribution is poorly understood due to lack of suitable vital probes. The objective of our study was...
- Published
- 2015
14. Cholesterol segregates into submicrometric domains at the living erythrocyte membrane: evidence and regulation
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Donatienne Tyteca, Maria Veiga-da-Cunha, Patrick Van Der Smissen, Pierre J. Courtoy, Louise Conrard, Mélanie Carquin, Hélène Pollet, and Antoine Cominelli
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Boron Compounds ,Bacterial Toxins ,Biology ,law.invention ,Cell Line ,Myoblasts ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Hemolysin Proteins ,Mice ,Membrane Microdomains ,Confocal microscopy ,law ,Membrane fluidity ,Animals ,Humans ,Spectrin ,Cytoskeleton ,Molecular Biology ,Pharmacology ,Cholesterol ,Erythrocyte Membrane ,Temperature ,Cell Biology ,Cell biology ,Sphingomyelins ,Membrane ,chemistry ,Molecular Medicine ,lipids (amino acids, peptides, and proteins) ,Sphingomyelin ,mCherry - Abstract
Although cholesterol is essential for membrane fluidity and deformability, the level of its lateral heterogeneity at the plasma membrane of living cells is poorly understood due to lack of appropriate probe. We here report on the usefulness of the D4 fragment of Clostridium perfringens toxin fused to mCherry (theta*), as specific, non-toxic, sensitive and quantitative cholesterol-labeling tool, using erythrocyte flat membrane. By confocal microscopy, theta* labels cholesterol-enriched submicrometric domains in coverslip-spread but also gel-suspended (non-stretched) fresh erythrocytes, suggesting in vivo relevance. Cholesterol domains on spread erythrocytes are stable in time and space, restricted by membrane:spectrin anchorage via 4.1R complexes, and depend on temperature and sphingomyelin, indicating combined regulation by extrinsic membrane:cytoskeleton interaction and by intrinsic lipid packing. Cholesterol domains partially co-localize with BODIPY-sphingomyelin-enriched domains. In conclusion, we show that theta* is a useful vital probe to study cholesterol organization and demonstrate that cholesterol forms submicrometric domains in living cells.
- Published
- 2015
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