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Volumn 8, Issue 1, 2005, Pages 9-17

The chick: A great model system becomes even greater

Author keywords

[No Author keywords available]

Indexed keywords

ACCESS TO INFORMATION; ARTICLE; CHICK EMBRYO; CYTOLOGY; DEVELOPMENTAL BIOLOGY; ELECTROPORATION; EMBRYO; EMBRYO CELL; EMBRYO DEVELOPMENT; GENETICS; IMMUNOLOGY; IN VIVO STUDY; MODEL; NONHUMAN; ONCOLOGY; PRIORITY JOURNAL; PROMOTER REGION; SEQUENCE ANALYSIS; STEM CELL; TRANSGENICS; VIROLOGY;

EID: 11244302359     PISSN: 15345807     EISSN: None     Source Type: Journal    
DOI: 10.1016/S1534-5807(04)00425-3     Document Type: Article
Times cited : (304)

References (64)
  • 1
    • 0014130852 scopus 로고
    • Contact inhibition: The phenomenon and its biological implications
    • Abercrombie M. Contact inhibition: The phenomenon and its biological implications Natl. Cancer Inst. Monogr. 26 1967 249-277
    • (1967) Natl. Cancer Inst. Monogr. , vol.26 , pp. 249-277
    • Abercrombie, M.1
  • 3
    • 0006057765 scopus 로고
    • Studies on the development of the foregut in the chick blastoderm. 1. The presumptive foregut area
    • Bellairs R. Studies on the development of the foregut in the chick blastoderm. 1. The presumptive foregut area J. Embryol. Exp. Morphol. 1 1953 115-124
    • (1953) J. Embryol. Exp. Morphol. , vol.1 , pp. 115-124
    • Bellairs, R.1
  • 5
    • 2442651549 scopus 로고    scopus 로고
    • Functional knockdown of neuropilin-1 in the developing chick nervous system by siRNA hairpins phenocopies genetic ablation in the mouse
    • Bron R. Eickholt B.J. Vermeren M. Fragale N. Cohen J. Functional knockdown of neuropilin-1 in the developing chick nervous system by siRNA hairpins phenocopies genetic ablation in the mouse Dev. Dyn. 230 2004 299-308
    • (2004) Dev. Dyn. , vol.230 , pp. 299-308
    • Bron, R.1    Eickholt, B.J.2    Vermeren, M.3    Fragale, N.4    Cohen, J.5
  • 6
    • 0025936509 scopus 로고
    • Increased ratio of targeted to random integration after transfection of chicken B cell lines
    • Buerstedde J.M. Takeda S. Increased ratio of targeted to random integration after transfection of chicken B cell lines Cell 67 1991 179-188
    • (1991) Cell , vol.67 , pp. 179-188
    • Buerstedde, J.M.1    Takeda, S.2
  • 7
    • 3543110787 scopus 로고    scopus 로고
    • The chicken genome and the developmental biologist
    • Burt D.W. The chicken genome and the developmental biologist Mech. Dev. 121 2004 1129-1135
    • (2004) Mech. Dev. , vol.121 , pp. 1129-1135
    • Burt, D.W.1
  • 8
    • 0027530341 scopus 로고
    • Germline chimeric chickens from dispersed donor blastodermal cells and compromised recipient embryos
    • Carsience R.S. Clark M.E. Verrinder Gibbins A.M. Etches R.J. Germline chimeric chickens from dispersed donor blastodermal cells and compromised recipient embryos Development 117 1993 669-675
    • (1993) Development , vol.117 , pp. 669-675
    • Carsience, R.S.1    Clark, M.E.2    Verrinder Gibbins, A.M.3    Etches, R.J.4
  • 10
    • 3543092063 scopus 로고    scopus 로고
