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111.
Isolates of novel strains of Kashmir bee virus (KBV) were obtained from field-collected dead adults of Apis mellifera from honey bee colonies in Canada and Spain. They differed from other strains of KBV in their tendency to aggregate in dilute buffer solution and in containing only three proteins when analysed by SDS-polyacrylamide gel electrophoresis compared with five proteins resolved in the type strain of KBV from Apis cerana in India and six proteins in KBV strains from South Australia and New Zealand. Immunodiffusion tests and Western blotting studies indicated that the five virus isolates were serologically related and all were related to acute paralysis virus (APV). The world distribution of KBV strains and their apparent relationship with APV are discussed. 相似文献
112.
中国东亚飞蝗新类型蝗区──海南热带稀树草原蝗区的生态地理特征及其与大沙河蝗区比较 总被引:2,自引:0,他引:2
本文系统地对海南热带稀树草原螟区的生态地理结构特征进行了分析,说明本蝗区是Uvarov(1936)提出的飞蝗两类蝗区理论中.由于森林破坏而形成的一类蝗区,作者将它定名为"热带稀树草原蝗区"。这类蝗区在我国过去尚缺乏研究。文中进而根据本蝗区的成因、生态特征以及对蝗区的生态控制对策,分别与我国大陆的东亚飞蝗大沙河类型蝗区进行了比较。 相似文献
113.
大鼠中脑腹侧被盖区在睡眠-觉醒调节中的作用 总被引:1,自引:0,他引:1
本实验在31只清醒自由行动的雄性SD大鼠进行。结果如下:(1)双侧中脑腹侧被盖区(VTA)微量注射3.3nmol溴隐亭后第2—3h觉醒时间显著增加(P<0.01);6.6nmol溴隐亭有类似效果;0.66和1.33nmol溴隐亭无明显作用。(2)同样方法VTA微量注射2nmol和4nmolSCH23390后第2—3h觉醒时间明显减少(分别为P<0.01和P<0.05),但注射3.4nmol舒必利则无效。(3)红藻氨酸(0.3μg)双侧VTA注后一周,大鼠白天觉醒减少,夜间无明显变化。以上结果表明溴隐亭微量注射到VTA可能通过D1受体使多巴胺神经元活动增加而产生致觉醒作用;另外VTA中DA神经元对于维持日间的觉醒可能有紧张性作用。 相似文献
114.
Lauren Alfred Schroeder 《Entomologia Experimentalis et Applicata》1984,35(3):255-261
Gravimetric and a combination areal-gravimetric methods for determining dry matter budgets for leaf eating Lepidoptera were compared. The gravimetric method is based on dry weight/live weight ratios of the leaves fed to the larvae. In the areal-gravimetric method, the quantity of food offered to the larvae is determined from the area of leaf tracings and the dry matter content per unit area of the leaves. The areal-gravimetric method permits the use of larger leaf sprays and an open, gauze enclosed rearing chamber. There were no consistent differences in budget factors (growth, ingestion or egestion), nor were there any differences in the observed variability of the data attributable to the method used. However, the expected variability based on instrument precision for the gravimetric method is less than for the areal-gravimetric method. Experimental factors inherent in the gravimetric method introduce variability to the measurements that are not present in the areal method. Thirty to 60% of the variability in budget factors was attributed to intrinsic properties of the larvae, even though the larvae were taken from the same egg masses.
Résumé Les budgets en matière sèche consommée par des lépidoptères ont été comparés par les méthodes gravimétrique et planimétrique. La méthode gravimétrique est basée sur le rapport poids sec/poids frais de feuilles consommées par les chenilles. Avec la méthode planimétrique, la quantité d'aliment proposée aux chenilles est déterminée par les tracés de la surface des feuilles et le contenu de matière sèche par unité de surface des feuilles. La méthode de planimétrie permet l'utilisation de plus grands rameaux de feuilles et de cages d'élevage extérieures en gaze. Il n'y avait pas de différence appréciable dans les éléments du budget (croissance, ingestion et déjection), ni aucune différence dans la variabilité observée des données attribuable à la méthode utilisée. Cependant, la variabilité attendue d'après la précision des mesures avec la méthode gravimétrique est inférieure à celle de la méthode planimétrique. est inférieure à celle de la méthode planimétrique. Des éléments expérimentaux, inhérents à la méthode gravimétrique, introduisent une variabilité dans les mesures que l'on n'a pas avec la méthode planimétrique. 30–60% de la variabilité dans la consommation ont été attribués à des paramètres internes à la chenille, même quand elles provenaient toutes de la même ooplaque.相似文献
115.
