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Volumn 61, Issue 20, 2006, Pages

The long-term succession of cladoceran fauna and palaeoclimate forcing: A 14,600Ȕyear record from Plešné Lake, the Bohemian Forest

Author keywords

Bohemian Forest; Cladocera; climate change; lake sediment; palaeolimnology; Plesne Lake

Indexed keywords


EID: 85026124109     PISSN: 00063088     EISSN: 13369563     Source Type: Journal    
DOI: 10.2478/s11756-007-0072-x     Document Type: Article
Times cited : (22)

References (61)
  • 1
    • 0022827546 scopus 로고
    • Holocene lacustrine microfossils and environmental changes
    • Alhonen, P. 1986. Holocene lacustrine microfossils and environmental changes. Bull. Geol. Soc. Finland 58: 57-69.
    • (1986) Bull. Geol. Soc. Finland , vol.58 , pp. 57-69
    • Alhonen, P.1
  • 2
    • 0024527782 scopus 로고
    • Late-Glacial radiocarbon-and palynostratigraphy on the Swiss Plateau
    • Ammann, B. & Lotter, A.F. 1989. Late-Glacial radiocarbon-and palynostratigraphy on the Swiss Plateau. Boreas 18: 109-126
    • (1989) Boreas , vol.18 , pp. 109-126
    • Ammann, B.1    Lotter, A.F.2
  • 4
    • 14944344622 scopus 로고    scopus 로고
    • Late Glacial and early Holocene palaeoclimatic reconstruction based on glacier fluctuations and equlibrium-line altitudes at northern Folgefonna, Hardanger, western Norway
    • Bakke, J., Dahl, S.O. & Nesje, A. 2005. Late Glacial and early Holocene palaeoclimatic reconstruction based on glacier fluctuations and equlibrium-line altitudes at northern Folgefonna, Hardanger, western Norway. j. Quater. Sci. 20: 179-198.
    • (2005) j. Quater. Sci. , vol.20 , pp. 179-198
    • Bakke, J.1    Dahl, S.O.2    Nesje, A.3
  • 5
  • 6
    • 0001660151 scopus 로고
    • The Cladocera of Ontario with remarks on some species and distribution
    • Brandlová, J., Brandl, Z. & Fernando, C.H. 1972. The Cladocera of Ontario with remarks on some species and distribution. Can. j. Zool. 50: 1373-1403.
    • (1972) Can. j. Zool. , vol.50 , pp. 1373-1403
    • Brandlová, J.1    Brandl, Z.2    Fernando, C.H.3
  • 7
    • 51249192656 scopus 로고
    • Verarmung des Planktons in kleinen Seen durch Heterocope
    • Burkhardt, G. 1944. Verarmung des Planktons in kleinen Seen durch Heterocope. z. Hydrol. 10: 121-124.
    • (1944) z. Hydrol. , vol.10 , pp. 121-124
    • Burkhardt, G.1
  • 9
    • 85026091101 scopus 로고
    • Beiträge zur Biologie des Plöckensteinsees im Bömerwalde. 5. Jahresbericht der k.k. Staatsrealschule im XVI
    • Černy, A. 1910. Beiträge zur Biologie des Plöckensteinsees im Bömerwalde. 5. Jahresbericht der k.k. Staatsrealschule im XVI. Bezirke in Wien, pp. 5-22.
    • (1910) Bezirke in Wien , pp. 5-22
    • Černy, A.1
  • 10
    • 0032837419 scopus 로고    scopus 로고
    • Intercontinental allozyme differentiation among four holarctic Daphnia species
    • černý, M. & Hebert, P.D.N. 1999. Intercontinental allozyme differentiation among four holarctic Daphnia species. Limnol. Oceanogr. 44: 1381-1387.
    • (1999) Limnol. Oceanogr. , vol.44 , pp. 1381-1387
    • černý, M.1    Hebert, P.D.N.2
  • 11
    • 0036139321 scopus 로고    scopus 로고
    • Timing, equlibrium-line altitudes and climatic implications of two early-Holocene glacier read vanees during the Erdalen Event at Jostedalsbreen
    • Dahl, S.O., Nesje, A., Lie, O., Fjordheim, к. & Matthews, J.A. 2002. Timing, equlibrium-line altitudes and climatic implications of two early-Holocene glacier read vanees during the Erdalen Event at Jostedalsbreen, western Norway. Holocene 12: 17-25.