    • From the hemangioblast to self-tolerance: A series of innovations gained from studies on the avian embryo
    • Dieterlen-Lievre F. Le Douarin N.M. From the hemangioblast to self-tolerance: A series of innovations gained from studies on the avian embryo Mech. Dev. 121 2004 1117-1128
    • (2004) Mech. Dev. , vol.121 , pp. 1117-1128
    • Dieterlen-Lievre, F.1    Le Douarin, N.M.2
  • 11
    • 0014323226 scopus 로고
    • Cell adhesion and movement in relation to the developing limb pattern in normal and talpid mutant chick embryos
    • Ede D.A. Agerbak G.S. Cell adhesion and movement in relation to the developing limb pattern in normal and talpid mutant chick embryos J. Embryol. Exp. Morphol. 20 1968 81-100
    • (1968) J. Embryol. Exp. Morphol. , vol.20 , pp. 81-100
    • Ede, D.A.1    Agerbak, G.S.2
  • 12
    • 0025304110 scopus 로고
    • Segmentation in the chick embryo hindbrain is defined by cell lineage restrictions
    • Fraser S. Keynes R. Lumsden A. Segmentation in the chick embryo hindbrain is defined by cell lineage restrictions Nature 344 1990 431-435
    • (1990) Nature , vol.344 , pp. 431-435
    • Fraser, S.1    Keynes, R.2    Lumsden, A.3
  • 13
    • 0001449332 scopus 로고
    • Studies on limb morphogenesis. I. Experiments with the polydactylous mutant, Talpid
    • Goetinck P.F. Studies on limb morphogenesis. I. Experiments with the polydactylous mutant, Talpid J. Exp. Zool. 155 1964 161-170
    • (1964) J. Exp. Zool. , vol.155 , pp. 161-170
    • Goetinck, P.F.1
  • 14
    • 34347163853 scopus 로고
    • Die Primitiventwicklung des Hünchens nach stereokinematographischen Untersuchungen, kontrolliert durch vitale Farbmarkierung und verglichen mit der Entwicklung anderer Wirbeltiere
    • Gräper L. Die Primitiventwicklung des Hünchens nach stereokinematographischen Untersuchungen, kontrolliert durch vitale Farbmarkierung und verglichen mit der Entwicklung anderer Wirbeltiere Arch EntwMech Org 116 1929 382-429
    • (1929) Arch. EntwMech.Org. , vol.116 , pp. 382-429
    • Gräper, L.1
  • 15
    • 1842394395 scopus 로고
    • Radial arrangement of clonally related cells in the chicken optic tectum: Lineage analysis with a recombinant retrovirus
    • Gray G.E. Glover J.C. Majors J. Sanes J.R. Radial arrangement of clonally related cells in the chicken optic tectum: Lineage analysis with a recombinant retrovirus Proc. Natl. Acad. Sci. USA 85 1988 7356-7360
    • (1988) Proc. Natl. Acad. Sci. USA , vol.85 , pp. 7356-7360
    • Gray, G.E.1    Glover, J.C.2    Majors, J.3    Sanes, J.R.4
  • 16
    • 0003407708 scopus 로고
    • Exercitatio anatomica de motu cordis et sanguinis in animalibus
    • Guiliemi (Frankfurt: Fitzeri)
    • Harvey, W. (1628). Exercitatio anatomica de motu cordis et sanguinis in animalibus (Frankfurt: Guiliemi Fitzeri).
    • (1628)
    • Harvey, W.1
  • 17
    • 0006718991 scopus 로고
    • Genetics of the fowl. VI. A tentative chromosome map
    • (Duerst Festschrift)
    • Hutt, F.B. (1936). Genetics of the fowl. VI. A tentative chromosome map. In Neue Forschung für Tierzucht und Abstammung (Duerst Festschrift), pp. 105-112.
