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301.
新疆洛浦山普拉古墓人骨的种系问题   总被引:4,自引:4,他引:0  
新疆洛浦山普拉古墓地的古代居民在体质形态特点上应是接近长颅欧洲人种地中海东支类型而不是具有“大蒙古人种大部分特征,但也有欧罗巴人种一些较明显特征”的混血类型。  相似文献   
302.
稀土元素对油菜菌核病菌生长及其生化性状影响的研究   总被引:12,自引:2,他引:10  
研究了氧化镧 (La2 O3 )对油菜菌核病菌 (Sclerotiniasclerotiorum ,Ss)生长及其生化性状的影响 .结果表明 ,La2 O3 浓度在 3 0~ 45 0mg·L-1时 ,固体培养和液体培养中对Ss生长均呈明显抑制作用 ,且生长抑制率 (Y)随La2 O3 浓度增加而相应增加 .液体培养中油菜菌核病菌产生的果胶酶活性随溶液中La2 O3 浓度增加而相应增加  相似文献   
303.
Recent strong El Niño‐Southern Oscillation (ENSO) signals have been identified in precipitation records from the Iberian Peninsula. Interannual association with ENSO accounts for more than half the total annual variance in selected stations of the south‐east, with ENSO leading rainfall by one year. In contrast, association with the North Atlantic Oscillation (NAO) at the Westernmost stations is much lower (25%). The potential of simple linear models is tested in the ENSO‐sensitive area, suggesting high capability of the Southern Oscillation Index (SOI) for predicting interannual rainfall fluctuations (mainly droughts and floods). Wine quality is associated with several factors, e.g. grape variety, soil type and processing, which can be considered invariable, mainly due to the strict regulations imposed by the quality regulating councils. Climate, however, has a great influence on resulting wine quality, and represents the most important source of variability at both short (day‐to‐day) and long (interannual) time scales. Over the last 30 years, high‐quality harvests in the five main wine regions in Spain, show a high probability (P < 0.0002) of being associated with an El Niño event occurring the same year or the year before. NAO influence is not significant during the same period. Thus, apart from considering the role of local climatic conditions in certain regions, which favour the production of excellent wines, larger‐scale climatic phenomena appear responsible for the year‐to‐year variations in quality.  相似文献   
304.
A technique for studying the binding of La3+ to synaptosomes in a double-beam spectrophotometer, using murexide as indicator, is described. The binding of La3+ was very rapid and Scatchard plots revealed two components, with KD values of 0.6 and 27 microM in a Na+-free medium (sucrose medium) and 2.3 and 63 microM in an ionic medium containing 135 mM Na+. The binding of the cationic dye ruthenium red (RuR) showed only one site, with a KD of 3.7 microM. La3+ binding was partially inhibited by RuR and vice versa, and La3+ was also capable of partially displacing RuR previously bound to the synaptosomes, particularly in the sucrose medium. The release of labeled gamma-aminobutyric acid (GABA) stimulated by K+ depolarization was inhibited by La3+ concentrations at or above 1 microM, in the ionic medium, whereas in the sucrose medium 2.5 microM or higher La3+ concentrations notably stimulated the spontaneous release of both GABA and glutamic acid. It is concluded that La3+ and RuR share at least one type of binding site, which is probably the high-affinity La3+ site. Since both La3+ and RuR at low concentrations have been shown to block the depolarization-induced Ca2+ entry in synaptosomes, this site might be related to the voltage-dependent Ca2+ entry involved in neurotransmitter release.  相似文献   
305.
A cell division-active protein from E. coli   总被引:11,自引:0,他引:11  
A purification procedure for a protein obtained from an pathogenic strain of E. coli is described. The protein-called CNF-is active in inhibiting the duplication of cultured mammalian cells. Since nuclei division is apparently normal, treatment of cultured cells with CNF leads to the formation of gigantic, polynucleated cells. The purified protein is chromatographically and electrophoretically homogeneous. A partial characterization of CNF protein is also given.  相似文献   
306.