    • (2002) , vol.12 , pp. 17-25
    • Dahl, S.O.1    Nesje, A.2    Lie, O.3    Fjordheim, к.4    Matthews, J.A.5
  • 12
    • 0010912495 scopus 로고
    • Die Geschichte der Cladocerenfauna des Barsch-Sees, eines sauren, kalkarmen Moorweihers im mitteleuropäischen Flachland
    • FlÖssner, D. 1990. Die Geschichte der Cladocerenfauna des Barsch-Sees, eines sauren, kalkarmen Moorweihers im mitteleuropäischen Flachland. Limnologica 21: 125-135.
    • (1990) Limnologica , vol.21 , pp. 125-135
    • FlÖssner, D.1
  • 13
    • 3542993136 scopus 로고    scopus 로고
    • Die Haplopoda und Cladocera Mitteleuropas
    • Publishers
    • FLÖSSNER, D. 2000. Die Haplopoda und Cladocera Mitteleuropas. Backhuys Publishers, Leiden, 428 pp.
    • (2000) Backhuys
    • FLÖSSNER, D.1
  • 14
    • 0346404399 scopus 로고
    • Evidence for eutrophication from remains of organisms in sediments
    • National Academy of Sciences
    • Frey, D.G. 1969. Evidence for eutrophication from remains of organisms in sediments, pp. 594-613. In: Eutrophication: causes, consequences, correctives, Proceedings of a symposium, National Academy of Sciences, Washington, D.c.
    • (1969) Eutrophication: causes, consequences, correctives, Proceedings of a symposium , pp. 594-613
    • Frey, D.G.1
  • 18
    • 0000483770 scopus 로고
    • Developmental history of the Grösser Plöner See and Schöhsee (north Germany): cladoceran analysis, with special reference to eutrophication
    • Hofmann, W. 1986. Developmental history of the Grösser Plöner See and Schöhsee (north Germany): cladoceran analysis, with special reference to eutrophication. Arch. Hydrobiol. Suppl. 74: 259-287.
    • (1986) Arch. Hydrobiol. , pp. 259-287
    • Hofmann, W.1
  • 19
    • 51249178498 scopus 로고
    • Cladocera in space and time- analysis of lake sediments
    • Hofmann, W. 1987. Cladocera in space and time- analysis of lake sediments. Hydrobiologia 145: 315-321.
    • (1987) Hydrobiologia , vol.145 , pp. 315-321
    • Hofmann, W.1
  • 20
    • 0031971850 scopus 로고    scopus 로고
    • Cladocerans and chironomids as indicators of lake level changes in north temperature lakes
    • Hofmann, W. 1998. Cladocerans and chironomids as indicators of lake level changes in north temperature lakes. j. Paleolimnol. 19: 55-62.
    • (1998) j. Paleolimnol. , vol.19 , pp. 55-62
    • Hofmann, W.1
  • 21
    • 0034660214 scopus 로고    scopus 로고
    • Response of the chydorid faunas to rapid climatic changes in four alpine lakes at different altitudes Palaeogeogr
    • Hofmann, W. 2000. Response of the chydorid faunas to rapid climatic changes in four alpine lakes at different altitudes Palaeogeogr. Palaeoclimatol. Palaeoecol. 159: 281-292.
    • (2000) Palaeoclimatol. Palaeoecol. , vol.159 , pp. 281-292
    • Hofmann, W.1
  • 22
    • 35548953313 scopus 로고    scopus 로고
    • Acidification and the structure of crustacean zooplankton in mountain lakes: The Tatra Mountains (Slovakia, Poland)
    • Hořická, Z., Stuchlík, е., Hudec, I., černý, M. & Fott, J. 2006. Acidification and the structure of crustacean zooplankton in mountain lakes: The Tatra Mountains (Slovakia, Poland). Biologia, Bratislava 61, Suppl. 18: S121-S134.