    • (1936) Neue Forschung Für Tierzucht und Abstammung , pp. 105-112
    • Hutt, F.B.1
  • 18
    • 33947686952 scopus 로고    scopus 로고
    • Sequencing and comparative analysis of the chicken genome
    • International Chicken Genome Sequencing Consortium
    • International Chicken Genome Sequencing Consortium Sequencing and comparative analysis of the chicken genome Nature 432 2004 695-716
    • (2004) Nature , vol.432 , pp. 695-716
  • 19
    • 10644271562 scopus 로고    scopus 로고
    • A genetic variation map for chicken with 2.8 million single nucleotide polymorphisms
    • International Chicken Polymorphism Map Consortium
    • International Chicken Polymorphism Map Consortium A genetic variation map for chicken with 2.8 million single nucleotide polymorphisms Nature 432 2004 717-722
    • (2004) Nature , vol.432 , pp. 717-722
  • 20
    • 0034303585 scopus 로고    scopus 로고
    • Neuronal specification in the spinal cord: Inductive signals and transcriptional codes
    • Jessell T.M. Neuronal specification in the spinal cord: Inductive signals and transcriptional codes Nat. Rev. Genet. 1 2000 20-29
    • (2000) Nat. Rev. Genet. , vol.1 , pp. 20-29
    • Jessell, T.M.1
  • 21
    • 0021160555 scopus 로고
    • Segmentation in the vertebrate nervous system
    • Keynes R.J. Stern C.D. Segmentation in the vertebrate nervous system Nature 310 1984 786-789
    • (1984) Nature , vol.310 , pp. 786-789
    • Keynes, R.J.1    Stern, C.D.2
  • 22
    • 3543071062 scopus 로고    scopus 로고
    • Somite polarity and segmental patterning of the peripheral nervous system
    • Kuan C.Y. Tannahill D. Cook G.M. Keynes R.J. Somite polarity and segmental patterning of the peripheral nervous system Mech. Dev. 121 2004 1055-1068
    • (2004) Mech. Dev. , vol.121 , pp. 1055-1068
    • Kuan, C.Y.1    Tannahill, D.2    Cook, G.M.3    Keynes, R.J.4
  • 23
    • 0028569704 scopus 로고
    • Sonic hedgehog and Fgf-4 act through a signaling cascade and feedback loop to integrate growth and patterning of the developing limb bud
    • Laufer E. Nelson C.E. Johnson R.L. Morgan B.A. Tabin C. Sonic hedgehog and Fgf-4 act through a signaling cascade and feedback loop to integrate growth and patterning of the developing limb bud Cell 79 1994 993-1003
    • (1994) Cell , vol.79 , pp. 993-1003
    • Laufer, E.1    Nelson, C.E.2    Johnson, R.L.3    Morgan, B.A.4    Tabin, C.5
  • 24
    • 0015539302 scopus 로고
    • A biological cell labeling technique and its use in expermental embryology
    • Le Douarin N. A biological cell labeling technique and its use in expermental embryology Dev. Biol. 30 1973 217-222
    • (1973) Dev. Biol. , vol.30 , pp. 217-222
    • Le Douarin, N.1
  • 25
    • 3543137674 scopus 로고    scopus 로고
    • The avian embryo as a model to study the development of the neural crest: A long and still ongoing story
    • Le Douarin N.M. The avian embryo as a model to study the development of the neural crest: A long and still ongoing story Mech. Dev. 121 2004 1089-1102
    • (2004) Mech. Dev. , vol.121 , pp. 1089-1102
    • Le Douarin, N.M.1
  • 26
    • 0029089617 scopus 로고
    • A molecular pathway determining left-right asymmetry in chick embryogenesis
    • Levin M. Johnson R.L. Stern C.D. Kuehn M. Tabin C. A molecular pathway determining left-right asymmetry in chick embryogenesis Cell 82 1995 803-814
    • (1995) Cell , vol.82 , pp. 803-814
    • Levin, M.1    Johnson, R.L.2    Stern, C.D.3    Kuehn, M.4    Tabin, C.5
  • 27
    • 3543089764 scopus 로고    scopus 로고
    • Segmentation and compartition in the early avian hindbrain
    • Lumsden A. Segmentation and compartition in the early avian hindbrain Mech. Dev. 121 2004 1081-1088
    • (2004) Mech. Dev. , vol.121 , pp. 1081-1088
    • Lumsden, A.1
  • 28
    • 0024548307 scopus 로고
    • Segmental patterns of neuronal development in the chick hindbrain
    • Lumsden A. Keynes R. Segmental patterns of neuronal development in the chick hindbrain Nature 337 1989 424-428
    • (1989) Nature , vol.337 , pp. 424-428
    • Lumsden, A.1    Keynes, R.2
  • 29
    • 0343683581 scopus 로고
    • De formatione pulli in
    • ovo (London: Royal Society)
    • Malpighi, M. (1672). De formatione pulli in ovo (London: Royal Society).
