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11.
Responses of the epidermal diffusive conductance (gep) to irradiance (I) during ontogeny of primary bean leaves or during their wilting were followed. Effects ofI, leaf age and leaf water potential (Ψw) as well as interactive effects (I × leaf age andI × Ψw) ongep were statistically significant. 相似文献
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The strength of the H-Y antigen on thymus cells and on skin was compared in differentH-2-congenic mouse strains using a host-versus-graft reaction popliteal lymph node assay, and skin grafts from males of parental strains grafted to F1 hybrid females. The results revealed considerable differences in the strength of the H-Y antigen among different congenic strains; these differences demonstrate the effect of theH-2-linked gene on the expression of the H-Y antigen. The linkage withH-2 was also confirmed in tests with segregating F2 generations. In the strains bearing recombinantH-2 haplotypes, the strength of the H-Y antigen is similar to that of parental strain from which the recombinant received itsK end, and the responsible gene (or genes) map to the left ofI-C. The effect of theH-2-linked gene(s) on thymus cells and skin is different. The gene linked to theK end ofH- 2b determines a strong H-Y antigen on thymus cells, but a relatively weak H-Y antigen on skin. The gene linked to theK end ofH- 2k determines a weak H-Y antigen on thymus cells, but a strong H-Y antigen on skin. The gene linked to theK end ofH- 2d determines a weak H-Y antigen on both thymus cells and skin. Our observations raise the possibility that the structural gene for the H-Y antigen is linked toH-2. Alternative (but not exclusive) explanations invoke regulatory effects ofH-2 on the expression of the H-Y antigen, possibly by means of the control of the cellular andogen receptors. 相似文献
14.
Direct PCR of washed blood cells. 总被引:1,自引:0,他引:1
We report a simple and rapid method for direct DNA amplification of washed blood cells by PCR. Small samples (2-100 microliters) of blood were washed, the cells resuspended in a buffer and used directly for PCR after boiling. Amplification of a specific DNA sequence of the human transthyretin gene, directed by the primers, was successfully performed. The method gives comparable results to amplifications made by purified DNA from blood. 相似文献
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Chad Husby 《The Botanical review》2013,79(2):147-177
Horsetails are unique survivors of a very ancient group of vascular plants, the Sphenophyta, which has a history reaching back to the Upper Devonian. Despite the striking conservatism of Equisetum architecture and anatomy and the small number of species (15) in the modern flora, their ability to thrive under a wide range of conditions is remarkable. This is due to a diverse suite of adaptations that allow tolerance of disturbance, soil anoxia, high metals, and salinity, along with efficient nutrient uptake and nitrogen fixation. The giant horsetails represent the largest living Sphenophyta and provide insights into how their larger ancestors lived and how this ancient lineage has managed to survive in tropical regions. 相似文献
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Jarmila Solárová 《Biologia Plantarum》1970,12(2):110-116
Values of the water saturation deficit (WSD) for hydroactive stomatal movements of kale leaves were estimated using the method of transpiration curve analysis. Stomata of young leaves started closing at WSD values of 5 to 6 per cent and were completely closed at 18 to 20 per cent WSD. During maturation and ageing of leaves these WSD values increased to 12.5 and 18 to 23 per cent respectively. Thus the stomatal reaction is more sensitive to changes in WSD in adult leaves than in young ones. After maturation is attained both values decrease. In apparently withering leaves the individual phases of transpiration curves can barely be distinguished, probably for the reason that even under optimal conditions their stomata remain half-closed and at high WSD values an incomplete closing of the aperture occurs. The injured cuticle of withering leaves affects the shape of the transpiration curve as well. 相似文献
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Brett Jestrow William Cinea Brígido Peguero Chad Husby Javier Francisco‐Ortega 《Curtis's Botanical Magazine》2021,38(1):3-18
Clavija domingensis Urb. & Ekman was one of the many Haitian endemics that were described based on collections made by the great Swedish botanist Leonard Ekman between 1924 and 1928. The species is Critically Endangered sensu IUCN (criteria c2a(i); D) and it is currently the focus of conservation initiatives in Jardin Botanique des Cayes (Haiti), Jardín Botánico Nacional Dr. Rafael M. Moscoso (Dominican Republic), and Fairchild Tropical Botanic Garden (U.S.A.). Now known from only six localities from southern Haiti, each locality only represents a single individual. The species is illustrated based on plants grown in Fairchild Tropical Botanic Garden. 相似文献
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Yahya Sohrabi Helena Havelková Tetyana Kobets Matyá? ?íma Valeriya Volkova Igor Grekov Ta?ána Jaro?íková Iryna Kurey Jarmila Vojtí?ková Milena Svobodová Peter Demant Marie Lipoldová 《PLoS neglected tropical diseases》2013,7(7)