    • (2006) Biologia, Bratislava , vol.61 , pp. S121-S134
    • Hořická, Z.1    Stuchlík, е.2    Hudec, I.3    černý, M.4    Fott, J.5
  • 23
    • 85026043633 scopus 로고
    • Zooplankton a význační zástupcovia niektorých skupín drobného vodného živočíŠstva tatranských plies. [Zooplankton and significant representatives of some groups of small water animals in Tatra lakes]
    • HrbáCek, J., Brtek, J., Vranovský, M. & Štěrba, о. 1974. Zooplankton a význační zástupcovia niektorých skupín drobného vodného živočíŠstva tatranských plies. [Zooplankton and significant representatives of some groups of small water animals in Tatra lakes]. Zborník TANAP 16: 105-109.
    • (1974) Zborník TANAP , vol.16 , pp. 105-109
    • HrbáCek, J.1    Brtek, J.2    Vranovský, M.3    Štěrba, о.4
  • 24
    • 0033500089 scopus 로고    scopus 로고
    • Reconstruction and modelling Late Weichselian climates: the Younger Dryas in Europe as a case study
    • Isarin, R.F.B. & Renssen, H. 1999. Reconstruction and modelling Late Weichselian climates: the Younger Dryas in Europe as a case study. Earth Sei. Rev. 48: 1-38.
    • (1999) Earth Sei. Rev. , vol.48 , pp. 1-38
    • Isarin, R.F.B.1    Renssen, H.2
  • 25
    • 85026087234 scopus 로고    scopus 로고
    • Late Glacial and Holocene history of Plešné Lake and its surrounding landscape based on pollen and palaeoalgological analyses
    • Jankovská, V. 2006. Late Glacial and Holocene history of Plešné Lake and its surrounding landscape based on pollen and palaeoalgological analyses. Biologia, Bratislava 61, Suppl. 20: S371-S385.
    • (2006) Biologia, Bratislava , vol.61 , pp. S371-S385
    • Jankovská, V.1
  • 26
    • 36049016789 scopus 로고    scopus 로고
    • New bathymétrie mapping of the Bohemian Forest glacial lakes
    • Janský, в., Sobr, M., Ёорим, J. & Gesák, J. 2005. New bathymétrie mapping of the Bohemian Forest glacial lakes. Geografie, Sbor. Čgs 110: 176-187.
    • (2005) Geografie, Sbor. Čgs , vol.110 , pp. 176-187
    • Janský, в.1    Sobr, M.2    Gesák, J.3
  • 27
    • 0342601512 scopus 로고    scopus 로고
    • The acidification of the Herrenwiesser See, Black Forest, Germany, before and during industrialization
    • Jüttner, I., Lintelmann, J., Michalke, в., Winkler, R., Steinberg, р.е. & Kettrup, а. 1997. The acidification of the Herrenwiesser See, Black Forest, Germany, before and during industrialization. Water Res. 31: 1194-1206.
    • (1997) Water Res. , vol.31 , pp. 1194-1206
    • Jüttner, I.1    Lintelmann, J.2    Michalke, в.3    Winkler, R.4    Steinberg, р.е.5    Kettrup, а.6
  • 28
    • 0031826444 scopus 로고    scopus 로고
    • The effect of plants on mineral weathering
    • Kelly, E.F., Chadwick, O.A. & Hill, C.A. 1998. The effect of plants on mineral weathering. Biogeochem. 42: 21-43.
    • (1998) Biogeochem. , vol.42 , pp. 21-43
    • Kelly, E.F.1    Chadwick, O.A.2    Hill, C.A.3
  • 29
    • 77950339138 scopus 로고    scopus 로고
    • Restoration of zooplankton in a small acidified mountain lake (Plešné Lake, Bohemian Forest) by reintroduction of key species
    • Kohout, L. & Fott, J. 2006. Restoration of zooplankton in a small acidified mountain lake (Plešné Lake, Bohemian Forest) by reintroduction of key species. Biologia, Bratislava 61, Suppl. 20: 477-483.
    • (2006) Biologia, Bratislava , vol.61 , pp. 477-483
    • Kohout, L.1    Fott, J.2
  • 31
    • 17344363975 scopus 로고    scopus 로고
    • Sulfur and nitrogen emissions in the Czech Republic and Slovakia from 1850 till 2000
    • Kopáček, J. & Veselý, J. 2005. Sulfur and nitrogen emissions in the Czech Republic and Slovakia from 1850 till 2000. Atmos. Environ. 39: 2179-2188.