    • (1672)
    • Malpighi, M.1
  • 30
    • 85052038321 scopus 로고
    • Repetitas auctasque de ovo incubato observationes continens
    • (London: Johannis Martyn)
    • Malpighi, M. (1675). Repetitas auctasque de ovo incubato observationes continens (London: Johannis Martyn)
    • (1675)
    • Malpighi, M.1
  • 32
    • 2942607379 scopus 로고    scopus 로고
    • Events that led to the discovery of T-cell development and function-a personal recollection
    • Miller J.F. Events that led to the discovery of T-cell development and function-a personal recollection Tissue Antigens 63 2004 509-517
    • (2004) Tissue Antigens , vol.63 , pp. 509-517
    • Miller, J.F.1
  • 33
    • 0026780670 scopus 로고
    • Targeted misexpression of Hox-4.6 in the avian limb bud causes apparent homeotic transformations
    • Morgan B.A. Izpisua-Belmonte J.C. Duboule D. Tabin C.J. Targeted misexpression of Hox-4.6 in the avian limb bud causes apparent homeotic transformations Nature 358 1992 236-239
    • (1992) Nature , vol.358 , pp. 236-239
    • Morgan, B.A.1    Izpisua-Belmonte, J.C.2    Duboule, D.3    Tabin, C.J.4
  • 34
    • 0031566158 scopus 로고    scopus 로고
    • Comparison of three nonviral transfection methods for foreign gene expression in early chicken embryos in ovo
    • Muramatsu T. Mizutani Y. Ohmori Y. Okumura J. Comparison of three nonviral transfection methods for foreign gene expression in early chicken embryos in ovo Biochem. Biophys. Res. Commun. 230 1997 376-380
    • (1997) Biochem. Biophys. Res. Commun. , vol.230 , pp. 376-380
    • Muramatsu, T.1    Mizutani, Y.2    Ohmori, Y.3    Okumura, J.4
  • 37
    • 0030840351 scopus 로고    scopus 로고
    • Avian hairy gene expression identifies a molecular clock linked to vertebrate segmentation and somitogenesis
    • Palmeirim I. Henrique D. Ish-Horowicz D. Pourquie O. Avian hairy gene expression identifies a molecular clock linked to vertebrate segmentation and somitogenesis Cell 91 1997 639-648
    • (1997) Cell , vol.91 , pp. 639-648
    • Palmeirim, I.1    Henrique, D.2    Ish-Horowicz, D.3    Pourquie, O.4
  • 38
    • 8244228416 scopus 로고
    • Beiträge zur Entwickelungseschichte des Hünchens im Ei
    • Würzburg: Brönner
    • Pander C. Beiträge zur Entwickelungseschichte des Hünchens im Ei 1817 Brönner Würzburg
    • (1817)
    • Pander, C.1
  • 39
    • 3543110789 scopus 로고    scopus 로고
    • Avian pluripotent stem cells
    • Petitte J.N. Liu G. Yang Z. Avian pluripotent stem cells Mech. Dev. 121 2004 1159-1168
    • (2004) Mech. Dev. , vol.121 , pp. 1159-1168
    • Petitte, J.N.1    Liu, G.2    Yang, Z.3
  • 40
    • 3543138873 scopus 로고    scopus 로고
    • The chick embryo: A leading model in somitogenesis studies
    • Pourquie O. The chick embryo: A leading model in somitogenesis studies Mech. Dev. 121 2004 1069-1079
    • (2004) Mech. Dev. , vol.121 , pp. 1069-1079
    • Pourquie, O.1
  • 41
    • 3543050006 scopus 로고    scopus 로고
    • The generation and diversification of spinal motor neurons: Signals and responses
    • Price S.R. Briscoe J. The generation and diversification of spinal motor neurons: Signals and responses Mech. Dev. 121 2004 1103-1115
    • (2004) Mech. Dev. , vol.121 , pp. 1103-1115
    • Price, S.R.1    Briscoe, J.2
  • 42
    • 3543083929 scopus 로고    scopus 로고
    • Unveiling the establishment of left-right asymmetry in the chick embryo
    • Raya A. Izpisua Belmonte J.C. Unveiling the establishment of left-right asymmetry in the chick embryo Mech. Dev. 121 2004 1043-1054
    • (2004) Mech. Dev. , vol.121 , pp. 1043-1054
    • Raya, A.1    Izpisua Belmonte, J.C.2
  • 43