S. V. Rao B. G. S. Rao 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1984,67(5):419-426
Summary Cytogenetic studies involving six species of spinous Solanums have been made using the parameters of crossability/fertility relationships and chromosome pairing in parental and derived hybrid genomes. These studies have made it possible to integrate hybrid reproductive performance with observed cytological phenomena and draw inferences on concerned intergenomic homeologies. It has been found that species' differences, as they exist, are ascribable to chromosome repatterning, in their divergence and maintenance as distinct taxa. In the light of these studies, the grouping of these species has to be reconsidered. 相似文献
116.
Summary A strong positive immunoreaction with an -endorphin antiserum occurs in two distinct sites of the goldfish and carp neurohypophysis. Fluorescent nerve terminals are found in the laminar nerve processes located in the rostral pars distalis, but the immunocytological reaction is mainly localised on the nerve processes of the posterior neurohypophysis lying between the intermediate lobe cells. Almost all the digitations of the neurohypophysis are strongly fluorescent. The immunoreactive fibres probably originate from the hypothalamus, where perikarya displaying the same immunoreaction have been found in the pars lateralis of the nucleus lateralis tuberis and in some minor centres. The possibility that the immunoreactive substances revealed on the neurohypophyseal processes may originate in the intermediate lobe cells is also discussed. It has now to be established if this hypothalamo-hypophyseal system contains a substance with endorphic properties or only some immunologically related substance devoid of the corresponding physiological activities. 相似文献
117.
W. Vader 《Hydrobiologia》1977,52(1):23-28
The amphibious land-molluse,Perforatella rubiginosa, is a common, wide-spread and characteristic inhabitant of the freshwater tidal region of the river Scheldt and its tributaries
in NW Belgium. The species occupies a rather narrow zone in the uppermost intertidal area, which is characterized by large
amounts of tidal drift covering the bottom, and usually by a luxuriant vegetation of tall, nitrophilous herbs, often withUrtica dioica dominant. Other characteristic molluscs of this zone areCarychium minimum, Oxyloma pfeifferi, O. sarsi, Deroceras laeve, Vitrea crystallina andZonitoides nitidus, locally alsoNesovitrea hammonis.
Communication nr. 143 of the Delta Institute for Hydrobiological Research, Yerseke, The Netherlands 相似文献
118.
Karin Valant-Vetschera 《Phytochemistry》1982,21(5):1067-1069
The flavonoid pattern of the monotypic Turkish genus Leucocyclus consists of C-glycosylflavones (isovitexin; isoorientin and derivatives; several di-C-glycosylapigenins; schaftoside, isoschaftoside and vicenin-3; lucenin-2), of flavonol 3-O-glycosides (quercetin and kaempferol 3-O-rhamnoglucoside) and trace amounts of luteolin 7-O-rhamnoglucoside. The systematic significance of the flavonoid diversification within Leucocyclus as well as possible relationships to other genera of the Anthemideae are discussed. 相似文献
119.
The sporophyte foot of the mossTimmiella barbuloides consists of an unistratose epidermis of transfer cells, a parenchymatous cortex, and a small central strand consisting only of hydroids. The parenchymatous tissue of the vaginula develops one layer of transfer cells opposite the foot, whose lower extremity extends into the gametophyte stem's central strand. From the bottom to the top of the foot the ultrastructure of the sporophyte transfer cells shows some gradual changes that appear related to a functional specialization of these cells. According to a centripetal gradient, the quantity of plastid starch progressively lessens in both vaginula parenchyma and foot cortex. the observed morphological patterns suggest that in the foot-vaginula complex nutrients are translocated radially up to the sporophyte central strand. 相似文献
120.
The vascular system of the leaves of Saccharum officinarum L. is composed in part of a system of longitudinal strands that in any given transverse section may be divided into three types of bundle according to size and structure: small, intermediate, and large. Virtually all of the longitudinal strands intergrade, however, from one type bundle to another. For example, virutually all of the strands having large bundle anatomy appear distally in the blade as small bundles, which intergrade into intermediates and then large bundles as they descend the leaf. These large bundles, together with the intermediates that arise midway between them, extend basipetally into the sheath and stem. Most of the remaining longitudinal strands of the blade do not enter the sheath but fuse with other strands above and in the region of the blade joint. Despite the marked decrease in number of bundles at the base of the blade, both the total and mean cross-sectional areas (measured with a digitizer from electron micrographs) of sieve tubes and tracheary elements increase as the bundles continuing into the sheath increase in size. Linear relationships exist between leaf width and total bundle number, and between cross-sectional area of vascular bundles and both total and mean cross-sectional areas of sieve tubes and tracheary elements. 相似文献