    • (2005) Atmos. Environ. , vol.39 , pp. 2179-2188
    • Kopáček, J.1    Veselý, J.2
  • 32
    • 0000656448 scopus 로고
    • Cladoceran remains as indicators of lake acidification
    • Krause-Dellin, D. & Steinberg, C. 1986. Cladoceran remains as indicators of lake acidification. Hydrobiologia 143: 129-134.
    • (1986) Hydrobiologia , vol.143 , pp. 129-134
    • Krause-Dellin, D.1    Steinberg, C.2
  • 33
    • 0034660170 scopus 로고    scopus 로고
    • Younger Dryas and Allerød summer temperature at Grezensee (Switzerland) inferred from fossil pollen and cladoceran assemblages
    • Lotter, A.F., Birks, H.J.B., Eicher, U., Hofmann, W., Schwander, J. & Wick, L. 2000. Younger Dryas and Allerød summer temperature at Grezensee (Switzerland) inferred from fossil pollen and cladoceran assemblages. Palaeogeogr. Palaeoclim. Palaeoecol. 159: 349-361.
    • (2000) Palaeogeogr. Palaeoclim. Palaeoecol. , vol.159 , pp. 349-361
    • Lotter, A.F.1    Birks, H.J.B.2    Eicher, U.3    Hofmann, W.4    Schwander, J.5    Wick, L.6
  • 34
    • 1142293855 scopus 로고    scopus 로고
    • Modelling reversibility of central european mountain lakes from acidification: Part I the Bohemian Forest
    • Majer, V., Cosby, B.J., Kopáček, J. & Veselý, J. 2003. Modelling reversibility of central european mountain lakes from acidification: Part I the Bohemian Forest. Hydrol. Earth System Sci. 7: 494-509.
    • (2003) Hydrol. Earth System Sci. , vol.7 , pp. 494-509
    • Majer, V.1    Cosby, B.J.2    Kopáček, J.3    Veselý, J.4
  • 38
    • 0025524511 scopus 로고
    • Recent lake acidification and cladoceran dynamics: surface sediment and core analyses from lake Norway, Scotland and Sweden
    • Nilssen, J.P. & Sandøy, S. 1990. Recent lake acidification and cladoceran dynamics: surface sediment and core analyses from lake Norway, Scotland and Sweden. Philos. Trans. R. Soc. Б. 327: 299-309.
    • (1990) Philos. Trans. R. Soc. Б. , vol.327 , pp. 299-309
    • Nilssen, J.P.1    Sandøy, S.2
  • 39
    • 0041823469 scopus 로고    scopus 로고
    • Ecological distribution of pelagic copepods and species relationship to acidification, liming and natural recovery in a boreal area
    • Nilssen, J.P. & WærvåGEN, S.B. 2003. Ecological distribution of pelagic copepods and species relationship to acidification, liming and natural recovery in a boreal area. j. Limnol. 62: 97-114.
    • (2003) j. Limnol. , vol.62 , pp. 97-114
    • Nilssen, J.P.1    WærvåGEN, S.B.2
  • 40
    • 0036236424 scopus 로고    scopus 로고
    • A high-resolution record of Late-Glacial and Early-Holocene climatic and environmental change in the Czech Republic
    • Pokorný, P. 2002. A high-resolution record of Late-Glacial and Early-Holocene climatic and environmental change in the Czech Republic. Quat. Int. 91: 101-122.
    • (2002) Quat. Int. , vol.91 , pp. 101-122
    • Pokorný, P.1
  • 41
    • 0028570886 scopus 로고
    • Zooplankton decline in the Cerné lake (Sumava mountaines, Bohemia) as reflected in the stratification of cladoceran remains in the sediment
    • Pražáková, M. & отт, J. 1994. Zooplankton decline in the Cerné lake (Sumava mountaines, Bohemia) as reflected in the stratification of cladoceran remains in the sediment. Hydrobiologia 274: 121-126.
    • (1994) Hydrobiologia , vol.274 , pp. 121-126
    • Pražáková, M.1
  • 42
    • 0026481935 scopus 로고
    • Climate driven pH control of remote alpine lakes and effects of acid deposition
    • Psenner, R. & Schmidt, R. 1992. Climate driven pH control of remote alpine lakes and effects of acid deposition. Nature 356: 781-783.
