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911.
Maria H. H?llfors Elina M. Vaara Marko Hyv?rinen Markku Oksanen Leif E. Schulman Helena Siipi Susanna Lehv?virta 《PloS one》2014,9(7)
Intentional moving of species threatened by climate change is actively being discussed as a conservation approach. The debate, empirical studies, and policy development, however, are impeded by an inconsistent articulation of the idea. The discrepancy is demonstrated by the varying use of terms, such as assisted migration, assisted colonisation, or managed relocation, and their multiple definitions. Since this conservation approach is novel, and may for instance lead to legislative changes, it is important to aim for terminological consistency. The objective of this study is to analyse the suitability of terms and definitions used when discussing the moving of organisms as a response to climate change. An extensive literature search and review of the material (868 scientific publications) was conducted for finding hitherto used terms (N = 40) and definitions (N = 75), and these were analysed for their suitability. Based on the findings, it is argued that an appropriate term for a conservation approach relating to aiding the movement of organisms harmed by climate change is assisted migration defined as follows: Assisted migration means safeguarding biological diversity through the translocation of representatives of a species or population harmed by climate change to an area outside the indigenous range of that unit where it would be predicted to move as climate changes, were it not for anthropogenic dispersal barriers or lack of time. The differences between assisted migration and other conservation translocations are also discussed. A wide adoption of the clear and distinctive term and definition provided would allow more focused research on the topic and enable consistent implementation as practitioners could have the same understanding of the concept. 相似文献
912.
913.
Effects of elevated carbon dioxide, ozone and water availability on spring wheat growth and yield 总被引:2,自引:0,他引:2
Håkan Pleijel Johanna Gelang Ebe Sild Helena Danielsson Suhaila Younis Per-Erik Karlsson Göran Wallin Lena Skärby Gun Selldén 《Physiologia plantarum》2000,108(1):61-70
Spring wheat (Triticum aestivum L. cv. Dragon) was exposed to elevated carbon dioxide (CO2), alone (1995) or in combination with two levels of increased ozone (O3) (1994) or increased irrigation (1996) during three successive growing seasons as part of the EU ESPACE‐wheat programme and conducted in open‐top chambers (OTCs) and ambient air (AA) plots at Östad, 50 km north‐east of Göteborg, Sweden. Doubling the CO2 concentration had a positive effect on grain yield in all 3 years (+21, +7 and +11%, respectively), although only statistically significant in 1994. That year was characterised by a warm and dry summer in comparison with 1995 and 1996, in which the summers were more humid and typical for south‐west Sweden. In 1994, the CO2‐induced increase in grain yield was associated with an increase in the duration of the green leaf area, a positive effect on straw yield and on the number of ears per square metre and a negative effect (?13%) on grain protein concentration. Harvest index was unaffected by the elevated CO2 concentration. The only statistically significant effect of elevated CO2 in 1995 was a decrease in the grain protein concentration (?11% in both CO2 concentrations), and in 1996 an increase (+21%) in the straw yield. In 1996 the soil water potential was less negative in elevated CO2, which is likely to reflect a lower water consumption of these plants. Addition of extra O3 significantly affected the grain yield (?6 and ?10%, respectively) and the 1 000‐grain weight negatively (?3 and ?6%). Statistically significant interactions between CO2 and O3 were obtained for the number of ears per unit area and for the 1 000‐grain weight. The 1 000‐grain weight was negatively affected by O3 in low CO2, but remained unaffected in the high CO2 treatment. There was a significant decrease (?6%) in the grain protein concentration induced by elevated irrigation. The chambers, compared with AA plots, had a positive effect on plant development and on grain yield in all 3 years. 相似文献
914.
915.
Post-translational regulation of cytosolic glutamine synthetase of Medicago truncatula 总被引:4,自引:0,他引:4
It was reported recently that the plastid-located glutamine synthetase (GS2) from Medicago truncatula is regulated by phosphorylation catalysed by a calcium-dependent protein kinase and 14-3-3 interaction. Here it is shown that the two cytosolic GS isoenzymes, GS1a and GS1b, are also regulated by phosphorylation but, in contrast to GS2, GS1 phosphorylation is catalysed by calcium-independent kinase(s) and the phosphorylated enzymes fail to interact with 14-3-3s. Phosphorylation of GS1a occurs at more than one residue and was found to increase the affinity of the enzyme for the substrate glutamate. In vitro phosphorylation assays were used to compare the activity of GS kinase, present in different plant organs, against the three M. truncatula GS isoenzymes. All three GS proteins were phosphorylated by kinases present in leaves, roots, and nodules, but to different extents, suggesting a differential regulation under different metabolic contexts. Cytosolic GS phosphorylation was found to be affected by light in leaves and by active nitrogen fixation in root nodules, whereas GS2 phosphorylation was unaffected by these conditions. Some putative GS-binding phosphoproteins were identified showing both isoenzyme and organ specificity. Two phosphoproteins of 70 and 72 kDa were specifically bound to the cytosolic GS isoenzymes. Interestingly, phosphorylation of these proteins was also influenced by the nitrogen-fixing status of the nodule, suggesting that their phosphorylation and/or binding to GS are related to nitrogen fixation. Taken together, the results presented indicate that GS phosphorylation is modulated by nitrogen fixation in root nodules; these findings open up new possibilities to explore the involvement of this post-translational mechanism in nodule functioning. 相似文献
916.