    • 0027760995 scopus 로고
    • Sonic hedgehog mediates the polarizing activity of the ZPA
    • Riddle R.D. Johnson R.L. Laufer E. Tabin C. Sonic hedgehog mediates the polarizing activity of the ZPA Cell 75 1993 1401-1416
    • (1993) Cell , vol.75 , pp. 1401-1416
    • Riddle, R.D.1    Johnson, R.L.2    Laufer, E.3    Tabin, C.4
  • 44
    • 84979948588 scopus 로고
    • A sarcoma of the fowl transmissible by an agent separable from the tumor
    • Rous P. A sarcoma of the fowl transmissible by an agent separable from the tumor J. Exp. Med. 13 1911 397-411
    • (1911) J. Exp. Med. , vol.13 , pp. 397-411
    • Rous, P.1
  • 45
    • 3543055751 scopus 로고    scopus 로고
    • Prospects for transgenesis in the chick
    • Sang H. Prospects for transgenesis in the chick Mech. Dev. 121 2004 1179-1186
    • (2004) Mech. Dev. , vol.121 , pp. 1179-1186
    • Sang, H.1
  • 46
    • 84924843883 scopus 로고
    • The proximo-distal sequence of origin of parts of the chick wing and the role of the ectoderm
    • Saunders J.W.J. The proximo-distal sequence of origin of parts of the chick wing and the role of the ectoderm J. Exp. Zool. 108 1948 363-404
    • (1948) J. Exp. Zool. , vol.108 , pp. 363-404
    • Saunders, J.W.J.1
  • 47
    • 0002886715 scopus 로고
    • Ectodermal-mesenchymal interactions in the origin of limb symmetry
    • R. Fleischmeyer, & R. E. Billingham (Eds.), Baltimore: Williams - Wilkins
    • Saunders J.W.J. Gasseling M.T. Ectodermal-mesenchymal interactions in the origin of limb symmetry Fleischmeyer R. Billingham R.E. Epithelial-Mesenchymal Interactions 1968 78-97 Williams - Wilkins Baltimore
    • (1968) Epithelial-Mesenchymal Interactions , pp. 78-97
    • Saunders, J.W.J.1    Gasseling, M.T.2
  • 48
    • 0344256726 scopus 로고    scopus 로고
    • Churchill, a zinc finger transcriptional activator, regulates the transition between gastrulation and neurulation
    • Sheng G. dos Reis M. Stern C.D. Churchill, a zinc finger transcriptional activator, regulates the transition between gastrulation and neurulation Cell 115 2003 603-613
    • (2003) Cell , vol.115 , pp. 603-613
    • Sheng, G.1    dos Reis, M.2    Stern, C.D.3
  • 49
    • 0017250977 scopus 로고
    • DNA related to the transforming gene(s) of avian sarcoma viruses is present in normal avian DNA
    • Stehelin D. Varmus H.E. Bishop J.M. Vogt P.K. DNA related to the transforming gene(s) of avian sarcoma viruses is present in normal avian DNA Nature 260 1976 170-173
    • (1976) Nature , vol.260 , pp. 170-173
    • Stehelin, D.1    Varmus, H.E.2    Bishop, J.M.3    Vogt, P.K.4
  • 50
    • 0034056969 scopus 로고    scopus 로고
    • Conrad H. Waddington's contributions to avian and mammalian development, 1930-1940
    • Stern C.D. Conrad H. Waddington's contributions to avian and mammalian development, 1930-1940 Int. J. Dev. Biol. 44 2000 15-22
    • (2000) Int. J. Dev. Biol. , vol.44 , pp. 15-22
    • Stern, C.D.1
  • 51
    • 3543144805 scopus 로고    scopus 로고
    • The chick embryo-past, present and future as a model system in developmental biology
    • Stern C.D. The chick embryo-past, present and future as a model system in developmental biology Mech. Dev. 121 2004 1011-1013
    • (2004) Mech. Dev. , vol.121 , pp. 1011-1013
    • Stern, C.D.1
  • 52
    • 0020974161 scopus 로고
    • The effect of local application of retinoic acid to the anterior margin of the developing chick limb
    • Summerbell D. The effect of local application of retinoic acid to the anterior margin of the developing chick limb J. Embryol. Exp. Morphol. 78 1983 269-289
    • (1983) J. Embryol. Exp. Morphol. , vol.78 , pp. 269-289