    • (1992) Nature , vol.356 , pp. 781-783
    • Psenner, R.1    Schmidt, R.2
  • 44
    • 0034824636 scopus 로고    scopus 로고
    • The two major warming phases of the last déglaciation at 14.7 and 11.5 ka cal
    • Springer Verlag
    • Renssen, H. & Isarin, R.F.B. 2001. The two major warming phases of the last déglaciation at 14.7 and 11.5 ka cal. BP in Europe: climate reconstructions and AGCM experiments. Global Planet Change 30: 117-153. Sarvala, j. & Halsinaho, s. 1990. Crustacean zooplankton in Finnish forest lakes in relation to acidity and other environmental factors, pp. 1009-1027. In: Kauppi, p., Anttila, p. & Kenttämies, k. (eds) Acidification in Finland, Springer Verlag, Berlin, Heidelberg.
    • (2001) BP in Europe: climate reconstructions and AGCM experiments. Global Planet Change , vol.30 , pp. 117-153
    • Renssen, H.1    Isarin, R.F.B.2
  • 46
    • 0033615503 scopus 로고    scopus 로고
    • Abrupt climate change at the end of the Last Glacial period inferred from trapped air in polar ice
    • Severinghaus, J.P. & Brook, E.J. 1999. Abrupt climate change at the end of the Last Glacial period inferred from trapped air in polar ice. Science 286: 930-934.
    • (1999) Science , vol.286 , pp. 930-934
    • Severinghaus, J.P.1    Brook, E.J.2
  • 47
    • 0021689464 scopus 로고
    • Versauerung des Grossen Arbersee, dokumentiert durch paläolimnologische Untersuchungen
    • Steinberg, C., Meier, R., Emeis-Schwarz, H., Krause-Dellin, D. & Arzet, к. 1984. Versauerung des Grossen Arbersee, dokumentiert durch paläolimnologische Untersuchungen. Vom Wasser 63: 36-56.
    • (1984) Vom Wasser , vol.63 , pp. 36-56
    • Steinberg, C.1    Meier, R.2    Emeis-Schwarz, H.3    Krause-Dellin, D.4    Arzet, к.5
  • 48
    • 0024181319 scopus 로고
    • Paleoindication of acidification in Kleiner Arbersee (Federal Republic of Germany, Bavarian Forest) by chydorids, chrysophytes, and diatoms
    • Steinberg, C., Hartmann, H., Arzet, K. & Krause-Dellin, D. 1988. Paleoindication of acidification in Kleiner Arbersee (Federal Republic of Germany, Bavarian Forest) by chydorids, chrysophytes, and diatoms. j. Paleolimnol. 1: 149-157.
    • (1988) j. Paleolimnol. , pp. 149-157
    • Steinberg, C.1    Hartmann, H.2    Arzet, K.3    Krause-Dellin, D.4
  • 49
    • 0021689464 scopus 로고
    • Versauerung des Grossen Arbersee, dokumentiert durch paläolimnologische Untersuchungen
    • Steinberg, C., Meier, R., Emeis-Schwarz, H., Krause-Dellin, D. & Arzet, к. 1984. Versauerung des Grossen Arbersee, dokumentiert durch paläolimnologische Untersuchungen. Vom Wasser 63: 36-56.
    • (1984) Vom Wasser , vol.63 , pp. 36-56
    • Steinberg, C.1    Meier, R.2    Emeis-Schwarz, H.3    Krause-Dellin, D.4    Arzet, к.5
  • 50
    • 0031391160 scopus 로고    scopus 로고
    • Is here evidence for solar forcing of climate in the GISP2 oxygen isotope record?
    • Stuiver, M., Braziunas, T.F., Grootes, P.M. & Zieliński, G.Α. 1997. Is here evidence for solar forcing of climate in the GISP2 oxygen isotope record? Quat. Res. 48: 259-266.
    • (1997) Quat. Res. , vol.48 , pp. 259-266
    • Stuiver, M.1    Braziunas, T.F.2    Grootes, P.M.3    Zieliński, G.Α.4
  • 51
    • 18544411631 scopus 로고    scopus 로고
    • Palaeolimnological investigations in Poland based on Cladocera (Crustacea)
    • Szeroczyńska, к. 1998. Palaeolimnological investigations in Poland based on Cladocera (Crustacea). Palaeogeog. Palaeo-climat. Palaeoecol. 140: 335-345.