Fungal metabolic model for tyrosinemia type 3: molecular characterization of a gene encoding a 4-hydroxy-phenyl pyruvate dioxygenase from Aspergillus nidulans 下载免费PDF全文
da Silva Ferreira ME Savoldi M Sueli Bonato P Goldman MH Goldman GH 《Eukaryotic cell》2006,5(8):1441-1445
Mutations in the human HPD gene (encoding 4-hydroxyphenylpyruvic acid dioxygenase) cause hereditary tyrosinemia type 3 (HT3). We deleted the Aspergillus nidulans homologue (hpdA). We showed that the mutant strain is not able to grow in the presence of phenylalanine and that it accumulates increased concentrations of tyrosine and 4-hydroxyphenylpyruvic acid, mimicking the human HT3 phenotype. 相似文献
917.
Experiments were performed for adsorption of milk-based substrates onto anaerobic biomass at 35 degrees C. The influence of two parameters was studied, namely, the type of biomass (flocculent or granular) and the sludge adaptation to the substrate. It was found that flocculent sludge presented an adsorption capacity roughly 3 times higher than that of granular sludge. The adsorption data fit well with the Freundlich and Langmuir isotherms. Apparently, short-term sludge adaptation is not influential on the adsorption behavior. On the other hand, long-term adapted sludge showed a higher adsorption capacity than nonadapted sludge, which probably is an indirect effect of different microbial populations. These results suggest that the role of adsorption in the anaerobic treatment of complex substrates containing fat cannot be overlooked, especially for flocculent sludge systems, since organic matter accumulation could cause process failure due to biomass washout. 相似文献
918.
Empadinhas N Albuquerque L Henne A Santos H da Costa MS 《Applied and environmental microbiology》2003,69(6):3272-3279
The biosynthetic pathway for the synthesis of the compatible solute alpha-mannosylglycerate (MG) in the thermophilic bacterium Thermus thermophilus HB27 was identified based on the activities of recombinant mannosyl-3-phosphoglycerate synthase (MPGS) (EC 2.4.1.217) and mannosyl-3-phosphoglycerate phosphatase (MPGP) (EC 3.1.3.70). The sequences of homologous genes from the archaeon Pyrococcus horikoshii were used to identify MPGS and MPGP genes in T. thermophilus HB27 genome. Both genes were separately cloned and overexpressed in Escherichia coli, yielding 3 to 4 mg of pure recombinant protein per liter of culture. The molecular masses were 43.6 and 28.1 kDa for MPGS and MPGP, respectively. The recombinant MPGS catalyzed the synthesis of alpha-mannosyl-3-phosphoglycerate (MPG) from GDP-mannose and D-3-phosphoglycerate, while the recombinant MPGP catalyzed the dephosphorylation of MPG to MG. The recombinant MPGS had optimal activity at 80 to 90 degrees C and a pH optimum near 7.0; MPGP had maximal activity between 90 and 95 degrees C and at pH 6.0. The activities of both enzymes were strictly dependent on divalent cations; Mn(2+) was most effective for MPGS, while Mn(2+), Co(2+), Mg(2+), and to a lesser extent Ni(2+) activated MPGP. The organization of MG biosynthetic genes in T. thermophilus HB27 is different from the P. horikoshii operon-like structure, since the genes involved in the conversion of fructose-6-phosphate to GDP-mannose are not found immediately downstream of the contiguous MPGS and MPGP genes. The biosynthesis of MG in the thermophilic bacterium T. thermophilus HB27, proceeding through a phosphorylated intermediate, is similar to the system found in hyperthermophilic archaea. 相似文献
919.
Brain capillaries (microvessels) were isolated from the rabbit and bovine brain. Extensive morphological examinations were performed at the light and electron microscopical levels. The relative contribution of endothelium (52%), basal membrane (32%) and pericytes (16%) to the composition of the microvessel was assessed. The ability of the endothelium from bovine brains to maintain a membrane potential, i.e. to accumulate the lipophilic cation [3H]TPMP, was shown. The transmitter catabolizing enzymes MAO and AchE were shown to be, and COMT and GABA-T not to be associated with the microvessel fraction isolated from rabbits. 相似文献
920.
Alessandro K. Jordão Vitor F. Ferreira Emerson S. Lima Maria C.B.V. de Souza Eduardo C.L. Carlos Helena C. Castro Reinaldo B. Geraldo Carlos R. Rodrigues Maria C.B. Almeida Anna C. Cunha 《Bioorganic & medicinal chemistry》2009,17(10):3713-3719
This paper describes the synthesis, antiplatelet and theoretical evaluations of 10 N-substituted-phenylamino-5-methyl-1H-1,2,3-triazole-4-carbohydrazides (2a–j). These compounds were synthesized, characterized and screened for their in vitro antiplatelet profile against human platelet aggregation using arachidonic acid, adrenaline and ADP as agonists. Among NAH derivatives 2a–j, the compounds 2a, 2c, 2e, 2g and 2h were the most promising molecules with significant antiplatelet activity. 相似文献