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Korochkin LI 《Ontogenez》2002,33(5):361-365
The studies of A.A. Neyfakh on morphogenetic nuclear activity are considered in the light of experimental embryology data.  相似文献   

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Basing his analysis on Kroeber's ‘The superorganic’ (1917 Kroeber, A. L. 1917. The superorganic.. American Anthropologist, 19: 163213. [Crossref] [Google Scholar]) and ‘Eighteen professions’ (1915 Kroeber, A. L. 1915. Eighteen professions.. American Anthropologist, 17: 28388. [Crossref] [Google Scholar]), Derek Freeman has put forward the notion of a ‘Boasian paradigm’, whereby Kroeber is alleged to have perpetuated the biology/culture split suggested by Boas. I argue, instead, that there is a strong innatist element in Kroeber's writings throughout his long career; and that the articles noted above need to be placed in the social and intellectual contexts of their time, particularly the encroachment of the eugenics movement on social theory and its application to immigration restriction.  相似文献   

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From pollen grains of Typha davidiana, T. latifolia, T. angustata the same eight flavonoids have been isolated. They are identified as naringenin I, isorhamnetin II, quercetin III, isorhamnetin-3-O-(2G-α-L-rhamnopyranosyl)-rutioside IV, quercetin-3-O-(2G-α-L-rhamnopyranosyl)-rutinosida, V, isorhamnetio-3-O-rutinoside VI, isorhamnetino-3-O-neohesperidoside VII, kampferol-3-O-neohesperidoside VIII. Flavonoids of pollen grains of five species of Typha, including the above three species, were analysed by TLC with the result showing that the constituents in the pollen grains of the five species are very similar. The chemical comparison among Typha and Sparganium and 16 possibly related families shows that Typha is different from Pandanaceae or Pandanales and is similar to Restionaceae, Flagellariaceae, Juncaceae and Cyperaceae in some respects. Typha and Sparganium are very similar in many respects, and they could be treated in the same family, Typhaceae, which merit the rank of order, Typhales.  相似文献   

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对毛茛科铁线莲属Clematis L.的单性铁线莲组sect. Aspidanthera Spach s.l.进行了全面修订,确定此组共含72种和15变种,这些种被归类于6个亚组中,其中包括首次描述的1系、5种和2变种,以及做出的2新等级.对单性铁线莲组的分类学简史和地理分布做了介绍.写出了组、亚组、系的形态特征和地理分布,分亚组检索表及各亚组的分种检索表;以及各种植物的形态描述、地理分布、生长环境等,并附有多幅插图.在研究了此组全部种类的标本之后,观察到此组几个重要形态特征的演化趋势(1)萼片在数目上由4枚演变到8枚,在开展方向上由平展到直上展,在形状上由长圆形到狭条形,在长度上由比雄蕊稍长到2-4倍长于雄蕊,其卷叠式由镊合状到次生的覆瓦状;(2)花药药隔顶端由不具突起到具短或长的突起;(3)雌花退化雄蕊的数目由多数到定数、少数,以至完全消失;(4)花序自当年生枝的叶腋发生演变到与数叶同自老枝的一腋芽中发出.根据上述演化趋势推断本组各亚组间的亲缘关系如下subsect. Dioicae (34种,广布于北美洲和南美洲)的花构造(萼片4,镊合状排列,平展,通常呈长圆形,稍长于雄蕊或近等长,外面边缘被短绒毛;雄蕊花药呈长圆形,药隔顶端无突起;雌花具多数退化雄蕊;花序自当年生枝的叶腋发出)与具两性花的威灵仙组欧洲铁线莲亚组sect. Clematis subsect. Clematis 的花极为相似,区别主要在于本亚组的花为单性,由此判断subsect. Dioicae可能是单性铁线莲组sect. Aspidanthera的原始群,源出于欧洲铁线莲亚组.本组的第二亚组subsect. Lasianthae(2种,分布于北美西南部)与subsect. Dioicae 在亲缘关系上极为相近,区别只在于其花序或具花当年生枝与数叶一同由老枝的一个腋芽中发出,此亚组当是从subsect. Dioicae衍生出的一个小群.第三亚组subsect. Microphyllae(7种,特产澳大利亚)也与subsect. Dioicae相近缘,但此亚组的萼片变狭长,多呈条形或狭条形,常2-4倍长于多少变短的雄蕊,雌花的退化雄蕊数目变少,16-2枚,根据这些进化特征,推测此亚组也源出于subsect. Dioicae.第四亚组subsect. Aristatae (16种,分布于澳大利亚、新几内亚及邻近岛屿)与subsect. Microphyllae 在亲缘关系上相近,但本亚组的花药药隔顶端具短或长的突起而不同,根据此进化特征,推测本亚组系由后者演化而出.第五亚组subsect. Hexapetalae (11种,特产新西兰)的花构造与分布于澳大利亚的subsect. Microphyllae相似,但其萼片为覆瓦状排列,外面边缘不被短绒毛,在多数种多于4枚,为5-8枚而不同.据Godley 的研究,本亚组中的C. afoliata的花有4枚萼片,排成2轮,每轮的2枚萼片均为近镊合状排列;另外,在C. paniculata花的6枚萼片中,4枚为覆瓦状排列,其他2枚有时内向镊合状排列.从上述情况可见此亚组的萼片覆瓦状卷叠式可能是由镊合状卷叠式演变而来的一种次生现象,并由此推测,此亚组可能与subsect. Microphyllae相同,也源自美洲的subsect.Dioicae.最后一个亚组subsect. Insidiosae(2种,特产马达加斯加)的雌花萼片直上展,退化雄蕊完全消失,具有这些进化特征,当是单性铁线莲组的进化群,可能源出自具定数或少数退化雄蕊的subsect. Microphyllae.  相似文献   

