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The interactive effect of low P supply (0, 10, 20 and 40 M) and plant age on nodule number, mass and functioning (ureide analysis technique), vegetative growth and pod production were investigated in glasshouse-grown nodulated cowpea (Vigna unguiculata L.cv. Kausband) in sand culture. Compared with 40 M P, P stress (0 M P) or very low (10 M P) supply markedly impaired nodulation, allantoin and amino-N concentrations and weight of N solutes in xylem exudates. Consequently, P stress reduced top growth and pod yields by 48 and 90%, respectively. N solutes in xylem exudates and total plant N assayed by Kjeldahl technique (as estimates of N2 fixation) responded similarly to P supply. However, the relative ureide index [(ureide-N/ureide N+amino-N)×100] remained constant (99%), irrespective of P supply, indicating the plants' complete dependency on symbiosis for growth, without implying that growth was markedly increased by N2 fixation. Although P concentrations in plant tops, roots and nodules increased with P supply, N concentrations in these plant tissues were unaffected by P supply. The concentrations of N and P in the nodules were 2–2 1/2 times higher than in plant tops. P application interacted strongly with plant age, with the largest P effect evidently achieved at the early podding stage. The significance and implications of these results are discussed. 相似文献
3.
Chlorobium limicola forma thiosulfatophilum: Biocatalyst in the Production of Sulfur and Organic Carbon from a Gas Stream Containing H2S and CO2 总被引:3,自引:2,他引:1 下载免费PDF全文
Chlorobium limicola forma thiosulfatophilum (ATCC 17092) was grown in a 1-liter continuously stirred tank reactor (800-ml liquid volume) at pH 6.8, 30°C, saturated light intensity, and a gas flow rate of 23.6 ml/min from a gas cylinder blend consisting of 3.9 mol% H2S, 9.2 mol% CO2, 86.4 mol% N2, and 0.5 mol% H2. This is the first demonstration of photoautotrophic growth of a Chlorobium sp. on a continuous inorganic gas feed. A significant potential exists for applying this photoautotrophic process to desulfurization and CO2 fixation of gases containing acidic components (H2S and CO2). 相似文献
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DNA fragments of around 200 base pair (average size) have been covalently crosslinked with 8-methoxypsoralen under 365 nm UV light. The photoadduct, induced antibodies in rabbits with a titer of > 1:12,800 by direct bindng ELISA. Binding data showed that the induced antibodies are conformation-specific recognizing restricted conformational change at site of crosslinking. Human autoantibodies against DNA, bound not only to native DNA but to the photomodified DNA fragment as well. In addition, binding patterns of SLE sera obtained from different patients were remarkably similar, indicating the recognition of altered conformation of the modified polymer by naturally occurring SLE anti-DNA autoantibodies. 相似文献
6.
Joe F. Bozeman III Shauhrat S. Chopra Philip James Sajjad Muhammad Hua Cai Kangkang Tong Maya Carrasquillo Harold Rickenbacker Destenie Nock Weslynne Ashton Oliver Heidrich Sybil Derrible Melissa Bilec 《Journal of Industrial Ecology》2023,27(2):382-394
Now is the time to refocus efforts in urban research and design. A changing climate and extreme weather events are presenting unique challenges to urban systems around the world. These challenges illuminate the social barriers that accompany disruptive events such as resource inequities and injustices. In this perspective, we provide three research priorities for just and sustainable urban systems that help to address these matters. The three research priorities are: (1) social equity and justice, (2) circularity, and (3) digital twins. Conceptual context and future research directions are provided for each. For social equity and justice, the future directions are mandatory equity analysis and inclusionary practices, understanding and reconciling historical injustices, and intentional integration with diverse community stakeholders. For circularity applications, they are better metrics for integration, more robust evaluation frameworks, and dynamic modeling at multiple spatial and temporal scales. Future directions for digital twins include developing principles to reduce complexity, integrating model and system components, and reducing barriers to data access. These research priorities are core to meeting several of the United Nations Sustainable Development Goals (i.e., 1—No Poverty, 8—Decent Work and Economic Growth, 10—Reduced Inequalities, and 11—Sustainable Cities and Communities). Useful social and technical matters are discussed throughout, where we highlight the importance of prioritizing localized research efforts, provide guidance for community-engaged research and co-development practices, and explain how these priorities interact to align with the evolving field of industrial ecology. 相似文献
7.
The reproductive cycle in the population of Saccostrea cuccullatta (Born) from the coast of Karachi,Pakistan 总被引:6,自引:4,他引:2
M. Asif 《Hydrobiologia》1980,75(1):73-79
Periphytic diatom communities on clay tile and sterilized rock substrates were compared with those on natural substrates. Clay tiles yielded diatom communities with the least variability between replicate samples, and the greatest similarity to the natural substrate assemblage. The advantages of utilizing introduced substrate communities and problems encountered with their simulation of the natural substrate community are discussed. 相似文献
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The isolation of bergenin, 2-hydroxy-4-benzyloxyacetophenone and the related dimer and stilbene from Gnetum ula is reported. 相似文献
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Russian Journal of Bioorganic Chemistry - Pyridazines hold considerable interest relative to pharmacologically active molecules. The pyridazine compounds are exhibited different types of... 相似文献
10.
Yasir Iftikhar Mazhar Abbas Mustansar Mubeen Muhammad Zafar-ul-Hye Faheema Bakhtawar Sonum Bashir Ashara Sajid Muhammad Asif Shabbir 《Phyton》2021,90(4):1063-1074
Tristeza is a devastating viral disease in all the citrus growing countries throughout the world and has killed millions of citrus trees in severely affected orchards. The citrus species grafted on sour orange rootstock are affected
by this disease. Predominantly, the sweet orange, grapefruit and lime trees grafted on sour orange exhibit severe
symptoms like quick decline, vein clearing, pin holing, bark scaling and degeneration leading to variable symptoms. Symptomatic expression of Citrus tristeza virus (CTV) in different hosts has been attributed to virus isolates
which are from severe to mild. Different serological and molecular assays have been deployed to differentiate the
strains of CTV. Citrus tristeza virus is diversified towards its strains on the basis of biological, serological and
molecular characterization. Phenotypic expression is due to genetic alteration and different molecular basis have
now been adopted for strain differentiation. This review will give a brief idea about the different CTV isolates,
their characterization based on nucleic acid and serological assays. Different methods along with salient features
for strain characterization has also been reviewed. This review will also open the new aspects towards formulation
of management strategies through different detection techniques. 相似文献