    • Summerbell, D.1
  • 53
    • 0009849774 scopus 로고
    • Homology between RNA from Rous Sarcoma Virus and DNA from Rous Sarcoma Virus-infected cells
    • Temin H.M. Homology between RNA from Rous Sarcoma Virus and DNA from Rous Sarcoma Virus-infected cells Proc. Natl. Acad. Sci. USA 52 1964 323-329
    • (1964) Proc. Natl. Acad. Sci. USA , vol.52 , pp. 323-329
    • Temin, H.M.1
  • 54
    • 0014964695 scopus 로고
    • RNA-dependent DNA polymerase in virions of Rous Sarcoma Virus
    • Temin H.M. Mizutani S. RNA-dependent DNA polymerase in virions of Rous Sarcoma Virus Nature 226 1970 1211-1213
    • (1970) Nature , vol.226 , pp. 1211-1213
    • Temin, H.M.1    Mizutani, S.2
  • 55
    • 3543117773 scopus 로고    scopus 로고
    • The contribution of chicken embryology to the understanding of vertebrate limb development
    • Tickle C. The contribution of chicken embryology to the understanding of vertebrate limb development Mech. Dev. 121 2004 1019-1029
    • (2004) Mech. Dev. , vol.121 , pp. 1019-1029
    • Tickle, C.1
  • 56
    • 0037389626 scopus 로고    scopus 로고
    • Functional analysis of chicken Sox2 enhancers highlights an array of diverse regulatory elements that are conserved in mammals
    • Uchikawa M. Ishida Y. Takemoto T. Kamachi Y. Kondoh H. Functional analysis of chicken Sox2 enhancers highlights an array of diverse regulatory elements that are conserved in mammals Dev. Cell 4 2003 509-519
    • (2003) Dev. Cell , vol.4 , pp. 509-519
    • Uchikawa, M.1    Ishida, Y.2    Takemoto, T.3    Kamachi, Y.4    Kondoh, H.5
  • 57
    • 3543060533 scopus 로고    scopus 로고
    • Efficient identification of regulatory sequences in the chicken genome by a powerful combination of embryo electroporation and genome comparison
    • Uchikawa M. Takemoto T. Kamachi Y. Kondoh H. Efficient identification of regulatory sequences in the chicken genome by a powerful combination of embryo electroporation and genome comparison Mech. Dev. 121 2004 1145-1158
    • (2004) Mech. Dev. , vol.121 , pp. 1145-1158
    • Uchikawa, M.1    Takemoto, T.2    Kamachi, Y.3    Kondoh, H.4
  • 59
    • 0003604438 scopus 로고
    • Über Entwickelungsgeschichte der Thiere. Beobachtung und Reflexion
    • Königsberg: Bornträger
    • von Baer K.E. Über Entwickelungsgeschichte der Thiere. Beobachtung und Reflexion 1828 Bornträger Königsberg
    • (1828)
    • von Baer, K.E.1
  • 61
    • 3543080406 scopus 로고    scopus 로고
    • Much more from the chicken's egg than breakfast-a wonderful model system
    • Wolpert L. Much more from the chicken's egg than breakfast-a wonderful model system Mech. Dev. 121 2004 1015-1017
    • (2004) Mech. Dev. , vol.121 , pp. 1015-1017
    • Wolpert, L.1
  • 62
    • 0036138437 scopus 로고    scopus 로고
    • No evidence for ventrally migrating neural tube cells from the mid- and hindbrain
    • Yaneza M. Gilthorpe J.D. Lumsden A. Tucker A.S. No evidence for ventrally migrating neural tube cells from the mid- and hindbrain Dev. Dyn. 223 2002 163-167
    • (2002) Dev. Dyn. , vol.223 , pp. 163-167
    • Yaneza, M.1    Gilthorpe, J.D.2    Lumsden, A.3    Tucker, A.S.4
  • 64
    • 84981833850 scopus 로고
    • Interaction between limb bud ectoderm and mesoderm in the chick embryo. III. Experiments with polydactylous limbs
    • Zwilling E. Hansborough L. Interaction between limb bud ectoderm and mesoderm in the chick embryo. III. Experiments with polydactylous limbs J. Exp. Zool. 132 1956 219-239
    • (1956) J. Exp. Zool. , vol.132 , pp. 219-239
    • Zwilling, E.1    Hansborough, L.2


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