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41.
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J R Miller 《Canadian journal of genetics and cytology》1975,17(3):305-309
Although advances in medical genetics are designed ultimately to help human beings receive better health care, they pose many problems for society. Some of these concerns are real, but others result from misunderstanding and/or misrepresentation of the true implication of certain developments in genetics. It is obvious that the geneticist must play a dual role in society as scientist and as advocate. Although such a duality or role is not easy, it is not impossible. However, it does mean that the training of the medical geneticist must include more than exposure to the scientific approach. 相似文献
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David Zamparo Daniel R. Brooks Eric P. Hoberg Deborah A. McLennan 《Zoologica scripta》2001,30(1):59-77
Phylogenetic systematic analysis of 24 taxa representing the rhabdocoel platyhelminths, based on a suite of 89 morphological characters, produced two equally parsimonious trees, 181 steps long, with a consistency index (CI) of 0.69 and a rescaled consistency index (RCI) of 0.56, differing only with respect to that portion of the tree containing Umagillidae, Acholadidae, Graffillinae, Pseudograffillinae, Pterastericolidae and Hypoblepharinidae. Our results accommodate all previously proposed sister taxa to the Neodermata in a single clade in which ((Dalyelliidae + Temnocephalida) Typhloplanidae) is the sister group of ((Fecampiidae + Urastoma ) ( Udonella ((Aspidogastrea + Digenea) (Monogenea (Gyrocotylidea (Amphilinidea + Eucestoda)))))). Bootstrap and jackknife analyses indicate that the groupings of ((Dalyelliidae + Temnocephalida) Typhloplanidae) and of ((Fecampiidae + Urastoma ) ( Udonella ((Aspidogastrea + Digenea) (Monogenea (Gyrocotylidea (Amphilinidea + Eucestoda)))))) are highly robust, with the latter clade having a CI of 90% and RCI of 82%. Disagreements among previous analyses of these taxa have been due to the influence of missing data for critical characters in key taxa and differences in the taxa analysed, rather than any inherent weakness in the morphological data. Non-phylogenetic systematic approaches to homology assessment and misconceptions regarding phylogenetic systematic methodology are discussed. Recent analyses combining sequence data with a subset of approximately 60% of the morphological characters should be re-assessed using the entire morphological database. Even if Udonella is a monogenean, it is most parsimonious to suggest that the common ancestor of the Neodermata had a vertebrate–arthropod two-host life cycle. 相似文献
46.
Summary This workshop was an impromptu event, but the fact that a number of interesting problems were identified by the participants from the floor may indicate that it is worth repeating. If it is to be repeated, however, it is important that notice be given, and that the scope of the workshop be defined in advance, so that participants can be better informed and bring supporting data. The best approach would be to identify a convenor and define the scope of the workshop prior to the first circular for the next Seaweed Symposium; invitations could then be issued by the convenor for specific topics and data, and a very brief program could be issued with the third circular. Such a procedure may very well allow the identification of new areas for research. 相似文献
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Bactericidal effect of lactoferrin on Legionella pneumophila: effect of the physiological state of the organism 总被引:6,自引:0,他引:6
Lactoferrin has been previously shown to be bactericidal for Legionella pneumophila. The current study showed that CaCl2, Mg(NO3)2, and MgCl2, but not NaCl, blocked killing. Activity was pH dependent with the greatest activity at 5.0. Sensitivity of the organism was dramatically affected by the growth conditions. Log phase 12 h, broth-grown cells were most sensitive, with older cultures becoming more resistant. Plate-grown cells were completely resistant. Lactoferrin binding, as detected by immunofluorescence microscopy, was temperature dependent (no binding at 4 degrees C), but was independent of killing. 相似文献
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Ariella Oppenheim Avi Yaari Deborah Rund Eliezer A. Rachmilewitz David Nathan Corinne Wong Haig H. Kazazian Jr. Barbara Miller 《Human genetics》1990,86(2):175-180
Summary The mechanism for elevated production of fetal hemoglobin (Hb F) in a Druze patient with °-thalassemia intermedia was investigated. Heterozygous family members exhibited normal Hb F levels, suggesting that the increase in -gene expression in the propositus may be partly due to anemic stress. Erythroid progenitors of these family members cultured in vitro [burst forming units (erythroid); (BFUe)] showed elevated synthesis of Hb F, indicating the existence of a genetically determined intrinsic capacity for high Hb F production in this family. The propositus was found to be homozygous for a IVS2-position 1 mutation, on the background of Mediterranean haplotype I, which is not known to be linked to high Hb F production. Moreover, extensive molecular studies of the -globin gene cluster, including sequence analysis of the promoter regions of the -globin genes, did not reveal any cisacting mechanism that could account for the high Hb F production in the propositus. A young niece of the propositus with °-thalassemia major was recently discovered, who was homozygous for the same -globin allele and haplotype as the propositus. However, unlike her uncle, she does not have a high Hb F level and presents with a severe clinical course. Her inability to produce high Hb F suggests that the genetic determinant for increased -gene expression in the propositus is unlinked to the -globin gene cluster. 相似文献
50.
Frederick Errington is Aaaociate Professor of Anthropology, at Keene State College, New Hampshire. Deborah Gewertz is Professor of Anthropology, at Amherst College, Massachusetts. 相似文献