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Aberrations of chromosome occur in different malignancies, but they are more frequent in lymphoproliferative ones than in the others. In this study here four out of five T-zone lymphomas had abnormalities of chromosome 3. This lead to the question of whether aberrations of chromosome 3 might be a marker of T-cell lymphomas. The conclusion which can be drawn from the cases described in the literature, the own unpublished cases, and these four T-zone lymphomas is that abnormalities of chromosome 3 cannot be regarded as a discriminative marker of T-cell derived malignancies. It is suggested that the relationship between chromosome aberrations and type of disease is not necessarily a direct one. One possible model of the genesis of chromosome aberrations in malignant diseases is presented.  相似文献   

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In this paper, we analyzed the phylogeny of the section Bulbocodii (genus Narcissus; Amarillydaceae) using the matK and trnL-F fragments of cpDNA in order to review the validity of the recognized taxa. Our results indicate that Narcissus obesus should be considered a valid species, and that N. blancoi is a distinct taxon. In addition, seven previously recognized species, N. juressianus, N. subnivalis, N. graellsii, N. conspicuus, N. citrinus, N. nivalis, and N. quintanilhae, should be assigned to an infraspecific rank under N. bulbocodium, as they are not valid species. In addition, we analyzed the distribution of the three morphological characters widely used in the systematics of this section and found that their variation does not agree with the phylogenetic results, rendering these characters limited taxonomical utility. This result suggests that the section Bulbocodii shows high morphological lability, which can explain the proliferation of nominal species.  相似文献   

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1. A defined medium was devised for use in washed-cell experiments with post-exponential-phase cultures of Bacillus amyloliquefaciens. The medium allowed alpha-amylase to be secreted, bacterial concentration to increase and l-[U-(14)C]valine to be incorporated into protein at a linear rate, which was the same as in a post-exponential-phase culture, for up to 6h. 2. Determination of the specific radioactivity of l-[U-(14)C]valine in the medium, the intracellular amino acid pool, the cellular protein and the isolated alpha-amylase, after a 3h incubation of washed cells in the defined medium, showed that at least 76% of the alpha-amylase secreted was synthesized de novo. 3. By isolating the alpha-amylase formed during a 6h incubation in the presence of l-[U-(14)C]valine it was shown that the specific radioactivity of the N-terminal valine, within the limits of experimental error, was the same as that of the total valine residues from the complete alpha-amylase molecule. 4. A consideration of these results in relation to the whole literature on the subject strongly supports the idea that there is no reason to suppose that extracellular alpha-amylase is formed from a high-molecular-weight precursor in B. amyloliquefaciens and closely related organisms with identical characteristics of exoenzyme secretion.  相似文献   

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