    • (1998) Palaeogeog. Palaeo-climat. Palaeoecol. , vol.140 , pp. 335-345
    • Szeroczyńska, к.1
  • 52
    • 67349220493 scopus 로고    scopus 로고
    • Holocene subfossil chironomid stratigraphy (Diptera: Chironomidae) in the sediment of Plešné Lake (the Bohemian Forest, Czech Republie): Palaeoenvironmental implications
    • TÁtosová, J., Veselý, J. & Stuchlík, е. 2006. Holocene subfossil chironomid stratigraphy (Diptera: Chironomidae) in the sediment of Plešné Lake (the Bohemian Forest, Czech Republie): Palaeoenvironmental implications. Biologia, Bratislava 61, Suppl. 20: S401-S411.
    • (2006) Biologia, Bratislava , vol.61 , pp. S401-S411
    • TÁtosová, J.1    Veselý, J.2    Stuchlík, е.3
  • 53
    • 0001415292 scopus 로고
    • Investigation of the nature of the Sumava lakes: a review
    • Veselý, J. 1994. Investigation of the nature of the Sumava lakes: a review. Čas. Nâr. Muz., řada Přír. 163: 103-120.
    • (1994) Čas. Nâr. Muz., řada Přír. , vol.163 , pp. 103-120
    • Veselý, J.1
  • 54
    • 0008917823 scopus 로고    scopus 로고
    • Changes in vegetation of the Cerné lake area inferred from pollen analysis of lake sediment: period between 3400 БС and 1600 AD
    • Veselý, J. 1998. Changes in vegetation of the Cerné lake area inferred from pollen analysis of lake sediment: period between 3400 БС and 1600 AD. Silva Gabreta 2: 141-153.
    • (1998) Silva Gabreta , vol.2 , pp. 141-153
    • Veselý, J.1
  • 55
    • 0000258676 scopus 로고    scopus 로고
    • The history of metal recorded in the sediments of Bohemian Forest lakes: Since the Bronze Age to the present
    • Veselý, J. 2000. The history of metal recorded in the sediments of Bohemian Forest lakes: Since the Bronze Age to the present. Silva Gabreta 4: 147-165.
    • (2000) Silva Gabreta , vol.4 , pp. 147-165
    • Veselý, J.1
  • 57
    • 0032400362 scopus 로고    scopus 로고
    • Trends in water chemistry of acidified Bohemian lakes from 1984 to 1995: II. Trace elements and aluminum
    • Veselý, J., Hruška, J. & Norton, S.A. 1998. Trends in water chemistry of acidified Bohemian lakes from 1984 to 1995: II. Trace elements and aluminum. Water Air Soil Pollut. 108: 425-443.
    • (1998) Water Air Soil Pollut , vol.108 , pp. 425-443
    • Veselý, J.1    Hruška, J.2    Norton, S.A.3
  • 58
    • 0029663619 scopus 로고    scopus 로고
    • The effect of pH and atmospheric deposition on concentrations of trace elements in a acidified freshwaters: A statistical approach
    • Veselý, J. & Majer, V. 1996. The effect of pH and atmospheric deposition on concentrations of trace elements in a acidified freshwaters: A statistical approach. Water Air Soil Pollut. 88: 227-246.
    • (1996) Water Air Soil Pollut. , vol.88 , pp. 227-246
    • Veselý, J.1    Majer, V.2
  • 60
    • 0041555844 scopus 로고    scopus 로고
    • Major changes in pelagic rotifers during natural and forced recovery from acidification
    • Wærvågen, S.B. & Nilssen, J.P. 2003. Major changes in pelagic rotifers during natural and forced recovery from acidification. Hydrobiologia 499: 63-82.
    • (2003) Hydrobiologia , vol.499 , pp. 63-82
    • Wærvågen, S.B.1    Nilssen, J.P.2
  • 61
    • 84879890448 scopus 로고    scopus 로고
    • Climate modulates the acidity of Arctic lakes on millennial time scales
    • Wolfe, A.P. 2002. Climate modulates the acidity of Arctic lakes on millennial time scales. Geology 30: 215-218.
    • (2002) Geology , vol.30 , pp. 215-218
    • Wolfe, A.P.1


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