The Dictyostelium discoideum lectins, discoidin I and discoidin II, and the endogenous ligands to which they bind were immunohistochemically localized in sections of this organism at successive stages of development. For these studies, an axenic strain, AX3, was grown in a macromolecule-depleted medium rather than on bacteria, which themselves contain discoidin-binding ligands. Discoidin I-binding sites (endogenous ligands) in sections of D. discoideum were concentrated in the slime coat around aggregates, whereas discoidin II-binding sites were observed in a vesicle-like distribution in prespore cells and also in spore coats. In contrast, discoidin II did not bind to the slime coat and discoidin I bound relatively poorly to prespore cells and spore coats. The distributions of the endogenous lectins themselves were the same in axenically grown cells as previously reported for cells raised on bacteria. Discoidin I was concentrated in the slime coat and around stalk cells, and discoidin II was prominent in and around prespore cells. The congruent localization of each lectin with its endogenous ligand suggests that discoidin I normally functions in association with glycoconjugates in the slime around aggregates, and discoidin II with the galactose-rich spore coat polysaccharide.  相似文献   
307.
The first fossil remains of marmosets, an isolated incisor, premolar, and molar, all similar in size toCallithrix species, have been discovered in the middle Miocene La Venta fauna of Colombia. The M1 is referred to a new genus and species,Micodon kiotensis, characterized by a fully developed hypocone and low occlusal relief. The P4 and I1 resemble those ofCallithrix, suggesting a close affinity with callitrichin marmosets. In combining small size with a four-cusped morphology,Micodon demonstrates the shortcomings of typological definitions of platyrrhine families and suggests that small body size may have preceded the tricuspid molar pattern in marmoset evolution. The 14- to 15-Ma date for the La Venta suggests that marmosets are an at least moderately ancient radiation, contrary to estimates based upon the molecular clock.  相似文献   
308.
Concluding remarks It is important to remember that the merits of the different approaches to epitope mapping should be judged against the purpose of the study. A peptide specifically recognized by nearly all sera containing a certain autoimmune specificity [20, 21, 26], would most likely be selected for the detection of the anti-linear/continuous epitope fraction among those autoantibodies and could be highly useful for diagnostic purposes. This is true even if a majority of the antibodies were directed against conformational/discontinuous protein epitopes. If the purpose is to study the induction or maintenance of the autoimmune response, one would also have to look at and account for the conformation-dependent autoantibodies. There is also the possibility that some pathogenic autoantibodies could constitute a small fraction requiring the complete nucleic acid-protein complex as an antigen. In that case, the pathogenic epitope would not be identified nor mapped using the techniques discussed in this review.  相似文献   
309.
A large number of weakly germinated hulled barley grains was found during archaeobotanical analyses from the early Celtic settlement excavations at Eberdingen-Hochdorf in southwest Germany (ca. 600 – 400 BC). These grains seem to represent deliberate germination, due to the purity of the find and its unusual archaeological context. The possibility of deliberate malting which could be connected with beer brewing is discussed. Recent germination and charring experiments show that the consistently weak traces of germination on the charred subfossil grains from Hochdorf are enough to indicate malted grains. A comparison of the archaeobotanical remains with the written and archaeological sources shows that evidence of beer brewing from excavations is very scarce. There is practically no clear proof of brewing, while written sources and indirect suggestions are abundant. Neither archaeological finds nor either written or iconographic sources give exact details about the prehistoric brewing technology of the early Celts. The archaeological finds from Hochdorf seem to be the result of deliberate malting of hulled barley for the purpose of Celtic beer brewing.  相似文献   
310.
Black carbonate rocks («ampelitic limestones)exposed in la Meignanne, NW of Angers, Massif Armoricain, as tectonic lenses within a complex tectonic structure of grey Pragian limestones are assigned from Bivalvia and Chitinozoa to the Upper Silurian and Lowermost Devonian. Biostratigraphical and paleoecological analyses show that the Silurian-Devonian boundary in this area is developed in offshore facies and that it may be correlated directly with the international stratotype of the Prague Basin (Barrandian, Bohemia). Paleogeographical communication between the two areas is indicated by 28 species of bivalves in common from two Pridolian assemblages (with Cheiopteria bridgei and with Snoopyia insolita) and one Lochkovian (with Antipleura bohemica). Stratigraphical correlation with the Prague Basin is also based on the chitinozoan zonal index species for the Uppermost Pridolian (Urnochitina urna) and Lowermost Lochkovian (Eisenackitina bohemica). A Lochkovian age is further supported by the discovery of Monograptus uniformis uniformis in the assemblage with Antipleura bohemica. A Ludlovian age is indicated by the occurence of «Hemicadium elevatum and an abundance of the ostracode Entomozoe (Richteria) migrans, which is an index species for the Middle Ludlovian in Bohemia.  相似文献   
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